Description
decades = log10(currentDensity/exchangeCurrentDensity); overpotential = slopeVoltsPerDecade*decades.
Electrochemical current and potential terms depend on reaction direction, transport geometry and a declared reference state. Named equations apply under specific kinetic or diffusion assumptions; one scaling factor is not a full electrochemical model.
decades = log10(currentDensity/exchangeCurrentDensity); overpotential = slopeVoltsPerDecade*decades.
When to use this tool
Use Tafel Current Decade Overpotential Term when checking one supplied kinetic or transport-model contribution.
How to use the tool and how it works
- Enter currentDensity, exchangeCurrentDensity, slopeVoltsPerDecade. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read decades, overpotential. Use the output convention below.
Require positive currentDensity and exchangeCurrentDensity on one unit basis. decades = log10(currentDensity/exchangeCurrentDensity); overpotential = slopeVoltsPerDecade*decades.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| currentDensity | Current Density | Required. Finite number; strictly above 0. |
| exchangeCurrentDensity | Exchange Current Density | Required. Finite number; strictly above 0. |
| slopeVoltsPerDecade | Slope Volts Per Decade | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| decades | Decades | Required. Finite number. |
| overpotential | Overpotential | Required. Finite number. |
{
"input": {
"currentDensity": 100,
"exchangeCurrentDensity": 1,
"slopeVoltsPerDecade": 0.12
},
"output": {
"decades": 2,
"overpotential": 0.24
}
}Limitations and assumptions
- The slope is supplied and may be signed. This local Tafel term does not validate the kinetic regime, derive exchange current or model full Butler-Volmer behavior.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use a suitable complete model and verified experimental conditions before interpreting a local term as mechanism, performance or a fitted parameter.
References
Similar or alternative tools
- Butler Volmer One Direction Current Term
For anodic return +exchangeCurrent*exp(alpha*n*F*overpotential/(R*T)); otherwise return -exchangeCurrent*exp(-(1-alpha)*n*F*overpotential/(R*T)).
- Randles Sevcik Scan Rate Square Root Factor
ratio = sqrt(scanRate/referenceScanRate); peakCurrent = referencePeakCurrent*ratio.