Antimony Telluride as Bifunctional Host Material for Dendrite-Free Sodium Metal Batteries

The development of the sodium metal anode is hampered by uncontrolled Na dendrite growth and unstable solid electrolyte interface (SEI). Herein, Sb₂Te₃ nanosheets are anchored into the fibers of carbon cloth (CC) to construct Sb₂Te₃@CC material as Na metal host for sodium metal batteries (SMBs). The alloying product of Na₃Sb with strong sodiophilicity serves as a nucleation seed to induce homogeneous Na deposition and boost the formation of a dendrite-free Na metal anode. Meanwhile, the conversion product of Na₂Te covers the surface of Na metal to form a robust SEI film. Low current density, uniform Na ionic flux, and suppressed volume expansion can be guaranteed by three-dimensional carbon fibers. Therefore, a Na@Sb₂Te₃@CC electrode contributes ultrastable cyclic performance for over 1600 h with a low overpotential of 30.5 mV. The assembled Na metal full batteries deliver a high initial energy density of 307.3 Wh kg^-1 and superior cycling stability with an ultralong lifespan of over 2000 cycles.