JP2019192518A - Power storage device - Google Patents

Abstract

To provide a power storage device capable of restraining interference of a corner of the case body and an insulation sheet, when inserting an electrode assembly into the case body.SOLUTION: An insulation sheet 33 has a bottom side insulation 34 for insulating the bottom wall of the case body 13 and the bottom face of an electrode assembly 12, a first insulation 35 for insulating the first end face 12b of the electrode assembly 12 from the case body 13, a second insulation 36 for insulating the second end face 12c of the electrode assembly 12 from the case body 13, and a first chamfer 34c and a second chamfer 37 for insulating the corner of the electrode assembly 12 from the corner 13e of the case body 13.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power storage device including a bottomed cylindrical insulating sheet that insulates an electrode assembly from a case.

  Vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles) are equipped with secondary batteries as power storage devices that store the power supplied to the driving motor. The secondary battery includes, for example, an electrode assembly having a positive electrode and a negative electrode, and a case for housing the electrode assembly. The case includes a case main body that accommodates the electrode assembly, and a lid that closes an opening of the case main body. Moreover, in order to insulate an electrode assembly and a case, the insulating sheet which covers an electrode assembly may be provided. The insulating sheet is formed into a cylindrical shape with a flat bottom by assembling a sheet having a developed shape in advance, and the cylindrical insulating sheet with the bottom is accommodated in the case, and an electrode assembly is formed on the insulating sheet. A solid is accommodated (see, for example, Patent Document 1).

JP2015-32386A

  However, a metal case made of aluminum or the like, which is excellent in durability, is frequently used for the case of the secondary battery. In such a case, the inner surfaces of the four corner portions of the peripheral wall of the case main body each have a planar arc shape. In the manufacturing process of the secondary battery, there is a step of inserting the electrode assembly into the case main body, and the electrode assembly is inserted into the case main body while being accommodated in the insulating sheet. If each corner of the case body interferes with the corner of the insulating sheet facing each corner, the electrode assembly cannot be inserted into the case body, so the corner of the insulating sheet and the corner of the case body do not interfere. It is necessary to do so. In this case, the insulating sheet is reduced in size, and the electrode assembly accommodated in the insulating sheet is also reduced in size, which is not preferable because the battery capacity is reduced.

  The objective of this invention is providing the electrical storage apparatus which can suppress interference of the corner part and insulating sheet of a case main body when inserting an electrode assembly in a case main body.

  A power storage device for solving the above problems includes an electrode assembly in which a plurality of positive electrodes and negative electrodes are alternately stacked, a rectangular box-shaped case body that accommodates the electrode assembly, and the case A power storage device comprising a case having a lid that closes an opening of a main body, and a bottomed cylindrical insulating sheet that insulates the electrode assembly from the case, wherein the electrode assembly has a rectangular bottom surface And in the electrode assembly, a direction in which the positive electrode and the negative electrode overlap is defined as a stacking direction, and the stacking direction is a plane direction along the bottom surface. A direction perpendicular to the direction is defined as a width direction, and the insulating sheet includes a flat bottom insulating portion disposed between a bottom wall of the case body and a bottom surface of the electrode assembly, and a stacking direction of the electrode assemblies Both end faces A first insulating portion disposed between the case main body, a second insulating portion disposed between both end faces in the width direction and the case main body, and the case main body provided on the bottom insulating portion. And a second chamfered portion connected to the first insulating portion and the second insulating portion, wherein the first chamfered portion is the second chamfered portion. The gist is that it is connected to the department.

  According to this, the electrode assembly can be insulated from the case by the bottom insulating portion, the first insulating portion, the second insulating portion, and the second chamfered portion of the insulating sheet. In addition, when the electrode assembly covered with the insulating sheet is inserted into the case body, the first chamfered portion of the bottom-side insulating portion suppresses the insulating sheet from interfering with the corner portion of the case body. The covered electrode assembly can be inserted into the case body. Therefore, in order to suppress interference between the case main body and the insulating sheet, it is not necessary to downsize the entire insulating sheet, and it is not necessary to downsize the electrode assembly accommodated in the insulating sheet. There is no need to reduce it.

Moreover, about the electrical storage apparatus, the dimension of the whole chamfered part which consists of a said 1st chamfer part and a said 2nd chamfer part may be more than the thickness of the said bottom side insulating part.
According to this, after inserting the electrode assembly covered with the insulating sheet into the case main body, the first chamfered portion of the bottom insulating portion prevents the insulating sheet from interfering with the corner portion of the case main body. Moreover, it can suppress that an insulating sheet interferes with the corner part of a case main body by the 1st chamfering part and the 2nd chamfering part.

In the power storage device, the bottom-side insulating portion may include an outer bottom surface that contacts the bottom wall of the case body, and the dimension of the chamfered portion from the outer bottom surface may be 1 mm.
According to this, by the 1st chamfering part and the 2nd chamfering part, many parts chamfered to the insulating sheet can be secured, and the insulating sheet can be prevented from interfering with the corner part of the case body.

  In the power storage device, the electrode assembly includes a first end face as both end faces in the stacking direction, a second end face as both end faces in the width direction, and the corner portion, and the insulating sheet Are bent, the bottom insulating portion covering the bottom surface, the first insulating portion covering the pair of first end surfaces, the second insulating portion covering the pair of second end surfaces, and the corners. In the state where the insulating sheet is unfolded, including the second chamfered portion that covers a portion, and the overlapping portion that covers a portion of the second end surface on the bottom surface side so as to overlap the second insulating portion, The insulating sheet extends from a pair of second edges perpendicular to the first edge, the first insulation extending from a pair of first edges facing the bottom insulating part. The overlapping portion, the second chamfered portion extended from the first chamfered portion, and the adjacent second surface And a surplus part including the second insulating part, and the insulating sheet includes boundary lines between the bottom insulating part and the first insulating part, and the bottom insulating part. And the first chamfered portion located between the second chamfered portion and the second chamfered portion, and bend along each boundary line between the overlapped portion and the surplus portion, and the second chamfered portion and the surplus portion By folding each boundary line and folding the surplus portions facing each other, folding each boundary line between the overlapping portion and the bottom insulating portion to overlap the second insulating portion and the overlapping portion, It may be a bottom cylinder.

  According to this, the insulating sheet is formed by bending each boundary line and folding the surplus portions so that the second insulating portion and the overlapping portion overlap each other. For this reason, a clearance gap is not formed in the insulating sheet which covers the 1st end surface of the electrode assembly, the 2nd end surface, and a bottom face, but insulation is improved.

  In the power storage device, the electrode assembly includes a first end face as both end faces in the stacking direction, a second end face as both end faces in the width direction, and the corner portion, and the insulating sheet Are bent, the bottom insulating portion covering the bottom surface, the first insulating portion covering the pair of first end surfaces, the second insulating portion covering the pair of second end surfaces, and the corners. In the state where the insulating sheet is unfolded, including the second chamfered portion that covers a portion, and the overlapping portion that covers a portion of the second end surface on the bottom surface side so as to overlap the second insulating portion, The insulating sheet extends from a pair of second edges perpendicular to the first edge, the first insulation extending from a pair of first edges facing the bottom insulating part. An overlapping portion, the second chamfered portion extending from the first chamfered portion, and the adjacent first chamfered portion It is located between the chamfered portion and the overlapping portion, and includes a surplus portion including the second insulating portion, and further includes a notch at a boundary between the pair of surplus portions and the overlapping portion, Bending each boundary line between the bottom insulating part and the first insulating part, each boundary line between the surplus part and the second chamfered part, and each boundary line between the bottom insulating part and the overlapping part, Each boundary line between the overlap portion and the bottom insulating portion is folded while folding the surplus portions facing each other by folding each boundary line between the second chamfered portion and the surplus portion. The bottomed cylindrical shape may be formed by folding the second insulating portion and the overlapping portion by bending using a notch.

