A research team at the US Department of Energy Oak Ridge National Laboratory (ORNL) has developed a new material that it claims prevents lithium-ion batteries from bursting into flames.
Lithium-ion batteries can be prone to fires when the thin piece of plastic that separates the electrodes fails due to damage. The electrodes come into contact and cause the liquid electrolyte to set fire.
Researcher Gabriel Veith and his team developed a form of shear thickening for electrolytes. Shear thickening is a reversible behaviour that involves liquid substances becoming solid under pressure. Veith said he was inspired when playing with his children. They were playing with a mix of cornstarch and water known as oobleck that would flow like a liquid until it was poked. The researchers at ORNL set out to mix an oobleck-like additive into a conventional electrolyte for an impact resistant material, and used a silica suspended in common liquid electrolytes for lithium-ion batteries.
It solidifies when hit and prevents the electrodes of the battery from touching if there is damage from a fall or crash. This characteristic depends on a colloid, which is a suspension of tiny, solid particles in a liquid. The research team used neutron scattering at ORNL’s Spallation Neutron Source, a DOE science facility, to understand the fundamental interactions during impact.
In 2022, ORNL licensed the collection of five patented technologies, called Safe Impact Resistant Electrolytes, or SAFIRE, to battery startup Safire Technology Group. The firm opened its R&D operations in Tennessee as part of its plan to commercialize the technology with an emphasis on applications in EV, defence, and electric vertical take-off and landing (eVTOL) aircraft.
“The best part of working at ORNL is the team environment. This team has a rheologist, a ceramicist, an electrochemist, mechanics experts, materials testers — all those together make this technology work,” Gabriel Veith said. “This is not the work of a single person — teamwork allowed us this really unique opportunity. Having a diversity of people, experiences and backgrounds really helps to develop ideas.”
“Improving battery technology is critical to building a clean energy future for our country,” said Susan Hubbard, ORNL deputy for science and technology. “This technology has implications for several industries, ultimately making battery systems safer, more efficient, and more stable.”
Image: Researcher Gabriel Veith, who is part of the team researching electrode additives to prevent lithium-ion battery fires. Credit: Carlos Jones/ORNL.
