聚苯胺膜/不锈钢复合双极板的耐蚀性和导电性  

Corrosion Resistance and Electrical Conductivity of Polyaniline Film/Stainless Steel Composite Bipolar Plate

作　　者：周婉秋 杨佳宇 刘晓安 姜文印 辛士刚 康艳红 ZHOU Wan-qiu;YANG Jia-yu;LlUXiao-an;JIANG Wen-yin;XIN Shi-gang;KANG Yan-hong(School of Chemistry and Chemical Engineering,Shenyang Normal University,Shenyang 110034,China)

机构地区：[1]沈阳师范大学化学化工学院

出　　处：《表面技术》2019年第12期320-327,共8页Surface Technology

基　　金：辽宁省教育厅重点实验室基础研究项目(LZ2015066)~~

摘　　要：目的在316L不锈钢(SS)表面沉积聚苯胺(PANI)薄膜,制备PANI/316L SS复合材料双极板,提高316LSS在质子交换膜燃料电池工作环境下的耐腐蚀性能和导电性能。方法采用循环伏安法,在0.1 mol/L苯胺单体与0.2 mol/L H2SO4组成的水溶液中,在316L SS基体上电化学聚合PANI薄膜。采用SEM观察表面形貌,采用FTIR和Raman分析PANI官能团结构,采用XPS分析PANI膜中元素组成和化学键合状态。采用开路电位(OCP)、极化曲线和电化学阻抗谱(EIS)研究PANI/316L SS腐蚀性能。采用四探针技术研究PANI膜的导电性。结果SEM观察显示PANI膜为纤维状堆积物。红外光谱发现苯环、醌环和S==O伸缩振动,拉曼光谱发现掺杂态的半醌自由基C-N^+·,确定合成的PANI具有中间氧化态结构。XPS分析表明,聚合过程发生了质子酸掺杂,"对阴离子"(SO4^2-)进入PANI分子链中,掺杂度为3%~4%。电化学测试表明,PANI/316L SS的OCP为0.15~0.25 V,PANI使316L SS腐蚀倾向降低,随着Cl^-浓度的升高,腐蚀电流密度增大。结论在酸性含Cl-介质中,PANI/316L SS体系耐蚀性好,膜/基界面处保护性氧化膜Fe2O3和Cr2O3的形成,使PANI/316L SS体系耐腐蚀性能提高。在制备条件下,PANI膜厚度介于146~315μm之间,电导率范围为1.33~8.91 S/cm。The work aims to improve the corrosion resistance and electrical conductivity of 316 L SS in the proton exchange membrane fuel cell(PEMFC)working environment by depositing conductive polyaniline(PANI)film on the surface of 316 L stainless steel(SS)and preparing PANI/316 L SS composite bipolar plate.The PANI film was electrochemically polymerized on the surface of 316 L SS substrate by cyclic voltammetry in an aqueous solution of 0.1 mol/L aniline monomer and 0.2 mol/L H2 SO4.The surface morphology was observed by SEM,the structure of PANI functional group was analyzed by FTIR and Raman spectrum,and the element composition and chemical bond state in PANI film were analyzed by XPS.Open circuit potential(OCP),polarization curve and electrochemical impedance spectroscopy(EIS)were used to study the corrosion performance of PANI/316 L SS.Four-probe technique was applied to test electrical conductivity of PANI film.From SEM observation results,PANI film was a fibrous accumulation film.The stretching vibration of benzene ring,quinone ring and S==O was found in the infrared spectrum,and the semi-quinone free radical C-N^+·was found in the Raman spectrum,confirming that the synthesized PANI had an intermediate oxidation state structure.XPS analysis showed that proton acid doping occurred during polymerization process,and the"counter anion"(SO4^2-)entered the PANI molecular chain with a doping degree of 3%~4%.Electrochemical test results showed that the OCP of PANI/316 L SS was 0.15~0.25 V,the PANI film reduced the corrosion tendency of 316 L SS,and the corrosion current density increased with the increase of Cl^- concentration.PANI/316 L SS system has good corrosion resistance in acidic Cl^- containing media,and the formation of protective oxide film Fe2 O3 and Cr2 O3 at the film/substrate interface improves the corrosion resistance of the PANI/316 L SS system.The thickness of PANI film is 146~315μm and the conductivity is 1.33~8.91 S/cm in preparation conditions.

关 键 词：聚苯胺薄膜 不锈钢双极板 循环伏安法 耐蚀性 导电性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]