JP7701785B2 - Alkaline batteries - Google Patents

Description

The present invention relates to an alkaline battery.

An alkaline battery has a cylindrical battery can, a positive electrode material stored in the battery can, a negative electrode material stored in the battery can, a cylindrical separator member that separates the positive electrode material from the negative electrode material, and a gasket member that seals the opening on the negative electrode terminal side of the battery can.

In alkaline batteries, the negative electrode material is stored and held within the separator member by injecting a gel-like negative electrode material into the cylindrical separator member through the opening on the negative electrode terminal side of the battery can.

JP 2001-351585 A

However, in conventional alkaline batteries, if the battery can is subjected to an external shock, for example by being dropped or being vibrated during transport, the shock can cause the negative electrode material to spill out from inside the separator member and come into contact with the positive electrode material. This can result in a short circuit between the negative electrode material and the positive electrode material, causing heat generation.

The disclosed technology has been developed in light of the above, and aims to provide an alkaline battery that can prevent short circuits between the negative electrode material and the positive electrode material.

One aspect of the alkaline battery disclosed in this application has a cylindrical battery can, a cylindrical positive electrode material loaded into the battery can along its inner circumferential surface, and a cylindrical separator member disposed inside the positive electrode material. The alkaline battery further has a cylindrical negative electrode material loaded inside the separator member, a gasket member that seals the opening of the battery can, and a partition plate that is disposed inside the separator member and separates the negative electrode material from the opening of the separator member.

According to one aspect of the alkaline battery disclosed in this application, short circuits between the negative electrode material and the positive electrode material can be prevented.

FIG. 1 is a vertical cross-sectional view showing an alkaline battery according to an embodiment of the present invention. FIG. 2 is a vertical cross-sectional view showing a main portion of the alkaline battery of the embodiment.

Below, examples of the alkaline battery disclosed in this application are described in detail with reference to the drawings. Note that the alkaline battery disclosed in this application is not limited to the following examples.

(Alkaline battery composition)
Fig. 1 is a cross-sectional view showing an alkaline battery of the embodiment. As shown in Fig. 1, the alkaline battery 1 of the embodiment is an aqueous solution primary battery, so-called a dry battery. The alkaline battery 1 includes a cylindrical battery can 3 having an opening 3a, a current collector 4, a positive electrode material 5, a negative electrode material 6, a separator member 7 separating the positive electrode material 5 and the negative electrode material 6, a gasket member 8 sealing the opening 3a of the battery can 3, and a partition plate 9. The alkaline battery 1 also includes, as electrode terminals, a positive electrode terminal 11 formed at one end of the battery can 3 and a negative electrode terminal 12 disposed at the other end of the battery can 3.

A positive electrode terminal 11 is integrally formed at one end of the battery can 3. At the other end of the battery can 3, a narrowed portion (beading portion) 3b is formed by beading along the outer periphery of the battery can 3. A negative electrode terminal 12 and a gasket member 8 are provided in the narrowed portion 3b of the battery can 3 so as to close the opening 3a. The current collector rod 4 is disposed in the center inside the battery can 3. The base end of the current collector rod 4 is supported by the gasket member 8, and the tip end extends toward the positive electrode terminal 11. The current collector rod 4 is formed, for example, from brass or the like.

The negative electrode material 6 is a cylindrical material provided around the current collector 4 inside the battery can 3, and is loaded inside the separator member 7. The negative electrode material 6 is, for example, a gel-like negative electrode mixture mainly composed of zinc. The positive electrode material 5 is loaded inside the battery can 3 along its inner circumferential surface. The positive electrode material 5 is provided on the outer circumferential side of the negative electrode material 6 contained inside the battery can 3, sandwiching the separator member 7. For example, a ring-shaped positive electrode mixture is used as the positive electrode material 5, and multiple ring-shaped positive electrode mixtures are stacked and arranged along the axial direction of the current collector 4. The separator member 7 is, for example, formed into a cylindrical shape using a nonwoven fabric, and is arranged inside the positive electrode material 5 and along the axial direction of the current collector 4.

