(Invited) Exploiting New Electrolytes and Mechanistic Solvation Kinetics for Extreme Low Temperature Batteries

Abstract

Improving the extremely low temperature operation of rechargeable batteries is vital to the operation of electronics in extreme environments, where systems capable of high-rate discharge are in short supply. Herein, we demonstrate the holistic design of dual-graphite batteries, which circumvent the sluggish ion desolvation process found in typical lithium-ion batteries during discharge. These batteries were enabled by a novel electrolyte, which simultaneously provided high electrochemical stability and ionic conductivity at low temperature. The dual-graphite cells, when compared to industry-type graphite || LiCoO2 full-cells demonstrated an 11 times increased capacity retention at -60 oC for a 10 C discharge rate, indicative of the superior kinetics of the “dual-ion” storage mechanism. These trends are further supported by GITT and EIS measurements at reduced temperature. This work provides a new design strategy for extreme low-temperature batteries. In addition, the electrolytes developed for dual-ion cells have also been extended to search for other high-capacity, high-rate electrodes, which leads to further improved energy density and stability for both high and extremely low temperatures.