The U.S. Department of Energy's (DOE) Argonne National Laboratory on Tuesday announced that scientists have developed a new cathode coating using an oxidative chemical vapor deposition technique that can help solve several potential issues with lithium-ion batteries.
Compared to conventional coatings, which only protect the exterior surface of the cathode particles, the new so-called PEDOT coating has the ability to penetrate to the cathode particle's interior, adding an additional layer of shielding.
"The new coating is expected to be commercially available in the next few years," Khalil Amine, a distinguished fellow and battery scientist at Argonne, told Utility Dive.
The growing global energy storage market — which is expected to see 4.3 GW of grid-connected storage deployed this year, according to IHS Markit — received another boost this week as scientists discovered a new coating that solves some of the industry's biggest concerns: density and safety.
An explosion last month at an Arizona Public Service battery facility that sent four fire fighters to the hospital highlighted those concerns.
Two years of research and optimization resulted in a coating that prevents the chemical interaction between the battery and electrolyte, while at the same time allowing all other battery processes to function without interference, Argonne said in a press release.
"This coating is essentially friendly to all of the processes and chemistry that makes the battery work and unfriendly to all of the potential reactions that would cause the battery to degrade or malfunction," Argonne chemist Guiliang Xu said.
Amine, who was the primary researcher, told Utility Dive he expects the coating to be commercially available within the next few years.
"The coating we've discovered really hits five or six birds with one stone," he said.
By increasing energy density of lithium-ion batteries, the new cathode coating, called PEDOT, is expected to reduce overall battery costs, which in turn will enable mass electrification, Amine said in an email.
The national laboratory also indicated that battery scientists could likely scale up the coating for use in nickel-rich nickel-manganese-cobalt (NMC) containing batteries.
"This PEDOT coating was also found to be able to suppress oxygen release during charging, which leads to better structural stability and also improves safety," Amine said in a statement.
Last week, Argonne tackled another important issue related to lithium-ion batteries: performance comparison.
The laboratory said that assessing whether an innovation in electrode or electrolyte material is actually an improvement means comparing test results. But there is no standardized testing method for lithium-ion batteries, they added.
"Industrial engineers and researchers from governmental and academic labs often devise their own procedures for characterizing lithium-ion batteries based on the battery technology's intended application. This makes the comparison of any technological innovations extremely complicated," Argonne battery researcher Ira Bloom said in a statement.
To solve this problem, Argonne teamed up with the University of Warwick, OVO Energy, Hawaii National Energy Institute and Jaguar Land Rover to review the literature on the various testing methods used around the world to characterize the performance of lithium-ion batteries in order to provide insight on best practices.
The hope "is that our results may one day lead to more reliably comparable methods for testing lithium-ion batteries tailored to different applications," Bloom said.