JPH03241672A - Cylindrical alkaline storage battery with nickel electrodes - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a cylindrical alkaline storage battery equipped with nickel electrodes using an electrolyte, particularly for industrial use. 4. Prior Art Lead-acid batteries and alkaline storage batteries are widely used as various power sources. It is used. Among these, alkaline storage batteries are well known as cylindrical batteries, and the representative one is the sealed nickel-cadmium type. The sealed type nickel-cadmium power supply mentioned above is
Because it is expected to be highly reliable and can be made smaller and lighter, it has been mainly used in various portable devices and emergency lights.Also, in cylindrical alkaline storage batteries, some silver oxide electrodes are being used as positive electrodes. In most cases, nickel electrodes are used as negative electrodes.Hydrogen is also considered as a negative electrode, but hydrogen has recently been attracting attention after cadmium.In this case, sintered type A paste type is also added.It has a closed cylindrical structure.The electrode and separator are wound in a spiral and inserted, and after injecting the electrolyte,
Manufactured with a seal.

However, although nickel electrodes have excellent charging and discharging characteristics, they are expensive due to the materials and processes involved, so there is a need to reduce the cost.One effective method is to add a conductive agent and a binder to nickel hydroxide powder and make it into a paste. A non-sintering method, which is obtained by coating this on a porous conductive thin plate and processing it into a sheet, has been widely studied, and many manufacturing methods have been proposed.

For example, in the case of nickel electrodes, a non-sintered type (conventional method) is obtained by adding a conductive agent and a binder to nickel hydroxide powder and applying it to a porous conductive thin plate and processing it into a sheet. (Nickel hydroxide, the active material of nickel electrodes, has almost no electronic conductivity, and the electrodes tend to swell with repeated charging and discharging.) Non-sintered nickel electrodes with a long lifespan have not yet appeared.Therefore, in order to increase the conductivity and improve the utilization rate of the active material, other conductive agents with excellent electronic conductivity are added, which also causes swelling and shedding of the active material. As a result, when using a separator impregnated with electrolyte as in a sealed type, there is less worry about the active material layer falling off, and paste-type nickel electrodes may also be used. On the other hand, for large-capacity batteries such as those for industrial use (to ensure reliability, space efficiency, and long life), the electrodes are made into rectangular shapes from the viewpoint of ensuring large discharge characteristics, and the electrodes are made into square shapes, with a separate electrode, a negative electrode, and an overlapping square electrode. The problem that the invention aims to solve is that it has a structure in which it is inserted into a cell and injects at least a larger amount of electrolyte than in a small sealed cylindrical battery. However, when paste-type non-sintered nickel electrodes are applied to this type of battery, they fall off so much that it is almost impossible to carry out industrial applications. However, it has not yet reached the stage where it can be used.Means for solving the problem The present invention (Dai) A laminate of a sheet-like nickel positive electrode, a separator, and a negative electrode mainly composed of a nickel electrode material and a rubber-based binder is formed into a spiral shape. The above problem is solved by a cylindrical alkaline storage battery with nickel electrodes, which is rolled up and inserted into a cylindrical battery case, and an electrolyte is injected into the battery case. (Above) This is a case where the battery is a nickel-cadmium storage battery or a nickel-hydrogen storage alloy storage battery, and the nickel electrode is obtained by adding a conductive agent and a rubber binder to nickel hydroxide and processing it into a sheet.

A separator and a negative electrode are sequentially layered on the nickel electrode obtained by adding a rubber binder and processing it into a sheet. This is then wound into a spiral and inserted into a cylindrical battery case to form a strong and uniform electrode. Pressure is applied to the active material layer, which can prevent the active material layer from falling off.

Example Using nickel hydroxide powder as the positive electrode material (8 wt% nickel powder, 8 wt cobalt powder, 6 wt unbound graphite powder, 9 wt% styrene-butadiene copolymer emulsion as a binder so that the resin content is 5 wt%) Add carboxymethyl cellulose as a thickener.
% aqueous solution so that the resin content is 1 wt % to obtain a paste at room temperature.

