3D-Printed Hierarchically Porous MOF-Derived Cathodes for Realizing High-Performance Flexible Quasi-Solid-State Aqueous Zinc–Cobalt Batteries
Ningning Chu, Tenghui Wang, Zhengyang Guo, Xueliang Li, Hui Wang, Tingting Xu, Jinhao Zang, Ye Wang, Xinjian Li, Yongsong Luo, Hui Ying Yang, Dezhi Kong
Abstract
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.