Fabrication of a high-performance symmetrical supercapacitor based on electrochemically interconnected cu: Nio@rgo: Pani/nf electrodes

Abstract

A three-step electrodeposition synthesis was carried out to prepare a nanocomposite electrode of copper-doped nickel oxide and reduced graphene oxide-doped polyaniline with synergistic effects. Nickel foam was utilized as a current collector. XRD, FTIR and XPS studies confirm the molecular bond formation and molecular phase of the produced materials. According to the EDS results, the rGO:PANI/NF electrode contains 0.29 % nitrogen (N), 17.39 % carbon (C), and 9.81 % oxygen (O), while the Cu:NiO@rGO:PANI/NF electrode contains 8.24 % copper (Cu), 9.22 % carbon (C), 7.21 % oxygen (O), and 0.72 % nitrogen (N). The electrochemical performance of rGO:PANI/NF and Cu:NiO@rGO:PANI/NF electrodes were tested in a three-electrode cell with 3 M KOH aqueous electrolyte. High specific capacitances of 644.5 and 807.1 Fg(-1) are achieved with the rGO:PANI/NF and Cu:NiO@rGO:PANI/NF electrodes at a current density of 20 Ag-1, respectively. The Cu:NiO@rGOPANI/NF also has a lower charge transfer resistance (R-CT = 0.9 Omega) than the rGO:PANI/NF electrode (R-CT = 3.8 Omega). This means NiO plays a crucial role in facilitating the transportation of charges between rGO:PANI. NiO acts as a "superhighway" that enables efficient and speedy charge transport. The expanded BET surface area of Cu:NiO@rGO:PANI/NF can be attributed to a well-interconnected network of PANI chains with NiO. In order to demonstrate a further application, an all-solid-state symmetrical supercapacitor (SSC) was then fabricated using the Cu:NiO@rGO:PANI/NF electrodes. The operating potential range is between 0 and 1.5 V. The device has a good capacitance of 81.9 Fg(-1) at 4.5 Ag-1, and a capacitance retention of 97.6 % at a specific current of 10 Ag-1 after 10,000 cycles. The symmetrical device has a maximum energy density of 25.6 Wh kg(-1) at a high power density of 1297.6 W kg(-1) at 4.5 A g(-1). In light of these results, the nanocomposite-based solid-state supercapacitor is considered to be a promising device for the development of high-performance symmetric supercapacitors.