Solid State Ionics, Vol.317, 89-96, 2018
A review on advancement in non-noble metal based oxides as bifunctional catalysts for rechargeable non-aqueous Li/air battery
Rechargeable non-aqueous Li/air battery is considered as a better alternative for Li-ion batteries for electric vehicle and large-scale energy storage because of its high theoretical energy density, 11,400 Wh kg(-1), close to that of fossil fuel, gasoline (13,000 Wh kg 1). However, the exorbitant over voltage mainly caused by sluggish Oxygen Reduction Reaction (ORR) and Oxygen Evolution Reaction (OER) impedes the extraction of full potential of Li/air system. Essentially Li/air system needs bifunctional catalyst to enhance the rate of both OER and ORR. The formation of insoluble discharge product, oxides of Li and decomposition of non-aqueous electrolytes complicate the mechanism of ORR/OER and hence finding an effective catalyst for non-aqueous Li/air system is a challenging task. Even the catalytic activity of well-known catalysts for ORR/OER of aqueous system could not be translated to non-aqueous Li/air system. Different kind of materials like noble metals, non-noble metals and their oxides as well as carbon based materials have been investigated for their bifunctional catalytic activity in non-aqueous Li/air system. In this context, this paper presents the overview of advancement in bifunctional low-cost non-noble transition metal oxides based catalysts for non-aqueous Li/air battery.
Keywords:Li/air battery;Bifunctional catalyst;Gas Diffusion Electrode (GDE);Oxygen Reduction Reaction (ORR);Oxygen Evolution Reaction (OER)