Scholarlink

<p>Expanding the stable voltage window and specific capacitance of supercapacitor electrode materials remains a key scientific challenge due to the low energy density of supercapacitors. In this study, starting from the problem of low specific capacitance caused by the limited electron transfer rate due to the low conductivity of MnO<sub>2</sub>, a simple and economical hydrothermal method was used to doping different contents of Nb<sup>5+</sup> ions, which replaced some Mn<sup>4+</sup> ions in the α-MnO<sub>2</sub> lattice, thereby causing certain changes in the charge density and band structure of α-MnO<sub>2</sub>, and effectively improving its conductivity. In addition, Nb<sup>5+</sup>-doped α-MnO<sub>2</sub> effectively alters its morphology and surface area, providing a large surface area for ion and electron transport. The optimized Nb-MnO<sub>2</sub> electrode has a voltage window widened from 0.8&#xa0;V to 1.2&#xa0;V in a 1&#xa0;M Na<sub>2</sub>SO<sub>4</sub> electrolyte, with a specific capacitance of 587 F/g with in the 1.2&#xa0;V wide voltage window, while the undoped MnO<sub>2</sub> has a specific capacitance of only 131 F/g. A 2&#xa0;V asymmetric supercapacitor is constructed with activated carbon AC as the negative electrode, providing a high energy density of 57 Wh/kg at a power density of 1010 W/kg in a 3&#xa0;M KOH electrolyte. In addition, at a current density of 5 A/g, the capacitance retention rate of 84.85% was maintained after 5000 charge–discharge cycles. This work is a valuable foundation for the future exploration of wide voltage window and high-performance aqueous electrolyte asymmetric supercapacitors.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

One-step hydrothermal synthesis of Nb5+-doped α-MnO2 nanoparticle for high-performance asymmetric supercapacitor electrode material

  • 期刊论文

  • 发表日期：

    2026年4月10日

查看全文
  • Yongyuan Wang,
  • Xuyin Li,
  • Chaoyong Xu,
  • Jianchun Cao

摘要

Expanding the stable voltage window and specific capacitance of supercapacitor electrode materials remains a key scientific challenge due to the low energy density of supercapacitors. In this study, starting from the problem of low specific capacitance caused by the limited electron transfer rate due to the low conductivity of MnO2, a simple and economical hydrothermal method was used to doping different contents of Nb5+ ions, which replaced some Mn4+ ions in the α-MnO2 lattice, thereby causing certain changes in the charge density and band structure of α-MnO2, and effectively improving its conductivity. In addition, Nb5+-doped α-MnO2 effectively alters its morphology and surface area, providing a large surface area for ion and electron transport. The optimized Nb-MnO2 electrode has a voltage window widened from 0.8 V to 1.2 V in a 1 M Na2SO4 electrolyte, with a specific capacitance of 587 F/g with in the 1.2 V wide voltage window, while the undoped MnO2 has a specific capacitance of only 131 F/g. A 2 V asymmetric supercapacitor is constructed with activated carbon AC as the negative electrode, providing a high energy density of 57 Wh/kg at a power density of 1010 W/kg in a 3 M KOH electrolyte. In addition, at a current density of 5 A/g, the capacitance retention rate of 84.85% was maintained after 5000 charge–discharge cycles. This work is a valuable foundation for the future exploration of wide voltage window and high-performance aqueous electrolyte asymmetric supercapacitors.