Large‐Scale Manufacturing of Pattern‐Integrated Paper Li‐Ion Microbatteries through Roll‐to‐Roll Flexographic Printing

Abstract Electrode architectures significantly influence the electrochemical performance, flexibility, and applications of lithium‐ion batteries (LiBs). However, the conventional bar coating for fabricating electrodes limits the addition of customized architecture or patterns. In this study, as a novel approach, patterns are integrated into electrodes through large‐scale roll‐to‐roll (R2R) flexographic printing. Additionally, flexible, recyclable, and biodegradable paper are innovatively used as a printing substrate during printing LiBs manufacturing, which exhibited superior printability. Moreover, the paper is modified with a thin‐layer Al 2 O 3 to function as the separator in the printed LiB. The Al 2 O 3 ‐coated paper enables an admirable wettability for printing, excellent mechanical properties for high‐speed R2R manufacturing, and outstanding thermal stability for the safe and stable operation of LiBs. The assembled paper cells exhibit nearly 100% discharge capacity retention after 1000 cycles at 3 C and outstanding rate performance. This work inspires future large‐scale microbatteries manufacturing integrated with high‐resolution architecture designs.