The electrochemical performance of metal−air batteries is sensitive to environmental humidity, which significantly limits its wide application in an air environment. In this paper, a waterproof and breathable polydimethylsiloxane (PDMS) composite membrane has been successfully synthesized by the water spreading method for metal−air batteries. The effects of spreading times and fillers (hydrophobic SiO 2 and silicalite-1) on the water vapor and air permeability of the PDMS membrane were investigated. The results demonstrate that increasing the spreading times and adding an appropriate amount of hydrophobic SiO 2 can improve the waterproof quality and air permeability of the PDMS membrane. The optimized membrane was assembled into a metal−air battery, and the effects of the membrane on the running resistance, cycle number, and polarization voltage of the battery were evaluated. The hydrophobic SiO 2 −PDMS membrane significantly reduces the running resistance of the battery and improves the cycle number of lithium−air batteries by 25% and that of zinc−air batteries by 100% in an air environment (40% RH, 25 °C). The polarization voltage is also significantly reduced, indicating great potential in applications.

No abstract

No abstract