Study On Preparation Of Sub-micron Carbonate Manganese And Manganese Phosphate

In this paper, the synthesis process of manganese carbonate has been studied, using the manganese sulfate and ammonium bicarbonate as raw materials. Discussed factors such as the types and ratio of surfactants, the ratio of raw materials, the concentration of reactant, the reaction temperature, the reaction time, the reaction solution pH value and so on, on the influence of the average particle size and morphology of preparation of manganese carbonate. Through the single factor experiment, orthogonal experiment, the response surface analysis,got the best technological conditions, and verified, the best process conditions is:the surfactant ratio is0.046, the ammonium bicarbonate concentration is1.0mol/L, the manganese sulfate concentration is1.1mol/L, the reaction temperature is60℃, the reaction time is40min, the ratio of carbon and manganese (CO32-:Mn2+) is1.6:1, V/V (C2H6O)(H2O)=1:1, the PH value is7.0. Under this condition of the process, the preparation of manganese carbonate is spherical, particle size distribut uniform, the average particle size is582nm, accord with the requirement of sub-micron.Use manganese carbonate,which preparated by myself, as the precursor, and mixed with lithium carbonate and calcinated together,got Manganese acid lithium, and tested the electrochemical performance of electrochemical performance. The discharge specific capacity for the first time,under the three ratio of0.2C,0.5C,1.0C, is139.65mAh/g,132.56mAh/g and123.39mAh/g. The discharge specific capacity retention after looped80times, under the three ratio of0.2C,0.5C,1.0C,is94.82%,93.49%,90.51%.In this paper, the synthesis process of manganese phosphate has been studied, using the manganese sulfate and phosphoric acid as raw materials. Discussed factors such as the types of surfactants, the ratio of raw materials, the concentration of reactant, the reaction temperature, the reaction time, the reaction solution pH value and so on, on the influence of the average particle size and morphology of preparation of manganese phosphate. Through the single factor experiment, orthogonal experiment, got the best technological conditions, and verified. The best process conditions is:the temperature is80℃, the molar weight ratio of phosphorus and manganese is1.5:1, dosage of CTAB is1.0%of manganese salt quality, the raw material drop add time is30min, the value of pH is8.0. Under this condition of the process, the preparation of manganese carbonate is flake, particle size distribut uniform, the average particle size is815nm, accord with the requirement of sub-micron.Use manganese phosphate,which preparated by myself, as the precursor, and mixed with lithium carbonate and calcinated together,got Lithium manganese phosphate, and tested the electrochemical performance of electrochemical performance. The discharge specific capacity for the first time,under the three ratio of0.1C,0.5C,1.0C, is102.37mAh/g,97.62mAh/g and88.76mAh/g. The discharge specific capacity retention after looped80times, under the three ratio of0.1C,0.5C,1.0C,is93.21%,88.75%,83.02%.