Acidified Nitrogen Self‐Doped Porous Carbon with Superprotonic Conduction for Applications in Solid‐State Proton Battery

Solid proton electrolytes play a crucial role in various electrochemical energy storage and conversion devices. However, the development of fast proton conducting solid proton electrolytes at ambient conditions remains a significant challenge. In this study, a novel acidified nitrogen self‐doped porous carbon material is presented that demonstrates exceptional superprotonic conduction for applications in solid‐state proton battery. The material, designated as MSA@ZIF‐8‐C, is synthesized through the acidification of nitrogen‐doped porous carbon, specifically by integrating methanesulfonic acid (MSA) into zeolitic imidazolate framework‐derived nitrogen self‐doped porous carbons (ZIF‐8‐C). This study reveals that MSA@ZIF‐8‐C achieves a record‐high proton conductivity beyond 10−2 S cm−1 at ambient condition, along with good long‐term stability, positioning it as a cutting‐edge alternative solid proton electrolyte to the default aqueous H2SO4 electrolyte in proton batteries. A new family of solid proton electrolytes is prepared through the integration of acidic molecular species into nitrogen self‐doped porous carbon. These new solid proton electrolytes exhibit record‐high proton conduction beyond 10−2 S cm−1 at ambient condition and hold great promise as an electrolyte for solid‐state proton batteries.