Cauliflower‐Like Nickel‐Based Bilinker Metal–Organic Frameworks for High‐Performance Hybrid Supercapacitors

Nickel‐based metal–organic frameworks (Ni‐MOFs) have emerged as promising electrode materials for hybrid supercapacitors, owing to their intrinsic redox activity, adjustable porosity, and high density of electroactive sites. Despite these advantages, achieving both high specific capacitance and prolonged electrochemical stability remains a significant challenge. In the present work, we report the synthesis of a novel bilinker Ni‐MOF featuring a distinctive cauliflower‐like morphology, constructed using benzene‐1,4‐dicarboxylic acid (BDC) and gallic acid as organic linkers. To the best of our knowledge, this is the first instance where this particular linker combination has been employed for supercapacitor applications. Electrochemical evaluations conducted in 2 M KOH electrolyte revealed an impressive specific capacitance of 510 F g −1 at a current density of 0.5 A g −1 . Additionally, a hybrid supercapacitor (HS) was fabricated, exhibiting a power density of 4000 W kg −1 and an energy density of 8.33 W h kg −1 . Remarkably, the device retained 96% of its initial capacitance after 5000 continuous charge–discharge cycles, highlighting its excellent cycling stability. These findings demonstrate the potential of bilinker Ni‐MOF architectures in the development of high‐performance HSs.