Thank you for your good wishes.
What you are trying to do is possible, but using Simscape makes it much easier because it works with acausal physical networks instead of signals. This means that you assemble your model as if you were drawing a schematic of the system. Doing it using only Simulink requires the implementation of the physical equations in mathematical form and also establishing their interactions.
The way to programmatically construct a model with a user-defined number of elements (battery cells in this case) is to use the MATLAB functions add_block and add_line. These functions bring library blocks onto the canvas and connect them, respectively. This is applicable to any Simulink component, including Simscape.
Please see the attachment I created as a simple example.
Please let me know if you have any further question.