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Batteries
Beginner
Chemical cells that supply current.
Chemical energy converts directly into electrical energy through redox reactions at two electrodes. Primary cells are used once, secondary cells recharge.
Li-ion cells have 3.7 V and about 250 Wh/kg.
Capacity in Ah and energy in Wh differ.
In more detail
A battery converts chemical energy into electrical energy through redox reactions between electrodes and an electrolyte. Primary batteries are single-use, while secondary batteries can be recharged.
Real-world uses
- Phones and laptops use rechargeable lithium-ion batteries.
- Torches and remote controls use single-use alkaline cells.
- Phones, torches and electric cars rely on batteries, which convert chemical energy into electrical energy.
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Frequently asked questions
What is the difference between a cell and a battery?
A battery is several cells connected together, though the terms are often used interchangeably.
Why do batteries run down?
Reactants are consumed, and internal resistance increases over time.
What is the difference between a cell and a battery?
A cell is a single electrochemical unit, while a battery is several cells connected together.
Related topics in Current Electricity & Circuits
Electrolysis · Faraday's laws of electrolysis · Thermoelectric effects · Charging and discharging batteries · Electric circuits symbols · Short circuit