Supercapacitor development from transition metal-integrated spinel manganese oxide-carbon nanotubes composite materials

Abstract

Supercapacitors are electrochemical energy storage devices, much like Li-ion batteries, that have expeditiously been improved over the years through extensive research conducted in material sciences and nanotechnology. Since supercapacitors are mostly known for their high power densities and extended lifecycle, they are therefore mainly employed in applications where large quantities of energy is required to be stored and/or released within quick time periods and energy outputs. In the modern technological era, supercapacitors are predominantly employed in hybrid electric vehicles (HEVs), trains, trams, cranes, cell phones, as uninterrupted power supplies (UPS devices), and in memory backup units for computer systems. Apart from these conventional application areas, the application field of energy storage that ultimately makes supercapacitors blossom, is the field of storing harvested renewable energy from self-sustaining power sources such as solar cells and/or wind turbines. However, the unfortunate disadvantage associated with supercapacitors is its low energy density compared to batteries. Therefore, this research work presents the study of multi-walled carbon nanotubes (MWCNTs) integrated with spinel nanostructured CuMn2O4 nanoparticles as composite electrode materials towards enhancing the energy performance in asymmetric pseudocapacitors. The hybrid composite (CuMn2O4/MWCNT) development process initially started with the synthesis of the pristine (hausmannite-type) Mn3O4 material, upon modification thereafter with copper and carbon nanoparticles.