China's Tech Mosaic: This lithium battery works at minus 50 degrees Celsius!

Editor's note: China is not one innovation story but many – emerging from local areas across the nation. In this series, we bring you those stories as pieces of a larger mosaic that, when put together, reveal the full picture of a country on the move.

Chinese researchers made a major breakthrough in high-energy lithium batteries, creating a new type of battery that works in temperatures as low as minus 50 degrees Celsius.

Currently, commercial lithium batteries use liquid electrolytes made of lithium salts and carbonate solvents, which typically stop working before minus 50 degrees Celsius.

A research team from Nankai University, located in east China's Tianjin Municipality, designed a new type of fluorinated hydrocarbon solvent molecule. By precisely controlling the electron density of fluorine atoms and the molecular structure, they found a way to effectively dissolve lithium salts in the electrolyte, replacing the traditional method.

After further optimization, the team established design principles for this new electrolyte and ensured its compatibility with lithium metal.

Compared to traditional electrolytes, this new version has better surface wetting and higher efficiency, so less material is needed. Also, because lithium binds more weakly to fluorine, it moves more freely even at extremely low temperatures, enabling fast charge transfer. This led to an ultra-high-energy lithium metal battery that delivers 700 watt-hours per kilogram at room temperature. Even at minus 50 degrees Celsius, the battery maintains nearly 400 Wh/kg.

This new technology could be used in electric vehicles, smart robots, low-altitude aviation, polar exploration and aerospace applications.

The research has been published in academic journal Nature.

Source: Tianjin International Communication Center. Sun Daxin is also an author of the story.