Surface-engineering of layered LiNi0.815Co0.15Al0.035O2 cathode material for high-energy and stable Li-ion batteries

Surface engineering is an effective strategy to restrain the generation of rocksalt NiO phase on surface of layered LiNi0.815Co0.15Al0.035O2 (NCA) primary nanoparticles, a representative Ni-rich layered oxides cathode materials. Herein, we demonstrate the kilogram-scale synthesis of few-layer reduced graphene oxide (rGO) conformably coated NCA primary nanoparticles cathode materials by a mechanical wet ball-milling strategy. The lightening rGO coating layer effectively avoids the direct contact of electrolyte and NCA with rapid electrons transfer. As a result, the as-obtained NCA@rGO hybrids with only 1.0 wt% rGO content can deliver a high specific capacity (196 mAh g(-1) at 0.2 C) and fast charge/discharge capability (127 mAh g(-1) at 5 C), which is much higher than the corresponding NCA nanoparticles (95 mAh g(-1) at 5 C). Even after 100 cycles at 1 C, 91.7% of initial reversible capacity is still maintained. Furthermore, a prismatic pouch cell (240 mAh) is also successfully assembled with the commercial graphite anode. (C) 2017 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.