The NO-CNS with abundant surface negative charges not only creates an interfacial high-concentration of lithium ions near the electrode surface to promote chargetransfer kinetics but also enables a high ionic conductivity in the bulk electrolyte to improve ionic mass-transfer., This work proposes a quasi-localized high-concentration electrolyte (q- LHCE) by partially replacing solvents in conventional LiPF 6 based carbonated electrolyte with fluorinated analogs (fluoroethylene carbonate (FEC), 2,2,2-trifluoroethyl methyl carbonate (FEMC)) with weakly-solvating ability., The lithium metal batteries coupled with nickel-rich LiNixCoyMn1–x–yO2 (x > 0.7) cathodes hold promise for surpassing the current energy density limit of lithium-ion batteries., Compared with traditional electrolytes, high-concentration electrolytes (HCEs) have a higher ion transfer number, wider electrochemical window, higher thermal stability, low volatility, good flame resistance, and passivation of Al current collector at high potential., Recently, novel localized high-concentration electrolytes (LHCEs) were introduced as a potential solution to enable dendrite-free cycling of LMAs, by using an inert solvent to “dilute” the high concentration electrolytes., Herein, we systemically review the latest progress in high-concentration and localized-high-concentration electrolytes for use in Li metal batteries. The solvation chemistry structure,.