Description
For anodic return +exchangeCurrent*exp(alpha*n*F*overpotential/(R*T)); otherwise return -exchangeCurrent*exp(-(1-alpha)*n*F*overpotential/(R*T)).
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.
For anodic return +exchangeCurrent*exp(alpha*n*F*overpotential/(R*T)); otherwise return -exchangeCurrent*exp(-(1-alpha)*n*F*overpotential/(R*T)).
When to use this tool
Use Butler Volmer One Direction Current Term when checking one supplied kinetic or transport-model contribution.
How to use the tool and how it works
- Enter exchangeCurrent, transferCoefficient, electronCount, faradayConstant, overpotential, gasConstant, temperatureK, anodic. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read partialCurrent. Use the output convention below.
Require nonnegative exchangeCurrent, transferCoefficient in [0,1], positive whole electronCount and positive constants and temperatureK. For anodic return +exchangeCurrent*exp(alpha*n*F*overpotential/(R*T)); otherwise return -exchangeCurrent*exp(-(1-alpha)*n*F*overpotential/(R*T)).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| exchangeCurrent | Exchange Current | Required. Finite number; minimum 0. |
| transferCoefficient | Transfer Coefficient | Required. Finite number; minimum 0; maximum 1. |
| electronCount | Electron Count | Required. Safe integer; minimum 1. |
| faradayConstant | Faraday Constant | Required. Finite number; strictly above 0. |
| overpotential | Overpotential | Required. Finite number. |
| gasConstant | Gas Constant | Required. Finite number; strictly above 0. |
| temperatureK | Temperature K | Required. Finite number; strictly above 0. |
| anodic | Select the positive anodic term when true, otherwise the negative cathodic term. | Required. Boolean. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| partialCurrent | Partial Current | Required. Finite number. |
{
"input": {
"exchangeCurrent": 0.01,
"transferCoefficient": 0.5,
"electronCount": 1,
"faradayConstant": 96485.33212331001,
"overpotential": 0.05,
"gasConstant": 8.31446261815324,
"temperatureK": 298.15,
"anodic": true
},
"output": {
"partialCurrent": 0.02645985570641708
}
}Limitations and assumptions
- This returns one directional Butler-Volmer term, not their net sum. Constants and potential must be coherent; transport limits and high-exponent overflow are not physically resolved.
- 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
- Tafel Current Decade Overpotential Term
decades = log10(currentDensity/exchangeCurrentDensity); overpotential = slopeVoltsPerDecade*decades.
- Nernst Reaction Quotient Log Term
potentialCorrection = -gasConstant*temperatureK*ln(reactionQuotient)/(electronCount*faradayConstant).