Li Sa, Feng Ruichao, Li Mai, Zhao Xuan, Zhang Beihe, Liang Yuan, Ning Huanpo, Wang Jiale, Wang Chunrui, Chu Paul K
College of Science, Donghua University Shanghai 201620 People's Republic of China
Department of Materials Processing and Control Engineering, University of Science and Technology Beijing 30 Xueyuan Road, Haidian District Beijing 100083 People's Republic of China.
RSC Adv. 2020 Oct 12;10(61):37489-37499. doi: 10.1039/d0ra07307e. eCollection 2020 Oct 7.
A nanoscale core-shell NiO@CoO composite is prepared on flexible carbon cloth for electrodes in supercapacitors and overall water splitting. The needle-like CoO nanowires with NiO nanosheets as the active materials improve the elemental constituents as well as surface area. The NiO@CoO electrode boasts a capacity of 2.87 F cm (1024.05 F g) at 1 A g current density, and even at a large current density of 20 A g the retention ratio is 80.9% after 5000 cycles. The excellent specific capacity with high rate capability can be ascribed to the unique structure which increases the area of the liquid-solid interface and facilitates electron and ion transport, improving the utilization efficiency of active materials. The asymmetric hybrid supercapacitor prepared with the core-shell electrode shows the energy output of 40.3 W h kg at 750 W kg with a better retention (71.7%) of specific capacitance after 15 000 cycles. In addition, linear sweep voltammetry is performed to assess the performance of the electrode in water splitting and the electrode shows excellent activity in the OER as manifested by a Tafel slope of 88.04 mV dec. Our results show that the bifunctional structure and design strategy have large potential in energy applications.
在柔性碳布上制备了一种用于超级电容器电极和全水解的纳米级核壳结构NiO@CoO复合材料。以NiO纳米片为活性材料的针状CoO纳米线改善了元素组成和表面积。NiO@CoO电极在1 A g电流密度下的容量为2.87 F cm（1024.05 F g），即使在20 A g的大电流密度下，经过5000次循环后保留率仍为80.9%。优异的比容量和高倍率性能可归因于其独特的结构，该结构增加了液固界面面积，促进了电子和离子传输，提高了活性材料的利用效率。用核壳电极制备的不对称混合超级电容器在750 W kg时的能量输出为40.3 W h kg，经过15000次循环后比电容保持率较好（71.7%）。此外，通过线性扫描伏安法评估电极在水分解中的性能，电极在析氧反应中表现出优异的活性，塔菲尔斜率为88.04 mV dec。我们的结果表明，这种双功能结构和设计策略在能源应用中具有巨大潜力。
