Preparation And Characterization Of Anion Exchange Membrane And Hydroxide Conductive Binder With Non-Coplanar Multiblock Structure

Alkaline anion exchange membrane fuel cell（AAEMFC）has a lot of advantages,including the usability of non-precious electrocatalysts,the absence of carbonate crystallization and so on.With these advantages,it shows great promise as a next-generation energy technology.However,development toward practial application of AEMFC is greatly hindered by several issues,including inadequate hydroxide conductivity and stability of AEM and poor solubility of hydroxide conductive binder（HCB）in low boiling point green solvents.In view of the above background,this thesis has been focused on the three aspects as follows:1.Two new types of AEM,namely NCHP-Im（imidazolium functionalized non-coplanar homopolymer）and CBP-Im（imicazolium functionalized coplanar block copolymer）,were prepared by introducing bent-twisted units and constructing multiblock structure,respectively;their microstructure influences on conductivity of AEM were studied.It was found that non-coplanar effect significantly increased the free volume and micropores size in membranes and promoted the formation of ion clusters which could make the migration of hydroxide ions easilier.And multiblock effect significantly improved degree of microphase separation in membranes and promoted the formation of ion clusters.At room temperature,the membranes had hydroxide conductivity of 21 m S/cm and 28 m S/cm and swelling ratio of 13.3 % and 5.63 % with low IEC.2.Bent-twisted non-coplanar block copolymer（NCBP-Im）AEM was designed and fabricated.At room temperature,the NCBP-Im membrane showed a hydroxide conductivity of 35 m S/cm and swelling ratio of 4.56 % with low IEC（1.25 mmol/g）.Its H2/O2 fuel cell yielded a maximum power density of 262 m W cm^-2 at 50 ℃;its open circuit voltage was 1.07 V.These results suggest good potential of the NCBP-Im membrane for application in AEMFC.3.A novel HCB was designed and synthesized on basis of the above findings and by introducing a flexible segment in the backbone structure.The solubility of the new HCB in low boiling point green organic solvent was investigated.At room temperature,the resulting new HCB,namely NRCB-Im-6C,showed a hydroxide conductivity of 45 m S/cm and aswelling ratio of 10.12 % at an IEC of 1.43 mmol/g;its solubility in ethyl formate could reach 74 %（m HCB/Vsolvent）.To summarize,this thesis deals with the design and fabrication of bent-twisted block copolymer AEM,and has demonstrated the contributing effect of free volume on ion transport and microphase separation.On basis of these findings,a novel HCB was further obtained.This thesis is important for promoting the development of high performance AEM and HCB.