Constructing static two-electron lithium-bromide battery.

Despite their potential as conversion-type energy storage technologies, the performance of static lithium-bromide (SLB) batteries has remained stagnant for decades. Progress has been hindered by the intrinsic liquid-liquid redox mode and single-electron transfer of these batteries. Here, we developed a high-performance SLB battery based on the active bromine salt cathode and the two-electron transfer chemistry with a Br-/Br+ redox couple by electrolyte tailoring. The introduction of NO3- improved the reversible single-electron transition of Br-, and more impressively, the coordinated Cl- anions activated the Br+ conversion to provide an additional electron transfer. A voltage plateau was observed at 3.8 V, and the discharge capacity and energy density were increased by 142 and 159% compared to the one-electron reaction benchmark. This two-step conversion mechanism exhibited excellent stability, with the battery functioning for 1000 cycles. These performances already approach the state of the art of currently established Li-halogen batteries. We consider the established two-electron redox mechanism highly exemplary for diversified halogen batteries.

Regulating Protons to Tailor the Enol Conversion of Quinone for High-Performance Aqueous Zinc Batteries.

Quinone-based electrodes using carbonyl redox reactions are promising candidates for aqueous energy storage due to their high theoretical specific capacity and high-rate performance. However, the proton storage manners and their influences on the electrochemical performance of quinone are still not clear. Herein, we reveal that proton storage could determine the products of the enol conversion and the electrochemical stability of the organic electrode. Specifically, the protons preferentially coordinated with the prototypical pyrene-4,5,9,10-tetraone (PTO) cathode, and increasing the proton concentration in the electrolyte can improve its working potentials and cycling stability by tailoring the enol conversion reaction. We also found that exploiting Al2(SO4)3 as a pH buffer can increase the energy density of the Zn||PTO batteries from 242.8 to 284.6 Wh kg-1. Our research has a guiding significance for emphasizing proton storage of organic electrodes based on enol conversion reactions and improving their electrochemical performance.

Starch-mediated colloidal chemistry for highly reversible zinc-based polyiodide redox flow batteries.

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-1posolyte (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.

Metformin plus L-carnitine enhances brown/beige adipose tissue activity via Nrf2/HO-1 signaling to reduce lipid accumulation and inflammation in murine obesity.

This study investigated how Metformin (Met) combined with L-carnitine (L-car) modulates brown adipose tissue (BAT) to affect obesity. High-fat-induced obese rats received daily oral gavage with Met and/or L-car, followed by serum biochemical analysis, histopathological observation on adipose tissues, and immunochemistry test for the abdominal expression of BAT-specific uncoupling protein 1 (UCP1). Mouse-embryonic-fibroblast cells were induced into adipocytes, during which Met plus L-car was added with/without saturated fatty acid (SFA). The role of nuclear factor erythroid 2-related factor 2 (Nrf2) in adipocyte browning was investigated by gene silencing. Mitochondria biogenesis in adipocytes was inspected by Mitotracker staining. Nrf2/heme oxygenase-1 (HO-1)/BAT-related genes/proinflammatory marker expressions in adipose tissues and/or adipocytes were analyzed by Western blot, qRT-PCR, and/or immunofluorescence test. Met or L-car improved metabolic disorders, reduced adipocyte vacuolization and swelling, upregulated levels of BAT-related genes including UCP1 and downregulated proinflammatory marker expressions, and activated the Nrf2/HO-1 pathway in adipose tissues of obese rats. Met and L-car functioned more strongly than alone. In adipocytes, Met plus L-car upregulated BAT-related gene levels and protected against SFA-caused inflammation promotion and mitochondria degeneration, which yet was attenuated by Nrf2 silencing. Met plus L-car enhances BAT activity and white adipose tissue browning via the Nrf2/HO-1 pathway to reduce lipid accumulation and inflammation in obese rats.

Development of Inverse-Opal-Structured Charge-Deficient Co9S8@nitrogen-Doped-Carbon to Catalytically Enable High Energy and High Power for the Two-Electron Transfer I+/I- Electrode.

The iodine (I) electrode involving two-electron transfer chemistry by converting between I+ and I-, has the potential to deliver theoretically doubled capacity and higher working voltage platforms, thus achieving higher energy density. However, owing to the slow kinetics of the cascade two-electron transfer reactions, the system suffers from large overpotentials and low power density, especially at high working currents and low temperatures. Here, an inverse-opal-structured cobalt sulfide@nitrogen-doped-carbon (Co9S8@NC) catalyst with unique charge-deficient states is developed to promote the reaction kinetics of the I-/I+ electrode. The charge-deficient Co9S8@NC catalyst not only enables strong physicochemical adsorption with the iodine species but also significantly reduces the activation energy and interfacial charge transfer resistance of the cascade I+/I0/I- conversion reaction. Consequently, the prototypical Zn‖I+/I0/I- battery equipped with the Co9S8@NC catalyst can deliver a high energy density of 554 Wh kg-1 and a stable cycle life of 5000 cycles at 30 °C. Moreover, at a subzero temperature of -30 °C, the battery can exhibit enhanced kinetics and a high power density of 1514 W kg-1, high energy density of 485 Wh kg-1.

