Advanced Electrolytes for Fast‐Charging High‐Voltage Lithium‐Ion Batteries in Wide‐Temperature Range
Xianhui Zhang, Lianfeng Zou, Yaobin Xu, Xia Cao, Mark Engelhard, Bethany E. Matthews, Lirong Zhong, Haiping Wu, Hao Jia, Xiaodi Ren, Peiyuan Gao, Zonghai Chen, Yan Qin, Christopher Kompella, Bruce W. Arey, Jun Li, Deyu Wang, Chongmin Wang, Ji‐Guang Zhang, Wu Xu
Abstract
Abstract LiNi x Mn y Co 1− x − y O 2 (NMC) cathode materials with Ni ≥ 0.8 have attracted great interest for high energy‐density lithium‐ion batteries (LIBs) but their practical applications under high charge voltages (e.g., 4.4 V and above) still face significant challenges due to severe capacity fading by the unstable cathode/electrolyte interface. Here, an advanced electrolyte is developed that has a high oxidation potential over 4.9 V and enables NMC811‐based LIBs to achieve excellent cycling stability in 2.5–4.4 V at room temperature and 60 °C, good rate capabilities under fast charging and discharging up to 3C rate (1C = 2.8 mA cm −2 ), and superior low‐temperature discharge performance down to −30 °C with a capacity retention of 85.6% at C/5 rate. It is also demonstrated that the electrode/electrolyte interfaces, not the electrolyte conductivity and viscosity, govern the LIB performance. This work sheds light on a very promising strategy to develop new electrolytes for fast‐charging high‐energy LIBs in a wide‐temperature range.