Biological cell template synthesis of nitrogen-doped porous hollow carbon spheres/MnO2 composites for high-performance asymmetric supercapacitors. (10th February 2019)

• Record Type: Journal Article
• Authors: Du, Wei; Wang, Xiaoning; Zhan, Jie; Sun, Xueqin; Kang, Litao; Jiang, Fuyi; Zhang, Xiaoyu; Shao, Qian; Dong, Mengyao; Liu, Hu; Murugadoss, Vignesh; Guo, Zhanhu
• Is Part Of: Electrochimica acta. Volume 296(2019)
• Page Start: 907
• Page End: 915
• Publication Date: 2019-02-10
• Subjects: Asymmetric supercapacitor -- Biological cell template -- Carbon material -- Manganese dioxide -- Composite; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.11.074
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Nitrogen-doped porous hollow carbon spheres were fabricated via hydrothermal pre-carbonization and pyrolysis carbonization using yeast cell templates. After that, the MnO2 nanowires were deposited by the in-situ hydrothermal reaction. By controlling the reaction concentration, various MnO2 nanostructures with different morphologies and electrochemical properties were obtained. The as-prepared sample exhibited an ultrahigh specific capacitance of 255 F g -1 at a current density 1 A g -1 in 1 M Na2 SO4 electrolyte. The MnO2 /HCS-30 material was used as the positive electrode, and the HCS was used as the negative electrode to assemble the asymmetric supercapacitor. The maximum energy density operating at the 2.0 V voltage window is 41.4 Wh kg −1 at a power density of 500 W kg −1 and still maintains 23.0 Wh kg −1 at a power density of 7901 W kg −1 . Moreover, it displayed excellent cycle stability, retained approximately 93.9% of the capacitance after 5000 cycles. This work innovatively combines biomass and energy, provides an environmentally benign strategy and new insights for the preparation of electrode materials. Graphical abstract: An asymmetric supercapacitors based on MnO2 @Biological cell template synthesized nitrogen-doped porous hollow carbon spherical composites exhibited high energy and power density and an excellent cycle stability. Image Highlights: N-doped porous hollow carbon spheres were synthesized based on yeast templates. The MnO2 nanowires were anchored by one-step hydrothermal deposition. The prepared composite material exhibited a unique hollow structure. As-prepared asymmetric supercapacitors exhibited excellent capacitive behavior.