POS6-1324
Conformational Engineering of Polypeptide Binders for Thick Cathodes
When and Where
Nov 30, -0001
00:00 - 00:00
Room 301 (Grand Ballroom)
Presenter(s)
Hayoung Park (POSTECH)
Co-Author(s)
Abstract
Polyvinylidene fluoride (PVDF) is one of the dominant commercial binders in lithium-ion batteries owing to its chemical stability. However, impending restrictions on per- and polyfluoroalkyl substances necessitate alternatives. Furthermore, PVDF lacks polar functional groups, leading to poor interfacial adhesion that compromises the mechanical integrity of high-loading electrodes. In this work, we propose zein, a corn-protein, as a binder for thick cathode. Interestingly, 2 wt% zein successfully supported high-loading electrodes exceeding 6 mAh cm-2. This exceptional mechanical stability implies the formation of a robust macromolecular network within the electrode, as well as its strong interfacial bonding.
Conventional binder research has largely overlooked the binder morphology within the electrode; this study focuses on the physical conformation of the binder alongside its chemical composition. To control the random self-aggregation of zein driven by intermolecular hydrogen bonding, tannic acid (TA) was introduced to ensure uniform slurry dispersion. Small-angle X-ray scattering (SAXS) analysis revealed that TA alters intramolecular interactions, directly expanding the radius of gyration (Rg) of individual zein molecules. We demonstrated that the molecular conformation of the binder in the solution state directly modulates its final morphology within the electrode after slurry drying. This conformational expansion, synergistic with improved colloidal dispersion, significantly reduces charge transfer resistance. The expanded zein-TA framework effectively dissipates internal stress and is anticipated to secure accessible Li+ diffusion pathways by mitigating dense, insulating passivation on the active material surface during drying. This work establishes an electrode design paradigm of modulating the binder morphology through solution-state conformation, there by emphasizing the crucial yet overlooked role of macromolecular structures in electrode engineering.
Conventional binder research has largely overlooked the binder morphology within the electrode; this study focuses on the physical conformation of the binder alongside its chemical composition. To control the random self-aggregation of zein driven by intermolecular hydrogen bonding, tannic acid (TA) was introduced to ensure uniform slurry dispersion. Small-angle X-ray scattering (SAXS) analysis revealed that TA alters intramolecular interactions, directly expanding the radius of gyration (Rg) of individual zein molecules. We demonstrated that the molecular conformation of the binder in the solution state directly modulates its final morphology within the electrode after slurry drying. This conformational expansion, synergistic with improved colloidal dispersion, significantly reduces charge transfer resistance. The expanded zein-TA framework effectively dissipates internal stress and is anticipated to secure accessible Li+ diffusion pathways by mitigating dense, insulating passivation on the active material surface during drying. This work establishes an electrode design paradigm of modulating the binder morphology through solution-state conformation, there by emphasizing the crucial yet overlooked role of macromolecular structures in electrode engineering.
