TWI310252B - Improved battery pack - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a battery pack having an improved structure, and more particularly to a battery pack in which ultrasonic welding is applied to sidewalls extending from the upper and lower outer casings. Each of the side walls has a predetermined thickness, and a film-like label is formed on the upper surface and/or the lower surface of the outer casing, whereby although the thickness is very small, the coupling force is very large due to ultrasonic welding. The structural stability of the drop or external impact is high, and the junction area of the coupling area is large, and as a result, it is not necessary to attach any label for increasing the coupling force and preventing the insertion of foreign matter. [Prior Art]

When mobile devices have made great progress, and the demand for such mobile devices has increased significantly, there is a strong demand for secondary batteries as power sources for mobile devices. One of the secondary batteries is a lithium secondary battery having a high energy density and a discharge voltage, which has been extensively studied and is now in large use on the market. Lithium secondary batteries are generally classified into a cylindrical shape, a rectangular shape, or a pouch shape based on their appearance. Lithium secondary batteries are generally classified into lithium ion batteries or lithium polymer batteries based on their electrolytes. As mobile devices become smaller and smaller, the demand for rectangular and pouch-shaped batteries having relatively low thicknesses is increasing. Furthermore, based on how the secondary battery is placed in the casing, the battery pack is usually classified into a hard battery pack or an inner battery pack. A typical example of a hard battery pack is exemplified in the first figure. Referring to the first figure, the rigid battery pack 10 forms part of the outer portion 1210, and the hard battery pack 10 is placed thereon. Thus, the advantages of the rigid battery pack 10 are that the rigid battery pack can be easily placed on the external component 12 when in use. However, it is necessary to design the outer casing U (shell) according to various external components, and a unit battery (not shown) is disposed on the outer casing 12. Thus, the manufacturing cost of the hard battery pack 10 is still 'and the compatibility of the hard battery pack 10 with the external components is low.

On the other hand, as shown in the second figure, the inner battery pack 20 is placed in an external component and then covered with a cover which forms part of the outer component. Thus, although it is relatively troublesome to load the inner battery pack 20 into an external component, the inner battery pack 2 has the advantages that the inner battery pack is easy to design, the inner battery pack is low in manufacturing cost, and the inner battery pack is compatible with external components. High sex. For details of the internal battery pack containing rectangular unit batteries, please refer to the third and fourth figures. Referring to the drawings, the inner battery pack includes: a one-type unit battery 21 having an anode terminal formed on one side thereof and a cathode terminal formed on the other side thereof; and a temperature connected to one of the two electrode terminals of the unit battery 21. Coefficient (PTC) section 22 to preliminarily protect the battery from overcurrent discharge and overcharge; connected to the PTC element 22 side electrode terminal via the -nickel plate 23, and connected to the other electrode terminal via the other rider 27 (anode terminal) A protection circuit unit 24 has an external output on the outside of the town side: the unit 24 is connected to the corresponding external component (not shown = yuan 24. Peripheral position ^21, PTC component protection circuit There is an insulating sheet 28 between the unit cell 2_彳 edge and the nickel plate 23 and between the protection circuit unit 1310252 24 and the nickel plate 27, which avoids the difference between the nickel plate 23 and the unit cell 21 or the nickel plate 27 and the protection circuit unit. There is also a short circuit of 24 unnecessary contacts. Also, the double-sided tape 29 is located between the unit cell 21 and the lower casing 26, so that the unit cell 21 can be firmly attached to the bottom of the lower casing 26 by the double-sided tape 29. Thus, when Unit battery 21 is placed on top In the case of the case 25 and the lower case 26, the unit cell 21 can be stably located in the upper case 25 and the lower case 26. After the upper case 25 is coupled to the lower case 26, the unit cell β 21 is housed therein, and the upper case 25 is The lower outer casing 26 can be covered by the packaging label 30, which further increases the coupling force between the upper outer casing 25 and the lower outer casing 26, and prevents foreign matter from being inserted into the coupling region between the upper outer casing and the lower outer casing, or inserted into the upper outer casing and the lower outer casing. The fifth figure is a schematic diagram illustrating an inner battery pack including a conventional unit battery of a pouch type, the sixth diagram is a fifth diagram, the explosion diagram of the battery pack, and the seventh diagram is shown in the fifth figure, the battery section Schematic diagram of the combination.

