Ashland Developmental Binder for High Capacity Si-Containing Anodes

摘要

Silicon can be used for anodes in lithium ion batteries and provides a very high specific capacity at 4,200 mAh/g. However, very large volume changes associated with lithiation (up to 400%) during charge-discharge lead to rapid degradation and disconnection in composite electrodes, typically resulting in poor cycle life. The volume changes also result in large coulombic inefficiencies associated with the continual formation of SEI layers on freshly exposed surfaces. The binder used in cell fabrication plays an important role to control the volume expansion for high energy density Silicon electrodes, leading to improved cycle life.Considerable efforts have been made to control the volume expansion by use of novel binder systems that provide "re-healing" characteristic to the Silicon electrode. Ashland's developmental binder is designed to provide not only excellent processing abilities to make uniform slurry, smoothly coated anodes with good adhesion and flexibility, but results in cells that perform very well for various key commercial high capacity Silicon substrates.