Interfacial Chemistry Modulation via Amphoteric Glycine for a Highly Reversible Zinc Anode

Abstract

Zn metal is thermodynamically unstable in aqueous electrolytes, which induces dendrite growth and ongoing parasitic reactions at the interface during the plating process and even during shelf time, resulting in rapid battery failure and hindering the practical application of aqueous Zn ion batteries. In this work, glycine, a common multifunctional additive, is utilized to modulate the solvation shell structure and enhance the interfacial stability to guard the reversibility and stability of the Zn anode. Apart from partially replacing the original SO4 2– in the contact ion pair of Zn2+[H2O]5·OSO3 2– complexes to suppress the formation of Zn4(OH)6SO4·xH2O byproducts at the interface, glycine molecules can also form a water-poor electrical double layer on the zinc metal surface during resting and be further reduced to build in situ a ZnS-rich solid electrolyte interphase (SEI) layer during cycling, which further suppresses side reactions and the random growth of Zn dendrites in the whole process. As expected, the cycle life of the symmetrical cells reaches over 3200 h in glycine-containing electrolytes. In addition, the Zn//NVO full cell shows exceptional cycling stability for 3000 cycles at 5 A g–1. Given the low-cost superiority of glycine, the proposed strategy for interfacial chemistry modulation shows considerable potential in promoting the commercialization progress of aqueous batteries.

Selection criteria for electrical double layer structure regulators enabling stable Zn metal anodes

“…4h). A similar mechanism that turns the disadvantage of consuming H + into the advantage of forming a stable SEI layer was also reported in previous work, 53,58–62 which further confirms the credibility of our explanation. To experimentally confirm the critical effect of this unique SEI layer, we calculated the activation energy for the de-solvation process of Zn(H 2 O) 6 2+ through the law of Arrhenius equation (Fig.…”

All-round supramolecular zwitterionic hydrogel electrolytes enabling environmentally adaptive dendrite-free aqueous zinc ion capacitors

“…7b). 22,24,28,32,40,[43][44][45] Specifically (Fig. 7c), the zwitterionic molecules can be directionally adsorbed on the Zn anode surface under an applied electric field, further forming chainlike aggregation due to the electrostatic interactions between the negatively charged carboxylate/oxygen and positively charged nitrogen, which thereby construct a waterproof layer that successfully expels water from the Zn anode surface.…”

“…This strong chemical adsorption introduces a water-poor electrical double layer (EDL), which can effectively inhibit the competitive adsorption of H 2 O and its subsequent induced side reactions. 40 After introducing the zwitterionic betaine additive, free H 2 O molecules are trapped by the supramolecular betaine chains, binding EG via H-bonds, which affords low accessibility for its involvement in the interfacial reactions and lowers the proton activities (Fig. S40, ESI †).…”

“…16,20,[27][28][29][30][31][32][33][34][35][36][37] Thus, to overcome this bottleneck, a promising strategy is the incorporation of organic additives (e.g., glycerol (GL) and ethylene glycol (EG)) to not only achieve an ultra-low freezing point by forming strong H-bonds with H 2 O but also regulate the Zn 2+ -solvation structure by coordinating with Zn 2+ for the suppression of dendrite growth and side reaction. [36][37][38][39][40] However, the radius of the Zn 2+ -solvation structure is enlarged during coordination, which dramatically jeopardizes the ionic conductivity of HEs especially at subzero temperatures. 41 Thus, the goal is to find an HE material with integrated characteristics of excellent mechanical performance, high ionic conductivity, exceptional interfacial adhesion, desired self-healability, and superior environmental adaptability.…”

Flexible Electronic Systems via Electrohydrodynamic Jet Printing: A MnSe@rGO Cathode for Aqueous Zinc-Ion Batteries

“…11 Among the emerging aqueous metal-ion batteries, zinc-ion batteries (ZIBs) are particularly interesting because of the abundant crystal reserves of Zn (70 ppm), the relatively small ionic radius of Zn 2+ (0.74 Å), and weak reactivity of Zn toward air and water. 12 Flexible ZIBs can be fabricated in an atmospheric environment because of the air stability of the aqueous ZIB system, thereby considerably simplifying the fabrication process. 13 Flexible ZIBs have been produced using various fabrication technologies, including vacuum filtration, photolithography, electrodeposition, and laser scribing and printing.…”