A polymer-based battery chemistry could enable electric vehicles (EVs) to keep working in freezing conditions, according to a study by Texas A&M University.

Extreme cold weather can prevent conventional lithium-ion EV batteries from charging or discharging: as the temperature falls, the liquid electrolyte thickens or freezes, blocking the flow of electricity.

Texas A&M University researchers have developed a battery that can maintain functionality in temperatures as low as –40°C. To achieve this, the liquid electrolyte was replaced with a diglyme-based low-temperate electrolyte; diglyme is a liquid organic compound with a very low freezing point, allowing the battery to remain fluid and maintain electrochemical activity even at very low temperatures.

The team also replaced the battery’s hard inorganic electrolyte materials, which are sluggish at low temperatures, with soft polymer materials. During testing, the battery was able to maintain 85% of its capacity at 0°C and 55% at –40°C while sustaining high specific power rates.

Research leader Dr Jodie Lutkenhaus, professor of chemical engineering and associate dean for research at the university, said: “Hard inorganic materials are often slow at low temperatures, but soft polymer materials can move ions more easily. When you use materials that naturally tolerate the cold, the battery doesn’t have to fight its own chemistry.”

The researchers also tackled mechanical durability, another factor that limits battery performance in demanding environments. Instead of using metal current collectors, which can add weight and crack under stress, the team incorporated carbon‑fibre weaves. These reinforced the battery while still conducting charge effectively.

This “structural battery” stores energy and also provides mechanical strength. This dual‑function design could be beneficial in EVs, drones and other systems where both weight and structural integrity are important. 

“Mechanical stress can damage a battery over time,” said Lutkenhaus. “By building batteries that act as part of the structure, we can reduce weight and improve durability at once.”

The research is ongoing, but the team envisions the battery being used for energy storage during episodes of extreme winter weather that could cause electricity grid failure. 

The study, ‘Organic dual-ion batteries with low-temperature operability and structural reinforcement’, has been published in the journal Journal of Materials Chemistry A.