Phase changing material in batteryPresentation_RP & SC.pptx

PCM for battery

1. Presentation on Developments in battery thermal management systems for Electric Vehicles Indian Institute of Technology Jodhpur Course Instructor : Dr. Durgamadhab Mishra Materials For Electrochemical Energy Conversion and Storage: Batteries (Course Code: PHL7521) Presented By: Ratul Panja (M22CI009) Shailendra Chauhan (M22CI010) MTech in Infrastructure Engineering with Specialization in Energy Department of Civil and Infrastructure Engineering 1

2. NARROW DOWN APPROACH EV Components Battery Technology Charging Infrastructure Motor Drivetrain Energy Management Software Materials Alternative Power Source Infrastructure and Grid Integration Battery Technology Anode and Cathode Materials Electrolyte Chemistry Solid-State Batteries Battery Thermal Management Systems (BTMS) Fast Charging Technology Battery Management Systems (BMS) Recycling and Sustainability BTMS Air-cooled BTMS Liquid-cooled BTMS PCM-based BTMS Heat pipe based BTMS Refrigeration based BTMS Hybrid BTMS Others 2

3. INTRODUCTION A battery pack consists of several battery cells arranged in different configurations of series, parallel, and combination of the same. Lithium-ion batteries are the most preferable one for commercial purpose as it dominates the performance of other types of batteries. This performance is dependent on electrochemical process. As Arrhenius law states rate of chemical reaction increases exponentially with the temperature rise. 3

4. EFFECT OF TEMPERATURE ON BATTERY PERFORMANCE The cycle life of a Li-ion battery is 3323 cycles at 45ºC , falling significantly to 1037 cycles at 60ºC . The battery cells lost more than 60% of initial power at 50ºC after 800 cycles Lost 70% at 55ºC after 500 cycles. With high temperature, self-discharge of the battery occurs TEMPERATURE The viscosity of the electrolyte increases. Ionic conductivity decreases Increase in the internal resistance of the battery pack. An increase in charge-transfer resistance, lithium plating, and lithium dendrites. TEMPERATURE 4

5. EFFECT OF TEMPERATURE ON BATTERY PERFORMANCE (Contd.) THERMAL RUNWAY The desired operating temperature range of the battery is 15ºC to 35ºC or 20ºC to 40ºC The maximum temperature difference ( ΔTmax ) should be less than 5ºC from module to module to maintain a uniform temperature distribution STANDARD OPERATION 5

6. BROADER CLASSIFICATION OF BTMS 6

7. AIR-COOLED BTMS Simplicity Low cost Electrical Safety Lightweight No-leakage concern Easier maintenance Demand of a high temperature working environment Larger battery pack cooling High charge-discharge cycles Exhaust fans Blowers Modified air-flow channels Fins structure EV models such as BYD E6, Toyota Prius, Nissan Leaf, etc. Applications 7

8. AIR-COOLED BTMS (Contd.) Series Cooling Configuration Simple channel- This will lead to that the cell temperature near the exit is obviously higher than that near the inlet – NON UNIFORM COOLING Wedged channel - Have an enlarged inlet, a shrunken outlet, and the cross section area of channel contracts gradually from inlet to outlet - the cell near inlet has lower surface heat transfer coefficient whereas the cell near outlet has a higher surface heat transfer coefficient, thus the maximum temperature difference between cells decrease. Simple channel with reciprocating cooling - Two identical fans were placed at inlet and outlet of the tunnel and produced reciprocating flow by activating and deactivating them in turn- temperature difference among cells was reduce from 1.3ºC to 0.6ºC 8

9. AIR-COOLED BTMS (Contd.) Parallel Cooling Configuration Z-parallel configuration- The ΔT max between the cells is dropped by 45% and 41% for a fixed inlet flow rate of air and fixed power consumption respectively under constant heat generation after optimization. U-parallel configuration - After optimization of the inlet and outlet widths, ΔT max between the cells is dropped by 70%. 9

10. AIR-COOLED BTMS (Contd.) Series-Parallel Mixed Cooling Configuration Aligned Arrangement- Under a specified air flow rate, the maximum temperature rise was inverse to the longitudinal interval for the aligned arrays. A larger longitudinal spacing can weaken influence of the stagnant region existing between each two cells in a longitudinal row, thus can enhance cell heat dissipation. Staggered Arrangement - Under a specified air flow rate, the maximum temperature rise was proportional to the longitudinal interval for the staggered arrays. Trapezoid configuration- Follows the wedged channel mechanism. The maximum temperature and maximum temperature difference in the battery pack was always below +40ºC and 6.6 ºC. 10

11. LIQUID-COOLED BTMS Liquid-cooling can be 3500 times more efficient than air cooling It can save up to 40% parasitic energy Liquid-cooling can reduce the noise level Battery pack can be more compact without decreasing cooling efficiency Complexity Cost Potential leakage Tube cooling Cold plate cooling with mini/micro channels Jacket cooling 11

