Spherical V2O5/C Cathode Materials Prepared by Spray Drying for High-Power Thermal Batteries

Commercial V2O5 powders typically exhibit a lamellar morphology with limited structural stability and sluggish electron/ion transport, which restricts their discharge performance in thermal batteries. This work aims to enhance the discharge performance of V2O5 cathodes by constructing a robust spherical architecture via a scalable spray drying strategy combined with carbon modification. The as-prepared V2O5/C cathode delivers a high initial discharge voltage of 2.45 V, a specific capacity of 261.06 mAh g−1, and an energy density of 591.05 Wh kg−1 at 0.1 A cm−2 and 500 °C (cut-off voltage of 1.9 V), outperforming those of commercial V2O5 cathodes. Pulse discharge tests and resistance evolution analyses further demonstrate enhanced voltage stability and reduced interfacial resistance. These improvements originate from the synergistic effect of the spherical architecture and conductive carbon network, which facilitates continuous electron/ion transport and reinforces structural integrity under high-temperature discharge conditions. This work provides a scalable design strategy for high-tap-density spherical V2O5 cathodes and offers insight into the coupling among morphology, conductivity, and stability in cathode materials for thermal battery.