Consolidating Surface Lattice via Facile Self-Anchored Oxygen Layer Reconstruction Toward Superior Performance and High Safety Nickel-Rich Oxide Cathodes

Abstract

Nickel-rich oxide materials have been recognized as promising cathodes for state-of-art high energy lithium-ion batteries; however, challenges remain in their commercialization due to chemical and structural degradation, poor thermal stability related to oxygen lattice destabilization. Herein, this work reports a straightforward approach to stabilizing the surface oxygen framework by inducing surface reconstruction via swift proton exchange and heat treatment in argon atmosphere. The robust surface structure with localized disordered phase domains effectively suppresses interfacial parasitic reactions in highly delithiated cathodes and reduces detrimental phase degradation. Enabled by the strongly anchored oxygen framework, the consolidated surface lattice also reinforces cathode thermal stability featured by higher decomposition temperature and reduced oxygen release under thermal stress. In comparison to the unmodified counterpart, the reconstructed nickel-rich cathode demonstrates improved cycling stability and rate capability. This work reveals the critical role of regulating surface oxygen framework on the electrochemical performance and thermal behaviors, and explores the potential for feasible modification of nickel-rich cathodes for advanced lithium-ion batteries.