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

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 ZnI₂ into a Zn(CF₃SO₃)₂ gel electrolyte activates reversible halogen redox chemistry (I^-/I₃ ^-), further elevating performance. Notably, 3D Zn//I₂ 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/cm²)-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.