Ti3SiC2偶合C改性Li3V2（PO4）3正极材料低温充放电性能研究

Study on Low Temperature Charge and Discharge Performance of Ti3SiC2 Coupled C Modified Li3V2 （PO4）3 Cathode Material

文章通过采用控制pH值为4的溶胶-凝胶法制备C包覆Li3V2(PO4)(Li3V2(PO4)3/C)正极材料,再利用聚乙烯醇辅助的悬浮包覆法对其进行不同含量的Ti3SiC2包覆,研究了C和Ti3SiC2偶合改性Li3V2(PO4)3正极材料制备工艺以及在常温、0℃和–20℃对Li3V2(PO4)3充放电性能。结果表明,Ti3SiC2和C偶合改性是提高Li3V2(PO4)3低温充放电性能的一种有效方法,在3.0-4.8V电压窗口下Ti3SiC2包覆量为4%(质量分数)时,材料具有最好的充放电性能,适量的Ti3SiC2包覆可以同时提高材料的锂离子扩散系数和电子电导。

In this paper,c-coated Li3V2(PO4)(Li3V2(PO4)3/C)positive electrode material was prepared by sol-gel method with pH value controlled to 4,and then Ti3SiC2 with different content was coated by polyvinyl alcohol-assisted suspension coating method.The preparation process of c-Ti3SiC2 coupling modified Li3V2(PO4)3 positive electrode material and its charging and discharging performance at normal temperature,0℃ and-20℃ were studied.The results show that the coupling modification of Ti3SiC2 and C is an effective method to improve the charging and discharging performance of Li3V2(PO4)3 at low temperature.The material has the best charging and discharging performance when the Ti3SiC2 coating amount is 4%(mass fraction)under the voltage window of 3.0-4.8 V.Appropriate Ti3SiC2 coating can simultaneously improve the lithium ion diffusion coefficient and electronic conductivity of the material.