Anion trapping polymer electrolytes incorporating boroxine (B3O3) rings and oligoether side chains have been demonstrated to combine high Li+ ion transference numbers, thermal stability and an electrochemical stability window in the region of 4.9 V. Ionic conductivities of up to 1.6 X 10(-5) S cm(-1) at 30 degrees C and which exhibit Volger-Tamman-Fulcher (VTF) behaviour have been observed.