Patil Swati J, Chodankar Nilesh R, Huh Yun Suk, Han Young-Kyu, Lee Dong Weon
Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul, 04620, Republic of Korea.
Department of Biological Engineering, Inha University, 100, Inha-ro, Incheon, 22212, Republic of Korea.
ChemSusChem. 2021 Mar 22;14(6):1602-1611. doi: 10.1002/cssc.202002968. Epub 2021 Feb 17.
Nanofabrication of heteroatom-doped metal oxides into a well-defined architecture via a "bottom-up" approach is crucial to overcome the boundaries of the metal oxides for energy storage systems. In the present work, this issue was addressed by developing sulfur-doped bimetallic cobalt tungstate (CoWO ) porous nanospheres for efficient hybrid supercapacitors via a single-step, ascendable bottom-up approach. The combined experimental and kinetics studies revealed enhanced electrical conductivity, porosity, and openness for ion migration after amendments of the CoWO via sulfur doping. As a result, the sulfur-doped CoWO nanospheres exhibited a specific capacity of 248.5 mA h g with outstanding rate capability and cycling stability. The assembled hybrid supercapacitor cell with sulfur-doped CoWO nanospheres and activated carbon electrodes could be driven reversibly in a voltage of 1.6 V and exhibited a specific capacitance of 177.25 F g calculated at 1.33 A g with a specific energy of 63.41 Wh kg at 1000 W kg specific power. In addition, the hybrid supercapacitor delivered 94.85 % initial capacitance over 10000 charge-discharge cycles. The excellent supercapacitive performance of sulfur-doped CoWO nanospheres may be credited to the sulfur doping and bottom-up fabrication of the electrode materials.
通过“自下而上”的方法将杂原子掺杂的金属氧化物制备成结构明确的体系对于突破金属氧化物在储能系统中的局限至关重要。在本工作中，通过一步可扩展的自下而上方法制备了用于高效混合超级电容器的硫掺杂双金属钨酸钴（CoWO₄）多孔纳米球来解决这一问题。结合实验和动力学研究表明，通过硫掺杂对CoWO₄进行改性后，其导电性、孔隙率以及离子迁移的开放性均得到增强。结果，硫掺杂的CoWO₄纳米球表现出248.5 mA h g⁻¹的比容量，具有出色的倍率性能和循环稳定性。由硫掺杂的CoWO₄纳米球和活性炭电极组装而成的混合超级电容器在1.6 V电压下可实现可逆驱动，在1.33 A g⁻¹电流密度下计算得到的比电容为177.25 F g⁻¹，在1000 W kg⁻¹的比功率下比能量为63.41 Wh kg⁻¹。此外，该混合超级电容器在10000次充放电循环后仍保持94.85%的初始电容。硫掺杂CoWO₄纳米球优异的超级电容性能可能归功于硫掺杂以及电极材料的自下而上制备。
