(Invited) Nanostructured Materials for Higher Energy and Higher Power Lithium-Ion Batteries

Abstract

Energy density and cost of Li-ion batteries (LIBs) based on conventional intercalation compounds are closely approaching their limits. The reliance of conventional cathodes on the use of toxic metals additionally endangers health and safety of miners in developing countries. Conversion-type active materials offer an opportunity to double energy stored in LIBs, reduce their cost by the same factor, and improve cell safety. These materials may be produced from safer, cheaper and globally available resources and contribute to accelerated adoption of electric vehicles (EVs). Critically important for the adoption by LIB manufacturing industry, novel materials must serve as drop-in replacements and be fully compatible with existing electrode and cell assembling technologies. Their use should not require additional steps or modified procedures, which often increase production cost and most importantly induce highly-undesired safety or yield risks. As such, all the critical limitations of novel conversion-type materials (large volume changes, undesirable interactions with electrolyte, mechanical instability, slow ion transport, slow electron transport, etc.) should be resolved on the individual particle level via formation of nanocomposites. In order to enable sufficiently low synthesis cost, such nanocomposite particles should be produced using the low-cost bulk reactors and well-established powder production methodologies. Such a strategy enabled success of Sila Nanotechnologies, Inc. to develop and commercialize production of silicon (Si) - based anode materials that experience minimal volume changes and remarkable electrochemical stability during cycling in matched full cells of various sizes.