Porous Ceramic Metal-Based Flow Battery Composite Membrane

In metal-based flow battery, membranes significantly impact energy conversion efficiency and security. Unfortunately, damages to the membrane occur due to gradual accumulation of metal dendrites, causing short circuits and shortening cycle life. Herein, we developed a rigid hierarchical porous ceramic flow battery composite membrane with a sub-10-nm-thick polyelectrolyte coating to achieve high ion selectivity and conductivity, to restrain dendrite, and to realize long cycle life and high areal capacity. An aqueous zinc-iron flow battery prepared using this membrane achieved an outstanding energy efficiency of >80%, exhibiting excellent long-term stability (over 1000 h) and extremely high areal capacity (260 mAh cm-2). Low-field nuclear magnetic resonance (NMR) spectroscopy, small-angle X-ray scattering, in situ infrared spectroscopy, solid-state NMR analysis, and nano-computed tomography revealed that the rigid hierarchical pore structures and numerous hydrogen bonding networks in the membrane contributed to the stable operation and superior battery performance. This study contributes to the development of next-generation metal-based flow battery membranes for energy and power generation.

Advanced Materials for Zinc-Based Flow Battery: Development and Challenge

Zinc-based flow batteries (ZFBs) are well suitable for stationary energy storage applications because of their high energy density and low-cost advantages. Nevertheless, their wide application is still confronted with challenges, which are mainly from advanced materials. Therefore, research on advanced materials for ZFBs in terms of electrodes, membranes, and electrolytes as well as their chemistries are of the utmost importance. Herein, the focus is on the scientific understandings of the fundamental design of these advanced materials and their chemistries in relation to the battery performance. The principles of using different materials in different ZFB technologies, the functions and structure of the materials, and further material improvements are discussed in detail. Finally, the challenges and prospects of ZFBs are summarized as well. This review provides valuable instruction on how to design and develop new materials as well as new chemistries for ZFBs.