Flexible 3D Interlocking Lithium‐Ion Batteries

Abstract Highly deformable and advanced flexible lithium‐ion batteries (LIBs) are considered to be a promising power source for flexible electronics. However, despite tremendous efforts to achieve flexibility, battery performance still lags behind the commercial standards. Here, a flexible 3D interlocking LIB via a one‐step patterning process of a preassembled cell under industrial electrode fabrication conditions, to satisfy commercial viability, is demonstrated. The 3D interlocking full‐cell with a high electrode loading level demonstrates excellent cycle performance without any degradation during the 5000 times flexing process. The tightly connected cathode and anode increase the contact area and prevent the current issues of flexible batteries such as delamination, electrode cracking, and lithium plating. This study on flexible batteries therefore suggests the 3D interlocked architecture lends itself to the design of highly deformable energy storage devices.