Chemical cells and fuel cells (chemistry only) Key Terms

fuel cell

A device that converts chemical energy from a fuel into electrical energy through electrochemical reactions.

potential difference

The difference in electric potential between two points in a circuit, which drives the flow of electric current.

Overall reaction

The complete chemical change that occurs in a hydrogen fuel cell, where hydrogen gas is oxidised at the anode to produce water at the cathode.

Oxidation of hydrogen

The loss of electrons by hydrogen atoms in the fuel cell, forming protons that combine with oxygen to generate water.

hydrogen fuel cell

A device that converts chemical energy from hydrogen and oxygen into electrical energy through electrochemical reactions.

rechargeable cell

A type of cell that can be recharged by reversing the chemical reactions that occur during discharge.

Hydrogen fuel cell

An electrochemical device that generates electricity by oxidising hydrogen gas at the anode and reducing oxygen at the cathode, producing water as the sole product.

Rechargeable battery

A type of electrochemical cell whose chemical reactions can be reversed by applying an external electric current, allowing the cell to be recharged and reused.

Fuel supply

The source of energy that is fed into a fuel cell, typically hydrogen gas or another combustible fuel, which is oxidised to generate electricity.

Rechargeability

The ability of a cell or battery to have its chemical reactions reversed by an external electrical current, allowing it to be used repeatedly.

Hydrogen electrode

The electrode in a hydrogen fuel cell where hydrogen gas is oxidised to protons and electrons.

Half‑cell reaction

The balanced chemical equation that describes the oxidation or reduction occurring at one electrode in an electrochemical cell.

half equation

An equation that shows the reduction or oxidation process occurring at an electrode in an electrochemical cell.

hydrogen fuel cell

A device that converts chemical energy from hydrogen and oxygen into electrical energy through electrochemical reactions.

hydrogen fuel cell

A device that converts chemical energy from hydrogen and oxygen into electrical energy, producing water as a byproduct.

half equation

An equation that shows the oxidation or reduction process occurring at an electrode during an electrochemical reaction.