JP2007026748A - Manganese battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manganese battery which has a high anti-leakage property, high preservation property during high temperature storage, and in which internal gas can be exhausted surely before the battery internal pressure reaches a sealing withstand pressure. <P>SOLUTION: This is the manganese battery 1 provided with a negative electrode zinc can 2, a positive electrode mixture 3, a carbon rod 8 as a positive electrode current collector, a sealed body 11 that seals the aperture of the negative electrode zinc can 2, and a positive electrode terminal plate 9 that is made to be fitted to the top part of the carbon rod 8, wherein the sealed body 11 is composed of a synthetic resin molded article in which an inner cylindrical part 12 that makes the carbon rod 8 penetrate through and an outer cylindrical part 13 that is fitted into the inner-circumference of the aperture of the negative electrode zinc can 2 are integrally coupled by the coupling part 14, and in which the outer cylindrical part 13 of the sealed body 11 is tightened and sealed between the outer peripheral part of the positive electrode terminal plate 9 and the caulking part 2a of the aperture end of the negative electrode zinc can 2. A gas discharge hole 16 is installed which has a thin-walled part and has a thick-walled part in which wall thickness gradually increases toward outside in the radial direction of its surrounding at the coupling part 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a manganese battery, and more particularly to a manganese battery that is sealed with a negative electrode zinc can without using an outer can and has a sealing body provided with a burst prevention mechanism.

  Cylindrical manganese batteries that do not use an outer can are fitted to the negative electrode zinc can, the positive electrode mixture, the carbon rod as the positive electrode current collector, the inner cylinder that penetrates the carbon rod, and the inner periphery of the opening of the negative electrode zinc can A sealing body made of a synthetic resin molded product integrally connected to the outer cylinder portion by the connecting portion, and a positive terminal plate fitted to the top of the carbon rod, and the outer cylindrical portion of the sealing body is connected to the positive terminal plate The battery is hermetically sealed by tightening between the outer peripheral portion of the electrode and the crimping portion of the open end of the negative electrode zinc can.

  For this reason, if the sealing body is not provided with a rupture prevention mechanism, hydrogen gas is generated inside the battery when the battery is accidentally charged, and as a result, the internal pressure of the battery rapidly increases, and the internal pressure of the battery However, there is a possibility that the sealing pressure resistance of the battery becomes larger and the sealing part of the battery is damaged and the battery is ruptured.

  Therefore, as shown in FIG. 6, a groove 25 extending vertically is formed on the inner peripheral surface 24 of the inner cylinder portion 23 through which the carbon rod 22 of the sealing body 21 passes, and a thin valve portion 26 is provided in the middle of the groove 25. What was formed is proposed (for example, refer patent document 1).

In addition, an alkaline battery in which a rupturable film having a thickness of 0.03 to 0.2 mm is provided at a joint between an inner cylinder portion and an outer cylinder portion of a sealing body made of polyamide or the like has been proposed (for example, Patent Documents). 2).
Japanese Utility Model Publication No. 7-32854 JP-T-2002-516462

  However, in the configuration provided with the explosion prevention valve described in Patent Document 1, the effect of preventing the explosion can be obtained. However, when stored at a high temperature, the valve portion 26 easily operates and moisture in the electrolyte is discharged from the battery. There is a problem that the liquid leaks outside and the electrolyte is depleted and dried, resulting in poor liquid leakage resistance and storage characteristics during high temperature storage.

  On the other hand, in the configuration described in Patent Document 2, since the sealable body is provided with a ruptureable film, the liquid leakage resistance and the storage characteristics at high temperature storage are high, but the ruptureable film having a thickness of 0.03 to 0.2 mm. Since the peripheral edge of the battery is connected to the peripheral wall of the hole formed in the sealing body, when the internal pressure of the battery is applied, the fracture location varies due to factors such as stress concentration at the corners. There is a problem that the disturbance factor is large, it is difficult to reliably rupture at a desired internal pressure of the battery, and the operation is unstable. Further, the sealing body made of polyethylene or polypropylene used for the sealing body of the manganese battery is 0. It is difficult to stably and accurately mold a rupturable film having a thickness of 2 mm or less with the configuration described in Patent Document 2, and a material that can be accurately shaped is expensive and inexpensive. In To use there is a problem that it is virtually impossible to become costly.

