Dynamic Biomolecular “Mask” Stabilizes Zn Anode

Abstract

Zn anode is confronted with serious Zn dendrite growth and water‐induced parasitic reactions, which severely hinders the rapid development and practical application of aqueous zinc metal batteries (AZMBs). Herein, inspired by sodium hyaluronate (SH) biomolecules in living organisms featured with the functions of water retention, ion‐transport regulation, and film‐formation, the SH working as a dynamic and self‐adaptive “mask” is proposed to stabilize Zn anode. Benefiting from the abundant functional groups with high hydrophilicity and zincophilicity, SH molecule can constrain active water molecules on the Zn‐electrolyte interface and participate in Zn2+ solvation structure to suppress parasitic reactions. Furthermore, the dynamical adsorption of SH with high‐density negative charge on the Zn surface could serve as Zn2+ reservoirs to guide uniform Zn deposition. Consequently, stable Zn plating and an ultrahigh cumulative plating capacity (CPC) of 4.8 Ah cm‐2 are achieved even at 20 mA cm‐2 (20 mAh cm‐2) in a Zn||Zn symmetric battery, reaching a record level in AZMBs. In addition, the Zn||β‐MnO2 full battery exhibits a substantially improved cycle stability. This work presents a route to realize a highly reversible and stable Zn metal anode by learning from nature.

Electrolyte Regulation of Bio‐Inspired Zincophilic Additive toward High‐Performance Dendrite‐Free Aqueous Zinc‐Ion Batteries

“…A blue shift of OH stretching mode (3200–3400 cm −2 ) with an increasement of Gly concentration implies that the strength of OH covalent bonds from H 2 O molecule is significantly increased (Figure S5, Supporting Information). [ 35,36 ] These experimental results lead to the conclusion that incorporation of Gly additive enables a reconstruction of the solvation sheath of hydrated Zn 2+ and modulate the local chemistry environment of the aqueous electrolyte.…”

“…As presented in Figure 2e, a sharp peak of the ZnO pair at 2 Å is detected which indicates the presence of H 2 O molecules in the solvation structure. [34,36] After statistical analysis, the ACN of ZnH 2 O is calculated to be around 5.4 in the pure ZnSO 4 electrolyte, whereas the ACN of ZnH 2 O in the Gly-containing electrolyte system is reduced to 5.1. This result reveals that the Gly additive can alter the solvation sheath of hydrated Zn 2+ ions by partially replacing the coordinated water molecules.…”

Fast and Regulated Zinc Deposition in a Semiconductor Substrate toward High‐Performance Aqueous Rechargeable Batteries

“…[1][2][3] Among these aqueous batteries, aqueous rechargeable Zn-ion batteries (AZIBs) have been believed to be one of the promising candidates for large-scale energy storage due to their natural characteristics, including low cost, low redox potential (−0.76 V vs. standard hydrogen electrode), natural abundance, and high theoretical capacity (820 mAh g −1 and 5855 mAh cm −3 ). [4][5][6] However, the Zn metal is thermodynamically unstable even in mild electrolytes, where the Zn anode continuously suffers from severe side reactions during cycling. [7][8][9] In detail, the parasitic reactions, i.e., hydrogen evolution reaction (HER), increase the local pH environment and induce the formation of surface passivation and dendrites, leading to low Coulombic efficiency (CE), which significantly restricts the practical applications of AZIBs.…”

Advances and strategies of electrolyte regulation in Zn-ion batteries

“…78 Some other electrolyte additives containing polar functional groups are also used to suppress Zn dendrite growth and H 2 evolution, such as, sericin molecules, cysteine, sodium hyaluronate, threonine, etc. 58,[79][80][81][82][83] Many of them are more likely to adsorb on the Zn anode to create a solid SEI, which can efficiently stop the decomposition of H 2 O and direct uniform Zn deposition.…”