Influência de tratamentos superficiais em heteroestruturas TiNb2O7/Ni81Fe19

Abstract

Over the past decades, the global shift towards clean energy sources has intensified, driven by the urgent need to reduce carbon emissions and our reliance on fossil fuels. Within this context, energy storage systems are crucial, and lithium-ion batteries (LIBs) are emerging as one of the most promising technologies. However, conventional graphite anodes, widely used in these batteries, face significant limitations, which has driven the search for alternative materials. Titanium niobate (TNO) emerges as a viable candidate, as it can be synthesized relatively simply through a solid-state reaction between TiO₂ and Nb₂O₅. Despite its advantages, TNO presents challenges that need to be overcome. A promising approach is the combination of this material with nickel-iron (NiFe) alloys, along with techniques such as tape casting for controlling electrode morphology and porosity. Additionally, surface treatments can be applied to reduce roughness and uniformize the surface, facilitating the deposition of ferromagnetic materials via magnetron sputtering and improving adhesion between the substrate and thin film. This study investigates a TNO/NiFe heterostructure, produced by combining tape casting and magnetron sputtering, with the objective of evaluating its potential for LIB applications. The developed materials were characterized regarding their structural, morphological, electrical, dielectric, and magnetic properties. The results of these samples indicated a reduction in surface roughness by approximately 80%, leading to a decrease of about 90% in electrical resistance, which was reduced from 4.38 kΩ to 0.27 kΩ after polishing. The magnetic properties were also influenced, with a notable decrease in saturation and coercive fields, which was reduced from 13 Oe to 4 Oe as polishing was intensified. The results demonstrate the success of polishing in improving the electrical and magnetic properties of the heterostructure. The combination of tape casting with polishing proved to be an effective approach for producing TNO substrates with potential applications in batteries. The integration of LIB components with ferromagnetic layers aligns with recent research on the use of magnetic fields in ionic dynamics, driving the development of advanced battery technologies.