Designing Adaptive Binders for Microenvironment Settings of Silicon Anode Particles

Abstract This study reports the concept of an “adaptive binder” to address the silicon anode challenge in Li‐ion batteries. Binders exhibit adaptable capabilities upon gradual changes in the microenvironments surrounding silicon particles during anodic expansion–shrinkage cycles. Long, flexible binder chains are repositioned and reoriented upon the gradual formation of Si‐micro‐environments (Si‐μ‐env) during the early battery cycles. At this stage, the chemical interactions between the polymeric binders are reversible hydrogen bonds. As the Si‐μ‐env become stably set by repeated battery cycles, the chemical interactions exhibit reversible‐to‐irreversible transitions by the formation of covalent linkages between the binder polymers at the later stage of cycles. The binder polymer showing the aforementioned adaptive properties is hyaluronic acid, which has never been explored as a silicon‐…