Is that possible to use non-linear diffusivity of electrodes in the Many-Particle Model?

[meckwell]

Dear PyBaMM Team,

I wondered whether the MPM in PyBaMM can use the non-linear diffusivity of electrodes in the simulations. I know MPM can use constant diffusivity of electrodes as shown in Toby's paper.

Many thanks for your help in advance.

BW,

Han Yuan (RA Imperial College London)

[valentinsulzer]

Yes, it can. Just give diffusivity as a function of concentration and it will work.

[meckwell]

Thank you Tino for the prompt answer. A quick follow-up, I notice the Double-Particle model mentioned in one of Toby's papers. I was wondering whether the Double-Particle model is available in PyBaMM now. It seems to be as efficient as MPM in some cases but the complexity is reduced.

[valentinsulzer]

Is this just the same as doing a MPM with only 2 grid points in the size dimension @tobykirk ?

[tobykirk]

Yes, although the MPM was not explicitly designed for that, picking 2 grid points in the size dimension gives exactly the double-particle model in that paper. If you use the finite volume discretization and uniform grid spacing in the size domain then, e.g. with R_min=0 and R_max=2' and 2 grid points (or volumes), the 2 particles sizes are the centres of the volumes, so 0.5 and 1.5 (and by choosing R_min, R_max` you can make these whatever you want).

Also, the size distribution f_a(R) is specified as a function currently, but you can just input a piecewise constant function that takes the value you want at each of the two grid points.

[meckwell]

Toby and Tino, Thank you for the anwswers!