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Revealing the Flexible 1D Primary and Globular Secondary Structures of Sulfur‐Rich Amorphous Transition Metal Polysulfides
Author(s) -
Artemkina Sofya B.,
Enyashin Andrey N.,
Poltarak Anastassiia A.,
Fedorenko Anastasiya D.,
Makarova Anna A.,
Poltarak Pavel A.,
Shin EonJi,
Hwang SeongJu,
Kim SungJin,
Grayfer Ekaterina D.,
Fedorov Vladimir E.
Publication year - 2019
Publication title -
chemnanomat
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.947
H-Index - 32
ISSN - 2199-692X
DOI - 10.1002/cnma.201900526
Subject(s) - polysulfide , sulfur , amorphous solid , chemistry , transition metal , metal , molecular dynamics , density functional theory , crystallography , chemical physics , computational chemistry , organic chemistry , electrode , electrolyte , catalysis
Sulfur‐rich transition metal polysulfides MS 5 (M=Mo, W) are synthesized by a low‐temperature solution method from corresponding carbonyls M(CO) 6 and elemental sulfur. Extensive characterization reveals that all sulfur atoms are assembled into disulfide ligands (S−S) within the structure of the amorphous spherical particles. Their thermodynamic stabilities are estimated for the first time using density functional theory (DFT) calculations, indicating two stable chain models composed either of binuclear [M 2 S 8 ] or trinuclear [M 3 S 12 ] fragments linked through S−S units. Molecular dynamics (MD) DFTB simulation proves that the S−S bridges predetermine the supreme flexibility of the polysulfide chains as primary structures of MS 5 and their globular secondary arrangements. Interestingly, this type of structural organization is reminiscent of that for classical polymers. Thus, the reasons for MS 5 forming exclusively as amorphous phases are uncovered, which may be extended to many other sulfur‐rich polysulfides. The potential of these materials as increased capacity cathodes for lithium‐ion batteries is shown.