Cells and Batteries

Primary Cells

Non Rechargeable

Secondary Cells

Rechargeable

Primary Equillibrium

Battery Dies

Examples of Primary Cells

Dry cells, alkaline batteries, button cells

Car Batteries

Lead Acid Accumulators

Composition of car battery

Six separate cells joined together in series

Factors for battery life

Loss of reactants, crystallisation, side reactions, impurities, corrosion

Cathode in Galvanic cell

Reduction occurs

Anode in Galvanic cell

Oxidation occurs

Electrolyte

A solution of ions which conducts electricity

Electrode

Electronic conductor with delocalised electrons

Salt Bridge

Electrolytic Conductor

Source for fuel cells

Reactants are supplied from an external source

Efficiency of fuel cells

Very high as chemical energy is directly transformed into electrical energy

Reactants for a fuel cell

Pure oxygen and hydrogen gas

Electrolyte for fuel cells

potassium hydroxide solution

Nature of fuel cell electrode

Catalytic, must keep fuel and oxidant apart while allowing contact with electrolyte

Anode and cathode in a fuel cell

Porous