Characterization of Lithium-Ion Batteries from Recycling Perspective towards Circular Economy

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper analyzes the composition of six different types of Li-ion batteries by disassembly and characterization and estimates the potential recovery value of the batteries based on market prices. The reviewers are very confused about whether this paper really solves any scientific problems. The specific questions are as follows:

 

1. What problem does the paper solve? What contribution has it made?

 

2. The article only studies the material composition of six batteries, without considering the differences between individual batteries and more types of batteries (such as prismatic batteries). Can these six batteries represent all Li-ion batteries in the battery market? The author should discuss more.

 

3. Does this paper consider the cost and carbon emissions of battery recycling technology?

 

4. Metals cannot be directly obtained by recycling, and it is meaningless to calculate the potential value of recovery based on metal prices.

 

5. What is the significance of FTIR characterization of diaphragms? How does it affect the conclusions of this paper?

 

Other questions:

 

6. The battery types from He et al. (2015) and Velázquez-Martínez et al. (2019) should be listed in Table 1.

 

7. The calculation method of potential recovery value should be added in the Methods section.

 

8. What is the difference between cylindrical batteries and pouch batteries with the same anode material?

 

9. Regarding battery recycling, lifecycle battery carbon footprint needs to be discussed. -Lifecycle battery carbon footprint analysis for battery sustainability with energy digitalization and artificial intelligence  -An electricity-driven mobility circular economy with lifecycle carbon footprints for climate-adaptive carbon neutrality transformation  -Advanced cycling ageing-driven circular economy with E-mobility-based energy sharing and lithium battery cascade utilisation in a district community

Comments on the Quality of English Language

Revision

Author Response

See document attached.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper present a detetailed characterization of different lithium-ion batteries (pouch and cylindrical) after discharging and dismatling them. It also presents a study from the economic point of view based on the prices of the materials and the chemical composition to serve as indicative to whether is convinient their recycling.

Comment #1

The graphs and tables should be improved. Some suggestions are as follows:

Regarding Figure 4, the levels a) and b) could be embedded directly in the image.

Regarding, Table 1 and Table 2, the headers can be deleted since they are already mentioned in the title. In which case the units can be included also in the title.

- Table 3. The text 'Separator material' can be deleted. In which case, the title can be replace by 'Comparison between the materials of the separators in pouch and cylindrical cells.'

- Figure 9. The graphs can be further processed, for example, by stacking them according to the type of battery . In addition, the formulae LiNiCoAlO2, LiNiMnCoO2 are not balance then I suggest to used the suffixes x, y and z. Furtermore, the PDF number should be included either in the graphs or in the body of the text.

- Figure 12 and 13. I suggest using a column graph for better, identifing the component with colors, each column representing one battery and within the column include the % of each component. Thus, the graph can be reduced from 6 to 3.

 

Comment #2

Line 80 and 81. Please, include the references for what was previously studied regarding LIBs characterization.

Comment #3

Line 102. Regarding the evaporation, I suggest to include further details about the process of evaporation apart from the temperature and how do you assure the all the organic solvent is evaporated.

Comment #4

Line 142. Please include the lamp used for the XRD measurements.

Comment #5

The Final price values from Table 4 what stand for? They are not mentioned in the body of the text.

Comment #6

In the preliminary economic evaluation, the total sum of the prices of the materials multiplied by their percentage in the battery is considered as the battery value but this it is not strictily true since the value of the battery depends on various other factor like assembling. Then, I suggest to change the term battery value for other suitable term so as to avoid to confuse the reader.

Comments on the Quality of English Language

Various changes are proposed to improve the quality of the English language:

- Line 2. You should eliminate the word 'the'

- Lines 45 and 46. You should replace 'to separating' for 'to separate'.

- Line 71 and 72. You should replace '...by polyvinylidene fluoride (PVDF), and one same battery cell also' by '...by polyvinylidene fluoride (PVDF). Also, a cell'

- Line 72 and 73. Paraphrase considering that the electrolyte includes LiPF6 dissolved in an organic solvent.