According to this, since the notch was provided in the insulating sheet, it is easy to perform the operation of overlapping the overlapping portion while folding the surplus portion by using the notch.
In the power storage device, the electrode assembly includes a first end face as both end faces in the stacking direction, a second end face as both end faces in the width direction, and the corner portion, and the insulating sheet Are bent, the bottom insulating portion covering the bottom surface, the first insulating portion covering the pair of first end surfaces, the second insulating portion covering the pair of second end surfaces, and the corners. A second chamfered portion that covers a portion, and in a state where the insulating sheet is deployed, the insulating sheet extends from a pair of first edge portions facing each other of the bottom insulating portion. A first insulating portion; a second insulating portion extending from a pair of second edge portions orthogonal to the first edge portion; and a second chamfering portion extending from the first chamfering portion. The insulating sheet includes boundary lines between the bottom insulating portion and the first insulating portion, and the bottom insulating portion. Each of the boundary lines between the first insulating portion and the second insulating portion, and the first insulating portion that is bent along the first chamfered portion located between the bottom insulating portion and the second chamfered portion, The bottomed cylindrical shape may be formed by bonding the second chamfered portion, the adjacent second chamfered portion and the second insulating portion with an adhesive sheet.

  According to this, the insulating sheet before being bent is composed of the bottom-side insulating portion, the first insulating portion, the second insulating portion, and the second chamfered portion, and is necessary for wrapping the electrode assembly. Consists of only parts. For this reason, in an insulating sheet, since an excessive part does not exist when it bends and it is not necessary to bend an excessive part, it is easy to manufacture an insulating sheet in a bottomed cylinder shape.

  In the power storage device, the electrode assembly includes a first end face as both end faces in the stacking direction, a second end face as both end faces in the width direction, and the corner portion, and the insulating sheet Is bent to cover the bottom insulating portion covering the bottom surface, the first insulating portion covering the pair of first end surfaces, the second insulating portion covering the pair of second end surfaces, and the corner portion. The first insulating sheet extending from a pair of opposing first edges of the bottom insulating part in a state where the insulating sheet is unfolded. Part, the second insulating part extended from a pair of second edge parts orthogonal to the first edge part, and located between the adjacent first insulating part and the second insulating part, and the second surface A surplus portion including a take-up portion, and a boundary between the first insulating portion and the second insulating portion and the surplus portion. The insulating sheet includes a boundary line between the bottom insulating part and the first insulating part, a boundary line between the bottom insulating part and the second insulating part, and the bottom insulating part. Each boundary line between the portion and the surplus portion is bent using the notch, and the adjacent first portion is overlapped with the second insulating portion in a state where the portion other than the second chamfered portion is overlapped with the surplus portion. The bottomed cylindrical shape may be formed by bonding one insulating portion and the second chamfered portion, and the adjacent second chamfered portion and the second insulating portion with an adhesive sheet.

  According to this, in the insulating sheet in a state before being bent, the surplus portion is bent using the cut, so that the insulating sheet is not cut off and the material yield is not deteriorated.

  In the power storage device, the electrode assembly includes a first end face as both end faces in the stacking direction, a second end face as both end faces in the width direction, and the corner portion, and the insulating sheet Includes the bottom insulating portion that covers the bottom surface by being bent, the first insulating portion that covers the pair of first end surfaces, and the second insulating portion that covers the pair of second end surfaces. In the state where the insulating sheet is unfolded, the insulating sheet is orthogonal to the first insulating portion extended from a pair of first edge portions facing the bottom insulating portion, and the first edge portion. The second insulating portion extending from the pair of second edges, and the insulating sheet includes boundary lines between the bottom insulating portion and the first insulating portion, and the bottom insulating portion and the Bending each boundary line with the second insulating portion, the adjacent first insulating portion and the first insulating portion And the bottomed cylindrical shape bridging the adhesive sheet and the insulating portion, may form the second chamfered portion by the adhesive sheet.

  According to this, in the insulating sheet, the second chamfered portion is formed by the adhesive sheet spanned between the first insulating portion and the second insulating portion. For this reason, in an insulating sheet, when bending, an excessive part does not exist and it is not necessary to bend an excessive part, Therefore It is easy to make an insulating sheet into a bottomed cylinder shape.

  Further, for the power storage device, the electrode assembly includes first end surfaces at both ends in the stacking direction, second end surfaces as both end surfaces in the width direction, and the corners, and the insulating sheet includes: The bottom insulating portion covering the bottom surface by being bent; the first insulating portion covering the pair of first end surfaces; and the second insulating portion covering the pair of second end surfaces; In a state where the insulating sheet is unfolded, the insulating sheet is formed by bending four corners of a rectangular bottom forming portion that is a precursor of the bottom insulating portion, and the bottom side Extending from a pair of first edge portions facing each other of the insulating portion, extending from a first sheet portion including the first insulating portion, and a pair of second edge portions orthogonal to the first edge portion, A second sheet part including two insulating parts, wherein the first sheet part includes the first sheet part; The second sheet portion includes a second extending portion that extends from the second insulating portion to the first chamfered portion, and includes a first extending portion that extends from an edge portion to the first chamfered portion. The insulating sheet bends each boundary line between the bottom insulating part and the first insulating part and each boundary line between the bottom insulating part and the second insulating part, and the first sheet part The extending portion is bent toward the first chamfered portion, the second extending portion of the second sheet portion is bent toward the first chamfered portion, and the first extending portion and the second chamfered portion are bent. The second chamfered portion may be formed by an extending portion, and an adhesive sheet may be bridged between the adjacent first extending portion and the second extending portion to form the bottomed cylinder.

  According to this, the insulating sheet in a state before being bent is composed of the bottom insulating portion, the first sheet portion, and the second sheet portion, and is composed of only the parts necessary for wrapping the electrode assembly. And the site | part which forms a 2nd chamfering part in the 1st sheet | seat part and the 2nd sheet | seat part was provided. For this reason, in an insulating sheet, when bending, an excessive part does not exist and it is not necessary to bend an excessive part, Therefore It is easy to make an insulating sheet into a bottomed cylinder shape.

In the power storage device, the insulating sheet may be formed by molding a heated sheet-like insulating sheet material.
According to this, the insulating sheet which has a chamfering shape can be manufactured easily.

  According to the present invention, it is possible to suppress interference between the corner portion of the case body and the insulating sheet when the electrode assembly is inserted into the case body.

The disassembled perspective view of the secondary battery of 1st Embodiment. The perspective view which shows the external appearance of a secondary battery. The disassembled perspective view which shows the component of an electrode assembly. (A) is a top view which shows the inside of a secondary battery, (b) is a top view which expands and shows a corner part vicinity. The top view which expand | deploys and shows an insulating sheet. (A) is a top view which expand | deploys and shows the insulating sheet of 2nd Embodiment, (b) is a perspective view which shows an insulating sheet. (A) is a top view which expand | deploys and shows the insulating sheet of 3rd Embodiment, (b) is a perspective view which shows an insulating sheet. (A) is a top view which expand | deploys and shows the insulating sheet of 4th Embodiment, (b) is a perspective view which shows an insulating sheet. (A) is a top view which expand | deploys and shows the insulating sheet of 5th Embodiment, (b) is a perspective view which shows an insulating sheet. (A) is a top view which expand | deploys and shows the insulating sheet of 6th Embodiment, (b) is a perspective view which shows an insulating sheet. The top view which expand | deploys and shows the insulating sheet of 7th Embodiment. The perspective view which shows the state which shape | molds an insulating sheet using a core.