Rational Design of Dynamically Super-Tough and Super-Stretchable Hydrogels for Deformable Energy Storage Devices.

Hydrogels possess unique polymer networks that offer flexibility/stretchability, high ionic conductivity, and resistance to electrolyte leakage, making them suitable for deformable energy storage devices. Endowing the mechanical functionality of the hydrogel electrolytes focus on either enhancing the stretchability or the toughness. However, the stretchability and the toughness are generally a trade-off that the stretchable gels are intrinsically prone to damage and sensitive to notches and cracks. Here, the regulating strategies on the hydrogel's mechanical properties are provided to develop the designated hydrogel electrolyte, where different polymeric network structures are constructed, including single network structures, semi-interpenetrating network structures, and interpenetrating dual-network structures. A comprehensive comparison of these polymer network structures is conducted to evaluate their mechanical stretchability and toughness. Designing super-tough and super-stretchable hydrogels based on specific application requirements can be realized by striking a balance by regulating the hydrogel structure. In specific, incorporating semi-interpenetrating networks significantly can enhance stretchability to achieve a break elongation up to 1300%, while the interpenetrating dual-networks can largely improve the toughness to realize the extraordinary fracture toughness of 6.843 kJ m-2 . These findings offer valuable designing guidance for designated hydrogel electrolytes and the deformable zinc-silver battery is demonstrated with high mechanical stability and electrochemical performance.

Perovskite Cathodes for Aqueous and Organic Iodine Batteries Operating Under One and Two Electrons Redox Modes.

Although conversion-type iodine-based batteries are considered promising for energy storage systems, stable electrode materials are scarce, especially for high-performance multi-electron reactions. The use of tin-based iodine-rich 2D Dion-Jacobson (DJ) ODASnI4 (ODA: 1,8-octanediamine) perovskite materials as cathode materials for iodine-based batteries is suggested. As a proof of concept, organic lithium-perovskite and aqueous zinc-perovskite batteries are fabricated and they can be operated based on the conventional one-electron and advanced two-electron transfer modes. The active elemental iodine in the perovskite cathode provides capacity through a reversible I- /I+ redox pair conversion at full depth, and the rapid electron injection/extraction leads to excellent reaction kinetics. Consequently, high discharge plateaus (1.71 V vs Zn2+ /Zn; 3.41 V vs Li+ /Li), large capacity (421 mAh g-1 I ), and a low decay rate (1.74 mV mAh-1 g-1 I ) are achieved for lithium and zinc ion batteries, respectively. This study demonstrates the promising potential of perovskite materials for high-performance metal-iodine batteries. Their reactions based on the two-electron transfer mechanism shed light on similar battery systems aiming for decent operational stability and high energy density.

Deploying Cationic Cellulose Nanofiber Confinement to Enable High Iodine Loadings Towards High Energy and High-Temperature Zn-I2 Battery.

High iodine loading and high-temperature adaptability of the iodine cathode are prerequisites to achieving high energy density at full battery level and promoting the practical application for the zinc-iodine (Zn-I2 ) battery. However, it would aggravate the polyiodide shuttle effect when employing high iodine loading and working temperature. Here, a sustainable cationic cellulose nanofiber (cCNF) was employed to confine the active iodine species through strong physiochemical adsorption to enlarge the iodine loading and stabilize it even at high temperatures. The cCNF could accommodate dual-functionality by enlarging the iodine loading and suppressing the polyiodide shuttle effect, owing to the unique framework structure with abundant surface positive charges. As a result, the iodine cathode based on the cCNF could deliver high iodine mass loading of 14.1 mg cm-2 with a specific capacity of 182.7 mAh g-1 , high areal capacity of 2.6 mAh cm-2 , and stable cycling over 3000 cycles at 2 A g-1 , thus enabling a high energy density of 34.8 Wh kg-1 and the maximum power density of 521.2 W kg-1 at a full Zn-I2 battery level. In addition, even at a high temperature of 60 °C, the Zn-I2 battery could still deliver a stable cycling.

Electrolyte Additives for Stable Zn Anodes.

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.

