线状全固态CNTF@ZnCo-OH//CNTF@RGO超级电容器的制备与电化学性能

采用电化学沉积在碳纳米管纤维上复合锌钴氢氧化物纳米片（CNTF@ZnCo-OH），并研究其电化学性能。实验结果表明CNTF@ZnCo-OH电极在2 A·g^-1的电流密度下比电容为748 F·g^-1，在10 A·g^-1的电流密度下循环2 000圈以后，比电容保持率高达110.4%。该优异循环性能得益于碳纳米管纤维基底的网络结构和ZnCo-OH的纳米片状结构。以CNTF@RGO（石墨烯）为负极、CNTF@ZnCo-OH为正极，组装线状全固态非对称CNTF@ZnCo-OH//CNTF@RGO超级电容器。该器件在0.5 A·g^-1电流密度下比电容为70 F·g^-1，2 000次循环后电容保持率为79.6%，并且在不同的弯曲状态下保持电化学性能不变，具有优良的机械稳定性。该非对称线状器件可以在0.8~1.4 V之间工作，其能量密度高达19.1 Wh·kg^-1，对应的功率密度为1 400.3 W·kg^-1。2个30 mm长的线状器件可持续点亮LED灯10 s。

Preparation and Electrochemical Property of Linear All-Solid-State Supercapacitor Based on CNTF@ZnCo-OH//CNTF@RGO Composite

Zinc cobalt double hydroxide nanosheets (CNTF@ZnCo-OH) were grown on carbon nanotube fibers via electrochemical deposition technique and their electrochemical performance was investigated. The experimental results show that the CNTF@ZnCo-OH electrode delivers high specific capacitance which can reach 748 F·g^-1 at a current density of 2 A·g^-1. After 2 000 cycles at 10 A·g^-1, 110.4% of initial specific capacitance was maintained. This excellent cycling performance is attributed to the network structure of carbon nanotube fiber substrate and ZnCo-OH nanosheet structure. Subsequently, a linear all-solid asymmetric CNTF@ZnCo-OH//CNTF@RGO (graphene) supercapacitor was assembled using CNTF@RGO and CNTF@ZnCo-OH as negative and positive electrodes, respectively. The device exhibits good electrochemical performance with specific capacitance of 70 F·g^-1 at a current density of 0.5 A·g^-1. The capacitance retention rate was 79.6% after 2 000 cycles. In addition, the device shows mechanical stability because its electrochemical performance remains unchanged under different bending states. The asymmetric linear device can work in the voltage window of 0.8~1.4 V and its energy density can reach 19.1 Wh·kg^-1, corresponding to a power density of 1 400.3 W·kg^-1. Two 30 mm long linear devices can continuously light the LED for 10 s.