New battery technology could lead to safer electric vehicles

The new technology, first presented in Nature on October 25, 2023, suppresses the growth of lithium dendrites in lithium-ion batteries, which are branch-like structures that can cause short circuits and lead to failures in the long term.

This new design for a battery ‘interlayer’ is said to stop dendrite formation and could lead to the production of safer all-solid-state batteries for EVs, according to the researchers.

Lithium-ion batteries are popular for EVs due to their high energy storage, but they contain a flammable liquid electrolyte component that burns when overheated. The US National Transportation Safety Board reports that first responders are vulnerable to safety risks, including electric shock and the exposure to toxic gasses emanating from damaged or burning batteries.

The researchers aimed to offer a solution to this risk by stabilising the battery’s interfaces between the solid electrolyte and the anode and the electrolyte and the cathode.

The new battery structure adds a fluorine-rich interlayer that stabilises the cathode side, as well as a modification of the anode’s interlayer with magnesium and bismuth—suppressing the lithium dendrite, according to research test results.

Professor Chunsheng Wang, department of chemical and biomolecular engineering, and postdoctoral associate Hongli Wan, first developed a theory for the formation of lithium dendrite growth in 2021, which remains a matter of scientific debate, the researchers said, but provided the foundation for their new battery design.

In a statement, professor Wang, said: “All-solid-state batteries could lead to cars that are safer than current electric or internal combustion models, but creating a strategy to bypass the drawbacks was laborious.

“Solid-state batteries are next-generation because they can achieve high energy and safety. In current batteries, if you achieve high energy, you’ll sacrifice safety.”

To commercialise all-solid-state batteries, experts will have to scale down the solid electrolyte layer to achieve a similar thickness to the lithium-ion batteries’ electrolyte, which will improve energy density and battery storage. High costs of basic materials are another challenge, the team said.

Battery manufacturer Solid Power plans to begin trials of the new technology to assess its potential for commercialisation, with the aim to release the new batteries to market by 2026 if the trials are successful.