Preparation and electrochemical characterization of tin/graphite/silver composite as anode materials for lithium-ion batteries

The tin/graphite/silver (Sn/G/Ag) composite was prepared by high-energy mechanical milling (HEMM) for the first time. The composite powders consisted of electrochemically active Sn, Ag₄Sn phases which were uniformly distributed on the surface of the graphite particles. The formation of Ag₄Sn alloy phase and the uniform distribution of the active particles could accommodate the large volume changes during cycling. X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM) and scanning electron microscopy (SEM) were used to determine the phases obtained and to observe the microstructure and dispersion of particles. In addition, cyclic voltammetry (CV) and galvanostatic discharge/charge tests were carried out to characterize the electrochemical properties of the composite. The composite electrodes exhibited an initial capacity of 1154 mAh g⁻¹ and maintained a reversible capacity of above 380 mAh g⁻¹ for more than 100 cycles.