Search

The intrinsically low electrical conductivity and poor structural fragility of MnO2 have significantly hampered the zinc storage performance. In this work, Ba2+-implanted δ-MnO2 nanosheets have been hydrothermally grown on a carbon cloth (Ba–MnO2@CC) as an extremely stable and efficient cathode material of aqueous zinc-ion batteries. The three-dimensionally porous architecture composed of interwoven thin MnO2 nanosheets effectively shortens the electron/ion transport distances, enlarges the electrode/electrolyte contact area, and increases the active sites for the electrochemical reaction. Meanwhile, Ba2+ could function as an interlayer pillar to stabilize the crystal structure of MnO2. Consequently, the as-optimized Ba–MnO2@CC exhibits remarkable Zn2+ storage capabilities, such as a high capacity (305 mAh g−1 at 0.2 A g−1), prolonged lifespan (95% retention after a 200-cycling test), and superb rate capability. The binder-free cathode is also applicable for flexible energy storage devices with attractive properties. The present investigation provides important insights into designing advanced cathode materials toward wearable electronics. [ABSTRACT FROM AUTHOR]

FeN 3 -CoN 3 sites break the symmetric electron distribution of single atom sites optimizing adsorption energies of oxygen intermediates. As a result, FeCo-NC exhibits extraordinary ORR activity with a high half-wave potential of 0.915 V in alkaline electrolyte. [Display omitted] Single-atom catalysts show good oxygen reduction reaction (ORR) performance in metal-air battery. However, the symmetric electron distribution results in discontented adsorption energy of ORR intermediates and a lower ORR activity. Herein, Fe-Co dual-atom catalyst with FeN 3 -CoN 3 configuration was prepared by encapsulating nitrogen-rich ion (triethylenediamine cobalt complex, [Co(en) 3 ]3+) in Fe based MOF cage to greatly enhance ORR performance. Due to the confinement effect of the MOF cage, the encapsulated [Co(en) 3 ]3+ is closer to Fe of MOF, thus easily generating FeN 3 -CoN 3 sites. The FeN 3 -CoN 3 sites can break the symmetric electron distribution of single-atom sites, optimizing adsorption energy of oxygen intermediate. Thus, FeCo-NC exhibits extraordinary ORR activity with a high half-wave potential of 0.915 V and 0.789 V in alkaline and acidic electrolyte, respectively, while it was 0.874 V and 0.79 V for Pt/C. The liquid and solid Zn-air batteries with FeCo-NC as cathode show higher peak power density and specific capacity. DFT results indicate that FeN 3 -CoN 3 site can reduce the reaction energy barrier of the rate-determining step resulting in an excellent ORR performance. [ABSTRACT FROM AUTHOR]

"Dalton Transactions: An International Journal of Inorganic Chemistry" is a publication by the Royal Society of Chemistry that features research articles on various topics in inorganic chemistry. The journal includes papers on solar energy, nanocatalysis, functional materials, and the synthesis of chemical compounds. It also covers topics such as the modification of metal ions, green synthesis methods, and the development of potential antitumor drugs. The journal aims to connect the global chemistry community and reinvest profits back into the field. [Extracted from the article]

The widespread adoption of rechargeable alkaline batteries is plagued by the performance‐limiting metal anodes, which are prone to (electro)chemical corrosion and raise environmental or economic concerns. Organic redox‐active materials offer a potential solution, but they typically struggle with dissolution‐induced degradation and insufficiently negative reduction potentials. Herein, we introduce benzo[c]cinnoline and its derivatives (collectively referred to as BCCs), a class of aromatic azo compounds with fused‐ring structure, as promising organic anode materials. BCCs exhibit pronounced aromaticity and Brønsted basicity, conferring low reduction potentials and intrinsic insolubility in alkaline solutions. Paired with the industrially established nickel hydroxide cathode, these batteries deliver excellent capacity (297 mAh g−1anode), high output voltage of 1.3 V, and extended cycle life (≈16000 cycles). Notably, they also operate efficiently at extremely low temperatures down to −85 °C with an 8 M KOH electrolyte. We further explore the feasibility for all‐organic alkaline batteries by paring BCCs with the dihydro form of 4,4’‐azopyridine, utilizing azo compounds for both anode and cathodes. This chemistry harnesses the unique properties of small organic molecules to enable all‐organic batteries with high capacity of 236 mAh g–1, fast charging at 1200 C, and easy recyclability. [ABSTRACT FROM AUTHOR]

Metal-organic framework (MOF)-based electrocatalysts often undergo structural distortion during the oxygen evolution reaction (OER), which can affect their original structure and stability, and poses challenges for theoretical analysis and mechanistic exploration. Herein, vanadium (V) was doped to construct a V–Ni MOF/NF (1.0: 10) that combines structural stability with excellent catalytic activity. The introduction of V significantly suppressed the structural distortion tendency of Ni MOF during the OER process. Additionally, V doping promoted charge redistribution, which enhanced the overall oxidation state of Ni sites and increased oxygen vacancies, providing more active sites and faster electron transport capabilities, boosting the intrinsic activity. As a result, V–Ni MOF/NF (1.0: 10) can be used as a "real catalyst" directly in alkaline OER testing and further applied to seawater splitting and Zinc-air batteries. This work is the first to propose an inhibition strategy for structural distortion of MOF-based OER catalyst, offering new insights into the development of high-activity and stable MOF-based "real catalysts". The V doping significantly inhibited the structural distortion of Ni MOF during the OER process, imparting excellent structural stability of Ni MOF and allowing it to be directly used as a "real catalyst" in electrocatalytic applications. [Display omitted] • V doping inhibited Ni MOF structural distortion during OER. • The first time to study the inhibition strategy of MOF-based OER catalyst distortion. • V–Ni MOF/NF (1.0: 10) showed superior OER activity and excellent structural stability. • V–Ni MOF/NF (1.0:10) excelled in seawater splitting devices and Zinc-air batteries. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to assess how aware European paediatricians were of the risks faced by children who swallowed button batteries and the advice for managing such cases. Methods: An Internet‐based survey was conducted among European paediatricians between 1 April 2023 and 31 May 2023. The researchers contacted members of the European Academy of Paediatrics Research in Ambulatory Setting Network and a number of European national paediatric societies. Results: Responses were received from 605 paediatricians (66.0% females) in 41 countries and 64.5% had encountered cases of button battery ingestion. Only 31.2% had received specific training and only 35.7% were familiar with the advice issued by the European Society for Paediatric Gastroenterology, Hepatology and Nutrition and the European Academy of Pediatrics. While 90.8% of respondents correctly recognised the need for hospitalisation of a child after button battery ingestion, only 30.1% of them identified all symptoms and 58.2% could accurately determine the appropriate diagnostic scope. One in ten underestimated the health or life risks. These deficiencies were significantly attributed to a lack of adequate training (p < 0.01). The overwhelming majority of the respondents expressed the need to increase awareness among physicians and childcare providers, mainly through social media campaigns and advertisements. Conclusion: European paediatricians were insufficiently aware of button battery ingestion risks and management, with significant gaps in training and familiarity with advice. Respective education for medical practitioners and raising public awareness should be markedly strengthened. [ABSTRACT FROM AUTHOR]

