Transfer function of current block in 2RC ECM model

I need to model a cell using Equivalent ciruit model. I need to use transfer function to model electrical elements (Resistor, capacitor, etc). With help from the internet, I could some how manage to replicate the figure in Simulink (with transfer functions). Straight Forward.

The next challenge is, the cell receive current as Input. (from Power profile). I do not know how to approach here. I need to add a current block, where I can feed input. Is there someway to replicate current block by voltage and Resistor relation? In, general I see transfer function has input and output of same form (say for example, Voltage) but for Figure(with_I_as_input.png), I do not find examples close to what I want to model in the internet.

I need to use Simulink transfer function for the task, Simscape electrical elements cannot be used for some reasons.

Can someone give direction here?

I have added the transfer function for 2RC ECM without current block. It might have some errors, I am not sure. To this current input must be added.

Answer 1

[Sam Chak]

@Vishnubharathi thirupathi

Since it is a RC circuit, can you write up some equations using Kirchhoff's circuit laws?

The equations can be Laplace-transformed into the transfer function model that you want.

Refer to a good example here:

https://www.mathworks.com/help/symbolic/solve-differential-equations-using-laplace-transform.html

[Vishnubharathi thirupathi]

May be I need to add a note, the current block which I need to include behaves as load current/external load.