Comparison of the free-standing flexible electrodes fabricated with metallic 1T or semiconducting 2H MoS2 nanosheets and high conductivity PEDOT:PSS

Abstract

The improvement and promotion of the active materials in supercapacitors (SCs) have been gotten a lot of attention with the emergency awareness of environment protection and energy crisis. Herein, a free-standing flexible film was developed as the active electrodes of SCs, fabricated by mixing 1T or 2H MoS2 nanosheets with high electric conductivity poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) via vacuum filtration and H2SO4 post-treatment. The 2H MoS2–based hybrid electrodes with post-treatment and 10% mass ratio for 2H MoS2 to PEDOT:PSS exhibited highest specific capacitance of 89Fg−1 @ 0.1 A g−1. Through the comparison between 1T MoS2 and 2H MoS2-based hybrid electrodes, 2H MoS2–based hybrid electrodes presented higher capacitance properties than 1T MoS2–based hybrid electrodes at the mass ratio range of 5% to 20%, while the capacitance performance of 1T MoS2–based hybrid electrodes was higher at range of 30% to 40%. It was assumed that the conductivity and capacitance performance of hybrid films were enhanced with organic polar solution (N,N-dimethylformamide) and H2SO4 post-treatment under the mass ratio range of 5% to 20%. Also, the high intrinsic capacitance of 2H MoS2 nanosheets was not achieved due to the poor electric conductivity for the mass ratio range of 30% to 40%. Therefore, it was an effective strategy to fabricate free-standing flexible hybrid electrodes with stable 2H MoS2 nanosheets and high conductivity materials for flexible energy storage and conversion.