Hydrothermal synthesis and electrochemical performances of 1.7 V NiMoO₄⋅xH₂O||FeMoO₄ aqueous hybrid supercapacitor

Baskar Senthilkumar; Ramakrishnan Kalai Selvan

doi:10.1016/j.jcis.2014.04.010

Hydrothermal synthesis and electrochemical performances of 1.7 V NiMoO₄⋅xH₂O||FeMoO₄ aqueous hybrid supercapacitor

J Colloid Interface Sci. 2014 Jul 15:426:280-6. doi: 10.1016/j.jcis.2014.04.010. Epub 2014 Apr 13.

Authors

Baskar Senthilkumar¹, Ramakrishnan Kalai Selvan²

Affiliations

¹ Solid State Ionics and Energy Devices Laboratory, Department of Physics, Bharathiar University, Coimbatore 641 046, India.
² Solid State Ionics and Energy Devices Laboratory, Department of Physics, Bharathiar University, Coimbatore 641 046, India. Electronic address: selvankram@buc.edu.in.

PMID: 24863794
DOI: 10.1016/j.jcis.2014.04.010

Abstract

One-dimensional (1D) NiMoO4⋅xH2O nanorods and β-FeMoO4 microrods are successfully synthesized by simple hydrothermal method without using any organic solvents. X-ray diffraction (XRD) patterns reveal the single phase formation of nickel molybdate (NiMoO4⋅xH2O) and pure monoclinic phase of β-FeMoO4. The growth of one dimensional morphology of both the molybdates are identified from scanning and transmission electron microscopes (SEM and TEM). The cyclic voltammogram envisage the pseudocapacitance behavior of NiMoO4⋅xH2O and β-FeMoO4 through the reversible redox reactions of Ni(3+)/Ni(2+) and Fe(3+)/Fe(2+) ions. An asymmetric supercapacitor is fabricated using NiMoO4⋅xH2O nanorods and β-FeMoO4 as a positive and negative electrode, respectively. The β-FeMoO4||NiMoO4⋅xH2O asymmetric supercapacitor delivers a capacitance of 81 F g(-1) at a current density of 1 mA cm(-2). The cell exhibits a high energy density of 29 W h kg(-1) and good cycling stability even after 1000 cycles.

Keywords: Asymmetric capacitor; Energy density; Iron molybdate; Nickel molybdate; Pseudocapacitance.