Na Storage in Sb₂S₃@C Composite: A Synergistic Capacity Contribution Mechanism with Wider Temperature Adaptability

The practical applications of metallic anodes are limited due to dendritic growth, propagation in an infinite volume during the plating process, and parasitic interfacial reactions between sodium (Na) and the electrolyte. Herein, we developed Sb₂S₃ microrods as a template to regulate the nucleation of metallic Na. Additionally, the propagation of the deposited metal could be spatially regulated via a “nanoconfinement effect”, that is, within the conformal hard carbon (C) layer of nanothickness. Moreover, we carefully studied the seed effect of the in situ-formed Na-Sb and Na-S alloys within the hard C sheath during the Na plating process. The symmetrical cells of the Sb₂S₃@C composite anode achieved dendrite-free cycling at 1 mA cm^-2 for 1100 h at a high capacity loading of 1 mA h cm^-2 and considerably mitigated a nucleation overpotential of 20 mV. Pairing a NaVPO₄F (NVPF) cathode (4.6 mg cm^-2) with an in situ presodiation Sb₂S₃@C composite (2*Na excess) prototype delivered a high energy density and a high power density of 173.75 W h kg^-1 and 868.57 W kg^-1, respectively. Therefore, this study provides tremendous possibilities for employing the proposed hybrid storage mechanism in low-cost and practical applications of high-energy-density Na metal batteries.