Advanced porosity engineering of carbon nanofiber electrodes via polyurethane additives and laser carbonization for high-performance flexible microsupercapacitors

Abstract Carbon nanofibers electrodes demonstrate a very high potential for constructing flexible microsupercapacitors for integration with wearable electronics based on their high electrochemical performance and excellent mechanical characteristics. A continuation of our previous work, a readily available technique for the porosity engineering of carbon nanofibers electrodes for flexible microsupercapacitors using Polyurethane additives and CO 2 laser carbonization is introduced here. In this work, the structural properties, surface morphology, and electrochemical performance of the laser-carbonized electrodes constructed from different polyacrylonitrile to polyurethane ratios are also explored and discussed in detail. As a result of optimizing the polyurethane ratio, the microsupercapacitor based on 10% PU concentration recorded an electrode areal specific capacitance of 45.3 mF/cm 2 , in addition to high energy and power densities of 1.4 μWh/cm 2 and 243 μW/cm 2 , respectively, which are much enhanced compared to the parameters achieved by the plain device. The enhancements in the electrocapacitive performance were attributed to the construction of a 3D open porous electrode structure and good surface porosity without destroying the main fibrous morphology nor the electric conductivity pathways for the laser-carbonized nanofiber electrodes. These enhancements were in conjunction with ideal capacitance retention of 96.8% after 10,000 charging–discharging cycles and remarkably stable performance under mechanical deformations.