  In view of the above-mentioned conventional problems, the present invention provides a manganese battery that has high leakage resistance and high storage characteristics during high-temperature storage and can reliably release internal gas before the battery internal pressure reaches the sealing pressure resistance. Let it be an issue.

  The manganese battery of the present invention comprises a negative electrode zinc can, a positive electrode mixture, a carbon rod as a positive electrode current collector, a sealing body for sealing the opening of the negative electrode zinc can, and a positive electrode terminal plate fitted to the top of the carbon rod. The sealing body is made of a synthetic resin molded product in which an inner cylinder portion that penetrates the carbon rod and an outer cylinder portion that fits in the inner periphery of the opening of the negative electrode zinc can are integrally connected by a connecting portion, and the outer cylinder of the sealing body Is a manganese battery in which the portion is clamped between the outer peripheral portion of the positive electrode terminal plate and the crimped portion of the open end of the negative electrode zinc can and sealed, with the thinned portion at the connecting portion and the outer wall in the radial direction A gradually thickening portion in which the thickness increases is provided.

  According to this structure, since the thin part is provided in the connection part of the sealing body, liquid leakage does not occur unless the thin part is broken, and high leakage resistance and storage characteristics during high temperature storage are obtained. In addition, since the gradually thickened portion is provided around the thin-walled portion, the rupture point is the substantially central portion of the thin-walled portion, and the thin-walled portion reliably breaks when the battery internal pressure exceeds a predetermined pressure, and the battery As a rupture prevention mechanism, an effect that a stable operation can be expected is obtained. In addition, the gradually thickened part is provided around the thin part, so that the formability of the thin part is greatly improved, and it is molded with a synthetic resin of an inexpensive material generally used for a sealing body of a manganese battery. Even so, the thin-walled portion can be accurately molded, and high operating pressure accuracy can be ensured while maintaining low cost.

  In addition, when the breaking pressure of the thin-walled portion is 1 MPa or more and 80% or less of the pressure resistance of the sealing portion, liquid leakage during high-temperature storage can be surely prevented and high storage characteristics can be secured, and the sealing portion is damaged. The thin-walled portion is surely broken before the gas can be released safely.

  Further, by providing a gas exhaust port in the positive terminal plate, gas can be smoothly discharged from the positive terminal plate to the outside.

  Further, it is preferable that the sealing body is made of low-density polyethylene or polypropylene because it is inexpensive and has good moldability.

  According to the manganese battery of the present invention, since the thin portion is provided in the connecting portion of the sealing body, no leakage occurs unless the thin portion is broken, and good leakage resistance and storage characteristics during high temperature storage are obtained. In addition, since a gradually thickened portion is provided around the thin-walled portion, when the internal pressure of the battery exceeds a predetermined pressure, the thin-walled portion is surely broken at the center, and a stable burst prevention function is expected. In addition, the progressively thickened part is provided, so that the moldability of the thin part is greatly improved, and the thin part can be accurately molded even with inexpensive resin materials, ensuring high operating pressure accuracy while maintaining low cost. be able to.

  Hereinafter, a cylindrical manganese battery according to an embodiment of the present invention will be described with reference to FIGS.

  In FIG. 1, reference numeral 1 denotes a cylindrical manganese battery, in which a positive electrode mixture 3 is accommodated in a bottomed cylindrical negative electrode zinc can 2. A separator 4 is interposed between the positive electrode mixture 3 and the inner peripheral surface of the negative electrode zinc can 2, a lower insulating plate 5 is provided on the inner bottom surface of the negative electrode zinc can 2, and an upper insulating plate 6 is provided on the upper portion. The positive electrode mixture 3 is accommodated in a space surrounded by the separator 4 and the upper and lower insulating plates 5 and 6. Reference numeral 7 denotes a sealing pitch applied on the upper insulating plate 6.

  A carbon rod 8 serving as a positive electrode current collector is disposed at the center of the negative electrode zinc can 2, its lower end penetrates to the vicinity of the lower insulating plate 5, and its upper end projects from the upper edge of the negative electrode zinc can 2. ing. A positive terminal plate 9 is connected and fixed to the top of the carbon rod 8. Specifically, a terminal protrusion 9 a that protrudes from the center of the positive electrode terminal plate 9 is fitted to the top of the carbon rod 8. The outer peripheral portion of the positive terminal plate 9 is bent to have an L-shaped cross section, and a sealing flange portion 9c is formed via a falling portion 9b. A negative electrode terminal plate 10 is fitted and fixed to the bottom of the negative electrode zinc can 2.

