Enhanced electrochemical performance of LiVPO4F/f-graphene composite electrode prepared via ionothermal process

In this article, we report the synthesis of 1,2-dimethyl-3-(3-hydroxypropyl) imidazolium dicyanamide ionic liquid and its used as a reaction medium for low-temperature synthesis of triclinic LiVPO4F electrode material. Structural and morphological features of LiVPO4F were characterized using X-ray diffraction and scanning electron microscopy techniques. The electrochemical studies have been investigated using cyclic voltammetry, galvanostatic charge/discharge studies, and electrochemical impedance spectroscopic techniques. The ionothermally obtained LiVPO4F is modified to LiVPO4F/f-graphene composite electrode to obtain high specific capacity, better rate performance, and longer cycle life. Even after 250 cycles, the LiVPO4F/f-graphene composite electrode exhibited a specific capacity more than 84 % with good reversible de-intercalation/intercalation of Li-ions. This article also provides the comparative electrochemical performances of LiVPO4F/f-graphene composite, LiVPO4F/carbon, and LiVPO4F/graphene composite electrodes in a nonaqueous rechargeable Li-ion battery system.