Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have patented a new molecule that provides overcharge protection for lithium-iron-phosphate batteries.”The new redox shuttle, known as 2,5-di-tert-butyl-1,4-bis(2-methoxyethoxy)benzene or DBBB, works by halting the charging process of individual cells as they come to a full state of charge,” Argonne materials scientist Khalil Amine said. “Being able to discontinue the charging process on a cell-by-cell basis protects the entire battery pack by preventing individual cells from overcharging.” Currently overcharge is being addressed by expensive and complicated battery management system that use external cell monitoring and control devices. Overcharge can cause damage to the battery, reduce cell life and in extreme case result in thermal runaway. Thermal runaway is a safety concern for large batteries used in electric vehicles or storage application since they contain a large amount of active material. This new material offers a tool for addressing some of the concerns associated with overcharge using an approach that functions inside each cell.
The shuttle is currently undergoing validation test by industry, and the results to date are very encouraging, Amine informed. Researchers in Argonne’s Advanced Battery Materials Synthesis and Manufacturing Research & Development Program have already scaled up production of DBBB as a step towards commercial production. The stability and repeated long-term overcharge cycling capability of this new shuttle molecule was demonstrated by Amine and his Argonne colleagues Zhengcheng Zhang, Lu Zhang and Wei Weng. The research was funded by the DOE Office of Energy Efficiency and Renewable Energy.
