# Towards Rechargeable Zinc-Air Batteries with Aqueous Chloride Electrolytes

## TL;DR

This study combines theoretical simulations and experimental tests to evaluate aqueous chloride electrolytes for rechargeable zinc-air batteries, addressing challenges like pH instability and precipitation to improve battery longevity.

## Contribution

It provides new insights into the stability issues of chloride-based electrolytes in ZABs and proposes strategies to enhance their performance and lifespan.

## Key findings

- pH instability observed during operation
- Precipitation of zinc hydroxide chloride confirmed
- Proposed methods to improve electrolyte stability

## Abstract

This paper presents a combined theoretical and experimental investigation of aqueous near-neutral electrolytes based on chloride salts for rechargeable zinc-air batteries (ZABs). The resilience of near-neutral chloride electrolytes in air could extend ZAB lifetime, but theory-based simulations predict that such electrolytes are vulnerable to other challenges including pH instability and the unwanted precipitation of mixed zinc hydroxide chloride products. In this work, we combine theory-based simulations with experimental methods such as full cell cycling, operando pH measurements, ex-situ XRD, SEM, and EDS characterization to investigate the performance of ZABs with aqueous chloride electrolytes. The experimental characterization of near-neutral ZAB cells observes the predicted pH instability and confirms the composition of the final discharge products. Steps to promote greater pH stability and control the precipitation of discharge products are proposed.