Preparation and electrochemical performance of Cu₆Sn₅/CNTs anode materials for lithium-ion batteries

Abstract

Cu6Sn5/carbon nanotubes (CNTs) composite materials were synthesized by reductive co-precipitation method. Their morphologies, microstructures and electrochemical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), constant current charge/discharge tests, cyclic voltammetry tests (CV) and electrochemical impedance spectroscopy (EIS). The large surface area, excellent conductivity and mechanical properties of the CNTs reduced the agglomeration of alloy particles, buffered the stress of volume change and lowered the powdering rate of particles, simultaneously, maintaining the cycling stability and increasing Li+ transmissions and effectively whittling the contact resistance. The Cu6Sn5/CNTs composites alloy anode materials exhibited a better electrochemical performance and cycle life than those of any other composite alloy anode materials, demonstrating a capacity of 409 mAh/g after 50 cycles at voltage range of 0.02–1.5 V, at the current density 0.05 mA/cm2.