  Between the inner periphery of the opening of the negative electrode zinc can 2 and the outer periphery of the upper end of the carbon rod 8, a sealing body 11 made of a molded product of low density polyethylene is disposed. As shown in FIG. 2, the sealing body 11 includes an inner cylinder part 12 through which the carbon rod 8 seals and penetrates, an outer cylinder part 13 fitted to the inner periphery of the opening of the negative electrode zinc can 2, and these inner cylinders. It is comprised by the connection part 14 which connects the lower parts of the part 12 and the outer cylinder part 13 integrally. On the inner peripheral upper part of the outer cylinder part 13, there is provided a seal protrusion 15 that is pressed in a compressed state on the upper surface of the sealing flange part 9 c of the positive terminal plate 9 disposed in contact with the connecting part 14. The sealing protrusion 15 is sealed by tightening between the sealing flange portion 9 c of the positive electrode terminal plate 9 and the caulking portion 2 a at the opening end of the negative electrode zinc can 2.

  One or a plurality of bottomed gas discharge holes 16 are recessed and formed in a region between the inner cylinder portion 12 and the sealing flange portion 9c in the connecting portion 14 of the sealing body 11. Further, the positive terminal plate 9 is provided with a gas exhaust port (not shown) through which the gas discharged from the gas discharge hole 16 is smoothly discharged to the outside.

The bottom wall of the gas discharge hole 16 is composed of a thin portion 17 at the center and a gradually thickened portion 18 in which the thickness gradually increases toward the outer periphery in the radial direction. The gradually thickening portion 18 is configured by C chamfering as shown in FIG. 3A, R chamfering as shown in FIG. 3B, and other appropriate inclined surfaces and curved surfaces. The dimensions of the thin portion 17 are set so that the breaking pressure is 1 MPa or more and 80% or less of the pressure resistance of the sealing portion. Although the specific dimensions differ depending on the battery specifications, they cannot be defined unconditionally. For example, in the case of R6 (AA) batteries and R06 (AA) batteries, the thickness t is 0.04 to 0.10 mm, the area. S1 is set to about 0.3 to 0.6 mm ² . Further, the chamfered dimensions C and R of the gradually thickened portion 18 are set to about 0.2 to 0.4 mm. FIG. 3C shows an example in which the entire bottom surface of the gas discharge hole 16 is formed by a thin portion 17 as a comparative example corresponding to Patent Document 2 of the conventional example.

  According to the above configuration, liquid leakage does not occur unless the thin-walled portion 17 provided in the connecting portion 14 of the sealing body 11 is broken, and high leakage resistance and storage characteristics during high-temperature storage can be obtained. The thickness and area of the portion 17 are set so as to break at a predetermined pressure set to a battery internal pressure of 1 MPa or more and 80% or less of the pressure resistance of the sealing portion, and a gradually thickening portion 18 is provided around the portion. Therefore, the broken portion becomes the substantially central portion of the thin-walled portion 17, and when the battery internal pressure becomes equal to or higher than the set pressure, the thin-walled portion 17 is surely broken, and the gas is surely released safely before the sealing portion is broken. Therefore, a stable operation can be expected as a mechanism for preventing explosion of the manganese battery 1.

  Furthermore, since the gradually thickened portion 18 is provided around the thin-walled portion 17, the moldability of the thin-walled portion 17 is remarkably improved, and an inexpensive low cost generally used for the sealing body 11 of the manganese battery 1. Even if it comprises density polyethylene, the thin part 17 can be shape | molded accurately, and high operating pressure precision can be ensured, maintaining low cost. In addition, as a molding resin of the sealing body 11, even if it uses polypropylene instead of the said low density polyethylene, it is cheap, its moldability is good, and there can exist the same effect.

