ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Solvothermal synthesis of nickel titanate nanosphere: crystal structure determination and high-rate supercapacitor performance

Debabrata Nandi, Harikrishnan Pulikkalparambil, Sabarish Radoor, Aswathy Jayakumar, Nuntawat Kiatisereekul, and Suchart Siengchin

Department of Materials and Production Engineering, The Sirindhorn International Thai–German Graduate School of Engineering (TGGS), King Mongkut’s University of Technology North Bangkok, Bangsue, Thailand

E-mail: nandi.debabrata87@gmail.com

Received: 20 May 2022  Accepted: 23 August 2022

Abstract:

The demand for high-rate supercapacitors with high power and energy density is increasing day by day. In this regard, the novel nickel titanate (NiTiO₃) nanosphere has been synthesized by the solvothermal method and used as a potential electrode material for supercapacitor. The crystal structure and bonding parameters in the unit cell of trigonal NiTiO₃ spinel have been explored from X-ray diffraction (XRD) analysis. The preferred oxidation states of Ni²⁺, Ti⁴⁺, and O²⁻ have been elucidated by X-ray photoelectron spectroscopy (XPS). Morphology study has confirmed the size/shape of the developed nanosphere. The electrode shows a high specific capacitance (885 F g⁻¹) and energy density (30.73 Wh kg⁻¹) without compromising power density (124.21 W kg⁻¹) at a current density of 0.5 A g⁻¹ in 1 M Na₂SO₄ and remains interestingly unchanged even change of current density from 0.5 to 2.5 A g⁻¹. After 10,000 cycles, it shows high-rate capability (~ 82%) and 95% Coulombic efficiency, inferring its promising stability. The relaxation time implies that the energy stored in the cell can release in 0.35 s, ensuring superior rate performance of NiTiO₃ nanosphere-based supercapacitor. The nanostructures as well as the synergistic effect of redox-rich Ni²⁺(d⁸) and Ti⁴⁺(d⁰) constituents pivotally govern the high-rate capacitive performance.

Graphical abstract

Keywords: Impedance; Nanosphere; Solvothermal; Supercapacitor; Unit cell

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02451-2

Chemical Papers 77 (1) 385–397 (2023)