Facile fabrication of low-cost and scalable graphite tape as novel current collectors for flexible supercapacitors

Abstract

Flexible supercapacitors are regarded as a good candidate for powering flexible and wearable electronics. Currently, flexible current collectors for supercapacitors are still limited. Carbon-based materials with high conductivity and good flexibility are excellent current collectors for supercapacitors. However, the synthesis process for carbon-based current collectors is very tedious and time-consuming, leading to high synthesis cost. Here, graphite tape composite based current collectors with high electric conductivity and flexibility have been developed by simply peeling off a thin graphite layer with a tape from a low-cost graphite sheet. The graphite tape can be easily scaled up, has an electric conductivity of 1395 S/m, and maintains stable conductivity during different bending states. The optimized MnO2@graphite tape electrode shows a maximum specific capacitance of 577.5 mF/cm2 at 0.5 mA/cm2. The supercapacitor based on the optimized electrode delivers a high specific capacitance of 189.3 mF/cm2 and excellent flexibility during different bending states and 2000 bending cycles. The high performance of electrodes and supercapacitors is related to the excellent conductivity and good mechanical flexibility of the graphite tape. This work opens up a facile fabrication method for low-cost, scalable, and high-performance carbon-based current collectors for flexible supercapacitors.