摘要
质子交换膜燃料电池(PEMFC)能量转换效率高,发电效率受负载变化影响小,有害物和碳排放少。双极板是其关键结构部件之一,承担传递电子、分配气体、电池内水管理、支撑膜电极组件等作用。复合双极板有质轻、耐腐、成本低等优势,受到了较多的关注。然而,为了保持燃料电池的稳定运行,应保证膜电极充分润湿的情况下,确保积累在流道内的液态水顺利排出,这对于双极板的表面特性提出了新的要求。对于复合石墨板而言,可以通过极板组分与制备工艺的改变,实现接触角的调节,进而调控电池的水、气状况。本工作在鳞片石墨-树脂复合材料中,加入化学气相沉积制备的纳米碳纤维(CF-CVD)作添加剂,调控复合双极板的亲水性。同时,通过改变鳞片石墨粒径,验证其对复合双极板亲水性调控的影响。结果表明,极板表面的亲水性随着碳纤维含量的升高而增强,接触角降低幅度可达10.28°。鳞片石墨粒径影响复合双极板的接触角调控效果,为配合CF-CVD实现极板最佳亲水性,应选择500~1500目石墨作为导电基材。CF-CVD含量为3%、鳞片石墨为1000目的亲水复合双极板综合性能最佳,电导率达到239.33 S/cm,抗弯强度达到73.47 MPa。
Proton exchange membrane fuel cells(PEMFC)have the advantages of high energy conversion efficiency,low impact of load changes on power generation efficiency,and low harmful substances and carbon emissions.The bipolar plate is one of the key structural components of PEMFC and undertakes the functions of electron transfer,gas distribution,internal water management,and supporting membrane electrode components.Composite bipolar plates have advantages such as light weight,corrosion resistance,and low cost,and have received more attention.However,to maintain the stable operation of fuel cells,it is necessary that water accumulated in the flow channel can be smoothly discharged while ensuring membrane wetting.This poses new requirements for the surface characteristics of bipolar plates.For composite graphite plates,they can adjust the contact angle and regulate the water and gas conditions of PEMFCs by changing their composition and preparation process.This article introduces the addition of carbon nanofibers prepared by chemical vapor deposition(CF-CVD)in the flake graphite-resin composite materials to regulate the hydrophilicity of composite bipolar plates.Additionally,the impact of varying flake graphite particle sizes on the hydrophilicity regulation of these plates is examined.The results reveal that increased carbon fiber content enhances the surface hydrophilicity of bipolar plates,with the smallest contact angle achieving 10.28°.The particle size of flake graphite affects the contact angle of composite bipolar plates.To optimize the hydrophilicity of bipolar plates with CF-CVD,500-1500 mesh graphite is recommended as the conductive substrate.Specifically,a CF-CVD content of 3%,combined with 1000 mesh flake graphite,yields a hydrophilic composite bipolar plate with superior comprehensive performance,exhibiting a conductivity of 239.33 S/cm and a bending strength of 73.47 MPa.
作者
张璐瑶
郑俊生
樊润林
明平文
ZHANG Luyao;ZHENG Junsheng;FAN Runlin;MING Pingwen(Clean Energy Automotive Engineering Center,Tongji University,Shanghai 201804,China;College of Automotive Studies,Tongji University,Shanghai 201804,China)
出处
《材料工程》
北大核心
2025年第6期218-226,共9页
Journal of Materials Engineering
基金
国家重点研发计划项目(2018YFB1502504)。
关键词
复合双极板
接触角
纳米碳纤维
鳞片石墨
水管理
composite bipolar plate
contact angle
carbon nanofiber
flake graphite
water management
