Facile fabrication of all-solid-state flexible interdigitated MnO2 supercapacitor via in-situ catalytic solution route

With the rapid development of wearable and portable electronics, the demand for all-solid-state flexible energy storage devices with high performance, long-term cycling stability and bending stability has been aroused. Physical and chemical method for preparing thin-film materials has enabled planar flexible supercapacitors (SCs) to be fabricated for a variety of applications. In this work, we report on the facile fabrication of an all-solid-state flexible interdigitated supercapacitor with a convenient and efficient two-step method. 3-D nanostructured α-MnO2 has been prepared on the surface of interdigitated Pt metal pattern on polyethylene terephthalate (PET) substrate as high-performance electrode material via in-situ catalytic solution route without any assistance of template or surfactant. The SCs are fabricated with PVA/H3PO4 as solid-state electrolyte, which exhibited good electrochemical performance with areal capacitance as much as 20 mF cm−2 at a scan rate of 10 mV s−1, relatively high energy density (3.6 × 10−7 Wh cm−2-1.9 × 10−6 Wh cm−2) and power density (9 × 10−5 W cm−2-1.6 × 10−4 W cm−2), and excellent long-term cycling stability with capacitance retention of 82.2% (10,000 times charge and discharge), and bending stability with capacitance retention of 89.6%.