This was applied to a punched metal plate made of nickel-plated iron with a thickness of 0.17 mm, a hole diameter of 1.8 mm, and a porosity of 53%, passed through a 0.65 mm 11M slit, smoothed, dried for 1 hour, and then embossed. 0.6m thick through a roller press machine at 120℃
Adjust to m and width 13cm.

A well-known paste-type cadmium electrode was used as the negative electrode, which was cut to a length of 200 cm.The electrode was also 0.6 mm thick and 13 cm wide.The length was 240 cm, and the thickness was 0.6 mm at the nine centers. A 25 mm non-woven polypropylene separator treated with Oki was arranged and wound into a spiral and inserted into a cylindrical battery case made of nickel plated iron. After that, an aqueous solution of 25 g/l of lithium hydroxide dissolved in caustic potash with a specific gravity of 1.22 was applied to the electrode, which was about 1/2
Inject the liquid as an electrolyte until it is immersed. 15Kg/c
m'' to complete the battery by sealing the battery with a lid equipped with a safety valve to release gas.

The nominal capacity is 14Ah. This battery is called A.Next, for comparison, we used the same configuration as A, but regulated the amount of electrolyte to the extent that it impregnated the separator like a conventional cylindrical sealed battery (
16 c c) A battery was added as B. Also, for comparison, the area was 650 cm with the same electrode.
I made a 1L square battery with four positive electrodes and five negative electrodes.
The separator was the same, and the electrolyte was added in enough to submerge 1/2 of the positive electrode, and then sealed again.9 This was added as battery C.9 The discharge voltage and capacity of the above three batteries were compared.90, 2C constant current. Charge - 0,50 constant current discharge was performed &A, the average voltage was 1.21V,
The discharge capacity showed 14.5Ah, whereas B had a discharge capacity of 1.5Ah. 20V, 11. 2AhS C each 1. 20V, 14. 3Ah, and the initial characteristics of A and C were excellent.Next, we investigated the life characteristics under the same charging and discharging conditions.As a result, the number of cycles at which the discharge capacity deteriorated to 60% of the initial value was 800 to 850 for A. The cycle was 500 to 550 cycles/k for B, and 150 to 200 cycles for C.As is clear from these results, A had a high capacity and long life.In other words, B had a paste type nickel electrode. However, since the degree of expansion is greater than in conventional sintered batteries, electrolyte absorption progresses during the charging and discharging process, resulting in a shortage of electrolyte in the separator and a decrease in capacity. In case of C, the capacity decreases early due to lack of appropriate pressure in the electrode layer, which accelerates due to expansion of the battery case, and active material falls off. On the other hand, in A of the present application, the battery can be operated in a state where the electrolyte is abundant and the electrode and electrolyte layers are pressed together, so the battery has a high capacity and does not decrease in capacity even with a small number of cycles.

In the above embodiments, the case where the negative electrode is cadmium was described in detail, but it is Mm-Ni type (Mm is Mitsushi metal).
Exactly the same effect can be obtained with a nickel-hydrogen storage battery using a negative electrode made of a hydrogen storage alloy such as

Effects of the Invention As described above, in the present invention, a sheet-like nickel electrode made mainly of nickel electrode material and a rubber binder is used (a separator and a negative electrode are arranged, and the separator and negative electrode are arranged and wound into a spiral shape to form a cylindrical battery case. When inserted, enough electrolyte is injected to maintain the pressure that suppresses the expansion of the electrode, making it possible to provide an inexpensive alkaline storage battery with high utilization rate and long life.

Claims (3)

[Claims] (1) A laminate of a sheet-like nickel positive electrode, a separator, and a negative electrode, mainly made of nickel electrode material and a rubber-based binder, is spirally wound and inserted into a cylindrical container, and the electrolyte is poured into the container. A cylindrical alkaline storage battery with nickel electrodes characterized by injected nickel. (2) A cylindrical alkaline storage battery equipped with a nickel electrode according to claim 1, wherein the negative electrode is made of cadmium or a hydrogen storage alloy. (3) The cylindrical alkaline storage battery with a nickel electrode according to claim 1, wherein the nickel positive electrode is a sheet of a mixture of nickel hydroxide, a conductive agent, and a rubber-based binder.