Advances in micro lithium-ion batteries for on-chip and wearable applications

Miniature power sources have gained widespread attention and accelerated progress with portable, wearable, and integrated electronic technologies. Micro lithium-ion batteries(μLIBs) featured small size, lightweight, high capacity, and long cycle life, which also offer stability, safety, and compatibility with microfabrication, make them the ideal choice for energy storage. Researchers have engaged in the performance optimization and application expansion of μLIBs, especially in the on-chip μLIBs with compatible integration for microdevices and flexible μLIBs for wearable applications. This paper reviews the working principles, performance metrics, and design methodologies of μLIBs, highlighting the advantages of the architecture design. Typical materials and fabrication methods are introduced, and their effects on the device performance and system integration are analyzed. The developments of μLIBs are summarized from the perspective of 3D architecture design, to the on-chip and wearable applications. At last, the challenges and the prospects that inspire further research and development of μLIBs are concluded.