Overpotential Calculator
Calculate electrode overpotential using Tafel equation and Butler-Volmer kinetics for electrochemical processes.
Overpotential Parameters
Tafel Equation:
eta = a + b * log(i)
where a and b are Tafel parameters specific to electrode material
Quick Current Densities:
Overpotential (Tafel)
-0.0300 V
Efficiency Loss: -2.5%
aTafel a
0.030 V
bTafel b
0.030 V/dec
i0Exchange i0
1.00e-3 A/cm2
BVButler-Volmer
0.1183 V
Calculation:
eta = 0.030 + 0.030 * log(0.01)
eta = 0.030 + 0.030 * (-2.00)
eta = -0.0300 V
Physical Interpretation:
- Higher overpotential = more energy wasted
- Low i0 = sluggish electrode kinetics
- Low b = faster approach to limiting current
Types of Overpotential
Activation
Energy barrier for electron transfer reaction at electrode surface.
Concentration
Mass transport limitations near electrode surface.
Resistance
Ohmic losses in electrolyte and electrode materials.