A study on LiFePO₄/graphite cells with built-in Li₄Ti₅O₁₂ reference electrodes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Electrochemical stability is crucial for reliable reference electrodes in lithium-ion cells.
• Existing reference electrode methods can be complex or lack long-term stability.
• Lithium Titanate Oxide (LTO) exhibits superior electrochemical stability.

Purpose of the Study:

• To design and fabricate lithium-ion cells incorporating LTO as a built-in reference electrode.
• To evaluate the performance and characteristics of LTO reference electrodes for in situ monitoring.
• To assess the feasibility of LTO for long-term monitoring of electrochemical parameters.

Main Methods:

• Fabrication of LiFePO4 (LFP)/graphite lithium-ion cells with integrated LTO reference electrodes.
• Measurement and analysis of LTO reference electrode characteristics within the cells.
• In situ monitoring of potentials, Li+ diffusion coefficient (D_Li), and electrochemical impedance spectroscopy (EIS).

Main Results:

• LTO built-in reference electrodes are simple to prepare and demonstrate excellent feasibility.
• Successful long-term in situ monitoring of potentials and electrochemical parameters for both anodes and cathodes.
• LTO electrodes provide reliable data for Li+ diffusion coefficients and EIS information.

Conclusions:

• LTO is a viable and stable material for integrated reference electrodes in lithium-ion cells.
• This approach enables simplified, long-term in situ electrochemical monitoring.
• The use of LTO reference electrodes holds significant potential for various lithium-ion cell chemistries.