The synergistic effects of combining the high energy mechanical milling and wet milling on Si negative electrode materials for lithium ion battery

• Published in: Journal of power sources Vol. 349; pp. 111 - 120
• Main Authors: Hou, Shang-Chieh, Su, Yuh-Fan, Chang, Chia-Chin, Hu, Chih-Wei, Chen, Tsan-Yao, Yang, Shun-Min, Huang, Jow-Lay
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2017
• Subjects: Anode; High energy mechanical milling; Lithium-ion battery; Wet milling; Lithium-ion battery; Anode; Si; Wet milling; High energy mechanical milling
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2017.03.024

The submicro-sized and nanostructured Si aggregated powder is prepared by combinational routes of high energy mechanical milling (HEMM) and wet milling. Milled Si powder is investigated by particle size analyzer, SEM, TEM, XPS and XRD as well as the control ones. Its electrode is also investigated by in situ XRD and electrochemical performance. Morphology reveals that combining the high energy mechanical milling and wet milling not only fracture primary Si particles but also form submicro-sized Si aggregates constructed by amorphous and nanocrystalline phases. Moreover, XPS shows that wet milling in ethanol trigger SiOCH2CH3 bonding on Si surface might enhance the SEI formation. In situ XRD analysis shows negative electrode made of submicro-sized Si aggregated powder can effectively suppress formation of crystalline Li15Si4 during lithiation and delithiation due to amorphous and nanocrystalline construction. Thus, the submicro-sized Si powder with synergistic effects combining the high energy mechanical milling and wet milling in ethanol as negative electrode performs better capacity retention. [Display omitted] •Submicro-sized Si powder is prepared by combination of HEMM and wet milling.•Submicro-sized Si powder is constructed by amorphous and nanocrystalline phases.•Submicro-sized Si electrode exhibits suppressed formation of crystalline Li15Si4.•Wet milling in ethanol triggers SiOCH2CH3 bonding on Si surface enhance SEI films.