Construction of asymmetric flexible-solid state supercapacitors based on Mo-MnO2 nanoflowers and MoO3-x nanobelts

• DOI: 10.1016/j.surfin.2021.101502
• Publication Date: 2021-10-06T06:17:05Z
• Authors: Mengyao Shang; Chaohui Xing; Wenlong Ding; Chengde Huang
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

Abstract Pseudocapacitive positive and negative electrode materials have broad application prospects in the construction of asymmetric flexible-solid state supercapacitors (AFSCs). Herein, an AFSC is first constructed based on Mo-doped MnO2 (Mo-MnO2) and oxygen vacancy-rich MoO3-x (P-MoO3-x). The flower-like nanocomposite Mo-MnO2 acquired by the hydrothermal method provides a large number of reactive sites, exhibiting a superior specific capacitance of 364.5 F/g at 5 mV/s. P-MoO3-x nanobelts are obtained by a hydrothermal method combined with annealing treatment, in which NaH2PO2 is used as a reductant, resulting in a specific capacitance up to 399.9 F/g. Our fabricated AFSC with the Mo-doped MnO2 and MoO3-x nanocomposite as positive and negative electrode materials, respectively, exhibits a high energy density (95.76 Wh/kg) and high-power density (6.48 kW/kg), and it is expected to be applied in the field of flexible electronics. The density functional theory (DFT) calculation results show that the doping of Mo and the oxygen vacancies can adjust the electronic structure and the local chemical environment of the material. These are beneficial for improving the electrochemical performance.