Decimal Solvent-Based High-Entropy Electrolyte Enabling the Extended Survival Temperature of Lithium-Ion Batteries to -130 degrees C

Freezing and crystallization of commercial ethylene carbonate-based binary electrolytes, leading to irreversible damage to lithium-ion batteries (LIBs), remain a significant challenge for the survival of energy storage devices at extremely low temperatures (<-40 degrees C). Herein, a decimal solvent-based high-entropy electrolyte is developed with an unprecedented low freezing point of -130 degrees C to significantly extend the service temperature range of LIBs, far superior to -30 degrees C of the commercial counterpart. Distinguished from conventional electrolytes, this molecularly disordered solvent mixture greatly suppresses the freezing crystallization of electrolytes, providing good protection for LIBs from possible mechanical damage at extremely low temperatures. Benefiting from this, our high-entropy electrolyte exhibits extraordinarily high ionic conductivity of 0.62 mS.cm(-1) at -60 degrees C, several orders of magnitude higher than the frozen commercial electrolytes. Impressively, LIBs utilizing decimal electrolytes can be charged and discharged even at an ultra-low temperature of -60 degrees C, maintaining high capacity retention (similar to 80% at -40 degrees C) as well as remarkable rate capability. This study provides design strategies of low-temperature electrolytes to extend the service temperature range of LIBs, creating a new avenue for improving the survival and operation of various energy storage systems under extreme environmental conditions.

Automated summary

A high-entropy electrolyte with a low freezing point of -130 degrees C has been developed to extend the temperature range of lithium-ion batteries, providing protection at extremely low temperatures and significantly improving ionic conductivity.