Electrochemical Properties of LaMO₃(M=Cr, Mn, and Co) Perovskite Materials

Round 1

Reviewer 1 Report

The article submitted for review „ Electrochemical properties of LaBO₃ (B=Cr, Mn, and Co)
perovskite materials” is the original solution to the problem, which has been presented by the authors of the manuscript. The search for efficient supercapacitors is becoming a challenge for both scientific institutions and industry. The issue raised in the manuscript is very important and requires a lot of time-consuming research.         

The text is written in good, scientific language. It has minor errors, which in no way detract from the work. Listed below are those aspects that need attention and improvement:

Page 2, line 84

It is: …, Manganese chloride tetrahydrate MnCl₂·4H₂O (≥99%), Cobalt nitrate hexahydrate Co(NO₃)₂·6H₂O (≥98.5%) placed in a beaker containing 30 ml in order according to a certain molar ratio, and stirred on a magnetic stirrer for 24 h to obtain a transparent solution.

Should be: …, Manganese chloride tetrahydrate MnCl₂×4H₂O (≥99%), Cobalt nitrate hexahydrate Co(NO₃)₂×6H2O (≥98.5%) were placed in a beaker of volume 30 ml in order to stirr the substance (for 24 h) and obtain transparent solution of certain molar ratio.

Page 2, line 89

It is: …Muffle…

Should be: …muffle…

Page 8

Equation (8) – please mark the multiplication in the formula.

I suggest using full stop after quotation, so (for example):

It is: characteristics.[1,2]

Should be: characteristics [1,2].

The results obtained are original and very important for cognitive and applications aim.
I recommend the paper for publication after the minor corrections will be made.

Page 2, line 84

It is: …, Manganese chloride tetrahydrate MnCl₂·4H₂O (≥99%), Cobalt nitrate hexahydrate Co(NO₃)₂·6H₂O (≥98.5%) placed in a beaker containing 30 ml in order according to a certain molar ratio, and stirred on a magnetic stirrer for 24 h to obtain a transparent solution.

Should be: …, Manganese chloride tetrahydrate MnCl₂×4H₂O (≥99%), Cobalt nitrate hexahydrate Co(NO₃)₂×6H2O (≥98.5%) were placed in a beaker of volume 30 ml in order to stirr the substance (for 24 h) and obtain transparent solution of certain molar ratio.

Page 2, line 89

It is: …Muffle…

Should be: …muffle…

Author Response

Responses letter

Reviewer #1:

The article submitted for review „ Electrochemical properties of LaBO₃ (B=Cr, Mn, and Co) perovskite materials” is the original solution to the problem, which has been presented by the authors of the manuscript. The search for efficient supercapacitors is becoming a challenge for both scientific institutions and industry. The issue raised in the manuscript is very important and requires a lot of time-consuming research. The text is written in good, scientific language. It has minor errors, which in no way detract from the work. Listed below are those aspects that need attention and improvement:

Firstly, we’d like to thank you for your review time and positive comments to our draft. Your comments are quite constructive and useful for revising/refining our draft further. At what follows, we addressed your comments one-by-one. And accordingly we revised the whole draft. The corresponding revises at the new draft have been highlighted by red color.

• It is: …, Manganese chloride tetrahydrate MnCl₂4H2O (≥99%), Cobalt nitrate hexahydrate Co(NO3)2·6H2O (≥98.5%) placed in a beaker containing 30 ml in order according to a certain molar ratio, and stirred on a magnetic stirrer for 24 h to obtain a transparent solution.

Should be: …, Manganese chloride tetrahydrate MnCl2×4H2O (≥99%), Cobalt nitrate hexahydrate Co(NO3)2×6H2O (≥98.5%) were placed in a beaker of volume 30 ml in order to stirr the substance (for 24 h) and obtain transparent solution of certain molar ratio.

Reply: Really thank you for your review time and positive comments to our draft. According to your suggestions, we have made corresponding changes in the new draft.

