Nanosized silicon-based composite derived by in situ mechanochemical reduction for lithium ion batteries

Composite consisting of nanosized silicon, Li₄SiO₄ and other lithium-rich components was synthesized using high energy mechanical milling (HEMM) method. The reactive milling of SiO with lithium metal resulted in the oxidation of lithium and silicon, and reduction of SiO. X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM) were used to determine the phases present in the composite. In addition, cyclic voltammetry (CV), along with constant current discharge/charge tests, was used to characterize the electrochemical properties of the resultant material. Compared with pure SiO and pure silicon as anode materials, the as-prepared composite demonstrated larger capacity and superior cyclability even at high C-rate.