Preparation method of cobalt-wrapped nickelous hydroxide

Abstract

The invention discloses a preparation method of cobalt-wrapped nickelous hydroxide. The preparation method comprises the steps as follows: (1) preparing a cobaltous sulfate solution A, a potassium hydroxide solution B, an ammonia solution C, a sodium hydroxide solution D, an aqueous solution E of salts from rare earth metals, and an aqueous solution of complexing agent F; (2) preparing spherical nickel hydroxide and pure water in a reactor to obtain the mixture, and adjusting the pH (Potential Of Hydrogen) of the reactive liquid through the solution B; (3) synchronously and continuously adding the solution A, the solution B, the solution C, the solution E and the solution F into the reactor to carry out wrapping reaction; (4) separating the solid from the liquid of the product prepared in step (3), washing via the pure water, and parching to obtain the nickelous hydroxide wrapped with cobaltous hydroxide; (5) adding the nickelous hydroxide wrapped with cobaltous hydroxide into an oxidizing reactor to be oxidized; and (6) washing the oxidized material via pure water, and parching to obtain the product of nickelous hydroxide wrapped with cobalt oxide. The cobalt-wrapped nickelous hydroxide prepared by the method provided by the invention has the characteristics of uniform wrapping and oxidizing layer, high conductivity, uniform and complete conductive network, and high utilization of active materials.

Description

technical field [0001] The invention relates to a preparation method of cobalt-coated nickel hydroxide, in particular to a preparation method of cobalt-coated nickel hydroxide for alkaline storage batteries. Background technique [0002] Nickel electrodes for alkaline storage batteries are mainly used as positive electrodes for secondary batteries such as cadmium-nickel, hydrogen storage alloy-nickel and zinc-nickel. Nickel hydroxide is the positive electrode active material of alkaline nickel-metal hydride batteries. Since nickel hydroxide itself is a semiconductor, a certain conductive agent must be added when making the plate, or a layer of cobalt compound must be coated on the surface to greatly improve the positive electrode performance. electrical conductivity. However, when the nickel-metal hydride secondary battery using this positive electrode active material is in the state of high current discharge, deep discharge, short circuit, etc., it often has the problem of...

AI Technical Summary

Problems solved by technology

However, when the nickel-metal hydride secondary battery using this positive electrode active material is in the state of high current discharge, deep discharge, short circuit, etc., it often has the problem of irrecoverable positive electrode capacity. The main reason is that the depth of nickel hydroxide During discharge, the conductive network substance β-CoOOH on the surface of nickel hydroxide will also undergo a partial reduction reaction, and the reduced divalent cobalt will form cobalt complex ions in the electrolyte of the battery, causing cobalt dissolution problems, thereby causing Incompleteness of the β-CoOOH conductive network

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