@article{3994ad4e96574533a736302fc2723944,
title = "Atomic Structure Modification of Fe‒N‒C Catalysts via Morphology Engineering of Graphene for Enhanced Conversion Kinetics of Lithium–Sulfur Batteries",
abstract = "Single-atom M‒N‒C catalysts have attracted tremendous attention for their application to electrocatalysis. Nitrogen-coordinated mononuclear metal moieties (MNx moities) are bio-inspired active sites that are analogous to various metal-porphyrin cofactors. Given that the functions of metal-porphyrin cofactors are highly dependent on the local coordination environments around the mononuclear active site, engineering MNx active sites in heterogeneous M‒N‒C catalysts would provide an additional degree of freedom for boosting their electrocatalytic activity. This work presents a local coordination structure modification of FeN4 moieties via morphological engineering of graphene support. Introducing highly wrinkled structure in graphene matrix induces nonplanar distortion of FeN4 moieties, resulting in the modification of electronic structure of mononuclear Fe. Electrochemical analysis combined with first-principles calculations reveal that enhanced electrocatalytic lithium polysulfide conversion, especially the Li2S redox step, is attributed to the local structure modified FeN4 active sites, while increased specific surface area also contributes to improved performance at low C-rates. Owing to the synergistic combination of atomic-level modified FeN4 active sites and morphological advantage of graphene support, Fe‒N‒C catalysts with wrinkled graphene morphology show superior lithium–sulfur battery performance at both low and high C-rates (particularly 915.9 mAh g−1 at 5 C) with promising cycling stability.",
keywords = "M‒N‒C catalysts, electrocatalysis, lithium–sulfur batteries, local coordination environment engineering, single-atom catalysts",
author = "Jiheon Kim and Kim, {Seong Jun} and Euiyeon Jung and Mok, {Dong Hyeon} and Paidi, {Vinod K.} and Jaewoo Lee and Lee, {Hyeon Seok} and Yunseo Jeoun and Wonjae Ko and Heejong Shin and Lee, {Byoung Hoon} and Kim, {Shin Yeong} and Hyunjoong Kim and Kim, {Ji Hwan} and Cho, {Sung Pyo} and Lee, {Kug Seung} and Seoin Back and Yu, {Seung Ho} and Sung, {Yung Eun} and Taeghwan Hyeon",
note = "Funding Information: J.K., S.‐J.K., and E.J. contributed equally to this work. T.H. acknowledges the financial support by the Institute for Basic Science (IBS‐R006‐D1) and Y.‐E.S. acknowledges the financial support by the Institute for Basic Science (IBS‐R006‐A2). S.‐H.Y. acknowledges the support of the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT) (NRF‐2020R1C1C1012308). S.B. acknowledges the support from the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (no. 2015M3D3A1A01064929) and generous supercomputing time from KISTI (KSC‐2020‐CRE‐0116). X‐ray absorption spectroscopy analysis at the Pohang Accelerator Laboratory (PAL) 8C beamline was also supported by NRF (no. 2019M3D1A1079309). The authors thank the National Center for Inter‐University Research Facilities (NCIRF) at Seoul National University for ICP‐AES and AC‐HAADF‐STEM measurement. The authors also appreciate Busan center of the Korea Basic Science Institute (KBSi) for X‐ray photoelectron spectroscopy analysis. Funding Information: J.K., S.-J.K., and E.J. contributed equally to this work. T.H. acknowledges the financial support by the Institute for Basic Science (IBS-R006-D1) and Y.-E.S. acknowledges the financial support by the Institute for Basic Science (IBS-R006-A2). S.-H.Y. acknowledges the support of the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT) (NRF-2020R1C1C1012308). S.B. acknowledges the support from the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (no. 2015M3D3A1A01064929) and generous supercomputing time from KISTI (KSC-2020-CRE-0116). X-ray absorption spectroscopy analysis at the Pohang Accelerator Laboratory (PAL) 8C beamline was also supported by NRF (no. 2019M3D1A1079309). The authors thank the National Center for Inter-University Research Facilities (NCIRF) at Seoul National University for ICP-AES and AC-HAADF-STEM measurement. The authors also appreciate Busan center of the Korea Basic Science Institute (KBSi) for X-ray photoelectron spectroscopy analysis. Publisher Copyright: {\textcopyright} 2022 Wiley-VCH GmbH.",
year = "2022",
month = may,
day = "9",
doi = "10.1002/adfm.202110857",
language = "English",
volume = "32",
journal = "Advanced Functional Materials",
issn = "1616-301X",
publisher = "Wiley-VCH Verlag",
number = "19",
}