The sp Hybridization of Tin Single Atoms for Dendrite‐Free Sodium Metal Batteries

Restricting the growth of sodium (Na) dendrites at the atomic level is the premise to enable both the stability and safety of sodium metal batteries (SMBs). Here, the universal synthesis of the fourth main group element (Sn, Ge, Pb) as single metal atoms anchored on graphene (Sn, Ge, Pb SAs/G) with sp hybridization for dendrite-free sodium metal anode is reported. The in situ real-time observation of Na growth on Sn SAs/G uncoils a kinetically uniform planar deposition at the atomic level for substantially suppressing the dendrite growth. The symmetrical Sn SAs/G-Na battery exhibits high Coulombic efficiency of 99.8% for 200 cycles, long-term cyclability with 600 h at 4 mA cm