Electric vehicles and related battery technologies are all the rage right now. But some University of Michigan engineers recommend pumping the brakes to answer some important questions about next-gen EV batteries before pushing the devices from the lab to manufacturing facilities. 

Lithium-ion batteries have kept their stronghold as the most common EV power source. But researchers have shown potential for doubling EV range while reducing the risk of fires by using lithium metal solid-state batteries. The solid-state battery’s anode is lithium and a ceramic is used for the electrolyte.

Although “tremendous progress” has been made over the last decade to advance both lithium-ion and solid-state batteries, several challenges remain, especially when using the batteries in EVs, Jeff Sakamoto, UM associate professor of mechanical engineering, said in a news release.

Sakamoto says enthusiasm for these technologies should not overshadow solid research and cause the industry to get ahead of itself in battery commercialization. His research team put forth five questions to answer to capitalize on lithium metal solid-state batteries’ potential:

• Ceramics are brittle. How can they be produced in the massive, paper-thin sheets needed for lithium batteries?
• Manufacturing ceramics requires a lot of energy to heat them — to more than 2,000 degrees Fahrenheit. Does using the energy-intensive ceramics in lithium batteries offset the environmental benefits of EVs?
• Can the ceramics and their manufacturing process be adapted to account for defects, like cracking, without forcing battery and automakers to drastically revamp their operations?
• Lithium metal solid-state batteries would not need the heavy, bulky battery management system that lithium-ion batteries need to maintain durability and reduce fire risk. How will the reduction or removal of a battery management system affect a solid-state battery’s performance and durability?
• Additional hardware is necessary to apply pressure in lithium solid-state batteries because the lithium metal must remain in constant contact with the ceramic electrolyte. What will the extra hardware mean for battery performance?

The team says these questions need to be answered quickly to advance a promising power supply — lithium metal solid-state batteries — as efforts are underway to significantly increase electric vehicle adoption. The UM team recommends further rigorous testing and data analysis on the advanced batteries in addition to transparency in research.