Conversion of an Industrial Solid Waste to a Magnetic Material for Wireless Charging Devices of Electric Vehicles

The present study deals with the targeted material design and product development of a high-value polycrystalline Mn-Zn ferrite of the spinel structure, which is based on the conversion of the industrial solid waste of electrolytic manganese dioxide production plant. The final product can be used for the magnetic induction in wireless charging devices for electric vehicles. The experimental procedure was based on the proper handling of the solid waste, the development of the conventional ceramic process, and the appropriate adjustment of the chemical composition. The so developed Mn-Zn ferrite equivalent to the chemical formula (Mn_0.64Zn_0.36) Fe_1.57O₄ exhibited an initial permeability of μ = 48 at 10 kHz, 0.1 mT, 25 °C. The laboratory-developed protocol was scaled up to a semi-pilot plant for tile-shaped products, which were evaluated as magnetic shielding couplers via their incorporation into a prototype wireless charging unit, resulting in a 23% increase of the current intensity flowing through the electric vehicle’s battery. The integrated paradigm of circular economy towards sustainability is highlighted.