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

△ [14a-A36-12] Discharge and Charge Capacity Characteristics of Li-ion Batteries
Using Si Nanopowder Electrode Fabricated from Si Swarf : Si Size-Dependence

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

Keywords:Li-ion batteries, Anode, Si nanopowder

Si nanopowder have been expected as high capacity anode materials for Li-ion batteries. We fabricated Si nanopowder from Si swarf and achived 1700 mAh/g discharge capacity in the 100th cycle. In the case of using small crystallite size Si nanopowder, the average of the coulombic efficiency (high charge and discharge cuurent) and cyclability increased. In the case of using large crystallite size Si nanopowder, expansion and contraction of Si nanopowder derived from charge and discharge was larger and the conductivity pass of a part of Si nanopowder diappeared. Those caused that discharge capacity more than 0.5 V decreased, resulting in low cyclability.