Electrochemical Characterization of Lithium Ferrite Electrodes through Cyclic Voltammetry and Raman Spectra

Abstract

Lithium ferrite, a mixed spinel with the formula, Fe[Li_0.5Fe_1.5]O₄ or LiFe₅O₈, has been synthesized and characterized in both its ordered (α) and disordered (β) phases. In an effort to scope the electrochemical activity lithium ferrite in lithium hydroxide solutions, the powders produced were compressed into pellets and tested with cyclic voltammetry and the surface of the electrodes were analyzed with laser Raman spectroscopy. Results of the initial electrochemical testing showed good correlation with Nernstian behavior and exhibited quasi-reversible behaviour. The redox mechanism involves the breakdown of lithium ferrite into hematite, a hybrid lithiated-hematite oxide and lithium ions under the alkaline conditions tested. By comparing the equilibrium potential of the redox process with proposed reaction schemes and examining the reaction products using the laser Raman microprobe, the proposed redox mechanism could be verified.