Investigation of Solid Electrolyte Interphase Formed on Si Nanoparticle Composite Electrodes Using Hyperpolarized ¹²⁹Xe Nuclear Magnetic Resonance Spectroscopy

Journal Article · Mon Apr 03 00:00:00 EDT 2017 · Energy and Fuels

DOI:https://doi.org/10.1021/acs.energyfuels.7b00250· OSTI ID:1534483

Mao, Yougang ^[1]; Karan, Naba K. ^[2]; Song, Myeonghun ^[2]; Hopson, Russell ^[2]; Guduru, Pradeep R. ^[2]; Wang, Li-Qiong ^[2]

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1. Brown Univ., Providence, RI (United States); DOE/OSTI
2. Brown Univ., Providence, RI (United States)

Solid electrolyte interphase (SEI) plays an important role in determining electrochemical performances of Li-ion batteries. The ideal SEI layer protects the electrolyte from being further reduced on the electrode surface and allows Li-ion diffusion in and out of electrodes without any consumption. However, degradation of the SEI layer over time, which contributes to the thickening of the SEI layer, is a leading pathway for gradual capacity fade. In this study, a hyperpolarized (HP) ¹²⁹Xe nuclear magnetic resonance (NMR) technique was applied for the first time to probe changes in porosity and connectivity in Si nanoparticle composite electrodes as a result of the SEI formation. Nanopores are present in nanocomposite electrodes as a result of aggregation of the constituting nanoparticles. The connectivity among nanopores greatly affects the ion transport property of the electrode materials, which has a substantial influence on the overall energy output of Li-ion batteries. Here, information on thickness, uniformity of the SEI layer, and connectivity of the pores in the composite electrodes upon growing SEI was obtained from the analysis of temperature-dependent HP ¹²⁹Xe NMR spectra. Such information is useful for gaining a better understanding of the degradation mechanism of SEI. This study demonstrates that HP ¹²⁹Xe NMR is a potentially unique tool in probing the porosity and connectivity changes in porous practical electrodes during electrochemical cycling.

• Research Organization: Brown Univ., Providence, RI (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: SC0007074
• OSTI ID: 1534483
• Journal Information: Energy and Fuels, Journal Name: Energy and Fuels Journal Issue: 5 Vol. 31; ISSN 0887-0624
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
electrodes
energy & fuels
engineering
layers
nanoparticles
semiconducting nanostructured materials
surface chemistry