Magnetic Supercapacitors-Particle Morphology Have Significant Impact on the Electrochemical Performance

Abstract

Morphology tuning of the electrode material is a promising approach to improve the overall performance of the supercapacitor. To date, there is no strategy that shows that magnetic-field-dependent supercapacitive behavior can also be tuned by changing the morphology. In this work, using various morphologies of a negative electrode material α-Fe2O3 viz., rod, porous rods, solid spheres (SS), and hollow spheres (HS), the effect of morphology on magnetic supercapacitors is unequivocally established. A theoretical model is also proposed to correlate the electrochemical response with the diffusion behavior of electrolyte ions. Under the application of the 200 Gauss magnetic field, an increment of 55% in the specific capacitance is obtained. The change under magnetic field is correlated with changing surface states. This is proven by corresponding electrocatalysis (HER and OER) performance under magnetic field.