Room Temperature Fabrication of Binder-Free Na₃V₂(PO₄)₃/C High-Loading Electrode Films via the Powder Aerosol Deposition Method

The powder aerosol deposition (PAD or aerosol deposition method ADM) and tape casting were used to manufacture Na3V2(PO4)3/C (NVP/C) electrodes from the same synthesized powder batch. We demonstrate that Na-based, binder-free and solvent-free thick PAD electrodes can be directly deposited onto aluminum current collectors. Tape-cast electrodes were fabricated on aluminum foil to serve as a reference for electrochemical benchmarking. Galvanostatic cycling was performed at a C-rate of C/10 between 1.5–4.5 and 2–4 V versus Na+/Na using a liquid electrolyte in coin cells. PAD electrodes with varying cathode active material (CAM) loadings were produced to evaluate the effect of loading and posttreatment on the electrochemical performance. While tape-cast electrodes show consistent capacities (∼90 mAh g−1 at C/10), PAD electrodes delivered significantly lower specific capacities depending on CAM loading and posttreatment. By correlating delivered charge with active mass and thickness, we show that the charge extracted from PAD-NVP/C cathode exhibit a plateau at ∼0.15–0.18 mAh, independent of CAM loading. This indicates that only a thin fraction of surface region participates in de/-intercalation. These findings reveal the utilization limits in thick PAD cathodes and provide insight toward enabling their future industrialization.