Highly enhanced electrochemical performances of LiNi0.815Co0.15Al0.035O2 by coating via conductively LiTiO2 for lithium-ion batteries

LiTiO2 film-coated layered LiNi0.815Co0.15Al0.035O2 (NCA) material was successfully synthesised through in situ hydrolysis–lithiation to improve electrochemical properties. Herein, NCA was synthesised using solid state reaction, coated by hydrolysis of tetrabutyl titanate and subjected to lithiation process. The optimal molar ratio (LiTiO2: NCA) was found to be 1.0 mol%, and the thickness of LiTiO2 film coated on the surface of NCA of 18 nm was observed through HRTEM images. Compared with pristine NCA, 1.0 mol% LiTiO2-coated NCA demonstrated better electrochemical performance with larger capacity of 20 mAh g−1 under 1 C after 100 cycles. Its related capacity retention was 90.8%. The 1.0 mol% LiTiO2-coated sample exhibited high discharge capacity of 157.6 mAh g−1 at a current rate of 10 C, whereas the pristine sample only presented 145.3 mAh g−1. The considerably improvement of the rate and cycling properties of the NCA cathode material is achieved using LiTiO2 as a Li+-conductive coating layer. These new findings contribute towards the design of a stable-structured Ni-rich material for lithium-ion batteries.