Marcus-Hush-Chidsey kinetics at electrode-electrolyte interfaces

Area of Science:

• Electrochemistry
• Materials Science
• Computational Chemistry

Background:

• Electrochemical kinetics at electrode-electrolyte interfaces are crucial for energy devices like fuel cells and batteries.
• Current models often do not fully incorporate electrode electronic structure, limiting predictive accuracy.

Purpose of the Study:

• To develop and apply a unified computational framework for electrochemical kinetics that explicitly includes the electrode's electronic density of states.
• To investigate the impact of electronic structure on reaction rates at various electrode-electrolyte interfaces.

Main Methods:

• Utilized density functional theory (DFT) to calculate the electronic density of states for different electrode materials.
• Integrated DFT-derived electronic density of states into numerical calculations of electrochemical reaction rates.
• Applied the framework to model Li metal electrodeposition/stripping on Li and Cu surfaces, and interfaces involving LiF and Li2CO3.

Main Results:

• Demonstrated significant variations in electrochemical reaction rates based on the electrode's electronic density of states, particularly for Cu with its d-bands.
• Observed minor deviations for Li surfaces with flat densities of states.
• Highlighted the role of the Fermi level in semiconducting interphases (LiF/Li2CO3) and captured discharge/charge asymmetry in reaction rates.

Conclusions:

• The proposed framework provides a more accurate approach to modeling electrochemical kinetics by incorporating electronic structure.
• This method is essential for understanding and optimizing electrode-electrolyte interfaces in energy storage and conversion devices.
• The findings offer insights into material selection and interface design for improved device performance.