JPH0265066A - Flat type nonaqueous liquid active material battery - Google Patents

Abstract

PURPOSE:To improve the adhesion between a positive electrode and a positive electrode current collector, increase the current collecting capability, and prevent the positive electrode from being removed from the positive electrode current collector by providing projections on the contact face side of the main current collecting section of the positive electrode current collector with the positive electrode. CONSTITUTION:Since projections 10d are provided on the main current collecting section 10a of a positive electrode current collector 10, the projections 10d bite into a positive electrode 2 when the positive electrode 2 is pressed to them, the adhesion between the positive electrode 2 and the positive electrode current collector 10 is improved, and the contact area is increased. The current collecting capability of the positive electrode current collector 10 is increased, the adhesion between the positive electrode 2 and the positive electrode current collector 10 is improved by the projections 10d, thereby the positive electrode 2 is made hard to be removed from the positive electrode current collector 10. The peripheral section 10b of the positive electrode current collector 10 blocks the movement of the positive electrode 2 in the lateral direction (radial direction), thus the positive electrode 2 can be prevented from being removed from the positive electrode current collector 10 due to vibration or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flat nonaqueous liquid active material battery using an oxyhalide liquid as a positive electrode active material.

[Conventional technology]

In recent years, with the development of electronic devices, lithium batteries with low self-discharge and long life have come into widespread use. Therefore, as a memory backup power source for CMOS RAM, a cylindrical lithium battery was developed that uses an oxyhalide liquid such as thionyl chloride as the positive electrode active material and a so-called hermetic seal of metal-glass-metal for the battery lid. (For example, JP-A-59-5145
8), the demand for these products is rapidly increasing because they have a high airtightness and can be used for a long period of time (10 years or more).

However, in the market, in addition to the above-mentioned cylindrical bank-up batteries, there are also smaller and thinner memory backup amplifier batteries due to the need to reduce the current consumption of ICs, or to make devices smaller and lighter. It has been demanded.

In order to meet such demands, highly airtight flat batteries have been developed that use oxyhalide-based liquids as positive electrode active materials and employ hermetic seals.

[Problems to be Solved by the Invention] However, in the above battery, as shown in FIG. 6, a molded body mainly made of a positive electrode active material such as manganese dioxide is used as the positive electrode current collector (10). A plain-woven wire mesh, similar to that used in flat lithium batteries, is used, and a positive electrode (2) made of a porous carbon material is crimped onto this to collect current. Because it is a body,
The adhesion between the positive electrode (2) and the positive electrode current collector 0[I] is weak, and the positive electrode (
2) detaches from the positive electrode current collector (10), resulting in a decrease in current collection ability or a short circuit.

In addition, since the positive electrode current collector (10) is composed of a flat wire mesh, it takes time and effort to align the positive electrode (2) and the positive electrode current collector (10). ) and the positive electrode (2) may be misaligned.

[Means to solve the problem]

Therefore, as shown in Figure 5, a metal plate is formed into a cap shape with the center part protruding toward the inside of the battery (lower side in Figure 5(b)), and this is shaped like the battery shown in Figure 4. Positive is electric body (
10), but in the case of using the positive electrode current collector (10), the positioning of the positive electrode (2) is facilitated by the peripheral wall (job) and the central protrusion (10c), and Although it has become rare for the positive electrode (2) and the positive electrode current collector (10) to completely separate due to vibration, etc., the positive electrode (
2) Since the lower surface of the main current collecting part (10a) that contacts the upper surface is flat, there is a problem that a sufficient current collecting effect cannot be obtained.

Therefore, in the present invention, as shown in FIGS. 1 to 3, by providing a protrusion (10d) on the contact surface side with the positive electrode (2) of the main current collecting part (10a) of the positive current collector 0ω, This improves the adhesion between the positive electrode (2) and the positive electrode current collector 0, thereby increasing the current collecting ability and preventing the positive electrode (2) from separating from the positive electrode current collector 0.

[Effect]

Protrusion (10d) on main current collector flOa) of positive electrode current collector 0ω
is provided, so when the positive electrode (2) is crimped onto this, the protrusion (10d) bites into the positive electrode (2), increasing the adhesion between the positive electrode (2) and the positive electrode current collector (10), and Since the contact area of the positive electrode current collector (10) also increases, the current collecting ability of the positive electrode current collector (10) increases.

