Suppressing strain propagation in ultrahigh-Ni cathodes during fast charging via epitaxial entropy-assisted coating

• Published in: Nature energy 2024-03, Vol.9 (3), p.345-356
• Main Authors: Zhao, Chen, Wang, Chuanwei, Liu, Xiang, Hwang, Inhui, Li, Tianyi, Zhou, Xinwei, Diao, Jiecheng, Deng, Junjing, Qin, Yan, Yang, Zhenzhen, Wang, Guanyi, Xu, Wenqian, Sun, Chengjun, Wu, Longlong, Cha, Wonsuk, Robinson, Ian, Harder, Ross, Jiang, Yi, Bicer, Tekin, Li, Jun-Tao, Lu, Wenquan, Li, Luxi, Liu, Yuzi, Sun, Shi-Gang, Xu, Gui-Liang, Amine, Khalil
• Format: Article
• Language: English
• Subjects: 639/301/299/891; 639/638/161/891; Cathodes; Charging; Coating; Coatings; Corrosion prevention; Corrosion rate; Economics and Management; Energy; Energy Policy; Energy Storage; Energy Systems; Entropy; Epitaxy; Lattice strain; Propagation; Reconstruction; Renewable and Green Energy; Stability analysis; Structural stability; Synchrotron radiation; Temperature tolerance; Thermal stability; Tolerances; Ultrahigh temperature
• ISSN: 2058-7546; 2058-7546
• DOI: 10.1038/s41560-024-01465-2

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 x Co y Mn 1− x − y O 2 ( 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. Layered Ni-rich oxide cathodes are susceptible to challenges with surface reconstruction and strain propagation, limiting their cyclability. The authors propose a solution involving oriented attachment-driven reactions, utilizing Wadsley–Roth nanocrystals and layered oxide to induce an epitaxial entropy-assisted coating, effectively addressing these issues.