12. LIQUID-COOLED BTMS (Contd.) It can cool the entire surface of cell and this helps improve temperature uniformity. It mitigates local heating effect at positive and negative electrodes. Characteristics P otential C ooling Media Materials Problems to be addressed Materials Electrical short Dielectric like deionized water, silicon-based oils or mineral oils Direct Cooling 12

13. LIQUID-COOLED BTMS (Contd.) Advantage of Direct Cooling over air-cooling For the same flow rate, the heat-transfer rate of oil was much higher than that of air due to thinner boundary layer and higher fluid thermal conductivity. It can be seen that direct oil cooling was still more thermal efficient than direct air cooling even though direct oil cooling kept low flow rate to make compromise between pressure loss and thermal efficiency. 13

14. LIQUID-COOLED BTMS (Contd.) Materials Problems to be addressed Materials Electrical short Mixture of water and ethylene glycol Indirect Cooling Wavy tubes C oolant jacket L iquid cooled cylinder Cold plate with mini-channels C ombination of fin and cold plate with mini-channels 14

15. LIQUID-COOLED BTMS (Contd.) Used Mechanisms Description Cooling Effect Application Wavy tubes Series cooling configuration. Safer based on mechanical and electrical evaluation Thermally conductive yet electrically isolative materials need to be arranged to fill the void space between cells and tube Tesla Coolant Jacket Series-parallel cooling configuration. Temperature uniformity will be improved. More thermally effective than Wavy tubes BMW, and LG Chem L iquid cooled cylinder (LCC) Parallel cooling configuration Maximum temperature could be controlled under +40ºC at 5C discharging rate Local temperature difference was 5ºC by just increasing the mass flow rate of water Tesla Model S Cold plate with mini-channels Due to that the plate surface is flat, it is suitable for cooling prismatic cell Maximum temperature and local temperature difference could be controlled under +35ºC and 5ºC respectively. Chevrolet Volt Combination of fin and cold plate Fins are placed between cells and the bases of fins connect to cold plate to form an integral heat sink The metal fins facilitate the heat dissipation from cells to cold plates Maximum cell temperature could be controlled below maximum cell temperature could be controlled below +35ºC Maximum temperature difference is 2 ºC . - 15

16. PCM-BASED COOLING BTMS PCM is a substance that undergoes a phase transition (usually from solid to liquid or vice versa) at a specific temperature. This property allows PCM to absorb and release a significant amount of thermal energy during the phase transition, providing an effective means of thermal management. 16

17. PCM-BASED COOLING BTMS (Contd.) High Heat Absorption Capacity Reduced Dependency on Active Cooling Enhanced Safety Advantages of PCM-based EV battery cooling Selection of PCM for EV battery cooling Material having lower melting point High thermal conductivity High Chemical Stability High Thermal Cycling Stability High Latent Heat of Fusion Materials used as PCM Graphite Fibers nano-PCM (Metal Nanoparticles +PCM) 17

18. CONCLUSION Temperature range and temperature variation are two critical parameters influencing the battery pack performance. The ambient temperature may vary from -35ºC to +50ºC in different regions, climates and seasons, whereas the desired temperature range of battery is about +15ºC~+35ºC. These three processes dominate the battery temperature heat generation, heat transport, and heat dissipation. Compared to series configuration, parallel and mixed series-parallel configurations have been proved to be more effective to mitigate the temperature difference between cells. Direct liquid cooling, especially liquid immersion cooling, emerges as a promising cooling technology for BTM. Compared to indirect liquid cooling, the cooling efficiency improves due to increased contact area between cells and liquid coolant and removal of thermal-conduction resistance and thermal contact resistance. At present, the dominant battery cooling strategies are based on air, liquid and PCM 18

19. References Developments in battery thermal management systems for electric vehicles: A technical review - Pranjali R. Tete *, Mahendra M. Gupta, Sandeep S. Joshi, 5 January 2021 https://doi.org/10.1016/j.est.2021.102255 A review on battery thermal management in electric vehicle application - Guodong Xia*, Lei Cao, Guanglong Bi, 12 September 2017 http://dx.doi.org/10.1016/j.jpowsour.2017.09.046 D. Chen, J. Jiang, G. Kim, et al., Comparison of different cooling methods for lithium ion battery cells, Appl. Therm. Eng. 94 (2016) 846e854. H. Wang, F. He, L. Ma, Experimental and modelling study of controller-based thermal management of battery modules under dynamic loads, Int. J. Heat. Mass Tran 103 (2016) 154e164. T. Wang, K.J. Tseng, J. Zhao, et al., Thermal investigation of lithium-ion battery module with different cell arrangement structures and forced air cooling strategies, Appl. Energy 134 (2014) 229e238 N. Yang, X. Zhang, G. Li, D. Hua, Assessment of the forced air-cooling performance for cylindrical lithium-ion battery packs: a comparative analysis between aligned and staggered cell arrangements, Appl. Therm. Eng. 80 (2015) 55e65. 19

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