In addition, the positive electrode (2) and the positive electrode current collector (
10), the positive electrode (2) becomes difficult to separate from the positive electrode current collector 0■. Furthermore, a positive electrode current collector (
The peripheral wall portion (10b) of the positive electrode (10) prevents the positive electrode (2) from moving in the lateral direction (radial direction).
) is less likely to separate from the positive electrode current collector 0■.

Also, the positive electrode (2)! When crimping to the electric body (10), the peripheral wall part (job) and the protruding part (10c) serve as guides, so it is easy to align the positive electrode (2) and the positive electrode current collector θ0, and the positive electrode (2) and the positive electrode current collector (10) are not misaligned.

[Example] Next, an example of the present invention will be described based on the drawings. However, although a lithium-thionyl chloride-based flat non-aqueous liquid active material battery will be described in the Examples, the present invention is not limited thereto.

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of a flat non-aqueous liquid active material battery of the present invention, and FIG. 2 shows a positive electrode current collector used in the battery shown in FIG. FIG. 2(a) is a plan view thereof, and FIG. 2(b) is an XX-line cross-sectional view of FIG. 2(a). However, in the cross-sectional views, outline lines of portions located on the back side of the cross-section, which may make the drawings complicated if shown, are omitted.

First, to roughly explain the structure of the battery, (1)
is a negative electrode made of lithium, (2) is a positive electrode made of an annular carbon porous molded body, and (3) is a separator made of glass fiber nonwoven fabric, which separates the negative electrode (1) and positive i (2). There is. (4) is an electrolyte, (5) is a battery container made of stainless steel, and (6) is a battery lid. It consists of an insulating layer (8) and a positive electrode terminal (9) made of stainless steel, and the outer periphery of the body (7) is welded to the open end of the battery container (5). (10) is a positive electrode current collector. CI+) is an insulator made of glass fiber non-woven fabric, which includes the positive electrode (2) and the positive electrode current collector (0 ports) and the battery lid (
6) and the body (7). 0 is the electrolyte injection port, and this electrolyte injection port θ is the battery container (5
), but the one in this example has a cylindrical shape with the tip located inside the battery (the electrolyte inlet O9 has a cylindrical shape). (means that the cylinder forms a gap through which the electrolyte can pass when the electrolyte is injected), and a sealing stopper made of a polytetrafluoroethylene ball is press-fitted after the electrolyte is injected.60 The sealing plate is made of stainless steel, and its central part covers the proximal opening of the electrolyte inlet θ, and its outer periphery is welded to the bottom (5a) of the battery container (5). .

This battery has an outer diameter of 33fi111 and a total height of 6.
．． It is a flat battery in the shape of a 5mm disc.

Next, the main constituent members will be explained in detail. The negative electrode (1) is constructed by pressing a lithium sheet punched into a ring shape to the bottom inner surface of the battery container (5). The positive electrode (2) is a porous molded body made of a carbonaceous material whose main component is acetylene black, to which graphite for strength and polytetrafluoroethylene as a binder are added. It is made of a so-called carbon porous molded body, with a porosity of about 85% by volume and an outer diameter of 27.
1. It is formed into an annular body with an inner diameter of 3nv and a thickness of 3.5mm. Electrolyte solution (4) consists of 1. lithium aluminum tetrachloride in thionyl chloride. Omol/l? It consists of a solution of thionyl chloride, and thionyl chloride is both an electrolyte solvent and a positive electrode active material as described above. As is clear from the fact that thionyl chloride is used as the positive electrode active material, the positive electrode (2) itself does not react with thionyl chloride, which is the positive electrode active material, and the negative electrode (1).
) provides a site for reaction with lithium ions ionized from ).

The battery container (5) is made of a stainless steel plate with a thickness of 0.51 mm and is shaped like a container with an outer diameter of 3 m and a height of 6 lll, and in the center of the bottom (5a) there is a hole with an inner diameter of 2.11 mm on the inside of the battery. Cylindrical electrolyte injection port with a height of approximately 1.5 mm with a tip 0
2) is provided.

