Cobalt-Phosphide-Modified Carbon-Coated Copper Current Collector for Stable Lithium Metal Deposition via Dendrite Suppression and Enhanced Ion Diffusion

In this study, a phosphide-functionalized interfacial layer was constructed on a 3D carbon-coated Co-modified copper current collector (Cu@C–Co) via a vapor-phase deposition technique, yielding a multifunctional Cu@C–Co–P architecture. This rational design synergistically integrates the high specific surface area of the hierarchical porous structure with the strong lithiophilicity of Cu 3 P, significantly reducing the lithium nucleation overpotential and enabling spatially confined lithium deposition within the 3D conductive framework. During cycling, an in situ-formed Li 3 P interphase with excellent ionic conductivity and mechanical robustness effectively suppresses dendritic growth and interfacial side reactions. Electrochemical evaluations demonstrate that the symmetric cells based on Cu@C–Co–P exhibit ultrastable cycling over 2600 h at 1 mA cm –2, while full cells maintain ∼90% capacity retention after 160 cycles at a high rate of 5 C. Moreover, the lithium-ion diffusion coefficient is enhanced by more than 28%. This work provides a multifunctional current collector design that simultaneously enables guided lithium deposition, interfacial stabilization, and fast ion transport, offering a promising pathway toward high-energy-density lithium metal batteries.