Beyond Polypyrrole: Pencil-Drawn Paper-Based Supercapacitors with High Energy Density

The construction of conductive graphite channels on paper using the pencil drawing method for supercapacitors and sensors has been reported, but its performance needs to be improved to meet practical applications. In this, we develop green and efficient method to prepare high-performance supercapacitor electrodes. After pencil drawing, the polypyrrole graphite active material (PPy-G) is prepared via interfacial polymerization. The graphite layer not only provides an efficient electron transport path but also greatly increases the electrical capacity of electrodes with a good combination of PPy. The prepared electrodes exhibit an excellent area specific capacitance (1654 mF cm−2) and good cycling stability (at 95.3% after 10,000 cycles). Furthermore, the symmetric supercapacitor is prepared using the dual electrodes exhibit a good energy density of 159.6 μWh cm−2 at a power density of 0.8 mW cm−2. The kinetic processes for the electrodes are also further investigated.