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

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.