Referring to the drawings, the battery pack 50 includes a pouch-type unit battery 51 having an electrode assembly, which is composed of an anode, a cathode, and a separator, and is disposed therein together with an electrolyte in a sealed state, and has an inner space. The outer casing 52 accommodates the unit battery 51, and an upper casing 53 coupled to the lower casing 52, in which a unit battery 51 is housed to seal the unit battery 51. Further, the double-sided tape 54 is located between the unit cell 51 and the upper and lower casings 53 and 52, so that the unit cells 51 can be stably located in the inner space defined by the casings 53 and 52. After the upper casing 53 is coupled to the lower casing 52, the unit cells 13l2S2aj are accommodated therein, and the coupled upper and lower casings 25 and 26 are covered by the package label 40, as in the battery pack 2G in _2 to 4 The assembly method increases the coupling force of the upper and lower outer casings 53 and 52 1 and prevents foreign matter from being inserted into the coupling area between the upper and lower outer casings or into the upper and lower outer casings. In the battery pack 20 of the first figure and the battery pack 50 of the fifth figure, the upper and lower peripherals are made of a glue material such as a polyether (PC) or an acrylonitrile butadiene styrene copolymer (ABS). ), the upper and lower casings are firmly _ _ in the ultrasonic welding. Ultrasonic welding is a kind of detail that uses high-frequency vibration, day, for example, 20,000 Hz friction heat to join the two surfaces together. The details of the upper and lower casings are coupled by ultrasonic welding. , test the eighth to eleventh. The eighth diagram is a sub-surface view illustrating the upper casing 53 disposed on the lower casing 52, and the ninth view is a vertical plan view of the coupled upper and lower casings 52" 53 (a section along the eighth line AA) When the upper casing 52 is on, the opposite ends of the upper casing 53 are in contact with the opposite ends of the lower casing 1. The tenth figure is a portion of the contact portion B exemplified in the ninth figure, in the part of ^, a The eleventh figure is an exemplification of the ninth figure - the touch point B, the partial enlarged view after the ultrasonic welding. As the tenth figure, the wedge ten welding ridge 61 is formed at the end of the upper casing 53, The soldering surface is formed at the end of the upper casing 52 such that the soldering surface 71 is in contact with the wedge-shaped soldering ridge. When high-frequency vibration is applied to the wedge-shaped soldering ridge 61 and the splicing surface 71, _烊(4)q and the soldering surface Ή It is shown that the η, 疋' wedge-shaped solder ridges 61 and the soldering surface 71 are bonded to each other. 8 1310252 /, ', and the demand for a small battery pack having a lower thickness is more than a year. The thickness of 52 and upper casing 53 has been reduced to 〇.3 more than 5 mm. As a result, it is difficult to report the mold through the molding method or the injection mold method, and the upper and outer sides, and again, when the size of the welding and the welding surface 71 is reduced, the welding strength is reduced, thus increasing the defect. Welding rate. Also, if the upper case having a small thickness and the lower case having a small thickness are welded to each other via the super-f 2 connection, the hybrid between the lower case and the upper case is "not too large. The shape of the packaging label wraps the surface of the battery pack to ensure that the battery pack must be combined and prevented from being inserted into the upper and lower outer casings, or into the upper and lower outer casings. One reason is that it requires a battery pack that is resistant to external impact strength and can be easily manufactured at a low manufacturing cost even if a low-thickness outer casing is used. [Summary of the Invention] For the purpose of solving the previous (four) questions, and others have not yet been solved ^ The inventor of the present invention solves the above-mentioned internal and external research and experimentation. The inventor of the present application extends the thickness of the private casing from the upper casing and the W (four) 3, and the wall of each wall Having a predetermined surface, whereby =3 is formed on the upper surface of the outer casing and/or the lower surface is very large, and the structural stability against the impact of the external shock is high. And the junction area of the 1310252 domain of the light junction area is large Therefore, it is not necessary to attach any label for increasing the coupling force and preventing the insertion of foreign matter. The present invention has been completed based on the foregoing findings. According to the present invention, the foregoing and other objects are achieved by providing a battery pack including a rectangular unit