Supercapacitors based on freeze dried MnO2 embedded PEDOT: PSS hybrid sponges

• Cost effective freeze dried electrodes using PEDOT: PSS/MnO2 is prepared.
• Mass capacitance is found to be 1068 F g−1.
• Electrodes showed superior stability even at the end of 2000 cycles.

The present study investigates in detail the synthesis and characterization of PEDOT: PSS/MnO2 hybrid sponge electrodes for supercapacitor/battery applications. These hybrid sponges were prepared using freeze drying technique and showed hierarchical pores ranging from micron to nanometric size. Scanning electron microscopy-energy dispersive X-ray showed uniform dispersion of MnO2 along the PEDOT: PSS matrix. Thermo gravimetric-differential thermal analysis showed higher thermal stability for these hybrid constructs compared to PEDOT: PSS sponges. From the electrochemical studies, an intrinsic correlation between overall specific capacitance, morphology and weight percentage of MnO2 in the PEDOT: PSS matrix has been defined and explained in KOH electrolyte system. High cyclic stability was observed at the end of 2000 cycles for these hybrid sponges with less than 5 % capacitance fading. These sponges exhibit mass specific capacitance values as high as 10688 F g−1 which was found to be 35% higher compare to PEDOT: PSS sponges as obtained from Weibull statistics. The application of these electrodes was explored in a fully functional asymmetric coin cell unit where an energy and power density of 200 mWh kg−1 and 6.4 kW kg−1, was obtained, respectively.

Freeze dried MnO2/PEDOT: PSS sponges.Figure optionsDownload as PowerPoint slide