For instance, in 2017, Nazar’s group reported Li-rich composite alloy films synthesized in situ on lithium by the above two reactions[110]. Due to the lithium alloy and lithium salt composites together form an artificial SEI layer to protect the lithium anode, it can sustain electrodeposition over 700 cycles (1,400 h) of repeated plating/stripping at a practical current density of 2 mA·cm⁻² and a 1,500 cycle-life was realized for a cell paired with a Li₄Ti₅O₁₂positive electrode. Following then, various lithium alloy-lithium salts artificial SEI layers have been proposed, and Table 2 made a conclusion. It can be observed that the metal halides are the most popular candidates to react with lithium and form an inorganic composite artificial SEI layers.

Table 2 Various lithium alloy-lithium salts artificial SEI layers.