cell of an electrode assembly, which is composed of a plurality of anodes, a plurality of cathodes, and a plurality of separators, is disposed therein together with an electrolyte in a sealed state; a lower casing having an inner space for accommodating a unit battery; and a lower casing Coupling an upper casing, wherein the unit battery is housed to seal the unit battery, wherein the upper and lower casings have a plurality of side walls each having a predetermined thickness, whereby the coupling regions of the upper and lower casings are located in units a plurality of sides of the battery, and a film-like label formed on at least one surface selected from an upper surface of the upper outer casing and a lower surface of the lower outer casing. According to the present invention, ensuring sufficient implementation on the upper and lower outer casings It is possible to have an appropriate thickness of one of the ultrasonic welding without increasing the thickness of the battery pack. As a result, the coupling force and the coupling region are enhanced. The junction area of the domain. Therefore, it is not necessary to attach any label for increasing the coupling force and preventing the insertion of foreign matter, and therefore, the manufacturing process of the battery pack is simplified. The outer casing of the upper plate and the lower result of the outer casing, the outer casing is limited to In the conventional battery pack, as shown in the second to seventh figures, the lower casing is coupled to the lower casing, and the upper portion thereof is open, so that the coupling region of the coupling region of the casing is located at a corresponding portion of the corner of the unit cell is limited to the outer casing of the low thickness. The end is to ensure a correct thickness. In another aspect, according to the present invention, the side walls are individually formed on the upper and lower outer casings, and the side walls of the upper and lower outer casings are coupled to each other. Thus, the coupling area between the outer casings is in units. On the side of the battery, the thickness of the wall of the battery pack does not increase the thickness of the battery pack to the thickness suitable for ultrasonic welding because of the I-Ma 10 1010252 between the outer casings; The predetermined thickness means that it is suitable for super-tone restrictions. Furthermore, the predetermined thickness increases the strength; ^^ thickness, and does not specifically θ θ the boundary area of the light δ region, both = necessary. Any packaging label used to prevent the foreign matter #Α^ is better implemented. The side material of the outer casing is approximately equivalent to: 1:=: the length and thickness of the wall, thereby constructing the upper and lower outer casings. A roughly symmetrical structure. Thus, the area of the face between the upper and lower casings is approximately at the center of the side of the unit cell, thus ensuring a thickness that is most suitable for ultrasonic welding. In another preferred embodiment, the battery pack includes a step portion in which the upper surface and the side walls of the outer casing meet each other, = a portion that is slightly curved into a curved shape. This is slightly (four) curved, and the impact on the external force applied to the upper corner is opposite. The structure in which the skin is slightly curved into a curve is also applied in the same manner. The field of the upper casing and the lower casing is not particularly limited, that is, the ultrasonic wave is implemented _ The part, consisting of __ two „ polycarbon (four) (called, decene nitrile butyl ethylene such as, for example, the overall external a, ^ things (eight 38). Wind, including sidewalls, can be composited by plastic materials bismuth metal Made of material. The leaf contains plastic and when the battery pack is dropped or impacted by external force, the external force is combined with the lower outer casing, so the upper and outer sides. = the outer or outer coupling region 11 1310252 = face only =::: Acts on the upper surface of the battery pack or the upper surface of the battery pack (on the upper side of the battery pack: the lower surface of the battery pack = the lower side of the battery pack, = force action =: used in the battery pack) A large. On the 3, the upper surface or the battery _ the following table _ the opportunity is relatively unprotected = even if the traditional battery pack shown in the second to seventh figure, this does not protect the battery pack against the external force vertical Face and lower surface. In the examination of this (four) ❹ w recognize, and the above table plus the animal · ^ The demand for the battery pack with 溥 continues to increase = it is better to manufacture the upper surface of the upper casing with a relatively low thickness and the lower surface 1 of the outer casing and the lower surface 1 of the outer