Anion trapping polymer electrolytes incorporating boroxine (B 3 O 3 ) 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 1.6x10 - 5 S cm - 1 at 30 o C and which exhibit Volger-Tamman-Fulcher (VTF) behaviour have been observed.