Toward unlocking the Mn^{3+}/Mn^{2+}$ redox pair in alluaudite-type Na_{2+2z}Mn_{2-z}(SO_{4})_{3-x}(SeO_{4})_{x}$ cathodes for sodium-ion batteries
| Autor: | Olesia M. Karakulina, Artem M. Abakumov, An Hardy, Dries De Sloovere, Maria A. Kirsanova, Joke Hadermann, Marlies K. Van Bael |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Chemistry
02 engineering and technology Crystal structure 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Electrochemistry 01 natural sciences Redox 0104 chemical sciences Electronic Optical and Magnetic Materials Inorganic Chemistry Metal Electronegativity Crystallography visual_art Materials Chemistry Ceramics and Composites visual_art.visual_art_medium Physical and Theoretical Chemistry Isostructural 0210 nano-technology Inductive effect Solid solution |
| Zdroj: | Journal of solid state chemistry |
| ISSN: | 0022-4596 |
| Popis: | In polyanion cathodes, the inductive effect alters the potential of a M(n+1)+/Mn+ redox couple (M - transition metal) according to the electronegativity of the X cation in the polyanion groups (XO4m+). To manipulate the operating potential, we synthesized a series of mixed sulfate-selenate alluaudites, with structure formulas Na2+2zMn2-z(SO4)(3-x)(SeO4)(x) and Na2.81Ni1.60(SO4)(1.43)(SeO4)(1.57). Their crystal structure was determined from powder X-ray diffraction data, revealing that the Mn-based alluaudites form solid solutions with the same crystal structure for x = 0.75; 1.125 and 1.5. Na2.81Ni1.60(SO4)(1.43)(SeO4)(1.57) is isostructural to the Mn-based alluaudites. Although the Na2+2zMn2-z(SO4)(3-x)(SeO4)(x) compound with the highest selenium content demonstrates a reversible discharge capacity of 60 mAh g(-1), only a small part of this electrochemical activity can be ascribed to the Mn3+/Mn2+ redox couple. The redox potential of the Mn3+/Mn2+ pair in Na2+2zMn2-z(SO4)(3-)x(SeO4)(x) decreases with increasing values of x, in agreement with the lower electronegativity of Se compared to that of S. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect