Experiments and Simulation on the Performance of a Liquid-Cooling Thermal Management System including Composite Silica Gel and Mini-Channel Cold Plates for a Battery Module
Round 1
Reviewer 1 Report
Comments for author File: 
Comments.docx
Author Response
The authors report a development of the state-of-the-art in simulation model and experimental methods for the study the temperature uniformity within the battery pack and its effects on efficiency of lithium batteries. The topic is of significant interest for novel batteries for electric devices and the application of composite silica gel (CSG) coupled with cross-structure minichannel cold plate (MCP) as cooling system to control battery temperature with low energy consumption and this topic is appropriate to be published in ''Energies''. The work is of good quality but some extensions of / revisions to the information presented in the communication will be required for it to be suitable for publication, as detailed below.
Comment 1: Key theoretical differences between this work and prior art should be highlighted in the main text (including equations). The following works should be addressed:
[1]- Factor analysis of the uniformity of the transfer current density in vanadium flow battery by an improved three-dimensional transient model. Energy. 2020; 194:116839.
[2]- The effect of flow rate and concentration on the electrical conductivity of slurry electrodes using a coupled computational fluid dynamic and discrete element method (CFD–DEM) model, Electrochemistry Communications, Volume 126, 2021.
[3]- Effects of current collector shape and configuration on charge percolation and electric conductivity of slurry electrodes for electrochemical systems, Energy, Volume 239, Part D, 2022.
[4]- Karzar-Jeddi et al., J. Electrochem. Soc. (2019) 166, A2643
Answer: Great thanks for your guidance on the literature review, which is a significantly important part in the manuscript. We have read the literature you listed here and found that they are indeed of a great help. Key theoretical differences between this work and prior art should be highlighted in the revised manuscript. What’s more, the mentioned references above have also been cited in the revised manuscript.
“In this paper, compared with pure silicon cooling system, a liquid cooling system including silicon assisted with minichannel cold plates with has been proposed, and the impact of flow directions, volume flow rates are studied by experiment and simulation. What’s more, the maximum temperature and temperature difference of the module have been analyzed and discussed. The temperature distribution was analyzed by divided the module into three parts which helps to study the thermal behavior of proposed BTMS. UDF was also applied to obtain more precise heat generation rate of the LIBs. The object of this research would provide an efficient and feasible thermal management system for battery module.”
The recommending references are cited as follow:
- Yuan C, Xing F, Zheng Q, Zhang H, Li X. Factor analysis of the uniformity of the transfer current density in vanadium flow battery by an improved three-dimensional transient model. Energy. 2020; 194: 116839.
- Alireza H., Sherman C.P, Gary R. The effect of flow rate and concentration on the electrical conductivity of slurry electrodes using a coupled computational fluid dynamic and discrete element method (CFD–DEM) model. Electrochem Commun. 2021;126:107017.
- Alireza H., Sherman C.P, Ruchika O, Gary R. Effects of current collector shape and configuration on charge percolation and electric conductivity of slurry electrodes for electrochemical systems. Energy. 2022;239:122313
- Mehdi K.J., Luo H, Peter T.C. , Kelsey B.H. Computational Modeling of Particle Hydrodynamics and Charging Process for the Flowable Electrodes of Carbon Slurry. J Electrochem Soc. 2019;166:A2643
Comment 2: It is better to extend the modelling section. It is more convenient as a reader of the paper to have a table about operating conditions.
Answer: It is very nice of you to mention that and it should be displayed as a table indeed. After careful consideration, we have extended the modelling section and supplemented a table about operating conditions in the revised manuscript, it can be seen as followed:
“As shown in Figure 3, the liquid cooling system coupled with CSG have exhibited optimum cooling performance with synergistic temperature-controlling ability. The liquid cooling battery module contained 25 18650-type ternary batteries, which were assembled with 5 in serial and 5 in parallel. The batteries are distributed uniformly among the module. Towards to CSG module, eight MCPs were inserted into the CSG mold, which were inserted uniformly among the battery module. The specific sizes of the CSG module (110 × 110 × 60 mm) were depicted in Figure 3(b), and the corresponding parameters of the operating conditions are shown in Table 5.”
