Ragone FR

Ragone plot, diagramme de Ragone

The following slides give a mathematical justification of the well-known Ragone plot representation

For a given electrical storage system, the available energy density is plotted as a function of the power density.
To recover the full energy content of a storage system it's necessary to use the smallest discharge current. The energy losses occur in the internal resistance of the device. High charge/discharge currents will therefore warm up the component. It's generally the main limitation for the volume reduction of a supercapacitor module.
The maximum output power in the load is obtained when the external resistance (load + others) is equal to the internal resistance. In this configuration, half of the energy is burnt inside the storage device.

Source: Garmanage: Roland Gallay