In Pursuit of a Dendrite-Free Electrolyte/Electrode Interface on Lithium Metal Anodes: A Minireview

As one of the most promising electrode materials, lithium metal has excellent performance with its ultrahigh theoretic specific capacity (3860 mAh/g) and the lowest potential (-3.04 V versus standard hydrogen electrode). Nevertheless, the practical application of lithium metal batteries is hindered by the low coulombic efficiency and safety issues, which originate from the uneven Li deposition/dissolution process and the continuous growth of lithium dendrites. The composition, structure, and morphology of the solid-electrolyte interface (SEI) are key factors in regulating the lithium deposition behavior and suppressing dendrite growth. In this review, the failure mechanism of the lithium metal anode and structural and compositional properties of ideal and practical SEIs are briefly summarized, including models describing the ion transfer process and the evolution of uneven lithium deposition at the interface. There are three main strategies to obtain a high-performance lithium metal anode from the perspective of regulating the electrolyte/electrode interface. They are (i) liquid electrolyte regulation, (ii) solid electrolyte application and separator modification, and (iii) electrode interface coating and composite anode. Lastly, the remaining challenges to be further solved and possible directions for future development are discussed.