  In the above embodiment, an example in which the thin portion 17 is configured by a flat surface having a predetermined area S1 is shown. However, the area of the thin portion 17 is reduced, and the gas discharge hole 16 is gradually combined with the thickened portion 18. A similar effect can be obtained by forming the bottom wall of the cone into a conical shape as shown in FIG. Further, as shown in FIGS. 4B and 4C, a conical apex may be formed so as to deviate from the center of the gas discharge hole 16. In the above description of the embodiment, an example in which the gas discharge hole 16 is formed in a U-shaped cross section that opens upward has been shown. However, the gas discharge hole 16 is formed in an inverted U-shaped cross section that opens downward. The same effect can be obtained.

  Next, examples and comparative examples of the present invention will be described.

(Experimental example 1)
In an R6 (AA) manganese battery, sealing is performed using a sealing body 11 injection-molded using low-density polyethylene without using a compression method, and the sealing portion pressure resistance is set to 3.92 MPa. The area of the thin portion 17 was fixed to 0.40 mm ² (circular shape with a diameter of approximately 0.71 mm), and the gradually thickened portion 18 was configured by R chamfering of 0.25 mm. And the battery which set the thickness of the thin part 17 to 0.04 mm (comparative example 1), 0.05 mm (example 1), 0.10 mm (example 2), and 0.12 mm (comparative example 2), respectively. Several were produced. For each example, as shown in FIG. 5, a plurality of batteries not filled with the positive electrode mixture 3 were prepared, and a gas filling hole was made in the side portion of the negative electrode zinc can 2, and the inside of the battery was The working pressure at which the thin-walled portion 17 of the sealing body 11 was broken was filled with gas.

And the following measurements and tests for each example,
Working pressure measurement: Working pressure was measured for 10 batteries as described above, and the average value was obtained. Safety test: 4 batteries were connected in series, and one of them was connected in reverse. 10 sets were prepared, and the case where the thin-walled portion 17 was broken and the gas inside the battery was released was activated, and the number was counted. Storage characteristics test: 10 batteries at 45 ° C in a constant temperature bath The open circuit voltage was then measured, and the number of the open circuit voltage was counted as the storage characteristic NG when the difference from the voltage before storage decreased by 50 mV or more.

上記測定及び試験の結果を表１に示した。なお、表１中の圧力比は、（作動圧力）／（封口部耐圧力）を％表示している。表１から、薄肉部１７の作動圧力が０．８２ＭＰａでは保存特性が悪く、１．１８ＭＰａでは保存特性が良好であることから、ほぼ１ＭＰａ以上あれば良好な保存特性が得られる事がわかる。また、上記圧力比が８０．０％以上あれば安全性試験で安定した作動が得られるが、それ以上になると作動が安定しないことが分かる。

The results of the above measurements and tests are shown in Table 1. In addition, the pressure ratio in Table 1 indicates (operating pressure) / (sealing pressure resistance) in%. From Table 1, it can be seen that the storage characteristics are poor when the operating pressure of the thin-walled portion 17 is 0.82 MPa, and the storage characteristics are good when the pressure is 1.18 MPa. Further, if the pressure ratio is 80.0% or more, a stable operation can be obtained in the safety test, but if the pressure ratio is more than that, it is understood that the operation is not stable.

(Experimental example 2)
In the R03 (AAA) manganese battery, the sealing portion pressure resistance is set to 5.90 MPa, the area of the thin portion 17 of the sealing body 11 is fixed to 0.30 mm ² (circular with a diameter of approximately 0.62 mm), and gradually The thickened portion 18 was constituted by R chamfering of 0.25 mm. And the battery which set the thickness of the thin part 17 to 0.03 mm (comparative example 3), 0.04 mm (example 3), 0.10 mm (example 4), and 0.12 mm (comparative example 4), respectively. Several were produced. Further, for each example, a plurality of batteries not filled with the positive electrode mixture 3 were prepared in the same manner as in Experimental Example 1, a gas filling hole was made in the side portion of the negative electrode zinc can 2, and the gas was put inside the battery. The working pressure at which the thin portion 17 of the sealing body 11 breaks was measured. Then, for each example, the measurement of the operating pressure, the safety test, and the storage characteristic test were performed in the same manner as in Experimental Example 1.

上記測定及び試験の結果を表２に示した。表２から、表１と同様に、薄肉部１７の作動圧力がほぼ１ＭＰａ以上あれば良好な保存特性が得られ、また上記圧力比が８０．０％以上あれば安全性試験で安定した作動が得られるが、それ以上になると作動が安定しないことが分かる。

The results of the above measurements and tests are shown in Table 2. From Table 2, as in Table 1, good storage characteristics can be obtained if the operating pressure of the thin portion 17 is approximately 1 MPa or more, and stable operation in the safety test is achieved if the pressure ratio is 80.0% or more. Although it is obtained, it is understood that the operation is not stable beyond this.

