London Dispersion and Acido-Basicity of Ni-Rich Cathode Materials Using Inverse Gas Chromatography at Infinite...

Area of Science:

• Materials Science
• Electrochemistry
• Surface Chemistry

Background:

• Lithium-ion batteries (LIBs) are crucial for energy storage, with Ni-rich layered cathodes vital for efficiency.
• Understanding the surface energetics of these cathodes is key to improving interfacial stability.

Purpose of the Study:

• To quantify and compare the surface free-energy components of NCM and NCMA cathodes.
• To correlate surface energy descriptors with electrochemical performance and high-temperature durability.

Main Methods:

• Inverse gas chromatography (IGC) at infinite dilution was used to measure surface free-energy components.
• Full-cell battery tests were conducted at 45 °C to evaluate cycling performance.

Main Results:

• NCM cathodes exhibited dominant Lewis basicity, while Al-incorporated NCMA cathodes showed Lewis acidity.
• NCMA demonstrated reduced London dispersive surface energy and enhanced electrolyte affinity compared to NCM.
• NCMA delivered superior capacity retention (95%) over 100 cycles at 45 °C compared to NCM (92%).

Conclusions:

• Surface energy characterization provides a quantitative framework for designing stable Ni-rich cathodes.
• Aluminum incorporation in NCMA enhances interfacial stability and high-temperature performance by modifying surface energetics.
• These findings enable the development of next-generation LIBs with improved durability.