You need to know either the lead acid cell or the dry cell, and one of these in detail:
- button cell
- fuel cell
- vanadium redox cell
- lithium cell
- liquid junction photovoltaic
You should be able to draw a diagram of the cells you have chosen, labelling all parts (anode, cathode, electrolyte, structure, etc.) and you have to know oxidation, reduction, overall redox equation, cell voltage, anode, cathode, electrolyte, and maybe the recharging formula if there is one for your cell.