▎ 摘　　要

Surface engineering of battery-electrode materials is one of the hottest topics in both academic research and industry application fields. Up to now, however, there is still lack of a widely applicable strategy to achieve this goal. Herein, we demonstrate a universal method to accomplish electrode surface engineering via graphene oxide (GO) by spraying technology. In our study, a reduced graphene (rGO) layer can be fabricated on the surface of Li metal through the redox reaction of Li metal and GO. Notably, the protective layer on Li-metal anode can be capable of inhibiting the growth of Li dendrite and the symmetrical Li-rGO-Li cell can maintain 500 cycles without short circuits. What is pleasantly surprised, the GO layer can be uniformly coated on the surface of cathode (eg. LiNi0.6Co0.2Mn0.2O2 or NCM). Thanks to the simultaneous improvement of the anode and cathode, the NCM-GO-Li battery exhibits superb long-term cycles and excellent rate capability at high temperature of 60 degrees C.