Zinc oxide/carbon nanotube nanocomposite for high-performance flexible supercapacitor with sensing ability

Abstract In recent decades, the development and optimization of supercapacitors have garnered a great deal of attention for the reason that it is a promising method to store energy and supply power to the wireless sensors and portable electronics. Therefore, carbon nanotube (CNT) and zinc oxide (ZnO) based supercapacitors are reported in this paper for high-performance energy storage. The electrodes with different contents of ZnO and CNT are obtained by orderly depositing carbon nanofiber (CNF), ZnO and CNT nano-materials on tissue substrates through the method of suction filtration. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and electrochemical testing are carried out in the experiments to characterize the composition, morphology and electrochemical performance of the electrodes. Results show that the increase in the content of CNT will enhance capacitive performance. While for ZnO, the capacitive performance of the electrodes will firstly increase and then decrease with the increase of the content. Furthermore, the largest areal capacitance obtained in the experiment at a scan rate of 50 mV/s is 14.6 mF/cm2. Finally, the sensing ability of the electrode is demonstrated by output voltage under finger tapping testing due to the piezoelectricity of ZnO.