• Discarded alkaline batteries retain 13 % of their energy, showing reuse potential. • Study shows a 660 MWh total energy loss for all AA alkaline batteries in the U.S. • Technical challenges hinder effective reuse of partially-spent batteries. Each year, a significant number of single-use alkaline batteries with untapped energy are discarded. This study aims to analyze the usage patterns of alkaline batteries based on a dataset of 1021 used batteries, ranging from Size AA to 9V, collected from households in the State of New York. We measure the energy loss resulting from underutilized batteries and examine the corresponding environmental and economic impacts on a national scale. Discarded AA alkaline batteries maintain about 13 % of their initial energy, that results in an estimated annual energy loss of 660 MWh for all AA alkaline batteries in the U.S., and about 40 MWh in New York State. Annually in the U.S., consumers discard AA alkaline batteries with approximately $80 million worth of unused energy, including $4.8 million in New York State alone. We also show that the lifecycle impact of batteries should be multiplied by 1.25 to account for their underutilization. To address these issues, we propose actionable recommendations for improving battery consumption practices and facilitating End-of-Life/Use (EoL/U) recovery processes. The findings show the need for policy interventions to better manage battery usage and disposal toward reducing energy waste and mitigating environmental impacts. [ABSTRACT FROM AUTHOR]

The performance of zinc‐air battery is constrained by the sluggish rate of oxygen electrode reaction, particularly under high current discharge conditions where the kinetic process of the oxygen reduction reaction (ORR) decelerates significantly. To address this challenge, we present a novel phase transition strategy that facilitates the creation of a heteroatom‐doped heterointerface (CoN/CoS2). The meticulously engineered CoN/CoS2/NC electrocatalyst displays a superior ORR half‐wave potential of 0.87 V and an OER overpotential of 320 mV at 10 mA cm−2. Experimental and computational analysis confirm that the CoN/CoS2 heterostructure optimizes local charge distribution, accelerates electron transfer, and tunes active sites for enhanced catalysis. Notably, this heterojunction improves stability by resisting corrosion and degradation under harsh alkaline conditions, thus demonstrating superior performance and longevity in a custom‐made liquid zinc‐air battery. This research provides valuable practical and theoretical foundations for designing efficient heterointerfaces in electrocatalysis applications. [ABSTRACT FROM AUTHOR]

Although various bismuth (Bi) electrode materials are reported to assemble aqueous alkaline rechargeable batteries (AARBs) owing to desirable potential window and high theoretical capacity, the Bi‐based electrode materials are still confronted with by their "death space" and poor stability. Herein, a zero‐dimensional/two‐dimensional (0D/2D) amorphous/crystalline BiOx‐Bi heterostructure is successfully synthesized by a one‐step reduction method for achieving nearly theoretical capacity. Under proper NaBHNaBH4 content, the Bi33+ is reduced to form ultra‐thin 2D metallic bismuth nanoflakes (Bi‐nf), and incompletely reduced amorphous 0D BiOx nanodots are embedded in Bi‐nf to form the target BiOx/Bi‐nf heterostructure. The embedded 0D nanodots inhibit the aggregation of 2D Bi‐nf, accelerate the mass transport rate with more oxygen vacancies and pores at heterogeneous interface, and the active centers of amorphous nanodots and ultrathin nanoflakes are recognized as completely accessible which is benefit for up to theoretical capacity. Accordingly, the optimized 0D/2D amorphous/crystalline BiOx‐Bi‐nf heterostructure electrode presents an admirable capacity of 350 mAh g−1 at 1 A g−1 and outstanding capacity retention of 79.9% at 20 A g‐1. Moreover, the assembled BCNP (basic cobalt/nickel phosphate)//BiOx/Bi‐nf battery exhibits exceptional energy density of 191.64 Wh kg‐1 at 1.28 kW kg‐1 power density and durable stability (80% after 14000 cycles). [ABSTRACT FROM AUTHOR]

Rechargeable Zn-air batteries are considered to be an effective energy storage device due to their high energy density, environmental friendliness, and long operating life. Further progress on rechargeable Zn-air batteries with high energy density/power density is greatly needed to satisfy the increasing energy conversion and storage demands. This review summarizes the strategies proposed so far to pursue high-efficiency Zn-air batteries, including the aspects of the electrocatalysts (from noble metals to non-noble metals), the electrode chemistry (from the oxygen evolution reaction to the organic oxidation reaction), electrode engineering (from powdery to free-standing), aqueous electrolytes (from alkaline to non-alkaline) and the battery configuration (from liquid to flexible). An essential evaluation of electrochemistry is highlighted to solve the challenges in boosting the efficiency of rechargeable metal-air batteries. In the end, the perspective on current challenges and future research directions to promote the industrial application of rechargeable Zn-air batteries is provided. [ABSTRACT FROM AUTHOR]

In this work, we develop an in situ biomass-confined approach to fabricate an atomically dispersed Fe/NC catalyst for ORR. The acquired Fe/NC demonstrates glorious oxygen reduction reaction (ORR) activity (E1/2: 0.858 V) in alkaline media and long-term cycling stability (∼750 h) in a homemade liquid zinc-air battery. [ABSTRACT FROM AUTHOR]