Hereinafter, a first embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIGS.
As shown in FIGS. 1 and 2, a secondary battery 10 as a power storage device includes a case 11 in which an electrode assembly 12 is accommodated. The case 11 includes a rectangular parallelepiped case main body 13 and a rectangular flat cover 14 that closes the opening 13 a of the case main body 13. The case main body 13 and the lid body 14 constituting the case 11 are both made of metal (for example, stainless steel or aluminum).

  The case body 13 includes a rectangular flat bottom wall 13b, a long side wall 13c erected from a pair of long edges of the bottom wall 13b, and a short side wall 13d erected from a pair of short edges of the bottom wall 13b. And a corner portion 13e located at the intersection of the adjacent long side wall 13c and short side wall 13d. In a plan view of the case body 13 viewed from the opening 13a side, the inner surface of each corner portion 13e has an arc shape. The secondary battery 10 of the present embodiment is a prismatic battery whose appearance is square. Further, the secondary battery 10 of the present embodiment is a lithium ion battery.

  A positive electrode terminal 15 and a negative electrode terminal 16 for taking out electricity from the electrode assembly 12 are electrically connected to the electrode assembly 12. The positive electrode terminal 15 and the negative electrode terminal 16 are exposed to the outside of the case 11 through a pair of opening holes 14 a arranged in parallel with the lid body 14 at a predetermined interval. Further, a ring-shaped insulating ring 17 a for insulating from the case 11 is attached to the positive terminal 15 and the negative terminal 16, respectively.

  As shown in FIG. 3, the electrode assembly 12 includes a sheet-like positive electrode 20 and a sheet-like negative electrode 21. The positive electrode 20 has a positive electrode metal foil (in this embodiment, an aluminum foil) 22 and a positive electrode active material layer 23 formed by applying a positive electrode active material on both surfaces thereof. The negative electrode 21 has a negative electrode metal foil (copper foil in this embodiment) 24 and a negative electrode active material layer 25 formed by applying a negative electrode active material on both surfaces thereof. The electrode assembly 12 is a layered body having a separator 26 interposed between the positive electrode 20 and the negative electrode 21. The separator 26 is made of a microporous film. For example, as illustrated in FIG. 4B, the electrode assembly 12 is configured by alternately laminating a plurality of positive electrodes 20 and a plurality of negative electrodes 21. That is, the electrode assembly 12 is provided with a plurality of sets each including the positive electrode 20, the negative electrode 21, and the separator 26.

  The long side of the negative electrode 21 is longer than the long side of the positive electrode 20, and the short side of the negative electrode 21 is longer than the short side of the positive electrode 20. Further, the long side length of the separator 26 is longer than the long side length of the negative electrode 21, and the short side length of the separator 26 is longer than the short side length of the negative electrode 21. For this reason, the separator 26 is one size larger than the negative electrode 21.

  As shown in FIG. 3, a positive electrode tab 28 made of a positive electrode metal foil 22 is provided at the edge (one end) of the positive electrode 20 so as to protrude. The positive electrode tabs 28 are formed in the same position and in the same shape in each positive electrode 20 constituting the electrode assembly 12. Further, a negative electrode tab 30 made of a negative electrode metal foil 24 is provided at the edge (one end) of the negative electrode 21 so as to protrude. The negative electrode tab 30 is formed in the same position and in the same shape in each negative electrode 21 constituting the electrode assembly 12.

  Each positive electrode 20 is laminated such that the respective positive electrode tabs 28 are arranged in a line along the lamination direction of the electrode assembly 12. Similarly, each negative electrode 21 is laminated so that the respective negative electrode tabs 30 are arranged in a line along the lamination direction of the electrode assembly 12 so as not to overlap the positive electrode tab 28. As shown in FIG. 1, the positive electrode tabs 28 are collected in a range from one end to the other end in the stacking direction of the electrode assembly 12 to form a positive electrode tab group 31. The positive electrode terminal 15 is electrically joined to the positive electrode tab group 31. Similarly, as shown in FIG. 1, the negative electrode tabs 30 are gathered in a range from one end to the other end in the stacking direction of the electrode assembly 12 to form a negative electrode tab group 32. A negative electrode terminal 16 is electrically connected to the negative electrode tab group 32.

  As shown in FIG. 2, in this embodiment, the electrode assembly 12 is a rectangular parallelepiped having six surfaces. The six surfaces of the electrode assembly 12 are connected to the bottom surface 12a, the two first end surfaces 12b that are both end surfaces in the stacking direction of the electrode assembly 12, the bottom surface 12a and the first end surface 12b, and the electrode assembly 12 The first end surface 12b and the tab side end surface 12d connected to the second end surface 12c are perpendicular to the stacking direction. In addition, if the direction orthogonal to the stacking direction among the surface directions along the bottom surface 12 a is a width direction, the second end surface 12 c is both end surfaces of the electrode assembly 12 in the width direction. The tab side end face 12d is an end face from which the positive electrode tab 28 and the negative electrode tab 30 protrude. Further, the electrode assembly 12 includes four corners 12f. That is, the electrode assembly 12 includes corner portions 12f that are continuous with the four corners of the bottom surface 12a.

  As shown in FIG. 1, the secondary battery 10 includes an insulating sheet 33 that houses the electrode assembly 12. The insulating sheet 33 insulates the electrode assembly 12 from the metal case 11. The insulating sheet 33 is an insulating material, and is made of, for example, polyethylene (PE), polypropylene (PP), polyphenylene sulfide (PPS), or the like. The electrode assembly 12 accommodated in the insulating sheet 33 is inserted from the opening 13 a of the case body 13 and accommodated in the case 11. The thickness of the insulating sheet 33 is 50 to 300 μm.

  For example, when the insulating sheet 33 is made of polypropylene (PP), when the thickness of the insulating sheet 33 is 100 μm or more, the rigidity of the insulating sheet 33 is increased, and the insulating sheet 33 is deformed to match the shape of the electrode assembly 12. Is difficult to do. The insulating sheet 33 is made of polypropylene (PP) and has a flexural modulus equal to or higher than the flexural modulus obtained by the test method defined in JIS K7171, when the thickness is 100 μm. In consideration of the insertion property of the electrode assembly 12 wrapped with the insulating sheet 33 into the case main body 13, it is necessary to take measures for the shape of the bottom side of the insulating sheet 33. Hereinafter, countermeasures will be described together with the description of the insulating sheet 33.

  The insulating sheet 33 includes a bottom-side insulating portion 34 having a hexagonal shape in plan view. The bottom insulating part 34 is flat and is disposed between the bottom wall 13 b of the case body 13 and the bottom surface 12 a of the electrode assembly 12. In the present embodiment, the bottom insulating part 34 is disposed along the bottom surface 12 a of the electrode assembly 12. The bottom insulating portion 34 insulates the bottom wall 13b of the case body 13 from the bottom surface 12a of the electrode assembly 12.

