Communication: Enhanced cation transport in polymer electrolytes, with consequent improved performance in batteries and other electrochemical applications, is reported. In general, ionic transport in polymer electrolytes is closely coupled to segmental motion of the backbone, leading to severely restricted cation mobility as the glass transition temperature T-g is approached. In the new side-group liquid-crystalline polymer electrolyte system described here, the ionic conductivity is shown to be insensitive to T-g, with sub-T-g conductivities of similar to 10(-5) Scm(-1). An explanation for this behavior is proposed.