Battery knowledge · Aging and degradation
Activation energy
The energy barrier a reaction must cross, which sets how sensitive its rate is to temperature in the Arrhenius law. Fitted values for lithium-ion aging are typically 20–60 kJ/mol, and they differ for each mechanism. [1]
- Abbreviation
- Eₐ
- Unit
- kJ/mol
Example
Temperature and reaction rate
At 25 °C: 1×. At 35 °C: 1.924×. At 45 °C: 3.554×.
The equation uses kelvin. One activated process is represented, not lifetime.
Explore the graph
Compare an activated process with its rate at 25 °C.
At 25 °C: 1×. At 35 °C: 1.924×. At 45 °C: 3.554×.
k(T)/k(T_ref) = exp[(Eₐ/R)(1/T_ref − 1/T)]
Illustrative model. The equation uses kelvin. One activated process is represented, not lifetime.
Use in Lemonergy
Lemonergy Core equation
Compare reaction rates
Lemonergy Core evaluates this relation.
Equation or tool to use
- arrhenius_factor
Core equation
Inputs & settings
- Temperature (°C)
- Reference temperature (°C)
- Activation energy (J/mol)
This overview identifies the components to use. Follow the example in Lemonergy for their connections and settings.
- Open the lesson and inspect the equation.
- Change one input while holding the others fixed.
Example. At an illustrative 50 kJ/mol activation energy, raising temperature from 25 °C to 35 °C gives a rate factor about 1.92.
Observe. Compare the result with the equation and units.
This factor alone does not predict lifetime or capacity loss.
Open the worked lesson →References & further reading
Technical references
- Arrhenius equation
IUPAC Gold Book · 2025
Technical reference · Temperature dependence of reaction-rate constants and the assumptions about activation energy.
Further reading on this topic
These sources provide broader context; they are not presented as citations for every statement in this entry.
- Lithium ion battery degradation: what you need to know
Physical Chemistry Chemical Physics · 2021
Topic background · Degradation mechanisms, modes, operational effects and their interactions.