Following months of promising test results, battery researchers at the Department of Energy’s Oak Ridge National Laboratory are recommending that the solid-state battery industry focus on a technique known as isostatic pressing as it looks to commercialize next-generation batteries.

Commercial-scale production of solid-state batteries is a goal for electric vehicle manufacturers because these batteries have the potential to charge faster, last longer and operate more safely than the lithium-ion batteries currently on the market.

In a focus review paper for ACS Energy Letters, ORNL researchers recommend attention be given to the little-studied isostatic pressing approach. This process uses fluids and gases like water, oil or argon inside a machine to apply consistent pressure across a battery component, creating a highly uniform material. With the help of an industry partner that produces this pressing equipment, ORNL researchers found that isostatic pressing could make battery production easier and faster while creating better conditions for energy flow.

When a battery charges or discharges, ions move through an electrolyte between its positive and negative poles, which are made of thin layers of metal. In the lithium-ion batteries that power everything from cell phones to electric vehicles, the electrolyte is a liquid through which ions travel easily. Unfortunately, this liquid can also spill or ignite if the separation between battery layers is compromised.   

ORNL’s Marm Dixit and colleagues found that isostatic pressing can create thin layers of solid, uniform electrolyte, maintaining a high level of contact between the layers for smooth ion movement. The method works with a variety of battery compositions at different temperatures and pressures.