Electrochemical properties of Si/Ni alloy–graphite composite as an anode material for Li-ion batteries

• Published in: Electrochimica acta 2005-09, Vol.50 (28), p.5561-5567
• Main Authors: Park, Min-Sik, Lee, Yong-Ju, Rajendran, S., Song, Min-Sang, Kim, Hyun-Seok, Lee, Jai-Young
• Format: Article
• Language: English
• Subjects: Anode; Applied sciences; Composite material; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; Graphite; Lithium-ion battery; Nickel; Silicon
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2005.04.042

Si/Ni alloy and graphite composites were synthesized using arc-melting followed by high energy mechanical milling (HEMM). Alloy particles comprising of NiSi 2, NiSi and Si phases were distributed finely and uniformly on the surface of graphite in the composites obtained after HEMM. The composite containing 60 wt.% of Si/Ni alloy exhibited a stable capacity of ∼780 mAh/g. Fourier transform infrared spectroscopy (FTIR) analysis confirmed that some bonds were formed between alloy and graphite after HEMM, which appeared to retain the electrical connection between alloy and graphite during cycling. X-ray diffraction (XRD) analysis indicated that NiSi 2 and NiSi phases, which acted as an inactive alloy matrix remained invariant during charge and discharge. In addition to NiSi 2 and NiSi phases, disordered graphite layers also played the role of media for the accommodation of large volume change of Si during cycling. The large reversible capacity and good cycleability showed that Si/Ni alloy and graphite composite could be an alternative to conventional graphite-based anode materials for lithium-ion secondary batteries.