Effect of Temperature on the Aging rate of Li Ion Battery Operating above Room Temperature.

Feng Leng,Michael Pecht,Cher Ming Tan

doi:10.1038/srep12967

Abstract

Temperature is known to have a significant impact on the performance, safety, and cycle lifetime of lithium-ion batteries (LiB). However, the comprehensive effects of temperature on the cyclic aging rate of LiB have yet to be found. We use an electrochemistry-based model (ECBE) here to measure the effects on the aging behavior of cycled LiB operating within the temperature range of 25 °C to 55 °C. The increasing degradation rate of the maximum charge storage of LiB during cycling at elevated temperature is found to relate mainly to the degradations at the electrodes, and that the degradation of LCO cathode is larger than graphite anode at elevated temperature. In particular, the formation and modification of the surface films on the electrodes as well as structural/phase changes of the LCO electrode, as reported in the literatures, are found to be the main contributors to the increasing degradation rate of the maximum charge storage of LiB with temperature for the specific operating temperature range. Larger increases in the Warburg elements and cell impedance are also found with cycling at higher temperature, but they do not seriously affect the state of health (SoH) of LiB as shown in this work.

Highlights

Et al.8. studied the capacity fade of Sony 18650 cells with LiCoO2/Graphite electrode materials at room temperature, 45 °C, 50 °C and 55 °C respectively
While Bodness et al.[9] and Thomas et al.[10] investigated the aging of various cell components at elevated temperature and provided useful information for the aging of Lithium-ion batteries (LiB) cycled at high temperature, their techniques involve disassembly of battery and complex instrument that is costly and not portable, making their methods not possible to be implemented in some practical applications which required a real time investigation such as those demanded by the battery management system (BMS) of electric vehicle (EV)
The increasing degradation rate of Qm during cycling with increasing temperature is because the degradation mechanisms of irreversible capacity loss are accelerated by elevated temperature, as reported in many studies[15,17]

Summary

Characteristics Prismatic cell

At 45 °C and fourth cell at 55 °C. The terminal voltage and current of the cells are monitored on-line to ensure safety and recorded every 30s as input parameters for fitting process. With these algorithms, a good agreement can be seen between the computed and experimental discharge curves. SoC is computed as Q/Qm where Qm is the initial maximum charge stored in LiB and it is counting computed method.

Results and Analysis

Conclusion

Additional Information