Li Plating Regulation on Fast‐Charging Graphite Anodes by a Triglyme‐LiNO3 Synergistic Electrolyte Additive

• Published in: Angewandte Chemie International Edition Vol. 62; no. 34; pp. e202306963 - n/a
• Main Authors: Xu, Xuejiao, Yue, Xinyang, Chen, Yuanmao, Liang, Zheng
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 21.08.2023
• Edition: International ed. in English
• Subjects: Anodes; Charging; Electrolytes; Fast Charging; Graphite; Ion flux; Lithium Dendrite; Lithium Plating; Lithium-Ion Batteries; Plating; Solid Electrolyte Interphase; Solid electrolytes
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202306963

Graphite anodes are prone to dangerous Li plating during fast charging, but the difficulty to identify the rate‐limiting step has made a challenging to eliminate Li plating thoroughly. Thus, the inherent thinking on inhibiting Li plating needs to be compromised. Herein, an elastic solid electrolyte interphase (SEI) with uniform Li‐ion flux is constructed on graphite anode by introducing a triglyme (G3)‐LiNO3 synergistic additive (GLN) to commercial carbonate electrolyte, for realizing a dendrite‐free and highly‐reversible Li plating under high rates. The cross‐linked oligomeric ether and Li3N particles derived from the GLN greatly improve the stability of the SEI before and after Li plating and facilitate the uniform Li deposition. When 51 % of lithiation capacity is contributed from Li plating, the graphite anode in the electrolyte with 5 vol.% GLN achieved an average 99.6 % Li plating reversibility over 100 cycles. In addition, the 1.2‐Ah LiFePO4 | graphite pouch cell with GLN‐added electrolyte stably operated over 150 cycles at 3 C, firmly demonstrating the promise of GLN in commercial Li‐ion batteries for fast‐charging applications. This paper proposes a strategy of Li plating regulation rather than Li plating inhibition. In this situation, Li plating on graphite has a dendrite‐free morphology and a high reversibility. By effectively utilizing Li plating instead of suppressing it, it is possible to achieve a compatible pathway for fast charging of graphite anodes.