TY - JOUR

T1 - The effect of silicon dioxide on the structural, thermal and transport properties of an organic ionic plastic crystal (n-C4H9)4NBF4

AU - Stebnitskii, Ivan

AU - Mateyshina, Yulia

AU - Uvarov, Nikolai

N1 - This work was supported by the Russian Science Foundation (project 20-13-00302), https://www.rscf.ru/en.

PY - 2024

Y1 - 2024

N2 - Composite solid electrolytes based on an organic ionic plastic crystal (nC4H9)4NBF4 with highly dispersed SiO2 with specific surface area of Ss = 324±10 m2/g have been studied for the first time. By methods of X-ray diffraction and differential scanning calorimetry, it was found that the introduction of SiO2 leads to amorphization of the salt. An unusual size effect was observed in the composites: the temperature of the polymorphic transition of the salt shifted from 67 °C to 60 °C, while the melting point did not change. The 0.15(n-C4H9)4NBF4–0.85SiO2 composite was found to possess the highest electrical conductivity (σ = 2∙10–5 S/cm at 150 °C), which is 1.5 orders of magnitude higher than that of the initial salt. Modelling of the concentration dependences of the electrical conductivity of composites using the mixing equation showed that the reason for the increase in electrical conductivity is the formation of an amorphous layer of salt, the electrical conductivity of which is 3 orders of magnitude higher than that of the crystalline phase (n-C4H9)4NBF4. The obtained results can be used for the design of high-performance composites based on organic ionic plastic crystals for application in electrochemical devices.

AB - Composite solid electrolytes based on an organic ionic plastic crystal (nC4H9)4NBF4 with highly dispersed SiO2 with specific surface area of Ss = 324±10 m2/g have been studied for the first time. By methods of X-ray diffraction and differential scanning calorimetry, it was found that the introduction of SiO2 leads to amorphization of the salt. An unusual size effect was observed in the composites: the temperature of the polymorphic transition of the salt shifted from 67 °C to 60 °C, while the melting point did not change. The 0.15(n-C4H9)4NBF4–0.85SiO2 composite was found to possess the highest electrical conductivity (σ = 2∙10–5 S/cm at 150 °C), which is 1.5 orders of magnitude higher than that of the initial salt. Modelling of the concentration dependences of the electrical conductivity of composites using the mixing equation showed that the reason for the increase in electrical conductivity is the formation of an amorphous layer of salt, the electrical conductivity of which is 3 orders of magnitude higher than that of the crystalline phase (n-C4H9)4NBF4. The obtained results can be used for the design of high-performance composites based on organic ionic plastic crystals for application in electrochemical devices.

KW - ionic conductivity

KW - organic ionic plastic crystal

KW - silicon dioxide

KW - solid composite electrolytes

KW - tetrabutylammonium tetrafluoroborate

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85201221962&origin=inward&txGid=0264bfaeaf8034add4987ce630edb2da

UR - https://www.mendeley.com/catalogue/6b1d42eb-5a0f-3e76-8ffb-cbf2c5180062/

U2 - 10.15826/chimtech.2024.11.3.07

DO - 10.15826/chimtech.2024.11.3.07

M3 - Article

VL - 11

JO - Chimica Techno Acta

JF - Chimica Techno Acta

SN - 2409-5613

IS - 3

M1 - 202411307

ER -