Magnetic supercapacitors have been seen rapid development over the last few years. It has been shown by our team that electrodes having at least one ferromagnetic element can show significant change in electrochemical performance determined under varying magnetic field environment. This has been mostly attributed to the appearance of Lorentz force and magneto hydrodynamics. Change in particle morphologies of the same material can also lead to change in the performance under magnetic field, which has never been reported. Using α-Fe₂O₃ as a test sample, it is shown that this can also happen and changes can be quite appreciable. Different morphologies viz., microrod (MR), porous microrod (PMR), porous nanorod (PNR) of Fe₂O₃ were used to derive this inference. The specific capacitance increases from 12 F g^-1 (in MR) to 82 F g^-1 (in PNR) at 0 Gauss and from 16 F g^-1 (in MR) to 127 F g^-1 (in PNR) at 200 Gauss. A new theoretical model is proposed, which successfully establishes the modified diffusion behaviour of electrolyte ions and correlates with the changes in the diffusion coefficient to explain the results.