Performance of nano Li2FeSiO4/C cathode material co-doped by potassium and chlorine ions
Herein,the structure and electrochemical properties of nano Li2FeSiO4/C cathode materials were opti-mized through co-doping potassium and chlorine ions.A series of nano Li2-xKxFeSiO4-0.5xClx/C(x=0,0.01,0.02)com-posites were prepared by a solid-state reaction.The microstructure and electrochemical performance of the three kinds of composites were analyzed using X-ray diffraction,scanning electron microscopy,transmission electron microscopy,X-ray photoelectron spectroscopy,constant current charge-discharge test,etc.The results showed that nano Li1.99K0.01FeSiO3.995Cl0.01/C cathode material owned the largest interplanar spacing,biggest cell volume,and smallest average particle size among the three materials.The average particle size of nano Li1.99K0.01FeSiO3.995Cl0.01/C cathode material was as small as 32 nm.These particular structures made it exhibit the best electrochemical performance.The initial specific discharge capacity of the nano Li1.99K0.01FeSiO3.995Cl0.01/C cathode material at 0.1C was as high as 203 mAh·g-1.In addition,a capacity retention rate of 97.72％was acquired for the nano Li1.99K0.01FeSiO3.995Cl0.01/C cathode material at 1C after 100 charge-discharge cycles.
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