Host‐guest interactions are an attractive approach to design redox electrolytes, enabling to precisely tune the key properties for redox flow batteries such as half‐cell redox potential, solubility, and stability. Herein we report a host‐guest complex of highly water soluble (2‐hydroxypropyl)‐β‐cyclodextrin with 1‐decyl‐1′‐ethyl‐4,4′‐bipyridinium dibromide as anolyte in a new aqueous organic redox flow battery (AORFB). The supramolecular anolyte ensured the total RFB voltage increase of ≈9 % up to 0.97 V and provided a stable capacity delivery for more than 500 cycles with a capacity fade rate of 0.037 %/cycle (2.84 %/day) at high Coulombic (>99.5 %) and energy (>62 %) efficiencies. The results highlight host‐guest interactions as promising strategy towards more effective storage of renewable energy within AORFBs.

Renewable energy sources have been a topic of ever-increasing interest, not least due to escalating environmental changes. The significant rise of research into energy harvesting and storage over the years has yielded a plethora of approaches and methodologies, and associated reviews of individual aspects thereof. Here, we aim at highlighting a rather new avenue within the field of batteries, the (noaqueous) all-organic redox-flow battery, albeit seeking to provide a comprehensive and wide-ranging overview of the subject matter that covers all associated aspects. This way, subject matter on a historical perspective, general types of redox-flow cells, electrolyte design and function, flow kinetics, and cell design are housed within one work, providing perspective on the all-organic redox-flow battery in a broader sense.

The continuously increased demand for electrical energy and the associated strong growth in renewable energy necessitate robust, sustainable, and cost‐effective stationary energy storage solutions. This review paper evaluates zinc‐based batteries as viable alternatives to conventional lithium‐ion and vanadium redox flow systems for stationary storage applications. Highlighting zinc's accessibility, cost‐effectiveness, lower environmental impact, and well‐developed recycling infrastructure, this review provides a comprehensive analysis of various zinc battery chemistries, including zinc‐metal, zinc‐air, and zinc redox flow batteries. The study provides a historical context of zinc battery development from primary to secondary cells while identifying key challenges, such as low cell voltage, dendrite formation, passivation, and hydrogen evolution. Current advancements in electrode design, including novel 3D architectures, tailored electrolyte formulations, and optimized catalyst development, are discussed in detail. Additionally, a techno‐economic analysis compares material costs and operational efficiencies of zinc systems with state‐of‐the‐art alternatives, underscoring their competitive advantage. The interplay between material properties and system performance is also addressed, offering insights into improving cycling stability and energy density. Overall, this review describes the potential to position zinc batteries as promising candidates for large‐scale, sustainable energy storage, capable of complementing and potentially replacing existing technologies in an evolving energy landscape.

Each battery cell consists of three main components: the anode, the cathode, and the separator soaked with liquid electrolyte, the medium in the battery that allows charged ions to move between the two electrodes. Besides a wide electrochemical stability window and good compatibility with both electrodes, the electrolyte should also be safe, thermally stable and environmentally benign, showing a high ionic conductivity of the charge-carrying Li ions and finally a low price. This unique combination of properties is impossible to achieve with a simple salt–solvent mixture and usually requires a combination of different electrolyte components, i.e., several liquid solvents and additives and one or more conducting salt(s). For lithium-based batteries, which are the most common electrochemical energy storage devices today, a solution based on lithium hexafluorophosphate (LiPF₆) in a mixture of organic carbonates as the solvent is used. Usually, the conducting salt concentrations used for lithium-based electrolytes are in the range of ≈1 to 1.2 M, but recently, electrolytes with much higher conducting salt concentrations of 5 M and even over 10 M have been investigated as they offer several benefits ranging from increased safety to a broadened electrochemical stability window, thus enabling cheap and safe solvents, even water.