Surface reconstruction and the associated severe strain propagation have long been reported as the major cause of cathode failure during fast charging and long-term cycling. Despite tremendous attempts, no known strategies can simultaneously address the electro-chemomechanical instability without sacrificing energy and power density. Here we report an epitaxial entropy-assisted coating strategy for ultrahigh-Ni LiNi_xCo_yMn_1−x−yO₂ (x ≥ 0.9) cathodes via an oriented attachment-driven reaction between Wadsley–Roth phase-based oxides and the layered-oxide cathodes. The high anti-cracking and anti-corrosion tolerances as well as the fast ionic transport of the entropy-assisted surface effectively improved the fast charging/discharging capability, wide temperature tolerance and thermal stability of the ultrahigh-Ni cathodes. Comprehensive analysis from the primary and secondary particle level to the electrode level using multi-scale in situ synchrotron X-ray probes reveals greatly reduced lattice dislocations, anisotropic lattice strain and oxygen release as well as improved bulk/local structural stability, even when charging beyond the threshold state of charge (75%) of layered cathodes.

长期以来，表面重建和相关的严重应变传播一直被认为是快速充电和长期循环期间阴极故障的主要原因。尽管进行了巨大的尝试，但没有已知的策略可以在不牺牲能量和功率密度的情况下同时解决电化学机械不稳定性。_{在这里，我们报告了一种用于超高Ni LiNi x} Co _y Mn _{1− x − y} O ₂ ( x ≥ 0.9)阴极的外延熵辅助涂层策略， 通过Wadsley-Roth相基氧化物和层状材料之间的定向附着驱动反应-氧化物阴极。熵辅助表面的高抗裂和耐腐蚀能力以及快速的离子传输能力有效提高了超高镍正极的快速充放电能力、宽温耐受性和热稳定性。使用多尺度原位同步加速器 X 射线探针对初级和次级粒子水平到电极水平进行综合分析，结果表明，即使在充电超过层状阴极的阈值充电状态（75%）。