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Figure 8. (A) Schematic of interaction relationship in electrolytes. Reprinted with permission from Ref. [152] . Copyright (2020) American
Chemical Society. (B) Schematic illustrations of interfacial stability enabled by the HOMO-LUMO gap of SEI and stable SEI treated
chemically by fluorination. Reprinted with permission from Ref. [156] . Copyright (2019) American Chemical Society. (C) Schematic
illustration of fabrication and working principle of LNO-SRF. Reprinted with permission from Ref. [158] . Copyright (2018) Springer Nature.
(D) Schematic of morphologies of Li deposited on substrate in different electrolytes. Reprinted with permission from Ref. [160] . Copyright
(2015) Springer Nature. (E) Schematic illustrations of passivation films with 1 M and 3 M LiPF in a mixed solvent of EC-EMC-DMC
6
(1:1:1 by vol.). Reprinted with permission from Ref. [163] . Copyright (2020) Springer Nature. (F) Schematic illustrations of effect of NL
cosolvent on solvation structures and thereafter the SEI formation process. Reprinted with permission from Ref. [164] . Copyright (2020)
6-
4-
Wiley-VCH. (G) Optimized geometrical structures of (left) TPFPB-BF and (right) TPFPB-PF complexes. (H) Typical mass spectra via
6-
electrospray ionization and (inset) 3D isosurface rendering of F in PF around DMC and EC molecules. Reprinted with permission from
Ref. [165] . Copyright 2015 American Chemical Society.
regulating the features of the SEI components. In commercial dilute electrolytes, Li ions are generally
+
solvated by the electrolyte solvent molecules with the SSIP structure, leading to a solvent-derived SEI. To
avoid this structure, many anion additives, like LiNO , have been widely developed as effective electrolyte
3
additives to induce CIP structures for fabricating stable anion-derived SEI and realizing uniform Li
deposition [157-159] . Liu et al. found that the previous knowledge regarding the preferential reduction of nitrate
anions during SEI formation in ether-based electrolytes can be extended to carbonate-based systems despite
their extremely limited solubility, which has a positive effect on the ion transport and charge transfer
[158]
kinetics, dramatically altering the nuclei from dendritic to spherical [Figure 8C] . Li et al. introduced both
Li S and LiNO additives to an ether-based electrolyte, which enabled a synergistic effect on the Li surface
3
2 8
that can effectively minimize the electrolyte decomposition and prevent dendrites from propagating
[Figure 8D] .
[160]
More effectively, the concept of high-concentration electrolytes (HCEs) has been widely accepted . With
[161]
increasing salt concentration, the number of free solvent molecules decreases, leading to an increase in the
+
proportion of anions in the solvation shells. The involved coordination of anions transforms the Li
solvation structure from SSIP to CIP and AGGs, which induces an inorganic-rich SEI and stabilizes Li metal
anodes [90,162] . Liu et al. found that both a favorable SEI and cathode electrolyte interphase (CEI) can be