A Non-Ignorable Avenue to Reduction of Leakage Current : The Variational Method Guided Confining Tip Discharge for High-Performance Mof-Derived Supercapacitors

Nanosized electrode materials have received wide attention in electrochemistry since their large specific surface areas are the precondition for the excellent performance of electrochemistry, such as supercapacitors, Li-ion batteries, Na-ion batteries, electrocatalysis, photoelectrocatalysis, electrolysis and electrodeposition. However it also leads to the high value of curvature of nanomaterials, causing the unavoidable and non-ignorable leakage currents, and therefore the activity degradation. Here, guided by the variational method, we first theoretically predict that, with giving a certain value of curvature, the paraboloid structure possesses the maximal surface area to greatly reduce the tip-charge, thus guaranteeing the electrochemical performance. Consequently, with using supercapacitors as the model application, this unusual morphological structure was successfully constructed in the metal-organic frameworks (MOFs)-derived Zn-Ni-Co-P@CoP nanowire arrays (ZNCP@CoP NWRs), which largely ensures an ultralow leakage current of 10.28 μA. The low curvature structure of ZNCP@CoP NWRs also significantly improves the electrochemical performance of supercapacitors with a large specific capacitance of 1483 C g −1 at 1 A g −1 and a high cyclic stability of 80% capacity maintained over 5000 cycles at 5 A g −1 . The finding in this work highlights the great potential of the reasonable material design approach for advanced energy applications