Radiation‐Induced in Situ Construction of 2D Conductive Defect‐Rich Metal‐Organic Frameworks for High‐Performance Supercapacitor
Kai Zhang, Xuanzhi Mao, Yan Wei, Chunyang Li, Linwei He, Yiwen Long, Maosheng Wu, Chao-Wei Luo, Hong‐Yan Zeng, Mingxing Zhang, Guozhong Wu
Abstract
Abstract 2D conductive metal‐organic frameworks (2D c‐MOFs), featuring ordered 1D pore channels, extended 2D π‐conjugated layered structures, and reversible redox‐active sites, are identified as promising electrode materials for high‐performance supercapacitors (SCs). Herein, a representative Cu‐based 2D c‐MOF (Cu‐CAT) is synthesized for the first time through gamma ray radiation. The resulting Cu‐CAT exhibited abundant defective structures and a higher proportion of low‐valence Cu metal centers, attributed to in situ radiation‐induced etching and reduction, while maintaining decent crystallinity and porosity. Interestingly, beneficial to the increased active sites resulting from the defects, the as‐synthesized Cu‐CAT electrode demonstrated remarkable capacitive performance in aqueous electrolytes (3.0 m KCl solution), achieving a specific capacitance of up to 508 F g −1 at a current density of 0.2 A g −1 , surpassing that Cu‐CAT synthesized via the conventional solvothermal processes (285 F g −1 at 0.2 A g −1 ) and most reported 2D c‐MOFs. Furthermore, a symmetric two‐electrode button cell fabricated using the as‐synthesized Cu‐CAT exhibited a high gravimetric capacitance of 365 F g −1 at 0.5 A g −1 , a notable energy density of 50.72 W h kg −1 at a power density of 0.25 kW kg −1 , and excellent cycling stability, retaining ≈91.6% of its initial capacitance after 10,000 cycles.