Boosting the rate and cycling performance of β-LixV2O5 nanorods for Li ion battery by electrode surface decoration

Abstract

The β-phase lithium vanadium oxide bronze (β-LixV2O5) with high theoretic specific capacity up to 440 mAh g−1 is considered as promising cathode materials, however, their practical application is hindered by its poor ionic and electronic conductivity, resulting in unsatisfied cyclic stability and rate capability. Herein, we report the surface decoration of β-LixV2O5 cathode using both reduced oxide graphene (rGO) and ionic conductor LaPO4, which significantly promotes the electronic transfer and Li+ diffusion rate, respectively. As a result, the rGO/LaPO4/LixV2O5 composite exhibits excellent electrochemical performance in terms of high reversible specific capacity of 275.7 mAh g−1 with high capacity retention of 84.1% after 100 cycles at a current density of 60 mA g−1, and acceptable specific capacity of 170.3 mAh g−1 at high current density of 400 mA g−1. The cycled electrode is also analyzed by electrochemical impedance spectroscopy, ex-situ X-ray diffraction and scanning electron microscope, providing further insights into the improvement of electrochemical performance. Our work provides an effective approach to boost the electrochemical properties of lithium vanadates for practical application in lithium ion batteries.