Figure 2 is a vertical cross-sectional view showing the main parts of an alkaline battery 1 of the embodiment. As shown in Figure 2, the gasket member 8 of the alkaline battery 1 has a cylindrical central portion 15 as a support portion for supporting one end of the current collector rod 4, an annular safety valve 16 formed along the outer periphery of the central portion 15, and an annular outer peripheral portion 17 supported by the opening 3a of the battery can 3. The gasket member 8 also has an annular intermediate portion 18 formed between the safety valve 16 and the outer peripheral portion 17. The safety valve 16 is a groove-shaped thin-walled portion that is broken by the internal gas of the battery can 3.

The central portion 15 has a support hole 15a through which the current collector rod 4 passes, and as shown in FIG. 2, the current collector rod 4 is supported in the support hole 15a so that it contacts the negative terminal 12. The outer peripheral portion 17 is sandwiched between the vicinity of the narrowed portion 3b of the battery can 3 and the outer peripheral portion of the negative terminal 12, so that the gasket member 8 is supported by the battery can 3.

As shown in FIG. 2, the end of the separator member 7 abuts against the middle portion 18, and the space containing the negative electrode material 6 is blocked by the separator member 7.

The partition plate 9 is a metal plate disposed inside the separator member 7 and partitions between the negative electrode material 6 and the opening 10 of the separator member 7. Furthermore, the partition plate 9 presses the gel surface of the negative electrode material 6 in the separator member 7 from the opening side of the negative electrode terminal 12 and contacts the gel surface of the negative electrode material 6. In other words, the partition plate 9 partitions between the negative electrode material 6 and the opening 10 of the separator member 7, thereby preventing the negative electrode material 6 from spilling out from the opening 10. The partition plate 9 is a metal plate made of, for example, a zinc plate. Furthermore, the partition plate 9 has a support hole 9a that supports the current collector rod 4 inserted into the negative electrode material 6, and electrically connects the current collector rod 4 to the support part in the support hole 9a. Furthermore, the partition plate 9 contacts the gel surface of the negative electrode material 6 on the opening 10 side and electrically connects to the negative electrode material 6.

The alkaline battery 1 is structured such that the separator member 7 separates the negative electrode material 6 from the positive electrode material 5, and the partition plate 9 separates the negative electrode material 6 from the opening 10 of the separator member 7, thereby preventing short circuits between the negative electrode material 6 and the positive electrode material 5.

The partition plate 9 is disposed inside the separator member 7 and separates the negative electrode material 6 from the opening 10 of the separator member 7. As a result, even if the battery can 3 is subjected to some kind of impact, the partition plate 9 can prevent the negative electrode material 6 injected into the separator member 7 from spilling out of the opening 10.

In the alkaline battery 1 of this embodiment, a partition plate 9 that separates the negative electrode material 6 and the opening 10 of the separator member 7 is disposed inside the separator member 7. As a result, even if the alkaline battery 1 is subjected to an impact, the partition plate 9 prevents a short circuit caused by contact between the negative electrode material 6 and the positive electrode material 5, thereby providing an alkaline battery 1 with excellent safety.

The alkaline battery 1 has a partition plate 9 made of a zinc plate, which is electrically connected to a part of the current collector rod 4 inside the battery can 3. As a result, an alkaline battery with excellent discharge performance can be provided while increasing the current collection surface area.

(Test Example 1)
The following are the evaluation results of Test Example 1, which verified whether or not spillage of the negative electrode material 6 occurred due to vibration and dropping of each LR6 alkaline battery (AA alkaline battery). The vibration test is an evaluation test for confirming whether or not spillage of the negative electrode material 6 of the alkaline battery occurs, using the test method and test conditions stipulated in the transportation-vibration test of LR6 JIS C 8514 (Safety of Aqueous Primary Batteries), for example.

The drop test is an evaluation test in which, for example, an alkaline battery is allowed to freely fall from a height of 1 m five times from the positive electrode terminal 11, the negative electrode terminal 12, and the body of the battery can 3, and the presence or absence of spillage of the negative electrode material 6 is confirmed after leaving the battery stationary for one hour under each drop condition.