casing, and in consideration of the limit of the injection mold, The welding ridge formed during welding has a specific limitation on the conventional battery pack, and on the other hand, 'the ultrasonic wave welding is applied to the side wall extending from the top 2 according to the present invention, thereby solving the prior art In addition, according to the present invention, considering the problem of the prior art in the prior art, that is, the limit of the injection mold, the lightning, the ice, the battery, and the structure are formed, and the film-shaped label is formed on the upper and outer (four). The structure of the surface. The area formed by the label may be part or all of the upper surface of the upper outer casing, or the label may be formed on the lower outer casing. Otherwise, the label may be separately formed on the upper surface and the lower outer casing of the upper outer casing. The lower surface of the battery pack can be formed in a variety of ways on the upper surface or surface of the battery pack. 彳 to adhere the film-like label to the upper surface of the upper outer casing frame (and/or The outer casing is built The open upper surface (4) of the upper outer casing frame or the open inner surface of the lower outer casing frame is formed on the lower surface of the lower outer casing frame. Alternatively, the film-like label can be inserted into a mold and passed through the injection mold method. The outer casing frame (and/or the lower casing frame) is formed. According to the present invention, the insert injection mold method is preferably used to form the label. The material of the film label is not particularly limited. For example, the label may be made of a plastic material, such as poly. Carbonate (PC), polyethylidene ester (PET) or a thin film metal material. Best, the label is made of plastic material. Considering the thickness of the battery pack and the function of the label as a protective element, the label The ideal thickness is about 0.1 to 0.2 mm, but the thickness of the label is not limited by the aforementioned dimensions. However, considering the fact that the thickness limit of the film injection mold method is about 0.2 mm, it is to be noted that the present invention enables inclusion The battery pack of the outer casing has a very thin upper surface and a very thin lower surface which cannot be produced by a film injection molding process. A rectangular or pouch type unit battery can be placed in the battery pack in accordance with the present invention based on its appearance. Preferably, the unit battery may be a lithium ion secondary battery or a lithium ion polymer secondary battery.

[Embodiment] The present invention will be exemplified in more detail by the following preferred examples and accompanying drawings. However, it is to be understood that the scope of the invention is not limited to the illustrated examples. Figure 12 is a schematic view showing the explosion of a battery pack according to a preferred embodiment of the assembled battery pack according to the present invention, and Figure 13 is a schematic view showing a battery after assembly of the battery pack according to the present invention. A schematic diagram of the combination of the groups. 13 1310252, please refer to this figure, the battery pack 100 includes a unit electric unit having an electrode assembly, which is composed of an anode, a cathode and a separator, and is disposed therein together with an electrolyte in a sealed state, and the lower casing 300 is disposed in a sealed state. The accommodating unit battery 200 is slidably coupled to the lower casing 300. The upper casing 4 is sealed to seal the unit battery 200°. The upper end of the unit battery 2GG is provided with a protection current device such as a protective electric quotation π module (PCM) 210. With a positive temperature coefficient (pcT) component. The lower casing 300 has an inner surface corresponding to the outer surface of the unit cell 2 such that the unit cell 200 can be positioned on the lower casing 3''. A terminal window 312 and a call are formed at the upper end of the lower casing 3'', thereby exposing the external input and the round-out terminals 212 and 214 of the PQvmO. The lower outer casing 300 and the upper outer casing 400 are generally constructed in a similar structure. Specifically, the film-shaped label 500 is formed on the lower surface of the lower casing 3 and the upper surface of the upper casing 4, and the side walls 32 and 420 are formed in the corresponding regions of the lower casing 3 and the upper casing 4''. Further, the shoulder 33 〇, the lower surface and the side wall 32 〇 meet each other, and the % is slightly curved into a curved partial shape. Similarly, the upper surface and the side wall 420, the meeting shoulder 430, are slightly curved into a curved partial shape. Therefore, the lower outer casing 300 and the upper outer casing 400 form an