Abstract:

In order to develop high energy density battery materials with high energy density and superior cycle performance,the effect of Se doping amount on the microstructure and electrochemical properties of lithium-rich manganese based cathode materials was studied.Results showed that the increase of Se doping amount was helpful to reduce the particle size in the positive material,but if the Se doping amount is too high（x=0.21）,there will be serious particle aggregation;the appropriate Se doping amount in the cathode material of lithium battery was x=0.14,at this time,the cathode material with fine and uni-form particles can be obtained; the positive material with x=0.14 had the highest Coulomb efficiency due to the best inhibition of oxygen loss（77.1%）;when the ratio was at 0.1C~10C,the discharge specific capacity of the positive material increased first and then decreased with the increase of Se doping amount,and the maximum value was obtained when x=0.14,it showed that ratio performance of the positive material with x=0.14 was the best;the cycle performance of the positive material with x=0.14 was significantly higher than that of the positive material with x=0.4.

Key words: lithium battery, Se doping, electrochemical performance