Improving cyclability of Li metal batteries at elevated temperatures and its origin revealed by cryo-electron microscopy
Operations of lithium-ion batteries have long been limited to a narrow temperature range close to room temperature. At elevated temperatures, cycling degradation speeds up due to enhanced side reactions, especially when high-reactivity lithium metal is used as the anode. In this work, we demonstrate enhanced performance in lithium metal batteries operated at elevated temperatures. In an ether-based electrolyte at 60 °C, an average Coulombic efficiency of 99.3% is obtained and more than 300 stable cycles are realized, but, at 20 °C, the Coulombic efficiency drops dramatically within 75 cycles, corresponding to an average Coulombic efficiency of 90.2%. Cryo-electron microscopy reveals a drastically different solid electrolyte interface nanostructure emerging at 60 °C, which maintains mechanical stability, inhibits continuous side reactions and guarantees good cycling stability and low electrochemical impedance. Additionally, larger lithium particles grown at the elevated temperature reduce the electrolyte/electrode interfacial area, which decreases the per-cycle lithium loss and enables higher Coulombic efficiencies.
- Research Organization:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)
- Grant/Contract Number:
- AC02-76SF00515
- OSTI ID:
- 1560653
- Journal Information:
- Nature Energy, Vol. 4, Issue 8; ISSN 2058-7546
- Publisher:
- Nature Publishing GroupCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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