Sensitive Detection of Dendritic Lithium Morphologies by Dynamic Nuclear Polarization

Area of Science:

• Materials Science
• Electrochemistry
• Spectroscopy

Background:

• Lithium metal batteries offer high energy density but face challenges with lithium dendrite formation.
• Nonuniform lithium deposition compromises battery lifetime and safety, necessitating effective detection methods.

Purpose of the Study:

• To demonstrate Overhauser dynamic nuclear polarization (DNP)-enhanced NMR as a sensitive tool for characterizing lithium morphology.
• To correlate DNP enhancement with specific lithium deposition structures, including dendrites.

Main Methods:

• Utilized DNP-enhanced NMR spectroscopy to increase the sensitivity of lithium NMR.
• Systematically controlled lithium deposition within a polymer electrolyte system.
• Employed electron paramagnetic resonance and electron microscopy for complementary analysis.

Main Results:

• DNP enhancement was found to correlate directly with lithium morphology.
• The method successfully distinguished between micro- and nano-sized lithium dendrites.
• Spectroscopic and microscopic data confirmed the morphological interpretations.

Conclusions:

• DNP-enhanced NMR provides a powerful spectroscopic strategy for probing lithium dendritic structures.
• This technique offers high specificity for understanding and controlling dendrite formation in batteries.
• The findings pave the way for improved lithium metal anode development and battery safety.