3D-printed topological-structured electrodes with exceptional mechanical properties for high-performance flexible Li-ion batteries

A vital aspect in advancing flexible batteries is the development of flexible electrodes capable of enduring repeated stretching while upholding satisfactory electrochemical performance. Thus, adopting a systematic and efficient approach to structural design and fabrication becomes imperative. In this study, we introduce an optimal structural design achieved through topology optimization and fabricate flexible electrodes via 3D printing, representing a departure from traditional design and manufacture methodologies in the development of flexible electrodes for batteries. Our research underscores the impressive mechanical strength of these topologically-structured electrodes (TSEs), validated through rigorous finite element analysis (FEA) and tensile strength testing. The results of both the stretch deformation and twist deformation analysis on the TSEs and the conventional mesh-structured electrodes (MSEs) show that the peak strain and stress of TSEs are much lower than those of MSEs. Notably, even under 50 % stretching, the TSEs maintain structural integrity, contrasting sharply with conventional mesh-structured electrodes (MSEs) and flat film electrodes which often crack under similar conditions. Moreover, after enduring 50 cycles of stretching, the TSEs retain an outstanding 98 % of their original capacity, surpassing MSEs which retain only 80 % of their capacity. These findings highlight the significant potential of topologically designed flexible electrodes, offering promising avenues for the development of stretchable and flexible energy storage devices such as wearable tech and bio-integrated electronics.