Ethanol‐Induced Ni ²⁺ ‐Intercalated Cobalt Organic Frameworks on Vanadium Pentoxide for Synergistically Enhancing the Performance of 3D‐Printed Micro‐Supercapacitors

Abstract The synthesis of metal‐organic framework (MOF) nanocomposites with high energy density and excellent mechanical strength is limited by the degree of lattice matching and crystal surface structure. In this study, dodecahedral ZIF‐67 is synthesized uniformly on vanadium pentoxide nanowires. The influence of the coordination mode on the surface of ZIF‐67 in ethanol is also investigated. Benefitting from the different coordination abilities of Ni ²⁺ , Co ²⁺ , and N atoms, spatially separated surface‐active sites are created through metal‐ion exchange. Furthermore, the incompatibility between the d ⁸ electronic configuration of Ni ²⁺ and the three‐dimensional (3D) structure of ZIF‐67 afforded the synthesis of hollow structures by controlling the amount of Ni doping. The formation of NiCo‐MOF@CoOOH@V ₂ O ₅ nanocomposites is confirmed using X‐ray absorption fine structure analysis. The high performance of the obtained composite is illustrated by fabricating a 3D‐printed micro‐supercapacitor, exhibiting a high area specific capacitance of 585 mF cm ⁻² and energy density of 159.23 µWh cm ⁻² (at power density = 0.34 mW cm ⁻² ). The solvent/coordination tuning strategy demonstrated in this study provides a new direction for the synthesis of high‐performance nanomaterials for electrochemical energy storage applications.