Method for coating and mixing metal M alpha-Co(OH)2 on ball shape nickel hydroxide surface

Abstract

The invention relates to a technology for cladding a-Co(OH)2 on spheral nickel hydroxide. Tap density of prepared cobalt coated spheral nickel hydroxide can reach about 2.2g / cm3. The main method is to clad a layer alpha-Co(OH)2 mixed with one of more than one metal M from Y, Al, Cr, Mn, Yb, Sc, La, In, Ti, Zn, when (Co+M) / Ni ratio (mole ratio) is 0.3-0.1, conductive performance of sphere nickel hdyroxide product is abvisouly improved, Ni(OH)2 electrode performance is increased, further the cell performance as specific capacity, out power, charge-discharge circulating life, rapid charging ability, over charge / discharge resistance ability and oxygen separating overtention etc. are obviously increased.

Description

technical field [0001] The invention belongs to the field of new chemical material preparation. In particular, it relates to a kind of α-Co(OH) coated with metal M doped on the surface of spherical nickel hydroxide 2 Methods Background technique [0002] Spherical nickel hydroxide is a positive electrode active material for alkaline rechargeable batteries such as nickel-hydrogen batteries. At present, nickel-hydrogen batteries have been widely used in electronics, communications and other fields, and have shown good application prospects in the field of electric vehicles. But due to Ni(OH) 2 It is a low-conductivity p-type semiconductor, with low charge / discharge efficiency, poor electrode performance, and reduced battery capacity. In order to improve the utilization rate of the active material and its conductivity with the current collector, generally when making electrodes, Ni( Oh) 2 Add appropriate amount of Ni powder, Co powder, CoO powder or Co(OH) 2 Powder as a c...

AI Technical Summary

Problems solved by technology

However, the plated nickel film will gradually oxidize to Ni(OH) during charge and discharge. 2 Participating in the charging and discharging process of the battery, the conductive network formed by the conductive nickel film is thus destroyed, resulting in a sharp decline in battery performance; and the plated cobalt film will generate Co(OH) 2 and finally converted to CoOOH with high conductivity

However, from the perspective of the electroless plating process, its operating conditions are very harsh, and precious metals need to be used as catalysts, resulting in increased product costs and environmental pollution. Therefore, this process is limited in industrial production.

[0005] It is also possible to coat β-Co(OH) on the surface of spherical nickel hydroxide by chemical methods 2 , but the coated β-Co(OH) 2 The activation speed is slow, and it must be oxidized to highly conductive CoOOH before use, but the oxidation process is more complicated