Neutral aqueous electrolytes have been shown to extend both the calendar life and cycling stability of secondary zinc–air batteries (ZABs). Despite this promise, there are currently no modeling studies investigating the performance of neutral ZABs. Traditional continuum models are numerically insufficient to simulate the dynamic behavior of these complex systems because of the rapid, orders‐of‐magnitude concentration shifts that occur. In this work, we present a novel framework for modeling the cell‐level performance of pH‐buffered aqueous electrolytes. We apply our model to conduct the first continuum‐scale simulation of secondary ZABs using aqueous ZnCl2–NH4Cl as electrolyte. We first use our model to interpret the results of two recent experimental studies of neutral ZABs, showing that the stability of the pH value is a significant factor in cell performance. We then optimize the composition of the electrolyte and the design of the cell considering factors including pH stability, final discharge product, and overall energy density. Our simulations predict that the effectiveness of the pH buffer is limited by slow mass transport and that chlorine‐containing solids may precipitate in addition to ZnO.

The development of new batteries has historically been achieved through discovery and development cycles based on the intuition of the researcher, followed by experimental trial and error—often helped along by serendipitous breakthroughs. Meanwhile, it is evident that new strategies are needed to master the ever‐growing complexity in the development of battery systems, and to fast‐track the transfer of findings from the laboratory into commercially viable products. This review gives an overview over the future needs and the current state‐of‐the art of five research pillars of the European Large‐Scale Research Initiative BATTERY 2030+, namely 1) Battery Interface Genome in combination with a Materials Acceleration Platform (BIG‐MAP), progress toward the development of 2) self‐healing battery materials, and methods for operando, 3) sensing to monitor battery health. These subjects are complemented by an overview over current and up‐coming strategies to optimize 4) manufacturability of batteries and efforts toward development of a circular battery economy through implementation of 5) recyclability aspects in the design of the battery.

This paper presents a combined theoretical and experimental investigation of aqueous nearneutral electrolytes based on chloride salts for rechargeable zinc-air batteries (ZABs). The resilience of near-neutral chloride electrolytes in air could extend ZAB lifetime, but theory-based simulations predict that such electrolytes are vulnerable to other challenges including pH instability and the unwanted precipitation of mixed zinc hydroxide chloride products. In this work, we combine theory-based simulations with experimental methods such as full cell cycling, operando pH measurements, ex-situ XRD, SEM, and EDS characterization to investigate the performance of ZABs with aqueous chloride electrolytes. The experimental characterization of near-neutral ZAB cells observes the predicted pH instability and confirms the composition of the final discharge products. Steps to promote greater pH stability and control the precipitation of discharge products are proposed. IntroductionRechargeable zinc-air batteries (ZABs) are a promising post-Lithium-Ion battery technology 1-3 for applications ranging from renewable energy storage, to electric vehicles 4 and flexible electronics 5 . Current state-of-the-art ZABs feature an alkaline electrolyte like KOH for its high conductivity, good electrochemical reaction kinetics, and moderate Zn solubility 6,7 . Unfortunately, the absorption of CO 2 from air into the electrolyte leads to the parasitic formation of carbonates (CO 2 -3 ), which slowly poisons the electrolyte 8,9 . For this reason, the lifetime of alkaline ZABs is cut short by a few weeks of continuous exposure to air.Engineering solutions to the carbonation challenge have been proposed 10 . The use of CO 2 filters to scrub the feed-gas could delay the onset of carbonation 11 , but to reach competitive lifetimes, the CO 2 concentration would need to be reduced by two ordersof-magnitude 8 . Mechanically rechargeable Zn-air fuel cells and Zn-air flow batteries, in which the electrolyte is routinely replaced, have also been demonstrated 12-17 . These solutions are effective for some applications, but they add cost and complex-Aqueous electrolytes with near-neutral pH values are resilient towards carbonation and could improve ZAB lifetime 18 . The most common near-neutral electrolyte (NNE) is ZnCl 2 −NH 4 Cl, which has been used in zinc-based LeClanché batteries for over 100 years 19,20 . In this tradition, we refer to zinc-air batteries with aqueous ZnCl 2 −NH 4 Cl as LeClanché zinc-air batteries (L-ZABs).The L-ZAB concept was first proposed in the 1970s 21 , but it has only recently become a broadly pursued topic in industry and research. Start-up companies are beginning to commercialize L-ZAB technology for grid-scale stationary applications 22 , and recent experimental research 23,24 has verified the favorable cycling stability and lifetime of these systems. Although the future of L-ZABs is hopeful, there are some factors limiting their further development.We recently performed a theoretical investigation of L-ZAB cell operatio...

