Evaluation of Spoiler Model Based on Air Cooling on Lithium-Ion Battery Pack Temperature Uniformity
Round 1
Reviewer 1 Report
The contribution of this study is not clear, unlike what has been mentioned in the introduction section regarding the uniform cooling strategies not been well studied, this problem has been well addressed in many research papers. it is necessary to fairly bring them into light and clarify the novelty and contribution of this research. Also comparisons are required to address this issue.
Some heat generation terms such as radiation heat are being neglected in section 2.2. it is necessary to discuss how those would affect the performance of the heat management system.
The analysis of the experiments could be further expanded for a number of different scenarios to show the merits of the method. the conclusion section is also very brief and not much motivating one to pick such approach over hundreds of already existing methods. It is necessary to highlight the advantages and the limitation of the proposed method.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
- It is suggested to add a nomenclature table to the article.
- Explanation of each figure should be presented right after that figure.
- The three models that are studied can be elaborated in more details.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 3 Report
Linguistically well written.
Description partly not precise or simply wrong.
The compared cooling path designs have great improvement potential. Especially with a CFD tool the entrance flow from the supply chamber to the battery camber could be designed evenly over the bottom surface. Of cause, the exhaust channel has to be considered as well.
Line 13 This sentence does not make sense at all.
“Especially, EVs are powered by high-capacity energy due to the high voltage of the battery.”
Line 28 Not true, why should this be the case? Depends on the built and load profile not application.
“In particular, because the battery systems for vehicles generate more heat than other battery systems,”
Line 37 Wrong: the cell chemistry defines the voltage window per cell, regardless the cell built.
“requiring more cells to generate high voltages,”
Line 39 It is not the conduction, it is the environment of each cell, the boundary conditions. Think of the heat flow not conduction.
“owing to conduction”
Line 40 80% of the heat is taken out on the bottom of the cell and have there for a much smaller surface than pouch cells. As you said, they have less density. Pouch cells can be more compact. To get the heat out isn’t easy as well, it Is easier to access cooling surfaces but there is more heat in a volume to the battery pack because can be smaller. You may describe a bit differently.
“cylindrical batteries depend more on the performance of the cooling system than other battery cell types.”
Line 53 Not correct. If the busbars disturb you have a mistake in the design of the cooling flow, that has nothing to do with the forced flow or convection.
“However, forced cooling on battery cells is not suitable for actual products because the flow is changed by the busbar.”
Fig. 3 is not quite clear. How is the flow between the left and the right spoiler in (c)? in (b) the flow depends on the relation between the supply channel and the openings to the battery chamber. It could be uniformly as well. Of course, in a small supply chamber the spoilers help with uniformity but increase flow resistance in the supply chamber. Show the 3d positioning of the spoilers. It is not clear.
Line 144 2D Model? Show the mesh!
“The number of generated elements was approximately 450,000.”
Line 168 How is the heat sink built?
Fig. 6 Shows clearly the faulty z-design, there is too much leakage at the BMS. Optimizing the opening width of z Design would improve the temperature distribution even further.
The heat sink is a metal blade in the exhaust channel?
Fig. 7d confusing
Line 246 How was the camera applied? After opening the case? How to access cells 10 to 18?
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 4 Report
This article deals with the research on Evaluation of Spoiler Model Based on Air Cooling on Lithium-ion Battery Pack. The Battery Simulation Modeling is presented in section (II) and Simulation Results have discussed in section (III). The following section (IV) is devoted to Battery Cooling Experiment.
In order to improve the paper, please take into account the following remarks:
- Page 1, you have noted that “cylindrical batteries have a lower energy density than other types of battery, requiring more cells to generate high capacity, as well as extra space”. It is not exactly. For instance, the energy density of the battery (with 18650 cells) for the TESLA S vehicle is equal to 157Wh/kg whereas the energy density of the battery (with prismatic cells) for the BMW i3 is equal to 132 Wh/kg.
- Page 1, line 43, there is a dot not justify “ …other cooling methods., and phase change….’
- In table 1, the maximum discharge current of 18650 battery cell is equal to 5.2A. In section 4, for the experimental tests of the battery 3S9P, the maximum discharge current was set to 20A (it is not the maximum discharge C-rate for the cell). Why did you choose this value?
Author Response
We appreciate your for the good review!
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
I am happy with the modifications
Author Response
We appreciate your for the good review!
Reviewer 3 Report
Line 13 This sentence does not make sense at all and was NOT improved.
“Especially, EVs are powered by high-capacity energy due to the high voltage of the battery.”
high-capacity batteries not energy
high voltage does reduce power losses
The context does not make sense.
This is a scientific publication. Please pay attention to the correct reproduction of physical relationships!
“However, forced cooling on battery cells is not suitable for actual products because the flow is changed by the busbar.”
This is a citation. OK, but nonsense does not get better by repeating it. This could be in a specific case, generally it is wrong.
Line 284 Spoiler not Boiler
Author Response
We appreciate your for the good review!
Author Response File: Author Response.docx
Reviewer 4 Report
Thanks for the responses and the corrections made to the review. I consider that the article has been improved and it is ready for publication.
