Flexible, sandwich-like Ag-nanowire/PEDOT:PSS-nanopillar/MnO2 high performance supercapacitors

We demonstrate the design and fabrication of a Ag/PEDOT:PSS/MnO2 layer by layer structure for high performance flexible supercapacitors (SCs). This is a unique design combining Ag-nanowires and PEDOT:PSS-nanopillars as current collectors in SCs. In this sandwich-like structure, electrons can be easily transferred through a networked structure of Ag-nanowires to PEDOT:PSS-nanopillars and finally to the MnO2 layer and vice versa. This scheme provides excellent specific capacitances of 862 F g(-1) (based on MnO2) at a current density of 2.5 A g(-1) and robust long-term cycling stability. Moreover, SCs fabricated based on this structure exhibit exceptional flexibility and bendability (less than 2% loss in specific capacitance even after 100 bends) and high energy and power densities. All wet processing methods of fabrication along with superior performance make these SCs very attractive for the next generation flexible energy storage systems.