Sandwich Structure Corrosion-Resistant Current Collector for Aqueous Batteries

Current collector corrosion in the aqueous electrolyte is a critical but easily overlooked issue impacting the cycling life, efficiency, and capacity utilization of aqueous batteries. So far, there is no metal-based current collector intrinsically stable in the aqueous electrolyte due to the highly corrosive aggressive nature of the aqueous environment. Thus, it is critical to find an easy-made, lightweight, commercially available, and extremely corrosion-resistant current collector for aqueous batteries. Here, we designed a corrosion-resistant and easy-made current collector with the carbon black/polyethylene composite (CBPE)-metal-CBPE (CMC) sandwich structure, including the CBPE in the outer layer as the waterproof layer and the superior electronic conducting metal in the inner layer offering a fast electronic pathway. Combining carbon and metal, our CMC current collector has not only superior corrosion-resistance against the aqueous electrolyte but also high electronic conductivity comparable to the current metal collector, which is favorable to improve the electrochemical performance of aqueous Li-ion batteries.