Y. Zhu, S. Wang *, Y. Ma, X. Wang, Y.H. Fu, L.S. Wu, S.H. Liao, Z.H. Ren, M.T. Zhang, Z.C. Xu, Y.P. Xie * and Z.-S. Wu *

Energy Storage Materials, 2025, accepted.

In the 5G era, demand for flexible, wearable, and implantable microelectronics is soaring, driving the urgent need for high-capacity, flexible and integrated microbatteries (MBs). Traditional battery designs and fabrication strategy fail to meet these comprehensive requirements, particularly in terms of flexibility and customizability for multi-bipolar battery integration. Herein, we demonstrate the large-scale screen-printing production of planar monolithically integrated solid-state lithium ion MBs (LIMBs), with key characteristics of superior areal capacity, excellent output voltage, and exceptional flexibility. The resulting individual LIMB delivers ultrahigh areal capacity of 1431 μAh cm-2, ultralong cyclability without obvious capacity loss after 8000 cycles, and excellent dimensional customizability. Attributing to the flexibility of all components, especially solid-state electrolyte, together its strong interfaces with cathode and anode, our solid-state LIMBs demonstrate exceptional mechanical flexibility, without performance degradation after repeated bending. Moreover, we constructed an integrated energy-storage module consisting of five bipolar LIMB devices, which significantly boosts the output voltage to 12.5 V and maintains exceptional flexibility, thanks to its uniqueness of coplanar design and precise spacing arrangement. Our integrated LIMBs function as a flexible watchband, providing uninterrupted power to a wristwatch. This adjustable-voltage MB technology marks a breakthrough in power management and shows great promise toward flexible and wearable electronics.