Simple SILAR-synthesized Ni²⁺-doped polyaniline film for supercapacitor application

It has been recognized that conducting polymers could play a vital role as electrode material in supercapacitor application due to their high conductivity, fast charging, and discharging performance and ease of handling. Here, we prepared Ni²⁺-doped polyaniline (Ni-PANI) and polyaniline (PANI) films via oxidative chemical polymerization and studied their charge storage properties. A simple, inexpensive Successive Ionic Layer Adsorption and Reaction (SILAR) method was opted to grow composite material films on stainless steel conductor. The morphology and structural behaviour of prepared film electrodes were studied by FT-IR, XRD, and FESEM characterization techniques. The electrochemical properties of Ni-PANI and PANI were carried out in 1 M H₂SO₄ electrolyte using three-electrode system. Bare PANI showed the maximum specific capacitance of 667.5 F g⁻¹ at current density of 5 mA cm⁻². However, the doping of Ni²⁺ in PANI enhanced the specific capacitance to 1060 F g⁻¹. In addition, this SILAR-synthesized binder-free Ni-PANI film showed good stability of 84% for 3000 CV cycles.