Boosting the Capacitive Performance of Supercapacitors by Hybridizing N, P-Codoped Carbon Polycrystalline with...

Chitosan, a biomass raw material, was utilized as a carbon skeleton source and served as a nitrogen (N) atom dopant in this study. By co-doping phosphorus (P) atoms from H₃PO₄ and nitrogen (N) atoms with a carbon (C) skeleton and hybridizing them with Mn₃O₄ on a carbon fiber cloth (CC), an Mn₃O₄@NPC/CC electrode was fabricated, which exhibited an excellent capacitive performance. The N, P-codoped carbon polycrystalline material was hybridized with Mn₃O₄ during the chitosan carbonization process. This carbon polycrystalline structure exhibited an enhanced conductivity and increased mesopore content, thereby optimizing the micropore/mesopore ratio in the electrode material. This optimization contributed to the improved storage, transmission, and diffusion of electrolyte ions within the Mn₃O₄@NPC electrode. The electrochemical behavior was evaluated via cyclic voltammetry and galvanostatic charge-discharge tests using a 1 M Na₂SO₄ electrolyte. The capacitance significantly increased to 256.8 F g^-1 at 1 A g^-1, and the capacitance retention rate reached 97.3% after 5000 charge/discharge cycles, owing to the higher concentration of the P-dopant in the Mn₃O₄@NPC/CC electrode. These findings highlight the tremendous potential of flexible supercapacitor electrodes in various applications.