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Unveiling the Intricate Intercalation Mechanism in Manganese Sesquioxide as Positive Electrode in Aqueous Zn‐Metal Battery
Author(s) -
Ma Yuan,
Ma Yanjiao,
Diemant Thomas,
Cao Kecheng,
Liu Xu,
Kaiser Ute,
Behm R. Jürgen,
Varzi Alberto,
Passerini Stefano
Publication year - 2021
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.202100962
Subject(s) - sesquioxide , bixbyite , materials science , electrolyte , manganese , intercalation (chemistry) , dissolution , inorganic chemistry , aqueous solution , mesoporous material , electrode , oxide , chemical engineering , chemistry , metallurgy , catalysis , biochemistry , engineering
In the family of Zn/manganese oxide batteries with mild aqueous electrolytes, cubic α‐Mn 2 O 3 with bixbyite structure is rarely considered, because of the lack of the tunnel and/or layered structure that are usually believed to be indispensable for the incorporation of Zn ions. In this work, the charge storage mechanism of α‐Mn 2 O 3 is systematically and comprehensively investigated. It is demonstrated that the electrochemically induced irreversible phase transition from α‐Mn 2 O 3 to layered‐typed L‐Zn x MnO 2 , coupled with the dissolution of Mn 2+ and OH − into the electrolyte, allows for the subsequent reversible de‐/intercalation of Zn 2+ . Moreover, it is proven that α‐Mn 2 O 3 is not a host for H + . Instead, the MnO 2 formed from L‐Zn x MnO 2 and the Mn 2+ in the electrolyte upon the initial charge is the host for H + . Based on this electrode mechanism, combined with fabricating hierarchically structured mesoporous α‐Mn 2 O 3 microrod array material, an unprecedented rate capability with 103 mAh g −1 at 5.0 A g −1 as well as an appealing stability of 2000 cycles (at 2.0 A g −1 ) with a capacity decay of only ≈0.009% per‐cycle are obtained.