As mentioned above, the battery cover (6) has a stainless steel body (
7), an annular insulating layer (8) made of glass, and a positive electrode terminal (9) made of stainless steel, and the insulating layer (8) made of glass has a stainless steel body (
7), and the inner peripheral surface is welded to the outer peripheral surface of the positive electrode terminal (9) made of stainless steel, and has a so-called metal-glass-metal hermetically sealed seal. As shown in the figure, the body (7) of the battery M (6) is welded to the open end of the battery container (5), and the battery is configured to have a so-called completely sealed structure.

The positive electrode current collector 0ω is formed from a stainless steel plate with a thickness of O and 1 mm, and includes an annular main current collector part (10a) that contacts the upper surface of the positive electrode (2) and the main current collector part (10a).
) is located at the outer peripheral end of the main current collecting part f10a) and has its tip on the inside of the battery, and a projecting part (10c) is located on the inner peripheral side of the main current collecting part f10a) and projects toward the inside of the battery. The main current collector (10a) is provided with three annular protrusions (10d) on the side of the contact surface with the positive electrode (2).

The upper surface of the convex portion t10c of the positive current collector 0[I] is joined to the lower surface of the positive terminal (9) of the battery lid (6) by welding, and the main current collecting portion of the positive current collector Oω is (10a) is crimped with an annular positive electrode (2), and the main current collector (10a) is connected to the positive electrode (2).
), but when the positive electrode (2) is crimped to the main current collecting part (10a), the peripheral wall part (10b) and the protruding part (Inc) act as a guide, so the positive electrode (2) and the main current collecting part (108) of the positive electrode current collector 0ω are easily aligned, and no misalignment occurs between the two.

In addition, the positive electrode (2) is connected to the main current collecting part (1) of the positive current collector (10).
0a), the protrusion (10d) provided on the main current collector part [10a) bites into the positive electrode (2), so that the positive electrode [
2] and the positive electrode current collector (0 port) increases, and the contact area between the two increases, the current collection ability of the positive electrode current collector θω improves, and the battery is prevented from being subjected to vibrations or Even when the battery is dropped, the positive electrode (2) is unlikely to separate from the positive electrode current collector aω. In addition, the surrounding wall part (10
b) also collects current by contacting the outer peripheral surface of the positive electrode (2), and prevents the positive electrode (2) from moving in the lateral direction when the battery is subjected to vibrations. ) is less likely to separate from the positive electrode current collector 0Ω.

Fig. 3 shows another example of the positive electrode current collector used in the battery of the present invention, Fig. 3(a) is a plan view thereof, Fig. 3(b)
is a sectional view taken along the line Y-Y in FIG. 3(a).

The positive electrode current collector 0 (D is a protrusion (10d) shown in FIG.
) is formed in a conical shape with a hole at the tip, and this protrusion +1
A large number of protrusions flOd) are provided such that a discontinuous ring is formed at 0d).

However, as shown in Fig. 2, it is easier to press the protrusion [10d) if the protrusion [10d] is circular in cross-sectional shape, and it is also easier to provide a plurality of such annular protrusions. This is preferable because it is easy to increase the area of the protrusion (10d) and the current collecting action can be performed uniformly.

The battery of the embodiment of the present invention shown in FIG. 1 and the battery shown in FIG. 4 (that is, the main current collector (10a>
FIG. 7 shows the discharge characteristics of a battery using a positive electrode current collector (0 ports) with a flat bottom surface, which was continuously discharged at 20°C11 Ω.

In FIG. 7, the discharge characteristics of the battery according to the example of the present invention are shown by curve A, and the discharge characteristics of the battery shown in FIG. 4 are shown by curve B. The discharge characteristics of the battery are flat, and the discharge voltage is high when viewed at the same discharge time. On the other hand, as shown by curve B, the battery shown in FIG. 4 showed a significant voltage drop during discharge, and flat discharge characteristics could not be obtained. This is the positive electrode current collector (10
) is caused by the fact that the contact surface of the main current collector [10a) with the positive electrode (2) is flat, so that reliable contact between the positive electrode (2) and the positive electrode current collector (10) cannot be obtained. it is conceivable that.

