Preparation And Characterization Of The Precursors Of Cobalt Oxide As The Lithium-ion Battery Anode Material

With the increasing of human demand for energy, what can be done to useenergy effectively and rationally attract more and more attention. The lithium-ionbatteries are consider as the sign of the electrical power source present. What can bedone to raise the utilization rates of electrical energy is the aim of every researcher.The electrical performance of the anode material take a tremendous influence on thelithium ions battery as the vital part of it. Cobalt oxide have higher capacity thancarbon material and lower price than precious metal oxide. So cobalt oxide is themain material to prepare anode material. The different topography cobalt oxide wassynthesized in this paper. There are three part of the experimental in this paper.(1) Well excellent electrical performance cobalt oxide anode materials isprepared in this paper by liquid precipitation method with cobalt sulfate as cobaltsource, hydroxide as precipitant and Poly Vinyl Pyrrolidone (PVP) as surfactant. Theeffect of concentration of cobalt sulfate solution, the mount of PVP and the calciningtemperature was studied. The structure and surface topography of the cobalt oxidepowder was expedition by X-ray powder diffraction and scanning electronmicroscopy. And the electrochemical performance of synthesized materials wascharacterized by electrochemical performance measurement. The results show thatcobalt hydroxide with uniform sheet structure particle size distribution is obtainedwith the concentration of cobalt sulfate solution0.2mol/L and PVP50%. The fineparticle size distributed cobalt oxide is obtained at calcining temperature of700℃for10h. And the cobalt oxide particle is sheet structure and its size is about3μm. Theinitial discharge capacity of the cobalt oxide is1500mAh/g and the dischargecapacity rethtion ratio is above90%after15cycles.(2) The rod-like structure cobalt oxide particle was synthesized with cobaltsulfate as cobalt source, the ammonium bicarbonate as precipitant and the Poly VinylPyrrolidone as surfactant. The effect of reaction temperature, the pH value of thereaction and the amount of the surfactant was studied. The structure and surfacetopography of the cobalt oxide powder was expedition by X-ray powder diffractionand scanning electron microscopy. The optimization process parameters was obtained. The rod-like (NH4)2Co8(CO3)4.H2O is synthesized when the temperature is60℃, pH value of the reaction is7.5and the amount of the surfactant is0.5g. Theuniform particle size, narrow distribution range rodlike particle is prepared aftercalcined for10h and the average particle size d(0.5) of the particle is4.438μm.（3）The sheet like precursor of which particle size is2-3μm was synthesizedby sluggish precipitation with0.1mol/L cobalt sulfate solution and0.3mol/L ureasolution mixed. The0.2g PVP as surfactant was added,the initial pH value wasregulate to5, the reaction temperature is100℃and the reaction time is4h。Thenthe globular particle with size between2~3was obtained by calcined.