Preparation method and application of nitrogen-doped CoB alloy

Abstract

The invention discloses nitrogen-doped CoB alloy. The nitrogen-doped CoB alloy is prepared by the steps of reducing a mixed solution of cobalt chloride and a nitrogen-containing alkali compound by virtue of a sodium borohydride solution under an ultrasonic condition, and carrying out washing and vacuum drying; and the specific surface area is 20m<2> / g-50m<2> / g, and the diameter range of particles is 300nm-600nm. When the nitrogen-doped CoB alloy is used as a battery cathode material, a primary specific discharge capacity value reaches 500mAh / g-1000mAh / g under the charging current density of electrochemistry capacity of 100mA / g; and after 100 times of circulation, the specific discharge capacity value is 300mAh / g-500mAh / g, the capacity retention ratio is 30%-50%, and the limiting diffusion current density is 1000mA / g-6000mA / g. A preparation method of the nitrogen-doped CoB alloy comprises the following steps: (1) dissolving cobalt chloride and the nitrogen-containing alkali compound into water, so as to obtain a mixed solution; (2) preparing a sodium borohydride solution, and dropwise adding the sodium borohydride solution into the mixed solution in the step (1) at a certain speed, so as to obtain black turbid liquid; and (3) filtering the black turbid liquid, washing, and drying. The nitrogen-doped CoB alloy is uniform in particle distribution, has excellent electrochemical and kinetic properties and further has wide application prospects in the fields of secondary cells, super-capacitors and the like.

Description

technical field [0001] The invention relates to the technical field of alkaline secondary batteries, in particular to a preparation method and application of a nitrogen-doped CoB alloy. Background technique [0002] Alkaline secondary battery is a general term for secondary batteries with alkaline aqueous solution such as potassium hydroxide as electrolyte, mainly including nickel-cadmium, nickel-metal hydride, nickel-zinc, zinc-manganese, nickel-iron and zinc-silver batteries, because of their low price , high specific energy, high power, good safety performance, wide operating temperature range and other characteristics, it has been widely used in communications, lighting and electric tools in recent years. The negative electrode materials of alkaline secondary batteries are mainly metals or alloys. In recent years, researchers have found that cobalt and cobalt-based alloys have relatively excellent electrochemical properties, such as CoB, CoSi, CoP, CoS and Co-Si 3 N 4 ...

AI Technical Summary

Problems solved by technology

However, in the current research (Metals 2016, 6: 269), the alloy still has low electrochemical capacity (when the discharge current density is 100 mA / g, the discharge specific capacity is 306.4 mAh / g after 100 cycles), poor cycle stability (100 The capacity retention rate at the second time is 36.28%), the particles are prone to agglomeration and other technical problems

Images