Modulating the electrochemical capacitance of NiFe2O4 by an external magnetic field for energy storage application

Due to their differentiated structure and properties, nanoporous metals gain great attention in several areas, such as catalysis and energy storage. The effects of magnetic fields on electrochemical processes affect the theoretical and practical performance of the capacitors. This work describes the effect of a external magnetic field on the electrochemical performance of nickel ferrite nanoparticles prepared by the proteic sol-gel method. Here the electrochemical capacitance and the cyclability of the electrodes modified by the NiFe2O4 nanoparticles are compared without the intervention of any magnetic field and with the presence of a magnetic field of 200 mT flow density. Our experimental data showed that the studied material under an external magnetic field has a much better electrochemical performance when compared with the one without the application of a magnetic field. A magnetic field can improve the capacitance, reduce the charge transfer resistance and enhance the discharge performance. The improvement in the capacitance of the magnetized electrode increases 29.3 % in the current density of 1 A g(-1), and the cyclability increases around 69.1 % when compared to the tested electrode without the magnetic field. Therefore, our results show an alternative way to improve the electrochemical performance of energy storage materials.