Integratable all-solid-state thin-film microbatteries.

Large-scale integration of microbattery systems on chips has long been hindered by the technical barrier between electrochemistry and microelectronics, particularly in terms of the compatibility of microbattery cells and their collective manufacturability. In this work, a silicon-based all-solid-state thin-film microbattery cell is developed at low temperatures for on-chip integration applications. Stress management at the interfaces covering both the resistance to interfacial fracture and the stress dissipation through strain regulation enables microbattery cells to deliver a high-rate performance (34.4 mA cm-2), fast charge-discharge properties (1,000,000 cycles at 20 mA cm-2), and high-temperature tolerance (150 °C) under zero stack pressure. An intrinsic relationship among lithium utilization ratio, strain, stress, and interface manifestation is uncovered. A collective microfabrication protocol for on-chip microbattery packs is proposed, resulting in a prototype of series-connected microbattery packs. This work focuses on practically addressing the technologies and challenges in engineering on-chip microbattery systems for large-scale integration.