G.R. Wang, A.P. Zhang, X.X. Ren, M.Z. Yang, Y.N. Han and Z.-S. Wu *

Energy Storage Science and Technology, 2025, accepted.

For promoting the further development of high-end portable electronic products, it is an urgent need to develop lithium-ion batteries (LIBs) with high energy density, long cycle life, high power density, and wide operating temperature range. As the most successful cathode material in portable scenarios, lithium cobalt oxide (LiCoO2, LCO) still faces the key challenges of limited charging cut-off voltage, low specific capacity, unsatisfied fast charging capability and wide-temperature-range performance. Herein, we systematically summarize and discuss the failure mechanisms and key challenges of high-voltage LCO cathode, overview the latest research progress of various modification strategies, and propose a detailed perspective on development directions for future researches. Firstly, the key failure mechanisms of high-voltage LCO are comprehensively reviewed, including basic crystal and band structure, bulk structure failure process (e.g., complicated phase transition, irreversible interlayer slip, detrimental crack initiation and propagation), interface failure process (e.g., cobalt migration and dissolution, oxygen release, electrolyte catalytic decomposition, HF attack and cathode-electrolyte interphase degradation), and failure mechanisms under complex working conditions (e.g., high-voltage and fast charging, high-voltage, and high-temperature). Subsequently, we overview the representative modification strategies and mechanisms, including the improvement of lithium-ion diffusivity and bulk-phase stability through bulk elements doping, e.g., lithium site, cobalt site, oxygen site and multi-site doping; the enhancement of structural stability and ionic/electronic conductivity of the surface-interface through chemical manipulation, e.g., including surface coating (e.g., ionic conductors, electronic conductors, ionic/electronic insulator materials), in-situ surface-interface structural conversion through wet-chemical and thermo-chemical methods, electrolyte manipulation through modified additives, and in-situ electrochemical surface-interface conversion process; the optimization of ions/electrons transportation in the electrode through strategies of improving adhesives, conductive agents, and electrode structures. Finally, we elaborate on the forward-looking views on the future research direction of high-voltage LCO cathode, including (i) the structural design of high-voltage LCO (> 4.6 V); (ii) the design and control of the high-voltage (>4.6 V) LCO-electrolyte interface; (iii) preparation of LCO for high-voltage fast charging (>4.6 V, > 50 C) and high-voltage wide operating temperature range (>4.6 V, -60 °C ~ 70 °C); (iv) the optimization mechanism of modified LCO explained by advanced in-situ characterization and simulation; and (v) system design and cell construction of high-specific energy fast charging and high-specific energy wide temperature batteries. Overall, this review provides comprehensive and detailed suggestions and theoretical guidance for the design and fabrication of high-voltage LCO cathodes and other layered cathode materials for next-generation LIBs.