Development of Membranes and Separators to Inhibit Cross‐Shuttling of Sulfur in Polysulfide‐Based Redox Flow Batteries: A Review

Abstract

The global rapid transition from fossil fuels to renewable energy resources necessitates the implementation of long‐duration energy storage technologies owing to the intermittent nature of renewable energy sources. Therefore, the deployment of grid‐scale energy storage systems is inevitable. Sulfur‐based batteries can be exploited as excellent energy storage devices owing to their intrinsic safety, low cost of raw materials, low risk of environmental hazards, and highest theoretical capacities (gravimetric: 2600 Wh/kg and volumetric: 2800 Wh/L). However, sulfur‐based batteries exhibit certain scientific limitations, such as polysulfide crossover, which causes rapid capacity decay and low Coulombic efficiency, thereby hindering their implementation at a commercial scale. In this review article, we focus on the latest research developments between 2012–2023 to improve the separators/membranes and overcome the shuttle effect associated with them. Various categories of ion exchange membranes (IEMs) used in redox batteries, particularly polysulfide redox flow batteries and lithium‐sulfur batteries, are discussed in detail. Furthermore, advances in IEM constituents are summarized to gain insights into different fundamental strategies for attaining targeted characteristics, and a critical analysis is proposed to highlight their efficiency in mitigating sulfur cross‐shuttling issues. Finally, future prospects and recommendations are suggested for future research toward the fabrication of more effective membranes with desired properties.

Recent Developments on Electroactive Organic Electrolytes for Non‐Aqueous Redox Flow Batteries: Current Status, Challenges, and Prospects

“…NARFBs represent an emerging class of energy storage technologies that offer several advantages compared to already developed technologies, such as aqueous redox flow batteries (ARFBs), lithium-ion batteries (LIBs), supercapacitors (SCs), hybrid supercapacitors (HSCs), and other conventional methods. [20][21][22][23][24] NARFB technology has several advantages such as high efficiency, high energy density, long cycle life, fast response times, safety, and scalability. Moreover, NARFBs can utilize a variety of redox couples to make it a cost-effective and viable storage option.…”

“…The operating voltage potential ranged from 1.8 to 2.7 V versus Li/Li + while using 0.05 M of molecule 1 or 2 dissolved in tetraethylene glycol dimethyl ether (TEGDME) and 1.3 M lithium bis(trifl uoromethanesulfonyl)imide (LiTFSI) salt in the cell. The initial discharge capacities of quinones 1 and 2 were 169 and (24)(25)(26)(27)(28)(29)(30) in acetonitrile. [44] Copyright © American Chemical Society, 2015.…”

“…Figure 5. Solubility of chromium complexes(24)(25)(26)(27)(28)(29)(30) in acetonitrile [44]. Copyright © American Chemical Society, 2015.…”

Recent Development of Electrolytes for Aqueous Organic Redox Flow Batteries (Aorfbs): Current Status, Challenges, and Prospects

“…Mitigation of this crossover of electrochemically active molecules necessitates a separator/ membrane with high molecular selectivity. [136] Membrane selectivity is typically attributed to physical blocking, electrostatic exclusion, and Donnan exclusion. These effects enable various engineering processes to improve the isolation of redox species.…”

Beyond conventional batteries: a review on semi-solid and redox targeting flow batteries-LiFePO4 as a case study

“…Pumps ensure the circulation of the electrolytes in order to renew each reagent on the surface of the corresponding electrode. 11–13…”