[Display omitted] Exploiting highly efficient, cost-effective and stable electrocatalysts is key to decreasing hydrogen evolution reaction (HER) kinetics energy barrier. Herein, the alkaline HER kinetics energy barrier can greatly reduce by the joint strategies of the cation vacancy and heterostructure engineering, which is seldom explored and remains ambiguous. In this study, an efficient and stable copper foam-supported Cu 3 P-CoP heterostructure electrocatalyst with cation vacancy defects (defined as Cu 3 P-CoP-V Al /CF) was designed for HER via the successive coprecipitation, electrodeposition, alkali etching and phosphorization treatments. As anticipated, the as-obtained Cu 3 P-CoP-V Al /CF electrocatalyst reveals a remarkable catalytic activity for HER with a low overpotential of 205 mV at a current density of 100 mA·cm−2, a high turnover frequency value of 1.05 s−1 at an overpotential of 200 mV and a small apparent activation energy (E a) of 9 kJ·mol−1, while shows superior long-term stability at large current densities of 100 and 240 mA·cm−2. Systematic experiment and characterization data demonstrate that the formed cation vacancy could optimize the E a , leading to the decrease of the kinetic barriers of Cu 3 P-CoP/CF heterostructure, as well as the established heterogeneous interface induced a synergistic effect between biphasic components on boosting the kinetics toward HER. The results of density functional theory disclose that the synergistic effect of Cu 3 P-CoP heterostructure could decrease the energy barrier and optimize Gibbs free energy of hydrogen adsorption, resulting in the enhancement of intrinsic catalytic activity of Cu 3 P-CoP-V Al /CF. More significantly, the alkali-cell assembled by Cu 3 P-CoP-V Al /CF (cathode) and RuO 2 /CF (anode) behaves outstanding water splitting performance, delivering a current density of 10 mA·cm−2 at a relatively small applied voltage of 1.58 V, along with encouraging long-term durability. In addition, the alkaline Zn-H 2 O battery with Cu 3 P-CoP-V Al /CF as the cathode has been fabricated for the simultaneous generation of electricity and hydrogen, which displays a large power density of up to 4.1 mW·cm−2. The work demonstrates that rational strategy for the design of competent electrocatalysts can effectively accelerate the kinetics of HER, which supplies valuable insights for practical applications in overall water splitting. [ABSTRACT FROM AUTHOR]

Catalysts with atomically dispersed Fe–N 4 active sites have emerged as promising alternatives for noble-metal catalysts in oxygen reduction reaction (ORR). However, the sluggish reaction kinetics limit their further utilization. Herein, asymmetry active sites FeN 3 S 1 located on mesoporous carbon matrix (Fe–N 3 S 1 /C meso) are constructed and verified as efficient ORR catalysts with fast reaction kinetics. The synthesized Fe–N 3 S 1 /C meso catalysts exhibit a half-wave potential of 0.92 V in alkaline electrolyte, a higher power density (178 mW cm−2) and a long-term durability (350 h) in Zn-Air battery. Mechanism study demonstrates that the specific structure induces accumulated electronic density and decreased d band center of Fe atoms which optimize the adsorption energy with OH∗ intermediates thus boosting the intrinsic activity. Moreover, the uniform mesoporous structure significantly increases the accessibility of active sites. This work offers a new perspective to optimize the adsorption strength of reaction intermediates for enhanced ORR. [Display omitted] • Asymmetry active sites of Fe–N 3 S 1 located on mesoporous substrate were constructed. • The adsorption energy of oxygenated intermediates was optimized. • Mesoporous substrate possesses highly exposed sites and fast mass transportation. • Fe–N 3 S 1 /C meso catalysts exhibit superior ORR performance and long-term durability. [ABSTRACT FROM AUTHOR]

Alkaline zinc‐iron flow batteries (ZFBs) have recently attracted renewed attention. However, the critical issues with zinc anodes, such as dendrite formation, side reactions, and labile plating or stripping, have yet to be adequately addressed. Here, an attempt is made to overcome these challenges by designing Boron‐doped carbon‐felt (B–CF) electrodes rich in electron‐deficient sites and defects. The fabricated B–CF provides improved adsorption of negatively charged Zn(OH)42−, robust Zn nucleation sites, and lower Zn nucleation and deposition overpotentials, leading to homogeneous Zn deposition morphology. Uniform Zn deposition enables the prevention of undesirable dendrite growth and parasitic reactions. As a result, the constructed alkaline ZFBs achieve a high average Coulombic efficiency of ≈99.85% and energy efficiency of 88% with uniform Zn deposition during 300 cycles (40 mA cm−2). This work expands the understanding of the electrode design strategy for achieving favorable Zn plating/stripping. [ABSTRACT FROM AUTHOR]

We propose an in situ gas etching-thermal assembly strategy to simultaneously create mesopore-dominated carbon cores with ultrathin carbon-layer shells fully decorated with highly dispersed Mn-N 4 single-atom sites, which was used as a highly active and stable ORR catalyst in zinc-air batteries. [Display omitted] Applications of zinc-air batteries are partially limited by the slow kinetics of oxygen reduction reaction (ORR); Thus, developing effective strategies to address the compatibility issue between performance and stability is crucial, yet it remains a significant challenge. Here, we propose an in situ gas etching-thermal assembly strategy with an in situ -grown graphene-like shell that will favor Mn anchoring. Gas etching allows for the simultaneous creation of mesopore-dominated carbon cores and ultrathin carbon layer shells adorned entirely with highly dispersed Mn-N 4 single-atom sites. This approach effectively resolves the compatibility issue between activity and stability in a single step. The unique core–shell structure allows for the full exposure of active sites and effectively prevents the agglomerations and dissolution of Mn-N 4 sites in cores. The corresponding half-wave potential for ORR is up to 0.875 V (vs. reversible hydrogen electrode (RHE)) in 0.1 M KOH. The gained catalyst (Mn-N@Gra-L)-assembled zinc-air battery has a high peak power density (242 mW cm−2) and a durability of ∼ 115 h. Furthermore, replacing the zinc anode achieved a stable cyclic discharge platform of ∼ 20 h at varying current densities. Forming more fully exposed and stable existing Mn-N 4 sites is a governing factor for improving the electrocatalytic ORR activity, significantly cycling durability, and reversibility of zinc-air batteries. [ABSTRACT FROM AUTHOR]

