The sensitive surface of nickel‐rich layered oxides often suffers from the erosion of CO₂ and H₂O in air. The results of erosion, including formation of impurities such as Li₂CO₃ and LiOH, degradation of layered structures and disproportionation of trivalent nickel, would cause cation mixing and structural instability. In order to overcome these inherent drawbacks, we present a targeted solvothermal followed by re‐oxidation approach to restore the structural stability and electrochemical performances of degraded Ni‐rich layered cathode materials. Owing to this unique approach, the resultant LiNi_0.8Co_0.15Al_0.05O₂ (NCA) demonstrate improved layered structure, a stable nanoscale coating shell and enhanced surface stability. The revived NCA enables higher reversible capacity and longer cycle life than that of degraded NCA. Specifically, the restored NCA can retain 82 % initial capacity after 200 cycles under 1 C at room temperature, and 87 % and 55 % initial capacity after 100 and 500 cycles under 1 C at 55 °C, respectively. This approach could be applied to improve the structural stability and electrochemical properties of degraded Ni‐rich layered oxides and suggests great potential in industrial applications.

中文翻译：

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恢复长寿命锂离子电池中降解的富镍正极材料

富镍层状氧化物的敏感表面经常遭受空气中CO ₂和H ₂ O的侵蚀。腐蚀的结果，包括形成杂质（如Li ₂ CO ₃和LiOH），层状结构的降解和三价镍的歧化，将导致阳离子混合和结构不稳定。为了克服这些固有的缺点，我们提出了一种目标溶剂热然后再氧化的方法，以恢复降解的富镍层状阴极材料的结构稳定性和电化学性能。由于这种独特的方法，所得的LiNi _0.8 Co _0.15 Al _0.05 O ₂（NCA）证明了改进的分层结构，稳定的纳米级涂层外壳和增强的表面稳定性。与退化的NCA相比，恢复的NCA具有更高的可逆容量和更长的循环寿命。具体而言，恢复的NCA在室温1 C下200个循环后可以保持82％的初始容量，在55°C下1 C下100和500个循环后可以分别保留87％和55％的初始容量。该方法可用于改善降解的富镍层状氧化物的结构稳定性和电化学性能，并在工业应用中显示出巨大的潜力。