Simple solid-state method for synthesis of Li[Li0.20Mn0.534Ni0.133Co0.133]O2 cathode material with improved electrochemical performance in lithium-ion batteries

Abstract

Layered Li[Li 0.20 Mn 0.534 Ni 0.133 Co 0.133 ]O 2 cathode materials for Li-ion battery were successfully prepared by a novel simple solid-state method using acetate or carbonate as a precursor under high temperature, and were then surfacemodified with nanostructured alumina (Al 2 O 3 ). The prepared cathode materials were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscope (SEM), transmission electron microscope (TEM), and electrochemical measurements. The XRD results show that all the cathode materials possess an α-NaFeO 2 structure type with high crystallinity. SEM and TEM images reveal that the cathode materials have a monodisperse nonspherical morphology and the surface became rough but their morphology did not change very much after Al 2 O 3 coating. XRF test proved the presence of Al 2 O 3 in the samples after coating treatment. The electrochemical measurements exhibit that the Al 2 O 3 -coated cathode materials have a higher capability and cycling performance in lithium-ion battery than that of uncoated samples. Further, electrochemical impedance spectra (EIS) measurement shows that the Al 2 O 3 nanoparticles on the surface of the cathode materials reduced side reactions during cycling electrode/electrolyte interface and provided a balanced electronic and Li-ion conductivity. This promising technology for making high performance electrodes would inspire the design and development of a wide range of other battery-related materials in a more eco-friendly way.

Understanding the Role of Minor Molybdenum Doping in LiNi0.5Co0.2Mn0.3O2 Electrodes: from Structural and Surface Analyses and Theoretical Modeling to Practical Electrochemical Cells

“…There are several approaches to prepare layered lithiated transition metal oxide cathode materials. In all of the commonly used methods, precursors containing the elements in the right stoichiometry are prepared and then the final stage is always calcination at elevated temperatures in the range 700–900 °C (depending on the composition) in air or under a pure oxygen atmosphere, which forms the final ordered layered structure. − …”