arch symmetrical structure, so that the lower outer casing 300 and the upper outer casing 4 are structurally stable when an external force is applied to the lower outer casing 3 and the upper outer casing 400. Fig. 14 is a view schematically showing the separation of the label from the outer casing of the battery pack shown in Fig. 13. Referring to Fig. 14, the upper casing 400 includes a frame 440 whose upper surface is completely opened. The label 500 is attached to the open upper surface of the upper casing 400. As previously mentioned, the 14 1310252 tag 500 can be formed on the open upper surface 442 of the upper housing in a variety of ways. For example, 'the label 500 is inserted into a predetermined mold (not shown), the inside of which is engraved into the same structure as the outer casing 400, and the molten resin is injected into the mold, whereby the indicator 500 is integrated and fixed by inserting the injection mold. The outer casing 4〇〇. Fig. 15 is a plan view showing a battery pack according to a preferred embodiment of the present invention, wherein a sixteenth view is a sectional view of the battery pack, and a seventeenth view is a partially enlarged view of the battery pack. Referring to the fifteenth diagram, the battery pack 100 is generally constructed to have a rectangular structure, so that the iron 500 is formed on the upper surface of the battery pack 1 . Referring to Fig. 16, the side wall 320 of the lower casing 3 and the side wall 42 of the upper casing 400 have a larger thickness and boundary surface than the conventional battery pack. The unit battery, the side walls 320 and 420, and the label 500 formed on the upper and lower surfaces of the battery pack are protected. Thus, the thickness of the battery pack 1 is substantially equal to the thickness of the unit cell 200, so that the battery pack 1 is made into a structure having a very low thickness. Referring to Fig. 17, in the ultrasonic welding of the battery pack according to the present invention, the side wall interface of the battery pack changes. A first step is formed at the upper end of the lower casing side wall 32〇. A weld surface 322 is formed at the inner upper end of the lower casing side wall 32''. On the other hand, the lower end of the upper casing side wall 42 is constructed to correspond to the upper end step of the lower casing side wall 320. A welded ridge 422 is formed at the inner lower end of the upper casing side wall 42A. In the ultrasonic welding of the battery pack, the change occurs as in the tenth and tenth-graphs. In another example, a soldering surface can be formed at the upper end of the lower housing sidewall 320, and a solder ridge can be formed at the lower end of the upper housing sidewall 420. 15 1310252 A battery pack according to the present invention is preferably used for an inner battery pack. Having described the preferred embodiments of the present invention as illustrative, it is to be understood that various modifications, additions and substitutions may be made without departing from the scope and spirit of the invention. [Industrial Applicability] It is clear from the foregoing description that the battery pack according to the present invention can be made with a small thickness. Also, since the coupling force of ultrasonic welding is very large, the structural stability of β against drop or external force impact is high, and the junction area of the coupling region is large. Therefore, it is not necessary to attach any label for increasing the coupling force and preventing the insertion of foreign matter. [Simple description of the map]

The above and other objects, features and other advantages of the present invention will become more <RTIgt; The first figure is a perspective view illustrating a rigid battery pack. The second figure is a perspective view illustrating a conventional inner battery pack including a rectangular unit battery. The third figure is an exploded perspective view of the battery pack in the second figure. The fourth figure is a perspective view of a partial combination of the battery packs in the second figure. The fifth figure is a perspective view illustrating a conventional inner battery pack including a pouch type unit battery. The sixth figure is an exploded perspective view of the battery pack shown in the fifth figure. The seventh figure is a perspective view of a partially assembled battery pack as shown in the fifth figure. 16 1310252 The eighth figure is a plan view illustrating a conventional battery pack. The ninth drawing is a cross-sectional view along line A-A of the eighth figure. The tenth picture is a partial enlarged view of part B of the ninth figure before ultrasonic welding. The eleventh picture is part B of the ninth figure, and the enlarged part of the image after ultrasonic welding. Fig. 12 is a perspective exploded view showing a battery pack in accordance with a preferred embodiment of the present invention.

