Tailoring Pore Structures of 3D Printed Cellular High-Loading Cathodes for Advanced Rechargeable Zinc-Ion Batteries.

Developing high-loading cathodes with superior electrochemical performance is desirable but challenging in aqueous zinc-ion batteries (ZIBs) for commercialization. Advanced 3D printing of cellular and hierarchical porous cathodes with high mass loading for superior ZIBs is explored here. To obtain a high-performance 3D printable ink, a composite material of iron vanadate and reduced holey graphene oxide is synthesized as the ink component. A cellular cathode with hierarchical porous architecture for aqueous ZIBs is then designed and fabricated by 3D printing for the first time. The unique structures of 3D printed composite cathode provide interpenetrating transmission paths as well as channels for electrons and ions. 3D printed cathodes with high mass loading over 10 mg cm-2 exhibit a high specific capacity of 344.8 mAh g-1 at 0.1 A g-1 and deliver outstanding cycling stability over 650 cycles at 2 A g-1 . In addition, the printing strategy enables the ease increase in mass loading up to 24.4 mg cm-2 , where a remarkably high areal capacity of 7.04 mAh cm-2 is reached. The superior electrochemical performance paves the new way to design the state-of-the-art cathodes for ZIBs.