Aqueous batteries have several advantages over their non-aqueous counterparts, including low cost, safety, high ionic conductivity, and environmental friendliness. However, they face three main challenges:
Higher operating voltage for the cathode
Aqueous electrolytes have a narrower electrochemical stability window compared to non-aqueous electrolytes, limiting the voltage that can be achieved with the cathode. Researchers are exploring new cathode materials and electrolyte compositions to increase the operating voltage.
More stable metal anode interface
The metal anode, such as zinc or lithium, can react with the aqueous electrolyte, leading to unwanted side reactions and poor cycling performance. Developing strategies to stabilize the metal-electrolyte interface is crucial for improving the anode’s performance and cycle life.
Larger electrochemical stability window of the electrolyte
The limited electrochemical stability window of aqueous electrolytes restricts the choice of electrode materials and reduces the overall energy density of the battery system. Researchers are investigating new electrolyte formulations and additives to widen the stability window.