One‐Pot Synthesis of a Nitrogen‐ and Iodine‐Doped Graphene Composite for Energy Storage Applications

Abstract With the growth of power generation, portable electronic devices are gaining more attention toward energy storage devices, preferably supercapacitors. In this, the surface of graphene was functionalized with conductive polymer by in situ polymerization of pyrrole (PPy) and doping of iodine via hydrothermal method. Doping iodine (potassium triiodide) and nitrogen (polypyrrole) from their respective precursors made GNI composition more suitable for energy storage applications. The synthesized GNI composite showed the maximum specific capacitance of 200 F g −1 at 1.0 Ag −1 with an efficient specific energy of 22.5 Wh kg −1 and specific power of 1800 W kg −1 in a symmetrically arranged two‐electrode Swagelok type cell. The durability of the synthesized composite was analyzed by cyclic stability at current density 10 Ag −1 , retaining up to 85% of its initial capacitance after 10,000 repetitive charge‐discharge cycles. The in situ polymerization of pyrrole with the insertion of iodine makes graphene composition more conductive than control graphene, showing a specific capacitance of 111 F g −1 at 1.0 Ag −1 . The one‐pot synthetic approach is a simple, easy, and efficient route toward supercapacitor applications. This approach will provide an easy way to introduce N and I to graphene compositions for various applications, including energy storage materials.