Carbon tungsten oxide composite cathode materials for aluminum-ion batteries

Aluminum-ion batteries use more abundant materials and suffer from fewer safety risks than lithium-ion batteries. In this work, new cathode materials for Al-ion batteries were synthesized and tested. WO3, carbon materials, and WO3-carbon composite were prepared by sol-gel and chemical vapor deposition methods. These materials differ in microstructure and other physicochemical properties and the possibility of using them as cathode materials was tested. The correlation between the phase composition, structure, microstructure, electrical properties, and electrochemical performance was described based on X-ray diffraction, scanning electron microscopy, electrochemical impedance spectroscopy, and galvanostatic discharge results. WO3, Norit, and WO3/carbon core-shell composite materials exhibit the smallest average grain size in the range of tens of nanometers while materials based on potato starch carbons contain grains in the range of tens of micrometres. The highest values of the open cell voltage and capacitance of Al-ion cells were found for single-phase WO3 and Norit materials, whereas in the case of single-phase Carbon PS these parameters acquire much lower values.