Recent Development in Composite Membranes for Flow Batteries

Abstract

Figure 13. a) Schematicillustration of selection principle duringt he ion transportprocess of aP IM-1.b)Permeability of protons and VO 2 +. [36b] Reproduced with permission from Ref. [36b].Copyright2 016. Wiley-VCH.

Review of the Development of First‐Generation Redox Flow Batteries: Iron‐Chromium System

“…Nevertheless, it is worth mentioning that non‐perfluorinated membranes (AEM and CEM) and porous membranes with high ion selectivity and chemical stability are still the hotspots of the future development of ICRFB membrane materials [64] . Modifications of perfluorinated membranes, including inorganic‐organic hybrid, polymer blending, and amphoteric membranes need to be further investigated to ameliorate the ionic selectivity, as the developing trend of membranes for vanadium‐based RFB system [4,73] …”

“…As the name suggests, two independent electrolyte solutions undergo redox reactions in the corresponding half-cell of the battery during system charging and discharging, so as to store (charging cycle) or release (discharging cycle) electrical energy. [4] The volume and concentration of the catholyte/anolyte determine the energy storage capacity of the battery. On the other hand, the power of the RFB depends on the system design (the number of individual cells and the size of electrodes).…”

“…The catholyte/anolyte is stored in reservoirs outside the active battery area and pumped through the battery system as needed. As the name suggests, two independent electrolyte solutions undergo redox reactions in the corresponding half‐cell of the battery during system charging and discharging, so as to store (charging cycle) or release (discharging cycle) electrical energy [4] . The volume and concentration of the catholyte/anolyte determine the energy storage capacity of the battery.…”

Synthesis and Characterization of Lithium-Conducting Composite Polymer–Ceramic Membranes for Use in Nonaqueous Redox Flow Batteries

“…[4][5][6][7] Despite this intriguing possibility, current NAqRFB prototypes display limited performance and lifetime due, at least in part, to the lack of membranes with suitable combinations of selectivity, conductivity, and stability. [8][9][10][11] Ideally, a RFB membrane should simultaneously block undesired transport of redox-active species and solvent between the positive and negative electrolytes, promote the rapid and selective transport of supporting ions, possess high mechanical and chemical stability, and be conducive to low-cost and scalable production. 12 In practice, this is difficult to implement, and while there have been considerable efforts dedicated to advancing redox chemistries for NAqRFBs, thus far, fewer attempts have focused on developing membranes to support leading chemistries, frustrating full cell performance and durability.…”

“…12 In practice, this is difficult to implement, and while there have been considerable efforts dedicated to advancing redox chemistries for NAqRFBs, thus far, fewer attempts have focused on developing membranes to support leading chemistries, frustrating full cell performance and durability. [8][9][10][11] Most prior research on NAqRFBs incorporates commercially available ion-exchange membranes, 13,14 which are not specifically engineered for nonaqueous electrochemical environments and thus typically display unfavorable combinations of ionic conductivity and species selectivity. [15][16][17] Therefore, new separation approaches must be considered, with particular emphasis on materials developed for energy storage technologies that operate in similar (electro)chemical environments.…”