JP2005209560A - Negative electrode can and button type battery using negative electrode can - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a button type battery of which a negative electrode can is covered and in which liquid leakage is prevented. <P>SOLUTION: Anti-liquid leakage property of a flat-type alkaline battery is improved significantly by forming coatings principally consisting of a thiadiazole derivative on copper or copper alloy surface of a negative electrode can. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a negative electrode can used for a button type battery and a button type battery using the negative electrode can. In particular, it covers the negative electrode can to prevent leakage.

A flat type silver oxide battery using zinc as a negative electrode, a caustic electrolyte as an electrolyte, and silver (I) oxide as a positive electrode, for example, inserts a gasket serving as a positive electrode and negative electrode insulation into a positive electrode can, a positive electrode mixture, a separator, The impregnating agent and the negative electrode mixture are sequentially placed, and after pouring the caustic electrolyte from the upper part, the negative electrode can is united, the opening edge of the positive electrode can is caulked inwardly, and the battery is assembled. In this battery, there are two places where the caustic electrolyte leaks, the contact surface between the negative electrode can and the gasket, and the contact surface between the positive electrode can and the gasket. In order to improve the mutual adhesion between them, the above-mentioned sealing conditions are optimized. Further, in order to further increase the caustic electrolyte leakage prevention effect, a liquid sealing material obtained by diluting process oil, petroleum asphalt, or the like with an organic solvent or the like is injected into the groove portion of the gasket (see, for example, Patent Documents 1 and 2).
JP 58-12259 A (1st page, FIG. 1) JP 59-2224048 (page 2, FIG. 1)

The leak-proof technology required for button-type batteries is becoming more sophisticated year by year, and it is an issue to maintain a high level of leak-proof characteristics for a long period of time. The caustic electrolyte is generated between the gasket and the creeping phenomenon of the negative electrode can on the copper surface of the negative electrode can.

  In order to make this gap as small as possible, the surface roughness of the battery can is reduced and smoothed, the strain under pressure accompanying the aging of the gasket is reduced, and the liquid with good adhesion to the battery can and gasket surface Application of sealing material, optimization, and two-stage sealing are performed, but leakage of caustic electrolyte cannot be suppressed over time.

  The negative electrode can according to the present invention forms a coating of a thiadiazole compound on the surface of the negative electrode can.

  Furthermore, the negative electrode can according to the present invention forms a film made of a thiadiazole compound on the surface of the copper or copper alloy of the negative electrode can.

  Preferably, the thiadiazole compound is 2,5-dimercapto-1,3,4-thiadiazole, 2-thioacetic acid-5-mercapto-1,3,4-thiadiazole, 2,5-thioacetic acid-1,3,4. -Any of thiadiazoles.

  A button type battery excellent in leakage resistance is manufactured using the negative electrode can according to the present invention.

  When the present invention is used, a negative electrode can excellent in sealing properties can be obtained by forming a film of a thiadiazole compound on the surface of the negative electrode can. Leakage of the alkaline electrolyte can be prevented by the coating formed on the negative electrode can. Furthermore, a button type battery having excellent leakage resistance can be obtained by using the negative electrode can on which the coating film is formed.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a button type battery according to the present invention. FIG. 2 is an enlarged sectional view of the sealing portion of the button-type battery according to the present invention.

  A positive electrode mixture 5 and a separator 6 are incorporated into the positive electrode can 1. Next, after the gasket 3 in which the liquid sealant is injected into the groove portion is inserted into the positive electrode can 1, the impregnating material 7 is placed, and then the negative electrode mixture 4 is added. Further, after injecting the caustic electrolyte, the negative electrode can 2 is united, the positive electrode can is caulked inwardly, and the battery is assembled.

  The negative electrode can 2 that also serves as a current collector is a clad material, and consists of three layers of a nickel layer 2a, a stainless steel layer 2b, and a copper layer 2c. A nickel layer 2a is provided to improve the lead with the contact spring of the mounted device, and the center is formed of the stainless steel layer 2b. Furthermore, in order to avoid zinc and Fe, Ni, Co, etc. forming a local battery on the inner surface side, the inner layer is made of a copper layer 2c having a high hydrogen overvoltage and is manufactured through a multi-stage pressing process.

  2,5-dimercapto-1,3,4-thiadiazole (hereinafter abbreviated as MTD), 2-thioacetic acid-5-mercapto-1,3, which is a thiadiazole compound, is formed on the surface of the copper layer 2c of the negative electrode can 2. A coating 2d formed by treatment with a solution containing 4-thiadiazole (hereinafter abbreviated as TMT) or 2,5-thioacetic acid-1,3,4-thiadiazole (hereinafter abbreviated as TMT-2) as a main component; MTD, TMT, TMT-2 and the surface of the copper layer react chemically and are densely and firmly bonded.

