Cation/Anion Codoped and Cobalt-Free Li-Rich Layered Cathode for High-Performance Li-Ion Batteries
Lu Nie, Zeyu Wang, Xiaowen Zhao, Shaojie Chen, Yingjie He, Haojie Zhao, Tianyi Gao, Yue Zhang, Lei Dong, Franklin Kim, Yi Yu, Wei Liu
Abstract
Lithium-rich layered oxides have received great attention due to their high energy density as cathode material. However, the progressive structural transformation from layered to spinel phase triggered by transition-metal migration and the irreversible release of lattice oxygen leads to voltage fade and capacity decay. Here, we report a Fe, Cl codoped and Co-free Li-rich layered cathode with significantly improved structural stability. It is revealed that the Fe and Cl codoping can facilitate the Li-ion diffusion and improve the rate performance of the materials. Moreover, the calculations show that the structural stability is enhanced by Fe and Cl codoping. As a result, the Fe and Cl codopant reduces the irreversible release of lattice oxygen, mitigates voltage fade, and improves the first-cycle Coulombic efficiency. This work provides a low-cost, environmentally friendly, practical strategy for high-performance cathode materials.