[14a-A36-1~14] 1.4 Energy conversion, storage, resources and environment

[14a-A36-11] Mechanism of Property Improvement of Si Nanopowder Electrode by Addition of FEC and C Coating, and Fabrication of Si Nanopowder from Si Swarf

〇Taketoshi Matsumoto¹, Katsuya Kimura¹, Hikaru Kobayashi¹, Hirotomo Nishihara², Takatoshi Kasukabe², Takashi Kyotani² (1.ISIR, Osaka Univ., 2.IMRAM, Tohoku Univ.)

Keywords:silicon, Li ion battery, nanoparticle

Si swarf which is produced during the slicing process of Si ingots and treated as industrial waste was milled to Si nanopowder at a reduced cost, and was applied to an active material of Li ion batteries with high charge and discharge capacity. Addition of 10~15 wt% FEC to electrolyte solution suppressed peeling-off Si due to volume change during lithiation. C-coating of Si nanopowder with the C/Si ratio of 0.1~0.21 also suppressed the peeling-off of Si. The charge capacity of 1610 mAh/g in the 100th cycle was achieved by the optimized addition of FEC and C-coating of Si nanopowder.