Manipulating Interfacial Stability via Preferential Absorption for Highly Stable and Safe 4.6 V LiCoO2 Cathode

• Published in: Nano-micro letters Vol. 17; no. 1; pp. 181 - 16
• Main Authors: Chen, Long, He, Xin, Chen, Yiqing, Hou, Youmin, Zhang, Yujie, Wang, Kangli, Ai, Xinping, Cao, Yuliang, Chen, Zhongxue
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.12.2025; Springer Nature B.V; SpringerOpen
• Subjects: 4.6 V LCO; Absorption; Cathodes; Defluorination; Design; Electrochemical analysis; Electrolyte design; Electrolytes; Electrolytic cells; Electrons; Energy; Energy levels; Engineering; High voltages; High-safe; Industrial applications; LiF-rich interface; Lithium compounds; Lithium fluoride; Lithium-ion batteries; Low temperature; Molecular orbitals; Nanoscale Science and Technology; Nanotechnology; Nanotechnology and Microengineering; Penetration; Phase transitions; Solvents; Wide-temperature; China; Japan; Electrolyte design; LiF-rich interface; 4.6 V LCO; High-safe; Wide-temperature
• ISSN: 2311-6706; 2150-5551; 2150-5551
• DOI: 10.1007/s40820-025-01694-4

Highlights A novel electrolyte design strategy for high voltage and high safe LiCoO 2 (LCO) cathode based on highest occupied molecular orbital and LCO absorption energy descriptor was proposed. The irreversible phase transformation was restricted by the LiF rich LCO/electrolyte interface. The well designed tris 2, 2, 2-trifluoroethyl phosphate electrolyte endows Ah grade Gr||LCO pouch cell with excellent electrochemical performance (85.3% capacity retention after 700 cycles), low-temperature adaptability (−60 °C retention: 53%) and greatly improved thermal safety (pass nail penetration). Elevating the upper cutoff voltage to 4.6 V could effectively increase the reversible capacity of LiCoO 2 (LCO) cathode, whereas the irreversible structural transition, unstable electrode/electrolyte interface and potentially induced safety hazards severely hinder its industrial application. Building a robust cathode/electrolyte interface film by electrolyte engineering is one of the efficient approaches to boost the performance of high-voltage LCO (HV-LCO); however, the elusive interfacial chemistry poses substantial challenges to the rational design of highly compatible electrolytes. Herein, we propose a novel electrolyte design strategy and screen proper solvents based on two factors: highest occupied molecular orbital energy level and LCO absorption energy. Tris (2, 2, 2-trifluoroethyl) phosphate is determined as the optimal solvent, whose low defluorination energy barrier significantly promotes the construction of LiF-rich cathode/electrolyte interface layer on the surface of LCO, thereby eventually suppresses the phase transition and enhances Li + diffusion kinetics. The rationally designed electrolyte endows graphite||HV-LCO pouch cells with long cycle life (85.3% capacity retention after 700 cycles), wide-temperature adaptability (− 60–80 °C) and high safety (pass nail penetration). This work provides new insights into the electrolyte screening and rational design to constructing stable interface for high-energy lithium-ion batteries.