All 3D Printed Load‐bearing Zn‐ion Hybrid Supercapacitors

ABSTRACT The rapid development of smart equipment and emerging energy technologies demands structural components that are lightweight, mechanically robust, energy‐dense, and geometrically versatile. Yet load‐bearing electrochemical energy‐storage devices remain constrained by the challenge of simultaneously improving electrode activity and ion/electron transport while maintaining mechanical robustness. Here, we report a low‐cost 3D printing strategy for the integrated fabrication of load‐bearing Zn‐ion hybrid supercapacitors using functional core–shell continuous carbon fiber prepreg filaments, where “fully 3D‐printed” refers to the one‐step additive manufacturing of the structural framework (electrodes and electrolyte matrix) followed by necessary post‐printing treatments (supercritical foaming and gelation) to activate electrochemical performance. On the electrode side, supercritical fluid‐assisted laser‐induced graphitization converts continuous carbon fiber bundles into hierarchical porous graphene cathodes, delivering a 2.4‐fold increase in areal capacitance over conventional LIG electrodes. On the electrolyte side, a biphasic PP/PVA semi‐solid electrolyte is engineered by supercritical foaming to construct interconnected open ion‐transport channels, increasing the ionic conductivity from 0.5 to 4.2 mS cm − 1 . Together, these designs enable fully 3D‐printed continuous fiber devices with integrated mechanical load‐bearing and electrochemical energy‐storage functions. This work establishes a versatile, cost‐effective, and scalable route toward multifunctional structural power sources for next‐generation integrated devices.