Ultrathin composite membrane of alkaline polymer electrolyte for fuel cell applications
Ultrathin composite membrane of alkaline polymer electrolyte for fuel cell applications
复制标题
用于燃料电池应用的碱性聚合物电解质超薄复合膜
DOI：
10.1039/c3ta12626a
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发表时间：
2013-01-01
影响因子：
11.9
通讯作者：
Zhuang, Lin
中科院分区：
文献类型：
--
作者：
Li, Guangwei;Pan, Jing;Zhuang, Lin
为了使燃料电池电池电压中的欧姆损失最小化，电解液应尽可能薄，特别是当使用碱性聚合物电解质（ape）时，其迁移率和OH-浓度都相对较低。制造APE薄膜的一种实用策略是将APE离聚体浸透到超薄的刚性框架（如多孔PTFE薄膜）中，这样具有高离子交换容量（IEC）的APE就能实现高离子传导，同时坚固的主体也能提供良好的机械稳定性。我们之前的研究已经使用这种复合膜实现了APE燃料电池（APEFC）的原型，但后来我们发现，由于QAPS客体与PTFE主体之间的相互作用较差，在燃料电池运行条件下，APE组分季铵盐聚砜（QAPS）会逐渐浸出。为了解决这一问题，我们在本工作中展示了一种制备超薄复合膜的新方法。将APE离聚体（TQAPS）浸渍在多孔PTFE薄膜中，然后进行自交联过程，形成半互穿网络。制备的超薄复合膜（xQAPS@PTFE， 25 μ m厚）耐80℃水浸，面积阻力低（0.09 ω cm(2)），溶胀度低（60℃时为3.1%），机械强度高（31 MPa）。利用这种xQAPS@PTFE膜，H-2-O-2 APEFC在60℃、0.1 MPa背压下的峰值功率密度为550 mW cm(2)。
To minimize the ohmic loss in the cell voltage of fuel cells, the electrolyte should be made as thin as possible, in particular when alkaline polymer electrolytes (APEs) are employed, where both the mobility and the concentration of OH- are relatively low. A practical strategy for fabricating thin APE membranes is to impregnate APE ionomers into an ultrathin, rigid framework (such as a porous PTFE film), so that high ion conduction is achieved by the APE with a high ion-exchange capacity (IEC), while good mechanical stability is provided by the robust host. Our previous study has realized a prototype of an APE fuel cell (APEFC) using this kind of composite membrane but we found later that the APE component, quaternary ammonium polysulfone (QAPS), will leach out gradually under fuel cell operating conditions because of the poor interaction between the QAPS guest and the PTFE host. To address this problem, we demonstrate in the present work a new approach for making ultrathin composite membranes of APEs. The APE ionomer (TQAPS) is impregnated into a porous PTFE film, followed by a self-crosslinking process, so as to form a semi-interpenetrating network. The resulting ultrathin composite membrane (xQAPS@PTFE, 25 mu m thick) is highly tolerant to leaching in 80 degrees C water and possesses low area resistance (0.09 Omega cm(2)), a low swelling degree (3.1% at 60 degrees C) and high mechanical strength (31 MPa). Making use of such an xQAPS@PTFE membrane, the H-2-O-2 APEFC exhibits a peak power density of 550 mW cm(2) at 60 degrees C under 0.1 MPa of back pressure.