Electric vehicle battery safety takes the front seat

A Sandia-led team is working to test and predict the safety of advanced batteries, including solid-state and lithium-metal, while they are still under development. The goal is to create more affordable, convenient, efficient, and resilient electric vehicle batteries.

The team, which includes UL Research Institutes, the University of Maryland and Purdue University, received $3.7 million from DOE’s Advanced Research Projects Agency-Energy’s Electric Vehicles for American Low-carbon Living program. Their aim is to develop a combined experimental methodology and modeling framework approach to improve safety in battery development. The project will result in a publicly available, multiscale testing manual and modeling tool to predict a battery’s safety profile.

“We want to understand how batteries fail and why they fail,” said Loraine Torres-Castro, chemical engineer and project co-lead. “It’s critical to characterize battery safety hazards early in the design process. This is the first time a funding opportunity has safety taking the front seat for battery research.”

Most battery safety research happens after the battery has been developed and is close to commercialization, Torres-Castro said. However, that approach takes a lot of research and development, funding and manufacturing time.

“You don’t typically see thermal runaway at small scales,” said Alex Bates, chemical engineer and project co-lead. “That’s a big issue with the traditional way of studying battery safety. The safety profile can significantly change as the cell size is scaled up to a commercial size, and that takes a lot of time and investment.”

Instead, the team will work to link the small-scale characteristics from calorimetry and materials-level analysis of various battery materials to a large-scale response through predictive modeling.

To do this, the team will assemble microcells of battery materials, which are tiny stacks of the components that go inside the larger battery cell, heat them up and study how heat releases from the material. Data from these experiments, combined with materials characterization, will be used in a modeling framework to predict the safety of larger cells.

“If the materials are reactive, you’ll see an exothermic event, with more heat releasing than what was put in, even at the materials level,” Bates said. “That kind of reaction, when scaled up to a full-size battery, could potentially cause a fire.”

Kyle Fenton, the power sources manager, said the Battery Abuse Testing Lab has focused on understanding battery mechanisms, safety and fundamentals for the last 20 years.

“We have lots of expertise in this area of research, but EVs4ALL is one of the biggest opportunities we’ve had to focus on the fundamentals and safety of emerging energy storage technologies.”