Reliability study of hydrogel-based flexible supercapacitor

With the development of electronic technology, wearable devices are growing rapidly. The energy devices matching the power supply requirement of wearable devices with flexibility property become a hot topic. Flexible supercapacitors are advanced energy devices that present high power density, fast charging rate and bendable characteristic. The flexible supercapacitors are assembled by flexible electrode and electrolyte. The chemical stability of the electrolyte with time and complex environments, such as mechanical stress and variation of temperatures, has to be studied to guarantee a good performance. In this work, a flexible supercapacitor composed of carbon fiber cloth as the electrode and polyvinyl alcohol (PVA) as the electrolyte is prepared. The electrode is activated by laser ablation method. The reliability of the supercapacitor is comprehensively studied in the aspects of electrolyte, temperature and mechanical deformation. The results show that the electrolyte stability is related to the crosslinking reaction, which could be regulated by the amount of glutaraldehyde added in PVA. In addition, the supercapacitor prepared by 0.1 ml glutaraldehyde (GA) presents good reliability under the conditions of the increased temperature and mechanical deformation.