Page 2, line 89

• It is: …Muffle…Should be: …muffle…

Reply: According to your suggestions, we have made corresponding changes in the in the Revised-manuscript.

• Page 8

Equation (8) – please mark the multiplication in the formula.

I suggest using full stop after quotation, so (for example):

Reply: Thank you for your nice suggestion, we have marked the multiplication in the formula.

• It is: characteristics.[1,2], Should be: characteristics [1,2].

Reply: Thank you for your nice suggestion. We have made corresponding changes in the revised-manuscript.

In short, we wish above elucidations make our draft more solid and transparent. And we wish our new effort do address your comments on this draft.

Thank you again!

Yours sincerely,

Dr. Lei Wang and Song-Tao Dong

Reviewer 2 Report

The paper entitled: Electrochemical properties of LaBO3(B=Cr, Mn, and Co) perovskite materials describes the possible application of lanthanide perovskite oxides as electrode materials for supercapacitors. These materials have excellent properties: electrical conductivity, low cost, and excellent thermal stability. In the present work, LaBO3(B=Cr, Mn, and Co) nanoparticles were prepared by the sol-gel method followed by a calcination route. The obtained samples were analyzed by various techniques such as: X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), Brunauer-Emmett-Teller (BET) surface area measurements, cyclic voltammetry (CV), impedance spectroscopy and galvanostatic charge/discharge (GCD) cycling to characterize their microstructures, morphologies, and electrochemical properties. The acquired results shown that the LaCoO3 nanoparticles exhibited a maximum specific capacitance of 118.4 F/g at a current density of 1 A/g and a low charge transfer resistance of 2.56 Ω in 3 M KOH aqueous electrolyte solutions. The authors affirm that the LaCoO3 based electrode shows greater capacitance behavior due to its larger specific surface area, lower charge transfer resistance, and higher concentration of oxygen vacancy.

Moreover, the following must be revised:

1.      The presented materials were studied from 1979 (https://doi.org/10.1016/0025-5408(79)90048-5). The novelty and advantages of the proposed work have to be clearly stated.

2.      The impedance spectroscopy technique should be included in the abstract.

3.      Phrases as ‘The AC impedance diagram is typically categorized into a high−frequency region and a low−frequency region.’ are not necessary for such paper (such evidence are well known). The authors should check carefully all the paper and eliminate such phrases.

4.      The authors should represent the correlation of the Nyquist plots (figure 5) - of various modified electrodes in electrolyte solution, with the proposed electrical circuit. Thus, the electric parameters of the electric circuit can be obtained (with the standard deviation values), and then should be compared for all electrodes. Moreover, the Chi^2 value give the information about the correct choose electric circuit. A table should be introduced here for all Rct, Rs, C, W, Chi^2 obtained values.

5.      The experimental part must be improved with all working parameters, electrolyte solutions, concentrations. In order to be easier for understanding, the experimental parameters should be written in the chapter of each figure (CV, EIS, GCD).

6.      A correlation of the morpho-structural properties with the electrochemical ones must be done. Otherwise there is just an enumeration of some results.

7.      The authors should compare their results with those obtained already (in the literature); argument your results and explain the advantage/disadvantage of their research.

8.      The LaBO3(B=Cr, Mn, and Co) performances must be critically discussed.

9.      The conclusion must be completely after the correlations of the obtained results.

10.   The English should be checked.

For the previous reasons the proposed work cannot be accepted for publication; after paper reorganization, the manuscript could be considered for publication.

