3D multi-walled carbon nanotubes decorated Nb2O5 cathode materials for Al-air batteries

In this study, we present the novel synthesis and characterization of 3D multi-walled carbon nanotubes (MWCNTs) decorated with niobium(V) oxide (Nb2O5) for use as cathode materials in aluminum-air (Al-air) batteries. This innovative approach addresses the challenge of enhancing oxygen reduction reaction (ORR) kinetics, which is essential for improving Al-air batteries’ energy efficiency and commercialization potential. The synthesis process involved chemical vapor deposition of MWCNTs, functionalization with nitric acid, and decoration with Nb2O5 using the citrate sol-gel method. Characterization techniques such as X-ray diffraction (XRD), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to analyze structural properties and confirm the successful Nb2O5 decoration. The MWCNTs@Nb2O5 sample exhibited a significant increase in specific surface area and enhanced porosity, critical for effective ORR catalysis. Electrochemical evaluations demonstrated improved ORR activity with Nb2O5 decoration, evidenced by higher peak current and lower overpotential than undecorated MWCNTs and conventional electrodes. Al-air batteries MWCNTs@Nb2O5 cathodes showed superior performance, with higher open circuit voltage and stable discharge plateau, leading to a 1.35-fold increase in specific capacity. This research highlights the potential of MWCNTs@Nb2O5 as efficient cathode materials for Al-air batteries, paving the way for more efficient and commercially viable metal-air battery technologies.