Reversible Monoclinic Transition Buffering and Stepwise Uniform Delithiation in Ni‐Rich Layered Cathodes
Abstract
Abstract Ultrahigh‐Ni layered oxides are promising high‐energy cathodes but suffer from severe structural degradation during cycling, particularly due to irreversible phase transitions and interfacial instability. While extensive studies focus on the hexagonal (H) phase transition, the intermediate monoclinic (M) phase plays a critical yet overlooked role in mediating lattice strain and enabling ordered delithiation. Stabilizing the M phase remains challenging in ultrahigh‐Ni cathodes due to linked bulk and surface degradation. Herein, we report stabilization of LiNiO 2 by combining Zr doping and Li 3 NbO 4 coating, which respectively suppresses anisotropic lattice distortion by forming Li/Ni superlattices and provides uniform protection on primary particles. This dual‐modification effectively inhibits NiO 6 bond length/angle dispersion within M phase, mitigating Jahn–Teller activity and establishing a reversible transition buffer that accommodates lattice strain and guides moderated M↔H conversion, thereby functioning as a structural bridge to ensure continuous symmetry recovery. The modified cathode achieves a stepwise uniform delithiation with layer‐by‐layer Li distribution, preventing separation into Li‐sufficient and Li‐deficient areas and delivering enhanced cycling stability with reduced voltage decay. This work demonstrates that M phase engineering is a promising strategy for developing ultrahigh‐Ni cathodes with high energy density and prolonged stability.
Article Details
Authors (11)
Zhichen Hou
State Key Laboratory of Advanced Chemical Power Sources, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Engineering Research Center of High-efficiency Energy Storage (Ministry of Education), Frontiers Science Center for New Organic Matter (Ministry of Education), College of Chemistry
Wanying Wang
College of Electronic Information and Optical Engineering
Fanqi Kong
State Key Laboratory of Advanced Chemical Power Sources, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Engineering Research Center of High-efficiency Energy Storage (Ministry of Education), Frontiers Science Center for New Organic Matter (Ministry of Education), College of Chemistry
Meng Yao
State Key Laboratory of Advanced Chemical Power Sources, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Engineering Research Center of High-efficiency Energy Storage (Ministry of Education), Frontiers Science Center for New Organic Matter (Ministry of Education), College of Chemistry
Yiyang Peng
Beijing National Laboratory for Molecular Science, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering
Kuiming Liu
State Key Laboratory of Advanced Chemical Power Sources, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Engineering Research Center of High-efficiency Energy Storage (Ministry of Education), Frontiers Science Center for New Organic Matter (Ministry of Education), College of Chemistry
Chen Li
Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA.
Zhaoyang Gao
State Key Laboratory of Advanced Power Sources Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) Engineering Research Center of High‐efficiency Energy Storage (Ministry of Education), College of Chemistry Tianjin 300071 China
Meng Yu
State Key Laboratory of Advanced Chemical Power Sources, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Engineering Research Center of High-efficiency Energy Storage (Ministry of Education), Frontiers Science Center for New Organic Matter (Ministry of Education), College of Chemistry
Weichao Wang
College of Electronic Information and Optical Engineering
Fangyi Cheng
State Key Laboratory of Advanced Chemical Power Sources, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Engineering Research Center of High-efficiency Energy Storage (Ministry of Education), Frontiers Science Center for New Organic Matter (Ministry of Education), College of Chemistry