An anion exchange polymer(QPVI-75%)has been synthesized via the quaternization reaction of poly(1-vinylimidazole)with 1-bromohexane.A series of cross-linked blend anion exchange membranes have been successfully prepared based on poly [2,2'-(p-oxydiphenylene)-5,5'-bibenzimidazole](OPBI)and the QPVI-75%at varied weight ratio of OPBI to QPVI-75%using 1,6-dibromohexane as the cross-linking agent.The resulting cross-linked blend membranes are ductile and transparent.The effect of the content of the QPVI-75%on membrane properties such as mechanical properties,thermal stability,ion exchange capacity(IEC),water uptake,swelling ratio and anion conductivity were investigated in detail.The charge-discharge performance of the single cells assembled with the cross-linked blend membranes were also studied and compared with that of the one assembled with Nafion117.The cross-linked blend membranes exhibited 3-4 orders lower VO2+permeability than Nafion117 leading to much slower self-discharge rate and significantly higher coulombic efficiency of the former.The single cell assembled with the OPBI/QPVI-75%(2:8)cross-linked blend membranes showed higher coulombic efficiency and energy efficiency compared with Nafion117 membrane at low current densities(10 – 40 mA cm-2).Furthermore,the charge-discharge cycling performance at 80 mA cm-2 of the cell assembled with the OPBI/QPVI-75%(3:7)cross-linked blend membrane displayed little decay after 300 charge-discharge cycles test.