Synergistic 3D Porous Architectures and Halogen Redox Chemistry for High‐Energy and High‐Power Microbatteries

ABSTRACT Planar on‐chip microbatteries (MBs) with high‐capacity electrodes and environmentally benign architectures are essential for powering next‐generation system‐on‐chip and miniaturized electronic devices. However, their limited areal capacity and poor rate performance remain major barriers to practical deployment. Here, we present a dual strategy that combines 3D porous Ni scaffolds with halogen redox chemistry to overcome these challenges. The 3D Ni scaffolds, fabricated using a dynamic hydrogen bubble template method, enable efficient loading of Zn anodes and polyaniline (PANI) cathodes, yielding more than a 100% enhancement in areal capacity, together with substantial improvements in rate capability and cycling stability in Zn‐ion MBs. Beyond structural engineering, the incorporation of ZnI 2 into a Zn(CF 3 SO 3 ) 2 gel electrolyte activates reversible halogen redox chemistry (I − /I 3 − ), further elevating performance. Notably, 3D Zn//I 2 MBs achieve areal capacities of 150 µAh cm − 2 , an areal energy of 142.53 µWh cm − 2 , and an areal power of 3443.59 µW cm − 2 at high areal currents (∼ 5 mA/cm 2 )—representing a step‐change in performance that outperforms many state‐of‐the‐art on‐chip energy storage systems. Systematic multi‐modal experimental validation reveals that the synergy between 3D electrode structuring and halogen redox chemistry governs ion diffusion, charge‐transfer kinetics, and long‐term durability.