RT info:eu-repo/semantics/article T1 Mediated Alkaline Flow Batteries: From Fundamentals to Application A1 Páez, Teresa A1 Martínez Cuezva, Alberto A1 Palma, Jesús A1 Ventosa Arbaizar, Edgar K1 Energy storage K1 Batteries K1 Redox mediators K1 Energy density K1 Ferrocyanide K1 Química analítica K1 Chemistry, Analytic AB Alkaline flow batteries are attracting increasing attention for stationary energy storage. Very promising candidates have been proposed as active species for the negative compartment, while potassium ferrocyanide (K4Fe(CN)6) has been the only choice for the positive one. The energy density of this family of batteries is limited by the low solubility of K4Fe(CN)6 in alkaline media. Herein, we propose a general strategy to increase the energy density of this family of alkaline flow batteries by storing energy in commercial Ni(OH)2 electrodes confined in the positive reservoir. In this way, K4Fe(CN)6 dissolved in the electrolyte acts not only as electroactive species but also as charge carrier between current collector and solid Ni(OH)2 particles located in an external reservoir. A storage capacities of 29 Ah L–1 for the positive compartment is demonstrated. The concept is implemented in three systems, Zn–K4Fe(CN)6, anthraquinone–K4Fe(CN)6, and phenazine–K4Fe(CN)6 alkaline flow battery, showing the versatility of the strategy. Challenges and future directions to exceed the 16 Wh Ltotal–1 demonstrated in this work are discussed. PB American Chemical Society SN 2574-0962 YR 2019 FD 2019-11 LK http://hdl.handle.net/10259/6983 UL http://hdl.handle.net/10259/6983 LA eng NO Comunidad de Madrid in the Framework of the Talent Attraction Programme (Grant 2017-T1/AMB-5190) and the Spanish Ministry of Science, Innovation and Universities in the Framework of the Research Challenges Programme (Grant RTI2018-099228-A-I00) is gratefully acknowledged. A.M.-C. thanks Ministerio de Ciencia, Innovación y Universidades for a Ramon y Cajal contract and funding (Grant RYC-2017-22700). DS Repositorio Institucional de la Universidad de Burgos RD 21-nov-2024