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Regulating Surface and Grain‐Boundary Structures of Ni‐Rich Layered Cathodes for Ultrahigh Cycle Stability
Author(s) -
Cheng Xu,
Liu Meng,
Yin Jingyun,
Ma Chuansheng,
Dai Yanzhu,
Wang Deyu,
Mi Shaobo,
Qiang Wenjiang,
Huang Bingxin,
Chen Yanan
Publication year - 2020
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201906433
Subject(s) - materials science , coprecipitation , cathode , grain boundary , surface modification , sintering , phase (matter) , chemical engineering , grain growth , grain size , microstructure , metallurgy , mineralogy , nanotechnology , chemistry , organic chemistry , engineering
The wide applications of Ni‐rich LiNi 1‐ x‐y Co x Mn y O 2 cathodes are severely limited by capacity fading and voltage fading during the cycling process resulting from the pulverization of particles, interfacial side reactions, and phase transformation. The canonical surface modification approach can improve the stability to a certain extent; however, it fails to resolve the key bottlenecks. The preparation of Li(Ni 0.4 Co 0.2 Mn 0.4 ) 1‐ x Ti x O 2 on the surface of LiNi 0.8 Co 0.1 Mn 0.1 O 2 particles with a coprecipitation method is reported. After sintering, Ti diffuses into the interior and mainly distributes along surface and grain boundaries. A strong surface and grain boundary strengthening are simultaneously achieved. The pristine particles are fully pulverized into first particles due to mechanical instability and high strains, which results in serious capacity fading. In contrast, the strong surface and the grain boundary strengthening can maintain the structural integrity, and therefore significantly improve the cycle stability. A general and simple strategy for the design of high‐performance Ni‐rich LiNi 1‐ x ‐ y Co x Mn y O 2 cathode is provided and is applicable to surface modification and grain‐boundary regulation of other advanced cathodes for batteries.