  FIG. 5 shows the insulating sheet 33 in a developed state. FIG. 5 shows the insulating sheet 33 in an enlarged manner. As shown in FIG. 5 or FIG. 1, the bottom insulating portion 34 includes a pair of parallel first edge portions 34a and a pair of second edge portions 34b orthogonal to the first edge portion 34a and parallel to each other. The first chamfered portion 34c is provided at a position connecting the adjacent first edge portion 34a and the second edge portion 34b, and four first chamfered portions 34c are provided. The first edge 34 a of the bottom insulating part 34 is along the long side wall 13 c of the case body 13, and the second edge 34 b of the bottom side insulating part 34 is along the short side wall 13 d of the case body 13. Further, the first chamfered portion 34 c of the bottom side insulating portion 34 faces the inner surface of the corner portion 13 e of the case main body 13.

  As shown in FIG. 4A or 5, the length W <b> 1 of the bottom insulating portion 34 in the longitudinal direction is slightly longer than the length X of the electrode assembly 12 in the width direction. Note that the length W1 in the longitudinal direction of the bottom-side insulating portion 34 is a length between the pair of second edge portions 34b. Further, the length W2 of the bottom-side insulating portion 34 in the short direction is slightly longer than the length Z of the electrode assembly 12 in the stacking direction. Note that the length W2 of the bottom-side insulating portion 34 is the length between the pair of first edge portions 34a.

  As shown in FIG. 1, the insulating sheet 33 includes a first insulating part 35 protruding from each first edge 34 a of the bottom insulating part 34, a second insulating part 36 protruding from each second edge 34 b, It has the 2nd chamfering part 37 located between the 1st insulating part 35 and the 2nd insulating part 36 which adjoin. The second chamfered portion 37 is connected to the first insulating portion 35 and the second insulating portion 36 and has a shape in which the intersecting portion of the first insulating portion 35 and the second insulating portion 36 is chamfered. The second chamfered portion 37 is also connected to the first chamfered portion 34c. The first insulating portion 35 is disposed between the long side wall 13c of the case body 13 and the first end surface 12b of the electrode assembly 12, and insulates the long side wall 13c and the first end surface 12b. The second insulating portion 36 is disposed between the short side wall 13d of the case body 13 and the second end surface 12c of the electrode assembly 12, and insulates the short side wall 13d from the second end surface 12c. The second chamfered portion 37 is disposed between the corner portion 13e of the case body 13 and the corner portion 12f of the electrode assembly 12, and insulates the corner portion 13e and the corner portion 12f.

  In the insulating sheet 33, a direction in which the first insulating portion 35, the second insulating portion 36, and the second chamfered portion 37 are extended from the bottom-side insulating portion 34 is defined as an extending direction T. The extending direction T is a direction orthogonal to the inner surface of the bottom-side insulating portion 34 and coincides with the depth direction of the case main body 13.

  Since the second chamfered portion 37 extends over the entire extending direction T of the insulating sheet 33, the chamfered portion 38 of the insulating sheet 33 is configured by the first chamfered portion 34 c and the second chamfered portion 37. Yes. The chamfered portion 38 is provided over the entire extending direction T of the insulating sheet 33. The dimension of the chamfered portion 38 along the extending direction T is not less than the thickness of the bottom insulating portion 34 and is not less than 1 mm. Therefore, the portion of the insulating sheet 33 that faces the corner portion 13 e of the case body 13 has a chamfered shape from the outer bottom surface of the bottom-side insulating portion 34.

  As shown in FIG. 4A, in the insulating sheet 33, the direction in which the pair of first insulating portions 35 face each other is the stacking direction of the electrode assemblies 12. In the insulating sheet 33, the opening width along the stacking direction is the widest at the portion where the pair of first insulating portions 35 face each other. Further, the opening width of the insulating sheet 33 is gradually narrowed from the first insulating portion 35 toward the second insulating portion 36 at the portion where the second chamfered portion 37 is opposed. In a plan view of the electrode assembly 12 as viewed from the tab-side end surface 12d side, the second chamfered portion 37 is C-shaped.

  As shown in FIG. 4B, the electrode assembly 12 is shaped by the second chamfered portion 37 so that the dimension in the stacking direction is gradually shortened toward each second end surface 12c. However, on each second end face 12 c side of the electrode assembly 12, the positive electrode 20 has a size that is slightly smaller in outer shape than the negative electrode 21, and both longitudinal ends of the positive electrode 20 are both longitudinal ends of the negative electrode 21. It is located inside the part. For this reason, even if each 2nd end surface 12c side of the electrode assembly 12 is narrowed by the 2nd chamfering part 37, the part which protruded from the positive electrode 20 of the negative electrode 21 is only bent. For this reason, the state where the positive electrode active material layer 23 of the positive electrode 20 and the negative electrode active material layer 25 of the negative electrode 21 face each other is maintained.

  In the case 11, the entire chamfered portion 38 of the insulating sheet 33 faces the entire depth direction of the corner portion 13 e of the case body 13. A slight gap exists between the corner portion 13e and the chamfered portion 38 over the entire depth direction of the case body 13. Therefore, the first chamfered portion 34c and the second chamfered portion 37 do not interfere with the corner portion 13e.

Next, the insulating sheet 33 will be described in detail with reference to the developed state.
As shown in FIG. 5, the insulating sheet 33 has a rectangular sheet shape in a developed state. In the insulating sheet 33, each first edge 34a and the first insulating part 35 of the bottom-side insulating part 34 are continuous via the first boundary line L1 along the first edge 34a, and from the first edge 34a. A first insulating portion 35 is extended. Each first chamfered portion 34c and second chamfered portion 37 of the bottom-side insulating portion 34 are continuous via the second boundary line L2, and the second chamfered portion 37 extends from the first chamfered portion 34c. It is installed. Further, the first insulating portion 35 and the second chamfered portion 37 are continuous via the third boundary line L3.

  The insulating sheet 33 includes a overlapping portion 39 extending in a rectangular shape from the second edge portion 34 b of the bottom insulating portion 34, and a rectangular portion sandwiched between the overlapping portion 39 and the second chamfered portion 37. The surplus part 40 is provided. In the insulating sheet 33, the second chamfered portion 37 and the surplus portion 40 are continuous via the fourth boundary line L4, and the overlapping portion 39 and the surplus portion 40 are continuous via the fifth boundary line L5. Yes. In addition, each second edge 34b of the bottom insulating portion 34 and the overlapping portion 39 are continuous via the sixth boundary line L6. In the surplus portion 40, the dimension F along the longitudinal direction of the insulating sheet 33 is slightly shorter than the dimension in the stacking direction of the electrode assembly 12. The surplus portion 40 is a portion that forms part of the second insulating portion 36.

  The insulating sheet 33 has a bottomed box shape by being folded along the first to sixth boundary lines L1 to L6. The bending mode will be described in detail below together with the procedure for attaching the insulating sheet 33 to the electrode assembly 12 and the like.

  First, the insulating sheet 33 is attached to the electrode assembly 12 so as to be wrapped from the bottom surface 12 a side of the electrode assembly 12. Specifically, the insulating sheet 33 is attached so that the bottom-side insulating portion 34 and the bottom surface 12a of the electrode assembly 12 overlap. The insulating sheet 33 is first bent along each first boundary line L1. As a result, both first end surfaces 12 b in the stacking direction of the electrode assembly 12 are covered with the first insulating portions 35.