(Experimental example 3)
In the R6 (AA) manganese battery, a battery corresponding to Example 2 (thickness of the thin portion 17 is 0.10 mm, area is 0.4 mm ² ) is a basic configuration, and the gradually thickened portion 18 is 0.25 mm. 10 batteries were prepared for each battery (Example 5) in which the chamfering was changed from R-chamfering to C-chamfering of 0.25 mm, and only the thin-walled part 17 without forming the gradually thickened part 18 (Comparative Example 5). The working pressure was measured, the average value and variation were determined, and the fracture state of the thin wall portion was confirmed.

上記測定結果を表３に示した。表３からＲ面取りやＣ面取りによる漸次肥厚部１８を設けた実施例２、５では、作動圧力の標準偏差σが０．２５以下で、作動圧力が安定しているのに対して、漸次肥厚部１８を設けない比較例５では、作動圧力の標準偏差σが０．４３と大きくなり、破断圧力の平均値も低くなっていることが分かる。また、破断状態も、実施例のものはすべて薄肉部１７の中央部で破断していたが、比較例のものは中央部で破断しているものと周縁部で破断しているものとがあった。

The measurement results are shown in Table 3. In Examples 2 and 5 in which the gradually thickening portion 18 by R chamfering or C chamfering is provided from Table 3, the standard deviation σ of the operating pressure is 0.25 or less and the operating pressure is stable, whereas the gradually thickening is performed. In Comparative Example 5 in which the portion 18 is not provided, it can be seen that the standard deviation σ of the operating pressure is as large as 0.43 and the average value of the breaking pressure is also low. In addition, all the examples were broken at the central portion of the thin-walled portion 17, but the comparative example was broken at the central portion and at the peripheral portion. It was.

  INDUSTRIAL APPLICABILITY The present invention is useful for a manganese battery because it can provide a manganese battery with high leakage resistance and high storage characteristics during high-temperature storage and high reliability with respect to the battery burst prevention function at low cost.

The longitudinal cross-sectional view of one Embodiment of the manganese battery of this invention. Sectional drawing of the sealing body of the embodiment. 1 and FIG. 2 show a detailed configuration of part A, (a) is a configuration example of the embodiment, (b) is a modified configuration example, and (c) is a sectional view showing a configuration example corresponding to the conventional example. . Sectional drawing which shows another various various structural example of the thin part in the embodiment. The longitudinal cross-sectional view which shows the battery structure used for the working pressure measurement. The longitudinal cross-sectional view which shows the structure of the sealing body of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Manganese battery 2 Negative electrode zinc can 2a Caulking part 3 Positive electrode mixture 8 Carbon rod 11 Sealing body 12 Inner cylinder part 13 Outer cylinder part 14 Connection part 16 Gas discharge hole 17 Thin part 18 Gradually thickening part

Claims (5)

  A negative electrode zinc can, a positive electrode mixture, a carbon rod as a positive electrode current collector, a sealing body for sealing the opening of the negative electrode zinc can, and a positive electrode terminal plate fitted to the top of the carbon rod, the sealing body being a carbon rod A synthetic resin molded product in which an inner cylinder part that penetrates the outer cylinder part and an outer cylinder part fitted to the inner periphery of the opening of the negative electrode zinc can are integrally connected by a connecting part, and the outer cylinder part of the sealing body is connected to the outer periphery of the positive electrode terminal plate A manganese battery that is tightened and sealed between the squeezing part and the crimped part of the open end of the negative electrode zinc can, wherein the connecting part is a thin part and the gradually thickening part is gradually increased outward in the radial direction. And a manganese battery.   The manganese battery according to claim 1, wherein the breaking pressure of the thin wall portion is 1 MPa or more and 80% or less of the pressure resistance of the sealing portion.   The manganese battery according to claim 1 or 2, wherein a gas exhaust port is provided in the positive electrode terminal plate.   3. The manganese battery according to claim 1, wherein the sealing body is made of low density polyethylene. The manganese battery according to claim 1, wherein the sealing body is made of polypropylene.

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