Electrochemical Oxidation of Lithium Carbonate Generates Singlet Oxygen.
Angew Chem Int Ed Engl
; 57(19): 5529-5533, 2018 05 04.
Article
en En
| MEDLINE
| ID: mdl-29543372
ABSTRACT
Solid alkali metal carbonates are universal passivation layer components of intercalation battery materials and common side products in metal-O2 batteries, and are believed to form and decompose reversibly in metal-O2 /CO2 cells. In these cathodes, Li2 CO3 decomposes to CO2 when exposed to potentials above 3.8â
V vs. Li/Li+ . However, O2 evolution, as would be expected according to the decomposition reaction 2 Li2 CO3 â4 Li+ +4 e- +2 CO2 +O2 , is not detected. O atoms are thus unaccounted for, which was previously ascribed to unidentified parasitic reactions. Here, we show that highly reactive singlet oxygen (1 O2 ) forms upon oxidizing Li2 CO3 in an aprotic electrolyte and therefore does not evolve as O2 . These results have substantial implications for the long-term cyclability of batteries they underpin the importance of avoiding 1 O2 in metal-O2 batteries, question the possibility of a reversible metal-O2 /CO2 battery based on a carbonate discharge product, and help explain the interfacial reactivity of transition-metal cathodes with residual Li2 CO3 .
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Año:
2018
Tipo del documento:
Article
País de afiliación:
Austria