Table 5. The parameters of the operating conditions in the CSG module
|
Operating condition |
Parameters |
|
Ambient Temperature (℃) |
25/35 |
|
Initial Temperature (℃) |
25/35 |
|
Temperature of Coolant (℃) |
25 |
|
Volume Flow Rate (ml/s) |
6/8/10/12/14 |
|
Discharging rate |
1/2/3 |
Comment 3: The conclusion must include the quantitative results regarding the improvement in the study.
Answer: Thank you for the helpful suggestion. In the revised conclusion, we have supplemented the quantitative results regarding the improvement in the study. It can be seen as follow:
“Aiming at the thermal management system for battery module, the composite silica gel (CSG) coupled with cross-structure minichannel cold plate (MCP) had been proposed and utilized for cylindrical battery module. The CSG and MCPs with different flow rates and various flow channels were analyzed through experiments and simulations. The maximum temperature and temperature difference among battery modules with various cooing structures are compared in detail. The main conclusions are summarized as follow:
- The CSG-LC module with 10 ml∙s-1 flow rate can provide an optimum thermal management effect, which can maintain the temperature of batteries within desirable operating range. The maximum temperatures were controlled below 42 and 49 ℃ under the ambient temperature of 25 and 35 ℃, respectively.
- The temperature uniformity can be obviously affected with the flowing orientation in liquid system. The CSG-LC module with RCC exhibited better cooling effect than that that with SMC. Especially at 3 C discharge rate, the results indicated that the temperature difference can be maintained within 1.5 ℃, and the maximum temperature was below 42 ℃ after six cycling process.
- After six cycling process, the CSG-LC module with RCC structure can maintain the maximum temperature and the temperature difference within suitable temperature range. The experimental and simulating results revealed that the CSG-LC module with RCC structure exhibit an optimum thermal management effect, especially at high discharge rate.”
Comment 4: Please quote computing hardware and simulation runtime associated with the key results, in order for readers to assess the computational demands of the proposed approach
Answer: Thank you for the kind reminding. In order for readers to assess the computational demands of the proposed approach, we have quoted the computing hardware and simulation runtime in the revised manuscript, it can be seen as follow:
“The computer hardware was that the CPU was Intel (R) Xeon (R) Silver 4214R CPU @ 2.40GHz 2.9GHz. besides, the time step size of simulation runtime was 1 s and the maximum iterations was 60 times.”
Author Response File: Author Response.docx
Reviewer 2 Report
This paper contains useful experimental and simulation results. The analysis is sound. It is noted that experiments were carried out in discharge rate of 3C. The battery normally does not heat in discharge mode, but heats up under charging. So, I wonder how the results would change under 3C CHARGING RATE studies.
This needs to be addressed.
Author Response
This paper contains useful experimental and simulation results. The analysis is sound. It is noted that experiments were carried out in discharge rate of 3C. The battery normally does not heat in discharge mode, but heats up under charging. So, I wonder how the results would change under 3C CHARGING RATE studies.
This needs to be addressed.
Answer: Thank you very much for your affirmation agreement of our work. It’s indeed that the fast charging has drawn more attention lately. The experiment was carried out at high discharge rate, the main reason is that the batteries usually generate much more heat during discharge process. The relevant references are summarized as follow:
- Minseok Song, Song-Yul Choe, Parameter sensitivity analysis of a reduced-order electrochemical-thermal model for heat generation rate of lithium-ion batteries. Applied Energy. 2022; 305:117920.
- Mei W, Li H, Zhao C, Sun J, Wang Q. Numerical study on thermal characteristics comparison between charge and discharge process for lithium ion battery. International Journal of Heat and Mass Transfer. 2020; 162:120319.
Nevertheless, according to your suggestion, we have supplemented the temperature variations with the time at 3 C charge rate. As during the charge process, the battery would undergo through a constant voltage stage in which the heat generation rate could vastly decrease. The thermal behavior can result in the instant drop of heat generation. However, the limitation of heat transfer between the batteries and surrounding environment would cause the increase on the temperature difference, the results indicate that the thermal management system is need to provide lower volume flowing rate at 3 C charge rate than at corresponding discharge rate.
Last but not least, we appreciate your kind affirmation on our work and your insightful comments on the aforementioned issues, without which the work cannot be further improved. Great thanks again!
Author Response File: Author Response.docx
