CHEM1010 - Week 3: Electrochemistry Part 2

standard reduction potential

the cell potential (voltage) at standard conditions

batteries

these are electrochemical cells

primary batteries

these batteries are one-use only (it is thrown away after use)

secondary batteries

these batteries are rechargeable

dry cell

a regular disposable battery

dry cell

- up to 1.5V
- anode: Zn
- cathode: carbon rod
- electrolyte: moist paste of MnO2 and NH4C

alkaline battery

- up to 1.5V
- anode: Zn/KOH paste
- cathode: C/MnO2
- electrolyte: KOH

alkaline battery

- longer shelf life
- smaller
- higher currents for longer times
- better at lower temperatures

lithium-ion battery

these batteries are used in mobiles computers and cameras

lithium-ion battery

- 3.4 V
- anode: Li in graphite (C)
- cathode: CoO2
- electrolyte: non aqueous Li+

lithium-ion battery

- very lightweight
- can be recharged many times (last two or three years)

lead-storage battery

car battery

lead-storage battery

- 12 V (6 cells joined together)
- anode: Pb
- cathode: PbO2
- electrolyte: sulfuric acid (H2SO4 (aq))

lead-storage battery

- heavy
- very large currents
- reliable for many recharges

fuel cell

used in electric cars

fuel cell

- about 0.7 V each
- anode: C with Ni
- cathode: C with Ni and NiO
- electrolyte: KOH

fuel cell

- needs continuous supply of reactants
- products must be removed immediately