Figure 13 is a perspective view showing the assembly of a battery pack in accordance with the preferred embodiment of the present invention. Figure 14 is a perspective view showing the separation of a label from the outer casing of the battery pack in accordance with the preferred embodiment of the present invention. Figure 15 is a plan view showing a battery pack in accordance with a preferred embodiment of the present invention. Figure 16 is a cross-sectional view along line C-C of the fifteenth figure.

Fig. 17 is a partially enlarged view showing a portion D of the sixteenth diagram. . [Description of main component symbols] Battery pack 10, 50, 100 External component 12 Housing 11 Internal battery pack 20 Positive temperature coefficient component 22 Nickel plate 23, 27 17 1310252

Protection circuit unit 24 upper casing 25, 53, 400 lower casing 26, 52, 300 insulating sheet 28 double-sided tape 29, 54 label 30, 40, 500 unit battery 21, 51, 200 protection current module 210 terminal window 312, 314 Input and output terminals 212, 214 sidewalls 320, 420 soldering surface 322 shoulders 330, 430 solder ridges 422 frame 440 upper surface 442

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Claims (1)

1310252 ;k : I l-\ mouth, 八r, patent range 1. A battery pack comprising: a rectangular unit cell having an electrode assembly, which is composed of a plurality of anodes, a plurality of cathodes and a plurality of separators, a sealed casing is disposed therein together with an electrolyte; a lower casing having an inner space for accommodating the unit battery; and an upper casing coupled to the lower casing, wherein the unit battery is housed to seal the unit battery , among them The upper and lower outer casings have a plurality of side walls each having a predetermined thickness, whereby the plurality of coupling regions of the upper and lower outer casings are located on the side edges of the unit battery, and a film-like label is formed on at least one surface It is selected from the upper surface of the upper outer casing and the lower surface of the lower outer casing. 2. The battery pack of claim 1, wherein the side walls of the upper outer casing have a length and a thickness corresponding to the side walls of the lower outer casing, whereby the upper outer casing and the lower outer casing are constructed to be substantially symmetrical. Structure. 3. The battery pack of claim 1, further comprising: a plurality of shoulders, wherein the upper surface of the upper outer casing and the side walls meet each other, the shoulders being slightly curved into a curved partial shape. 4. The battery pack of claim 1, further comprising: a plurality of shoulders, wherein the lower surface of the lower outer casing and the side walls meet each other, the shoulders being slightly curved into a curved partial shape. 5. The battery pack of claim 1, wherein the side wall regions of the upper and lower outer casings, that is, portions for performing ultrasonic welding, are made of a plastic material such as polycarbonate (PC) or acrylonitrile. Butadiene-styrene copolymer 19 1310252 (ABS). The battery pack of claim 1, wherein the area formed by the label may be the upper surface of the upper outer surface or a portion or all of the lower surface of the lower outer casing. U month asks for the battery pack of the member 1, inserts the label into the predetermined mold to = the upper outer casing or the lower outer casing, and uses an insert injection mold method to form an upper outer casing frame or a lower outer casing frame. 8 A battery pack according to claim 1 such as poly(5) carbonate (PC (ABS). wherein the label is made of a plastic material, or a thick ion of acrylonitrile-butadiene-styrene copolymer mm. = Battery pack of claim 1 wherein the label has 0.1 to 10. The request item is a battery cell or a lithium battery/early battery is a lithium ion polymer secondary battery. 20