Lithium metal batteries are capable of attaining a remarkable energy density surpassing 500 Wh kg−1, which is pivotal in mitigating range-related apprehension associated with electric vehicles and promoting the evolution of consumer electronic devices. Unfortunately, commercial carbonate electrolytes are unsuitable for lithium metal anodes due to the uncontrollable growth of dendrites and the degradation of the electrode-electrolyte interface. Localized high-concentration electrolytes (LHCE) is produced through the augmentation of salt concentration and the inclusion of an uncoordinated counter-solvent, which can facilitate the formation of an inorganic-rich solid electrolyte interphase (SEI) and benefit for the reversible cycling of the lithium anode. However, the mechanisms of Li+ transport, de-solvation, and the roles of counter-solvents for anode protection are not yet fully elucidated. This review provides an analysis of the solvation structure of LHCE and the fundamental principles governing the Li⁺ de-solvation process, with particular emphasis on the counter-solvent's role as a solvation structure and interfacial chemistry modulator. Furthermore, this review delivers a comprehensive survey of the current landscape of LHCE formulations based on different kinds of counter-solvents, aiming to contribute meaningful insights to the progress and commercialization of lithium metal battery technology.