Battery knowledge · Transport and modelling
Bruggeman relation
The common estimate of effective transport in a porous layer: multiply the bulk conductivity or diffusivity by porosity to the power 1.5. Real electrodes often deviate, so measured tortuosity is preferred when available. [1]
- Relationship
- D_eff = D · ε^1.5
Example
Estimate an effective diffusivity
Using the illustrative relation D_eff = D ε^1.5 with porosity ε = 0.4 gives D_eff ≈ 0.253D. This empirical geometry approximation does not replace a measured tortuosity.
Explore the graph
A Bruggeman relation approximates transport through a porous medium.
At 40% porosity, D_eff is 25.298% of bulk diffusivity.
D_eff = D εᵇ
Illustrative model. An empirical pore-structure assumption; actual tortuosity must be characterized.
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
Technical references
- 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
Technical reference · Porous-electrode transport and insertion-cell modeling; foundational work rather than a specification for a particular commercial cell.
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.