Title: Flash joule heating-induced spinel-phase surface in Ni-rich layered oxide positive electrodes to stabilise lattice oxygen

Authors: Yang, Huiping; Sun, Zhefei; Zhao, Yonghui; Zhang, Ying; Sun, Zhiyi; Yi, Hongling; Wang, Huiqun; Mao, Yuxiang; Liu, Junjie; Chen, Wenxing; Wang, Jiexi; Feng, Shijie; Zhao, Qinghe; Cao, Yang; Han, Jiajia*; Zhang, Qiaobao*; Zhang, Li*

Abstract: High-nickel layered positive electrodes suffer from progressive structural degradation arising from lattice oxygen loss and inherent lattice strain. Although surface coatings are widely used to stabilize lattice-oxygen redox and mitigate electro-chemo-mechanical degradation, achieving coatings with full continuity, robust interfacial bonding, and fast Li + conductivity remains challenging. Herein, we present a fundamentally different approach to shell formation via a self-derived subtractive strategy, departing from the conventional additive-based coating methods. By accurately applying transient thermal pulses, surface lithium is selectively extracted from layered LiNi x Co y Mn 1- x - y O 2 ( x = 0.8 ~ 0.9), directly converting the outer region into a coherent spinel-phase shell with tunable thickness. This nanoscale spinel-phase skin forms a robust mortise-and-tenon-like interconnection with the layered bulk, enabling isotropic, high-rate Li + extraction/insertion while maintaining electronic conductivity throughout cycling. It effectively confines active oxygen intermediates, and suppresses interfacial side reactions and strain evolution under high-potential operation. Therefore, the spinel-phase skin-encapsulated LiNi 0.8 Co 0.1 Mn 0.1 O 2 achieves an initial Coulombic efficiency of 95.3% and enables pouch cells with 80.1% capacity retention after 2000 cycles at 180 mA g -1 . This strategy is extendable to LiNi 0.9 Co 0.05 Mn 0.05 O 2 , may open new avenues for advancing nickel-rich positive electrode technologies.

Full-Link: https://www.nature.com/articles/s41467-026-70616-8