Unlocking the potential of high-voltage aqueous rechargeable batteries: Achievements and perspectives

As an emerging technology for energy storage, aqueous rechargeable batteries possess several advantages including intrinsic safety, low cost, high power density, environmental friendliness, and ease of manufacture. Consequently, they hold significant application value and promising prospects in the field of large-scale energy storage, garnering extensive attention and experiencing rapid development in recent years. However, the limited voltage window poses a significant challenge for further advancements of the aqueous rechargeable batteries. Substantial progress has been made in achieving wide voltage windows (>2.0 V) and large operating voltages for aqueous rechargeable batteries. This mini-review paper presents an overview of the theoretical mechanisms governing stabilized voltage windows, providing essential guidelines for expanding the voltage range of aqueous rechargeable batteries. The strategies for constructing high-voltage aqueous rechargeable batteries are subsequently summarized and categorized into anode selection, cathode engineering, and electrolyte optimization strategies. By discussing their current research status along with associated challenges and potential solutions, we also suggest a few research directions for high-voltage aqueous rechargeable batteries.