Fig. 1

Issues of zinc anode/electrolyte interface"

Fig. 2

Regulation mechanisms of electrolyte additives"

Fig. 3

(a) Schematic diagram of Na+ inhibiting the dissolution of NaV3O8·1.5H2O and zinc dendrite formation[46]; (b) The cycling performance of Zn-Zn symmetrical cells with or without TEAB[67]; (c) Coulomb efficiency performances of Zn-Ti cells in different concentrations of electrolyte additives[75]; (d) Schematic diagram of coherent deposition of zinc particles induced by a compressed double electric layer[77]"

Fig. 4

(a) The adsorption energy of H2O, Sac, and Sac anions on Zn (0001) surface[69]; (b) The schematic descriptions of EDL structure before and after introducing Sac[69]; (c) The CE of Zn-Cu cells using Sac/ZnSO4 and ZnSO4 electrolyte[69]; (d) Schematic of Zn/electrolyte interface behaviors during Zn deposition in ZnSO4 and ZnSO4 electrolyte with MSG[78]; (e) XRD patterns of Zn electrode before and after 20 cycles in the designed electrolyte[71]; (f) Plot of long cycle performance and efficiency of Zn-V2O5 cells at 0.8 A/g current density[71]; (g) Schematic illustration of the pH evolution of different electrolytes and the interfacial pH buffer mechanism enabled by the OAc-anion[79]"

Fig. 5

(a) Schematics of morphology evolution for Zn anodes in mild aqueous electrolyte with and without Et2O additive during Zn deposition/dissolution cycling[68]; (b) 3D snapshot of ZnSO4-SBT system and partial enlarged image representing Zn2+ solvation shell structure[81]; (c) Schematic diagram of Zn2+ deposition process in electrolyte system without SBT and with SBT[81]; (d) Long cycle performance of Zn-Zn symmetrical cells in ZnSO4 and ZnSO4-SBT[81]; (e) Schematics of deposition for Zn anodes in ZnSO4 and ZnSO4 with Gly additive systems[50]; (f) Schematic diagram of zinc deposition in AM additive[83]"

Fig. 6

(a) Schematic diagrams of the bonding networks in different aqueous electrolytes with and without polymer additives[87]; (b) Coulombic efficiency and cycling performance of Zn anodes in 1 mol/L ZnSO4 aqueous electrolytes with different polymer additives using the Zn-Cu cells under 1 mA/cm2, 1 mAh/cm2[87]; (c) Schematic illustration of the relationship among silk sericin, fibroin, and peptide molecules with diverse conformations and polar groups, and their applications as electrolyte additives in AZMBs[89]; (d) In situ optical observations of Zn deposition morphologies in the ZnSO4 electrolytes with/without silk peptide at a current density of 10 mA/cm2[89]; (e) Coulomb efficiency of Zn-Cu cells in ZnSO4 electrolyte containing different concentrations of silk peptide additive[89]; (f) Cycling performance of Zn-Zn symmetric cells in the ZnSO4 aqueous electrolytes with/without silk peptide[89]"

Fig. 7

(a) The electric field distribution on the surface of zinc anode with and without GO electrolyte additive. The vectorial field describes the direction of the electric field[91]; (b)—(c) TEM and HRTEM (insert in c) images of as-prepared GQDs[92]; (d) AFM image of the GQDs on the mica substrate and corresponding height profile of the origin line A-B[92]; (e) Long-term cycling profiles of the Zn||Zn symmetric cells with and without GQDs additive at 2 mA/cm2 and the corresponding voltage profiles[92]; (f) Pristine C3N4QDs on mica (left) and the C3N4QDs in ZnSO4 aqueous electrolyte on HOPG (right), the inset is the height profiles of the corresponding lines[93]; (g)—(o) In situ AFM images of Zn electrodeposits on HOPG with a current density of 100 μA/cm2 in electrolyte with C3N4QDs (g)—(j) and without C3N4QDs (k)—(o)[93]; (p) Schematic illustration of using [BMIM]OTF additive to stabilize the Zn deposition process[95]; (q) Cycling performances at 5 mA/cm2 and 25 mAh/cm2[95]"