1. Dry Cell Battery Anode (-) Zn ---> Zn2+ + 2e- Cathode (+)
2 NH e- ---> NH3 + H2

2. Alkaline Battery
Nearly same reactions as in common dry cell, but under basic conditions.
Anode (-): Zn + 2 OH- ---> ZnO + H2O + 2e-
Cathode (+): 2 MnO2 + H2O + 2e- --->
Mn2O3 + 2 OH-

3. Mercury Battery Anode: Zn is reducing agent under basic conditions
Cathode:
HgO + H2O + 2e- ---> Hg OH-

4. Lead Storage Battery Anode (-) Eo = +0.36 V
Pb + HSO > PbSO4 + H+ + 2e-
Cathode (+) Eo = V
PbO2 + HSO H+ + 2e > PbSO4 + 2 H2O

5. Ni-Cad Battery Anode (-) Cd + 2 OH- ---> Cd(OH)2 + 2e- Cathode (+)
NiO(OH) + H2O + e- ---> Ni(OH)2 + OH-

6. H2 as a Fuel Cars can use electricity generated by H2/O2 fuel cells.
H2 carried in tanks or generated from hydrocarbons

7. Hydrogen—Air Fuel Cell
Figure 20.9

8. Ballard Power Systems http://www.ballard.com/
A H2-based fuel cell
Car using a H2 fuel cell

9. Hybrid fuel car,
page 847