Unconventional Designs for Functional Sodium-Sulfur Batteries

Sodium-sulfur (Na–S) batteries that utilize earth-abundant materials of Na and S have been one of the hottest topics in battery research. The low cost and high energy density make them promising candidates for next-generation storage technologies as required in the grid and renewable energy. In recent years, extensive efforts have been devoted to the diversity and functionalities of Na–S batteries, aiming to extend their potential applications across multiple temporal and spatial dimensions. Here, we summarize the unconventional designs for the functionalities of Na–S batteries such as flexible batteries, solid-state cells, flame resistance, and operation at extreme temperatures. By highlighting these design strategies that help to realize the functionalities, we hope this review offers a pathway to foster the bright future of Na–S batteries in diverse applications.