以硫酸肼(HS)、对苯二甲酸(TPA)、4,4′-联苯醚二甲酸(DPE)为单体,发烟硫酸做溶剂和脱水剂一步合成了一系列不同TPA和DPE单体配比的磺化聚芳二唑(SPOD),再通过氢氧化锂中和得到聚芳二唑磺酸锂(Li-SPOD)聚合物电解质,采用浇铸成膜法制得Li-SPOD电解质膜,研究改变TPA和DPE两种单体配比对Li-SPOD结构及性能的影响。结果表明,几种不同单体配比均能实现在聚合过程中一步得到SPOD,磺酸基团接枝在DPE结构的苯环上,并且可以达到理论接枝量;同时Li-SPOD电解质膜的聚集态结构差异很小;热性能的表现均非常优异,初始热分解温度都在450 ℃以上;力学性能随DPE单体含量的增加稍有下降但依然保持在较高的水平;电导率约为10^-5S/cm级别,随DPE含量增加而逐渐降低;Li-SPOD固态电解质电化学稳定性较好,对锂稳定电化学窗口均在4.0 V以上。
A series of sulfonated polyoxadiazoles (SPOD) with different monomer ratios were synthesized by using hydrazine sulfate (HS), terephthalic acid (TPA) and 4,4'-diphenyl ether dicarboxylic acid (DPE) as monomers, fuming sulfuric acid as solvent and dehydrating agent. Then, the SPOD films were obtained by the solution casting method. Finally, the SPOD films were neutralized with lithium hydroxide to form Li-SPOD polymer electrolytes films. The effects of two monomer ratios of TPA and DPE on the structure and properties of Li-SPOD were studied. Results show that SPOD can be obtained with different monomer ratios, and the sulfonic acid group was grafted on the benzene ring of DPE chain segments. The aggregation structure difference among Li-SPOD electrolyte films is small. Their thermal stabilities are excellent, and the initial thermal decomposition temperature are all above 450 ℃. The mechanical properties of Li-SPOD films decrease slightly with the increase of DPE contents. The conductivities of Li-SPOD electrolyte films are about 10^-5S·cm^-1, and gradually decrease with the increase of DPE content. Their electrochemical stability are good, and the decomposition voltages are all above 4.0 V.
Energy Storage Science and Technology
lithium sulfonated polyoxadiazoles
single ion conductor