Extending the low temperature operational limit of Li-ion battery to −80 °C

Achieving high performance during low-temperature operation of lithium-ion (Li+) batteries (LIBs) remains a great challenge. In this work, we choose an electrolyte with low binding energy between Li+ and solvent molecule, such as 1,3-dioxolane-based electrolyte, to extend the low temperature operational limit of LIB. Further, to compensate the reduced diffusion coefficient of the electrode material at ultralow temperature, nanoscale lithium titanate is used as electrode material, which finally, we demonstrate a LIB with unprecedented low-temperature performance, delivering ∼60% of its room-temperature capacity (0.1 °C rate) at −80 °C. Though insufficient ionic conductivity of the electrolyte is generally considered as the main reason for the poor low-temperature performance in LIBs, we found that the sluggish desolvation of solvated Li+ at the liquid-solid interface might be the critical factor. These findings provide evidence for the effective design of robust LIBs for ultralow temperature applications.