Highly Sodiophilic Heterostructures Toward Dendrite‐Free Sodium Metal Batteries

Abstract The utilization of Al current collector for the sodium deposition is considered ideal for achieving a low‐cost, high‐energy‐density sodium metal battery. However, the poor affinity between sodium and Al leads to uneven sodium plating/stripping, which poses a significant challenge in the pursuit of a stable sodium metal anode. Herein, a heterostructure (V/VO x )‐modified Al current collector is proposed, which effectively enables a highly reversible Na plating/stripping process, and inhibits Na dendrites growth. Experimental results and theoretical calculations demonstrate that the V/VO x @Al not only exhibits strong sodiophilicity, but also ensures a uniform current density distribution. Thanks to these merits, the assembled cells demonstrate excellent performances with low nucleation overpotential (11 mV at 1 mA cm −2 ), and long cycle life (2750 h) with minimal voltage polarization (13 mV at 1 mA cm −2 ). More impressively, the assembled full cell displays remarkable stability, sustaining 1400 cycles at 10 C. This work provides valuable insights for the development of more stable sodium metal batteries.