The Synthesis Of NCA Lithium Ion Battery Cathode Material

The nickel-rich cathode materials Li1.05Ni0.85Co0.15Al0.03O2 has been considered as the substitution for Li Co O2 for it owns the advantages such as high specific capacity,high cycle stability and good thermal stability.However,the loss of capacity during the cycle process,and the decrease of circulation performance.The high temperature solid phase synthesis method is used in this paper to synthesis Li1.05Ni0.85Co0.15Al0.03O2 ? Li0.95Na0.1Ni0.85Co0.15Al0.03O2 ? Li1.05Ni0.85Co0.15Al0.03 O2(Li F)0.05.In order to improve the electrochemical properties of Li1.05Ni0.85Co0.15Al0.03O2,the lithium source,synthesis temperature,cation doping,surface modification on Li1.05Ni0.85Co0.15Al0.03O2 were investigated.Li OH·H2O and Ni0.85Co0.15Al0.03(OH)2 were synthesized by high temperature solid phase calcined at different temperatures.Li1.05Ni0.85Co0.15Al0.03O2 calcied at 700? has the best structure morphology,and then doping the samples synthesized at 700? by La?Ti?Cr?Zr(mole ratio:1:003)?Research shows that the discharge specific capacity and cycle stability of the materials after doping has improved.the Ti-doped material have the best electrochemical performance.In the range of 3-4.5V voltage,the initial discharge specific capacity of the Ti-doped Li1.05Ni0.85Co0.15Al0.03O2 calcied at 700 ? 192.7m Ah/g,and 90.7% of the initial discharge capacity was maintained after 100 cycles.We use Al2O3?Ti O2?Mg O?Zn O?Ce O2?Zr O2?Y2O3?Nb2O5 to modify the Li1.05Ni0.85Co0.15Al0.03O2 calcied at 700?,The results show that,a layer of protective film is formed on the surface of the coated material,which effectively prevents the corrosion of the electrolyte from the electrode material.The coated material the initial discharge specific capacity and cycle stability are improved,the coated Ce O2 has the best electrochemical properties.In the range of 3-4.5V voltage,the initial discharge specific capacity of the Ti-doped Li1.05Ni0.85Co0.15Al0.03O2 calcied at 700 ? 185.9m Ah/g,and 84.5% of the initial discharge capacity was maintained after 100 cycles.Li1.05Ni0.85Co0.15Al0.03O2(Li F)0.05 were synthesized by high temperature solid phase calcined at different temperatures.Li1.05Ni0.85Co0.15Al0.03O2 calcied at 700? has the best electrochemical properties.In the range of 3-4.5V voltage,the initial discharge specific capacity of Li1.05Ni0.85Co0.15Al0.03O2 calcied at 700 ? 197.7m Ah/g,and 55.6% of the initial discharge capacity was maintained after 100 cycles.Doping the Li1.05Ni0.85Co0.15Al0.03O2(Li F)0.05 calcined at 700? by La?Ti?Cr?Zr(mole ratio:1:003)?The results show that proper doping improves the cyclic stability of the material.The Zr-doped material have the best electrochemical performance.In the range of 3-4.5V voltage,the initial discharge specific capacity of the Ti-doped Li1.05Ni0.85Co0.15Al0.03O2 calcied at 700 ? 197.2 m Ah/g,and 86% of the initial discharge capacity was maintained after 100 cycles.We use Al2O3?Ti O2?Mg O?Zn O?Ce O2?Zr O2?Y2O3?Nb2O5 to modify the Li1.05Ni0.85Co0.15Al0.03O2(Li F)0.05 calcied at 700?,After the surface modification,initial discharge specific capacity was decreased,and the cycle stability was not improved.A small amount of Na was used to replace the Li synthetic material and to explore the optimum synthesis temperature.Li0.95Na0.1Ni0.85Co0.15Al0.03O2 calcied at 800? has the best electrochemical properties.the initial discharge specific capacity of the Ti-doped Li1.05Ni0.85Co0.15Al0.03O2 calcied at 700 ?191m Ah/g,and 60.0% of the initial discharge capacity was maintained after 100 cycles.