Sputtered copper coating on silicon/graphite composite anode for lithium ion batteries

A sputtered copper coating on a silicon/graphite composite is investigated as an anode material for lithium ion batteries (LIBs). Characterization of the material has been performed by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). Results show that the thickness of the copper on the nano-Si/graphite composite anode is controlled by the duration of copper sputtering. A sputtered copper coating of approximately 12 nm thickness improves the rate capacity, maximum energy density and the elevated temperature cycling performance of LIBs with silicon/graphite anodes. The presented results confirm that the modification provided by sputtered Cu to the morphology of the solid/electrolyte interface of the anode surface is of interest to the next generation of high performance LIBs. (C) 2014 Elsevier B. V. All rights reserved.