Ligand-Anchoring\nEffect of a PAA/PVDF-Cross-Linked\nBinder Promoting Interfacial Stability and Electrochemical Performance\nof a Cathode Material

Lithium-ion batteries (LIB) are extensively\nutilized\nacross industries\nfor their rechargeable nature, but capacity degradation during charge/discharge\ncycling poses the risk of battery failure. The LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub> (NCM811) cathode material\nencounters challenges in maintaining high capacity and cycling performance\ndue to cation mixing, ion migration, and electrolyte chemical reactions.\nWhile the conventional inorganic coating layer offers some physical\nprotection, it is susceptible to detachment. We introduce organic\npoly(acrylic acid) (PAA) and adhesive polyvinylidene fluoride (PVDF)\ncross-linked to form a composite cross-linked adhesive. The combination\nof PAA and PVDF improves the viscosity of the adhesive and enhances\nthe bonding strength of the cathode material. The C=O group in PAA\nforms coordination bonds with transition metals, creating a coordinated\nanchoring effect that enhances the stability of the cathode structure.\nThe reversible ion exchange between H<sup>+</sup> of −COOH\nand Li<sup>+</sup> promotes lithium-ion transport at the electrode\ninterface, enhancing electrochemical performance. After 200 cycles,\nthe capacity retention under 1C conditions reached 90.20%.