Single-Ion Conducting Double-Network Hydrogel Electrolytes for Long Cycling Zinc-Ion Batteries

Abstract

As one of the promising alternatives of lithium-ion batteries, zinc-ion batteries (ZIBs) have received growing interest from researchers due to their good safety, eco-friendliness, and low cost. Nevertheless, aqueous ZIBs are still a step away from practical applications due to the nonuniform deposition of Zn and parasitic side reactions, which cause capacity fading and even short circuit. To tackle these problems, here we introduce a single-Zn-ion conducting hydrogel electrolyte (SIHE), P­(ICZn-AAm), synthesized with iota carrageenan (IC) and acrylamide (AAm). The SIHE manifests single Zn2+ conductivity via the abundant sulfates fixed on the IC polymer backbone, delivering a high Zn2+ transference number of 0.93. It also exhibits outstanding ionic conductivity of 2.15 × 10–3 S cm–1 at room temperature. The enhanced compatibility at the electrode–electrolyte interface was verified by the stable Zn striping/plating performance along with a homogenous and smooth Zn deposition layer. It is also found that the passivation of the Zn anode can be effectively prohibited due to the lack of free anions in the electrolyte. The practical performance of the SIHE is further investigated with Zn–V2O5 batteries, which showed a stable capacity of 271.6 mA h g–1 over 150 cycles at 2 C and 127.5 mA h g–1 over 500 cycles at 5 C.

Hydrogen Bond‐Functionalized Massive Solvation Modules Stabilizing Bilateral Interfaces

“…Considering the contradictory from their ion migration numbers, this is contrary to the view that cycling stability often depends on the ionic conductivity of electrolyte. [25,32] Therefore, understanding the microscopic characteristics of electrolyte is of great significance to analyze the performance differences of the batteries such as stability. Furthermore, a wide temperature range of the electrolyte provides the host batteries opportunity to operate at extreme situations (Figure S7a,b, Supporting Information).…”

Dual Porous 3D Zinc Anodes toward Dendrite-Free and Long Cycle Life Zinc-Ion Batteries

“…To build dendrite-free Zn anodes, some effective methods have been proposed to uniformize the surface electric field and inhibit Zn dendrite growth, including electrolyte additives, artificial SEIs, and structured anodes. − Recently, a facile layered rGO coating is reported as a Zn anode protection layer to suppress dendrite growth. Compared with bare Zn, the Zn/rGO anode shows lower overpotential and excellent long-life cycling stability credited to the good electrical conductivity and large surface area of graphene .…”

A flexible and highly ion conductive polyzwitterionic eutectogel for quasi-solid state zinc ion batteries with efficient suppression of dendrite growth

“…6 shows the current densities of various hydrogels used for Zn ion batteries at various working times, and clearly, the PSPE eutectogel showed much higher performance than the other reported systems. 10,15,24,29,35,43,44 In addition, the zinc ion battery with the PSPE eutectogel electrolyte has an energy density of 165 W h kg À1 , and exhibits high performance compared to the currently reported zinc ion batteries (Fig. S17, ESI †).…”