The alkaline battery of the conventional example does not have a partition plate 9. The alkaline battery 1 of the embodiment has a partition plate 9, and is of the embodiment's specification in which the partition plate 9 is made of a zinc plate. The alkaline battery 1 of the comparative example 1 has a partition plate 9, and is of the specification in which the partition plate 9 is made of a brass plate. The alkaline battery 1 of the comparative example 2 has a partition plate 9, and is of the specification in which the partition plate 9 is made of a resin plate.

As shown in Table 1, the conventional alkaline battery had the following evaluation results: spillage of the negative electrode material 6 occurred (○) in the vibration test, and spillage of the negative electrode material 6 occurred (○) in the drop test.

In contrast, in the alkaline batteries 1 of the Example, Comparative Example 1, and Comparative Example 2, the evaluation results showed that no spillage of the negative electrode material 6 occurred in the vibration test (×), and no spillage of the negative electrode material 6 occurred in the drop test (×).

In other words, in vibration tests and drop tests, in the case of an alkaline battery 1 having a partition plate 9, the negative electrode material 6 does not spill out, so short circuits caused by the negative electrode material 6 spilling out during impact can be suppressed. It was confirmed that an alkaline battery 1 having a partition plate 9 has the useful effect of preventing the negative electrode material 6 from spilling out.

(Test Example 2)
The following is an evaluation result of Test Example 2 of the discharge performance of each LR6 alkaline battery (AA alkaline battery). The discharge test is, for example, an LR6 JIS standard discharge test (based on JIS C 8515 individual product specifications for primary batteries). In the discharge test, for example, verification was performed under each condition of light load discharge, medium load discharge, and heavy load discharge.

For light load discharge, the discharge performance is verified, for example, with a load of constant current discharge of 100 mA/h. For medium load discharge, the discharge performance is verified, for example, with a load of constant current discharge of 250 mA/h. Furthermore, for high load discharge, the discharge performance is verified, for example, with a constant power discharge of 1500 mW.

In the discharge test, if the discharge performance is equivalent to that of the conventional example, it is marked as (△), if it is better than that of the conventional example, it is marked as (○), and if it is even better than that of the conventional example, it is marked as (◎). The discharge performance is considered to be gradually improved in the order of △ → ○ → ◎.

The alkaline battery of the conventional example does not have a partition plate 9. The alkaline battery 1 of the embodiment has a partition plate 9, which is made of a zinc plate, as in the embodiment. The alkaline battery 1 of the comparative example 1 has a partition plate 9, which is made of a brass plate. The alkaline battery 1 of the comparative example 2 has a partition plate 9, which is made of a resin plate.

In the alkaline battery 1 of Comparative Example 2, the discharge performance was evaluated (△) as being equivalent to that of the conventional example in all of the low-load discharge, medium-load discharge, and high-load discharge. In contrast, in the alkaline battery 1 of Comparative Example 1, the partition plate 9 is a brass plate, so the zinc-based negative electrode material 6, the brass current collector rod 4, and the brass partition plate 9 are electrically connected, and the surface area of the current collection portion is expanded. As a result, the alkaline battery 1 of Comparative Example 1 was evaluated (○) as having better discharge performance than the conventional example in all of the low-load discharge, medium-load discharge, and high-load discharge.

Furthermore, in the alkaline battery 1 of the embodiment, the partition plate 9 is a zinc plate, so that the zinc-based negative electrode material 6, the brass current collector rod 4, and the zinc plate partition plate 9 are electrically connected, and the surface area of the current collection portion is expanded. As a result, the alkaline battery 1 of the embodiment was rated as having better discharge performance (◎) than the alkaline battery of the comparative example 1 in all low-load discharge, medium-load discharge, and high-load discharge.

Therefore, in the alkaline battery 1 of the embodiment, the zinc-based negative electrode material 6, the brass current collector rod 4, and the zinc plate partition plate 9 are electrically connected, and it was evaluated that the surface area of the current collector is enlarged, thereby improving the discharge performance.

