Realizing Highly Reversible Sodium Anodes by Amorphous VO _<i>x</i> -Decorated Sustainable Carbons

Sodium metal batteries (SMBs) are regarded as highly promising candidates for advanced energy storage technologies due to the intrinsically high theoretical capacity and low redox potential of sodium (Na) metal. Uncontrolled dendrite growth and poor interfacial stability remain major obstacles to the practical utilization of Na metal anodes. Herein, we report a sustainable strategy to fabricate a pollen-derived carbon decorated with amorphous vanadium oxide (A-VO_<i>x</i>@PC) nanoclusters via a one-step pyrolysis process, which is used as the substrate layer for the Na metal anode. The abundant chemical interactions between vanadium oxides and heteroatoms in PC promote the generation of amorphous VO_<i>x</i>. Experimental results and theoretical simulations reveal that the amorphous VO_<i>x</i> nanoclusters not only decrease the Na⁺ desolvation energy and interfacial diffusion barrier but also provide abundant and stable nucleation sites that promote homogeneous Na deposition. Consequently, the Na metal anode modified by A-VO_<i>x</i>@PC exhibits a low nucleation overpotential, uniform deposition, and exceptional cycling stability, delivering an average Coulombic efficiency of 99.79% over 750 cycles and a lifespan exceeding 1000 h in half cells. Moreover, full cells paired with a Na₃V₂(PO₄)₃ cathode demonstrate 90.4% capacity retention after 750 cycles at 1C, showing a good potential of A-VO_<i>x</i>@PC as a promising modifier for Na metal anodes in high-performance SMBs.