液晶离聚物/PMMA多孔电解质膜

Study of LCI/PMMA porous electrolyte membrane

针对聚合物电解质膜电导率低、力学性能差的问题,用一种含磺酸基团的液晶离聚物(LCI)、聚甲基丙烯酸甲酯(PMMA)、高氯酸锂(LiClO4)用溶液共混法制成多孔电解质膜。采用磺酸基团作为传输锂离子的体系,N-甲基吡咯烷酮(NMP)为增塑剂。孔隙率测定和扫描电镜表明:膜为多孔状结构,孔隙率为16.4%～29.3%。孔径在1～9μm。红外光谱结果表明,磺酸基团的-OH峰3 435 cm-1在加入LiClO4之后,-OH的峰值移到3 556 cm-1。在加入NMP后,移到3 598 cm-1。交流阻抗研究表明:在25℃下,电解质膜的LCI含量25%时,离子传导率达2.60×10-6 S/cm,在膜中加入20%NMP时,离子传导率达到3.86×10-3S/cm。

In view of the low ion conductivity and the bad mechanical strength of the polymer electrolyte membrane, a new type of liquid crystalline ionomers （LCI）/PMMA porous polymer electrolyte membrane was made by LCI with the sulfonic acid groups, polymethyl methacrylate（PMMA） and the lithium perchlorate（LiCIO4） with the solvent method blending preparation. It adopted the sulfonic acid groups to transmit the lithium ion. The N-methyl pyrrolidone （NMP） was the plasticizer. The factor of porosity determination and the SEM indicate： the membrane is porous; the factor of porosity is 16.4%-29.3%; the aperture is in 1-9 μm. The infrared spectrum result indicates that the -OH peak of the sulfonic acid groups is 3 435 cm-1.Affer adding LiCIO4, -OH peak moves to 3 556 cm-1; after adding NMP, moves to 3 598 cm-1. The AC impedance result indicates： when the liquid crystal ionomers content achieves 25% at 25 ℃, it exhibits ion conductivity in the order of 2.60 × 10^-6 S/cm and 3.86 × 10^-3 S/cm with 20% NMP.