Mechanistic Understanding of the Underlying Energy Storage Mechanism of α-MnO2-based Pseudo-Supercapacitors

Mechanistic Understanding of the Underlying Energy Storage Mechanism of α-MnO2-based Pseudo-Supercapacitors

© 2024 Wiley‐VCH GmbH.

Bibliographische Detailangaben
Veröffentlicht in:Advanced materials (Deerfield Beach, Fla.). - 1998. - 36(2024), 46 vom: 15. Nov., Seite e2408476
1. Verfasser: Deng, Lei (VerfasserIn)
Weitere Verfasser: Wang, Zaifa, Cui, Hantao, Guo, Yunna, Ye, Zhangran, Li, Hui, Zhang, Xinyu, Jia, Peng, Zhang, Qiaobao, Zhang, Liqiang
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2024
Zugriff auf das übergeordnete Werk:Advanced materials (Deerfield Beach, Fla.)
Schlagworte:Journal Article EMIMOTF in situ transmission electron microscope microscopic mechanism pseudo‐capacitance mechanism α‐MnO2 nanowires
Beschreibung
Zusammenfassung:© 2024 Wiley‐VCH GmbH.
Manganese dioxide (α-MnO2) has attracted significant research interest in supercapacitors recently. However, the reaction mechanism of α-MnO2 in supercapacitors remains unclear. Therefore, a nano-supercapacitor using Environmental transmission electron microscopy (ETEM) is conducted and investigated the reaction mechanism of α-MnO2 based on three ionic liquids (ILs). It found that in the aprotic ionic liquid (AIL) 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMIMOTF), α-MnO2 nanowires (NWs) undergo an oxidation reaction due to the presence of an active proton at the second position (H2) of the imidazole ring. As a result, α-MnO2 NWs undergo a phase transition and transform into Mn3O4, exhibiting pseudo-capacitive properties. Furthermore, characterization of the macroscopic α-MnO2 electrodes after cycling reveals that after the initial charging cycles, the dominant energy storage mechanism of the supercapacitor transitions from pseudo-capacitance to a dual-layer capacitance formed by the combination of Mn3O4 and unreacted α-MnO2. Simultaneously, due to the coexistence of these two energy storage mechanisms, the specific capacitance of the supercapacitor in EMIMOTF electrolyte reaches up to 80 F g-1, and the cycle number reaches as high as 1000 cycles. The results are expected to provide insights into the selection of electrolytes in supercapacitors and offer a fundamental understanding of the internal reaction mechanisms in capacitors
Beschreibung:Date Revised 15.11.2024
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1521-4095
DOI:10.1002/adma.202408476