Search: WFRF:(Ojwang Dickson O.)
> (2021) >
Aging and Charge Co...
Aging and Charge Compensation Effects of the Rechargeable Aqueous Zinc/Copper Hexacyanoferrate Battery Elucidated Using In Situ X-ray Techniques
-
- Görlin, Mikaela (author)
- Uppsala universitet,Strukturkemi
-
- Ojwang, Dickson O. (author)
- Uppsala universitet,Strukturkemi
-
- Lee, Ming-Tao (author)
- Uppsala universitet,Strukturkemi
-
show more...
-
- Renman, Viktor (author)
- Department of Materials Science and Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
-
- Tai, Cheuk-Wai (author)
- Stockholms universitet,Institutionen för material- och miljökemi (MMK),Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden
-
- Valvo, Mario (author)
- Uppsala universitet,Strukturkemi
-
show less...
-
(creator_code:org_t)
- 2021-12-08
- 2021
- English.
-
In: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 13:50, s. 59962-59974
- Related links:
-
https://doi.org/10.1...
-
show more...
-
https://uu.diva-port... (primary) (Raw object)
-
https://pubs.acs.org...
-
https://urn.kb.se/re...
-
https://doi.org/10.1...
-
https://urn.kb.se/re...
-
show less...
Abstract
Subject headings
Close
- The zinc/copper hexacyanoferrate (Zn/CuHCF) cell has gained attention as an aqueous rechargeable zinc-ion battery (ZIB) owing to its open framework, excellent rate capability, and high safety. However, both the Zn anode and the CuHCF cathode show unavoidable signs of aging during cycling, though the underlying mechanisms have remained somewhat ambiguous. Here, we present an in-depth study of the CuHCF cathode by employing various X-ray spectroscopic techniques. This allows us to distinguish between structure-related aging effects and charge compensation processes associated with electroactive metal centers upon Zn2+ ion insertion/deinsertion. By combining high-angle annular dark-field-scanning electron transmission microscopy, X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy, and elemental analysis, we reconstruct the picture of both the bulk and the surface. First, we identify a set of previously debated X-ray diffraction peaks appearing at early stages of cycling (below 200 cycles) in CuHCF. Our data suggest that these peaks are unrelated to hypothetical ZnxCu1–xHCF phases or to oxidic phases, but are caused by partial intercalation of ZnSO4 into graphitic carbon. We further conclude that Cu is the unstable species during aging, whose dissolution is significant at the surface of the CuHCF particles. This triggers Zn2+ ions to enter newly formed Cu vacancies, in addition to native Fe vacancies already present in the bulk, which causes a reduction of nearby metal sites. This is distinct from the charge compensation process where both the Cu2+/Cu+ and Fe3+/Fe2+ redox couples participate throughout the bulk. By tracking the K-edge fluorescence using operando XAS coupled with cyclic voltammetry, we successfully link the aging effect to the activation of the Fe3+/Fe2+ redox couple as a consequence of Cu dissolution. This explains the progressive increase in the voltage of the charge/discharge plateaus upon repeated cycling. We also find that SO42– anions reversibly insert into CuHCF during charge. Our work clarifies several intriguing structural and redox-mediated aging mechanisms in the CuHCF cathode and pinpoints parameters that correlate with the performance, which will hold importance for the development of future Prussian blue analogue-type cathodes for aqueous rechargeable ZIBs
Subject headings
- NATURVETENSKAP -- Kemi -- Materialkemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Materials Chemistry (hsv//eng)
- TEKNIK OCH TEKNOLOGIER -- Materialteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Materials Engineering (hsv//eng)
Keyword
- Aging effects
- aqueous rechargeable zinc-ion batteries
- charge compensation process
- in situ X-ray absorption spectroscopy
- Prussian blue analogues
- X-ray diffraction
- X-ray photoelectron spectroscopy
- zinc copper hexacyanoferrate
Publication and Content Type
- ref (subject category)
- art (subject category)
Find in a library
To the university's database