A copper silicide nanofoam current collector for directly grown Si nanowire network and their application as lithium-ion anodes

Silicon nanowires (Si NWs) have been identified as an excellent candidate material for the replacement of graphite in anodes, allowing for a significant boost in the capacity of lithium‐ion batteries (LIBs). Herein, high‐density Si NWs are grown on a novel 3D interconnected network of binary‐phase Cu‐silicide nanofoam (3D CuxSiy NF) substrate. The nanofoam facilitates the uniform distribution of well‐segregated and small‐sized catalyst seeds, leading to high‐density/single‐phase Si NW growth with an areal‐loading in excess of 1.0 mg cm−2 and a stable areal capacity of ≈2.0 mAh cm−2 after 550 cycles. The use of the 3D CuxSiy NF as a substrate is further extended for Al, Bi, Cu, In, Mn, Ni, Sb, Sn, and Zn mediated Si NW growth, demonstrating the general applicability of the anode architecture.