Details

Autor(en) / Beteiligte

• Jeong, Gyeong Seok
• Jung, Ku Hyun
• Choi, Siku
• Kim, Ki Chul

Titel

Electrochemical Characteristics of Cyanoquinones as Organic Cathodes for High-Potential Sodium-Ion Batteries

Ist Teil von

• ACS sustainable chemistry & engineering, 2020-08, Vol.8 (30), p.11328-11336

Ort / Verlag

American Chemical Society

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Despite the potential of incorporating electron-withdrawing cyano functional groups in organic cathode materials for sodium-ion batteries, a systematic understanding of the effect of the functionality on the redox properties and electrochemical performance is still limited to be explored. Herein, the electrochemical performance parameters as well as the Na-involved electrochemical redox characteristics for a series of chloranil derivatives with one to four cyano functional group(s) are explored using the computational modeling approach to assess their potential as organic cathode materials. It is highlighted from this study that the incorporation of cyano functional groups would improve both the redox potential and theoretical charge capacity, exhibiting the highest open-circuit redox potential (4.16 V vs Na/Na+) and theoretical charge capacity (386.5 mAh/g) for the chloranil derivative with four cyano functional groups. To be noted, the resulting values are comparable to those for top-ranking organic cathode materials in sodium-ion batteries. It is further verified that the beneficial effect of the cyano functional group on both the redox potential and theoretical charge capacity would lead to its positive impact on the theoretical energy density. These indicate that all the three parameters, namely, redox potential, charge capacity, and energy density, would be improved with the number of cyano functional groups. Further investigation reveals that the redox properties of chloranil derivatives would be strongly correlated with their electronic properties and solvation as well as their structural variations. Notably, the redox activity of a chloranil would be continuously weakened by the gradual change in electron affinity during the discharging process but a drastic increase in solvation would be a critical factor causing its cathodic deactivation. All the findings would assist us to establish a design approach for promising organic cathode materials in sodium-ion batteries.