Documentation

## Lithium-Ion Temperature Dependent Battery Model

This example shows the impact of temperature on a 7.2 V, 5.4 Ah, Lithium-Ion battery module.

Souleman Njoya M., Louis-A. Dessaint (Ecole de technologie superieure, Montreal)

### Circuit Description

This demo illustrates the effect of temperature on the performance of a 7.2 V, 5.4 Ah Lithium-Ion battery model. The model (which includes the impact of cell/ambient temperature on the voltage, capacity and resistance) is submitted to a variable ambient temperature during a discharge and charge process. Its performance is compared to the case where the impact of temperature is neglected. As observed from the Scope, the temperature dependent battery model performs close to reality. As the cell/internal temperature increases/decreases due to charge(or discharge) heat losses and ambient temperature variations, the output voltage and capacity also increase/decrease.

### Simulation

The demonstration shows the performance of the temperature dependent Lithium-Ion battery model (Battery A) when the ambient temperature is varied from 20 degrees C to -20 degrees C and then to 0 degrees C. Battery B represents the case where the effect of temperature is neglected. Start the Simulation and open the Scope to view all signals.

At t = 0 s, the Battery A and B are discharged with 2 A at ambient temperature of 20 degrees C.

At t = 150 s, the internal temperature has increased to its steady state value of 29.2 degrees due to heat losses from the discharge process. This causes the output voltage of Battery A to slightly increase, while battery B output voltage continues to decrease.

At t = 1000 s, the ambient temperature is decreased to -20 degrees C. This causes the output voltage of Battery A to greatly decrease as the internal temperature decreases rapidly. Also the SOC of Battery A decreases due to the reduction of battery capacity. The battery B output voltage continues to decrease slowly to its steady state voltage.

At t = 2000 s, the ambient temperature is increased from -20 degrees C to 0 degrees C. As the internal temperature increases, the output voltage of Battery A increases. Also, as the capacity increases, the SOC of Battery A increases. The Battery B output voltage remains constant to its steady state value.

At t = 2500 s, the Battery A and B are charged with 3 A at ambient temperature of 0 degrees C. This causes the internal temperature to increase due to heat losses during the charge process, which increases the charging voltage of Battery A. Afterwards, Battery A and B continue to charge up until fully charged.

### References

1. O. Tremblay, L.-A. Dessaint, A.-I. Dekkiche, A Generic Battery Model for the Dynamic Simulation of Hybrid Electric Vehicles, 2007 IEEE Vehicle Power and Propulsion Conference, September 9-13, 2007, Arlington/Texas, USA.

3. Cong Zhu, Xinghu Li, Lingjun Song, Liming Xiang, Development of a theoretically based thermal model for lithium ion battery pack, Journal of Power Sources, Volume 223, 1 February 2013, Pages 155-164.

2. L.H. Saw, K. Somasundaram, Y. Ye, A.A.O. Tay, Electro-thermal analysis of Lithium Iron Phosphate battery for electric vehicles, Journal of Power Sources, Volume 249, 1 March 2014, Pages 231-238.