| All Vanadium Redox Flow Battery（VRB）is a new type of high-efficiency,largescale,electrochemical energy storage equipment used in conjunction with wind energy and solar energy plants.The utility model has the advantages of quick start response speed,long service life,high energy density,flexible system assembly,simple maintenance operation,safety and environmental protection.The battery separator is a key component of the battery.The polyaryletherketone material containing adamantane structure is selected is due to the adamantane structure is similar to the lattice unit of diamond,which has a high melting point（269 °C）,high thermal stability,strong hydrophobicity.Introducing adamantane structure in the polymer main chain is expected to improve the hydrophobicity,thermal stability and glass transition temperature of the material.The purpose of this thesis is to modify the material by chloromethylation/quaternization method based on the polyarylene ether ketone polymer containing adamantane structure synthesized by this experimental group,in order to achieve an all-vanadium flow battery anion exchange membrane,which is suitable for high current density.In this paper,nitrobenzene was used as solvent to modify chloromethylation of 2-adamantane polyaryletherketone（2-ADMPEK）and 1,3-adamantane polyaryletherketone（1,3-ADMPEK）.The obtained CM2-ADMPEK and CM1,3-ADMPEK were characterized by infrared spectroscopy and nuclear magnetic resonance spectroscopy.The amount of the chloromethylating agent was changed,and the obtained chloromethylated polymers having different degrees of substitution were immersed in trimethylamine for amination.Finally,Q2-ADMPEK and Q1,3-ADMPEK were obtained.The water absorption,swelling ratio,sheet resistance,vanadium ion permeability,ion exchange capacity（IEC）,chemical stability,current efficiency,and voltage efficiency of Q2-ADMPEK with different degrees of substitution were systematically investigated.And the Q2-ADMPEK film excels in both in situ and ex situ chemical stability tests.Q2-ADMPEK-4,at a current density of 140 m A cm-2,can achieve high performance of CE98.3 %,VE 82.0 %,EE 80.6 %,compared to N117 under the same conditions（CE95.2 %,VE of 84.6 %,EE 80.5 %）and N212（CE 86.8 %,VE 88.8 %,EE 77.1 %）is much higher.The asymmetric composite anion exchange membrane was prepared by using Q2-ADMPEK-A materials with different drying times.The effects of different degrees of drying on various aspects of the membrane were investigated systematically.The hydrophilicity and sheet resistance of the membrane which is not completely dried are always smaller than that of the completely dried membrane.In terms of battery performance,the membrane that is not completely dried has a lower battery efficiency as the current density increases compared to a completely dried membrane,indicating that the asymmetric membrane is more suitable for use at high current densities.At a current density of 160 m Acm-2,the current efficiency and voltage efficiency of the Q2-ADMPEK-A-2 membrane with a drying time of 160 minutes were 98.29% and 82.09%,respectively,which was higher than that of Nafion117 by 96.7 % and 75.15 %.The energy efficiency of the Q2-ADMPEK-A-3 asymmetric membrane with a drying time of 190 minutes reached 80.68 %,which was higher than 72.67% of Nafion117.The water absorption,swelling ratio,area resistance,vanadium ion permeability,ion exchange capacity（IEC）,chemical stability,current efficiency,voltage efficiency,energy efficiency and other parameters of Q1,3-ADMPEK with different degrees of substitution were also investigated.Q1,3-ADMPEK-3 achieves high performance of CE98.9 %,VE 84.0 %,and EE 83.0 % at a current density of 140 m A cm-2.At higher current densities of 160 m A cm-2,EE is still above 80%. |
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