Preparation method of flaky nano beta-Co(OH)2

Abstract

The invention discloses a method for preparing flaky nano beta-Co(OH)2 by utilizing an electrolytic method. The method includes: the solution containing Co<2+> is fed into an electrolysis device, wherein the electric energy is provided by direct current power supply, a platinum needle electrode sealed in the quartz tube is used as an anode, and the capillary tube penetrates into the graphite carbon rod and liquid overflowing from the top end of the capillary tube is a cathode; a solution containing Co<2+> flows through the buffer bottle under the driving of the peristaltic pump and overflows from the top end of the capillary tube; then a voltage of 80-220 V is applied to between the cathode and the anode for electrolyzing the solution overflowing from the top end of the capillary tube to obtain a dark brown turbid solution; after continuous electrolysis for 3-5 hours, the dark brown turbid solution is subjected to ultrasonic dispersion, centrifugation, washing, drying and milling to obtain the nano beta-Co(OH)2 with the sheet structure. The preparation method has the advantages that the flaky beta-Co(OH)2 nanoparticles with different particle sizes can be obtained by regulating andcontrolling the electrolyte concentration, the electrolysis voltage, the electrolysis time and the like; the product has the advantages of few impurities, high purity, good crystallinity and convenient separation, and is a novel environment-friendly green preparation technology of the flaky beta-Co(OH)2 nanoparticles.

Description

technical field [0001] The invention belongs to the technical field of preparation of nanomaterials, in particular to an electrolysis method directly preparing flake nano-β-Co(OH) from a cathode cobalt nitrate solution 2 Methods. Background technique [0002] Co(OH) 2 With its high theoretical specific capacitance (5191F / g), it is considered to be one of the electrode materials with the most development potential, and it is the core raw material for preparing rechargeable batteries such as Ni-Cd, MH-Ni and lithium-ion. In MH-Ni batteries, add 1% to 5% Co(OH) 2 The conductivity of the electrode can be enhanced, and the O 2 The precipitation potential, thereby improving the charge and discharge efficiency and cycle life. In addition, Co(OH) 2 It is also the preparation of lithium-ion battery cathode material LiCoO 2 excellent precursor; at the same time, Co(OH) 2 It is also the raw material for the preparation of cobalt compounds. Co(OH) 2 There are mainly two structu...

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Problems solved by technology

Among them, chemical precipitation method, hydrothermal method, solid phase reaction method and electrochemical deposition method are currently researched relatively mature preparation methods, but in Co(OH) 2 During the preparation process, Co(NO 3 ) 2 ·6H 2 O. CoSO 4 etc. are cobalt salt precursors, using ammonia solution as a precipitant, reacting under the protection of an inert gas, the process is complex, expensive, prone to secondary pollution, and has high requirements for process conditions and production equipment

The glow discharge plasma method can effectively solve the above-mentioned preparation of Co(OH) 2 defects, Lu Quanfang et al. used cobalt sheets as anodes, needle-shaped platinum wires as cathodes, and NaNO 3 The solution is an electrolyte, and the sheet-shaped nano-β-Co(OH) was successfully prepared by using the liquid-phase cathode glow discharge plasma technology. 2 , although this method has outstanding advantages, it uses cobalt flakes as the anode, which consumes a lot of power during the preparation process, and the Co 2+ The concentration of the solution is not easy to control, resulting in the obtained β-Co(OH) 2 The particle size of nanoparticles is difficult to control

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