期刊論文
| 學年 | 113 |
|---|---|
| 學期 | 1 |
| 出版（發表）日期 | 2025-01-23 |
| 作品名稱 | Revisiting the Electronic Structure of α-MnO2 for Energy Storage Application |
| 作品名稱（其他語言） | |
| 著者 | Priyanka L. Yadav; Pawan Joshi; Vaibhav C. Lokhande; Chi-Feng Lee; Shang-Hsien Hsieh; Hsiao-Tsu Wang; Yu-Cheng Shao; Chih-Wen Pao; Chia-Hao Chen; Jyotiprakash B. Yadav; Madhav Prasad Ghimire; Nishad G. Deshpande; Rahul B. Patil |
| 單位 | |
| 出版者 | |
| 著錄名稱、卷期、頁數 | The Journal of Physical Chemistry C 129(5), p.2619-2629 |
| 摘要 | Herein, we report combined experimental and theoretical electronic structure analyses of cryptomelane-type α-MnO2 with K intercalation to identify the ground-state electronic structure of the electrode for electrochemical energy storage application. Intercalation of K into the tunnels of α-MnO2 provides enhancement in the lattice constants and dense agglomerated microstructure, which was observed from X-ray diffraction and scanning electron microscopy analysis, respectively. Mn3+ and Mn4+ mixed valence states are observed in the electrodes, which mediate the redox reaction observed from the in-operando Mn K-edge XANES and XAFS measurements. Oxygen vacancies are introduced in the electrode material with K intercalation, which align the valence band and conduction band to increase the band gap energy (Eg) of the electrode. The density of states calculation using generalized gradient approximation (GGA) suggest that the Mn 3d, O 2p, and K 4s dominant spectral weight spread below the Fermi level from 2.0 to 8.0 eV, 2.5 to 8.0 eV, and 0.5 to 6.0 eV, respectively. A detailed comparison of the calculated density of states and measured valence band suggest that the Mn 3d - K 4s hybridization-induced mid-gap states appeared across the band gap and associated with charge-switching state, which accelerate the electrochemical redox reaction. Electrochemical performance is therefore improved with K intercalation into the tunnels of α-MnO2, suggesting that the mid-gap-induced charge-switching state promotes the redox reaction. |
| 關鍵字 | |
| 語言 | en_US |
| ISSN | 1932-7447; 1932-7455 |
| 期刊性質 | 國外 |
| 收錄於 | SCI |
| 產學合作 | |
| 通訊作者 | |
| 審稿制度 | 否 |
| 國別 | USA |
| 公開徵稿 | |
| 出版型式 | ,電子版,紙本 |
| 相關連結 |
機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/129450 ) |