Mechanical‐Thermal Decoupling Engineering Unlocks Ultra‐Stable Dry Thick Iodine Cathodes for Ah‐Level Zinc‐Based Pouch Batteries

Abstract

ABSTRACT Solvent‐free dry processing is ideal for fabricating thick iodine electrodes, but limited by slow kinetics and poor cycling stability. Herein, we reveal that, under continuous high‐shear processing, the coupled effects of uncontrolled mechanical stress and frictional heating destroy mass‐transport channels and induce silent iodine loss. Inspired by low‐frequency mild mechanical actuation in respiratory systems, a targeted energy intermittent release strategy based on water‐cooled pulse shearing is proposed to achieve precise decoupling and regulation of mechanical force and frictional heat accumulation. It is revealed that maintaining energy input below the thresholds of carbon host structure damage and iodine desorption, avoids micro‐scale “pore‐like” structure exposed to the cracking of low‐crystallinity carbon, thereby preserving strong van der Waals confinement between carbon and iodine, fundamentally preventing abnormal iodine migration. Concurrently, regulating the energy within the window between PTFE fiber formation and fracture, contrasts a uniform and stable thick iodine electrode at the micro‐macro scale, which enables over 50000 stable cycles at 100 C and an ultra‐high area capacity of 16.27 mAh cm −2 based on 82.84 mg iodine cm −2 iodine loading. Importantly, a ≈1.2 Ah pouch cell even retains 98.5% capacity after 300 cycles at 2 C, demonstrating the scalability and practical viability of the strategy.