I did a lab where I increased the surface area of the electrodes in a galvanic cell, that resulted in an increase in voltage. However, I have been reading and that is not supposed to happen. I am a bit confused, if you increase the surface area of the electrodes, the rate of reaction as well as the current increases, therefore, if Ohm's law ($V = IR$) is taken into account, the voltage should also increase. But according to some sources, the voltage should remain unchanged.
Could anyone please tell me if an increase in surface area will or will not increase the voltage produced by the cell, and why?