A computational design method may help engineers design longer-lasting lithium-ion batteries.

The method focuses on selecting optimal materials to use to coat the battery’s cathode, to protect it from degradation and extend battery life.

Christopher Wolverton, Northwestern UniversityLithium-ion batteries use an electrolyte to transport lithium ions as they move between the cathode and the anode, which holds the ions when the battery is charged. When the electrolyte decomposes, it can form hydrofluoric acid, a corrosive chemical that can destroy the cathode over time.

One design strategy is to coat the cathode with a material that resists attack from hydrofluoric acid. However, in the past this process has been slow and clumsy, mostly accomplished through trial and error.

Researchers at Northwestern University addressed this problem using the Open Quantum Materials Database (OQMD) to search for candidate materials. Prof. Christopher Wolverton previously developed the database, which contains information on more than 470,000 compounds.

He and his team developed a method for searching the database for materials that could act as barriers to hydrofluoric acid. Of the 30 candidate materials identified, Dow Chemical Co. tested one and confirmed that it prevented cathode degeneration.

The new design methodology speeds discovery by providing a small, pre-vetted group of candidate materials for testing. The screening process itself is quick, so testing can get underway faster.

The data screening technique applied to the OQMD could also work for the Materials Genome Initiative. This initiative kicked off in 2011 in order to accelerate the discovery, development, and deployment of new materials. The OQMD is open to the public.