Forty years after the failed introduction of rechargeable lithium-metal batteries and 30 years after the successful commercialization of the lower capacity, graphite-anode-based lithium-ion battery by Sony, demand for higher energy density batteries is leading to reinvestigation of the problem of dendrite growth that makes the metallic lithium anodes unsafe and prevented commercialization to begin with. One strategy to mitigate dendrite growth is to deposit thin, tailored, corrosion-passivating coatings on the metallic lithium, instead of allowing the metal to spontaneously react with the organic electrolyte solution to form its passivating solid electrolyte interface (SEI). The challenge is to find and to deposit a coating that is electronically insulating yet allows uniform permeation of Li+ at a high cycling rate, such that Li-metal is electrodeposited uniformly on the nanoscale below the tailored coating. Recently, a number of studies have examined multicomponent films, taking advantage of the properties of two different materials, which can be tuned separately or chosen for their complementary properties. Use of these multicomponent coatings will likely enable future researchers to create rationally designed SEIs capable of effectively suppressing the growth of Li dendrites. This review discusses recent developments in micro- and nanoscale tailored coatings to meet that need.

The low cost, abundance, and high capacity of sodium and sulfur make them attractive battery materials. However, formation and migration of polysulfides in sulfur batteries causes rapid capacity fade, limiting battery cycle life. Most strategies to mitigate polysulfide shuttling address migration rather than formation and require complicated or expensive synthetic steps. Here, we introduce an amorphous, sulfur-rich molybdenum sulfide as a sulfur equivalent cathode that is simple and easy to make and shows excellent cycling performance with a specific capacity of 537 mAh g–1 at 50 mA g–1, retaining over 200 mAh g–1 at a rate of 1 A g–1.