From material properties to multiscale modeling to improve lithium-ion energy storage safety

Abstract

Energy storage using lithium-ion cells dominates consumer electronics and is rapidly becoming predominant in electric vehicles and grid-scale energy storage, but the high energy densities attained lead to the potential for release of this stored chemical energy. This article introduces some of the paths by which this energy might be unintentionally released, relating cell material properties to the physical processes associated with this potential release. The selected paths focus on the anode–electrolyte and cathode–electrolyte interactions that are of typical concern for current and near-future systems. Relevant material processes include bulk phase transformations, bulk diffusion, surface reactions, transport limitations across insulating passivation layers, and the potential for more complex material structures to enhance safety. We also discuss the development, parameterization, and application of predictive models for this energy release and give examples of the application of these models to gain further insight into the development of safer energy storage systems.

On the effect of gas generation on heat transfer during thermal runaway of pouch cells

“…The anode main reaction R1 describes the reaction of intercalated lithium with electrolyte solvent, forming lithium carbonate on the anode surface. 22,23 On the anode side, reaction R1 is main contributor to heat release. The main species on the anode surface at elevated temperatures are lithium fluoride and lithium oxide.…”