The Development of Organic Ionic Plastic Crystals As Solid State Electrolytes for Energy Storage
Understanding the ion transport behaviour of OIPCs, both in their pure and doped state (i.e. in the presence of a small amount of a lithium salt, to enable their use in lithium batteries), is crucial for their development as solid electrolytes.
Here we present our investigations into the ion transport mechanism in these materials using both experimental data (single crystal XRD, multinuclear solid-state NMR, DSC, ionic conductivity and SEM) and theoretical techniques (molecular dynamics and second moment-based solid static NMR line width simulations).
We also discuss the physical properties and application of the OIPC triisobutyl(methyl)phosphonium bis(fluorosulfonyl)imide (P1444FSI) doped with 4 mol% LiFSI. The good conductivity of this material (0.26 mS cm-1 at 22 °C) enables cycling of lithium cells (Li|LiFePO4) at room temperature, achieving about 160 mA h g-1 discharge capacity at 20 oC, which is the highest for OIPC based cells to date.
 J. M. Pringle, Phys. Chem. Chem. Phys., 2013, 15, 1339
 L. Jin, K. M. Nairn, C. M. Forsyth, A. J. Seeber, D. R. MacFarlane, P. C. Howlett, M. Forsyth and J. M. Pringle, J. Am. Chem. Soc., 2012, 134, 9688-9697.
 L. Jin, S. de Leeuw, M. V. Koudriachova, J. M. Pringle, P. C. Howlett, F. Chen, M. Forsyth, Phys. Chem. Chem. Phys., 2013, 15, 19570-19574.
 L. Jin, P. C. Howlett, J. M. Pringle, J. Janikowski, M. Armand, D. R. MacFarlane and M. Forsyth, Energy and Environ. Sci., 2014, 7, 3352-3361.