Selective Self‐Assembly of Atomically Dispersed Iron and Cobalt Dual Atom Catalyst on Anisotropic Mesoporous Carbon Particles for High Performance Seawater Batteries

• Published in: Advanced functional materials Vol. 35; no. 6
• Main Authors: Woo, Dongyoon, Kim, Jioh, Xu, Liangliang, Park, Jinkyu, Park, Cheol‐Young, Yi, Seung Yeop, Kim, Seongbeen, Jun, Hyunwoo, Kim, Seongseop, Lee, Jinwoo
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.02.2025
• Subjects: Carbon; Catalysts; Catalytic activity; Chemical synthesis; Density functional theory; Distilled water; dual‐atom catalyst; Electrocatalysts; Electrode materials; Electrolytes; Iron; Nonaqueous electrolytes; ordered mesoporous carbon; Oxygen; oxygen electrocatalyst; Polymer blends; Prepolymers; Seawater; seawater battery; selective self‐assembly; Self-assembly; Spinodal decomposition
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202414749

Na‐seawater batteries (SWBs) are environmentally friendly energy storage system that utilizes abundant seawater as an electrolyte alternative to conventional distilled water‐based and organic electrolytes. To achieve high energy efficiency in Na‐SWBs, it is necessary to enhance the activity of bifunctional oxygen electrocatalysts. In this study, an atomically dispersed iron and cobalt dual‐atom nitrogen‐doped lens‐shaped mesoporous carbon (FeCo‐LMC) particles is synthesized as a SWB cathode material using the spinodal decomposition of the polymer blend and selective precursor positioning. The well‐aligned mesoporous structure and synergetic effect of the dual‐atom site realize FeCo‐LMC as a comparable bifunctional oxygen catalyst with the lowest overpotential difference (EOER−EORR) among the other catalysts with natural seawater electrolyte. When applied to the SWB system, the FeCo‐LMC shows a highly improved charge/discharge performance compared to Pt/C and a stable cycling performance for 200 h. Density functional theory calculations reveal the enhanced oxygen catalytic activity of FeCo‐LMC owing to electron delocalization and d‐band center adjustment of FeN4–CoN4 structure. Atomically dispersed Fe and Co dual‐atom nitrogen‐doped lens‐shaped mesoporous carbon (FeCo‐LMC) particles are prepared by the selective self‐assembly of a polymer blend, assisted by hydrophilic/hydrophobic interactions. The well‐aligned ordered mesoporous FeCo‐LMC structure shows an enhanced bifunctional oxygen catalytic performance in seawater. Moreover, FeCo‐LMC exhibits superior activity as a Na‐seawater battery cathode material owing to the optimized electronic structure modification of the dual‐atom sites.