Surface-Anchored Fluorine-Free Polynorbornene Binders for High-Voltage Stability of High-Nickel Cathodes
발표자
김승현 (서울대학교)
연구책임자
심지민 (서울대학교)
공동저자
김승현 (서울대학교), 심지민 (서울대학교)
초록
내용
High-nickel cathodes in high-energy-density lithium-ion batteries require high-voltage stability and lean binder content. Conventional poly(vinylidene fluoride) exhibits poor adhesion and environmental concerns as per- and polyfluoroalkyl substances. We propose a fluorine-free polynorbornene-based terpolymer binder featuring a novel chemical anchoring mechanism. This binder undergoes an in-situ ring-opening reaction with the cathode surface, forming covalent ester linkages that enhance mechanical adhesion and enable stability at 2 wt% binder content. This anchoring facilitates 4.5 V operation by forming a protective layer that suppresses interfacial degradation. Post-mortem analyses show that the binder network suppresses layered-to-rock-salt phase transitions and captures dissolved transition metals to inhibit cross-electrode degradation. This work establishes covalent chemical anchoring as a design principle for sustainable, high-performance binders in next-generation batteries.