Quasi-Solid-State “Water-in-Swelling-Clay” Electrolytes Enabling Ultrastable Aqueous Zinc-Ion Batteries

14 March 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


The poor reversibility of Zn metal anodes arising from water-induced parasitic reactions poses a significant challenge to the practical applications of aqueous zinc-ion batteries (AZIBs). Herein, a novel quasi-solid-state water-in-swelling-clay electrolyte (WiSCE) containing zinc sulfate and swelling clay bentonite (BT) is designed to enable highly reversible Zn metal anodes. AZIB full 2 cells based on the WiSCE exhibit excellent cyclic stability at various current densities, long shelf life, low self-discharge rate, and outstanding high-temperature adaptability. Particularly, the capacity of WiSCE-based AZIB full cells retains 90.47% after 200 cycles at 0.1 A/g, 96.64% after 2000 cycles at 1 A/g, and 88.29% after 5000 cycles at 3 A/g. Detailed density functional theory calculations show that strong hydrogen-bonds are formed between BT and water molecules in the WiSCE. Thus, water molecules are strongly confined by BT particularly within the interlayers, which significantly inhibits water-induced side reactions and thus greatly improves cyclic stability. Compared to the state-of-the-art water-in-salt electrolyte, the WiSCE can provide a significantly higher capacity at the full-cell level with a substantially reduced cost, which is promising for the design of next-generation high-performance AZIBs. This work provides a new direction for developing cost-competitive AZIBs as alternatives in grid-scale energy storage.


Bentonite clay
Electrolyte additives
Zn metal anodes
Aqueous zinc-ion batteries

Supplementary materials

A Low-Cost Quasi-Solid-State “Water-in-Swelling-Clay” Electrolyte Enabling Ultrastable Aqueous Zinc-Ion Batteries
The SI contains the experimental methods, figures and tables for the main manuscript.


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.