Minor editing of English language required

Author Response

Responses letter

Reviewer #2:

The paper entitled: Electrochemical properties of LaBO3(B=Cr, Mn, and Co) perovskite materials describes the possible application of lanthanide perovskite oxides as electrode materials for supercapacitors. These materials have excellent properties: electrical conductivity, low cost, and excellent thermal stability. In the present work, LaBO3(B=Cr, Mn, and Co) nanoparticles were prepared by the sol-gel method followed by a calcination route. The obtained samples were analyzed by various techniques such as: X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), Brunauer-Emmett-Teller (BET) surface area measurements, cyclic voltammetry (CV), impedance spectroscopy and galvanostatic charge/discharge (GCD) cycling to characterize their microstructures, morphologies, and electrochemical properties. The acquired results shown that the LaCoO3 nanoparticles exhibited a maximum specific capacitance of 118.4 F/g at a current density of 1 A/g and a low charge transfer resistance of 2.56 Ω in 3 M KOH aqueous electrolyte solutions. The authors affirm that the LaCoO3 based electrode shows greater capacitance behavior due to its larger specific surface area, lower charge transfer resistance, and higher concentration of oxygen vacancy.

Firstly, we’d like to thank you for your review time and positive comments to our draft. Your comments are quite constructive and useful for revising/refining our draft further. At what follows, we addressed your comments one-by-one. And accordingly we revised the whole draft. The corresponding revises at the new draft have been highlighted by red color.

1.The presented materials were studied from 1979 (https://doi.org/10.1016/0025-5408(79)90048-5). The novelty and advantages of the proposed work have to be clearly stated.

Reply: Thanks for your comments. Our work focuses on the effects of different B-site elements on the electrochemical properties of lanthanide perovskite oxides. Although the electrochemical properties of LaCrO₃, LaMnO₃ and LaCoO₃ systems as electrode materials for supercapacitors have been reported at present, few literature reports have compared the three systems together to study the reasons. Therefore, we use the same preparation method to study the reasons for the difference in electrochemical properties. We have added the novelty and advantages of the proposed work in the Revised-manuscript.

2. The impedance spectroscopy technique should be included in the abstract.

Reply: According to your suggestion, we have added the impedance spectroscopy technique in the abstract.

3. Phrases as ‘The AC impedance diagram is typically categorized into a high−frequency region and a low−frequency region.’ are not necessary for such paper (such evidence are well known). The authors should check carefully all the paper and eliminate such phrases.

Reply: Thank you for your nice suggestion. We have eliminated such phrases in the revised-manuscript.

4. The authors should represent the correlation of the Nyquist plots (figure 5) - of various modified electrodes in electrolyte solution, with the proposed electrical circuit. Thus, the electric parameters of the electric circuit can be obtained (with the standard deviation values), and then should be compared for all electrodes. Moreover, the Chi^2 value give the information about the correct choose electric circuit. A table should be introduced here for all Rct, Rs, C, W, Chi^2 obtained values.

Reply: Thanks for your comments. We have provided a table for all Rct, Rs, C_PE, Z_W, Chi^2 obtained values.

5. The experimental part must be improved with all working parameters, electrolyte solutions, concentrations. In order to be easier for understanding, the experimental parameters should be written in the chapter of each figure (CV, EIS, GCD).

Reply: Thanks for your comments. We have improved with all working parameters, electrolyte solutions, concentrations and written in the chapter of each figure (CV, EIS, GCD).

6. A correlation of the morpho-structural properties with the electrochemical ones must be done. Otherwise there is just an enumeration of some results.

Reply: Thanks for your comments, we have added the correlation of the morpho-structural properties with the electrochemical.

7. The authors should compare their results with those obtained already (in the literature); argument your results and explain the advantage/disadvantage of their research.

Reply: Thanks for your comments. We have compared their results with those obtained already in the literature.

8. The LaBO₃(B=Cr, Mn, and Co) performances must be critically discussed.

Reply: Thanks for your comments. We have discussed about LaBO₃(B=Cr, Mn, and Co) performances.

9. The conclusion must be completely after the correlations of the obtained results.

Reply: Thanks for your comments. We have rephrased the conclusion in the revised-manuscript.

10. The English should be checked.

Reply: Thanks for your comments. We have carefully checked and revised the spelling and grammar mistakes in the manuscript.

In short, we wish above elucidations make our draft more solid and transparent. And we wish our new effort do address your comments on this draft.

Thank you again!

Yours sincerely,

Dr. Lei Wang and Song-Tao Dong

Reviewer 3 Report

1.Introduction is too short, please add properties of selected perovskite material from the literature.

