Production of lithium metal with ion-selective solid electrolytes

The alkali metal lithium(Li)has the smallest density and the most negative Redox potential[1].It is considered as one of the critical elements by many countries[2].The reasons are several-fold:1)Many important applications need huge amounts of Li[3],such as lithium ion batteries(LIBs)as the most famous example,which was honored with the Nobel Prize of Chemistry in 2019[4];2)The abundance of Li in the earth's crust is limited,400 times lower than that of sodium[3];3)The geographical distribution of Li resources is uneven and dilute with 90%in brines[5];4)The mining process is tedious and complicated[3];5)The production of highly-pure Li metal is energy-extensive and cost-inefficient[6];6)It is difficult to recycle many end products of Li,for instance,those Li-containing compounds in LIBs[3].Thus,Li needs to be used wisely,produced economically,and recycled efficiently.