High-cycling-stability of nanosized sandwich structure silicon/graphene composite as anode for lithium-ion batteries

Abstract

The nanosized sandwich structure silicon/graphene composite anode material was designed to enhance anode performance for lithium-ion batteries (LIBs) by a facile method of mechanical ball milling. The structure and morphology of the materials were investigated by X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). The electrochemical properties of this composites electrode were studied by a series of electrochemical tests. As anode of LIBs, the composite material exhibited a high initial reversible capacity of 2189.7 mAh·g-1 at a current density of 1000 mA·g-1, and showed an enhanced cyclic performance with a reversible capacity of 1212.9 mAh·g-1 after 100 cycles. The performance improvement be attributed that as a good matrix, the graphene sheets mitigated the volume expansion/shrinkage of silicon during the lithiation/delithiation processes and increased electrical conductivity of anode materials.