  Further, the insulating sheet 33 is bent along each second boundary line L2. That is, it is bent along each first chamfer 34c. Thereby, the corners 12 f of the electrode assembly 12 are covered with the second chamfered portions 37. Further, the insulating sheet 33 is bent along the fifth boundary line L5. Next, the insulating sheet 33 is bent along the third boundary line L3 and the fourth boundary line L4. Accordingly, the corner portion of the electrode assembly 12 is covered by the second chamfered portion 37, and part of the second end surface 12 c of the electrode assembly 12 is covered by part of the excess portion 40, so that the pair of excess portions 40 And the second end face 12c is covered, and the second insulating portion 36 is formed.

  In the state where the insulating sheet 33 is unfolded, a fold line J extending obliquely from the intersection P between the second boundary line L2 and the sixth boundary line L6 is set. The insulating sheet 33 is bent along the folding lines J and the fifth boundary line L5, whereby the overlapping portions 39 are folded into the second insulating portions 36 and overlap each other. The second insulating portion 36 is formed by folding the overlapping portion 39 and the surplus portion 40, but the overlapping portion 39 and the surplus portion 40 are within the dimensions of the second insulating portion 36 in the stacking direction. Yes.

Thereafter, the fixing tape 41 is attached so as to straddle the portion where the second insulating portion 36 and the overlapping portion 39 overlap each other and the second insulating portion 36.
Next, the operation of the secondary battery 10 will be described.

  The electrode assembly 12 wrapped in the insulating sheet 33 is inserted into the case main body 13 with the bottom side insulating portion 34 as the insertion destination side, whereby the electrode assembly 12 is accommodated in the case main body 13. At this time, the first chamfered portion 34 c prevents the insulating sheet 33 from interfering with the corner portion 13 e of the case main body 13. Then, the insulating sheet 33 restricts short-circuit between the surfaces 12 b to 12 c other than the tab-side end surface 12 d of the electrode assembly 12 and the case body 13.

According to the above embodiment, the following effects can be obtained.
(1-1) The insulating sheet 33 includes a first chamfered portion 34 c on the bottom-side insulating portion 34. For this reason, in the insulating sheet 33, the part facing the corner part 13e of the case main body 13 has a C-plane shape, and there is a gap between the corner part 13e. Therefore, when the electrode assembly 12 wrapped in the insulating sheet 33 is inserted into the case main body 13, it is possible to prevent the insulating sheet 33 from interfering with the corner portion 13 e of the case main body 13. Can be inserted smoothly. Therefore, in order to suppress interference between the case main body 13 and the insulating sheet 33, the entire insulating sheet 33 does not need to be downsized, and the electrode assembly 12 accommodated in the insulating sheet 33 does not need to be downsized. It is not necessary to reduce the battery capacity of the secondary battery 10.

  (1-2) The insulating sheet 33 is thick with rigidity. Therefore, when the electrode assembly 12 wrapped in the insulating sheet 33 is inserted into the case main body 13, if the insulating sheet 33 interferes with the corner portion 13 e, the insulating sheet 33 is hardly deformed and the insertion into the case main body 13 is hindered. It is done. Even in the secondary battery 10 using such an insulating sheet 33, by providing the first chamfered portion 34 c, it is possible to suppress the insulating sheet 33 from interfering with the corner portion 13 e of the case body 13. The solid body 12 can be smoothly inserted into the case body 13.

  (1-3) The insulating sheet 33 includes a second chamfered portion 37. For this reason, when the electrode assembly 12 is accommodated in the case main body 13, the second insulating portion 34 is accommodated in the case main body 13 without interference between the corner portion 13 e of the case main body 13 and the insulating sheet 33. The chamfered portion 37 allows the electrode assembly 12 to be inserted into the case body 13 while suppressing interference with the corner portion 13e. Therefore, the workability of the work of inserting the electrode assembly 12 into the case main body 13 is improved by both the first chamfered portion 34 c and the second chamfered portion 37.

  (1-4) The second chamfered portion 37 extends over the entire extending direction T of the insulating sheet 33. Therefore, the interference between the corner portion 13e and the insulating sheet 33 can be suppressed until the entire electrode assembly 12 is accommodated in the case body 13, and the workability of the work of inserting the electrode assembly 12 into the case body 13 is improved.

  (1-5) The bottomed cylindrical insulating sheet 33 is formed by bending the rectangular sheet-shaped insulating sheet 33 along the first to sixth boundary lines L1 to L6 and the folding line J. For this reason, since a clearance gap is not formed in the insulating sheet 33 which covers each surface 12a-12c of the electrode assembly 12, insulation is improved.

  (1-6) In the insulating sheet 33, the second insulating portion 36 is configured by overlapping the pair of surplus portions 40 and the overlapping portion 39. As a result, a gap that exposes the second end face 12 c of the electrode assembly 12 is unlikely to be formed in the second insulating portion 36.

  (1-7) Furthermore, a part of the pair of surplus portions 40 and the overlapping portion 39 are not protruded, and are within the dimension in the stacking direction of the electrode assembly 12. Thereby, when the electrode assembly 12 is accommodated in the case main body 13, the insulating sheet 33 is not easily disturbed.

  (1-8) In particular, if a part of the second insulating portion 36 protrudes to the pair of first insulating portions 35, the pair of first insulating portions 35 are formed with protruding portions that protrude from other portions. It is assumed that a local load is applied to the convex portion. Then, in the electrode assembly 12, a local load is applied to the opposing region of the positive electrode active material layer 23 and the negative electrode active material layer 25, and inconvenience such as lithium deposition may occur. On the other hand, according to this embodiment, since the surplus part 40 is bent so that it may be settled in the dimension to the lamination direction of the electrode assembly 12, the said problem is hard to generate | occur | produce.

(Second Embodiment)
Next, a second embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIG. In the second embodiment, detailed description of the same parts as those in the first embodiment is omitted.

  As shown in FIGS. 6A and 6B, the first chamfered portion 34c and the second chamfered portion 37 of the insulating sheet 33 have a curved shape in a rounded shape when viewed from above. In the state where the insulating sheet 33 is developed, the second boundary line L2 and the third boundary line L3 shown in the first embodiment are not formed. For this reason, the second chamfered portion 37 is not formed by valley folding with respect to the first chamfered portion 34c and the first insulating portion 35 of the bottom-side insulating portion 34, but along the fourth boundary line L4. When the boundary between the second chamfered portion 37 and the surplus portion 40 is bent, the second chamfered portion 37 is formed by bending according to the course.

Therefore, according to the second embodiment, in addition to the effects described in the first embodiment, the following effects can be obtained.
(2-1) The first chamfered portion 34c and the second chamfered portion 37 are curved so as to have a rounded shape in plan view. For this reason, when the electrode assembly 12 wrapped in the insulating sheet 33 is inserted into the case main body 13, it is possible to prevent the insulating sheet 33 from interfering with the corner portion 13 e of the case main body 13. It can be inserted smoothly. Therefore, in order to suppress interference between the case main body 13 and the insulating sheet 33, the entire insulating sheet 33 does not need to be downsized, and the electrode assembly 12 accommodated in the insulating sheet 33 does not need to be downsized. It is not necessary to reduce the battery capacity of the secondary battery 10.

  (2-2) The second chamfered portion 37 does not bend the insulating sheet 33 along the second boundary line L2 and the third boundary line L3, but when the second chamfered portion 37 and the surplus portion 40 are folded. It is formed by the course. For this reason, the operation | work which bends the insulating sheet 33 along the 2nd boundary line L2 and the 3rd boundary line L3 becomes unnecessary, and shaping | molding of the insulating sheet 33 is easy to perform.

(Third embodiment)
Next, a third embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIG. Note that in the third embodiment, detailed description of the same parts as those in the first embodiment is omitted.

