초록 |
Silicon based anodes suffer from severe volume expansion during the lithiation and delithiation, which cause high stress and pulverization, resulting degradation of cycle life in lithium ion batteries. According to the previous reports, poly(acrylic acid) (PAA) binders can accommodate the volume expansion of Si particles due to reversible cross-linking nature between carboxylic groups. However, this reversible cross-linking is often susceptible to the environmental changes. Herein, we report for the first time that PAA functionalized with photo-cross-linkable benzophenone moiety (PAA-BP) with an aim to enhance the cycle life of batteries. PAA-BP binders form irreversible cross-linked structure by covalent C-C bond upon UV-irradiation, leading to the enhanced mechanical and chemical stability that endure the environmental changes. We demonstrate PAA-BP binders effectively bind Si particles together and suppress the large volume change with superior cycle stability and high capacity. |