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Non-flow aqueous zinc-bromine batteries without auxiliary components (e.g., pumps, pipes, storage tanks) and ion-selective membranes represent a cost-effective and promising technology for large-scale energy storage. Unfortunately, they generally suffer from serious diffusion and shuttle of polybromide (Br−, Br3−) due to the weak physical adsorption between soluble polybromide and host carbon materials, which results in low energy efficiency and poor cycling stability. Here, we develop a novel self-capture organic bromine material (1,1′-bis [3-(trimethylammonio)propyl]-4,4′-bipyridinium bromine, NVBr4) to successfully realize reversible solid complexation of bromide components for stable non-flow zinc-bromine battery applications. The quaternary ammonium groups (NV4+ ions) can effectively capture the soluble polybromide species based on strong chemical interaction and realize reversible solid complexation confined within the porous electrodes, which transforms the conventional “liquid–liquid” conversion of soluble bromide components into “liquid–solid” model and effectively suppresses the shuttle effect. Thereby, the developed non-flow zinc-bromide battery provides an outstanding voltage platform at 1.7 V with a notable specific capacity of 325 mAh g−1NVBr4 (1 A g−1), excellent rate capability (200 mAh g−1NVBr4 at 20 A g−1), outstanding energy density of 469.6 Wh kg−1 and super-stable cycle life (20,000 cycles with 100% Coulombic efficiency), which outperforms most of reported zinc-halogen batteries. Further mechanism analysis and DFT calculations demonstrate that the chemical interaction of quaternary ammonium groups and bromide species is the main reason for suppressing the shuttle effect. The developed strategy can be extended to other halogen batteries to obtain stable charge storage.

Abstract Aqueous Zn-I flow batteries utilizing low-cost porous membranes are promising candidates for high-power-density large-scale energy storage. However, capacity loss and low Coulombic efficiency resulting from polyiodide cross-over hinder the grid-level battery performance. Here, we develop colloidal chemistry for iodine-starch catholytes, endowing enlarged-sized active materials by strong chemisorption-induced colloidal aggregation. The size-sieving effect effectively suppresses polyiodide cross-over, enabling the utilization of porous membranes with high ionic conductivity. The developed flow battery achieves a high-power density of 42 mW cm−2 at 37.5 mA cm−2 with a Coulombic efficiency of over 98% and prolonged cycling for 200 cycles at 32.4 Ah L−1 posolyte (50% state of charge), even at 50 °C. Furthermore, the scaled-up flow battery module integrating with photovoltaic packs demonstrates practical renewable energy storage capabilities. Cost analysis reveals a 14.3 times reduction in the installed cost due to the applicability of cheap porous membranes, indicating its potential competitiveness for grid energy storage.

Abstract The high redox potential of Zn0/2+ leads to low voltage of Zn batteries and therefore low energy density, plaguing deployment of Zn batteries in many energy-demanding applications. Though employing high-voltage cathode like spinel LiNi0.5Mn1.5O4 can increase the voltages of Zn batteries, Zn2+ ions will be immobilized in LiNi0.5Mn1.5O4 once intercalated, resulting in irreversibility. Here, we design a polymer hetero-electrolyte consisting of an anode layer with Zn2+ ions as charge carriers and a cathode layer that blocks the Zn2+ ion shuttle, which allows separated Zn and Li reversibility. As such, the Zn‖LNMO cell exhibits up to 2.4 V discharge voltage and 450 stable cycles with high reversible capacity, which are also attained in a scale-up pouch cell. The pouch cell shows a low self-discharge after resting for 28 days. The designed electrolyte paves the way to develop high-voltage Zn batteries based on reversible lithiated cathodes.

Ammonia (NH3) is an ideal green fuel with high energy density and plays an indispensable role in fertilizer production. Electrochemical reduction of nitrate (NO3–), a toxic pollutant in groundwater, has shown promising as a viable approach to converting waste into valuable NH3 under ambient conditions, offering an alternative to the energy-intensive Haber-Bosch process. Due to their high efficiency, copper (Cu)-based materials have shown great potential as electrocatalysts for the NO3– reduction reaction (NO3–RR) to NH3. In this review, we provide a comprehensive summary of the fundamental principles underlying nitrate reduction over Cu-based electrocatalysts and discuss various strategies to enhance the performance of NO3– reduction, including facets, morphologies, size, surface functionalization, compositional engineering, and defect engineering. We also delve into the relationship between the electrocatalytic performance and structure characteristics of electrocatalysts and thoroughly examine the reaction mechanism involved in NO3–RR. Furthermore, we highlight the existing challenges and prospective paths forward in this area of study. This review offers valuable insights and guidance for the strategic design and optimization of Cu-based electrocatalysts for NO3–RR applications.

