Engineering Nanoporous and Active Channels of Heterostructured COF@MOF‐Ti 3 C 2 T x Toward High‐Performance 3D Printed Micro‐Supercapacitors

ABSTRACT 3D printed micro‐supercapacitors have attracted unprecedented attention in the fields of wearable electronics and Internet of Things devices. However, the conventional electrode materials generally suffer from limited porous structure and insufficient active sites, resulting in low specific capacitance and restricted practical application. In this work, we report a 3D printed micro‐supercapacitor based on a heterostructured COF@MOF‐Ti 3 C 2 T x electrode material, which features an engineered nanoporous structure and high electrochemical activity. Due to the precise control of hierarchical nanopores and active cobalt and nickel metal sites, enhanced redox activity, the COF@MOF‐Ti 3 C 2 T x electrode material has fast ion diffusion kinetics, high ion adsorption energy, excellent electron conductivity, and large pseudocapacitive reversibility. As a result, COF@MOF‐Ti 3 C 2 T x achieves a high capacitance of 1078.0 F g −1 , a lower ionic diffusion impedance and structural stability. Furthermore, the assembled solid‐state micro‐supercapacitor exhibits an energy density of 60.3 µWh cm −2 and cyclic stability for successfully powering intelligent traffic signals and alarm clocks, which provides a new approach for the development of high‐performance and customizable micro‐energy storage systems.