A Printed Zinc‐Ion Microbattery with Extended Shelf Life and Durability for Energy Autonomous Sensors

ABSTRACT Printed zinc‐ion batteries (ZnIBs) hold significant promise for micro‐energy storage systems, particularly for powering the Internet of Things (IoT). However, their practical viability is limited by short shelf‐life and poor cycling stability, arising from interfacial degradation, dendrite formation, parasitic side reactions on the Zn anode, and dissolution of cathode material. Addressing these challenges is essential for enabling robust and long‐lasting ZnIBs for energy‐autonomous devices. Here, we report a durable, fully printed Zn‐ion microbattery based on aqueous‐ink‐manufactured microelectrodes, featuring graphene platelets decorated micron‐sized zinc powder (Gr‐µZn) anode and a nitrogen‐doped carbon@manganese oxide (MnO@NC) composite cathode. The printed Gr‐µZn architecture ensures adequate electrical conductivity (2.6 Ω), uniform Zn deposition with low overpotentials (∼50 mV at 1 mA/cm 2 after 500 h), good structural integrity and stable operation with low polarization. Furthermore, the fully printed ZnIB exhibits an areal capacity of 1.5 mAh/cm 2 (99.8 mAh/g) and an energy density of 2 mWh/cm 2 , along with an extended shelf‐life, which are competitive. To demonstrate practical feasibility, we powered a wearable heart‐rate sensor using a printed ZnIBs, which delivered a stable output voltage with ∼70 h of continuous operation. Our work demonstrates a scalable and sustainable platform for high‐performance printed ZnIBs, advancing their integration into self‐powered health monitoring devices.