Operando Depth-Resolved Measurement of Solvation Entropy, Interfacial Transport, and Charge-Transfer Kinetics in...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Understanding lithium-ion battery performance requires insight into electrode-electrolyte interfaces.
• Direct, depth-resolved operando diagnosis of these buried interfaces is challenging.
• Conventional methods struggle to resolve key interfacial properties in working batteries.

Purpose of the Study:

• To develop a novel operando technique for diagnosing buried electrode-electrolyte interfaces in lithium-ion batteries.
• To enable depth-resolved measurement of interfacial properties like solvation entropy and resistance.
• To provide essential data for mechanistic studies and accelerated battery design.

Main Methods:

• Development of multiharmonic electro-thermal spectroscopy (METS).
• Utilizing frequency-dependent, thermal-wave sensing.
• Employing interface-specific modeling and comparison with electrochemical impedance spectroscopy (EIS).

Main Results:

• METS enables depth-resolved measurement of solvation entropy, interfacial transport resistance, charge-transfer resistance, and SEI resistance.
• The technique uniquely attributes interfacial properties to specific electrodes within practical lithium-ion batteries.
• Validation against traditional EIS confirms METS's accuracy.

Conclusions:

• METS offers unprecedented capabilities for spatially and temporally resolving interfacial processes in real time.
• This technique is crucial for mechanistic studies of battery degradation.
• METS facilitates the rapid development of next-generation energy storage systems.