Highly Hydroxide-Conductive Nanostructured Solid Electrolyte via Predesigned Ionic Nanoaggregates

4 years ago

Highly Hydroxide-Conductive Nanostructured Solid Electrolyte via Predesigned Ionic Nanoaggregates

Xingyu Wu, Guangwei He, Zhen Li, Shentao Jiang, Zhongyi Jiang, Chaoyi Chang, Zongyu Li, Xueyi He, Tong Huang, Shaofei Wang, Hong Wu, Xinlin Yang, Jing Zhao, Mingzhao Xu

The creation of interconnected ionic nanoaggregates within solid electrolytes is a crucial yet challenging task for fabricating high-performance alkaline fuel cells. Herein, we present a facile and generic approach to embedding ionic nanoaggregates via predesigned hybrid core–shell nanoarchitecture within nonionic polymer membranes as follows: (i) synthesizing core–shell nanoparticles composed of SiO₂/densely quaternary ammonium-functionalized polystyrene. Because of the spatial confinement effect of the SiO₂ “core”, the abundant hydroxide-conducting groups are locally aggregated in the functionalized polystyrene “shell”, forming ionic nanoaggregates bearing intrinsic continuous ion channels; (ii) embedding these ionic nanoaggregates (20–70 wt %) into the polysulfone matrix to construct interconnected hydroxide-conducting channels. The chemical composition, physical morphology, amount, and distribution of the ionic nanoaggregates are facilely regulated, leading to highly connected ion channels with high effective ion mobility comparable to that of the state-of-the-art Nafion. The resulting membranes display strikingly high hydroxide conductivity (188.1 mS cm^–1 at 80 °C), which is one of the highest results to date. The membranes also exhibit good mechanical properties. The independent manipulation of the conduction function and nonconduction function by the ionic nanoaggregates and nonionic polymer matrix, respectively, opens a new avenue, free of microphase separation, for designing high-performance solid electrolytes for diverse application realms.

Publisher URL: http://dx.doi.org/10.1021/acsami.7b05400

DOI: 10.1021/acsami.7b05400