Enhancement of capacity of carbon-coated Si–Cu3Si composite anode using metal–organic compound for lithium-ion batteries

A carbon-coated Si–Cu3Si composite material is prepared using silicon and copper(II) d-gluconate powders by simple mechanical milling and pyrolysis, and is investigated as an anode material for lithium-ion batteries. In this process, the Cu3Si and pyrolyzed carbon uniformly adhere to the surface of the silicon particles. The cycling performance of the composite material exhibits a stable capacity of 850 mAh g−1 for 30 cycles. The improved cycling performance is attributed to the fact that the copper silicide and pyrolyzed carbon provide both a better electrical contact with the current–collector and a buffering effect for the volume expansion–contraction during cycling.