Mingxuan Guo and Haibo Li*
Background:Owing to the excellent theoretical specific capacity and safety intercalation potential, Li3VO4¬ (LVO) has been proposed as anadvanced anode material for lithium ions batteries (LIBs). However, the LVO suffers from low electronic conductivity that limits its commercialization.
Objective: The reduced graphene oxide (rGO) is recommended to couple with micro-LVO particles aiming to enhance the conductivity of compositeelectrodes.
Method: The LVO@rGO compositeis synthesized by a facile hydrothermal method. The morphology, crystallinity, valance state and electrochemical behavior of LVO@rGO are characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical workstation, respectively. Further, the LIBs’ performance is explored by making a coins-type half-cell LIBs battery via battery system.
Results: The Li+ diffusion rate of the optimized LVO@rGO electrode is 7.67×10-23 cm2 s-1, which improves two orders of magnitudesof pure LVO electrode. As a result, the LVO@rGO anode delivers a reversible capacity of 190.1 mAh/g at 0.1 A/g after 100 cycles, which is even twice higher than that of pure LVO anode (90.6 mAh/g). Besides,it exhibitssuperior rate capability, i.e.a reversible capability of 285.0, 220.2, 158.7, 105.2 and 71.7 mAh/g at 0.05, 0.1, 0.2, 0.5 and 1.0 A/g, respectively.
Conclusion: The high conductivity and flexible texture enable rGO an idea building block to enhance the Li ion diffusion of whole electrode. On the other hand, it is instrumental in alleviating the aggregation of host materials, leading to high specific surface and specific capacity.
Lithium-ion battery, Li3VO4, Graphene, Li ion diffusion, Hydrothermal, Electrochemistry
Ningxia Key Laboratory of Photovoltaic Materials, Ningxia University,Yinchuan, Ningxia, Ningxia Key Laboratory of Photovoltaic Materials, Ningxia University,Yinchuan, Ningxia