Assemblies of protective anion exchange membrane on air electrode for its efficient operation in aqueous alkaline electrolyte
Assemblies of protective anion exchange membrane on air electrode for its efficient operation in aqueous alkaline electrolyte
复制标题
DOI：
10.1016/j.jpowsour.2014.10.079
复制
发表时间：
2015-01
影响因子：
9.2
通讯作者：
Bruno Bertolotti;L. Chikh;C. Vancaeyzeele;S. Alfonsi;O. Fichet
中科院分区：
文献类型：
--
作者：
Bruno Bertolotti;L. Chikh;C. Vancaeyzeele;S. Alfonsi;O. Fichet
水碱性金属-空气电池是一种很有前途的能量储存装置，当提供大气空气时。然而，在这种条件下，空气电极的寿命很短（即在5 M LiOH中，在−10 mA cm−2下工作50 h），主要是由于电极孔隙内碳酸盐的沉淀。然后，空气电极可以被电解质侧的阴离子交换膜保护。在本文中，我们证明了这种保护膜的效率取决于电极上的组装方法。当在电极上直接合成修饰的聚环氧氯丙烷（PECH）网络时，聚合物会渗透到电极孔隙中，并且与传统的压力组装膜相比，得到了一个合适的界面，可以忽略额外的极化。这种受保护的电极显示出在5 M LiOH中长达160小时操作的稳定性。通过调整电导率和离子交换容量，将该性能提高到350 h。最后，与单一网络相比，互穿聚合物网络（IPN）结构更有意义。事实上，用聚乙二醇/聚（2-羟乙基甲基丙烯酸酯）（PHEMA） IPN保护的电极在5m LiOH中稳定650小时。此外，降解过程变得可逆，因为组装可以再生，这是不可能的裸电极。
Aqueous alkaline metal-air batteries represent promising energy storage devices when supplied with atmospheric air. However, under this condition, the air electrode shows a very short life time (i.e. 50 h of operation in 5 M LiOH at −10 mA cm−2), mainly due to the precipitation of carbonates inside the electrode porosity. The air electrode can then be protected by an anion exchange membrane on the electrolyte side. In this paper, we demonstrate that the efficiency of this protective membrane depends on the assembly method on the electrode. When a modified poly(epichlorohydrin) (PECH) network is synthesized directly on the electrode, the polymer seeps inside the electrode porosity, and a suitable interface inducing negligible additional polarization in comparison with classical pressure-assembled membranes is obtained. This protected electrode shows improved stability of up to 160 h of operation in 5 M LiOH. This performance is improved to 350 h by adjusting the conductivity and the ionic exchange capacity. Finally, the interest of interpenetrating polymer network (IPN) architecture compared to a single network is confirmed. Indeed, an electrode protected with a PECH/poly(2-hydroxyethyl methacrylate) (PHEMA) IPN is stable for 650 h in 5 M LiOH. In addition, degradation process becomes reversible since the assembly can be regenerated, which is not possible for the bare electrode.