JPH03127462A - Flat type organic electrolyte cell - Google Patents

Abstract

PURPOSE:To keep internal resistance low as well as to reduce scatter in said resistance by interposing a metallic positive electrode ring in a L-shape provided with a specified surface roughness between a positive electrode and a cell case in such a way that the bottom surface of it comes in contact with the cell case. CONSTITUTION:The bottom surface 6a of the brim section of a positive electrode ring 6 which comes in contact with a cell case 1, is roughened to meet the value equal to or more than the maximum roughness RMAX 10mum accordingly represented by JISB0601 while the opening tip end section of the case 1 concurrently acting as a positive electrode terminal is squeezed inward so that the periphery of a sealing plate 2 concurrently acting as a negative electrode terminal is squeezed via a gasket 4. By this constitution, internal resistance can thereby be kept low while scatter in said resistance is also reduced throughout storage from right after manufacture.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application The present invention relates to improvements in flat organic electrolyte batteries.

BACKGROUND OF THE INVENTION Conventional flat organic electrolyte batteries have generally been constructed in the form shown in Japanese Utility Model Publication No. 56-34374, as shown in FIG.

That is, the negative electrode 3 is crimped onto the sealing plate 2 into which the gasket 4 having a cross-sectional shape is inserted in advance, and the separator 5 is inserted into the shape of a bump along the inner surface of the gasket 4 to be fixed inside the sealing plate 2. . Then, insert the electrolyte, the pellet-shaped positive electrode 8, and the metal positive electrode ring 6 into the pot-shaped separator 5, place the battery case l on the outside of the gasket 4, and bend the tip of the case inward to stand it all up. Ta. Incidentally, a conductive adhesive 7 was applied to a portion of the collar of the metal positive electrode ring 6 that came into contact with the pellet-shaped positive electrode.

Problems to be Solved by the Invention When a flat organic electrolyte battery starts to react, the positive electrode 8
expands, and the negative electrode 3 decreases. Therefore, the expansion direction of the positive electrode is restricted in the vertical direction by the positive electrode ring to ensure contact inside the battery. According to the conventional configuration, the positive electrode does not come into direct contact with the battery case, but rather through the positive electrode ring, and the contact surfaces such as the contact between the positive electrode and the positive electrode ring, and the contact between the positive electrode ring and the battery case, There were many surfaces, which caused the problem of high contact resistance. In addition, both the positive electrode ring and the battery case were made of stainless steel with excellent corrosion resistance 11 and the bottoms were punched out, and the electrical connection between the positive electrode ring and the battery case was unstable. The electrolyte easily penetrates into the interface between the positive electrode ring and the battery case in a layered manner.
In that case, the electrical connection became particularly unstable, and significant variations in internal resistance of the battery occurred.

In order to stabilize the contact resistance, as shown in FIG. 3, a metal confectionery electric body 9 is welded to the center of the battery case 1 to stabilize the electrical contact between the pellet-shaped positive electrode 8 and the battery case l. has also been practiced previously. However, according to this method, although it is possible to stabilize the internal resistance of the battery immediately after manufacture, there is a problem that the manufacturing cost of the battery increases.

Furthermore, when a battery is stored at high temperatures, the organic electrolyte may decompose and generate gas, in which case the battery case 1 expands and the metal current collector 9 arranged in the center of the battery case 1 becomes pellet-shaped. There were cases where the particles were detached from the positive electrode 8 and the internal resistance of the battery increased.

The present invention solves the conventional problems and provides a low-cost internal resistance of a battery that is stable from immediately after manufacture to after storage. The purpose is to give.

In order to solve the problem more than the means for solving the problem, the present invention has an abbreviated cross section and a JISB060 standard on the bottom of the flange that is in contact with the battery case.
A metal positive electrode ring whose surface has been roughened to a maximum roughness of RlXloμm or more according to No. 1 is disposed between the pellet-shaped positive electrode and the battery case. Also, JIS B○601f:l:ii is applied to the contact surface of the battery case with the metal positive electrode ring.
! The surface is roughened to a maximum roughness of Rmax 10 tt m or more in terms of t;

Further, the contact surfaces of the metal positive electrode ring and the battery case are roughened to a maximum roughness of R111 x 10 μm or more, both of which are expressed in accordance with JISB0601.

Effect: According to the above configuration, at least one of the metal positive electrode ring and the battery case is roughened at the contact surface between the two parts, and a reliable electrical connection can be obtained. Further, even if the electrolytic solution permeates between the metal positive electrode ring and the battery case, the electrolytic solution does not form a layer between the positive electrode ring and the battery case and prevent the electrical connection between the two parts. Therefore, it is possible to stabilize the internal resistance of the battery.

Further, according to the present invention as described above, the metal positive electrode ring is located relatively on the outer periphery of the battery case, and when the battery is stored at a high temperature, the organic electrolyte decomposes and generates gas. Even if the battery expands, a stable internal resistance of the battery can be obtained.

