One-step fabrication of biomass-derived hierarchically porous carbon/MnO nanosheets composites for symmetric hybrid supercapacitor

• Published in: Applied surface science 2020-10, Vol.526, p.146696, Article 146696
• Main Authors: Zhao, Ning, Deng, Libo, Luo, Dawei, Zhang, Peixin
• Format: Article
• Language: English
• Subjects: Biomass-derived porous carbon; Manganese monoxide; Supercapacitor; Symmetric hybrid supercapacitor
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2020.146696

[Display omitted] •HPC-MnO composite materials are synthesized by a facile synchronous activation and loading approach.•HPC-MnO materials can serve both as the positive and negative electrodes in symmetric hybrid supercapacitor.•Promising electrochemical performances were received for the symmetric HPC-MnO//HPC-MnO device.•Synergistic effects between EDLC from HPC and pseudocapacitance from redox reaction of MnO were revealed. In this work, hierarchically porous carbon/manganese monoxide nanosheets (HPC-MnO) composite materials are synthesized by a facile one-step approach, in which chemical activation of biomass precursor (wasted litchi shell) and loading of MnO nanosheets are conducted synchronously. The phase structure, chemical composition, morphology and specific surface area as well as the pores distribution are investigated for the resultant HPC-MnO composite materials. Interestingly, the as obtained HPC-MnO composite materials can serve both as the positive and negative electrodes simultaneously in a hybrid symmetric supercapacitor. High specific capacitances of 162.7F/g at a current density of 0.5 A/g and energy density of 57.7 W h/kg at a power density of 400 W/kg are obtained for the assembled symmetric HPC-MnO//HPC-MnO device, owing to the synergistic effects between electrochemical double-layer capacitance from the hierarchical porous carbons and pseudocapacitance from the redox reaction of manganese oxides. This work provides a facile and scalable strategy to synthesize carbon/metal oxides composites with promising electrochemical performances application for energy storage devices and opens a new gateway to design novel symmetric hybrid supercapacitors.