Regulate the lattice oxygen activity and structural stability of lithium-rich layered oxides by integrated strategies

Lithium-rich layered oxides have attracted much attention due to a high discharge capacity (>250 mAh g⁻¹). However, the low rate capability associated with the intrinsic poor electronic conductivity, the irreversible capacity loss and voltage decay resulting from the lattice oxygen release during the initial cycle seriously limit its practical application. To overcome these problems, lithium-rich layered oxides self-assembled with exposed (0 1 0) plane are prepared, which facilitate Li⁺ intercalation/deintercalation and contribute to high rate capabilities. Besides, a co-modification strategy of W doping and in-situ interfacial induced preparation of layered@spinel@Li₂WO₄ structure is proposed. Tungsten ions in the lattice have strong covalent bonds with oxygen, which can stabilize the layered structure, inhibit irreversible lattice oxygen loss, suppress the capacity fade and voltage decay during the cycle. The spinel phase with unique three-dimensional structure and Li₂WO₄ with cubic tunnel structure can provide diffusion channels for Li-ions, which are conducive to accelerating the Li⁺ diffusion and improving the rate performances of the lithium-rich layered oxides. Our studies imply that W doping and layered@spinel@Li₂WO₄ co-modification structure can effectively regulate lattice oxygen activity, alleviate the side reactions and improve the structural stability of the Li-rich layered oxides. This work provides integrated strategies for regulating the irreversible lattice oxygen release and enhancing the electrochemical performance of lithium-rich layered oxides.