Preparation Of Carbon-based Elastic Conductors And Their Applications In Stretchable Devices

In recent years,stretchable devices have been applied to all aspects of our life,which has attracted lots of attention.As the basis of stretchable devices,elastic conductive nanocomposites are the focus of present research.Electronic devices based on elastic nanocomposites can perform a series of operations such as stretching and bending,making it possible to wear,stretch,and implant.In this study,CB(carbon black)-TPU(thermoplastic polyurethane)and Graphene-TPU conductive nanocomposites were prepared by uniformly dispersing conductive fillers in an elastomer matrix using a solution mixing-blade coating process.According to the percolation theory,the percolation thresholds of CB-TPU and Graphene-TPU composites are 3.5 vol%and 2.2 vol%,respectively,and the conductivity increases linearly with the 1g(φ-φ0).As the volume fraction increases,the R/R0-strain corresponding of the two composite show different laws,both the exponential growth region of the R/R0-strain corresponding curves follow:R/R0∝10nε.The Young’s modulus of the composite decreases with the increase of the volume fraction,CB is easier increases the tensile strength of the composite,and graphene is easier to increase the Young’s modulus.According to the synergistic effect between conductive fillers,Graphene/CB-TPU conductive nanocomposite materials were prepared by mixing graphene and CB in different proportions.The nanocomposites have a lower percolation threshold,and the electrical conductivity and tensile properties are improved at the same time.Among them,the Graphene/CB3:7-TPU-15.1 vol%composite afford an initial conductivity of 12.5 S cm-1 with an elongation of 140%,the whole performance is significantly better than those of composites with only one filler(Graphene or CB)at the same volume fraction.In addition,the composites with binary fillers have stable electromechanical properties,and are durable when being stretched for 1000 cycles.The performance of Graphene/CB3:7-TPU-15.lvol%nanocomposites prepared by 3D-printing are similar to those of composites prepared by blade coating.The stretchable Zn-MnO2 battery with a nanocomposite current collector has an initial specific discharge capacity of 324.7 mAh g-1 and a coulomb efficiency of 95%.This material was also used to prepare a stretchable MnO2 supercapacitor with an area specific capacitance of 72.6 mF cm-2.And it can be used in strain sensors by adjusting the ratio of graphene and CB and the total carbon content.Proving that Graphene/CB-TPU composite has wide application prospects in the field of stretchable electronic devices.