Enhancing Li+ Transport in NMC811||Graphite Lithium‐Ion Batteries at Low Temperatures by Using Low‐Polarity‐Solvent Electrolytes

• Published in: Angewandte Chemie (International ed.) Vol. 61; no. 35; pp. e202205967 - n/a
• Main Authors: Nan, Bo, Chen, Long, Rodrigo, Nuwanthi D., Borodin, Oleg, Piao, Nan, Xia, Jiale, Pollard, Travis, Hou, Singyuk, Zhang, Jiaxun, Ji, Xiao, Xu, Jijian, Zhang, Xiyue, Ma, Lin, He, Xinzi, Liu, Sufu, Wan, Hongli, Hu, Enyuan, Zhang, Weiran, Xu, Kang, Yang, Xiao‐Qing, Lucht, Brett, Wang, Chunsheng
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 26.08.2022; Wiley
• Edition: International ed. in English
• Subjects: Charge transfer; Electrolytes; Electrolytic cells; ENERGY STORAGE; Graphite; Inorganic-Rich EEIs; Li-Plating Free; Lithium; Lithium-ion batteries; Low temperature; Low-Temperature Electrolyte; NMC811llGraphite; NMC811||Graphite; Polarity; Solvents; Weak Ion-Dipole Interactions
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202205967

LiNixCoyMnzO2 (x+y+z=1)||graphite lithium‐ion battery (LIB) chemistry promises practical applications. However, its low‐temperature (≤ −20 °C) performance is poor because the increased resistance encountered by Li+ transport in and across the bulk electrolytes and the electrolyte/electrode interphases induces capacity loss and battery failures. Though tremendous efforts have been made, there is still no effective way to reduce the charge transfer resistance (Rct) which dominates low‐temperature LIBs performance. Herein, we propose a strategy of using low‐polarity‐solvent electrolytes which have weak interactions between the solvents and the Li+ to reduce Rct, achieving facile Li+ transport at sub‐zero temperatures. The exemplary electrolyte enables LiNi0.8Mn0.1Co0.1O2||graphite cells to deliver a capacity of ≈113 mAh g−1 (98 % full‐cell capacity) at 25 °C and to remain 82 % of their room‐temperature capacity at −20 °C without lithium plating at 1/3C. They also retain 84 % of their capacity at −30 °C and 78 % of their capacity at −40 °C and show stable cycling at 50 °C. Low‐polarity‐solvent electrolytes (LPSEs) 1) enable the formation of the anion‐derived interphases on both electrodes and 2) have weak interactions between the solvent molecules and Li+, which provide fast Li+ transport kinetics and reduced resistance in both charge transfer process and Li+ transport in electrode/electrolyte interphases, achieving excellent battery performance under both fast‐charge and low‐temperature conditions.