Raising the cut-off voltages is the easiest way to approach the theoretical specific capacity of LiCoO₂ (274 mAh g⁻¹). However, an elevated voltage can lead to severe structural degradation and side-reactions at the electrode/electrolyte interface, therefore the excellent electrochemical performance of LiCoO₂ is hardly achievable. Hereby, we adopt the gadolinium modification strategy to simultaneously enhance the structural and interfacial stability of LiCoO₂ cathode materials. Introducing gadolinium into the transition metal layers can suppress the layered structure collapse triggered by the irreversible phase transition. The interfacial stability is also significantly improved with the gadolinium oxide coating layer formed on the surface of LiCoO₂, which separates the cathode from the electrolyte. Therefore, the gadolinium-modified LiCoO₂ exhibits a capacity retention of 82.7% after 100 cycles at 3.0–4.6 V, 0.5C. Moreover, density functional theory (DFT) calculations demonstrate that the gadolinium modification of LiCoO₂ shortens the Co–O bond length to inhibit lattice oxygen release and reduce the Li⁺ migration barrier, thus exhibiting a capacity of 149.5 mAh g⁻¹ even at 8C. This research will provide novel insights into the structural and interfacial modification of the high-voltage LiCoO₂, making a meaningful contribution towards optimizing the electrochemical performance.

提高截止电压是接近LiCoO ₂的理论比容量（274 mAh g ^-1）的最简单方法。然而，升高的电压会导致电极/电解质界面的严重结构退化和副反应，因此难以实现LiCoO _{2的优异电化学性能。}因此，我们采用钆改性策略同时提高LiCoO ₂正极材料的结构和界面稳定性. 将钆引入过渡金属层可以抑制由不可逆相变引发的层状结构坍塌。_{LiCoO 2}表面上形成的氧化钆涂层也显着提高了界面稳定性，该涂层将阴极与电解质隔开。因此，钆改性的 LiCoO ₂在 3.0–4.6 V、0.5C 下 100 次循环后的容量保持率为 82.7%。此外，密度泛函理论 (DFT) 计算表明，LiCoO ₂的钆修饰缩短了 Co-O 键长，从而抑制了晶格氧的释放并降低了 Li ^{+迁移势垒，因此表现出 149.5 mAh g -1}的容量。即使在 8C。该研究将为高压LiCoO ₂的结构和界面改性提供新的见解，为优化电化学性能做出有意义的贡献。