Double in situ fabrication of PPy@MnMoO4/cellulose fibers flexible electrodes with high electrochemical performance for supercapacitor applications

Abstract

Cellulose fibers (CFs) are used as a substrate to fabricate the flexible supercapacitor electrodes of PPy@MnMoO4/CFs via double in situ deposition method. The fabricated MnMoO4/CFs (MC), PPy@CFs (PMC0) and PPy@MnMoO4/CFs (PMC6) are characterized by SEM, XRD, FTIR and XPS, and the electrochemical tests are implemented to reveal the structure–property relationship of paper samples. The results show that the electrochemical performance of PPy@MnMoO4/CFs have positive correlation with the concentrations of the precursor solutions of generated MnMoO4. The PMC6 fabricated at equal molar concentration (0.06 mol L−1) of Mn(CH3COO)2 and Na2MoO4 has the best electrochemical performance, and the specific capacitance achieves 440.1 F g−1 at a current density of 0.2 A g−1, retaining about 83.0% after 1000 cycles at a current density of 2 A g−1. However, the specific capacitance of PMC0 reaches merely 236.8 F g−1 and maintains about 74.0% under the same conditions. The PMC6 electrode has excellent electrochemical performance when compared with PMC0, which is due to the interaction between PPy molecular chains and MnMoO4 submicron rods. MnMoO4 submicron rods not only act as the PPy deposition template to modify the morphology of PMC6 composite, but also create more paths for the transfer of electrolyte ions, to ensure a higher reaction rate and a specific capacitance.