Protection of Li metal anode by surface-coating of PVDF thin film to enhance the cycling performance of Li batteries

Lithium metal, the ideal anode material for next-generation high-energy batteries, suffers from the severe safety problem of Li dendrites. Herein, we report a simple approach to effectively maintain the morphology of Li-metal anode and enhance the cycling performance of Li batteries by surface coating of a porous polyvinylidene fluoride (PVDF) thin film. In symmetrical cells testing, the cells with the Li@PVDF electrode display stable cycling performance more than 1300 h (650 cycles) at the current density of 0.5 mA/cm(2) with a stripping/plating capacity of 0.5 mAh/cm(2). The results with full cells employing Li@PVDF anode and LiFePO4 cathode show a good cycling ability with a capacity retention of 80.0% after 500 cycles at 4 C and an excellent rate capability with a high capacity of 78.4 inA h/g even at a high rate of 10 C. (C) 2018 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.