Template-determined microstructure and electrochemical performances of Li-rich layered metal oxide cathode

This report unravels the dependence of the microstructure and electrochemical performances of Li-rich layered transition metal oxide (LLMO) on the molecular structure of polymer templates for the formation of oxalate precursor. A representative LLMO, Li1.2Mn0.54Ni0.13Co0.13, is synthesized by co-precipitation method, and three samples, LLMO-PVP, LLMO-PEG and LLMO-PVA, are obtained with polymer templates, polyvinyl pyrrolidone (PVP), polyethyleneglycol (PEG) and polyvinyl alcohol (PVA), respectively. The physical and chemical properties of the resulting products are analyzed with SEM, TEM, XRD, BET, ICP, and XPS, and their electrochemical performances as cathode of Li-ion battery are evaluated with EIS, GITT and charge/discharge tests. It is found that LLMO-PVP exhibits the best performances, followed by LLMO-PEG, while LLMO-PVA behaves poorest. This difference is ascribed to the various microstructures of the resulting products, which are determined by the molecular structure of polymer templates.