3D-Printed Hierarchically Porous MOF-Derived Cathodes for Realizing High-Performance Flexible Quasi-Solid-State Aqueous Zinc–Cobalt Batteries

Rechargeable aqueous Zn-ion batteries hold significant promise for wearable electronics due to their intrinsic safety and eco-friendliness, yet cobalt-based cathodes remain constrained by poor conductivity and sluggish kinetics. Addressing these limitations, we developed 3D-printed (3DP) hierarchically porous MOF-derived cathodes for aqueous zinc–cobalt (Zn–Co) batteries via three synergistic innovation technology pathways: (i) ZIF-67-derived nitrogen-doped carbon-coated Co 3 O 4 nanoparticles (Co 3 O 4 –NC NPs) were synthesized using a scalable hydrothermal method and subsequent annealing process; (ii) a dual-ion (Zn 2+ /Mn 2+ )-optimized hybrid electrolyte system, that is, the dual-ion synergy from Mn 2+ additive enhanced Zn 2+ desolvation kinetics while suppressing dendrite formation; and (iii) 3D printing hierarchically porous microlattice architecture integrating reduced graphene oxide/carbon nanotubes-based (rGO/CNTs-based) to establish bicontinuous ion/electron transport networks. The 3DP button Zn–Co cells (thickness: 0.8 mm) delivered an exceptional areal capacity (∼0.30 mAh cm –2 at 2 mA cm –2 ) and excellent cycling stability (near-zero decay over 750 cycles). Specially, a 4 mm thick 3DP flexible quasi-solid-state Zn–Co battery (3DP f-QSS Zn–Co) device employing PVA/(ZnSO 4 + MnSO 4 ) gel electrolyte achieved an enhanced areal capacity (∼0.16 mAh cm –2 at 1 mA cm –2 ), a high energy density (∼151.0 Wh kg –1 at a power of 975 W kg –1 ), and an ultralong cyclability (∼87.5% retention after 2500 cycles at 1 A g –1 ). Furthermore, the 3DP f-QSS Zn–Co devices enabled scalable voltage output through a series integration, successfully powering high-power LEDs and miniature motors. This work introduced an MOF-derived hierarchical porous architecture synergistically integrated with advanced 3D printing, enabling the development of high-performance 3DP-f-QSS Zn–Co batteries specifically engineered for next-generation wearable electronic systems.