Enhanced cycling stability of Li–O2 batteries by using a polyurethane/SiO2/glass fiber nanocomposite separator

Abstract

A considerable improvement in the cycle performance of aprotic Li–O₂ batteries was achieved by using a polyurethane/SiO₂ gel nanoparticles/glass fiber (PU/SiO₂/GF) nanocomposite separator, where a persistent capability of 1000 mA h g⁻¹ was maintained for at least 300 charge/discharge cycles in a DMSO electrolyte with 1 M LiClO₄ and 0.05 M LiI. In comparison, the cell with a conventional GF separator in the same experimental setup only run for 60 cycles. SEM, XRD and FT-IR analyses indicate that the corrosion and dendritic growth of the Li anode were significantly inhibited during the charge/discharge cycling, and the eventual failure of the Li–O₂ batteries was attributed to the cathode passivation caused by the accumulation of the discharge product, which blocked the transfer of oxygen and electrolyte to the MWNTs cathode.