In order to improve the electrochemical activity and discharge performance of aluminum–air batteries and to reduce self-corrosion of the anode, an SLM-manufactured aluminum alloy was employed as the anode of the Al-air battery, and the influence of PAAS and ZnO inhibitors taken separately or together on the self-corrosion rate and discharge performance of the Al-air battery in a 4 M NaOH solution were investigated. The experimental result indicated that the effect of a composite corrosion inhibitor was stronger than that of a single corrosion inhibitor. The addition of the compound inhibitor not only promoted the activation of the anode but also formed a more stable composite protective film on the surface of the anode, which effectively slowed down the self-corrosion and improved the utilization rate of the anode. In NaOH/PAAS/ZnO electrolytes, the dissolution of the Al6061 alloy was mainly controlled by the diffusion of the electric charge in the corrosion products or the zinc salt deposition layer. Meanwhile, for the Al-air battery, the discharge voltage, specific capacity, and specific energy increased by 21.74%, 26.72%, and 54.20%, respectively. In addition, the inhibition mechanism of the composite corrosion inhibitor was also expounded. The excellent discharge performance was due to the addition of the composite corrosion inhibitor, which promoted the charge transfer of the anode reaction, improved the anode's activity, and promoted the uniform corrosion of the anode. This study provides ideas for the application of aluminum–air batteries in the field of new energy. [ABSTRACT FROM AUTHOR]

Nickel oxyhydroxide based energy storage materials have been largely confined by insufficient exposure of active sites which results in low energy efficiency and poor stability. In order to resolve the problems, hierarchical flower array heterostructure NiCoOOH@CoLa‐LDH (denoted as NC@CL) nanosheets are designed with NiCo oxyhydroxide (NiCoOOH, denoted as NC) being tightly covered on CoLa layered double hydroxide (CoLa‐LDH, denoted as CL) nanosheet. This rational design creates more active sites, enlarges the electrode‐electrolyte contact area, improves electron conductivity, and prevents agglomeration during the cycling charge–discharge processes. Density functional theory calculations and differential charges concurrently illustrate that heterostructure formation optimizes the reaction kinetics and promotes electron redistribution. Benefiting from the heterogeneous structure and rich electro‐active sites caused by NC, NC@CL displays outstanding reversible specific capacitance (3228 F g−1 at 1 A g−1). The aqueous rechargeable alkaline Zn battery NC@CL//Zn exhibits a high capacity of 381.1 mA h g−1 at 0.5 A g−1 and cycling durability (98% capacity retention after cycling at 5 A g−1 for 2000 cycles). The excellent electrochemical performances indicate that NC@CL has great application potential as electrode material for aqueous energy storage device. [ABSTRACT FROM AUTHOR]

The main challenges faced by aqueous rechargeable nickel‐zinc batteries are their comparatively low energy density and poor cycling stability, mainly due to the limited capacity and reversibility of existing Ni‐based cathodes. Moreover, the preparation procedures of these cathodes are complex and not easily scalable, which makes them less promising for large‐scale energy storage. Herein, we utilized MXene as a functional additive to effectively improve the electrodeposition preparation of NiCo layered double hydroxides (LDH). Benefiting from the improved interfacial contact between nickel foam (NF) and platting solution and the enhanced ionic conductivity of platting product based on MXene additives, the resulting binder‐free NiCo LDH electrode can achieve ultrahigh areal loading (~65 mg cm−2) with abundant active surface for redox reactions and maintained short transport pathway for ion diffusion and charge transfer. Furthermore, the as‐fabricated alkaline NiCo LDH‐based battery delivers high discharge capacity, up to 20.2 mAh cm−2 (311 mAh g−1), accompanied by remarkable rate performance (9.6 mAh cm−2 or 148 mAh g−1 at 120 mA cm−2). Due to the high structural and chemical stability of MXenes/LDH‐based electrode, excellent cycling life can also be achieved with 88.6 % capacity retention after 10000 cycles. In addition, ultrahigh areal energy density (31.2 mWh cm−2) and gravimetric energy density (465 Wh kg−1) can be simultaneously achieved. This work has inspired the design of advanced cathode materials to develop high‐performance aqueous zinc batteries. [ABSTRACT FROM AUTHOR]

Alkaline all‐iron flow batteries possess intrinsic safety and low cost, demonstrating great potential for large‐scale and long‐duration energy storage. However, their commercial application is hindered by the issue of capacity decay resulting from the decomposition of iron complexes and ligand crossovers. In this paper, an robust anolyte Fe(TEA‐2S) is reported, which is formed by chelating iron ions with the sulfonate‐enriched ligand (TEA‐2S) in alkaline environment. By skillfully designing the ligands, the binding energy of the iron complexes increases and ligand crossovers are suppressed, making the iron complexes highly stable in the charge–discharge cycles. Alkaline all‐iron flow batteries coupling with Fe(TEA‐2S) and the typical iron‐cyanide catholyte perform a minimal capacity decay rate (0.17% per day and 0.0014% per cycle), maintaining an average coulombic efficiency of close to 99.93% over 2000 cycles along with a high energy efficiency of 83.5% at a current density of 80 mA cm−2. In addition, Fe(TEA‐2S) exhibits high solubility of up to 1.85 м (with a theoretical capacity of up to 49.58 Ah L−1), even at low temperatures as extreme as −30 °C. This work demonstrates a promising pathway toward achieving long‐duration and large‐scale energy storage. [ABSTRACT FROM AUTHOR]

