The effects of vacancies and their mobility on the dynamic heterogeneity in 1,3-dimethylimidazolium hexafluorophosphate organic ionic plastic crystals

Abstract

Organic ionic plastic crystals (OIPCs) are the crystals of electrolytes with a long-range translational order. The rotational modes of ions in OIPCs are, however, activated even in solid phases such...

The accurate estimation of the third virial coefficients for helium using three‐body neural network potentials

“…4 It is, however, a challenging issue to obtain and describe many-body interactions in molecular dynamics (MD) simulations, 5,6 which have been conducted to study thermodynamic and dynamic properties of various systems. [7][8][9][10][11][12][13][14][15][16][17][18] Many-body interactions are often ignored in molecular dynamics simulations due to the difficulty in describing the many-body interactions properly. Recent studies have shown that the neural network potential could be an emerging way to describe many-body interactions.…”

“…For example, a simulation study for water showed that many‐body interactions contribute about 13% of the total interaction energy of the water cluster 4 . It is, however, a challenging issue to obtain and describe many‐body interactions in molecular dynamics (MD) simulations, 5,6 which have been conducted to study thermodynamic and dynamic properties of various systems 7–18 . Many‐body interactions are often ignored in molecular dynamics simulations due to the difficulty in describing the many‐body interactions properly.…”

Solid-state electrolytes for safe rechargeable lithium metal batteries: a strategic view

“…For instance, the ionic conductivity of OIPCs is highly associated with the motional modes of cations, anions, and their correlation to defect formation [e.g. vacancies] during structural rearrangement [34,35]. For this reason, the understanding of the relationship between phase behaviors and ion transport is critical for the design of high-performance OIPC-based electrolytes [36,37].…”

Effects of alkali ion dopants on the transport mechanisms and the thermal stabilities of imidazolium-based organic ionic plastic crystals

“…Organic ionic plastic crystals (OIPCs), in which solid-to-solid phase transitions occur and ions undergo heterogeneous rotational diffusion in crystalline solid phases, are considered excellent candidates for solid-state electrolytes of rechargeable batteries. [4][5][6][7][8][9] The translational and the rotational diffusion of molecular ions in OIPCs are spatially heterogeneous, [10][11][12][13][14][15][16][17][18] which enhances the ionic conductivity while maintaining a crystalline solid state. [19][20][21][22][23][24][25] Previous studies showed that when Li + ions are doped into OIPCs, the transport of both matrix ions and Li + ions in OIPCs was enhanced significantly.…”

“…In order for ions to diffuse within a lattice structure, ions would have to hop between neighbor sites or hop through defects. 11,20,[61][62][63][64][65][66][67][68] Chen et al performed molecular dynamics simulations to investigate the hopping mechanism of doped ions (Na + and Li + ) in diethyl(methyl)(isobutyl)phosphonium hexafluorophosphate ([P 1,2,2,4 ][PF 6 ]) crystals. 68 They showed that Na + ions formed a triangular solvation shell with three neighbor PF 6 À ions, whereas Li + ions formed a tetrahedral solvation shell with four PF 6 À ions.…”