锂离子电池正极材料磷酸钒锂的改性研究

Modification of Li_3V_2(PO_4)_3 cathode material for lithium ion batteries

近年来,作为锂离子电池正极的磷酸盐材料因为其结构稳定,循环性能优良,受到研究者的普遍关注。磷酸钒锂理论容量为197mAh/g,具有较高的能量密度和充放电电压平台,热稳定性好,相比其它正极材料具有明显的优势。但是磷酸钒锂电子电导率较低,且不适合大电流充放电的缺点限制了其实际应用,必须对其进行改性研究。目前改性方法主要包括表面包覆导电材料,金属掺杂,控制形貌特征等。结合磷酸钒锂的结构,综述了各种改性方法的工艺及优缺点,结合本研究团队关于磷酸钒锂改性的研究成果探讨了目前存在的问题及今后的研究趋势。

In recent years,poly anionic phosphate cathode materials for lithium ion batteries are widely con-cerned by the researchers because of their stable structure and excellent cycling performance.Lithium vanadium phosphate has the theoretical capacity of 1 9 7 mAh/g.It has high energy density,high charge and discharge voltage platform and excellent thermal stability.Compared to other cathode materials,it has obvious advanta-ges.But its electronic conductivity is low and not suitable for high current charge and discharge,which limits its practical application,we must carry on the modification research.Current modification methods include coating conductive materials on its surface,metal doping,controlling its morphology etc.In this paper,combined with the structure of lithium vanadium phosphate,we reviewed various modification methods and make a compara-tive analysis.Furthermore,combined with the research achievements of our team,the existing problems and the future research trend are discussed.