Liquefied gas electrolytes enable low temperature operation due to their low freezing point. However, their high vapor pressure poses a safety concern. Can confinement of these gas electrolytes in a nanoscale material enhance electrochemical performance while minimizing the hazards?

• Constructing hierarchical assemblies of microporous metal-organic framework (MOF)-polymer membranes following a “brick and mortar” approach.
• Performing computational modeling of microcapillary condensation of gas electrolytes in the strong confinement regime of sub-nanometer pores.
• Materials show uptake of hydrofluorocarbon gas molecules at pressures substantially lower than the bulk counterpart.
• Unique ionic properties of the material enable significantly higher energy density at -40 °C compared with conventional electrolytes.