The search for cathode materials with high energy density, long-term cycling stability, and low cost is one of the most important challenges for current lithium-ion batteries. To address the structural instability in Mn-rich layered cathodes, we demonstrate herein through thorough experimental and theoretical studies that delocalizing Li@Mn₆ superstructure units within transition-metal layers is an effective strategy to enhance the layer stability of a Li-excess Mn-rich layered oxide (LMRO) cathode. The delocalized Li@Mn₆ superstructure units can not only increase the Mn valence to inhibit the adverse Jahn-Teller effect but also harness the anionic redox activity with suppressed O–Mn₀ species. Benefited from its stable layered structure, the LMRO cathode can retain a high capacity and energy density of 251 mA h g⁻¹ and 791 W h kg⁻¹, respectively, after 100 cycles with nearly 100% retention. This work provides a feasible route to develop the high-performance layered cathodes with stable anionic redox chemistry.

寻找具有高能量密度、长期循环稳定性和低成本的正极材料是当前锂离子电池面临的最重要挑战之一。为了解决富锰层状正极的结构不稳定性，我们通过彻底的实验和理论研究证明，在过渡金属层中离域 Li@Mn ₆超结构单元是提高锂过量 Mn- 层稳定性的有效策略。富层状氧化物（LMRO）阴极。离域的 Li@Mn ₆超结构单元不仅可以增加 Mn 化合价以抑制不利的 Jahn-Teller 效应，而且可以利用抑制 O-Mn _{0的阴离子氧化还原活性}物种。得益于其稳定的层状结构，LMRO 正极在 100 次循环后可以分别保持 251 mA hg ^-1和 791 W h kg ^-1的高容量和能量密度，且保持率接近 100%。这项工作为开发具有稳定阴离子氧化还原化学的高性能层状正极提供了一条可行的途径。