Author(s)

Norihiro Shimoi^1*, Masae Komatsu¹, Yasumitsu Tanaka², Kazuyuki Tohji¹

¹Graduate School of Environmental Studies, Tohoku University, Sendai, Japan.
²Institute for Excellence in Higher Education, Tohoku University, Sendai, Japan.

An active anode material for Li-ion batteries was synthesized using a simple mechanochemical process to minimize the large change in Si volume observed during charge-discharge operation and to compensate for the associated irreversible loss of Li or irreversible capacity loss, which are obstacles to achieve high-performance electrochemical properties during charge-discharge. The composite was mechanochemically milled with Si, lithium oxide, and copper oxide as raw materials; the composite contains Si nanoparticles, amorphous silicon monoxide, and Si-Li or Si-Cu alloy compounds, and it exhibits improved electrochemical properties. In particular, this composite achieved a better capacity retention, higher coulombic efficiency (over 100%), and longer cycling performance than Si alone, indicating considerable optimization of the electrical and ionic conductivity in the composite. The developed method allowed for control of the Li content to compensate for the lack of Li ions in the composite, and the cycling performance was optimized using the Cu alloy, oxide, and Li compounds within the composite.

Mechanochemical Process, Nanocomposites, Metamorphosed Composites, Lithium-Ion Battery, Silicon Active Material

Shimoi, N. , Komatsu, M. , Tanaka, Y. and Tohji, K. (2018) Mechanochemically Metamorphosed Composites of Homogeneous Nanoscale Silicon and Silicate Oxides with Lithium and Metal Compounds. Materials Sciences and Applications, 9, 111-125. doi: 10.4236/msa.2018.91008.