The effect of an external magnetic field on the electrochemical capacitance of nanoporous nickel for energy storage

Abstract

This work investigates the effect of a magnetic field on the electrochemical performance of nanoporous nickel (np-Ni). We first compare the electrochemical capacitance of np-Ni electrodes, which were prepared using the chemical dealloying strategy under different magnetic flux densities (B = 0, 500 mT). Our experimental data show that np-Ni500 prepared under an external magnetic field of 500 mT exhibits a much better electrochemical performance, in comparison with that (np-Ni0) prepared without applying a magnetic field. Furthermore, the specific capacitance of the np-Ni0 electrode could be further enhanced when we increase the magnetic flux densities from 0 T to 500 mT, whereas the np-Ni500 electrode exhibits a stable electrochemical performance under different magnetic flux densities (B = 0 mT, 300 mT, 500 mT). This could be attributed to the change in the electrochemical impedance of the np-Ni0 electrode induced by an external magnetic field. Our work thus offers an alternative method to enhance the electrochemical energy storage of materials.