60-Second NIR Regeneration of H-Phase Nb2O5 from Production Scrap: A Sustainable, Scalable Route to High-Capacity Anode Recovery

The escalating demand for high-performance lithium-ion batteries has intensified the need for sustainable electrode material recovery strategies that minimise energy consumption and processing time. Here, we report a rapid, energy-efficient nearinfrared (NIR) irradiation approach for the regeneration of niobium pentoxide (Nb2O5) from production scrap comprising a slurry of Nb2O5 active material, polyvinylidene fluoride (PVDF) binder and carbon black conductive additive. NIR irradiation at 100% intensity achieves simultaneous and complete decomposition of both binder and carbon black within 60 seconds, as visually confirmed by a colour transition from dark grey to white, a result that conventional furnace sintering achieves only after 8 hours at 600 °C, representing a reduction of more than two orders of magnitude in processing time. Differential scanning calorimetry (DSC) confirms the disappearance of the crystallisation and melting transitions associated with the binder phase following both treatments. X-ray diffraction (XRD) and scanning electron microscopy (SEM) demonstrate that NIR irradiation preserves the crystal structure and morphology of the regenerated Nb2O5 to a degree comparable with conventional thermal treatment. Raman spectroscopy confirms the complete elimination of the carbon black D and G bands in the treated materials, validating conductive additive removal. Galvanostatic charge-discharge (GCD) measurements show that the regenerated Nb2O5 anode delivers a specific capacity of 232.58 mA h g−1, comparable with the furnace-treated material and consistent with the high-capacity H-Nb2O5 polymorph. Cyclic voltammetry (CV) confirms redox peak positions consistent with H-phase Nb2O5, while kinetic analysis reveals a hybrid charge-storage mechanism dominated by solid-state diffusion with a minor capacitive contribution, underpinning the high capacity and electrochemical stability observed. These results establish NIR irradiation as a time- and energy-efficient platform for closed-loop Nb2O5 electrode regeneration, with strong prospects for industrial-scale battery recycling.