Heat Generation in Batteries
Every battery generates heat during operation. The main sources include:
In small cells or at low currents, the generated heat may dissipate naturally. However, in high-power or large-capacity applications, heat can accumulate, leading to temperature rises that affect battery performance and accelerate degradation.
Thermal Model Types
Thermal models are coupled with electrochemical models (such as the Doyle-Fuller-Newman model): the electrochemical processes dictate how much heat is generated, while the battery temperature affects transport properties inside the cell.Lumped Thermal Models
These treat the entire battery as having a uniform temperature. Advantages:- Simpler and computationally efficient
- Suitable for real-time battery management systems (BMS)
- Systems where temperature gradients are minimal
- Applications requiring fast calculations
Spatially Distributed Models
These account for temperature variations within the battery. Depending on the desired level of resolution, these models can capture:- Temperature differences across the current collector or cell thickness
- Detailed variations within each battery layer
- Large-format cells
- High-power applications where internal temperature gradients significantly impact performance and safety
Choosing the Right Model
In practice, many battery management systems use simplified models for real-time control, while more detailed models are employed for design and analysis.
Impact on Battery Aging
Temperature control isn’t just about efficiency—it directly influences battery aging. Elevated temperatures accelerate chemical degradation processes, leading to:- Capacity fade
- Increased internal resistance
Related Topics
- Internal Resistance—the primary source of heat generation
- State of Health—how temperature affects battery aging
- Degradation Overview—mechanisms accelerated by high temperature
- Lithium Plating—a degradation mechanism affected by low temperature
- Battery Packs—thermal management at the pack level