Controllable construction of La2Li0.5Co0.5O4 multifunctional armor to stabilize Li-rich layered oxide cathode for high-performance lithium-ion batteries

Lithium-rich manganese-based cathodes (LR) are valuable cathode materials for the next generation of lithium-ion batteries (LIBs) with high-energy density. However, the fast voltage/capacity decay on cycling is the major obstacle for the practical application induced by the less-than-ideal anionic redox reactions and structure distortion. Herein, in order to tackle these challenges, a perovskite-like La2Li0.5Co0.5O4 (LLCO) material is selected as protective surface to stabilize the Li1.2Mn0.54Ni0.13Co0.13O2 (LR) substrate through wet chemical coating method. Versatile structure/phase characterizations and electrochemical tests exhibit that the LLCO can not only minish the oxygen evolution and enhance the structure stability, but also restrain the electrolyte corrosion and increase the mechanical strength of cathode materials. Moreover, the coated LLCO with high electronic/ionic conductivity dramatically accelerates the energy storage kinetic, thereby displaying the improved rate performance. Specifically, the optimized LR@LLCO sample (1LLCO) exhibits a high capacity of 250.6 mAh.g(-1) after 100 cycles at 0.1 C and excellent capacity retention of 82.6% after 200 cycles at 2 C. This work provides a new idea for the modification of LR cathodes toward commercial high-performance LIBs.

Automated summary

In this study, a perovskite-like La2Li0.5Co0.5O4 (LLCO) material was selected as a protective surface to stabilize the Li1.2Mn0.54Ni0.13Co0.13O2 (LR) substrate through wet chemical coating method, effectively addressing the fast voltage/capacity decay of LR cathodes. LLCO can reduce oxygen evolution and enhance structure stability, while also preventing electrolyte corrosion and increasing the mechanical strength of cathode materials. Furthermore, the coated LLCO with high electronic/ionic conductivity significantly improves energy storage kinetics and rate performance of the batteries.