110th Anniversary: Concurrently Coating and Doping High-Valence Vanadium in Nickel-Rich Lithiated Oxides for High-Rate and Stable Lithium-Ion Batteries

Surface engineering and heteroelement doping are recognized as highly effective protocols to enhance nickel (Ni)-rich lithiated oxides. Herein, we report the kilogram-scale preparation of the concurrent coating and doping of high-valence vanadium (V) in Ni-rich LiNi0.815Co0.15Al0.035O2 (denoted as V-NCA) cathode materials. Hydrofluoric acid (HF) is greatly restricted by removing the residual lithium salts after the reaction with a vanadium source. In the subsequent low-temperature process, the coating of vanadium compounds (V2O5, Li3VO4) and the doping of V ions have been realized, which remarkably decreases the dissolution of active materials and the Li+/Ni2+ disorder. Consequently, the stable reversible specific capacity increases by 17.7% at 0.1 C (202.6 mAh g(-1)) and by 59.6% at 5 C (147 mAh g(-1)) compared with the pristine NCA. We also assembled a pouch cell of 650 mAh (3.33 g of V-NCA) by choosing graphite as the anode material, in which 89.2% capacity retention is achieved after 500 cycles at 1 C.