Here, the MTD, TMT, and TMT-2 are represented by the following structural formulas, and the forms of copper and the coating are Cu / Cu ₂ O _/ CuMTD, Cu / Cu ₂ O _/ CuTMT, Cu / Cu ₂ O _/ It is presumed to have a CuTMT-T structure.

  Next, the structural formula of MTD is shown in Chemical Formula 1.

化２は、TMTの構造式である。

Chemical formula 2 is the structural formula of TMT.

化３は、TMT−２の構造式である。

Chemical formula 3 is the structural formula of TMT-2.

通常、MTD、TMT、TMT-2ともに０．０５〜５重量％、好ましくは０．１〜１重量％のエチルアルコール（３０ｖ／ｖ％）水溶液に負極缶２を前記溶液中に浸漬し銅面２ｃに被膜を形成させた後乾燥し、強固な被膜２ｄを得ることが出きる。

Usually, both MTD, TMT, and TMT-2 are immersed in an aqueous solution of 0.05 to 5% by weight, preferably 0.1 to 1% by weight of ethyl alcohol (30 v / v%) in the negative electrode can 2 in the solution to obtain a copper surface. It is possible to obtain a strong coating 2d by forming a coating on 2c and then drying.

  In forming the above-mentioned film, the negative electrode can 2 is preliminarily degreased and acid-treated, and further subjected to a chemical polishing process (using CPB-10 and 55 manufactured by Hishie Chemical Co., Ltd.) (38 kHz, output 100 W). , Time 1-2 minutes) When the coating is formed after removing rust and scale, the grain boundary where the coating becomes discontinuous is reduced, and a denser and stronger coating 2d can be obtained and the leakage resistance is greatly improved. can do.

  If the coating 2d of the negative electrode can 2 is formed on the contact surface with the gasket 3, the creep phenomenon of the caustic electrolyte can be suppressed. However, it is troublesome to form a coating only at a specific portion as described above. Since it becomes a cost increase, forming in the whole copper layer 2c is preferable.

  In the above embodiment, the copper surface of the negative electrode can 2 that also serves as a current collector is chemically bonded to MTD, TMT, and TMT-2, and the copper surface is prevented from being oxidized. Furthermore, since the adhesiveness between the folded portion which is the gasket contact surface and the compound of these thiadiazole derivatives and copper is improved, the electrochemical creep phenomenon can be suppressed as a whole.

  Table 1 shows a sodium oxide aqueous solution (ZnO saturated) containing a silver (I) oxide positive electrode, a zinc alloy powder containing Al, Bi and In as a negative electrode and a stabilizer as an electrolytic solution, and 2,5-dimercapto-1,3. , 4-thiadiazole, 2-thioacetic acid-5-mercapto-1,3,4-thiadiazole and 2,5-thioacetic acid-1,3,4-thiadiazole treated negative electrode can (Diameter 6.8 mm, diameter 2.6 mm) Example 1, Example 2 and Example 3 were produced, respectively, and the results of evaluation of leakage resistance of a battery produced with a negative electrode can not subjected to surface treatment were shown as comparative examples. is there. The evaluation is performed under accelerated conditions of 60 ° C. and 90% Rh. The 20th and 40th days in the table correspond to a storage period of about 2 years and 4 years at room temperature and normal humidity (25 ° C., 65% Rh). To do.

表中の数値は各々の電池500個を試験した時の漏液発生率（％）である。この実験結果より、実施例１、実施例２、実施例３は比較例に比べ大幅に耐漏液性が改善されている。

The numerical values in the table are the leakage rate (%) when 500 batteries are tested. From this experimental result, the leakage resistance of Example 1, Example 2, and Example 3 is significantly improved compared to the comparative example.

It is sectional drawing of the button type battery which concerns on this invention. It is an expanded sectional view of the sealing part of the button type battery concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Positive electrode can 2 Negative electrode can 2a Nickel layer 2b Stainless steel layer 2c Copper layer 2d Coating 3 Gasket 4 Negative electrode mixture 5 Positive electrode mixture 6 Separator 7 Impregnation material

Claims (4)

  A negative electrode can, wherein a film of a thiadiazole compound is formed on a surface of the negative electrode can.   A negative electrode can, wherein a film made of a thiadiazole compound is formed on the surface of copper or a copper alloy of the negative electrode can.   The thiadiazole compound is 2,5-dimercapto-1,3,4-thiadiazole, 2-thioacetic acid-5-mercapto-1,3,4-thiadiazole, 2,5-thioacetic acid-1,3,4-thiadiazole. The negative electrode can according to claim 1, wherein the negative electrode can is any one.   A button-type battery using the negative electrode can according to any one of claims 1 to 3.

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