2. In materials section, please draw attractive figure illustrating methodology.

3. Author should add crystallite size, dislocation density and strain in XRD results.

4. Please provide FTIR results in detail.

5. Rephrase conclusion, it should reflect the summary of whole results.

Minor english revisions is required

Author Response

Responses letter

Reviewer #3:

1. Introduction is too short, please add properties of selected perovskite material from the literature.

Reply: According to your suggestion, we have added properties of selected perovskite material from the literature in revised-manuscript.

2. In materials section, please draw attractive figure illustrating methodology.

Reply: According to your suggestion, we have draw attractive figure illustrating methodology.

3. Author should add crystallite size, dislocation density and strain in XRD results.

Reply: Thanks for your comments. We have add crystallite size, dislocation density and strain in XRD results.

4. Please provide FTIR results in detail.

Reply: Thanks for your comments. FTIR spectroscopy can be used to determine the chemical composition of synthesized samples. The peaks in the FTIR spectra acquired for the samples can be used to get important information about the structure and the elements in synthesized samples. In our work, we used XPS to determine the elements and valence states in the LaBO₃(B=Cr, Mn, and Co) samples, which assisted in proving the results of XRD tests. In the revised draft, we have added detailed XPS data.

5. Rephrase conclusion, it should reflect the summary of whole results.

Reply: Thanks for your comments. We have rephrased the conclusion in the revised-manuscript.

6. Minor english revisions is required

Reply: Thanks for your comments. we have carefully checked and revised the spelling and grammar mistakes in the manuscript.

In short, we wish above elucidations make our draft more solid and transparent. And we wish our new effort do address your comments on this draft.

Thank you again!

Yours sincerely,

Dr. Lei Wang and Song-Tao Dong

Round 2

Reviewer 2 Report

The increasing of the manuscript quality is significant now.

Before the final acceptance the authors should correct:

1. the chapter of figure 1: 'Schematic illustration of LaBO3 (B=Cr, Mn, and Co) powders'.

2. the CVs from figure 4 must be not covered by the legend of the figure.

3. Table 4 present the Rct, Rs, CPE, ZW, Chi^2 values obtained from the EIS spectra for LaBO3(B=Cr, Mn and 290 Co) electrodes. All the presented parameters should have the measuring units [SI].

4. All the parameters presented in the entire text should have the measuring units [SI].

Minor editing of English language required.

Author Response

Responses letter

Reviewer #2:

Firstly, we’d like to thank you for your review time and positive comments to our draft. Your comments are quite constructive and useful for revising/refining our draft further. At what follows, we addressed your comments one-by-one. And accordingly we revised the whole draft. The corresponding revises at the new draft have been highlighted by red color.

1. the chapter of figure 1: 'Schematic illustration of LaBO3 (B=Cr, Mn, and Co) powders'.

Reply: According to your suggestion, we have revised the the chapter of figure 1 by 'Schematic illustration for the synthesis steps of the LaBO3 (B=Cr, Mn, and Co) powders'.

2. the CVs from figure 4 must be not covered by the legend of the figure.

Reply: Thank you for your nice suggestion. We have replaced the Figure 4.

3. Table 4 present the Rct, Rs, CPE, ZW, Chi^2 values obtained from the EIS spectra for LaBO3(B=Cr, Mn and Co) electrodes. All the presented parameters should have the measuring units [SI].

Reply: According to your suggestion, we have added the measuring units [SI] of the presented parameters.

4. All the parameters presented in the entire text should have the measuring units [SI].

Reply: According to your suggestion, we have added the measuring units [SI] of the presented parameters.

5. 5. Minor editing of English language required.

Reply: Thanks for your comments. We have carefully checked and edited of English language in the manuscript.

In short, we wish above elucidations make our draft more solid and transparent. And we wish our new effort do address your comments on this draft.

Thank you again!

Yours sincerely,

Dr. Lei Wang and Song-Tao Dong