Theoretical insights into electron transport properties of solid electrolyte interphase and electrocatalysts design for renewable energy utilizations

Abstract

Advancements in high-performance rechargeable batteries and electrocatalysts are crucial for harnessing renewable energy sources. In rechargeable batteries, the solid-electrolyte interphase (SEI) is a complex and vital component, partly due to its electron transport properties. When designing electrocatalysts, theoretical screening and mechanistic analysis are essential tools that can aid in developing efficient electrocatalysts for a range of reactions, such as the oxygen reduction reaction (ORR), the oxygen evolution reaction (OER), and the electrochemical reduction of nitrate to ammonia (NO3RR). Despite the inevitable presence of heterogeneous interfaces between different solid inorganic components within the SEI, the electron transport properties of these interfaces have not been investigated either experimentally or theoretically. This study utilized the non-equilibrium Green’s function method to theoretically assess the electron transport properties under bias voltage for interfaces between LiF and Li2O, as well as individual layers of these two components, given their common stability within the SEI. This work revealed the contrasting effects of heterogeneous SEI interfaces orthogonal and parallel to the external electric field direction, and predicted the critical thickness of single-crystal LiF and Li2O. Dual-atom catalysts (DACs) show promise in the ORR and the OER. However, studies on DACs often overlook crucial factors such as curvature effects and dissociative mechanisms, potentially leading to missed opportunities in identifying optimal candidates. To enhance our understanding of how these factors influence effective electrocatalyst design, this study systematically investigated the catalytic potential of MM′N6-DACs supported on graphene and single-walled carbon nanotubes with varying diameters, exploring both dissociative and associative mechanisms. The study identifies more than ten DACs that exhibit high activity, surpassing common commercial catalysts with significantly lower overpotentials. The dissociative mechanism, which overcomes scaling relationship constraints in the associative mechanism, leads to improved activity in several DACs, achieving lower overpotentials than the theoretical minimum of the associative mechanism. The NO3RR holds promise for addressing environmental nitrate-related issues and facilitating ammonia production at ambient temperatures. However, significant challenges exist, including the lack of effective electrocatalysts and a comprehensive understanding of the underlying reaction mechanisms. To address these challenges, we conducted first-principles calculations to investigate the performance and mechanisms of triple-atom catalysts (TACs) comprising transition metals anchored on N-doped carbon. The study identified six promising candidates exhibiting both thermodynamic and electrochemical stability, as well as high activity and selectivity for ammonia synthesis. These promising candidates benefit from overcoming the constraints of the scaling relationship, a well-known limitation for single-atom catalysts. The results of this study offer significant insights into the comprehension of electron transport properties within rechargeable batteries and the reaction mechanisms of the three examined reactions. These findings have the potential to enhance the performance of associated batteries and electrocatalysts.