Low-Cost, Sustainable Hybrid Aqueous Zinc Metal Batteries Using Ethyl Cellulose as a Binder

Despite their inherently lower energy density than lithium-ion batteries (LIBs), aqueous zinc metal batteries (AZMBs) have recently attracted interest as rechargeable energy storage devices due to their low cost and high operational and environmental safety. They are composed of metallic zinc as the anode, an aqueous zinc salt electrolyte and a cathode capable of (de)intercalating Zn2+ ions upon its (oxidation) reduction reaction. In this work, we studied a hybrid AZMB in which a dual-ion electrolyte containing both Zn2+ and Li+ ions was used in conjunction with a Li+ ion intercalation cathode, i.e., LiFePO4 (LFP), one of the most common, reliable, and cheap cathodes for LIBs. In this study, we present evidence that, thanks to its insolubility in water, ethyl cellulose (EC) can be effectively utilized as a binder for cathode membranes in AZMBs. Furthermore, its solubility in alcohol provides a significant advantage in avoiding the use of toxic solvents, contributing to a safer and more environmentally friendly approach to the formulation process.