Bifunctional Localized High-Concentration Electrolyte for the Fast Kinetics of Lithium Batteries at Low Temperatures

Traditional lithium batteries cannot work well at lowtemperaturesdue to the sluggish desolvation process, which limits their applicationsin low-temperature fields. Among various previously reported approaches,solvation regulation of electrolytes is of great importance to overcomethis obstacle. In this work, a tetrahydrofuran (THF)-based localizedhigh-concentration electrolyte is reported, which possesses the advantagesof a unique solvation structure and improved mobility, enabling aLi/lithium manganate (LMO) battery to cycle stably at room temperature(retains 85.9% after 300 cycles) and to work at a high rate (retains69.0% at a 10C rate). Apart from that, this electrolyte demonstratessuperior low-temperature performance, delivering over 70% capacityat -70 & DEG;C and maintaining 72.5 mAh g(-1) (& AP;77.1%) capacity for 200 cycles at a 1C rate at -40 & DEG;C. Also, even when the rate increases to 5C, the battery couldstill operate well at -40 & DEG;C. This work demonstrates thatsolvation regulation has a significant impact on the kinetics of cellsat low temperatures and provides a design method for future electrolytedesign.