About this Research Topic
With the increasing demands for eco- and renewable energy, the development of low-cost and efficient energy conversion and storage technologies have drawn extensive research attention. Profiting from the high theoretical energy output, low manufacture cost, environmental benignity, and satisfactory safety, metal-air batteries have shown the potential as one of the most promising future power sources since its commercialization in 1930s. However, the development of electrochemically rechargeable metal-air batteries still faces a series of scientific challenges. One of the most key challenges is lack of efficient air-cathodes owing to the inherent sluggish kinetics of oxygen reduction reaction (ORR) during discharge and oxygen-evolution reaction (OER) during recharge. Therefore, it is necessary to develop an effective bifunctional catalyst that can facilitate both ORR and OER.
Even though platinum (Pt) and iridium/ruthenium (Ir/Ru) based materials have been acknowledged as brilliant electrocatalysts for the ORR and OER, respectively, their scarcity, high-cost and poor stability have hampered they from large-scale applications. Therefore, it is greatly important and highly desirable to develop high-performance and cost-effective alternatives of conventional noble-metals as bifunctional catalysts for both ORR and OER. Alternative materials based on non-noble metals have been intensively explored as the cost-effective bifunctional oxygen catalysts, comprising carbon-based materials, transition-metal oxides/sulfides/hydroxides and their hybrids. Among all the available alternatives, the carbon-based catalysts are the most investigated ones owing to low-cost, excellent electrical conductivity and attractive synergetic effects between carbon and other components. Despite this there has been promising progress, several major challenges are still present in the development of desired carbon-based bifunctional catalysts: (i) The adsorption-desorption behaviors of oxygen species and the accurate reaction mechanism of OER on carbon surface are not clear; (ii) carbon-based materials generally are electrochemically unstable under the harsh OER condition with the unavoidable carbon corrosion. (iii) The precise control of carbon micro/nanostructure for exposing more catalytically active-sites and obtaining high specific-surface-area still needs more investigation. Therefore, there is still a long way in applying these promising carbon-based materials to the practical Zn-air batteries, for which important breakthroughs are highly expected.
We welcome the submission of full research papers, reviews and perspectives on themes which may include, but are not limited to:
• Novel design of carbon-based materials for the ORR and/or OER.
• Optimization of structure and composition of carbon-based oxygen electrocatalysts.
• New understanding of electrocatalytic mechanism of carbon-based electrocatalysts for the ORR/OER based on theoretical and experimental approaches.
• The potential application of carbon-based materials in metal-air batteries.
• Theoretical work on carbon-based materials for oxygen electrocatalysis.
Keywords: Electrocatalysts, Carbon-Based materials, Oxygen reduction reaction, Oxygen-evolution reaction, Metal-air batteries
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