Electrochemical Mechanism Underlying Lithium Plating in Batteries: Non-Invasive Detection and Mitigation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors review prospective studies on various hypotheses on coating mechanisms, the influence of environmental and electrochemical conditions on coating, recent developments in electrochemical detection methods, real-time detection potential, and mitigation methods. The advantages and challenges associated with different electrochemical detection and mitigation methods are highlighted. The authors analyse outstanding technical issues and possible future research directions to encourage the development of new ideas and methods to prevent lithium plating. The paper is extensive and includes a large list of references.

1. The application of carbon nanotubes with different structural properties and morphology for electrodes of lithium-ion batteries should be considered [Shchegolkov, A.V., Komarov, F.F., Lipkin, M.S. et al. Synthesis and Study of Cathode Materials Based on Carbon Nanotubes for Lithium-Ion Batteries. Inorg. Mater. Appl. Res. 12, 1281-1287 (2021). https://doi.org/10.1134/S2075113321050373]

2. Tables listing the properties of electrolytes and their influence on the parameters of lithium ion batteries should be added in some sections.

3. Figures are poorly designed.

4. Conclusions are not specific. Numerical data should be given and the best methods to prevent lithium plating should be stated in more detail.

 

 

Comments on the Quality of English Language

The English could be improved to more clearly express the research.

Author Response

1. The application of carbon nanotubes with different structural properties and morphology for electrodes of lithium-ion batteries should be considered [Shchegolkov, A.V., Komarov, F.F., Lipkin, M.S. et al. Synthesis and Study of Cathode Materials Based on Carbon Nanotubes for Lithium-Ion Batteries. Inorg. Mater. Appl. Res. 12, 1281-1287 (2021). https://doi.org/10.1134/S2075113321050373]

 

Ans- Thank you for your review and sharing of this article. Our current manuscript mostly describes the plating process in graphite anode batteries because of their mass use in electric vehicles. For general description, a sub-paragraph has been incorporated into the manuscript considering different types of anodes such as LCO, CNT, and Lithium metal. [Line no 48-55]

2. Tables listing the properties of electrolytes and their influence on the parameters of lithium-ion batteries should be added in some sections.

Ans- Thank you for your review.  A few different electrolytic parameters and their influence on plating deposition due to additive addition have been incorporated into Table 4 under “Additive addition to electrolyte row.” The table also highlighted the effect of different electrolytic parameters and the limitations of this method. [Line no 595-596]

3. Figures are poorly designed.

Ans- All the figures have been updated into the manuscript and high-resolution images are separately attached with the manuscript.

4. Conclusions are not specific. Numerical data should be given, and the best methods to prevent lithium plating should be stated in more detail.

Ans- These methods are yet to be deployed for commercial applications. All of them are currently in lab-scale developmental process. But a bright prospect is available for an internal heating method for a plating-free operation.  The efficacy of these methods has also been discussed in the manuscript. [Line no 757-762]

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have provided a very interesting review on Li-plating behavior for graphite-based anode. This review is comprehensive enough and showed interesting points. Furthermore, it also showed very detailed technical analysis. Therefore, I would suggested a publication in this journal. My comments below are necessarily to change before it officially publishes here. 

1. There is minimal discussion on strategies to prevent dendrite formation. Can the authors suggest design modifications, such as changes in current collectors or electrolytes, to mitigate dendrite growth?

2. Can the authors also provide thermal runaway topics in terms of Li-plating behavior in graphite?

3. There is minimal discussion on strategies to prevent dendrite formation. Can the authors suggest design modifications, such as changes in current collectors or electrolytes, to mitigate dendrite growth?

4. The manuscript discusses reversible and irreversible lithium deposition but lacks clear criteria to differentiate them in practical applications. Can the authors provide more experimental evidence to support the distinction between the two?

Author Response

1. There is minimal discussion on strategies to prevent dendrite formation. Can the authors suggest design modifications, such as changes in current collectors or electrolytes, to mitigate dendrite growth?

Ans: Thank you for your review. This manuscript primarily focuses on the graphitic anode material due to its massive use in electric vehicles. For Graphitic anode material, Cu current collectors are mainly used.  The effect of collector modification is also included in the subsection of the surface engineering. For porous electrode, only liquid electrolytes have been considered. Various liquid electrolyte engineering method have been discussed to eliminate plating deposition and its growth.

In the SEI modification subsection, it has been mentioned that artificially formed SEI on the anode surface can inhibit dendritic deposition. A brief information related to the various current collectors and other types of anodes have also been incorporated into the manuscript. [Line 48-55, 589-594, 576-582, 684-686]

2. Can the authors also provide thermal runaway topics in terms of Li-plating behavior in graphite?

- The thermal runway was also triggered by lithium plating in two ways. Both types are discussed in plating condition areas and highlighted in yellow. [Line no 144-147]

3. There is minimal discussion on strategies to prevent dendrite formation. Can the authors suggest design modifications, such as changes in current collectors or electrolytes, to mitigate dendrite growth?

Ans: Thank you for your review. This manuscript primarily focuses on the graphitic anode material due to its massive use in electric vehicles. For Graphitic anode material, Cu current collectors are mainly used.  The effect of collector modification is also included in the subsection of the surface engineering. For porous electrode, only liquid electrolytes have been considered. Various liquid electrolyte engineering method have been discussed to eliminate plating deposition and its growth.

