Polarization

Example

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Use in Lemonergy

Separate regulation from availability.

This is a reference concept. No executable Lemonergy block has been verified for this term.

Connected concepts

Related concepts from the knowledge graph. Connections show context, not cause and effect. Hover or focus a linked term for its definition.

Concentration polarization

Voltage loss that arises when reactant is consumed faster than diffusion can replace it, so the concentration at the surface differs from the bulk. It dominates at high current and low temperature and recovers slowly when current stops.

IR drop

The instant step in terminal voltage when current starts or stops, equal to current times internal resistance. It is lost as heat and is the reason a cell’s voltage under load sits below its open-circuit voltage.

Open-circuit voltage

The voltage across a cell’s terminals when no current flows and the cell has rested long enough for the voltage to settle. It depends on state of charge and temperature, and a cell whose open-circuit voltage falls unusually fast in storage may have an internal short.

Overpotential

The extra voltage, beyond the equilibrium potential, needed to drive a reaction at a given rate at one electrode. Activation overpotential pays for charge transfer, concentration overpotential for depleted reactant, and both appear as polarization at the terminals.

Polarisation curve

A plot of cell voltage against current or current density, showing how far voltage falls below its open-circuit value as load rises. Standard for fuel cells, it shows three regions: a steep early drop from activation losses, a straight ohmic section, and a final collapse when mass transport cannot keep up. For batteries it is built from pulse tests.

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.

1. Lithium-ion battery fast charging: A review

   Anna Tomaszewska et al. · eTransportation · 2019

   Topic background · CC-CV and alternative charging protocols, transport limitations, degradation and thermal implications; results depend on cell and test conditions. Software behavior is documented separately in Lemonergy block references.