Electrochemical nitrate reduction in acid enables high-efficiency ammonia synthesis and high-voltage pollutes-based fuel cells.

Most current research is devoted to electrochemical nitrate reduction reaction for ammonia synthesis under alkaline/neutral media while the investigation of nitrate reduction under acidic conditions is rarely reported. In this work, we demonstrate the potential of TiO2 nanosheet with intrinsically poor hydrogen-evolution activity for selective and rapid nitrate reduction to ammonia under acidic conditions. Hybridized with iron phthalocyanine, the resulting catalyst displays remarkably improved efficiency toward ammonia formation owing to the enhanced nitrate adsorption, suppressed hydrogen evolution and lowered energy barrier for the rate-determining step. Then, an alkaline-acid hybrid Zn-nitrate battery was developed with high open-circuit voltage of 1.99 V and power density of 91.4 mW cm-2. Further, the environmental sulfur recovery can be powered by above hybrid battery and the hydrazine-nitrate fuel cell can be developed for simultaneously hydrazine/nitrate conversion and electricity generation. This work demonstrates the attractive potential of acidic nitrate reduction for ammonia electrosynthesis and broadens the field of energy conversion.

Crystal Orientation Engineering of Perfectly Matched Heterogeneous Textured ZnSe for an Enhanced Interfacial Kinetic Zn Anode.

Uncontrollable dendrite formation in the Zn anode is the bottleneck of the commercialization of rechargeable aqueous zinc-based batteries (RAZBs). Interface, the location of the charge transfer process occuring, can significantly affect the further morphology evolution in ways that have not yet been fully comprehended, for example, the crystal facet and orientation of the coating layer. In this study, we demonstrated that the morphology and kinetics of the Zn anode could be tuned by the crystal facet. The fabricated textured ZnSe (T-ZnSe) layer can significantly enhance the reaction kinetics and induce uniform (0002)Zn deposition. In stark contrast, the polycrystalline P-ZnSe coating hinders the charge transfer process at the interface. With this T-ZnSe@Zn as the anode, the full cell with an I2 cathode and a practical areal capacity (2 mAh cm-2) can work well for 900 cycles. The effectiveness of this anode has also been testified by a pouch cell with an overall capacity of 150 mAh. This research contributes to the understanding of the interface and the feasible strategy for the practical application of the Zn anode.

Manipulating coordination environment for a high-voltage aqueous copper-chlorine battery.

Aqueous copper-based batteries have many favourable properties and have thus attracted considerable attention, but their application is limited by their low operating voltage originating from the high potential of copper negative electrode (0.34 V vs. standard hydrogen electrode). Herein, we propose a coordination strategy for reducing the intrinsic negative electrode redox potential in aqueous copper-based batteries and thus improving their operating voltage. This is achieved by establishing an appropriate coordination environment through the electrolyte tailoring via Cl- ions. When coordinated with chlorine, the intermediate Cu+ ions in aqueous electrolytes are successfully stabilized and the electrochemical process is decoupled into two separate redox reactions involving Cu2+/Cu+ and Cu+/Cu0; Cu+/Cu0 results in a redox potential approximately 0.3 V lower than that for Cu2+/Cu0. Compared to the coordination with water, the coordination with chlorine also results in higher copper utilization, more rapid redox kinetics, and superior cycle stability. An aqueous copper-chlorine battery, harnessing Cl-/Cl0 redox reaction at the positive electrode, is discovered to have a high discharge voltage of 1.3 V, and retains 77.4% of initial capacity after 10,000 cycles. This work may open up an avenue to boosting the voltage and energy of aqueous copper batteries.

Proinflammatory Bone Marrow Mesenchymal Stem Cell-Derived Exosomal miR-150-3p Suppresses Proinflammatory Polarization of Alveolar Macrophages in Sepsis by Targeting Inhibin Subunit Beta A.

Bone marrow mesenchymal stem cell (BMSC)-derived exosomes can protect lung tissues against sepsis, but its related mechanism remains elusive. BMSCs were primed with or without lipopolysaccharide (LPS) before extracting exosomes. The isolated exosomes were identified by transmission electron microscopy, nanoparticle tracking analysis, and western blot. LPS-stimulated macrophages were cocultured with exosomes for 24 h, followed by enzyme-linked immunosorbent assay, flow cytometry, and molecular experiments. Bioinformatics and luciferase assay were employed to investigate the interaction between miR-150-3p and inhibin subunit beta A (INHBA). MiR-150-3p expression was increased in exosomes in a proinflammatory environment. Exosomes suppressed proinflammatory polarization by downregulating IL-6, IL-1ß, iNOS, and CD86, as well as promoted anti-inflammatory polarization by upregulating IL-10, ARG-1, and CD206 in LPS-stimulated macrophages. Such effects were more pronounced by LPS-primed exosomes, which was reversed in the absence of miR-150-3p. MiR-150-3p targeted INHBA. INHBA silencing decreased CD86 expression and increased CD206 expression in macrophages, but these effects were reversed by exosomal miR-150-3p inhibition. Proinflammatory BMSC-derived exosomal miR-150-3p suppressed proinflammatory polarization and promoted anti-inflammatory polarization of alveolar macrophages to attenuate LPS-induced sepsis by targeting INHBA.

