Enhancing interfacial stability of high-voltage LiCoO2 via fabricating a front-face with confined channels for desolvation.

Abstract

Lithium cobalt oxide (LiCoO2, LCO) is one of the most successful cathodes. However, it suffers from severe structural degradation and rapid capacity fading at high voltage (>4.5 V vs. Li+/Li). To improve high-voltage stability, researchers employ channel-type materials to desolvate lithium ions, resulting in a localized high-concentration environment. However, current channel-type materials, whether deployed as separators or additives, are hard to achieve effective desolvation of the electrolyte. Herein, we employ a facile and scalable high-speed solid-phase mechanofusion technique to construct a continuous and uniform zeolite coating layer on LCO (Zeolite@LCO). This inorganic zeolite layer physically decouples the Li+ desolvation process from the electric-field-driven intercalation. Enabled by the complete Li+ desolvation within the confined zeolite channels, a locally supersaturated electrolyte forms on the cathode surface, inherently suppressing the oxidative dehydrogenation of solvent molecules. Synergizing the confined channel effect with the intrinsic thermal robustness of the zeolite framework, this strategy comprehensively enhances the interfacial stability, thermal safety, and electrochemical performance of the Zeolite@LCO cathode. Consequently, Zeolite@LCO delivers an exceptional capacity retention of ∼83.0% after 300 cycles at a high cut-off voltage of 4.8 V. This confined channel interface design provides a highly translatable paradigm for developing high-energy-density cathodes innext-generation lithium-ion batteries.