3D‐Printed Nanostructured Copper Substrate Boosts the Sodiated Capability and Stability of Antimony Anode for Sodium‐Ion Batteries

Abstract Sodium‐ion batteries (SIBs) represent a viable substitute to lithium‐ion batteries due to their affordability and resource abundance. For SIBs, antimony (Sb) shows potential as anode material but is impeded by the high volumetric variations. Here the challenges of Sb sodium storage by introducing the nanostructured Cu substrate for enhanced Sb adhesion and morphology optimization is addressed, which is realized by fused deposition modeling (FDM) printing of Cu substrate, subsequent high‐temperature sintering, and electrodeposition of Sb. In SIBs, the Sb deposited on three dimensional (3D) printed Cu substrate performs improved cycling stability compared with that of Sb@Cu with commercial Cu foil substrate, which can be attributed to the nanostructure of the 3D‐Cu substrate. Such architecture of 3D‐Cu induces the generation of pine‐leaf‐like Sb clusters to promote stability and kinetics, and it aids the adhesion between the Sb cluster and 3D‐Cu substrate for preventing the Sb detachment and restructuring the Sb cluster to the robust porous ligament‐channel Sb framework. The morphology evolution, (de)sodiation mechanism, and gas evolution are explored by ex situ scanning electron microscope, operando X‐ray diffraction, and operando differential electrochemical mass spectrometry separately. The developed Sb@3D‐Cu anode offers a flexible pathway for constructing 3D‐printed self‐supported electrodes for SIBs.