Modulation of Li+ microenvironment in liquid electrolyte for interface design of Li-metal anodes

While lithium metal anodes (LMAs) offer the highest energy density, positioning them as a promising material for graphite, they suffer from uneven electroplating morphology and the formation of Li dendrites. Given the pivotal role of the solid-electrolyte interphase (SEI), which is formed by electrolyte decomposition, in mitigating dendritic growth, extensive research has been conducted on liquid electrolytes in Li metal batteries (LMBs). This mini-review presents the historical advancements in LMB electrolytes, focusing on modulating the Li⁺ microenvironment and LMA interface chemistry to inhibit Li dendrite formation. We traced the evolution of LMB electrolytes from traditional formulations to advanced designs. In particular, the reinforcement of the SEI and the compact morphology of the deposited Li are deeply discussed at each advancement in liquid electrolytes. We subsequently identify common characteristics among these advanced electrolytes and conclude by discussing future directions and strategies for rational design.