Silicon diphosphide (SiP2), a next-generation anode material for lithium ion batteries, exhibits a high theoretical specific capacity (2900 mAh g-1) but suffers from rapid capacity fading due to its large volume change and the formation of ionic insulator LiP. Herein, SiP2 composites with carbon, acting as a buffer to accommodate large volume change of phosphides, were prepared with and without chemical bonding between carbon and phosphide. The composite with chemical bondings shows excellent cycling stability, while the composite without the chemical bondings shows continuous decay in capacity. Furthermore, our study shows that the SiP2–nanocarbon interface can facilitate fast ion conduction, overcoming the issues associated with the ionically insulator LiP. Thus, the present study provides novel insights into the chemical bonding as well as interface as a fast ion conduction pathway in the SiP2/nanocarbon composite with good electrochemical performances. More details will be discussed at the meeting.