  As shown in FIGS. 7A and 7B, in the state where the insulating sheet 33 is unfolded, a notch 42 is formed at a position along the fifth boundary line L5 shown in the first embodiment. ing. The notch 42 is provided at the boundary between the pair of surplus portions 40 and the overlapping portion 39. The notch 42 has a certain width in the short direction of the insulating sheet 33.

  And the insulating sheet 33 bends between each 1st boundary line L1 of the bottom side insulating part 34 and the 1st insulating part 35, and the bottom side insulating part 34 and the 2nd chamfering part 37, and is 1st insulation The portion 35, the second chamfered portion 37, and the surplus portion 40 are erected with respect to the bottom insulating portion 34.

  Next, the fourth boundary line L4 between the second chamfered portion 37 and the surplus portion 40 is bent using the notch 42 and the surplus portions 40 facing each other are overlapped, and the overlapping portion 39 and the bottom insulating portion 34 are overlapped. Each of the sixth boundary lines L6 is bent using the cuts 42 to form the second insulating portion 36, and the second insulating portion 36 and the overlapping portion 39 are overlapped. Thereafter, the fixing tape 41 is pasted so as to straddle the second insulating portion 36 and the overlapping portion 39.

Therefore, according to the third embodiment, the following effects can be obtained in addition to the effects described in the first embodiment.
(3-1) Since the cuts 42 are provided in the insulating sheet 33, it is easy to perform an operation of overlapping the surplus portion 40 and the overlapping portion 39.

(Fourth embodiment)
Next, a fourth embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIG. In the fourth embodiment, detailed description of the same parts as those in the first embodiment is omitted.

  As shown in FIGS. 8A and 8B, in a state where the insulating sheet 33 is unfolded, the insulating sheet 33 is a rectangular first insulating portion extending from each first edge portion 34a. 35, a second insulating portion 36 extending from each second edge portion 34b, and a second chamfered portion 37 extending from each first chamfered portion 34c. The adjacent first chamfered portion 35 and the second chamfered portion 37 are separated from each other, and the adjacent second chamfered portion 37 and the second insulating portion 36 are separated from each other.

  The insulating sheet 33 includes the first boundary lines L1 between the bottom insulating part 34 and the first insulating part 35, the sixth boundary lines L6 between the bottom insulating part 34 and the second insulating part 36, and the bottom side. Each of the second boundary lines L2 between the insulating portion 34 and the second chamfered portion 37, that is, the first chamfered portion 34c is bent. Further, in the insulating sheet 33, the adjacent first insulating portion 35 and the second chamfered portion 37 are bonded together by the rectangular adhesive sheet 43, and the adjacent second insulating portion 36 and the second chamfered portion 37 are The rectangular adhesive sheet 43 is attached.

Therefore, according to the fourth embodiment, the following effects can be obtained in addition to the effects described in the first embodiment.
(4-1) The insulating sheet 33 is composed of the bottom-side insulating portion 34, the first insulating portion 35, the second insulating portion 36, and the second chamfered portion 37, and wraps the electrode assembly 12. Consists of only the necessary parts. For this reason, in the insulating sheet 33, since there is no surplus part at the time of bending and it is not necessary to bend the surplus part, the insulating sheet 33 is easy to manufacture in a bottomed cylindrical shape.

(Fifth embodiment)
Next, a fifth embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIG. Note that in the fifth embodiment, detailed description of the same parts as those in the first embodiment is omitted.

  As shown in FIGS. 9A and 9B, in a state where the insulating sheet 33 is unfolded, the insulating sheet 33 is a rectangular first insulating portion extending from each first edge portion 34a. 35 and a second insulating portion 36 extending from each second edge portion 34b. The insulating sheet 33 bends each first boundary line L1 between the bottom-side insulating part 34 and the first insulating part 35 and each sixth boundary line L6 between the bottom-side insulating part 34 and the second insulating part 36 and is adjacent thereto. The adhesive sheet 43 is bridged between the first insulating part 35 and the second insulating part 36 to form a bottomed cylindrical shape, and the second chamfered part 37 is formed by the adhesive sheet 43. Note that the adhesive sheet 43 is an insulating sheet having adhesiveness, has an insulating property, and the adhesive sheet 43 constitutes a part of the insulating sheet 33. The first chamfered portion 34c of the bottom insulating portion 34 may have a C-plane shape in plan view or a round shape in plan view. The pressure-sensitive adhesive sheet 43 is adhered along the first chamfered portion 34c, and the second chamfered portion 37 has a C-plane shape in plan view or a round shape in plan view.

Therefore, according to the fifth embodiment, the following effects can be obtained in addition to the effects described in the first embodiment.
(5-1) In the insulating sheet 33, the second chamfered portion 37 is formed by the adhesive sheet 43 spanned between the first insulating portion 35 and the second insulating portion 36. For this reason, in the insulating sheet 33, since there is no surplus part when it bends and it is not necessary to bend the surplus part, it is easy to make the insulating sheet 33 into a bottomed cylindrical shape.

(Sixth embodiment)
Next, a sixth embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIG. In the sixth embodiment, detailed description of the same parts as those in the first embodiment is omitted.

  As shown in FIGS. 10A and 10B, in a state where the insulating sheet 33 is unfolded, the insulating sheet 33 has a rectangular bottom forming portion 341 that is a precursor of the bottom insulating portion 34. Prepare. Then, the first chamfered portion 34c is formed by cutting the four corners of the bottom forming portion 341 along the corner and bending along the cut, and the bottom-side insulating portion 34 is formed. The insulating sheet 33 extends from the bottom insulating portion 34 and the pair of first edge portions 34a of the bottom insulating portion 34, and includes the first sheet portion S1 including the first insulating portion 35 and the second edge portion 34b. The second sheet portion S <b> 2 that extends and includes the second insulating portion 36 is provided.

  The first sheet portion S1 includes a first extending portion Sa1 that extends from the first insulating portion 35 to the first chamfered portion 34c, and the second sheet portion S2 extends from the second insulating portion 36 to the first chamfered portion 34c. The second extending portion Sa2 is provided.

  And each 1st boundary line L1 of the bottom side insulation part 34 and the 1st insulation part 35 and each 6th boundary line L6 of the bottom side insulation part 34 and the 2nd insulation part 36 are bent, and bottom side insulation is carried out. The first sheet portion S1 and the second sheet portion S2 are erected with respect to the portion 34. Then, the 1st insulating part 35 is formed by a part of 1st sheet | seat part S1, and the 2nd insulating part 36 is formed by a part of 2nd sheet | seat part S2.

  Further, the first extending portion Sa1 of the first sheet portion S1 is bent toward the first chamfered portion 34c, and the second extended portion Sa2 of the second sheet portion S2 is bent toward the first chamfered portion 34c. . Then, the second chamfered portion 37 is formed by the first extending portion Sa1 and the second extending portion Sa2. The adhesive sheet 43 is bridged and fixed between the adjacent second chamfered portion 37 and the second insulating portion 36.

Therefore, according to the sixth embodiment, in addition to the effects described in the first embodiment, the following effects can be obtained.
(6-1) The insulating sheet 33 is composed of the bottom-side insulating portion 34, the first sheet portion S1, and the second sheet portion S2, and is composed only of parts necessary for wrapping the electrode assembly 12. And the site | part which forms the 2nd chamfering part 37 was provided in 1st sheet | seat part S1 and 2nd sheet | seat part S2. For this reason, in the insulating sheet 33, since there is no surplus part when it bends and it is not necessary to bend the surplus part, it is easy to make the insulating sheet 33 into a bottomed cylindrical shape.

