We study suspensions of synthetic clay Laponite at very low ionic strength. We show the existence, for these charged disk-like particles, of a liquid-soft solid transition mainly driven by electrostatic repulsive interactions. Such a process defines a re-entrant transition line in the phase diagram. Location of this line is predicted using basic arguments. The structure is characterized by ultra-small-angle X-ray scattering (USAXS). Soft-solid suspensions show a correlation peak compatible with long-range electrostatic stabilization. Such a result strongly contrasts with the evolution of the scattering spectra for solid-like suspensions of Laponite at high ionic strength (above 10 −4 M). Close inspection of this correlation peak reveals that individual particle distribution is not homogeneous in space.Colloidal systems undergo phase transitions such as liquid-solid, order-disorder, sol-gel or glass transition [1-6], which are of important technical and scientific interest. Phase transitions involving, for example, purely repulsive interactions (the so-called Kirkwood-Alder transition [3]) are now well established [3][4][5][6] for spherical charged particles (latex, SiO 2 ). This is not the case for suspensions of charged disk-like colloids where the origin and the status of the so-called phase diagram are still under debate [7][8][9][10][11][12]. A demonstrative example is the case of Laponite, a synthetic smectite clay which can be considered, on average, as a hard disc having a thickness of 1nm, an average diameter of 300 Å and a bulk density of 2.65 • 10 6 kg/m 3 . This material has recently generated a good deal of experimental and theoretical studies [8][9][10][11][12][13][14][15][16][17][18][19]. Above an ionic strength of 10 −4 M, several authors have observed a transition line from a liquid to a soft solid when the solid concentration C (expressed as the mass of solid over the

Self-assembling, nanophase-separated multi-block copoly(arylene sulfone)s, selectively swelled with ethylene carbonate, provide excellent single-ion conductivity and cycling stability for high-energy lithium/Li[Ni1/3Co1/3Mn1/3]O2 batteries.

This perspective reviews current strategies to decouple segmental motion and ionic conductivity for lithium polymer battery electrolytes, including an outlook for potential future improvements.