质子交换膜燃料电池双极板用不锈钢的聚苯胺涂层改性  

Electrodeposited polyaniline coating on stainless steel for bipolar plates of proton exchange membrane fuel cell

作　　者：江自然[1] 肖海波[1] 阳东方[1] 刘宇尘[1] 姚锐[1] 郑峰[1,2] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2014年第2期285-292,共8页Materials Science and Engineering of Powder Metallurgy

基　　金：中南大学粉末冶金国家重点实验室开放课题

摘　　要：将苯胺单体滴加到硫酸溶液中配制成电解液,采用恒电流法在304不锈钢板表面沉积聚苯胺涂层,通过动电位极化和恒电位极化分析不锈钢板的防腐性能,利用自制的导电性能测试设备分析涂层与不锈钢板的界面接触电阻,探讨聚苯胺涂层用于质子交换膜燃料电池双极板改性的可能性。结果表明,在优化工艺条件下制备的聚苯胺涂层的腐蚀电位和腐蚀电流密度分别为369 mV和0.479μA/cm2,与裸钢相比,腐蚀电位升高536 mV,腐蚀电流密度降低4个数量级。模拟质子交换膜燃料电池的实际工作环境进行恒电位极化曲线测试,分析测试后的溶液离子含量。结果表明,涂层改性不锈钢板的腐蚀电流密度比裸钢低2个数量级,具有很好的耐久性;阳极环境比阴极环境具有更强的腐蚀性。恒电位极化测试前,压力为1.4 MPa时,裸钢和涂层试样的界面接触电阻分别为97和145 mΩ·cm2,腐蚀后涂层试样的界面接触电阻比裸钢的低更多。用聚苯胺改性的不锈钢的防腐和导电性能在一定程度上都能达到目标值,在质子交换膜燃料电池双极板中具有很大的应用潜力。Polyaniline （PANI） coating was deposited on 304 stainless steel （SS） by galvanostatic method from aqueous solutions of aniline and sulfuric acid. The properties of PANI coating were tested to study its feasibility used for bipolar plates of proton exchange membrane fuel cell （PEMFC）. Potentiodynamic and potentiostatic tests were conducted to investigate its corrosion resistance. The present author’s home-made electrical conductivity testing equipment was used to examine its interfacial contact resistance （ICR）. Potentiodynamic test results showed that the corrosion potential for PANI coated SS prepared at optimal condition was 369 mV, which was 536 mV higher than that of the bare one. And its corrosion current density was 0.479μA/cm-2, four orders of magnitude less than that of the bare one. Potentiostatic tests in simulated PEMFC environments were conducted and the metal ion content in the testing solutions was analyzed. Results show that corrosion current density for PANI coated SS is two orders of magnitude less than that of the bare one, indicating that PANI coated SS has higher chemical stability. The anode condition is more corrosive than the cathode one. ICRs of bare and coated SS were 97 and 145 mΩ·cm2 at 1.4 MPa before potentiostatic tests, respectively. After potentiostatic tests, PANI coated sample exhibited lower ICR than the bare one. Therefore, PANI coated SS has a great potential of application in bipolar plates of PEMFC as its corrosion resistance and conductivity may satisfy the properties targets of metallic bipolar plates to some extent.

关 键 词：双极板 质子交换膜燃料电池 聚苯胺涂层 防腐蚀 界面接触电阻 

分 类 号：TM911.4[电气工程—电力电子与电力传动]