Im kinda confused as to how the reactions at the cathode occur. Most textbooks say something like:
2MnO2 + 2NH4+ + 2e- -> Mn2O3 + H2O + NH3
This is pretty hard to memorise and i did hear from someone that you can actually simplify it down into 2Mn4+ + 2e- -> 2Mn3+. Not sure if this is...