Effect of calcination temperature on the microstructure of vanadium nitride/nitrogen-doped graphene nanocomposites as anode materials in electrochemical capacitors†,Inorganic Chemistry Frontiers

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Effect of calcination temperature on the microstructure of vanadium nitride/nitrogen-doped graphene nanocomposites as anode materials in electrochemical capacitors†
Inorganic Chemistry Frontiers ( IF 6.1 ) Pub Date : 2018-11-14 00:00:00 , DOI: 10.1039/c8qi01071d
Jinghua Liu _{1,

2,

3,

4,

5} , Fengfan Li _{1,

2,

3,

4,

5} , Weiwei Liu _{1,

2,

3,

4,

5} , Xin Li _{1,

2,

3,

4,

5}

Affiliation

Hybrid vanadium nitride/N-doped graphene (VN/N-Gr) nanocomposites have been recently used as anode materials in electrochemical capacitors. The electrochemical performances of electrode materials are dependent on their microstructures, which in turn are dependent on the fabrication methods and conditions. In this study, VN/N-Gr nanocomposites were fabricated by an in situ method by pyrolysis of a mixture of dicyandiamide, glucose, and vanadium(IV) oxide sulfate hydrate under a N₂ atmosphere. The effect of calcination temperature on the microstructure of the as-prepared products was systematically investigated. It is found that calcination temperature can greatly influence the structure, VN_xO_y and doping N content of VN/N-Gr, as well as the corresponding electrochemical performance. As an electrochemical capacitor electrode, the VN/N-Gr nanocomposite prepared at 700 °C exhibits a high specific capacitance of 342.1 F g⁻¹ at 0.5 A g⁻¹ in a 2 M KOH aqueous electrolyte with a wide operation window from −1.0 to 0.2 V. Furthermore, the assembled symmetrical device delivers an energy density of 10.3 W h kg⁻¹ at a power density of 276.3 W kg⁻¹ and remains 7.6 W h kg⁻¹ at a power density of 5484.2 W kg⁻¹. The findings in this work suggest that a judicious choice of calcination temperature during the pyrolysis process could improve the performances of electrode materials and the corresponding devices.

中文翻译：

煅烧温度对氮化钒/掺氮石墨烯纳米复合材料作为电化学电容器阳极材料的微观结构的影响†

混合氮化钒/ N掺杂石墨烯（VN / N-Gr）纳米复合材料最近已被用作电化学电容器中的阳极材料。电极材料的电化学性能取决于其微观结构，而微观结构又取决于制造方法和条件。在这项研究中，VN / N-Gr纳米复合材料是通过在N ₂气氛下将双氰胺，葡萄糖和硫酸钒（IV）氧化物水合物的混合物热解的原位方法制备的。系统地研究了煅烧温度对所制备产品的微观结构的影响。发现煅烧温度可以极大地影响结构，VN _x O _yVN / N-Gr的掺杂N含量以及相应的电化学性能。作为电化学电容器电极，在700°C下制备的VN / N-Gr纳米复合材料在2 M KOH水性电解质中在0.5 A g ^-1下表现出342.1 F g ^-1的高比电容，其宽操作窗口为-1.0至0.2V。此外，组装的对称装置在276.3 W kg ^-1的功率密度下提供了10.3 W h kg ^-1的能量密度，并在5484.2 W kg ^-1的功率密度下保持了7.6 W h kg ^-1的能量密度。。这项工作的发现表明，在热解过程中明智地选择煅烧温度可以改善电极材料和相应器件的性能。

更新日期：2018-11-14

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