Study On The Preparation And Performance Of Thin-Film All-solid-state Stretchable Supercapacitors Based On Carbon Nanotubes Array

Currently,it remains a great challenge to achieve all-solid-state supercapacitors with both high electrochemical performance and excellent stretchability because of the deficiency of stretchable electrodes and solid-state electrolytes.Transition metal sulfides and conducting polymers are widely used in supercapacitors because of their excellent electrochemical properties.Carbon nanotubes have attracted wide attention for their good mechanical stability.Here,we developed all-solid-state supercapacitors by using aligned carbon nanotube/molybdenum disulfide?MoS₂?and carbon nanotube/Ag-doped poly?3,4-ethylenedioxythiophene?-poly?styrenesulfonate??PEOT:PSS?composites as electrodes and polyvinyl alcohol/phosphoric acid?PVA/H₃PO₄?as electrolyte.The biaxial stretchable all-solid-state supercapacitors were prepared by vertical stacking method for the first time.This paper provided a simple and effective way for developing stretchable and biaxial stretchable supercapacitors.There are three major sections in this paper:Firstly,layered MoS₂ was prepared by hydrothermal synthesis method and carbon nanotubes array was obtained by chemical vapor deposition?CVD?method.Electrochemical performance of the supercapacitors,which assembled of carbon nanotubes?CNTs?with different amount of MoS₂,was characterized.The specific capacitance of the supercapacitors was as high as 8.17 mF/cm².The prepared supercapacitors exhibited superior stretchability.There was almost no change for electrochemical properties of the supercapacitors and the excellent mechanical stability could be observed when the samples were stretched to 160%.Subsequently,the PEDOT:PSS was modified by doping Ag.When the content of Ag in PEDOT:PSS was 1.0%,the CNTs loaded Ag doped PEDOT:PSS was12.4wt%.The obtained all-solid-state supercapacitors not only exhibited high specific capacitance of 64 mF/cm²?corresponding 85.3 F/g?,but also maintained 98%even under a tensile strain as high as 480%.The value represented the highest value for thin-film all-solid-state supercapacitors using the same electrolyte to date,to our best knowledge.The newly-developed thin-film supercapacitor maintained 90%of its original capacitance after 100 stretching cycles to tensile strain of 400%,indicating the excellent stretching stability.Finally,on the basis of uniaxial tension,a vertical stacking method was established to prepared biaxial stretchable supercapacitors.The electrochemical performance of the prepared supercapacitors were less affected by the stack effect,and the specific capacitance was only decreased 13%.The supercapacitors could maintain 92.9%of their original capacitance under a biaxial tensile strain as high as96%,indicating the excellent stretching stability.