In the SEI modification subsection, it has been mentioned that artificially formed SEI on the anode surface can inhibit dendritic deposition. A brief information related to the various current collectors and other types of anodes have also been incorporated into the manuscript. [Line 48-55, 589-594, 576-582, 684-686]

4. The manuscript discusses reversible and irreversible lithium deposition but lacks clear criteria to differentiate them in practical applications. Can the authors provide more experimental evidence to support the distinction between the two?

Ans: The paragraph containing reversible and irreversible lithium has been updated with fine language and more evidence. A clear definition including stripping phenomena has also been incorporated into the manuscript. [Line no127-137,144-147]

Reviewer 3 Report

Comments and Suggestions for Authors

The subject is very important: The accumulation of metallic lithium on the graphite anode surface during rapid charging or at low temperatures that limits battery performances.

Author Response

Reply from Author to reviewer The subject is very important: The accumulation of metallic lithium on the graphite anode surface during rapid charging or at low temperatures that limits battery performance.

Ans: Thank you for your review of this manuscript.

Reviewer 4 Report

Comments and Suggestions for Authors

Please address the following comments:

• Thermodynamic and Kinetic Details: Please provide more information on the thermodynamic and kinetic criterial voltage to determine lithium plating happening.
• Line 142: Does the localized internal temperature change refer specifically to the anode electrode?
• Line 155: The summary regarding increased lithium flux is too broad. The increased lithium flux need high enough to trigger voltage criterial leading to lithium plating.
• High-Temperature Lithium Plating: This section could be clarified, as it may be misleading. Typically, temperatures above room temperature are favorable for preventing lithium plating. The evidence in section a.ii appears to relate more to non-uniform temperature distribution than absolute high temperatures.
• Line 166: Could you further elaborate on where heterogeneous electrolyte distribution and how it contributes to lithium plating?
• Line 203: In my view, lithium plating is not a new field but has gained importance recently for enabling fast charging. Aging naturally leads to lithium plating due to increased resistance and induced heterogeneity. Please consider fine-tuning this sentence.
• Line 281: Stress distribution varies between cylindrical and prismatic cells. A stiffer outer edge condition is more typical of prismatic cells than cylindrical cells.
• Additional design factors to trigger Li plating:
• Coating thickness
• Compare cell chemistry, such as graphite and LTO
• Cell sizes, including comparisons between large-format and small cells

Author Response

• Thermodynamic and Kinetic Details: Please provide more information on the thermodynamic and kinetic criteria voltage to determine what lithium plating is happening.

Ans: Thank you for your review. It has been addressed. The thermodynamic and kinetic criteria have been described clearly with more descriptive evidence. [Line no 157-165]

 

• Line 142: Does the localized internal temperature change refer specifically to the anode electrode?

Ans: For plating initiation, the significant effect comes from the local equilibrium potential change of the anode surface. But Cathode temperature also has an effect; the work done by Carter et al. also highlighted the evidence of plating when the cathode has a higher temperature than the anode. Both observations have been discussed in the manuscript. [Line no 271-274, 277-280]

 

• Line 155: The summary regarding increased lithium flux is too broad. The increased lithium flux needs to be high enough to trigger voltage criteria leading to lithium plating.

Ans: The sentence has been concise and modified. [Line no 157-161]

 

• High-Temperature Lithium Plating: This section could be clarified, as it may be misleading. Typically, temperatures above room temperature are favorable for preventing lithium plating. The evidence in section a.ii appears to relate more to non-uniform temperature distribution than absolute high temperatures.

Ans: The subheading has been updated as “Non uniform temperature gradient” considering the topic describe in the section. [Line 270]

• Line 166: Could you elaborate on where heterogeneous electrolyte distribution is and how it contributes to lithium plating?
• Ans: This has been highlighted in the manufacturing and local defect section. It has been observed that localized drying out of electrolytes or leakage of the electrolyte creates some void area of the electrode that is inaccessible for lithium ion. This increases the surrounding Li⁺ flux of the empty area, making a favorable condition for lithium plating. [Line no 217-220]

 

• Line 203: In my view, lithium plating is not a new field but has gained importance recently for enabling fast charging. Aging naturally leads to lithium plating due to increased resistance and induced heterogeneity. Please consider fine-tuning this sentence.

Ans: The subsection aging Condition has been modified. The paragraph related to plating during long-term cycling has been fine-tuned and elaborated. [Line no 229-245]

•  
• Line 281: Stress distribution varies between cylindrical and prismatic cells. A stiffer outer edge condition is more typical of prismatic cells than cylindrical cells.
• Ans: The paragraph corresponding stress on the different type cells has been corrected. Cylindrical cell has higher stress than prismatic cells. The effect of pressure on cylindrical cell, pouch cell and coin cell has been discussed. [Line no 300-307,313-315]

 

• Additional design factors to trigger Li plating:

• Coating thickness

Ans: The thicker coating is susceptible to lithium plating earlier than the thinner coating. Previous literature suggests that lower particle size and thinner anode thickness decrease the plating tendency of the graphite electrode. [Line 659-660]

• Compare cell chemistry, such as graphite and LTO

Ans: A brief comparison between the cell chemistry of anode has also been incorporated into the manuscript. [Line no 48-55]

• Cell sizes, including comparisons between large-format and small-cells

Ans: The effect of different cell sizes and shapes, such as coin cells, pouch cells, and cylindrical cells, has also been incorporated into the manuscript. [Line No 300-307,313-315]

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have made the necessary corrections. This applies to all sections. Methodology and experiment. The article can be recommended for publication.