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.