Objective: We have developed a baroreceptor-inspired microneedle skin patch for pressure-controlled drug release. Impact Statement: This design is inspired by the skin baroreceptors, which are mechanosensitive elements of the peripheral nervous system. We adopt the finger touching to trigger the electric stimulation, ensuring a fast-response and user-friendly administration with potentially minimal off-target effects. Introduction: Chronic skin diseases bring about large, recurrent skin damage and often require convenient and timely transdermal treatment. Traditional methods lack spatiotemporal controllable dosage, leaving a risk of skin irritation or drug resistance issues. Methods: The patch consists of drug-containing microneedles and stretchable electrode array. The electrode array, integrated with the piezoconductive switch and flexible battery, provides a mild electric current only at the spot that is pressed. Drugs in microneedles will then flow along the current into the skin tissues. The stretchable feature also provides the mechanical robustness and electric stability of the device on large skin area. Results: This device delivers Cy3 dye in pig skin with spatiotemporally controlled dosage, showing ~8 times higher fluorescence intensity than the passive delivery. We also deliver insulin and observe the reduction of the blood glucose level in the mouse model upon pressing. Compared with passive delivery without pressing, the dosage of drugs released by the simulation is 2.83 times higher. Conclusion: This baroreceptor-inspired microneedle skin patch acts as a good example of the biomimicking microneedle device in the precise control of the drug release profile at the spatiotemporal resolution.

Abstract Zn‐ion batteries are regarded as the most promising batteries for next‐generation, large‐scale energy storage because of their low cost, high safety, and eco‐friendly nature. The use of aqueous electrolytes results in poor reversibility and leads to many challenges related to the Zn anode. Electrolyte additives can effectively address many such challenges, including dendrite growth and corrosion. This review provides a comprehensive introduction to the major challenges in and current strategies used for Zn anode protection. In particular, an in‐depth and fundamental understanding is provided of the various functions of electrolyte additives, including electrostatic shielding, adsorption, in situ solid electrolyte interphase formation, enhancing water stability, and surface texture regulation. Potential future research directions for electrolyte additives used in aqueous Zn‐ion batteries are also discussed.

Because of their high safety, low cost, and high volumetric specific capacity, zinc-ion batteries (ZIBs) are considered promising next-generation energy storage devices, especially given their high potential for large-scale energy storage. Despite these advantages, many problems remain for ZIBs—such as Zn dendrite growth, hydrogen evolution, and Zn anode corrosion—which significantly reduce the coulomb efficiency and reversibility of the battery and limit its cycle lifespan, resulting in much uncertainty in terms of its practical applications. Numerous electrolyte additives have been proposed in recent years to solve the aforementioned problems. This review focuses on electrolyte additives and discusses the different substances employed as additives to overcome the problems by altering the Zn ^2+ solvation structure, creating a protective layer at the anode–electrolyte interface, and modulating the Zn ^2+ distribution to be even and Zn deposition to be uniform. On the basis of the review, the possible research strategies, future directions of electrolyte additive development, and the existing problems to be solved are also described.

The fine regulation of catalysts by the atomic-level removal of inactive atoms can promote the active site exposure for performance enhancement, whereas suffering from the difficulty in controllably removing atoms using current micro/nano-scale material fabrication technologies. Here, we developed a surface atom knockout method to promote the active site exposure in an alloy catalyst. Taking Cu3Pd alloy as an example, it refers to assemble a battery using Cu3Pd and Zn as cathode and anode, the charge process of which proceeds at about 1.1 V, equal to the theoretical potential difference between Cu2+/Cu and Zn2+/Zn, suggesting the electricity-driven dissolution of Cu atoms. The precise knockout of Cu atoms is confirmed by the linear relationship between the amount of the removed Cu atoms and the battery cumulative specific capacity, which is attributed to the inherent atom-electron-capacity correspondence. We observed the surface atom knockout process at different stages and studied the evolution of the chemical environment. The alloy catalyst achieves a higher current density for oxygen reduction reaction compared to the original alloy and Pt/C. This work provides an atomic fabrication method for material synthesis and regulation toward the wide applications in catalysis, energy, and others. [ABSTRACT FROM AUTHOR]