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

Abstract 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 H 2 SO 4 electrolyte in proton batteries.