The double skeleton interpenetrating network fixed the quaternary ammonium salt, and various internal conduction modes cooperated to promote the transport of hydroxide ions. [Display omitted] The alkaline solid-state electrolytes have received widespread attention for their good safety and electrochemical stability. However, they still suffer from low conductivity and poor mechanical properties. Herein, we report the synthesis of double-network featured hydroxide-conductive membranes fabricated by polyvinyl alcohol (PVA) and chitosan (CS) as the double-skeletons. Then, we implanted quaternary ammonium salt guar hydroxypropyltrimonium chloride (GG) as the OH− conductor for high-performance electrochemical devices. By virtue of the unique stripe-like structure shared from the double skeleton with a high degree of compatibility and stronger hydrogen bond interactions, the polyvinyl alcohol/chitosan-guar hydroxypropyltrimonium chloride (PCG) solid-state electrolytes achieved optimal thermal stability (> 300 °C), mechanical property (∼ 34.15 MPa), dimensional stability (at any bending angle), and high ionic conductivity (13 mS cm−1) and ion mobility number (t ion ∼ 0.90) compared with chitosan-guar hydroxypropyltrimonium chloride (CG) and polyvinyl alcohol-guar hydroxypropyltrimonium chloride (PG) electrolyte membrane. As a proof-of-concept application, the "sandwich"-type zinc-air battery (ZAB) assembled using PCG membrane as the electrolyte realized a high open-circuit voltage (1.39 V) and an excellent power density (128 mW cm−2). Notably, in addition to its long-term cycle life (30 h, 2 mA cm−2) and stable discharge plateau (12 h, 5 mA cm−2), it could even enable a flexible ZAB (F-ZAB) to readily power light-emitting diodes (LED) at any bending angle. These merits afford the PCG membrane a promising electrolyte for improving the performance of solid-state batteries. [ABSTRACT FROM AUTHOR]

The multi‐electron transfer I−/IO3− redox couple is attractive for high energy aqueous batteries. Shifting from an acidic to an alkaline electrolyte significantly enhances the IO3− formation kinetics due to the spontaneous disproportionation reaction, while the alkaline environment also offers more favorable Zn anode compatibility. However, sluggish kinetics during the reduction of IO3− persists in both acidic and alkaline electrolytes, compromising the energy efficiency of this glorious redox couple. Here, we establish the fundamental redox mechanism of the I−/IO3− couple in alkaline electrolytes for the first time and propose that Bi/Bi2O3 acts as a redox mediator (RM) to “catalyze” the reduction of IO3−. This mediation significantly reduces the voltage gap between charge/discharge from 1.6 V to 1 V with improved conversion efficiency and rate capability. By pairing the Zn anode and the Bi/Bi2O3 RM cathode, the full battery with I−/IO3− redox mechanism achieves high areal capacity of 12 mAh cm−2 and stable operation at 5 mAh cm−2 for over 400 cycles. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDHs) are promising electrode materials for alkaline electrochemical energy storage (EES). However, their low capacity, sluggish rate performance, and limited cycle life significantly hinder practical applications. This study unlocks the direct deprotonation reaction pathway for LDH materials through theoretical calculations. Guided by this insight, a novelly hierarchical composite (LDH−TPA) with various dimensions and components is fabricated by introducing terephthalic acid (TPA), serving as a superior cathode material for alkaline EES devices. Experimental results and theoretical investigations reveal the transformation process for metal–organic framework quantum dots (MOF−QDs) and the enhanced mechanism of reaction kinetics in the LDH−TPA electrode. Benefiting from the reduced deprotonation barrier, optimized electronic structure, and fast electrons/ions transport rates, the LDH−TPA1 electrode demonstrates a high specific capacity of 267 mAh g−1 at 1 A g−1 and retains 167 mAh g−1 even at 20 A g−1, along with excellent cycling stability. Furthermore, an alkaline nickel−zinc battery (AZB) with LDH−TPA1 cathode is assembled, achieving a lifespan exceeding 3400 cycles, and a high energy density of 341.3 Wh kg−1 at a power density of 1640.9 W kg−1. This study is expected to provide new insight into the modification of LDHs and the advancement of alkaline energy systems. [ABSTRACT FROM AUTHOR]

Alkaline iron (Fe) batteries are attractive due to the high abundance, low cost, and multiple valent states of Fe but show limited columbic efficiency and storage capacity when forming electrochemically inert Fe3O4 on discharging and parasitic H2 on charging. Herein, sodium silicate is found to promote Fe(OH)2/FeOOH against Fe(OH)2/Fe3O4 conversions. Electrochemical experiments, operando X‐ray characterization, and atomistic simulations reveal that improved Fe(OH)2/FeOOH conversion originates from (i) strong interaction between sodium silicate and iron oxide and (ii) silicate‐induced strengthening of hydrogen‐bond networks in electrolytes that inhibits water transport. Furthermore, the silicate additive suppresses hydrogen evolution by impairing energetics of water dissociation and hydroxyl de‐sorption on iron surfaces. This new silicate‐assisted redox chemistry mitigates H2 and Fe3O4 formation, improving storage capacity (199 mAh g−1 in half‐cells) and coulombic efficiency (94 % after 400 full‐cell cycles), paving a path to realizing green battery systems built from earth‐abundant materials. [ABSTRACT FROM AUTHOR]

Proton activity at the electrified interface is central to the kinetics of proton-coupled electron transfer (PCET) reactions in electrocatalytic oxygen reduction reaction (ORR). Here, we construct an efficient Fe3C water activation site in Fe-N co-doped carbon nanofibers (Fe3C-Fe1/CNT) using an electrospinning-pyrolysis-etching strategy to improve interfacial hydrogen bonding interactions with oxygen intermediates during ORR. In situ Fourier transform infrared spectroscopy and density functional theory studies identified delocalized electrons as key to water activation kinetics. Specifically, the strong electronic perturbation of the Fe–N4 sites by Fe3C disrupts the symmetric electron density distribution, allowing more free electrons to activate the dissociation of interfacial water, thereby promoting hydrogen bond formation. This process ultimately controls the PCET kinetics for enhanced ORR. The Fe3C-Fe1/CNT catalyst demonstrates a half-wave potential of 0.83 V in acidic media and 0.91 V in alkaline media, along with strong performance in H2-O2 fuel cells and Al-air batteries. [ABSTRACT FROM AUTHOR]

