Hierarchical Porosity and Surface Oxygenation of Carbon-Based Cathodes Enhances Discharge Capacity and Decreases Discharge Overpotential of Potassium–Oxygen Batteries

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this submission(batteries-3002470), authors reported the preparation of hierarchical porosity carbon papers by the thermal pretreatment in air at different pretreatment times of commercially products which is applied as cathode for Potassium-oxygen batteries. It is found that the contained oxygen functional groups, new formed defects and increased surface area has big contribution for the enhancement of electrochemical properties. Some comments are suggested to further improve the quality of this work as below.

1, The introduction section should be more simplification, some paragraphs should be deleted or combined into one/two paragraphs.

2, The abstract should be further prolonged with the new added performance, including the comparisons of different discharge currents, durability and power densities.

3, For Figure 1, the oxygen content should be checked by EDS and mapping.

4, For Fig.2, the curves of pore size distribution should be added.

5, the information of K anode should be further supplied with the thickness and area size.

Comments on the Quality of English Language

Some sentences should polished in the revision.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

This research work investigates the effect of hierarchical porosity and surface oxygenation of thermally treated carbon paper electrodes on the discharge performance of potassium-oxygen batteries, which is a meaningful fundamental study. However, there are some issues that need to be addressed by the authors. After minor revisions, it can be accepted:

1. The electrochemical tests only conducted discharge performance tests, lacking the study of cycling stability and charge behavior. This is insufficient to comprehensively evaluate the battery performance of the materials. It is suggested that the authors supplement relevant data.

2. It is necessary to characterize the wettability between the thermally treated carbon paper electrodes and the electrolyte.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The revised edition is obviously improved for acceptance.