Oxygen Vacancy-Rich Ultrathin Co3O4 Nanosheets as Nanofillers in Solid-Polymer Electrolyte for High-Performance Lithium Metal Batteries
, Shi Xue Dou 2 and Jiantie Xu 1,3,*
Round 1
Reviewer 1 Report
The authors report a solid composite polymer electrolyte modified by oxygen vacancy-rich Co3O4 nanosheets for lithium metal battery by self-assembly method. The prepared PEO/Co3O4-y-2 showed reduced crystallinity due to the introduction of Co3O4 and achieved a high ionic conductivity of 4.9
10-5 S cm-1. Additionally, PEO/Co3O4-y-2 exhibited high lithium ion transference number of 0.51 and wide electrochemical window of 4.6 V. The topic is highly interesting and fits within the scope of the journal. Therefore, it is worth recommending the review for publication after minor revision.
1. As being highlight of this manuscript, authors should further explain and summarize the advantages of introducing oxygen vacancy into the Co3O4 nanosheets.
2. In composite electrolytes preparation section, authors should introduce the reasons or merits of adding PVP. Furthermore, the constitutional proportion of composite electrolytes should also be discussed.
3. On the stress-stain curves, the physical behaviors before fracture should be better described, including 2 descent stages and yield behavior.
4. On the illustration of PEO/Co3O4-y in Figure 1a, why did the PEO/Co3O4-y show 3 dispersive parts instead of an entirety?
5. How does this work represent a step forward in the field? Authors need to compare obtained electrochemical performance with previous reported composite polymer electrolytes.
6. Some related references could be included in the manuscript for wide readerships (e.g. Energy Material Advances, 2022, Article ID 9753506).
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
In this manuscript, the authors report an interesting design of polymer-based solid electrolyte, in which a conductive Co3O4 was introduced into the substrate. The solid polymer electrolyte (SPE) shows an acceptable performance, but some details need to be confirmed further.
1. How to explain the effect of a conductive filler in an insulative substrate that applied as a solid electrolyte. Will the electronic conductor cause short-cut?
2.The 2D Co3O4-y nanosheets shown in Fig. 1b-d exhibit a flower-like morphology. However, it changes to nanosheets that distributed in the SPE. What is the reason for the morphology change after mixing with PEO. Furthermore, the characterization of vertical diffusion channels is insufficient.
3. The SPE named PEO/Co3O4, but PVP was added according to the Experimental section. The author should explain the role of PVP, or clarify the material of SPE.
4. The analysis of TGA about different weight loss and the final residual should be clarified.
5. According to the DSC tests, the Tm of SPEs are all lower than 70 oC, how to maintain the mechanical strength and dimensional stability at operating temperature (80 oC)?
6. The circuit diagrams for EIS fitting of both conic conductivity and chronoamperometry tests are missing.
7. How to explain the overcharging and a low CE value of cells tested at 0.1 C？
8. Some mistakes appear in some Figures. For example, in Fig. 5b, the sample should be PEO/Co3O4-y-2, rather than PEO/Co3O4-x-0.1. Mpa should be MPa. In Fig.4b, the ionic conductivity should be σ, rather than s.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
In this manuscript, the authors synthesized a series of 2D oxygen vacancy-rich Co3O4-y-x (x = 1, 2 and 3) with well-defined 2D nanostructures, high surface area and controllable vacancy concentrations (Co3O4-y) via a facile self-assembly method and measured the energy storage applications. The manuscript is suggested to be accepted after the following issues are addressed.
1) The authors should add more details related to the XRD such as crystalline size, crystal structure etc.
2) The authors should calculate the pore size and volume from the BET measurement.
3) The Nyquist plot should be amplified at a high-frequency region in order to see the semicircle. Moreover, the X-axis and Y-axis range for the Nyquist curve should be kept the same.
4) What’s about the stability of the device?
5) The authors should add a comparative table or figure to enhance the novelty of the work
6) Many spelling and formatting typos in this paper and the authors should check and revise them thoroughly. So, the language should be polished thoroughly.
7) The authors should revise the manuscript and conclusion to increase the novelty of the work.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Thanks for the authors’ reply, this design is interesting, and looking forward to your following research.
Reviewer 3 Report
Accept in present form.
