AUTHOR=Zhong Shengkui , Zhang Xiaoping , Liu Jiequn , Sui Yulei TITLE=Study on xLiVPO4F·yLi3V2(PO4)3/C Composite for High-Performance Cathode Material for Lithium-Ion Batteries JOURNAL=Frontiers in Chemistry VOLUME=8 YEAR=2020 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2020.00361 DOI=10.3389/fchem.2020.00361 ISSN=2296-2646 ABSTRACT=

Cathode materials made of xLiVPO4yLi3V2(PO4)3/C (x:y = 1:0, 2:1, 0:1) are synthesized via a feasible sol-gel method for high-performance lithium-ion batteries. The structures, morphology, and electrochemical properties of the composites are thoroughly investigated. The results show that LiVPO4F/C, Li3V2(PO4)3/C, and 2LiVPO4F·Li3V2(PO4)3/C can be synthesized under 750°C without the formation of impurities. Meanwhile, the unique morphology of the 2LiVPO4F·Li3V2(PO4)3/C composite, which is porous, with nanoflakes adhering to the surface, is revealed. This composite integrates the advantages of LiVPO4F and Li3V2(PO4)3. There are four discharge plateaus near 4.2, 4.1, 3.7, and 3.6 V, and the cathode material delivers high capacities of 143.4, 141.6, 133.2, 124.1, and 117.6 mAh g−1 at rates of 0.1, 0.2, 0.5, 1, and 2 C, respectively. More importantly, the discharge capacity can be almost fully recovered when the discharge rate returns to 0.1 C. The study is highly promising for the development of cathode material for LIBs.