Lanthanum ion (La3+) substituted CoFe2O4 anode material for lithium ion battery applications

Abstract

Mesoporous CoFe₂O₄ and lanthanum ion (La³⁺) substituted CoFe₂O₄ nanoparticles of composition CoLa_0.06Fe_1.94O₄ were prepared by the citric acid and urea assisted combustion process and the citric acid, urea, and glycerol assisted foam combustion process, respectively. The effect of lanthanum ion substitution on the crystallite size, the lattice parameter, the particle morphology and electrical properties of pristine CoFe₂O₄ is studied using powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and impedance spectroscopy. For electrochemical studies, half cells are fabricated in CR 2032 coin cells using mesoporous CoFe₂O₄ and CoLa_0.06Fe_1.94O₄ as anode materials. The charge/discharge performances of half cells are studied using cyclic voltammetry and charge/discharge cycling. The rare earth ion substitution improved the structural stability of pristine CoFe₂O₄ and enhanced the oxidation reaction which maintained the number of lithium ions involved in the oxidation and reduction reactions. It also improved the battery performance, for instance, the specific capacity of La³⁺-ion doped CoFe₂O₄ is 188% compared to the pristine CoFe₂O₄ anode even after 50 cycles.