质子交换膜燃料电池梯度扩散层水传输研究

为考察梯度扩散层排水能力,通过自制的测试装置测量了梯度扩散层液态水爆破压力和临界相饱和度;通过称重法测量了梯度扩散层液态水的残留量,并对梯度扩散层液态水过水流率和液态水残留量进行了理论计算.结果表明:与均匀扩散层比较,梯度扩散层能提高液态水排水量,降低液态水残留量.理论计算的两种结构梯度扩散层的液态水过水流率比均匀扩散层分别增加了152.82 %和171.85 %,液态水的残留量分别减少了23.73 %和35.42 %;由梯度扩散层组装的燃料电池比普通电池具有更好的性能.

Water transport in gradient gas diffusion layer of proton exchange membrane fuel cells

The liquid water breakthrough pressure and critical saturation of the gradient gas diffusion layers(GDLs) were measured by a test set,in order to study water draining performance of gradient GDLs.The liquid water remaining in the GDLs was also measured by a method of weighing the dry and wet GDLs.The liquid flux through different gradient GDLs and the liquid water remaining in the GDLs were calculated by a theoretic method.It is concluded that the gradient GDLs increases the liquid flux while decreases the liquid water remaining in GDLs when compared with the uniform GDLs.The calculation results show that the liquid water flux through two different gradient GDLs is separately 152.82 % and 171.85 % more than that through the uniform GDLs,while the liquid water remaining in the GDLs is separately 23.73 % and 35.42 % less than that in the uniform GDLs.Fuel cell assembled with gradient GDLs has better performance than that of common fuel cells.