Carbon-coated disproportionated SiO composite as anode materials for lithium-ion batteries

SiO is one of the most attractive anode materials for lithium-ion batteries due to its abundance and high theoretical specific energy density. However, the practical applications of SiO are seriously limited by its volume expansion and poor electrical conductivity. Herein, based on disproportionated SiO (mSiOx), a uniform and compact polyaniline carbon coating was prepared on the surface of mSiOx particles by in-situ polymerization with phosphoric acid as the reaction medium. Compared with uncoated mSiOx, the mSiOx@C composite presents excellent electrochemical stability after long cycles, although its initial columbic efficiency is slightly reduced. Physical characterization and electrochemical tests demonstrate that the carbon layers are successfully doped with N and P elements, and that the electrochemical properties of mSiOx@C composite are strongly affected by the relative content of carbon and its morphology. The half-cell experiment shows that the mSiOx@C anode can deliver a discharge specific capacity of 682 mAh g-1 after 200 cycles at a current density of 1 A g-1.