An enhancement of electrochemical performance in lithium-ion battery via tantalum oxide coated nickel-rich cathode materials

Abstract

Abstract Nickel-rich cathode materials are increasingly being applied in commercial lithium-ion batteries to realize higher specific capacity as well as improve energy density. However, low structural stability and rapid capacity decay at high voltage and temperature hinder their rapid large-scale application. Herein, a wet chemical method followed by a post-annealing process is utilized to realize the surface coating of tantalum oxide on LiNi0.88Mn0.03Co0.09O2, and the electrochemical performance is improved. The modified LiNi0.88Mn0.03Co0.09O2 displays an initial discharge capacity of ~233 mAh/g at 0.1 C and 174 mAh/g at 1 C after 150 cycles in the voltage range of 3.0-4.4 V at 45 ℃, and it also exhibits an enhanced rate capability with 118 mAh/g at 5 C. The excellent performance is due to the introduction of tantalum oxide as a stable and functional layer to protect the surface of LiNi0.88Mn0.03Co0.09O2, and the surface side reactions and cation mixing are suppressed at the same time without hampering the charge transfer kinetics.