(Seventh embodiment)
Next, a seventh embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIG. In the seventh embodiment, detailed description of the same parts as those in the first embodiment is omitted.

  As shown in FIG. 11, in a state where the insulating sheet 33 is unfolded, the insulating sheet 33 includes a first insulating portion 35 and a pair of first insulating portions 35 extending from a pair of first edge portions 34 a facing the bottom insulating portion 34. A second insulating portion 36 extending from the second edge portion 34b of the first insulating portion 35, and a surplus portion 40 including the second chamfered portion 37 and located between the adjacent first insulating portion 35 and the second insulating portion 36. Prepare. The insulating sheet 33 includes a cut 42 extending along the boundary between the first insulating portion 35 and the second insulating portion 36 and the surplus portion 40, and the surplus portion 40 extends from the first chamfered portion 34 c. . Each surplus portion 40 has a triangular shape between the second chamfered portion 37 and the first insulating portion 35 and between the second chamfered portion 37 and the second insulating portion 36.

  Then, the insulating sheet 33 bends each first boundary line L1 between the bottom-side insulating portion 34 and the first insulating portion 35 by using the cuts 42, and the first insulating portion 35 is erected with respect to the bottom-side insulating portion 34. Let Further, the sixth boundary lines L6 between the bottom-side insulating part 34 and the second insulating part 36 are bent using the notches 42, and the second insulating part 36 is erected with respect to the bottom-side insulating part 34.

  Next, each second boundary line L <b> 2 between the bottom-side insulating portion 34 and the surplus portion 40, that is, the first chamfered portion 34 c is bent using the cuts 42. In the surplus portion 40, the fold line J is formed on the first insulating portion 35 side and the second insulating portion 36 side from the portion where the second chamfered portion 37 is formed. The fold line J extends perpendicularly to the second boundary line L2 from both ends of each second boundary line L2.

  Then, among the portions protruding from the second chamfered portion 37 by bending the surplus portion 40 from each fold line J, the portion on the first insulating portion 35 side is overlapped with the second insulating portion 36 and the second chamfered portion 37, A portion on the second insulating portion 36 side is overlapped with the second insulating portion 36. Finally, the adjacent first insulating portion 35 and the second chamfered portion 37 are bonded together by a rectangular adhesive sheet 43, and the adjacent second insulating portion 36 and the second chamfered portion 37 are rectangularly shaped. The adhesive sheet 43 is attached.

Therefore, according to the seventh embodiment, in addition to the effects described in the first embodiment, the following effects can be obtained.
(7-1) In the insulating sheet 33, a cut 42 is formed at a position sandwiching the surplus portion 40, and the surplus portion 40 is bent into a bottomed cylindrical shape. For this reason, the insulating sheet 33 is not cut off, and the material yield does not deteriorate.

In addition, you may change this embodiment as follows.
In each embodiment, the insulating sheet 33 includes the second chamfered portion 37 over the entire extending direction T, but is not limited thereto. When the electrode assembly 12 wrapped in the insulating sheet 33 is inserted into the case main body 13, if the insulating sheet 33 can be prevented from interfering with the corner portion 13 e of the case main body 13, the second chamfered portion 37 extends in the extending direction T. It does not have to be in the whole.

For example, the second chamfered portion 37 may be formed in a dimension of 1 mm from the outer bottom surface of the bottom-side insulating portion 34 continuously to the first chamfered portion 34c.
The insulating sheet 33 may be obtained by integrally deforming the bottom insulating part 34, the first insulating part 35, the second insulating part 36, and the second chamfered part 37 by thermally deforming the insulating sheet material 51. In this case, as shown in FIG. 12, a core 50 having a shape along the bottom insulating portion 34, the first insulating portion 35, the second insulating portion 36, and the second chamfered portion 37 is prepared, and the insulating sheet material 51 is prepared. Then, the insulating sheet material 51 is pressed against the core 50 to plastically deform the insulating sheet material 51 to form the insulating sheet 33. The method of plastically deforming the insulating sheet material 51 may be performed by vacuum forming, pressure forming, or press forming.

  In the expanded state, the rectangular insulating sheet 33 is bent along the core 50, and the portion that becomes the second chamfered portion 37 is heated by ultrasonic waves or induction heating, and in a softened state, the insulating sheet material 51 To form the second chamfered portion 37.

In the case 11, the bottom-side insulating portion 34 of the insulating sheet 33 that encloses the electrode assembly 12 may not be along the bottom wall 13 b of the case body 13 and may be separated from the bottom wall 13 b.
The power storage device can also be applied to power storage devices other than secondary batteries, such as capacitors.

The positive electrode 20 and the negative electrode 21 may have a structure in which an active material layer is present on one side of a metal foil.
The secondary battery 10 may be a lithium ion secondary battery or another secondary battery. In short, any ion may be used as long as ions move between the active material for the positive electrode and the active material for the negative electrode and charge is transferred.

  T ... extending direction, S1 ... first sheet portion, S2 ... second sheet portion, Sa1 ... first extending portion, Sa2 ... second extending portion, 11 ... case, 12 ... electrode assembly, 12a ... bottom surface, 12b ... first end face, 12c ... second end face, 12f ... corner, 13 ... case body, 13a ... opening, 13b ... bottom wall, 13e ... corner part, 14 ... lid, 20 ... positive electrode, 21 ... negative electrode Electrode, 33 ... insulating sheet, 34 ... bottom insulating part, 34a ... first edge, 34b ... second edge, 34c ... first chamfering part, 35 ... first insulating part, 36 ... second insulating part, 37: second chamfered portion, 39: overlapping portion, 40 ... surplus portion, 42 ... notch, 43 ... adhesive sheet, 50 ... core, 51 ... insulating sheet material, 341 ... bottom forming portion.

Claims (10)

