A High-Energy Room-Temperature Sodium-Sulfur Battery

Employing small sulfur molecules as the active cathode component for room‐temperature Na‐S batteries, reveals a novel mechanism that is verified for the batteries' electrochemistry. The sulfur cathode enables a complete two‐electron reaction to form Na2 S, bringing a tripled specific capacity and an increased specific energy compared with traditional high‐temperature Na‐S batteries. At the same time, it offers better cycling stability endowing the batteries with a longer lifespan.