Cells and Batteries

Chemical cells and batteries convert chemical energy into electrical energy through chemical reactions. This lesson covers how cells work, the difference between cells and batteries, and the factors that affect voltage. This is part of the Energy Changes topic in the AQA GCSE Combined Science Trilogy specification (8464).

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What Is a Chemical Cell?

A chemical cell (also called an electrochemical cell or voltaic cell) is a device that produces a voltage (potential difference) by converting chemical energy into electrical energy.

A basic cell contains:

• Two electrodes made from different metals (or one metal and a non-metal conductor such as carbon).
• An electrolyte — a solution that conducts electricity by allowing ions to flow.

graph TD
    subgraph "Simple Chemical Cell"
        A["Electrode 1 \n(more reactive metal \n— NEGATIVE terminal)"] -->|"Electrons flow \nthrough wire"| B["Electrode 2 \n(less reactive metal \n— POSITIVE terminal)"]
        C["Electrolyte \n(ionic solution)"] -->|"Ions flow \nbetween electrodes"| A
        C -->|"Ions flow \nbetween electrodes"| B
    end