Synthesis of calcium ferrite for energy storage applications

This work proposes the synthesis of calcium ferrite particles for application in electrical energy storage. The ferrites were prepared using calcium and iron nitrates as base materials, by a protein sol-gel method, using coconut water, an ”eco-friendly” and sustainable route. The powders obtained were pressed into disks and heat-treated at temperatures ranging from 400 ° to 1000 °C. For various heat treatment temperatures, the samples were subjected to structural, morphological, and electrical characterization. The desired crystalline phase (CaFe2O4) is present in the samples treated from 700 °C onwards. However, it is only in the samples heat-treated at 800 and 1000 °C that this crystalline phase is present without secondary phases. From the morphological analysis, CaFe2O4 grains with an average size of 0.3 µm (sample 800 °C) and 1.2 µm (sample 1000 °C) were obtained. Regarding the electrical measures, the most promising sample is the one treated at 1000 °C because it presents a dielectric constant value of 7,132 and dielectric losses of 1.79, at 300 K and 100 Hz.