Sp³‐Like Hybridisation Induction Regular Charge Accumulation Driving C‐Na Lattice Matching Toward Dendrite‐Free Sodium Deposition

Abstract Carbon defects featuring unsaturated coordination electrons and charge polarization are widely investigated as anodes for alkali metal batteries, yet curved lattice carbon remains undefined. This study explores the sodium (Na) deposition mechanism on curved‐lattice carbon surfaces and proposes a novel approach for achieving smooth sodium deposition based on density functional theory calculations and binder‐free helical carbon nanofibers (HCNFs) host. Curved carbon lattice induces sp^x (2<x<3) hybridization, causing regular charge accumulation and thereby promoting C‐Na lattice matching. Specifically, the curvature‐dependent sodalophilic sites induce either a parallel distribution of sodium (Na–Na = 4.92 Å) or a perpendicular distribution (Na–Na = 3.45 Å) with easily dissolved crystalline embryos. Simultaneously, the ordered helical structure of HCNFs effectively generates an array of interstitial pores (<100 nm), which enhances capillary effects and thereby strengthens the wettability of the electrolyte (contact angle of 20 °). In situ transmission electron microscopy reveals that the HCNFs excellent outstanding smooth dendritic behavior. Consequently, the HCNFs anode delivers a low nucleation overpotential of 8 mV and remarkable stability over 4000 h. The full‐cells display an impressive capacity retention of 90% after 140 cycles. This novel mechanism for dendrite‐free deposition offers a new strategy for high stability sodium metal anode.