A simple efficient algorithm for molecular simulations of constant potential electrodes.

Area of Science:

• Computational Chemistry
• Materials Science
• Electrochemistry

Background:

• High power and energy storage devices are crucial for electric vehicles and grid applications.
• Supercapacitors offer promising energy storage solutions but face practical challenges.
• Molecular dynamics (MD) simulations are vital for understanding electric double-layer capacitors (EDLCs) at the molecular level but are computationally demanding.

Purpose of the Study:

• To investigate the algorithmic complexity of the constant potential method (CPM) for MD simulations of EDLCs.
• To develop a generalized CPM implementation using standard electrostatics solvers.
• To enhance the computational efficiency and scalability of EDLC simulations.

Main Methods:

• Implemented a generalized CPM using the particle-particle-particle-mesh (P3M) routine from LAMMPS.
• Compared the generalized CPM with a traditional CPM implementation using Ewald summation.
• Performed MD simulations on four test systems to evaluate performance and accuracy.

Main Results:

• The generalized CPM implementation achieves comparable results to the traditional method.
• The new implementation demonstrates substantial speed gains and improved scalability.
• The approach leverages the concept of chemical hardness for integrating generic electrostatics solvers into CPM.

Conclusions:

• A generalized CPM implementation using standard electrostatics solvers is feasible and efficient.
• This method offers a significant improvement in computational speed and scalability for EDLC simulations.
• The findings facilitate more accessible and efficient molecular-level studies of supercapacitors.