The 'winterproof' lithium-ion battery operates at -80 degrees Celsius

Chinese scientists develop a new electrolyte that allows lithium-ion batteries to charge and function well at extremely low temperatures .

Lithium-ion batteries dominate the current battery market mainly because they are very light compared to the amount of energy they store. This makes lithium-ion batteries extremely valuable for laptops, smartphones and even electric vehicles. However, the problem is that as the temperature drops, they charge more slowly and store less energy. The problem lies in the battery's electrolyte .

The new electrolyte could speed up charging and increase the operating temperature range for lithium-ion batteries. (Photo: Zhejiang University)

Professor Xiulin Fan's research group at Zhejiang University developed a new electrolyte that allows lithium-ion batteries to charge and operate at temperatures as low as -80 degrees Celsius , IFL Science reported on March 5. New research published in the journal Nature.

Current electrolytes can transport lithium ions and interact with graphite anodes at around 25 degrees Celsius, but both of these abilities decline as temperatures drop. High concentration electrolytes and some other alternatives do not freeze at the anode interface, but are more viscous and carry less charge, reducing efficiency under normal conditions.

Xiulin Fan's research team investigated the performance of a series of solvents and discovered three solvents with microscopic solvent molecules that can form Li+ transport channels that promote rapid ion movement. Two of these failed to meet the other basic requirements of a battery electrolyte, but the remaining solvent, fluoroacetonitrile, appeared to meet all the necessary criteria. The small solvent molecules in the electrolyte form two shells around the lithium ion, both of which are smaller and easier to transport than the layers in the dilute carbonate electrolyte.

The fluoroacetonitrile battery has excellent ionic conductivity at room temperature, and charges and discharges well in -80 degrees Celsius to 60 degrees Celsius. At -70 degrees Celsius, its performance beats some alternatives. substitution by a factor of about 10,000 times. The new battery maintains performance for more than 3,000 charge-discharge cycles at a temperature of 6 degrees Celsius. Fan said the battery can reach 80% of its capacity when charged for 10 minutes.

According to Fan's team, the new technology could be generalized and extended to other metal-ion battery electrolytes. This will benefit grid operators in cold regions that need to balance energy production during the winter.