[17p-PB05-1~6] 16.1 Fundamental properties, evaluation, process and devices in disordered materials

[17p-PB05-3] Synthesis of the silicon composites as active materials by mechanochemical process with 3D ball-millimg

〇Norihiro Shimoi¹, Hirotaka Aonuma¹, Masakuni Satou², Yasunori Watanabe², Akira Hirakawa² (1.Tohoku Inst., 2.KAMEYAMA Iron works)

Keywords:Lithium-ion secondary battery, 3D ball-milling, anode active material

To minimize the large change in Si volume observed during charge–discharge operation and compensate for the irreversible formation of a Si–Li component, which are obstacles to achieving high-performance electrochemical properties, an active anode material was synthesized by a simple mechanochemical grinding process. The composite comprising Si, lithium oxide, and copper oxide has Si nanoparticles, amorphous silicon monoxide, and Si–Li or Si–Cu alloy compounds, and exhibits improved electrochemical properties. In particular, this composite achieved 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. As a result, the developed method allowed control of the Li content to compensate for the lack of Li ions in the composite, with the cycling performance optimized using the Cu alloy, oxide, and Li compounds within the composite.