Solid-State Nuclear Magnetic Resonance Studies of Electrochemically Discharged CF(x)

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Previous electrochemical studies identified superior performance in fiber-based carbon monofluoride (CF(x)) compared to petroleum coke-based and graphite-based CF(x).
• Understanding the atomic and molecular structural factors is crucial for optimizing CF(x) materials for electrochemical applications.

Purpose of the Study:

• To investigate the atomic/molecular structural differences in various CF(x) materials.
• To correlate these structural variations with observed electrochemical performance disparities.

Main Methods:

• Utilized Carbon-13 (13C) and Fluorine-19 (19F) Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) spectroscopy.
• Analyzed structural changes in CF(x) materials as a function of electrochemical discharge.

Main Results:

• Identified quantitative variations in covalent carbon-fluorine (CF) bonds and lithium fluoride (LiF) species.
• Detected the presence of sp(3) hybridized carbon atoms in discharged fiber-based CF(x).

Conclusions:

• The superior electrochemical performance of fiber-based CF(x) is linked to its distinct atomic/molecular structure.
• Specific structural features, including covalent CF bonds and sp(3) carbons, play a role in the material's electrochemical behavior.