Electrolyte for lithium protection: From liquid to solid

Lithium battery with high energy density and enhanced safety is undoubtedly the ideal choice for consumer electronics and electric vehicles. Metal anode such as lithium has been considered as the most effective way to enhance the energy density as it provides ultra-high theoretical capacity and the lowest redox potential. However, due to the low coulombic efficiency as well as safety concerns originated from dendrite issue of lithium, its further commercial utilization is hindered. Dendrite growth is a common phenomenon in metal electrodeposition while the plating process of Li is more complicated than other metals for its high reactivity nature. As a matter of fact, the Li plating process is accompanied with the generation of solid electrolyte interphase (SEI) in which the electrolyte plays a vital role. In this paper, recent advances of electrolytes for Li protect application are reviewed, from liquid to gel polymer and solid state, on which we find that although tremendous progress has been accomplished, there are still great challenges before Li metal anode could be commercially used. (C) 2019, Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V.