A Polar Functional Binder With Molecular Clamp Strategy for Stabilizing High‐Voltage Nickel‐Rich Cathodes

Despite their potential for high‐energy‐density lithium‐ion batteries, high‐voltage nickel‐rich layered cathodes face critical challenges from interfacial degradation and bulk structural instability. Here, we design a novel polar‐functionalized polymer binder that molecularly integrates nitrile and ester functional groups to overcome these intrinsic limitations. Nitrile groups reversibly coordinate with high‐valence transition‐metal (TM) ions in nickel‐rich cathodes, significantly raising their migration energy barriers and suppressing Ni/Li cation disorder and surface rock‐salt phase reconstruction. Simultaneously, ester groups enhance the wettability and adhesion of the cathode, ensuring uniform binder coverage and strong particle bonding, which effectively accommodates the anisotropic volume evolution and mitigates microcrack formation in nickel‐rich secondary particles, resulting in the formation of a dense and chemically stable cathode–electrolyte interphase layer. Such coordination‐driven stabilization preserves the TM‐O 6 octahedral framework, mitigates oxygen release, and maintains interfacial integrity under harsh high‐voltage cycling. The obtained electrodes deliver 199.8 mAh g −1 with 83.0% retention after 500 cycles at 1.0 C and 144.7 mAh g −1 after 700 cycles at 5.0 C, far surpassing conventional PVDF‐based electrodes. This work demonstrates the power of polar coordination binders in modulating cathode interfaces and achieving durable operation of high‐energy‐density lithium‐ion batteries.