Difference between "bulk solvent concentration" and "EC initial concentration in electrolyte" parameters.

[RobyG1]

Hi,

I am new to PyBaMM and I want to be sure I understand the difference between those two parameters:

• "bulk solvent concentration"
• "EC initial concentration in electrolyte"

In the Chen2020 parameters set, the bulk solvent concentration is 2636 mol/m^3 and the EC initial concentration in electrolyte is 4541 mol/m^3. First, I am not sure why the first number is lower than the second one. Second, from Ploehn2004, they mention for the bulk solvent concentration: "we assume that c_eq equals the concentration of the reactive component S in the electolyte solution". To me this means this is the concentration of EC.

I would appreciate any help that could clarify this.

Thanks!