Silicon diphosphide (SiP2), a next-generation anode material for lithium ion batteries, exhibits a high theoretical specific capacity (2900 mAh g−1), however, its capacity is rapidly faded due to its large volume change. An effective way to improve the electrochemical performances of SiP2 is to composite with carbon buffer. In the composite, chemical bonds of SiP2 and carbon are expected to maintain SiP2 to carbon connections during cycling, thereby, provide electron conduction pathways even under the volume change of SiP2. However, effect of the chemical bonds is not clearly understood. Thus, it is very important to distinguish contributions of the carbon buffer and chemical bonds to the electrochemical properties of SiP2. Herein, SiP2 composites with nanocarbon are prepared with and without chemical bonds between SiP2 and carbon by controlling ball milling parameter with an aim to investigate respective contribution of the carbon buffer and chemical bonds to the electrochemical properties of SiP2. The SiP2/nanocarbon composite with P–O–C and Si–O–C chemical bonds shows great improvement of electrode performances over the composite without the chemical bonds. Furthermore, the SiP2–nanocarbon interface is found to facilitate fast ion conduction, overcoming the issues associated with the ionically insulative LiP.
Bibliographical noteFunding Information:
This work was supported by the Korea Institute of Energy Technology Evaluation and Planning and the Ministry of Trade, Industry and Energy of the Republic of Korea (No. 20172420108590 ). And this work was supported by the Technology Innovation Program ( 10062226 , Development of flexible hybrid capacitor (0.25 mWh/cm 2 ) composed of graphene-based flexible electrode and gel polymer electrolyte with high electrolyte uptake) funded by the Ministry of Trade, Industry & Energy, Korea.
© 2019 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering