带有支撑层的一体式再生燃料电池新结构及性能分析

Novel Structure Design and Performance Analysis of Unitized RegenerativeFuel Cell with Support Layer

针对一体式再生燃料电池(URFC)双向性能低的问题,以多孔传输层(PTL)与催化剂涂覆膜(CCM)之间界面接触为切入点,提出一种包含支撑层的新型URFC结构,并对PTL结构参数进行优化。通过极化曲线和电化学阻抗谱分析了不同结构URFC的性能。实验发现:钛毡纤维结构细密化有利于提升URFC双向性能,当电流密度为1.5 A/cm 2时,带有支撑层的URFC相比传统URFC,在燃料电池模式下电压上升了69 mV,在电解槽模式下电压下降了12 mV;新结构URFC具有更小的接触阻抗及质子传输阻抗,比燃料电池模式的高频阻抗下降了16.2%。压敏纸实验和电镜测试表明,支撑层可以使催化层与PTL之间的宏观接触应力分布更加均匀,改善了钛纤维与催化层之间界面的微观接触状态,有利于提高电子传输效率及反应动力。研究可为一体式再生燃料电池结构设计及优化提供参考。

Unitized regenerative fuel cell(URFC)has always been limited by its unsatisfactory polarization performance.To address this problem,in this paper,a novel URFC structure design with support layer(SL)is proposed with the interface contact between porous transport layer(PTL)and catalyst coated membrane(CCM)as the starting point,and PTL structure parameters are optimized.Polarization curves and electrochemical impedance spectroscopy(EIS)are referred to for analyses on the performance of URFCs with different structures.It is found by experiment that the densification of the fiber structure for titanium felt is beneficial to improve the polarization performance of URFC.The novel URFC structure with a support layer offers a voltage rise of 69 mV in FC mode and a voltage drop of 12 mV in WE mode at 1.5 A/cm 2 compared with those of traditional URFC.Furthermore,the novel URFC structure facilitates the reduction of contact and proton transfer impedance,while decreasing the high frequency impedance(HFR)by 16.2%in FC mode.Through pressure-sensitive paper experiments and electron microscope test,it is demonstrated that the novel structure could result in a more uniform macroscopic contact stress distribution between CCM and PTL and a better microscopic contact state at the interface between titanium fibers and CCM,which is beneficial to improve the electron transfer efficiency and reaction kinetics.This study provides reference for the structural design and optimization of URFC.