Additive Manufacturing as a Means of Gas Sensor Development for Battery Health Monitoring

Round 1

Reviewer 1 Report

The present paper reports on the oxide materials as a chemosensors for the safety purpose in batteries. This is one such interesting study for the energy systems. The paper seems to be quite good. This will be an addition to energy storage research. However, some major points are to be clarified before accepting this manuscript and also need additional experiments to get more insight.

Introduction part should be re written. Readers will have more attentions, once the authors highlight the importance of selecting the semiconducting oxide (CuO and Fe2O3) and Al2O3/CuO and CuO:Fe2O3 for
this study as sensor. Can author comment on how the present study will improve the
performance of battery. Whether this will only for safety or any additional support in battery performance? Author needs to highlight the importance of metal oxide support for
energy systems. Can Author comment on recent published paper by the same group of
higher performance in gas response with the present paper work. Ex:
TiO2/Cu2O/Cu….

ACS Appl. Mater. Interfaces 2021, https://0-doi-org.brum.beds.ac.uk/10.1021/acsami.1c04379

This paper doesn’t have any theoretical study and many other. Does this work will help to metal air battery systems? Comment Compare the present work with the reported method and materials. Comment on the novelty or new findings in this study. The manuscript needs to rewritten by using the suggested reference papers. I strongly recommend the authors to cite the following papers before submitting the revised articles.

Reference Example: Journal of Power Sources 455 (2020) 227972 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

In this work the authors produced two types of gas sensors and tested them to detect vapors of solvents which are commonly used in the Li-ion battery technology. The English language is very good. The introduction gives a comprehensive description of the state of the art, and the manuscript is fluent. The methods section is sufficiently described. Nevertheless, the novelty of these materials is not sufficient and several characterization studies are missing.

Taking all together, my opinion is that this manuscript must be rejected from publication in the Chemosensors journal.

My major concerns are listed here below:

1. Line 103: I wouldn't classify CO₂ as an "inflammable gas".
2. Line 140: What is the reason for this exact temperature (426°C and not 425°C)?
3. Lines 263-264: Raman spectroscopy should detect also amorphous phases. The authors must clarify this point.
4. Line 281: Al, not Zn.
5. Lines 295-301: Samples are tested at a moderate high temperature. Which is the typical temperature expected for leaked gases in a real battery system? Is this temperature coherent with that selected for these tests? If not, the proposed devices are useless for Li-ion technology applications.
6. Line 420: the chemical formula of hafnia is not correct.
7. Line 439: in my opinion “selectivity” is not the most appropriate term, since the sensor cannot distinguish the two gases if contained into a mixture. Here the difference is just in signal intensity.
8. Where is supposed to be placed the proposed sensor? If outside the battery device, this means that gases are coming out because the case of the battery brakes, and this is too late for safety. Indeed, the battery can take fire a few milliseconds after the case brakes. The authors must discuss this point.
9. These sensors are mainly working due to the interaction which are established between the gas and the surface of the device. Thus, understanding the chemical properties of the surface is fundamental and XPS studies must be performed.
10. TEM and HR-TEM images with also Fast Fourier Transformation (FFT) patterns should be collected and discussed, in order to get more information on the structure and inhomogeneities into the samples. For example, this study could explain the location and eventual segregation of Al₂O₃ particles into the material.
11. A possible gas sensing mechanism must be proposed and described, which is the “core” of this study.

Author Response

Dear Reviewer,

Please see the attachment.

With kind regards

Authors

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript describes about chemosensor composed of semiconducting metal oxide nanoparticles made by direct ink writing method. The authors deal with the detection of electrolyte vapors to improve the safety of lithium ion batteries. It is, however, not recommended to be published for following reasons; 1. The authors claimed that it is possible to control and improve the “safety of the battery” by developing gas-detectable chemosensors. Meanwhile, development of chemosensor is closer to prevention rather than improvement or control. The authors should make it clear what they want to suggest with proper experiments and explanations. 2. The most explosive gas generated from repeated charge-discharge cycle of LiB is HF gas, which is formed by side reaction of lithium salt in electrolyte such as LiTFSI or LiPF6. The authors should conduct additional experiment to test selectivity and sensitivity toward HF gas. 3. The authors used Cu-Fe based nanoparticles using 3D-printing method. There should be sufficient explanations of the reasons why they’ve chosen that materials and methodology with related recent studies. There is, however, no reasonable reasons but only ambiguous words like ‘vary’, ‘many’, ‘various’, and ‘large variety’, ‘these configuration’ etc. 4. The title is “Chemosensors based on semiconducting oxide nanostructures for battery safety applications”, I do not think it is a title that comprehensively includes the description. The authors should conduct proper experiments to show application of sensor to prevent from the battery explosion, however, there is insufficient mention of how it can be used exactly. 5. In Introduction and New perspective section, there are too many explanations and references out of the topic. Therefore, it is necessary to organize and concisely compress the contents. 6. The authors should revise the figure 6 and 9b. There is no numbering (a, b, c, and d) and unclear image. Especially Figure 1 does not show sufficient information and does not match well with explanation. If they used 3D-printing method, there must be real image also. 7. Every content of subtitles and conclusions does not match well with title. I’m losing the main topic what the authors want to suggest.

Author Response

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Round 2

Reviewer 1 Report

accepted

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Reviewer 2 Report

The authors successfully answered to all the questions raised during R1. Thus, the manuscript can be accepted in this new version.

Author Response

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Reviewer 3 Report

The manuscript can be accepted as it is.

Author Response

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