Mixed-valent MnSiO3/C nanocomposite for high-performance asymmetric supercapacitor

• Published in: Journal of colloid and interface science Vol. 556; pp. 239 - 248
• Main Authors: Li, Bin, Zhang, Xihua, Hu, Cheng, Dou, Jinhe, Xia, Guang, Zhang, Pengxiang, Zheng, Zhiqiang, Pan, Yaokun, Yu, Huijun, Chen, Chuanzhong
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15.11.2019
• Subjects: Carbon coating; Cycling stability; Hierarchical porous; Manganese silicate; Pseudocapacitive; Valence state; Hierarchical porous; Cycling stability; Valence state; Pseudocapacitive; Carbon coating; Manganese silicate
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2019.08.054

[Display omitted] In this work, carbon-coated manganese silicate (MnSiO3/C) nanocomposite with excellent cycling stability was fabricated via a cost-effective process. The carbon coating followed with a CO2 heat treatment process on the manganese silicate results in mixed-valent hierarchically-porous nanoparticles, which tightly connects with an ultrathin (∼1.5 nm) and ordered carbon coating layer. This composite features rectangular-like cyclic voltammetry curve with two couples of redox peaks, suppressing the irreversible reactions and thus providing a broad and stable working voltage. By fitting the CV curves, the MnSiO3/C demonstrates a capacitive energy-storage behavior. The as-assembled activated carbon//MnSiO3/C asymmetric supercapacitor in 1 M Na2SO4 aqueous electrolyte is found to have excellent cycling stability, with 95.5% retention of initial after 10,000 cycles. This device could deliver 25.8 W h kg−1 energy density at the power density of 1 kW kg−1 with ∼10 mg cm−2 high mass loading, suggesting a bright prospect in practical application.