ADDITION OF SPECIALLY DESIGNED SIO- CNF AND SI-CNF COMPOSITES TO IMPROVE CAPACITY AND RATE PERFORMANCES OF ANODIC GRAPHITE FOR LI-ION BATTERIES

摘要

Silicon is attractive material because of the higher capacity (4200 mAh/g) than graphite (372 mAh/g) as an anodic material of Li-ion battery (LIB). Nevertheless, silicon anode has not yet been commercialized because of the large volume expansion by 400% upon insertion and extraction of lithium ions, leading to internal cracks in the structure of its particle. The internal cracks cause poor contacts between the Si particles and current collector, and thus, Si anode shows poor cycle performances. Recently, hybridizations of Si or SiO with other materials have been studied in order to improve electrochemical properties. However some problems have still remained until now such as complicated manufacturing process of active material, difficulty of mass production, high cost, and so on.