Electrochemical Performance of Nitrogen-Doped Carbons: From Fundamental Studies to Practical Pouch Device

Abstract

Nitrogen-doped carbide-derived carbons (N-CDCs) are promising materials for energy storage due to their tunable structure and chemistry. Here, we design a molecular architecture strategy to promote nitrogen incorporation and microstructural control during the synthesis of N-CDCs. By varying polymerization and pyrolysis conditions, we obtain materials with hierarchical porosity and high specific surface area (S_BET > 2000 m² g⁻¹) and nitrogen content between 1.8 and 6.4 wt.%. Electrochemical evaluation in aqueous 6 M KOH using both three- and two-electrode configurations, identifies nitrogen doping, defect density, and hierarchical porosity as key contributors to performance. The optimized N-CDC delivers a specific capacitance of 210 F g⁻¹ at 1 A g⁻¹, with high retention at elevated current densities. A proof-of-concept pouch cell shows 100 F g⁻¹ at 0.5 A g⁻¹ and stable cycling over 5000 cycles, resulting in superior coulombic efficiency. The practical applicability is demonstrated with two pouch cells connected in series to power an electronic watch (1.5 V). These findings demonstrate the effectiveness of molecular-level control in the design of high-performance carbon-based supercapacitor electrodes.