Regulated Ion‐Conductive Electrode–Electrolyte Interface by In Situ Gelation for Stable Zinc Metal Anode

Abstract

Dendritic growth and severe side reactions remain challenging problems for advancing aqueous zinc‐ion batteries. Those critical issues are closely related to the interfacial chemistry, solvation structure, and transportation kinetics of zinc ions. Herein, a regulated ion‐conductive electrode–electrolyte interface (PVA‐Zn(CF3SO3)2‐Si3N4, denoted as PZS) on Zn metal has been in situ constructed, which simultaneously solves the above‐mentioned issues. PZS can effectively accelerate ion transportation and extrude interfacial water, thus endowing dendrite‐free Zn deposition and eliminating side reactions. Benefiting from these features, the PZS‐Zn exhibits stable and reversible Zn stripping/plating with an ultralong cycling life of 3800 h, and an ultrahigh Coulombi efficiency of 99.8%. The full cell paired with the NH4V4O10 cathode runs stably over 1000 cycles at 5 A g−1 with near 100% capacity retention and is demonstrated to cycle up to 200 times along with 71.94% capacity retention in a practical cathode‐anode coupling configuration pouch cell. With this interfacial design, the assembled zinc batteries display excellent cycling stability, paving a practical way for aqueous Zn‐storage systems.

Challenges and Strategies on Interphasial Regulation for Aqueous Rechargeable Batteries

“…Characterization tools especially under operando conditions will benefit the comprehensive understanding of the interphasial chemistry. Typi- The references for the selected materials are: TpPa−SO 3 H, [14] CuHCF, [136] HZC-Ag, [190] COP−CMC/QG, [132] SEI−Zn, [177] ZnS, [48] NEZP, [191] PDA, [192] ZSO, [193] CAZ@Zn, [194] SnS, [195] Zn 2+ −SPEEK, [196] NZSP, [197] CF−Cu, [198] InF 3 , [171] SS@Zn 2+ gel, [199] ZHS, [44] ZSB, [200] PC, [139] PZS, [201] bare-Zn. [202] b) Capacity variation of some electrode materials with artificial coating for aqueous LIBs and SIBs.…”

Constructing Kosmotropic Salt‐Compatible PVA Hydrogels for Stable Zinc Anodes via Strong Hydrogen Bonds Preshielding Effect

“…When the current density was increased to 2 and 4 mA cm −2 , PDHE still showed superior cycling stability and comparable overpotentials to LE (Figure S20, Supporting Information). The designed one-component PVA-based hydrogel electrolyte possesses good low-polarization characteristic at any current density (1, 2, and 4 mA cm −2 ) unrivaled by other PVA-based systems (Figure 4b) and even comparable to that of [31][32][33][34][35][36][37] c) Cycling performance of Zn//Zn symmetric batteries with PDHE and LE at step-up current densities. d) Coulombic efficiency of Zn//Cu batteries cycled at 1 mA cm −2 , 1 mAh cm −2 with different electrolytes.…”

“…[26,28,33,[41][42][43][44] liquid electrolyte (Figure S20, Supporting Information). [31][32][33][34][35][36][37] The low polarization properties of PDHE can be profoundly explained by its microstructure. The presence of a large number of polar functional groups, such as hydroxyl groups, in the molecular structure of PDHE provides abundant sites for zinc ions to be effectively coordinated.…”

“…Figure 4. a) Galvanostatic charge/discharge performance of Zn//Zn symmetric batteries using PDHE, PHHE, and LE at 1 mA cm −2 , 1 mAh cm −2 . b) Comparison of the corresponding voltage hysteresis of PVA-based hydrogels at different current densities in recently reported strategies [31][32][33][34][35][36][37]. c) Cycling performance of Zn//Zn symmetric batteries with PDHE and LE at step-up current densities.…”

Insights Into Electrolyte Strategies for Suppressing Side Reactions Towards Aqueous Zinc‐Ion Batteries

“…In addition, the increase in bound water molecules disrupts the hydrogen bonds between free water molecules, which leads to a reduction of active water molecules, suppressing the H 2 O-induced side reactions. [91,109] Wang et al [93] synthe- [87] sized a ternary cross-linked polymer electrolyte (PCS) comprising PAM, carboxymethyl cellulose, and starch. The presence of starch, which is abundant in hydroxyl groups, contributes to the hydrophilic network structure of PCS.…”