EXAMPLES The present invention will be explained below using examples. FIG. 1A is a longitudinal cross-sectional view of a lithium-manganese dioxide type flat organic electrolyte battery with an outer diameter of 20 cm and a total height of 2.5 mlN used in the test. In the figure, l is a battery case that doubles as a positive electrode terminal, which is made by punching a stainless steel plate using a press, and 2 is a sealing plate that also serves as a negative electrode terminal, which is made by punching the same material, and lithium 3, which is a negative electrode active material, is crimped onto the inner wall. . 4 is a gasket made of polypropylene, 5 is a separator made of polypropylene nonwoven fabric impregnated with an organic electrolyte, and 6
a is a part where the bottom surface of the brim of the positive electrode ring 6, that is, the contact surface with the battery case, is roughened to a maximum roughness R□%10 μn1 or more, and the opening tip of the battery case 1, which also serves as the positive electrode terminal, is turned inward. Hermetically sealing is achieved by caulking and tightening the periphery of the sealing plate 2, which also serves as a negative electrode terminal, via the gasket 4.

In addition, FIG. 1B shows a battery case 1 in which the surface 1a in contact with the metal positive electrode ring 6 is roughened to a maximum roughness R1x10 μm or more, and the bottom surface of the flange portion is not roughened (the maximum roughness of the bottom surface is R
, ax 5 μm or less) is a cross-sectional view of a flat 8M electrolyte configured similarly to the battery shown in FIG. 1A using a metal positive electrode ring 6.

Furthermore, FIG. 1C shows both components in which the bottom surface 6a of the brim portion of the metal cathode ring 6 and the contact surface 1a between the cathode ring of the battery case 1 have been roughened to a maximum roughness of Rmaxi○μm or more. FIG. 2 is a cross-sectional view of a flat organic electrolyte battery constructed similarly to FIG. 1A using the same method.

The flat organic electrolyte batteries shown in FIGS. 1A, 1B, and 1C are α, β, and γ, respectively, and the conventional and L7 are shown in The internal resistance of each battery was measured immediately after manufacture and after storage at 60°C for 40 days. The average value and standard deviation of the internal resistance are shown in Table 1. n-100. In this example, the batteries α and γ of the present invention were constructed using a metal positive electrode J-ring whose bottom surface of the collar was roughened to a maximum roughness Rmax of 17 μm. Batteries β and γ were constructed using a battery case in which the surface in contact with the metal positive electrode ring was roughened to a maximum roughness RIIlax of 15 μm.The bottom surface of the metal positive electrode ring or ,
The maximum roughness of the battery case is Rmax 10 μm.
It has been confirmed through experiments that the same effect as in this example can be obtained by applying the above method.

Table 1 As is clear from Table 1, the maximum roughness R
In a flat organic electrolyte battery whose surface is roughened to 810 μm or more, it is possible to provide a flat organic electrolyte battery that has low internal resistance from immediately after manufacture to after storage and has small variations.

Effects of the Invention As is clear from the above description, according to the present invention, it is possible to obtain a flat organic electrolyte battery that has low internal resistance and small variations immediately after manufacture and after storage.

[Brief explanation of the drawing]

FIGS. 1A, B, and C are longitudinal sectional views of a flat organic electrolyte battery according to the present invention, and FIGS. 2 and 3 are longitudinal sectional views of a flat organic electrolyte battery having a conventional configuration. DESCRIPTION OF SYMBOLS 1...Battery case, 1a...Rough surface part of battery case, 2...Sealing plate, 3...Lithium, 4...Gasket , 5...Separator, 6...Metal positive electrode ring, 6a...
・・・・R1 surface of the brim part (rough surface part) of the metal positive electrode ring,
7... Conductive adhesive, 8... Bullet-shaped positive electrode, 9... Metal current collector.

Claims (3)

[Claims] (1) A negative electrode using a light metal as an active material, a positive electrode formed into a pellet, a separator and an organic electrolyte interposed between these positive and negative electrodes, a battery case that also serves as a positive terminal, a sealing plate that also serves as a negative terminal, and a battery case. and a battery sealed with a gasket interposed between the sealing plates, the cross section being approximately L-shaped, and the surface roughness of the bottom surface of the flange being a maximum roughness R_m_a as indicated in accordance with JISB0601.
A flat organic electrolyte battery in which a metal positive electrode ring having a diameter of _x10 μm or more is arranged such that its inner surface is inscribed in a pellet-like positive electrode and the bottom surface of the collar is inscribed in a battery case. (2) A negative electrode containing a light metal as an active material, a positive electrode formed into a pellet shape, a separator and an organic electrolyte interposed between these positive and negative electrodes, a battery case that also serves as a positive terminal, a sealing plate that also serves as a negative terminal, and a battery case. The battery is sealed by a gasket interposed between the positive electrode and the battery case, and a metal positive electrode ring having a substantially L-shaped cross section is disposed between the positive electrode and the battery case so as to be inscribed in the positive electrode and the battery case. The surface roughness of the surface in contact with the metal positive electrode ring of the case is JISB060.
A flat organic electrolyte battery having a maximum roughness R_m_a_x of 10 μm or more as indicated in accordance with 1. (3) A negative electrode using a light metal as an active material, a positive electrode formed into a pellet shape, a separator and an organic electrolyte interposed between these positive and negative electrodes, a battery case that also serves as a positive terminal, a sealing plate that also serves as a negative terminal, and a battery case. and a battery sealed with a gasket interposed between sealing plates, wherein a metal positive electrode ring having a substantially L-shaped cross section is disposed between the positive electrode and the battery case so as to be inscribed in the positive electrode and the battery case, and the battery case and the surface roughness of the contact surface of the metal positive electrode ring are both JISB0.
Maximum roughness R_m_a_x10μm according to 601
The above flat organic electrolyte battery.