Rechargeable alkaline zinc–air batteries (ZAB) hold great promise as a viable, sustainable, and safe alternative energy storage system to the lithium‐ion battery. However, the practical realization of ZABs is limited by their intrinsically low energy trip efficiency, stemming from a large charge and discharge potential gap. This overpotential is attributed to the four‐electron oxygen evolution and reduction reactions and their sluggish kinetics. Here, a new concept based on two‐electron generation and consumption of hydrogen peroxide at the air electrode is introduced. The O2/peroxide chemistry, facilitated by a newly developed Ni‐based bifunctional electrocatalyst, enables fast peroxide generation/consumption, exceptional energy efficiency, high durability, and high capacity. Hence, this new design offers substantial progress toward the commercialization of high energy density metal–air batteries. [ABSTRACT FROM AUTHOR]

Aqueous nickel‐based batteries, particularly nickel‐organic batteries, are promising candidates for large‐scale energy storage applications owing to their environmental friendliness, abundant resources, and intrinsic safety. However, organic anode materials suffer from serious dissolution in electrolytes during discharge/charge processes and ampere‐hour‐scale nickel‐organic batteries are still absent. Here, phenazine (PZ) is screened as the anode and utilizes 10 m KOH as the electrolyte to construct ampere‐hour‐scale PZ/Ni(OH)2 batteries to demonstrate the practicability. In situ, UV–vis and molecular dynamics simulations demonstrate the inhibited dissolution of PZ in high‐concentration of 10 m KOH. The PZ anode can provide a high initial specific capacity of 281.6 mAh g−1 at 0.5 C with a Coulombic efficiency of 98.6% and ultralong cycle life with a capacity retention of 74.3% after 14 000 cycles at 30 C. Moreover, the fabricated pouch‐type PZ/Ni(OH)2 battery with a high PZ mass‐loading of 48 mg cm−2 delivers a capacity of 1.23 Ah and achieves a high energy density of 50 Wh kg−1 (based on the total mass of the cell). The abundant resources, excellent stability, and cost‐effectiveness of phenazine endow nickel‐organic batteries with promising potential for large‐scale energy storage applications. [ABSTRACT FROM AUTHOR]

The capacity and cycling performance of cathodes are key factors in aqueous zinc batteries (AZBs). The search for cathode materials with long cycle lives and high specific capacities is of paramount importance. In this study, a bimetallic telluride with a hollow polyhedral structure was synthesized using a hydrothermal method followed by vapor deposition. This composite exhibits high conductivity, facilitates rapid diffusion of electrolyte ions into the interior, and accelerates redox reactions, thereby enhancing electrochemical performance. The CoTe2 -NiTe2 electrode demonstrates an impressive specific capacity of 188.8 mAh/g at 1 A/g, highlighting its efficiency in storing a significant amount of charge per unit mass during electrochemical reactions. The assembled CoTe2 -NiTe2//Zn battery shows favorable capacity retention (76.4%) after 10000 cycles. The energy density is remarkably high, reaching 290.3 Wh/kg, while maintaining a power density of 1.75 kW/kg. This bimetallic telluride strategy holds great promise as an alternative cathode for AZBs. [ABSTRACT FROM AUTHOR]

A new atomic-level strategy is introduced to finely optimize the OH− adsorption/desorption capability of β-Ni(OH) 2 through tailoring the 3d-orbital occupancy of Ni center via Co and Cu co-doping. [Display omitted] • The 3d-orbital electron occupancy of Ni species in β-Ni(OH) 2 can be optimized. • The interaction mechanism between OH− and Ni(OH) 2 is fully studied. • Co-Cu-Ni(OH) 2 electrode delivers a good capacity of 170.8 mAh g−1 and 2.3 mAh cm−2. The capacity and cycling stability of β-Ni(OH) 2 -based cathodes in aqueous alkaline Ni-Zn batteries are still unsatisfactory due to their undesirable OH− adsorption/desorption dynamics during the electrochemical redox process. To settle this issue, we introduce a new atomic-level strategy to finely modulate the OH− adsorption/desorption of β-Ni(OH) 2 through tailoring the 3d-orbital occupancy of Ni center by Co/Cu co-doping (denoted as Co-Cu-Ni(OH) 2). Both experimental outcomes and density functional theory calculations validate that the co-doping of Co and Cu endows the Ni species in Co-Cu-Ni(OH) 2 with appropriate proportion of the unoccupied 3d-orbital, leading to optimized adsorption/desorption strength of OH−. As anticipated, the Co-Cu-Ni(OH) 2 electrode demonstrates superior performance, achieving an areal capacity of 0.83 mAh cm−2 and a gravimetric capacity of 164.3 mAh g−1 at ∼50 mA cm−2 (10 A g−1). Furthermore, it sustains an impressive capacity of 170.8 mAh g−1 (2.3 mAh cm−2) at a high mass loading of 13.5 mg cm−2, alongside a long-term cycling performance over 1000 cycles. The assembled Co-Cu-Ni(OH) 2 //Zn cell is able to provide a peak energy density of 0.98 mWh cm−2 and excellent durability. This work highlights the potential of an orbital engineering strategy in the development of next-generation high-capacity and durable energy storage materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dodecahedral Cu Fe/N C was synthesized by interfacial assembly and pyrolysis. • Introduction of Cu enhances both electrical conductivity and ORR catalytic activity. • The electronic structure of Fe N x is modulated by synergistic effect of Fe and Cu. • The ZAB with Cu Fe/N C catalyst can stably cycle for 600 h with a low polarization. Oxygen reduction reaction (ORR) serves as the foundation for various electrochemical energy storage devices. Fe/N C catalysts are expected to replace commercial Pt/C as oxygen electrode catalysts based on the structural tunability at the atomic level, abundant iron ore reserves and excellent activity. Nevertheless, the lack of durability and low active site density impede its advancement. In this work, a durable catalyst, Cu Fe/N C, for ORR was prepared by modulating the interfacial composition and electronic structure. The introduction of Cu nanoclusters partially eliminates the Fenton effect from Fe and optimizes the electron structure of Fe N x , thereby effectively enhancing the long-term durability and activity. The prepared Cu Fe/N C exhibits a half-wave potential (E 1/2) of 0.90 V and superior stability with a decrease in E 1/2 of only 20 mV after 10,000 cycles. The assembled alkaline Zinc-Air batteries (ZABs) with Cu Fe/N C exhibit an open-circuit potential of 1.458 V. At a current density of 5 mA cm−2, the batteries are capable of operation for 600 h with a stable polarization. This Cu Fe/N C may promote the practical application of novel and renewable electrochemical energy storage devices. [ABSTRACT FROM AUTHOR]

