Elucidating Surface Adsorption of Lithium Ions on Electrode Materials Using ⁷Li Dark-State Exchange Saturation...

Area of Science:

• Materials Science
• Electrochemistry
• Physical Chemistry

Background:

• Interfacial chemistry is crucial for advanced Li-ion electrode materials.
• Designing effective surface treatments for solid electrolyte interphases is challenging due to difficulties in measuring ion transfer.
• Understanding Li-ion surface adsorption is key to optimizing battery performance.

Purpose of the Study:

• To introduce 7Li Dark-State Exchange Saturation Transfer (DEST) NMR as a method for directly measuring Li-ion surface adsorption.
• To enable quantitative analysis of interfacial ion transfer properties in electrode materials.
• To facilitate the rational design of beneficial solid electrolyte interphases.

Main Methods:

• Utilized 7Li Dark-State Exchange Saturation Transfer (DEST) NMR spectroscopy.
• Developed an optimized model system with monodisperse submicron particles.
• Employed numerical simulations based on Bloch-McConnell equations for quantitative analysis.

Main Results:

• Demonstrated direct measurement of the Li-ion surface adsorption process at the solid-liquid interface.
• Enabled comparison of Li-ion affinity for different surface functionalities on electrode coatings.
• Quantitatively analyzed surface exchange rates and binding properties.

Conclusions:

• DEST NMR is a valuable tool for probing interfacial ion transfer in Li-ion electrode materials.
• The study provides a method to elucidate the structure-function relationship in electrode coatings.
• This technique aids in the development of next-generation high-energy Li-ion batteries.