TY - JOUR
T1 - Phosphonium plastic crystal salt alloyed with a sodium salt as a solid-state electrolyte for sodium devices
T2 - phase behaviour and electrochemical performance
AU - Makhlooghiazad, Faezeh
AU - Howlett, Patrick C
AU - Wang, Xiaoen
AU - Hilder, Matthias
AU - Macfarlane, Douglas R
AU - Armand, Michel
AU - Forsyth, Maria
PY - 2017
Y1 - 2017
N2 - Mixtures of triisobutylmethylphosphonium bis(fluorosulfonyl)imide (P1i444FSI) with different concentrations of NaFSI display composition-dependent phase behaviour with depression of the melting point upon NaFSI addition and suppression of crystallisation in the middle of the phase diagram and a higher-melting-point, NaFSI-rich mixed-phase region at compositions beyond 60 mol% NaFSI. Thermal treatment of the intermediate compositions results in complete crystallisation of the materials. All compositions showed high ionic conductivity (>10-5 S cm-1) at 20 °C, and Na symmetric cells containing high concentration of NaFSI (Na|[Na0.9(P1i444)0.1]FSI|Na) were cycled efficiently at 50 and 90 °C at 0.05 and 0.1 mA cm-2, respectively. Intermediate composition (Na|[Na0.6(P1i444)0.4]FSI|Na) cells were cycled at room temperature and 50 °C at 0.25 mA cm-2 with very low and stable cell polarisation (200 mV).
AB - Mixtures of triisobutylmethylphosphonium bis(fluorosulfonyl)imide (P1i444FSI) with different concentrations of NaFSI display composition-dependent phase behaviour with depression of the melting point upon NaFSI addition and suppression of crystallisation in the middle of the phase diagram and a higher-melting-point, NaFSI-rich mixed-phase region at compositions beyond 60 mol% NaFSI. Thermal treatment of the intermediate compositions results in complete crystallisation of the materials. All compositions showed high ionic conductivity (>10-5 S cm-1) at 20 °C, and Na symmetric cells containing high concentration of NaFSI (Na|[Na0.9(P1i444)0.1]FSI|Na) were cycled efficiently at 50 and 90 °C at 0.05 and 0.1 mA cm-2, respectively. Intermediate composition (Na|[Na0.6(P1i444)0.4]FSI|Na) cells were cycled at room temperature and 50 °C at 0.25 mA cm-2 with very low and stable cell polarisation (200 mV).
UR - http://www.scopus.com/inward/record.url?scp=85016147809&partnerID=8YFLogxK
U2 - 10.1039/c6ta10340e
DO - 10.1039/c6ta10340e
M3 - Article
AN - SCOPUS:85016147809
VL - 5
SP - 5770
EP - 5780
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
SN - 2050-7488
IS - 12
ER -