A nanorod-like Ni-rich layered cathode with enhanced Li+ diffusion pathways for high-performance lithium-ion batteries

摘要

Ni-rich LiNixCoyMn1-x-yO2 (x >= 0.6) layered oxide cathodes are among the most promising cathode materials for lithium-ion batteries (LIBs) owing to their superior capacity, prominent energy density and low cost. However, the large volume change caused by phase transition and poor diffusion kinetics limits their application. Herein, a nanorod-like Ni-rich layered LiNi0.6Co0.2Mn0.2O2 cathode is synthesized via a facile surfactant-free co-precipitation route. Due to the unique nanorod morphology, more {010} electrochemically active planes are exposed. As a result, structural stability and diffusion kinetics are greatly improved. In terms of performance, it exhibits outstanding structural stability (the volume change is as small as 2.12% in the processes of charging and discharging) and rate performance (achieving a high discharge capacity of 152.2 mA h g(-1) at 5C). Such rationally designed cathode could meet the high high-energy requirements of next generation LIBs.