Electrode Potentials and Electrochemical Cells: Commercial Applications of Electrochemical Cells Flashcards
1
Q
What kind of cells are there?
A
- Non-rechargeable
- Rechargeable
2
Q
What type of reactions take place in non-rechargeable cells?
A
- Irreversible
3
Q
What type of reactions take place in rechargeable cells?
A
- Reversible
4
Q
Where are lithium-ion cells used?
A
- Mobile phones
- Laptops
5
Q
What reactions occur in a lithium-ion cell?
A
• Cathode
- Li+ (aq) + CoO2 (s) + e- ⇌ Li+[CoO2]- (s)
• Anode
- Li (s) ⇌ Li+ (aq) + e-
6
Q
How are rechargeable cells recharged?
A
- Current is applied
- Forces electrons to move in opposite direction
- Causes reaction to reverse, recharging the cell
7
Q
What are fuel cells?
A
- Type of electrochemical cell that can generate an electrical current without needing to be recharged
8
Q
What reactions occur in an alkaline hydrogen-oxygen fuel cell?
A
• Cathode
- H2 (g) + 2OH- (aq) → 2H2O (l) + 2e-
• Anode
- O2 (g) + 2H2O (l) + 4e- → 4OH- (aq)
9
Q
What are the benefits of fuel cells?
A
- More efficient, convert more of their available energy into other energy stores
- Only waste product is water, so no toxic chemicals
- Don’t need to be recharged
10
Q
What are the cons of fuel cells?
A
- Need energy to produce supply of hydrogen
- E.g electrolysis of water may be generated with fossil fuels
- Hydrogen is highly flammable
- Hydrogen fuel infrastructure not widely available for hydrogen fuel for cars