The main advantage of magnesium battery is its very large theoretical capacities. Owing to the divalent nature of Mg2+ ions, it has substantially higher volumetric and gravimetric capacities. (3833 mAh cm-3 and 2205mAh g-1 respectively). Mg batteries does not experience the irreversible capacity loss due to the solid electrolyte interphase (SEI) formation that usually occurs in many battery systems including Li and Na. In addition, Mg has better stability in the ambient environment hence the battery packaging does not require any inert atmosphere. Mg metal also lack dendrite formation and associated battery failure due to internal short circuit. The main challenge of Mg battery research is the development of compatible cathode material. Unlike the Li+ ion, the Mg2+ divalent ion is more electropositive. Since the ionic radii of both the ions are more or less same (Li+ – 0.76Å, Mg2+ – 0.72Å) the effective charge density of Mg ion is even higher. Hence, Mg2+ ion exhibit more effective columbic interaction with the cathode materials. This interaction kinetically sluggish Mg-ion intercalation to the cathode lattice, and causes low energy/ power density.

In order to overcome the energy density and power density limitations of Mg batteries, we have designed and synthesized nanostructured metal oxide cathodes. Mg-ion storage in this case follows a pseudocapacitive mechanism. Diffusion independent nature of pseudocapacitive mechanism enables ultrafast charging (high power density) of the Mg battery.