Battery knowledge · Transport and modelling
Randles circuit
The classic equivalent circuit for one electrode interface: electrolyte resistance in series with a double-layer capacitance that shunts the charge-transfer resistance and a Warburg diffusion element. It is the template for reading an impedance spectrum.
Example
Read an impedance semicircle
High-frequency intercept: 10 mΩ. Arc width: 30 mΩ. Low-frequency intercept: 40 mΩ.
No diffusion tail or inductive loop. The plotted aspect ratio may distort the semicircle.
Explore the graph
A series resistance plus one parallel RC branch gives a single semicircle.
High-frequency intercept: 10 mΩ. Arc width: 30 mΩ. Low-frequency intercept: 40 mΩ.
Z = R₀ + R₁ / (1 + jωR₁C)
Illustrative model. No diffusion tail or inductive loop. The plotted aspect ratio may distort the semicircle.
Use in Lemonergy
Specify phase, direction and boundaries.
This is a reference concept. No executable Lemonergy block has been verified for this term.
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.
- Modeling of Galvanostatic Charge and Discharge of the Lithium/Polymer/Insertion Cell
Marc Doyle, Thomas F. Fuller, John Newman · Journal of The Electrochemical Society · 1993
Topic background · Porous-electrode transport and insertion-cell modeling; foundational work rather than a specification for a particular commercial cell.
- Quantities, Units and Symbols in Physical Chemistry, 3rd edition, 2nd printing
IUPAC · 2011
Topic background · Physical-chemistry notation, thermodynamics, electrochemistry and transport quantities.