Surface Sensitive NMR Detection of the SEI Layer on Reduced Graphene Oxide

Autor: Leskes, Michal, Kim, Gunwoo, Liu, Tao, Michan, Alison L, Aussenac, Fabien, Dorffer, Patrick, Paul, Subhradip, Grey, Clare P
Přispěvatelé: Kim, Gunwoo [0000-0001-9153-3141], Grey, Clare [0000-0001-5572-192X], Apollo - University of Cambridge Repository
Rok vydání: 2019
Předmět:
DOI: 10.17863/cam.35142
Popis: The solid electrolyte interphase (SEI) is detrimental for rechargeable batteries performance and lifetime. Understanding its formation requires analytical techniques that provide molecular level insight. Here dynamic nuclear polarization (DNP) is utilized for the first time for enhancing the sensitivity of solid state NMR (ssNMR) spectroscopy to the SEI. The approach is demonstrated on reduced-graphene oxide (rGO) cycled in Li-ion cells in natural abundance and 13C-enriched electrolyte solvents. Our results indicate that DNP enhances the signal of outer SEI layers, enabling detection of natural abundance 13C spectra from this component of the SEI at reasonable timeframes. Furthermore, 13C- enriched electrolytes measurements at 100K provide ample sensitivity without DNP due to the vast amount of SEI filling the rGO pores, thereby allowing differentiating the inner and outer SEI layers composition. Developing this approach further will benefit the study of many electrode materials, equipping ssNMR with the needed sensitivity to efficiently probe the SEI.
The work was supported by a research grant from Dana and Yossie Hollander, the Alon fellowship from Israel council of higher education and partially by the Israel Science Foundation (ISF) in the framework of the INREP project (M.L.). This project has received funding from the European Unions’s Horizon 2020 research and innovation programme under Grant Agreement No. 696656 – GrapheneCore1 (G.K. and C.P.G.). We thank Dr. Wanjing Yu (Central South University, China) for graphene synthesis and related discussions. G.K. thanks Dr. Duhee Yoon (Cambridge Graphene Centre) for Raman measurements and helpful discussions. The research is made possible in part by the historic generosity of the Harold Perlman family. We thank Dr. Frederic Mentink-Vigier for helpful suggestions. DNP experiments at 14.1 T were performed at the DNP MAS NMR Facility at the University of Nottingham, with thanks to the EPSRC for funding of pilot studies (EP/L022524/1).
Databáze: OpenAIRE