In the above example, the insulating layer (8) was made of glass, but the insulating layer (8) may be made of ceramic instead of glass.Also, in the example, lithium was used for the negative electrode and the positive electrode Lithium using thionyl chloride as active material
Although the thionyl chloride battery has been explained, the negative electrode may be composed of an alkali metal other than lithium such as sodium or potassium, and the positive electrode active material may also be composed of sulfuryl chloride, phosphoryl chloride, etc. other than thionyl chloride at room temperature (25'C). It may be a liquid oxyhalide.Furthermore, in the example, a porous molded body containing acetylene black as the main component was used for the positive electrode (2), but a porous molded body containing mainly carbonaceous material other than acetylene black may be used. It may also be used as a component.

〔Effect of the invention〕

As explained above, the present invention has the positive electrode current collector 0ω having the above configuration, thereby ensuring contact with the positive electrode (2) to enhance the current collecting effect, and improving alignment with the positive electrode (2). Moreover, it was possible to reduce the possibility of the positive electrode (2) and the current collector (10) coming apart due to vibration or falling.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of a flat non-aqueous liquid active material battery of the present invention. Figure 2 shows the positive electrode current collector used in the battery shown in Figure 1. Figure 2 (a) is its top view, and Figure 2 (b) is the XX line of Figure 2 (a). FIG. FIG. 3 shows another example of the positive electrode current collector used in the flat non-aqueous liquid active material battery of the present invention.
3 is a plan view thereof, and FIG. 3(a) is a sectional view taken along the line Y--Y in FIG. 3(a). FIG. 4 is a longitudinal sectional view showing a flat non-aqueous liquid active material battery other than the present invention. Fig. 5 shows the positive electrode current collector used in the battery shown in Fig. 4, Fig. 5(a) is its plan view, Fig. 5(0)) It is a Z line sectional view. FIG. 6 is a longitudinal sectional view showing another example of a flat non-aqueous liquid active material battery other than the present invention. FIG. 7 is a discharge characteristic diagram of the battery according to the embodiment of the present invention shown in FIG. 1 and the battery other than the present invention shown in FIG. (1)...Negative electrode, (2)...Positive electrode, (3)...
・Separator, (4)... Electrolyte, (5)... Battery container, (6)... Battery lid, (7)... Body,
(8)...Insulating layer, (9)...Kingdom terminal, 0ω
... Positive electrode current collector, (10a) ... Main current collector, +j
ob)...Peripheral wall part, (Inc)...Protruding part, (
10d)... Protrusion 10 - iE electrode current collector Oa main collector part +01), peripheral wall part 10c, protruding part 10d, protrusion No. 4, negative electrode positive electrode cenogrator' electrolyte 8. Battery container'; Ii battery lid body 6, Figure 8...Insulating layer 9, IE extreme) lO positive electrode current collector 10a, main collector 101)...peripheral wall 10c, protrusion 10d protrusion negative electrode 1] Mopole/Separator Electrolyte 'City/I! ! Container 6・'City seal 7・・Body 8・Insulation 9・Positive electrode terminal 10・Positive electrode current collector (h)

Claims (2)

[Claims] (1) Use an alkali metal such as lithium, sodium, or potassium for the negative electrode (1), use a cyclic carbon porous molded body for the positive electrode (2), and use oxygen such as thionyl chloride, sulfuryl chloride, or phosphoryl chloride as the positive electrode active material. Using a halide-based liquid, the power generation element containing the negative electrode (1), positive electrode (2), and positive electrode active material is placed between the battery container (5) and the battery lid (6).
The battery lid (6) is a metal annular body (7), and the battery lid (6) is made of glass or ceramics and is located on the inner circumferential side of the annular body (7). an annular insulating layer (8) consisting of the annular insulating layer (8);
The outer periphery of the body (7) of the battery lid (6) is located at the center of the battery container (8).
5), and the positive electrode current collector (10) is in contact with the upper surface of the positive electrode (2).
, a peripheral wall portion (10b) located at the outer peripheral end of the main current collecting portion (10a) and having a tip portion on the inside of the battery;
0a) is located on the inner circumferential side and protrudes toward the inside of the battery (
10c), the upper surface of the protrusion (10c) is joined to the lower surface of the positive electrode terminal (9), and the main current collector (10a) is connected to the lower surface of the positive electrode terminal (9).
) is provided with a protrusion (10d) on the side of the contact surface with the positive electrode (2). (2) The flat non-aqueous liquid active material battery according to claim 1, wherein the protrusion (10d) is an annular protrusion.