posted on 2021-09-20, 17:04authored byLu Nie, Zeyu Wang, Xiaowen Zhao, Shaojie Chen, Yingjie He, Haojie Zhao, Tianyi Gao, Yue Zhang, Lei Dong, Franklin Kim, Yi Yu, Wei Liu
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.