c5 - fuel cells and rechargeable batteries nathan marshak

C5 - Fuel CELLS AND rechargeable Batteriesnathan marshak

Instead of recharging, you add fuel

Lower environmental impact

Expensive.

FUEL CELLS

Secondary cells are rechargeable.

Store small amounts of energy

Cheap.

BATTERIES

C.5.3 - DESCRIBE HOW A HYDROGEN-OXYGEN FUEL CELL WORKS

C.5.1 - DESCRIBE HOW A HYDROGEN-OXYGEN FUEL CELL WORKSREACTION FOR ACIDIC ELECTROLYTE (e.g.

Phosphoric Acid)Positive: 2O2 + 4e - + 4H+ --> 4H2ONegative: 4H2 --> 4H+ + 4e-

Overall: 2H2 + O2 --> 2H2O

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C.5.1 - DESCRIBE HOW A HYDROGEN-OXYGEN FUEL CELL WORKS

REACTION FOR BASIC ELECTROLYTE (e.g. NaOH)

Positive: H2 + 2OH- --> 2H2O + 2e-

Negative: O2 + 2H2O + 4e- --> 4OH-

Overall: 2H2 + O2 --> 2H2O

Nickel-Cadmium Battery

C.5.2 - DESCRIBE THE WORKINGS OF RECHARGEABLE BATTERIES

Nickel-Cadmium Battery

C.5.2 - DESCRIBE THE WORKINGS OF RECHARGEABLE BATTERIES

REACTION AT NEGATIVE ELECTRODE (CADMIUM)

REACTION AT POSITIVE ELECTRODE (NICKEL)

OVERALL REACTION

C.5.2 - DESCRIBE THE WORKINGS OF RECHARGEABLE BATTERIES

Used in cars to start it.

Battery charges while car is running.

Amount of charge left can be measured

Heavy

Lead Acid Battery

C.5.2 - DESCRIBE THE WORKINGS OF RECHARGEABLE BATTERIES

C.5.2 - DESCRIBE THE WORKINGS OF RECHARGEABLE BATTERIES

Lighter than NiCd

Consumer devices

More voltage than NiCd,

Shorter lifespan than NiCd

Lithium-Ion Battery

C.5.2 - DESCRIBE THE WORKINGS OF RECHARGEABLE BATTERIES

Lithium-Ion Battery

Positive: LiCoO2 --> Li1-xCoO2 + xLi+ +xe-

Negative: C + xLi+ + xe- --> CLix

Overall: LiCoO2 + C --> Li1-xCoO2 + CLix

CHARGING DISCHARGING

C.5.2 - DESCRIBE THE WORKINGS OF RECHARGEABLE BATTERIES