One-pot synthesis and multifunctional surface modification of lithium-rich manganese-based cathode for enhanced structural stability and low-temperature performance

High-energy-density lithium-rich Li1.2Ni0.13Co0.13Mn0.54O2 is regarded as one of the most promising cathode materials for lithium-ion batteries. However, its practical application is restricted by critical kinetics drawbacks and poor low-temperature electrochemical performances. In this research, Li1.2Ni0.13Co0.13Mn0.54O2 submicron particles coated by a Li7La3Zr2O12 (LLZO) layer and co-doped by La/Zr cations has been fabricated via a facile one-pot sol-gel technique and subsequent heat treatment. The coating LLZO layer with a few nanometers is able to build a rapid lithium-ion transport channel for adjacent particles and suppress severe side reactions between active material and the electrolyte. Moreover, large-radius La/Zr cations co-doping can broaden the diffusion paths of lithium ions, hinder the detrimental structural transformation, and improve the electrochemical structure stability of the cathode during repeated cycles. Owing to numerous merits from this multifunctional surface modification strategy, the modified Li1.2Ni0.13Co0.13Mn0.54O2 composite exhibits the significantly decreased interface impedance, enhanced Li+ diffusion kinetics and mitigated phase transformation, as well as excellent low-temperature electrochemical performance. It can contribute ultrahigh capacities of 173.8 mAh g-1 at -10 ℃ and 134.1 mAh g-1 at -20 ℃, respectively, displaying great application prospects of Li-rich cathode materials.