An electrode assembly in which a plurality of positive electrodes and negative electrodes are alternately stacked in an insulated state;
A rectangular box-like case main body that accommodates the electrode assembly, and a case having a lid that closes an opening of the case main body;
A power storage device comprising a bottomed cylindrical insulating sheet that insulates the electrode assembly from the case,
The electrode assembly has a rectangular bottom surface and corners that are continuous with the four corners of the bottom surface, and in the electrode assembly, a direction in which the positive electrode and the negative electrode overlap is a stacking direction, and Of the surface directions along the bottom surface, the direction orthogonal to the stacking direction is the width direction,
The insulating sheet includes a flat bottom-side insulating portion disposed between a bottom wall of the case body and a bottom surface of the electrode assembly, and both end surfaces in the stacking direction of the electrode assembly and the case body. A first insulating portion disposed in the width direction, a second insulating portion disposed between the both end faces in the width direction and the case body,
A first chamfered portion provided on the bottom insulating portion and facing a corner portion of the case body;
A first chamfered portion connected to the first insulating portion and the second insulating portion;
The first chamfered portion is a power storage device connected to the second chamfered portion.   2. The power storage device according to claim 1, wherein a dimension of the entire chamfered portion including the first chamfered portion and the second chamfered portion is equal to or greater than a thickness of the bottom insulating portion.   The power storage device according to claim 2, wherein the bottom-side insulating portion includes an outer bottom surface that abuts on the bottom wall of the case body, and the dimension of the chamfered portion from the outer bottom surface is 1 mm. The electrode assembly includes a first end face as both end faces in the stacking direction, a second end face as both end faces in the width direction, and the corners.
The insulating sheet is bent so that the bottom insulating portion covering the bottom surface, the first insulating portion covering the pair of first end surfaces, and the second insulating portion covering the pair of second end surfaces, The second chamfered portion covering the corner portion, and the overlapping portion that covers a part of the bottom end side of the second end surface overlapping the second insulating portion,
In the state in which the insulating sheet is deployed, the insulating sheet is a pair of the first insulating portion extended from a pair of first edge portions of the bottom insulating portion facing each other, and a pair orthogonal to the first edge portion. The overlapping portion extending from the second edge of the second chamfered portion, the second chamfered portion extending from the first chamfered portion, and the adjacent second chamfered portion and the overlapping portion, A surplus part including the second insulating part;
The insulating sheet includes boundary lines between the bottom insulating portion and the first insulating portion,
The first chamfered portion located between the bottom-side insulating portion and the second chamfered portion;
And bending along each boundary line between the overlapped portion and the surplus portion,
Bending each boundary line between the second chamfered portion and the surplus portion and folding the surplus portions facing each other, folding each boundary line between the overlapping portion and the bottom insulating portion to form the second insulating portion The power storage device according to any one of claims 1 to 3, wherein the bottomed cylindrical shape is formed by overlapping the overlapping portion and the overlapping portion. The electrode assembly includes a first end face as both end faces in the stacking direction, a second end face as both end faces in the width direction, and the corners.
The insulating sheet is bent so that the bottom insulating portion covering the bottom surface, the first insulating portion covering the pair of first end surfaces, and the second insulating portion covering the pair of second end surfaces, The second chamfered portion covering the corner portion, and the overlapping portion that covers a part of the bottom end side of the second end surface overlapping the second insulating portion,
In the state in which the insulating sheet is deployed, the insulating sheet is a pair of the first insulating portion extended from a pair of first edge portions of the bottom insulating portion facing each other, and a pair orthogonal to the first edge portion. The overlapping portion extending from the second edge of the first chamfered portion, the second chamfering portion extending from the first chamfered portion, and the adjacent second chamfered portion and the overlapping portion. A surplus part including the second insulating part, and further comprising a notch at the boundary between the pair of surplus parts and the overlapping part,
The insulating sheet includes boundary lines between the bottom insulating portion and the first insulating portion,
Each boundary line between the surplus part and the second chamfered part,
And bend each boundary line between the bottom insulating portion and the overlapping portion,
Each boundary line between the overlap portion and the bottom insulating portion is folded while folding the surplus portions facing each other by folding each boundary line between the second chamfered portion and the surplus portion. The power storage device according to any one of claims 1 to 3, wherein the bottomed cylindrical shape is formed by folding the second insulating portion and the overlapping portion by bending using a notch. The electrode assembly includes a first end face as both end faces in the stacking direction, a second end face as both end faces in the width direction, and the corners.
The insulating sheet is bent so that the bottom insulating portion covering the bottom surface, the first insulating portion covering the pair of first end surfaces, and the second insulating portion covering the pair of second end surfaces, And the second chamfered portion covering the corner,
In the state in which the insulating sheet is deployed, the insulating sheet is a pair of the first insulating portion extended from a pair of first edge portions of the bottom insulating portion facing each other, and a pair orthogonal to the first edge portion. The second insulating portion extended from the second edge of the second, and a second chamfered portion extended from the first chamfered portion,
The insulating sheet includes boundary lines between the bottom insulating portion and the first insulating portion,
Each boundary line between the bottom insulating portion and the second insulating portion,
And bent along the first chamfered portion located between the bottom-side insulating portion and the second chamfered portion, the adjacent first insulating portion and the second chamfered portion, and the adjacent second chamfered portion. The power storage device according to any one of claims 1 to 3, wherein the bottomed cylindrical shape is formed by bonding the chamfered portion and the second insulating portion with an adhesive sheet. The electrode assembly includes a first end face as both end faces in the stacking direction, a second end face as both end faces in the width direction, and the corners.
The insulating sheet is bent so that a bottom-side insulating portion that covers the bottom surface, a first insulating portion that covers the pair of first end surfaces, a second insulating portion that covers the pair of second end surfaces, and the corners The second chamfering part covering the part,
In the state in which the insulating sheet is deployed, the insulating sheet is a pair of the first insulating portion extended from a pair of first edge portions of the bottom insulating portion facing each other, and a pair orthogonal to the first edge portion. The second insulating part extending from the second edge of the first insulating part, the surplus part including the second chamfered part, located between the adjacent first insulating part and the second insulating part, and the first A slit extending along a boundary between the insulating portion and the second insulating portion and the surplus portion;
The insulating sheet includes boundary lines between the bottom insulating portion and the first insulating portion,
Each boundary line between the bottom insulating portion and the second insulating portion,
In addition, each boundary line between the bottom insulating portion and the surplus portion is bent using the notch, and a portion other than the second chamfered portion in the surplus portion is overlaid on the second insulating portion. The adjacent first insulating portion and the second chamfered portion, and the adjacent second chamfered portion and the second insulating portion are bonded together with an adhesive sheet to form the bottomed cylindrical shape. The power storage device according to claim 3. The electrode assembly includes a first end face as both end faces in the stacking direction, a second end face as both end faces in the width direction, and the corners.
The insulating sheet is bent so that the bottom insulating portion covering the bottom surface, the first insulating portion covering the pair of first end surfaces, and the second insulating portion covering the pair of second end surfaces, Including,
In a state where the insulating sheet is deployed, the insulating sheet is orthogonal to the first insulating portion extending from a pair of first edge portions facing each other of the bottom insulating portion, and the first edge portion. A second insulating portion extending from a pair of second edges;
The insulating sheet includes boundary lines between the bottom insulating portion and the first insulating portion,
And bending each boundary line between the bottom insulating portion and the second insulating portion, and bridging an adhesive sheet between the adjacent first insulating portion and the second insulating portion to form the bottomed cylindrical shape, The power storage device according to any one of claims 1 to 3, wherein the second chamfered portion is formed by a sheet. The electrode assembly includes first end faces at both ends in the stacking direction, second end faces as both end faces in the width direction, and the corners,
The insulating sheet is bent so that the bottom insulating portion covering the bottom surface, the first insulating portion covering the pair of first end surfaces, and the second insulating portion covering the pair of second end surfaces, Including,
In the state in which the insulating sheet is unfolded, the insulating sheet is formed by bending the four corners of a rectangular bottom forming portion that is a precursor of the bottom insulating portion, and the bottom insulating portion. Extending from a pair of first edge portions facing each other of the side insulating portion, extending from a first sheet portion including the first insulating portion, and a pair of second edge portions orthogonal to the first edge portion, A second sheet portion including a second insulating portion;
The first sheet portion includes a first extending portion that extends from the first insulating portion to the first chamfered portion, and the second sheet portion extends from the second insulating portion to the first chamfered portion. With a second extending part,
The insulating sheet includes boundary lines between the bottom insulating portion and the first insulating portion,
And bending each boundary line between the bottom insulating portion and the second insulating portion,
Bending the first extending portion of the first sheet portion toward the first chamfered portion and bending the second extending portion of the second sheet portion toward the first chamfered portion;
The second chamfered portion is formed by the first extended portion and the second extended portion, and an adhesive sheet is bridged between the adjacent first extended portion and the second extended portion, and the bottomed portion is formed. The power storage device according to any one of claims 1 to 3, wherein the power storage device is cylindrical.   The power storage device according to any one of claims 1 to 3, wherein the insulating sheet is formed by molding a heated sheet-like insulating sheet material.