Energy Density of a Battery

Quantity of energy able to be stored in a battery

What is the energy density of a battery ?


For a battery, refers to the quantity of energy able to be stored and restored during the operation of the equipment.

Useful to know:

is a physical concept used to measure the energy able to be stored in a material or a device: this can be a battery or a superconductor, but also a liquid fuel such as petrol or a solid fuel such as coal, or even a radioactive element such as tritium, uranium or plutonium...

is expressed by unit of mass or based on volume.

We distinguish between the following:

· mass expressed in Wh/kg ;

· volumetric usually measured in J/m3: this indicator is more suited to fuels such as hydrocarbons.

For batteries, is usually given as a function of mass, that is to say in .


Energy density of a battery: details

The of batteries depends on the technology used.

Depending on the components and electrochemical reactions in question, we talk about lead, nickel-cadmium (NiCd), nickel-metal hydride (), lithium-ion (), lithium-polymer (Li-Pol), sodium-sulfur (Na-S) batteries...


Examples and application

Depending on their , batteries can serve the operation of different devices, or be allocated to different uses: mobile phones and laptops, cameras, portable tools, light electric or electric road vehicles...

In this area, technologies are constantly evolving to provide the best possible autonomy.


The energy density of batteries in numbers

With of 0.027 7 kWh/kg, lead batteries are able to start a combustion engine vehicle.

Electric vehicles usually use lithium-ion () accumulator batteries which have a much higher : around 0.2 kWh/kg.


Regulatory framework

Not applicable