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 transportation. Formation of effective nanocomposites is likely a necessity for the successful commercialization of conversion-type electrodes. I will discuss approaches taken by our laboratory to address current challenges of such materials. Conventional polymer separators for LIBs suffer from limited mechanical strength and low thermal stability, which may lead to thermal runaway and cell explosion. I will discuss our studies on the low-cost formation of flexible, binder-free, nonwoven separators composed of alumina nanowires that overcome the known limitations.