[Bug]: Suface form effective conductivity in separator

[Scottmar93]

PyBaMM Version

23.5

Python Version

23.5

Describe the bug

On lines 81 and 85, of pybamm/models/submodels/electrolyte_conductivity/surface_potential_form/full_surface_form_conductivity.py
is seems that the separator porosity is used in the calculation of the effective conductivity in the separator instead of the separator transport efficiency. In the end, I think this is only an order of a few mV errors in the predicted voltage.

Steps to Reproduce

N/A

Relevant log output

No response

[TomTranter]

Separators usually have pretty low tortuosity but it's worth including the change you suggest for sure. I can make the change as I'm familiar with transport efficiency and have just been revamping it. There might be other instances in the code like this I can check for too

[rtimms]

@TomTranter any update on this?

[TomTranter]

Completely forgot about it