A high capacity cathode is the key to the realization of high‐energy‐density lithium‐ion batteries. The anionic oxygen redox induced by activation of the Li₂MnO₃ domain has previously afforded an O3‐type layered Li‐rich material used as the cathode for lithium‐ion batteries with a notably high capacity of 250–300 mAh g⁻¹. However, its practical application in lithium‐ion batteries has been limited due to electrodes made from this material suffering severe voltage fading and capacity decay during cycling. Here, it is shown that an O2‐type Li‐rich material with a single‐layer Li₂MnO₃ superstructure can deliver an extraordinary reversible capacity of 400 mAh g⁻¹ (energy density: ≈1360 Wh kg⁻¹). The activation of a single‐layer Li₂MnO₃ enables stable anionic oxygen redox reactions and leads to a highly reversible charge–discharge cycle. Understanding the high performance will further the development of high‐capacity cathode materials that utilize anionic oxygen redox processes.

中文翻译：

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具有单层Li2MnO3上层结构的高容量O2型富Li阴极材料

高容量阴极是实现高能量密度锂离子电池的关键。通过激活Li ₂ MnO ₃域诱导的阴离子氧还原，以前已经提供了一种O3型层状富Li材料，用作锂离子电池的阴极，具有250-300 mAh g ^-1的高容量。但是，由于这种材料制成的电极在循环过程中会遭受严重的电压衰减和容量衰减，因此其在锂离子电池中的实际应用受到了限制。在此表明，具有单层Li ₂ MnO ₃上层结构的O2型富Li材料可以提供400 mAh g ^-1的超强可逆容量。（能量密度：≈1360Wh kg ^-1）。单层Li ₂ MnO ₃的活化可实现稳定的阴离子氧还原反应，并导致高度可逆的充放电循环。了解高性能将进一步发展利用阴离子氧还原工艺的高容量阴极材料。