Ion-channel aligned gas-blocking membrane for lithium-air batteries

Abstract: Lithium-metal-based batteries, owing to the extremely high specific energy, have been attracting intense interests as post-Li-ion batteries. However, the consumption/de-activation of lithium metal can be accelerated when O2 or S used in the cathode crossovers to the metal, which is one of the most significant drawbacks for long-lasting operation of the system. In use of ceramic solid state electrolyte (SSE) separator, despite the capability of gas blocking, thick and heavy plates (~0.3 mm) are necessitated to compensate its mechanical fragility, which ruin the high specific energy of the batteries. Here, we demonstrate fabrication of a new membrane, consisting of micron-sized SSE particles as Li-ion channels embedded in polymer matrix, which enable both high Li-ion conduction and gas-impermeability. Bimodal surface-modification controls the energy of the particle/polymer interface, which consequently allows the channel formation via a simple one-step solution process. The pragmatic cell with the new membrane provides a cell-specific energy of over 500 Wh kg-1, being one of the highest density cell ever reported.