Nanostructured Europium and Palladium Oxide Substituted Lithium Manganese Oxide [LiEu(x)PdO(y)MnO3] Perovskite Material for Li Ion Battery Cathode

Abstract

The 4th Industrial revolution which is to be mainly powered by cleaner energy technologies has necessitated the scientific community to develop new high-tech energy storage materials. Furthermore, 4IR is associated with increased use of handheld and portable devices which require energy carriers such as supercapacitors and batteries with high power densities and high capacities. Although layered materials such as highly lithiated manganese oxides have paved the way in the development of new high-tech energy storage materials for Li-ion batteries, there is still huge room for improvements in such materials to achieve even greater electrochemical performance. It has been reported that highly lithiated manganese oxides can be modified using a variety of methods, such as surface coating, doping, and acid treatment to improve their stability and general electrochemical performance. Thus, this research focused on integrating these modification strategies to develop electrochemical superior highly lithiated manganese oxides to be applied as aqueous based Li-ion battery cathodes. In this work, europium doped highly lithiated manganese oxide Li2MnO3 were synthesized through sol-gel synthesis and electrochemically evaluated. The synthesized europium doped Li2MnO3 were then treated with mild HNO3 as acid treatment, which has a synergistic effect on its electrochemical performance. Lastly, A jointly modified highly lithiated manganese oxide Li2MnO3 was fabricated by doping with europium and then decorating its surface with PdO via sonochemical methods to form a corrosion protective layer. The produced materials were characterized by Powder X-ray Diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FTIR), Small Angle X-ray Scattering (SAXS), Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), High Resolution Scanning Electron Microscopy (HR-SEM), High Resolution Transmission Electron Microscopy (HR-TEM), and their electrochemical properties were evaluated using Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) and Galvanostatic Charge Discharge (GCD) in 1 M Li2SO4 electrolyte solution. The synthesized materials Li2Mn0.95Eu0.05O3, Acid treated Li2Mn0.95Eu0.05O3, and PdO@Li2Mn0.95Eu0.05O3 exhibited good electrochemical properties and yielded discharge capacities of 4.20, 17.8 and 6.4 mAh.g-1 respectively.