Insights into the role of lithiophilic Sb dopant in porous Cu-Sb current collectors for stabilizing Li plating in Li-metal batteries

Porous Cu current collector is promising for Li-metal batteries (LMBs) due to its ability to accommodate volume expansion and homogenize current distribution. However, its intrinsic lithiophobicity and lack of functionality impede practical applications. Herein, we fabricated Sb-doped porous Cu solid-solution current collectors with different Sb concentrations (0, 0.5, 1.0 and 1.5 at.%) via a Zn-mediated vapor phase alloying and dealloying route. Multiple in situ techniques (X-ray diffraction, infrared absorption spectroscopy, mass spectrometry and impedance spectroscopy) combined with theoretical calculations reveal that Sb doping modulates the Li plating/stripping kinetics and solid electrolyte interphase (SEI) evolution. Moreover, Sb incorporation enhances the Li + transference number, reduces the activation energy for Li deposition, and lowers the interaction energy of Li atoms on the lithiophilic Sb-doped Cu substrate. These effects promote uniform Li nucleation and deposition while fostering a more stable SEI. Noticeably, the P-Cu 98.5 Sb 1.5 current collector delivers superior stability, high coulombic efficiency, and better electrochemical performance in both half and full cells, as benchmarked with the undoped P-Cu counterpart. This work elucidates the mechanistic role of Sb doping and demonstrates the design of lithiophilic porous current collectors for high-performance LMBs. • Porous Cu-Sb solid solution was fabricated through the combination of VPA with VPD. • Sb incorporation reduces the barriers of Li nucleation and uniformizes Li plating. • The addition of Sb promotes the generation of inorganic components in SEI. • Porous lithiophilic Cu-Sb electrode displays superior electrochemical performance.