Fabrication of electrospun CO2 adsorption membrane for zinc-air battery application

Zinc-air batteries (ZABs) are an important option for energy storage applications because of their high specific capacity. However, when ZABs are operated in ambient air, the CO2 (400 ppm) in the air can react with the alkaline electrolyte, forming carbonates, which shorten the battery lifetime. In this work, we fabricated an electrospun polystyrene (PS)/polyethylenimine (PEI) fiber membrane to capture CO2 from ambient air before the air is admitted into a ZAB to enhance battery performance. The result show that the PS/PEI fibers have a CO2 adsorption capacity of 3.42 mmol(CO2)/g(adsorbent) or 7.58 mmol(CO2)/g(PEI) at room temperature. The fibers retain 91% of their initial CO2 adsorption capacity after 15 cycles of the adsorption-desorption process. A ZAB cell equipped with PS/PEI fibers exhibited a better discharge capacity (802 mA h/g) compared to that of a ZAB without the fibers (762 mA h/g).