(Manufacturing process of alkaline battery 1)
The manufacturing process of the alkaline battery 1 constructed as above will be described in the order of steps.
(1) For example, a positive electrode mixture is prepared as the positive electrode material 5 using electrolytic manganese dioxide, graphite, a binder, and a potassium hydroxide solution, and the positive electrode mixture is molded into a ring shape.
(2) A gel-like negative electrode mixture is prepared as the negative electrode material 6 using zinc alloy powder, an electrolyte, etc.
(3) A ring-shaped positive electrode mixture is placed inside the battery can 3.
(4) A constricted portion 3b is formed at the end of the battery can 3 by beading, and a sealant is applied to the contact surface between the gasket member 8 and the battery can 3.
(5) The separator member 7 is inserted inside the positive electrode mixture contained in the battery can 3.
(6) The separator member 7 is impregnated with a potassium hydroxide electrolyte.
(7) A gelled negative electrode mixture is injected into the inside of the separator member 7 provided in the battery can 3 through the opening 3 a on the negative electrode terminal 12 side.
(8) A current collector is prepared by assembling the partition plate 9, the gasket member 8, the current collector rod 4, and the negative electrode terminal 12.
(9) The current collector is attached to the opening 3a of the battery can 3 so that the partition plate 9 presses down the gel surface of the negative electrode material 6 injected into the separator member 7, and the opening 3a is sealed with the current collector.

(Effects of the embodiment)
The alkaline battery 1 of this embodiment is provided with a partition plate 9 that separates the negative electrode material 6 from the opening 10 of the separator member 7. As a result, by preventing the negative electrode material 6 from spilling out into the opening 10, the occurrence of a short circuit between the negative electrode material 6 and the positive electrode material 5 is suppressed, and an alkaline battery 1 with excellent safety can be provided.

In the alkaline battery 1 of this embodiment, the zinc plate partition plate 9 and the current collector rod 4 are electrically connected. As a result, the surface area of the current collector portion is increased, providing an alkaline battery 1 with excellent discharge performance.

In the alkaline battery 1 of this embodiment, the gel surface of the zinc-based negative electrode material 6 is brought into contact with the zinc plate partition plate 9, electrically connecting the partition plate 9 and the negative electrode material 6. As a result, the surface area of the current collecting portion is increased, providing an alkaline battery 1 with excellent discharge performance.

(Modification)
For ease of explanation, a zinc plate is exemplified as the partition plate 9 of the alkaline battery 1, but the present invention is not limited to a zinc plate and may be a resin plate. In this case, the resin partition plate 9 separates the negative electrode material 6 in the separator member 7 from the opening 10, thereby preventing the negative electrode material 6 from spilling out into the opening 10.

In addition, although a zinc plate is exemplified as the partition plate 9 of the alkaline battery 1, it is not limited to a zinc plate and may be a metal plate such as brass. In this case, the partition plate 9 not only prevents the negative electrode material 6 from spilling out into the opening 10, but also electrically connects the metal partition plate 9, the current collector rod 4, and the negative electrode material 6, thereby expanding the surface area of the current collecting portion and improving discharge performance.

REFERENCE SIGNS LIST 1 alkaline battery 3 battery can 3a opening 4 current collector rod 5 positive electrode material 6 negative electrode material 7 separator member 8 gasket member 9 partition plate 10 opening 12 negative electrode terminal

Claims (3)

A cylindrical battery can;
A cylindrical positive electrode material is loaded into the battery can along its inner circumferential surface;
a cylindrical separator member disposed inside the positive electrode material;
A cylindrical negative electrode material is loaded inside the separator member;
a gasket member that seals an opening of the battery can;
a partition plate that is a metal plate and is disposed inside the separator member to separate the negative electrode material from an opening of the separator member ;
The partition plate is
An alkaline battery in electrical communication with the negative electrode material by contacting the gel surface of the negative electrode material. The metal plate is
2. The alkaline battery of claim 1 which is a zinc plate. The partition plate is
3. The alkaline battery of claim 1, further comprising a current collector inserted into the negative electrode material and electrically connected to the current collector.

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