In this study, zinc, which is an important industrial metal and a major component of alkaline batteries, was extracted from spent alkaline batteries using polyurethane foam (PUF) impregnated with the solvent Cyanex 272. The impregnation of PUF with Cyanex 272 was confirmed using Fourier transform infrared spectroscopy. Relevant experimental factors (such as pH, solvent concentration, absorbent dosage, temperature, and flow rate) affecting the extraction of zinc were investigated. Fourier transform infrared spectroscopy showed that PUF can be easily impregnated with Cyanex 272. The optimal conditions for this Zn recovery are: pH 4; extractant concentration = 0.4 M; adsorbent dosage = 5 g; temperature ≈ 338 K; and extraction time = 60 min. The Avrami fractional-order kinetic model was the best model for describing the kinetic data, while the Bohart–Adams model was the best model for the data of the columnar study. The results show that the solvent impregnation method is an effective technique of zinc extraction from spent alkaline batteries; ≈95.7% of Zn was recovered from the sample after elution with 6 M HCl. Hence, Zn can be effectively recovered from solution (spent batteries) using PUF impregnated with Cyanex 272. [ABSTRACT FROM AUTHOR]

Transition metal oxides (TMOs) are highly dense in energy and considered as promising anode materials for a new generation of alkaline ion batteries. However, their electrode structure is disrupted due to significant volume changes during charging and discharging, resulting in the short cycle life of batteries. In this paper, the hierarchical Ni3V2O8@N‐doped carbon (Ni3V2O8@NC) hollow double‐shell microspheres were prepared and used as electrode materials for lithium‐ion batteries (LIBs). The utilization efficiency and ion transfer rate of Ni3V2O8 were improved by the hollow microsphere structure formed through nanoparticle self‐assembly. Furthermore, the uniform N‐doped carbon layer not only enhanced the structural stability of Ni3V2O8, but also improved the overall electrical conductivity of the composite. The Ni3V2O8@NC electrode has an initial discharge capacity of up to 1167.3 mAh g−1 at a current density of 0.3 A g−1, a reversible capacity of up to 726.5 mAh g−1 after 200 cycles, and still has a capacity of 567.6 mAh g−1 after 500 cycles at a current density of 1 A g−1, indicating that the material has good cycle stability and high‐rate capability. This work presents new findings on the design and fabrication of complex porous double‐shell nanostructures. [ABSTRACT FROM AUTHOR]

Herein, a disubstitution strategy of metal ions and organic ligands is employed to synthesize metal–organic framework (MOF) nanosheets with a three-dimensional (3D) porous structure and a highly active metal–sulfur (M–S, M = Co and Ni) region. The obtained MOFs//Zn batteries exhibit excellent electrochemical properties and the electrochemical reaction mechanism was elucidated through a series of ex situ characterizations. [ABSTRACT FROM AUTHOR]

Crown ethers (CEs), known for their exceptional host–guest complexation, offer potential as linkers in covalent organic frameworks (COFs) for enhanced performance in catalysis and host–guest binding. However, their highly flexible conformation and low symmetry limit the diversity of CE‐derived COFs. Here, we introduce a novel C3‐symmetrical azacrown ether (ACE) building block, tris(pyrido)[18]crown‐6 (TPy18C6), for COF fabrication (ACE‐COF‐1 and ACE‐COF‐2) via reticular synthesis. This approach enables precise integration of CEs into COFs, enhancing Ni2+ ion immobilization while maintaining crystallinity. The resulting Ni2+‐doped COFs (Ni@ACE‐COF‐1 and Ni@ACE‐COF‐2) exhibit high discharge capacity (up to 1.27 mAh ⋅ cm−2 at 8 mA ⋅ cm−2) and exceptional cycling stability (>1000 cycles) as cathode materials in aqueous alkaline nickel‐zinc batteries. This study serves as an exemplar of the seamless integration of macrocyclic chemistry and reticular chemistry, laying the groundwork for extending the macrocyclic‐synthon driven strategy to a diverse array of COF building blocks, ultimately yielding advanced materials tailored for specific applications. [ABSTRACT FROM AUTHOR]

Introduction Blast overpressure and accelerative impact can produce concussive-like symptoms in service members serving both garrison and deployed environments. In an effort to measure, document, and improve the response to these overpressure and impact events, the U.S. Army Medical Material Development Activity is evaluating body-worn sensors for use by the Joint Conventional Force. In support, the WRAIR completed a qualitative end-user evaluation with service members from high-risk mission occupational specialties to determine the potential needs, benefits, and challenges associated with adopting body-worn sensors into their job duties. Materials and Methods WRAIR staff led hour-long semi-structured focus groups with 156 Army, Navy, and Marine Corps participants, primarily representing infantry, combat engineer, explosive ordnance disposal, artillery, mortar, and armor job specialties. Topics included their sensor needs, concepts of operations, and recommended design features for implementing sensors into the force. Dialogue from each focus group was audio recorded and resulting transcripts were coded for thematic qualitative analysis using NVivo software. Results Users recommended a single, unobtrusive, rugged, multi-directional sensor that could be securely mounted to the helmet and powered by a battery type (such as rechargeable lithium or disposable alkaline batteries) that was best suited for their garrison and field/deployed environments. The sensors should accurately measure low-level (∼1.0 pounds per square inch) blasts and maintain a record of cumulative exposures for each service member. Discussions supported the need for immediate, actionable feedback from the sensor with the option to view detailed blast or impact data on a computer. There were, however, divergent opinions on security issues regarding wireless versus wired data transfer methods. Participants also expressed a need for the exposure data to integrate with their medical records and were also willing to have their data shared with leadership, although opinions differed on the level of echelon and if the data should be identifiable. Regarding accountability, users did not want to be held fiscally liable for the sensors and recommended having the unit be responsible for maintenance and distribution. Concerns about being held fiscally liable, being overly burdened, and having one's career negatively impacted were listed as factors that could decrease usage. Finally, participants highlighted the importance of understanding the purpose and function of the sensors and supported a corresponding training module. Conclusions Participating service members were generally willing to adopt body-worn sensors into their garrison and deployed activities. To maximize adoption of the devices, they should be convenient to use and should not interfere with service members' job tasks. Providing a clear understanding of the benefits (such as incorporating exposure data into medical records) and the function of sensors will be critical for encouraging buy-in among users and leaders. Incorporating end-user requirements and considering the benefits and challenges highlighted by end users are important for the design and implementation of body-worn sensors to mitigate the risks of blast overpressure and accelerative impact on service members' health. [ABSTRACT FROM AUTHOR]