Tellurium with Reversible Six-Electron Transfer Chemistry for High-Performance Zinc Batteries.

Chalcogens, especially tellurium (Te), as conversion-type cathodes possess promising prospects for zinc batteries (ZBs) with potential rich valence supply and high energy density. However, the conversion reaction of Te is normally restricted to the Te2-/Te0 redox with a low voltage plateau at ∼0.59 V (vs Zn2+/Zn) rather than the expected positive valence conversion of Te0 to Ten+, inhibiting the development of Te-based batteries toward high output voltage and energy density. Herein, the desired reversible Te2-/Te0/Te2+/Te4+ redox behavior with up to six-electron transfer was successfully activated by employing a highly concentrated Cl--containing electrolyte (Cl- as strong nucleophile) for the first time. Three flat discharge plateaus located at 1.24, 0.77, and 0.51 V, respectively, are attained with a total capacity of 802.7 mAh g-1. Furthermore, to improve the stability of Ten+ products and enhance the cycling stability, a modified ionic liquid (IL)-based electrolyte was fabricated, leading to a high-performance Zn∥Te battery with high areal capacity (7.13 mAh cm-2), high energy density (542 Wh kgTe-1 or 227 Wh Lcathdoe+anode-1), excellent cycling performance, and a low self-discharge rate based on 400 mAh-level pouch cell. The results enhance the understanding of tellurium chemistry in batteries, substantially promising a remarkable route for advanced ZBs.

Three-Electron Transfer-Based High-Capacity Organic Lithium-Iodine (Chlorine) Batteries.

Conversion-type batteries apply the principle that more charge transfer is preferable. The underutilized electron transfer mode within two undermines the electrochemical performance of halogen batteries. Here, we realised a three-electron transfer lithium-halogen battery based on I- /I+ and Cl- /Cl0 couples by using a common commercial electrolyte saturated with Cl- anions. The resulting Li||tetrabutylammonium triiodide (TBAI3 ) cell exhibits three distinct discharging plateaus at 2.97, 3.40, and 3.85 V. Moreover, it has a high capacity of 631 mAh g-1 I (265 mAh g-1 electrode , based on entire mass loading) and record-high energy density of up to 2013 Wh kg-1 I (845 Wh kg-1 electrode ). To support these findings, experimental characterisations and density functional theory calculations were conducted to elucidate the redox chemistry involved in this novel interhalogen strategy. We believe our paradigm presented here has a foreseeable inspiring effect on other halogen batteries for high-energy-density pursuit.

Spider Silk-Inspired Binder Design for Flexible Lithium-Ion Battery with High Durability.

The development of flexible lithium-ion batteries (LIBs) imposes demands on energy density and high mechanical durability simultaneously. Due to the limited deformability of electrodes, as well as the flat and smooth surface of the metal current collectors, stable/durable/reliable contact between electrode materials and the current collectors remains a challenge, in particular, for electrodes with high loading mass and heavily deformed batteries. Binders play an essential role in binding particles of electrode materials and adhering them to current collectors. Herein, inspired by spider silk, a binder for flexible LIBs is developed, which equips a cross-linked supramolecular poly(urethane-urea) to the polyacrylic acid. The binder imparts super high elastic restorability originating from the meticulously engineered hydrogen-bonding segments as well as extraordinary adhesion. The developed binder provides excellent flexibility and intact electrode morphologies without disintegration even when the electrode is largely deformed, enabling a stable cycling and voltage output even when the batteries are put under tough dynamic deformation tests. The flexible LIBs exhibit a high energy density of 420 Wh L-1 , which is remarkably higher than reported numbers. The unique binder design is greatly promising and offers a valuable material solution for LIBs with high-loading mass and flexible designs.

Colloid Electrolyte with Weakly Solvated Structure and Optimized Electrode/Electrolyte Interface for Zinc Metal Batteries.