- Line 87. You should replace 'open' by 'opened'

- Line 102 and 103. Did you mean organic electrolyte? Take into account that the solvent from the electrolyte is evaporated.

- Line 109 and 110. It is confusing for the reader. Are you trying to say that the same batteries used in a previous work by the authors were used in this study? For example, are you presenting a new characterization? It would be helpful to clarify this in the body of the text.

- Line 132. You should replace 'Masses from each active material was...' by 'Active material sample were...' 

- Line 161. You should replace 'techniques can make' by 'techniques that can make'

- Line 162. You should replace 'most all materials' by 'most of the materials'

- Line 184 and 185. The following is improved version of the image caption: Battery discharge by connecting the electrodes with a resistance wire: a) a pouch cell and b) a cylindrical cell

- Line 193. You should replace 'Pouch batteries dismantled, and their...' by 'Dismantled pouch batteries and their...'

- Line 218. In the text 'the Table 1' you should deleted the article 'the'

- Line 222 and 223. You should replace 'to the pouch batteries’ ones;...' by 'those of the pouch batteries;...'

- Line 231 and 232. You should replace 'the weight percentages for the electrodes are consequently lower in the authors’ works, ...' by 'the weight percentages for the electrodes reported in the literature are consequently lower than those determined in the present study, ...'

- Line 234. You should replace 'Masses of the batteries’ components' by 'Mass of each battery component (g)'

- Line 257. You should replace 'identified' by 'of'

- Line 260. You should replace 'recycle' by 'recycling'

- Line 263. You should add 'the' after the word 'in'

- Line from 274 to 283.  Please avoid repetition. The names of the materials should be introduced in the material section in line 25 once.

- Line 313. Please delete the word 'are'

- Line 313 and 314. The text 'These batteries have high energy density since cobalt is easy to manufacture,...' make no sense. Please parapharse.

- Line 319. You should replace 'whic makes' by 'making it'

- Line 336. You should add the article 'the' before 'electrical conductivity'

- Line 338. You should replace 'presented' by 'present'

- Line 340. You should replace 'occur' by 'originate from'

- Line 357. You should eliminate 'for'

- Lines 366 and 367. You should replace 'its market will only increase in the coming years with lower amount of cobalt' by 'NMC battery market will continue to increase in the coming years, specially those with lower amount of cobalt'

- Line 406. It appear that 'de' is a misspeling of 'be'

- Line 426. It appears that 'during' is a more suitable word compared to 'for'

- Lines 429 and 430. You should replace 'In the case of P1, a NMC 442 cathode battery has a value of...' by 'In the case of the P1 battery, which has a cathode of NMC 442, its value is...'

- Line 506. Please replace 'is' by 'occurs'

- Line 530. Please revise.

- Line 541. It appears that 'from' is more suitable than 'in'

- Line 542. You should replace 'material' by 'materials' 

Author Response

See document attached.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The article analyzes six types of batteries but does not present any new findings. I have concerns about some of the results and require further clarification from the author.

1, Please check the manuscript carefully. Some tables and figures do not correspond to the text. For example, in line 410, it says, "From the values ​​shown in Figure 4 and the market prices..."

2, The product prices in Table 5 need references or sources. I have doubts about the price of graphite listed at 28,800 USD/t, which seems too high. This leads to an unreasonable proportion of graphite in the total cost in the subsequent analysis (Figure 13).

3, In Table 5, both P2 and C3 are LFP, and the distribution of each element is similar. However, the price difference is nearly four times, which is questionable.

4, In Figure 12, O is missing in C3.

5, Analyzing every CELL in the actual recycling process is impractical. It would be more meaningful to indicate its composition during production to ensure traceability for recycling. How does the author address this?

6, In Figure 13, as mentioned above, the proportion of graphite is clearly unreasonable.

7, In the conclusions, the statement "The cathode is the most valuable component in the LIBs" is true but is not supported by your results.

Author Response

See document attached.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Since my comments have been well-addressed, this manuscript can be accepted.