A ternary B, N, P-Doped carbon material with suppressed water splitting activity for high-energy aqueous supercapacitors

Porous carbon materials (PCMs) have been extensively investigated as electrode materials for super-capacitors, yet are severely hindered by low capacitance and energy density. Herein, we reported the efficient synthesis of a ternary B, N, P-doped PCM (termed as BNP-C) via polymer dehalogenation strategy. The atomic contents of B, N, and P, as characterized by XPS, are 11.5, 1.1, and 0.8%, respectively, yet intriguingly resulting in limited water splitting activity due to the overwhelmingly presented B dopant. This specific feature can be taken advantage of for effectively expanding the workable voltage window while maintaining large capacitances of aqueous supercapacitors (ASCs). Besides, the BNP-C exhibited porous 3D structure, hierarchical porous structure, and large specific surface area of 1118.5 m(2) g(-1), which simultaneously ensured the BNP-C-assembled ASC with superior capacitive performance. As confirmed by both Dunn and Trasatti methods, pseudocapacitance remarkably contributed similar to 44.9 and similar to 40.2% respectively in overall capacitances for the BNP-C, which was mainly credited to the heavy decoration of B. In addition, the BNP-C symmetric ASC delivered very good long-term stability and high specific energy of 12.0 and 10.9 Wh kg(-1) in acidic and alkaline electrolytes, respectively. (C) 2020 Elsevier Ltd. All rights reserved.