Fast ion conduction in molecular plastic crystals

Phase Behavior of the [N(C₂H₅)₄][BF₄]-[N(C₃H₇)₄][BF₄] Binary System

“…3,12,[15][16][17] During considerable efforts to increase the ionic conductivity of OIPCs, the method of doping of the salts of target ions into OIPCs has been adopted since it was reported to significantly increase the ionic conductivity up to several orders of magnitude. 5,7,9,[18][19][20][21][22][23] Among these materials, [N-ethyl-N-methylpyrrolidinium][N(SO 2 -CF 3 ) 2 ] was one of the OIPCs to exhibit high ionic conductivity, and doping with Li[N(SO 2 CF 3 ) 2 ] salt to this OIPC was found to result in enhancement in ionic conductivity by twenty times and was very attractive for lithium secondary battery application. 5,19,20 Addition of an inorganic salt to OIPCs has been mainly carried out to introduce mobile ions such as Li + to achieve good ion conduction, whereas mixing two OIPCs is also considered as a method to obtain high ionic conductivity, which typically focuses on the change of their structural and thermal properties.…”

Molecular diffusion and dc conductivity perfectly correlated with molecular rotational dynamics in a plastic crystalline electrolyte

“…The disorder in this plastic-crystalline phase is associated with isomeric fluctuations and with large-angle molecular rotations in which the C-C bond orientation jumps from one diagonal position of the cubic cell to another. 13,[18][19][20] Below 233 K, pure SN displays a perfectly crystalline monoclinic phase without molecular motions nor isomerism. 20,21 In spite of the widespread belief that the orientational dynamic processes in plastic SN are beneficial to its ionic mobility, 20,22 no clear correlation has been found between both quantities.…”

“…Upon doping the mixture with LiBF 4 , the dc conductivity increased due to the higher ion density. [13][14][15] The characteristic frequency of the relaxation is lower in the doped mixture (especially at low T) due to the stronger interactions induced by the presence of Li + and BF 4 -ions. 31 Also the dc conductivity values are quite different: not only is σ dc higher when Li + ions are present, but it also spans a larger number of decades between 240 and 160 K (instead, the relaxation frequency spans a smaller number of decades, in a given temperature interval, when Li + ions are present).…”

Effect of Succinonitrile on Electrical, Structural and Thermal Properties of PVA-Based Polymer Electrolyte for Magnesium Battery

“…It has been reported that in the plastic crystalline phase of highly polar SN (succinonitrile), various salts can be dissolved to give solid electrolytes with high ionic conductivities over a wide temperature range [9][10][11]. The presence of plasticity (i.e., easy deformation without fracture under applied stress [12]) in SN and its high degree of polarity provides a novel opportunity to develop composite polymeric systems involving plastic crystal as a solid plasticizer [13].…”