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.