Preparation of Co3O4 Electrodes with Different Morphologies for the Investigation of Magnetic Response in Hybrid Capacitors

Abstract The magnetic response of hybrid capacitors (HCs) has become an essential topic in practical applications and fundamental research, but because of the complicated contact surface between the electrode and electrolyte, identifying the effect of the morphologies of electrodes on the magnetic response remains challenging. Here, we prepared needle‐, weed‐ and net‐like Co 3 O 4 as electrodes to investigate the morphology‐dependent HCs properties under a magnetic field (MF). The results showed that the capacity of the needle‐ and weed‐like electrode changes in a range of 5.8 % to −23.2 % and 12.8 % to −5.1 % at a scan rate from 5 to 100 mV/s with a 4000Gs magnetic field, while that of net‐like electrode changes from 45.3 % to 41.3 %. The different magnetic response is attributed to the effect of the morphology on electrolyte convection under an external magnetic field. This work favours understanding the magnetic dependence of HCs properties and pushes the practical application of HCs in magnetic environments.