Electrochemical properties of Ni-based inert phases incorporated Si/graphite composite anode

Ni-based inert phases incorporated Si/graphite composite, prepared by thermal decomposition of a mixture of nickel stearate and Si/graphite composite, was investigated as an anode material for lithium-ion batteries. The first discharge and charge capacities of this material were 940 and 640 mAh g−1, respectively, with 72% of the first cycle coulombic efficiency. Back scattered electron image of the cross section of this material revealed that Ni-based inert phases, i.e., Ni and Ni2Si were finely dispersed in the Si/graphite matrix. Ex situ X-ray diffraction results indicated that those Ni-based inert phases were inactive against lithium, and they are believed to improve the electrical conduction network inside the active material and to alleviate to some extent the mechanical stresses associated with volume changes during cycling.