Design guidelines for body-conformable aqueous zinc-based batteries

Advanced wearable medical devices represent a key direction for transforming traditional healthcare systems, where aqueous zinc-based batteries (AZBs) with inherent electrochemical safety serve as promising flexible energy storage solutions. However, conventional battery designs remain too rigid for conformal integration. This review presents a system-level design guideline for body-conformable AZBs, linking application-specific mechanical principles with scalable fabrication, material selection, and parameter optimization. We compare physical models that relate filler content, orientation, and contact topology to effective conductivity, clarifying how deformation-induced changes in conductive-network connectivity govern the electromechanical performance of stretchable electrodes. Subsequently, we introduce innovative structural strategies that impart device-level stretchability without relying on the intrinsic stretchability of materials and analyze quantitative relationships between electrode geometric parameters and mechanical properties. Finally, we highlight emerging advanced cathode chemistries, including sulfur cathodes, four-electron iodine redox chemistry, and electrolytic MnO₂ cathodes that have the potential to overcome the energy-density bottleneck, as well as polymer cathodes and air cathodes with high potential for body-conformable applications. This review offers systematic design principles and accelerates the translation of AZBs toward body-conformable healthcare electronics.