Modulating Internal Coordination Configurations for High-Density Atomic Antimony toward Advanced Fast-Charging Sodium-Ion Batteries

Fast-charging ability of sodium-ion batteries (SIBs) is mainly determined by a highly effective redox reaction rate. However, traditional metal@carbon composites rarely achieve atom-level dispersion at high density, resulting in poor reaction rates. Herein, supported by the introduction of carbon vacancies, abundant CS/CO chemical bonds are successfully established in a carbon carrier. Then, plenty of Sb single atoms (Sb SA/PC) are first anchored with a high loading of 31.4 wt%, achieving a high yield of 210.56 g per batch. Benefiting from dense SbOC/SbSC interfacial chemical bonds, SbS2O coordination configurations are firmly confined in the interior of carbon. Surprisingly, the conductivity of Sb SA/PC-2 is approximately 2.2 x 107 times greater than that of pristine Sb2S3. Consequently, Sb SA/PC-2 exhibits ultrahigh fast-charging capability (201.7 mAh g-1 at 20.0 A g-1) and ultralong cycling life (364.4 mAh g-1 at 5.0 A g-1 after 5000 cycles). Theoretical calculations reveal that the fast-charging capability can be attributed to the low migration barrier and increased number of active sites. Moreover, owing to the structural integrity of Sb single atoms, phase separation is effectively inhibited. This work is anticipated to open an avenue toward designing advanced electrode materials for ultrafast-charging SIBs. Assisted by the introduction of abundant carbon vacancies, extensive CS/CO chemical bonds are successfully designed. Benefiting from the establishment of abundant SbSC/SbOC interfacial chemical bonds, high-density Sb single atoms (31.4 wt%) are firmly anchored in the interior of carbon, with a high yield of 210.56 g per batch. This work provides a promising strategy to design advanced anodes for achieving ultrafast and ultrastable sodium-ion batteries. image