Aqueous zinc batteries are considered as a viable candidate for cost-effective and environmentally sustainable energy storage technology but are severely hampered by the notorious dendrite growth and parasitic reactions at the zinc anode side. Herein, we propose a bifunctional colloidal electrolyte design that utilizes upconversion nanocrystals, i.e., NaErF4@NaYF4, as a solid additive to provide the sustained release of functional metal and fluoride ions, which can effectively improve the reversibility of the Zn anode to inhibit dendrite growth and hydrogen evolution through forming an electrostatic shielding layer and in situ constructing a ZnF2-enriched protective interface. Experimental characterization and molecular dynamics simulation jointly confirm that the NaErF4@NaYF4 additive could modify the Zn2+ solvation environment in the vicinity of the NaErF4@NaYF4 surface via the strong electrostatic coupling with Zn2+ ions. As a consequence, the modified electrolyte enables stable zinc plating/stripping over 2100 h at a current density of 3 mA cm-2 and a capacity of 1 mAh cm-2 in symmetric cells. The assembled Zn||MnO2 full cells with a modified electrolyte can operate stably for 1600 cycles at 2 A g-1. This work thereby has great potential for the exploration of multifunctional electrolyte additives toward long-lasting aqueous Zn metal batteries.

Development of rechargeable high-energy hybrid zinc-iodine aqueous batteries exploiting reversible chlorine-based redox reaction.

The chlorine-based redox reaction (ClRR) could be exploited to produce secondary high-energy aqueous batteries. However, efficient and reversible ClRR is challenging, and it is affected by parasitic reactions such as Cl2 gas evolution and electrolyte decomposition. Here, to circumvent these issues, we use iodine as positive electrode active material in a battery system comprising a Zn metal negative electrode and a concentrated (e.g., 30 molal) ZnCl2 aqueous electrolyte solution. During cell discharge, the iodine at the positive electrode interacts with the chloride ions from the electrolyte to enable interhalogen coordinating chemistry and forming ICl3-. In this way, the redox-active halogen atoms allow a reversible three-electrons transfer reaction which, at the lab-scale cell level, translates into an initial specific discharge capacity of 612.5 mAh gI2-1 at 0.5 A gI2-1 and 25 °C (corresponding to a calculated specific energy of 905 Wh kgI2-1). We also report the assembly and testing of a Zn | |Cl-I pouch cell prototype demonstrating a discharge capacity retention of about 74% after 300 cycles at 200 mA and 25 °C (final discharge capacity of about 92 mAh).

Distinct chemistry between Zn and Li at varied temperature.

The operating temperature of batteries is an essential consideration in actual applications. Understanding the temperature dependence is conducive to battery design. The experience in lithium-ion batteries (LIBs) indicates that the dendrite issue is exacerbated at lower temperatures and suppressed at higher temperatures. In this study, we revealed the dendrite evolution in aqueous rechargeable zinc-based batteries (RZBs), for which the opposite temperature dependence was observed. Detailed investigations elucidate that the degree of matching of the interface reaction rate and ion diffusivity, together with side reactions, are the key factors that determine the cycling performance. The different properties of organic and aqueous electrolytes result in a reversed temperature dependence. We further conducted a detailed investigation of hybrid electrolytes (organic and aqueous) for balancing the ion diffusivity and side reactions to broaden the working temperature window for RZBs. This work reveals a completely opposite temperature dependence for LIBs and RZBs and discloses the underlying mechanism, reminding one of the differences between LIBs and RZBs in many aspects.

Regulating Inorganic and Organic Components to Build Amorphous-ZnFx Enriched Solid-Electrolyte Interphase for Highly Reversible Zn Metal Chemistry.

The introduction of inorganic crystallites into a solid-electrolyte interphase (SEI) is an effective strategy for improving the reversibility of the Zn metal anode (ZMA). However, the structure-performance relationship of the SEI is not fully understood because the existing forms of its inorganic and organic components in their pristine states are not resolved. Here, a highly effective SEI is constructed for ZMA using a bisolvent electrolyte and resolved its composition/structure by cryogenic transmission electron microscopy. This highly fluorinated SEI with amorphous inorganic ZnFx uniformly distributed in the organic matrix is largely different from the common mosaic and multilayer SEIs with crystalline inorganics. It features improved structural integrity, mechanical toughness, and Zn2+ ion conductivity. Consequently, the ZMA exhibits excellent reversibility with an enhanced plating/stripping Coulombic efficiency of 99.8%. The ZMA-based full cell achieves a high Zn utilization ratio of 54% at a practical areal capacity of 3.2 mAh cm-2 and stable cycling over 1800 h during which the accumulated capacity reached 5600 mAh cm-2 . This research highlights the detailed structure and composition of amorphous SEIs for highly reversible metal anodes.