JPH012256A - Manufacturing method of cathode plate for sealed alkaline storage battery - 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 Field of the Invention The present invention relates to an improvement in a method for manufacturing a cathode plate for a sealed alkaline storage battery.

BACKGROUND OF THE INVENTION Conventionally, non-sintered cadmium cathode plates have been produced by forming an active material into a paste using a binder and a solvent, and applying the paste to a core. However, due to the recent marketability of rapid charging, it has become essential to manufacture a sealed alkaline storage battery with greatly improved rapid charging performance by improving the ability of the cathode plate to absorb oxygen gas during rapid charging.

Therefore, in order to manufacture a cathode plate with improved oxygen gas absorption ability, it has been proposed to add nickel flakes as a conductive material to the active material, or to apply a conductive layer of carbon powder on the surface of the active material layer. There is.

Problems to be Solved by the Invention In the above manufacturing method, the method of adding nickel flakes to the active material lowers the energy density and the nickel flakes are dispersed in the active material in order to sufficiently satisfy the effect as a conductive agent. However, the method of applying carbon powder to the surface of the active material layer has poor workability as the carbon powder falls off and scatters, so there are disadvantages such as charging does not proceed uniformly over the entire electrode plate. This method has drawbacks such as requiring extra steps.

Means to solve problems The present invention eliminates the above-mentioned drawbacks.

A paste-like active material to which spongy metal cadmium powder is added is also applied to the surface of the hind limb coating layer, which is made by applying a paste-like active material to the core body.

The charging reaction near the surface of the working electrode progresses through the spongy metal cadmium powder, which makes it easier for metal cadmium to be generated near the surface of the electrode, so oxygen gas is quickly absorbed near the surface of the electrode. Therefore, it is possible to greatly improve the oxygen gas absorption capacity.

Example: Approximately 1 nickel powder was added as a conductive material to cadmium oxide powder.
The active material, which was made into a paste by adding DVA powder as a binder (approx. Apply to thickness. Next, about 10 wt1 of spongy metal cadmium powder was added to the cadmium oxide powder, and the active material made into a paste was applied to the surface of the coating layer to a coating thickness of 115 mm, followed by hot air at about 150°C. Dry for 15 minutes in
Obtain a paste type cathode plate.

The cathode plate obtained in the above example was combined with a sintered anode plate via a separator, and a sealed nickel-cadmium battery A was assembled by a conventional method. The sealed nickel-cadmium battery A of the present invention and a conventional sealed nickel-cadmium battery B, which was assembled in the same manner using a conventional cathode plate, were charged at 0°C for 5 hours at a rate of 1[flow]. Continuous charging was performed, and the gas pressure inside the m-cell was measured with a pressure gauge attached to the battery can. The drawing shows the relationship between the charging time and the gas pressure inside the battery for a sealed nickel-cadmium battery A of the present invention and a conventional nickel-cadmium battery B.

Effects of the Invention As described above, the present invention provides a method of applying a paste-like active material layer containing spongy metal cadmium to the surface of a paste-like active material layer mainly composed of cadmium oxide applied to a core. By.

It is possible to produce a cathode plate which rapidly absorbs oxygen gas near the surface of the cathode plate, and whose oxygen gas absorption capacity is greatly improved, which is of great industrial value.

[Brief explanation of drawings]

The drawing is a comparison diagram of the gas pressure inside the battery during continuous charging between a sealed nickel-cadmium battery using the cathode plate obtained by the present invention and a sealed nickel-cadmium battery i-cell using the cathode plate obtained by the conventional method.

Claims (1)

[Claims] In a method of manufacturing a cathode plate by adding a binder, a conductive material, and a solvent to cadmium oxide, mixing the active material into a paste, applying it to a core, and then drying to scatter the solvent,
A cathode for a sealed alkaline storage battery, characterized in that after applying a paste-like active material, a sponge-like metal cadmium powder is added to the paste and mixed to form a paste-like active material, which is then applied onto the applied layer. Method of manufacturing the board.