Sodium-Sulfur Batteries with a Polymer-Coated NASICON-type Sodium-Ion Solid Electrolyte

The shuttling of dissolved sodium polysulfides through conventional porous separators has been a challenging issue with the development of room temperature sodium-sulfur (RT Na-S) batteries. In this study, a NASICON-type Na+-ion solid-electrolyte membrane, Na3Zr2Si2PO12, is used as a polysulfide-shield separator. However, as a general issue with solid-electrolyte batteries, the ionic interface between the Na-metal anode and the Na-ion conduction Na3Zr2Si2PO12 membrane is fairly poor. To address this problem, a critical approach by coating a layer of a polymer that exhibits intrinsic nanoporosity (PIN) onto the Na3Zr2Si2PO12 membrane has been developed. The PIN coating greatly improves the ionic interfacial properties between the Na anode and the Na3Zr2Si2PO12 membrane. RT Na-S batteries with a PIN-coated Na3Zr2Si2PO12 solid-electrolyte separator show enhanced cycle life.