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Abstract:The advent of large-scale renewable energy generation and electric mobility is driving a growing need for new electrochemical energy storage systems. Metal-air batteries, particularly zinc-air, are a promising technology that could help address this need. While experimental research is essential, it can also be expensive and time consuming. The utilization of well-developed theory-based models can improve researchers' understanding of complex electrochemical systems, guide development, and more efficiently utilize experimental resources. In this paper, we review the current state of metal-air batteries and the modeling methods that can be implemented to advance their development. Microscopic and macroscopic modeling methods are discussed with a focus on continuum modeling derived from non-equilibrium thermodynamics. An applied example of zinc-air battery engineering is presented.

This roadmap presents the transformational research ideas proposed by “BATTERY 2030+,” the European large‐scale research initiative for future battery chemistries. A “chemistry‐neutral” roadmap to advance battery research, particularly at low technology readiness levels, is outlined, with a time horizon of more than ten years. The roadmap is centered around six themes: 1) accelerated materials discovery platform, 2) battery interface genome, with the integration of smart functionalities such as 3) sensing and 4) self‐healing processes. Beyond chemistry related aspects also include crosscutting research regarding 5) manufacturability and 6) recyclability. This roadmap should be seen as an enabling complement to the global battery roadmaps which focus on expected ultrahigh battery performance, especially for the future of transport. Batteries are used in many applications and are considered to be one technology necessary to reach the climate goals. Currently the market is dominated by lithium‐ion batteries, which perform well, but despite new generations coming in the near future, they will soon approach their performance limits. Without major breakthroughs, battery performance and production requirements will not be sufficient to enable the building of a climate‐neutral society. Through this “chemistry neutral” approach a generic toolbox transforming the way batteries are developed, designed and manufactured, will be created.

As the world races to respond to the diverse and expanding demands for electrochemical energy storage solutions, lithium-ion batteries (LIBs) remain the most advanced technology in the battery ecosystem. Even as unprecedented demand for state-of-the-art batteries drives gigascale production around the world, there are increasing calls for next-generation batteries that are safer, more affordable, and energy-dense. These trends motivate the intense pursuit of battery manufacturing processes that are cost effective, scalable, and sustainable. The digital transformation of battery manufacturing plants can help meet these needs. This review provides a detailed discussion of the current and nearterm developments for the digitalization of the battery cell manufacturing chain and presents future perspectives in this field. Current modelling approaches are reviewed, and a discussion is presented on how these elements can be combined with data acquisition instruments and communication protocols in a framework for building a digital twin of the battery manufacturing chain. The challenges and emerging techniques provided here is expected to give scientists and engineers from both industry and academia a guide toward more intelligent and interconnected battery manufacturing processes in the future.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/aenm.202102696.

Aqueous zinc–air batteries (ZABs) are a low‐cost, safe, and sustainable technology for stationary energy storage. ZABs with pH‐buffered near‐neutral electrolytes have the potential for longer lifetime compared to traditional alkaline ZABs due to the slower absorption of carbonates at nonalkaline pH values. However, existing near‐neutral electrolytes often contain halide salts, which are corrosive and threaten the precipitation of ZnO as the dominant discharge product. This paper presents a method for designing halide‐free aqueous ZAB electrolytes using thermodynamic descriptors to computationally screen components. The dynamic performance of a ZAB with one possible halide‐free aqueous electrolyte based on organic salts is simulated using an advanced method of continuum modeling, and the results are validated by experiments. X‐ray diffraction, scanning electron microscopy, and energy dispersive X‐ray spectroscopy measurements of Zn electrodes show that ZnO is the dominant discharge product, and operando pH measurements confirm the stability of the electrolyte pH during cell cycling. Long‐term full cell cycling tests are performed, and rotating ring disk electrode measurements elucidate the mechanism of oxygen reduction reaction and oxygen evolution reaction. The analysis shows that aqueous electrolytes containing organic salts could be a promising field of research for zinc‐based batteries, due to their Zn2+ chelating and pH buffering properties. The remaining challenges including the electrochemical stability of the electrolyte components are discussed.