Single Atom Catalysts for Fuel Cells and Rechargeable Batteries: Principles, Advances, and Opportunities

Abstract

Owing to the energy crisis and environmental pollution, developing efficient and robust electrochemical energy storage (or conversion) systems is urgently needed but still very challenging. Next-generation electrochemical energy storage and conversion devices, mainly including fuel cells, metal-air batteries, metal-sulfur batteries, and metal-ion batteries, have been viewed as promising candidates for future large-scale energy applications. All these systems are operated through one type of chemical conversion mechanism, which is currently limited by poor reaction kinetics. Single atom catalysts (SACs) perform maximum atom efficiency and well-defined active sites. They have been employed as electrode components to enhance the redox kinetics and adjust the interactions at the reaction interface, boosting device performance. In this Review, we briefly summarize the related background knowledge, motivation and working principle toward nextgeneration electrochemical energy storage (or conversion) devices, including fuel cells, Zn-air batteries, Al-air batteries, Li-air batteries, Li-CO 2 batteries, Li-S batteries, and Na-S batteries. While pointing out the remaining challenges in each system, we clarify the importance of SACs to solve these development bottlenecks. Then, we further explore the working principle and current progress of SACs in various device systems. Finally, future opportunities and perspectives of SACs in next-generation electrochemical energy storage and conversion devices are discussed.

Universal‐Descriptors‐Guided Design of Single Atom Catalysts toward Oxidation of Li2S in Lithium–Sulfur Batteries

“…Therefore, the design of SACs for Li–S batteries relies solely on the conventional trial‐and‐error method. Given numerous degrees of freedom for adjusting the local atomic environments, the catalytic properties of SACs can be tuned accordingly in a wide range, [ 29 , 30 ] which necessitate more advanced and efficient design strategy. High throughput calculations have been widely implemented to search for high efficiency SACs for various electrochemical reactions such as oxygen reduction reaction (ORR), oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and N 2 reduction reaction (NRR).…”

Ionic Covalent Organic Frameworks for Energy Devices

“…Thus, the design of highly conductive and stable membrane materials that can outperform Nafion will boost the development of fuel cell technologies. [ 172,198–200 ]…”

Active site engineering of single-atom carbonaceous electrocatalysts for the oxygen reduction reaction

“… 80 The distinguished ORR activity of such M–N–C materials empowered the as-assembled metal–air batteries with superior performance. 81 Unfortunately, in an acidic electrolyte, the electrocatalytic activities of such M–N–C materials are still much lower than those of PGM-based components, 82 motivating the further rational engineering of the active site at the atomic level.…”