A cation and anion dual-doping strategy in novel Li-rich Mn-based cathode materials for high-performance Li metal batteries

Lithium (Li)-rich Manganese (Mn)-based cathode materials are considered to be the most hopeful cathode materials for next-generation high-energy-density Li metal batteries. However, the rapid capacity fading and voltage decaying derived from phase transformation still hinder their practical application. Herein, we developed a cation/anion dual-doping strategy by synchronically incorporating Zr4+ cation and F- anion to boost the structural stability of the Li-rich Mn-based cathode. The strengthened transition metal-oxygen bonds raised by doping effect can inhibit the release of oxygen for enhanced electrochemical reversibility and mitigate the anisotropic lattice distortion to stabilize the layered structure. Meanwhile, dual doping strategy expands the lattice distance and increases oxygen vacancy formation energy, thereby improving ion diffusion kinetics and structural stability. As a result, the obtained cathode presents an excellent initial discharge capacity of 268.5 mAh g-1 and a prolonged cycle lifespan beyond 300 cycles. A stable cycling performance can be obtained under a high areal capacity of 5.17 mAh cm-2 with a low negative/positive electrode capacity ratio of 1.93. Our dualdoping strategy provides a valuable new idea for improving the structural stability and electrochemical properties of Li-rich Mn-based cathode materials, further promoting the development of high-energy-density Li metal batteries.