Sharmoukh Walid
Inorganic Chemistry Department, National Research Centre (NRC) El Buhouth St., Dokki Cairo 12622 Egypt
RSC Adv. 2025 Apr 3;15(13):10106-10143. doi: 10.1039/d5ra00296f. eCollection 2025 Mar 28.
The rapid development and implementation of large-scale energy storage systems represents a critical response to the increasing integration of intermittent renewable energy sources, such as solar and wind, into the global energy grid. Redox flow batteries (RFBs) have emerged as a promising solution for large-scale energy storage due to their inherent advantages, including modularity, scalability, and the decoupling of energy capacity from power output. These attributes make RFBs particularly well-suited for addressing the challenges of fluctuating renewable energy sources. Several redox couples have been investigated for use in RFBs, some of which have already achieved commercialization. However, advancement in RFBs technology faces significant hurdles spanning scientific, engineering, and economic domains. Key challenges include limited energy density, high overall costs, electrolyte instability, and issues related to solvent migration across cation exchange membranes, leading to cross-contamination between anolyte and catholyte. Additionally, anion exchange membranes introduce reverse flow complications, and graphite felt used in the catholyte compartment is susceptible to corrosion. These issues necessitate ongoing research to develop viable solutions. This comprehensive review provides an in-depth analysis of recent progress in electrolyte technologies, highlighting improvements in electrochemical performance, stability, and durability, as well as strategies to enhance the energy and power densities of RFBs. Moreover, it classifies various three-dimensional (3D) electrode materials, including foam, biomass, and electrospun fibers, and examines how their structural and compositional modifications can facilitate improved mass transport and increase active sites for redox reactions in vanadium redox flow batteries (VRFBs). By exploring innovative electrode designs and functional enhancements, this review seeks to advance the conceptualization and practical application of 3D electrodes to optimize RFB performance for large-scale energy storage solutions.
大规模储能系统的迅速发展和应用，是应对太阳能、风能等间歇性可再生能源日益融入全球能源电网这一问题的关键举措。氧化还原液流电池（RFB）因其固有的优势，如模块化、可扩展性以及能量容量与功率输出的解耦，已成为大规模储能的一种有前景的解决方案。这些特性使RFB特别适合应对可再生能源波动带来的挑战。已对几种氧化还原对用于RFB进行了研究，其中一些已实现商业化。然而，RFB技术的进步面临着科学、工程和经济等领域的重大障碍。关键挑战包括能量密度有限、总体成本高、电解质不稳定以及与溶剂跨阳离子交换膜迁移相关的问题，这会导致阳极电解液和阴极电解液之间的交叉污染。此外，阴离子交换膜会引发逆流并发症，阴极电解液隔室中使用的石墨毡易受腐蚀。这些问题需要持续开展研究以开发可行的解决方案。本综述全面深入地分析了电解质技术的最新进展，突出了电化学性能、稳定性和耐久性方面的改进，以及提高RFB能量和功率密度的策略。此外，它对各种三维（3D）电极材料进行了分类，包括泡沫、生物质和电纺纤维，并研究了它们的结构和成分改性如何促进钒氧化还原液流电池（VRFB）中传质的改善以及增加氧化还原反应的活性位点。通过探索创新的电极设计和功能增强，本综述旨在推进3D电极的概念化和实际应用，以优化RFB性能用于大规模储能解决方案。
