Depletion of fossil fuels and detrimental effect of current energy sources on environment forced us to search for alternative energy generation or storage and conversion technology for the upcoming energy crisis. Among various energy conversion and storage devices such as lithium-ion batteries and supercapacitors, lithium-air (Li-air) batteries are the most promising candidate that can compete with gasoline according to Ragone plot up to now. Even though being the best choice for vehicles electrification, developing the catalysts which is used for reducing oxygen coming from the air is still biggest limitation for this type of battery. Cerium dioxide (CeO2) is a very versatile material due to its excellent redox property providing ability to shift Ce4+ to Ce3+ resulting a change in oxidation states and oxygen vacancy defects by very small activation energy. In additions, the catalytic property of ceria is directly related to its oxygen storage capacity which means the number of oxygen vacancies that structure can host. The oxygen vacancies can be mostly abundant in nanorods form and it leads the improvement of highly efficient catalysts properties without the change of the catalyst composition. On the other hand, carbon materials have excellent electrical conductivity, high specific surface area and chemical stability. In this study, nitrogen doped reduced graphene oxide (NrGO) was synthesized by thermal annealing method processing graphene oxide at elevated temperature in ammonia and argon gas ambient. Then, CeO2 nanorods decorated NrGO were successfully synthesized by a simple hydrothermal process to use an efficient catalyst material on a conductive support as an electrode material for Li-air. The structural and morphological analyses all sample were performed by XRD, SEM, BET analysis and RAMAN spectroscopy to investigate and optimize the incorporation of nanorods with the NrGO support. 3D Li-air electrodes were prepared by using nickel foam which was coated by a slurry containing CeO2/NrGO as active material, carbon black as conductive agent and PvDF as binder. Electrochemical analysis such as CV and charge-discharge tests were operated by using a special battery cell allowing oxygen gas inside. The result showed that CeO2/NrGO remain stable and save their energy capacities in high current values due to the enhanced Li+ ion and electron mobility. It is found that the results are promising for high power and high capacity Li-air battery applications.

Cerium dioxide catalyst nanorods decorated three-dimensional nitrogen doped and reduced graphene oxide electrodes for Li-air batteries

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.