Tailoring electronic structure and size of ultrastable M‐MOFs (M = Co, Ni) with enhanced electroconductivity for high‐performance supercapacitor

Metal-organic frameworks (MOFs) utilized as electrodes for energy storage/conversion has been a challenge due to their incompetent chemical stability and poor electrical conductivity in electrolyte. Here, a nanoscale MOF, Co 0.24 Ni 0.76 -bpa-200 , possessing ultrahigh stability with uncommon semiconductor behavior (σ = 4.2 × 10 -3 S m -1 ) was fabricated by a combination of robust hydrophobic paddlewheel, optimized Co/Ni ratio, MOF size and conjugated degree of coligand. DFT study reveals that the appropriate Ni 2+ doping reduces the activation energy of system and thus yields a higher carrier concentration, and the strongly delocalized N-donor ligand notably increases the metal-ligand orbital overlap to achieve efficient charge migration, leading to continuous through-bond (-CoNi-N-CoNi-) ∞ conduction paths. The structural features endow the MOF with a good cycling stability of 86.5% (10000 cycles) and a high specific capacitance of 1927.14 F g -1 among pristine MOF-based electrodes.