Traction battery controller employing battery model that efficiently represents complex battery diffusion dynamics

A system, such an electrified vehicle, includes a battery, such as a traction battery. The system further includes a controller configured to control the battery based on (i) a value of a first parameter of a model of the battery taken from electrical measurements of the battery and (ii) a value of a second parameter of the model, dependent on the value of the first parameter, taken from the value of the first parameter.