Fire-extinguishing, recyclable liquefied gas electrolytes for temperature-resilient lithium-metal batteries

• Published in: Nature energy 2022-06, Vol.7 (6), p.548-559
• Main Authors: Yin, Yijie, Yang, Yangyuchen, Cheng, Diyi, Mayer, Matthew, Holoubek, John, Li, Weikang, Raghavendran, Ganesh, Liu, Alex, Lu, Bingyu, Davies, Daniel M., Chen, Zheng, Borodin, Oleg, Meng, Y. Shirley
• Format: Article
• Language: English
• Subjects: 639/301/299; 639/4077/4079/891; 639/638/161; Cycles; Economics and Management; Electrochemical analysis; Electrochemistry; Electrolytes; Energy; Energy Policy; Energy Storage; Energy Systems; Extinguishing; Fluorine; Ion currents; Liquefied gases; Lithium; Lithium batteries; Metals; Pentafluoroethane; Recyclability; Renewable and Green Energy; Resilience; Solvation; Storage batteries; Sustainability; Tetrafluoroethane; Vapor pressure
• ISSN: 2058-7546; 2058-7546
• DOI: 10.1038/s41560-022-01051-4

High-energy density, improved safety, temperature resilience and sustainability are desirable properties for lithium-battery electrolytes, yet these metrics are rarely achieved simultaneously. Inspired by the compositions of clean fire-extinguishing agents, we demonstrate inherently safe liquefied gas electrolytes based on 1,1,1,2-tetrafluoroethane and pentafluoroethane that maintain >3 mS cm −1 ionic conductivity from −78 to +80 °C. As a result of beneficial solvation chemistry and a fluorine-rich environment, lithium cycling at >99% Coulombic efficiency for over 200 cycles at 3 mA cm −2 and 3 mAh cm −2 was demonstrated in addition to stable cycling of Li/NMC622 full batteries from −60 to +55 °C. In addition, we demonstrate a one-step solvent-recycling process based on the vapour pressure difference at different temperatures of the liquefied gas electrolytes, which promises sustainable operation at scale. This work provides a route to sustainable, temperature-resilient lithium-metal batteries with fire-extinguishing properties that maintain state-of-the-art electrochemical performance. Lithium-metal batteries offer much promise for high-energy storage but their operation under extreme temperatures is challenging. Here the authors report a temperature-resilient high-performance lithium-metal battery based on a liquefied gas electrolyte that also has promising properties in safety and recyclability.