A new photo-cross-linkable poly(acrylic acid) (PAA) polymer functionalized with a photoreactive benzophenone group (PAA-BP) was synthesized and examined as a binder for Si-based anodes. Upon UV irradiation, the PAA-BP binders formed an irreversible cross-linked structure through the formation of a new three-dimensional C–C bond network between the benzophenone moiety and the PAA backbone. The photo-cross-linked PAA-BP binder demonstrated a marginal volume expansion (38%) after full lithiation, compared to conventional binders and this resulted in an improved cycle performance of the Si anode over 100 cycles with a high reversible capacity of ca. 1600 mA h g−1. We attributed this phenomenon to the enhanced mechanical properties of the photo-cross-linked PAA-BP binder, which were evaluated using nanoindentation and swelling measurements.
合成了一种新的可光交联聚(
丙烯酸)(P
AA)聚合物,该聚合物被光活性苯甲酮基团(P
AA-BP)功能化,并作为
硅基负极的粘合剂进行研究。在紫外线照射下,P
AA-BP 粘合剂通过苯甲酮部分与 P
AA 主链之间形成新三维 C-C 键网络,形成不可逆的交联结构。与传统粘合剂相比,光交联的 P
AA-BP 粘合剂在完全
锂化后仅表现出38%的微小体积膨胀,这导致 Si 负极在超过100个循环中的循环性能得到改善,具有约 1600 mA h g−1 的高可逆容量。我们将这一现象归因于光交联 P
AA-BP 粘合剂的机械性能增强,采用纳米压痕和膨胀测量对其进行了评估。