Battery knowledge · Electrochemistry fundamentals
Supercapacitor
A device that stores charge in the electric double layer on high-surface-area carbon rather than in a reaction. It delivers very high power and lasts a million cycles but stores only a few watt-hours per kilogram.
- Also called
- ultracapacitor, EDLC
Example
Capacitor charge and energy
At 5 V: 25 C and 62.5 J.
Ideal constant capacitance; leakage, series resistance and voltage rating excluded.
Explore the graph
Charge rises linearly with voltage; energy rises with voltage squared.
At 5 V: 25 C and 62.5 J.
Q = CV; E = ½CV²
Illustrative model. Ideal constant capacitance; leakage, series resistance and voltage rating excluded.
Use in Lemonergy
Lemonergy Studio blocks
Supercapacitor cell worked example
Causal capacitor state with series loss, leakage and stored energy.
Blocks to use
- Supercapacitor cell
Integrates the internal capacitor voltage from discharge current and leakage. A series resistance produces terminal voltage drop and heat. Stored energy uses the internal capacitor voltage.
Inputs & settings
- Use the parameter values in the block reference.
- Bundled example verified on the production release of 28 October 2026.
This overview identifies the components to use. Follow the example in Lemonergy for their connections and settings.
- Review the block inputs, units and model limits.
- Open the Studio example and run its bundled model.
- Compare the output channels with the numerical checks; change one input and run again.
Example. Use the defaults below with Signed discharge current = 1 A. At 0 s, Terminal voltage is 2.45 V. Additional checks are listed below.
Observe. Inspect the outputs and numerical checks on the block reference page.
Constant capacitance, series resistance and leakage. The external interface is causal; voltage- or temperature-dependent parameters are not included. The example verifies numerical behavior for synthetic parameters. Cell characterization and validation for an intended use are separate tasks.
Open Studio example →References & further reading
Further reading on this topic
These sources provide broader context; they are not presented as citations for every statement in this entry.
- Quantities, Units and Symbols in Physical Chemistry, 3rd edition, 2nd printing
IUPAC · 2011
Topic background · Physical-chemistry notation, thermodynamics, electrochemistry and transport quantities.