Flash Nitrogen‐Doped Carbon Nanotubes for Energy Storage and Conversion

Abstract In recent years, nitrogen‐doped carbons show great application potentials in the fields of electrochemical energy storage and conversion. Here, the ultrafast and green preparation of nitrogen‐doped carbon nanotubes (N‐CNTs) via an efficient flash Joule heating method is reported. The precursor of 1D core–shell structure of CNT@polyaniline is first synthesized using an in situ polymerization method and then rapidly conversed into N‐CNTs at ≈1300 K within 1 s. Electrochemical tests reveal the desirable capacitive property and oxygen catalytic activity of the optimized N‐CNT material. It delivers an improved area capacitance of 101.7 mF cm −2 at 5 mV s −1 in 1 m KOH electrolyte, and the assembled symmetrical supercapacitor shows an energy density of 1.03 µWh cm −2 and excellent cycle stability over 10 000 cycles. In addition, the flash N‐CNTs exhibit impressive catalytic performance toward oxygen reduction reaction with a half‐wave potential of 0.8 V in alkaline medium, comparable to the sample prepared by the conventional long‐time pyrolysis method. The Zn–air battery presents superior charge–discharge ability and long‐term durability relative to commercial Pt/C catalyst. These remarkable electrochemical performances validate the superiorities of the Joule heating method in preparing the heteroatom‐doped carbon materials for wide applications.