Super-cool battery beats the freeze at -70C

An experimental battery could help improve the performance of devices in the bitter cold of polar winters or even the frigid expanse of space.

Researchers from Fudan University in China created the battery, which reportedly functions at -70^oC – far colder than conventional lithium-ion batteries, which lose 88% of their room temperature capacity at -40^oC. The findings, said authors Yonggang Wang and Yongyao Xia, could help engineers develop technology suitable for extremely cold temperatures.

To tackle the below-zero drop in performance and capacity, the team replaced conventional lithium-ion electrodes with organic polymers that do not rely on intercalation – the process of continuously exchanging molecules between the layered electrodes, which slows down as temperature drops. They combined the electrodes with an ethyl acetate-based electrolyte with a low freezing point.

The result, they said, is a battery capable of conducting charge even at extremely low temperatures. They claimed the technique has several advantages over simply tweaking lithium-ion batteries, which requires additional materials.

“Compared to materials in conventional lithium-ion batteries, organic materials are abundant, inexpensive and environmentally friendly,” said Xia, who estimated that the organic electrodes cost one-third of those in lithium-ion batteries.

However, the researchers said they need to improve the battery’s assembly process and its energy per mass before it is commercialised.

The research was published in Joule.