基于碳纳米管纤维生长锌钴双金属氧化物纳米线森林的高能量纤维状超级电容器（英文）

A high energy density fiber-shaped supercapacitor based on zinc-cobalt bimetallic oxide nanowire forests on carbon nanotube fibers

随着可穿戴电子器件的发展,新型纤维状超级电容器逐渐成为最新一代储能器件。然而,纤维状超级电容器较低的电导率和较小的比电容限制了其在高能量密度器件中的应用。本工作采用水热法在碳纳米管纤维表面生长锌钴双金属氧化物纳米线森林设计高能量纤维状超级电容器,利用锌钴双金属氧化物和碳纳米管纤维的协同效应显著提高复合纤维的电化学性能。使用聚氯乙烯薄膜和聚乙烯醇/氯化锂凝胶电解质与复合纤维组装全固态纤维状对称超级电容器,并测试其电化学性能。组装的复合纤维比电容达到112.67 mF·cm^-2,功率密度0.45 mw·cm^-2时的能量密度为12.68μwh·cm^-2。复合纤维有较好的循环稳定性,以1 mA·cm^-2的电流密度进行10 000次循环,其电容保持率为90.63%。此外,在几种不同弯曲角度下,循环伏安曲线的变化可以忽略不计,说明复合纤维具有良好的柔韧性和力学稳定性。全固态纤维状超级电容器的优异性能为便携式和可穿戴电子产品的发展提供了新的机遇。

Zn-Co bimetallic oxide(ZCO) nanowire forests were grown on carbon nanotube(CNT) fibers by a hydrothermal method and the resulting hybrid fiber was used to construct an all solid high energy density fiber-shaped supercapacitor(FSSC). Results indicated that the electrochemical performance of the hybrid fiber was greatly improved due to a synergistic effect between ZnOx, CoOx and the CNT fiber. The ZnOx and CNTs are electrically conductive species that increase the utilization rate of the pseudocapacitive CoOx while the acid-oxidized CNTs provide active sites for the growth of high-density aligned ZCO nanowire forests. The hybrid fiber reaches a high capacitance of 112.67 mF·cm^-2 and an energy density of 12.68 μwh·cm^-2 at a power density of 0.45 mw·cm^-2. Its capacitance retention is 90.63% after 10,000 cycles at a current density of 1 mA·cm^-2, showing good cycling stability. The changes in the cyclic voltammetry curve and capacitance at several different bending angles are negligible, indicating its excellent flexibility and mechanical stability. These outstanding features of the FSSC are attractive for developing portable and wearable electronic devices.