Mesoporous perovskite of interlocked nickel titanate nanoparticles for efficient electrochemical supercapacitor electrode

Abstract

We have synthesized mesoporous nickel titanate (NTO) rods encompassing interlocked nanoparticles with clearly visible textural boundaries via the sol-gel route, as an excellent working electrode for the supercapacitor. The mesoporous NTO rods assembled in the hexagonal shape of average diameter ∼ < 1 μm and ∼3–6.4 μm long, are composed of nanoparticles of diameter ∼46 nm. The well crystalline NTO rods of the hexagonal phase to the space group of R–3H possess average (mean) pore size distribution of 17.48 nm throughout the rod body. The stoichiometric mesoporous NTO rods with increased textural boundaries played a significant role in the larger diffusion of ions, and delivered the specific capacitance (Cs) of 542.26 F/g, the energy density of 8.06 Wh/kg and a power density of 4320 W/kg in an aqueous KOH electrolyte, is significantly better than Ni, Mn, Fe, Cr, and Ti-based perovskites or their mixed-phase accompanied by metal oxides as impurities. Moreover, the diffusion-controlled easy/faster and enhanced access to the OH− ions (20.4 μs) deep inside the rod body, delivered long life cycle, high stability up to 2100 cycles, and excellent retention of 91%. Overall, mesoporous NTO rods hold potentials as an electrode material for long cycle lifetime supercapacitor and holds possibilities for further improvement after forming the nano-hetero-architecture or hybrid structures with other prominent materials such as NiO, and Mn2O3, etc. © 2020 Elsevier B.V.