Flame retardant incorporation into Lithium-ion batteries

The use of Lithium-ion batteries (LIB’s) in commercial electronics such as computers and cell phones has expanded in recent years. LIB technology offers higher energy density, lower self-discharge as well as higher operating voltage vs. other rechargeable battery technologies. However, the natural flammability of standard LIB carbonate based electrolyte along with risk of thermal runaway poses safety concerns. Thus, the research and development of nonflammable alternative electrolyte mixtures for standard LIB’s is of high interest to researchers. To that end, Organophosphate containing Flame retardant (FR) compounds are being investigated as they possess natural fire suppressing qualities. LIB utilization in large platform applications, such as electric vehicles (EV’s) and aerospace designs has stimulated interest in higher energy density electrode materials such as Si. However, the practical use of Si does bring with it challenges related to the enormous volume changes which take place during cycling. The use of LIB’s for large high energy applications raises elevated safety concerns relating to thermal runaway. Detailed investigations relating to the benefit, cycling performance, and effect on the solid electrolyte interphase (SEI) upon FR incorporation into LIB’s with various anodes with/without SEI film stabilizing agents will be presented. SEI composition and structural changes upon FR incorporation are analyzed via surface analysis techniques including SEM and XPS.