In this work, pyroelectric materials can spontaneously polarize and generate an internal electric field when heated, and the photocatalyst will have band bending under the action of the internal electric field, which promotes the separation of photogenerated carriers. When HCN@PVTC@CdS is used as a photocathode pole, due to the presence of internal electric field generated by pyroelectric effect, the photocatalyst attached to the pyroelectric material will be affected, and its energy band will bend, which is conducive to the separation of photogenerated charge carriers, accelerating the reaction kinetics of the battery. [Display omitted] Zinc–air battery as one of the new generations of battery system, its theoretical specific energy is as high as 1086 Wh kg−1, specific capacity up to 820 mAh/g, and zinc has the advantages of environmental friendliness, resource abundance, low cost and good safety, so it has attracted much attention. However, due to its slow reaction kinetic process, zinc–air battery will produce a large charging overpotential usually up to 2 V, it is far beyond the theoretical voltage of 1.65 V, so reducing the overpotential of zinc–air batteries is extremely necessary, and the most common way to solve this problem is to use excellent catalyst cathode to improve the oxygen reduction and oxygen evolution kinetics of zinc–air batteries. So we developed a new photothermal assisted zinc–air battery system with Hollow carbon nanosphere@poly (vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)@CdS (HCN@PVTC@CdS) photocathode, the pyroelectric and photocatalysis effect can effectively promote the reaction kinetics and reduce the reaction overpotential. With the pyroelectric and photocatalysis synergistic effect, the zinc–air has displayed a high discharge potential of 1.33 V and a low charging potential of 1.5 V with good cycle stability. This multi-assist technology with built-in electric and light fields paves the way for the development of high-performance zinc–air batteries and other energy storage systems. [ABSTRACT FROM AUTHOR]

Rechargeable neutral aqueous zinc−air batteries (ZABs) are a promising type of energy storage device with longer operating life and less corrosiveness compared with conventional alkaline ZABs. However, the neutral ZABs normally possess poor oxygen evolution reactions (OERs) and oxygen reduction reactions performance, resulting in a large charge–discharge voltage gap and low round‐trip efficiency. Herein, we demonstrate a sunlight‐assisted strategy for achieving an ultralow voltage gap of 0.05 V in neutral ZABs by using the FeOOH‐decorated BiVO4 (Fe‐BiVO4) as an oxygen catalyst. Under sunlight, the electrons move from the valence band (VB) of Fe‐BiVO4 to the conduction band producing holes in VB to promote the OER process and hence reduce the overpotential. Meanwhile, the photopotential generated by the Fe‐BiVO4 compensates a part of the charging potential of neutral ZABs. Accordingly, the energy loss of the battery could be compensated via solar energy, leading to a record‐low gap of 0.05 V between the charge and discharge voltage with a high round‐trip efficiency of 94%. This work offers a simple but efficient pathway for solar‐energy utilization in storage devices, further guiding the design of high energy efficiency of neutral aqueous ZABs. [ABSTRACT FROM AUTHOR]

The integration of atom clusters and single atoms into a unified system represents a desirable approach for attaining enhanced catalytic performance. Nonetheless, the controllable synthesis of a single‐atom and nanocluster integrated system (SA‐NC) faces considerable challenges, and the mechanisms underlying the catalytic activity remain poorly understood. In this research, a cobalt‐based catalyst containing both coordinatively unsaturated single‐atom (CoN3) and small nanoclusters (Co@SA‐NC) is synthesized. The Co@SA‐NC not only facilitates charge and mass transfer due to the interconnected long‐range micromorphology, thus endowing efficient oxygen electrocatalytic reaction (ORR/OER), but also undergoes surface reconfiguration upon OH adsorption at high potentials in alkaline ORR/OER conditions. More appealingly, this OH‐involved reconfigured adaptive structure promotes optimization of energy barriers owing to the dynamic regulation from the bridged OH between Co single‐atom and cluster in the whole reaction process. Specific to the application metrics, a zinc–air battery assembled using the Co@SA‐NC catalyst exhibit targeted power density enhancement with 270 mW cm−2 in an alkaline medium. This work offers an effective insight into the study of SA‐NC catalytic reaction pathways for efficient ORR/OER catalysis. [ABSTRACT FROM AUTHOR]

The strategic regulation of the electronic properties and coordination environment of single‐atom sites through the integration of metal nanoclusters emerges as a promising route to enhance the oxygen reduction reaction (ORR) performance of Fe–N–C materials. Here, a catalyst (FeIn–NC) is successfully developed in which Fe–N–C materials encapsulate Fe–In alloy nanoclusters, and it shows excellent ORR activity and durability under alkaline conditions, with a high half‐wave potential of 0.924 V (vs RHE) and a zinc–air battery power density of 202.1 mW cm−2, superior to commercial Pt/C catalysts. Theoretical calculations unravel that the synergistic interaction between the Fe–In alloy and the FeN4 single‐atom site modifies the electronic structure and charge distribution at the FeN4 site, thereby enhancing the electrocatalytic activity and durability of the ORR. Potential‐dependent microkinetic modeling (MKM) further discloses the ORR mechanisms on the identified FeN4 sites. This work provides a viable strategy for the ORR improvement of Fe–N–C materials via p‐block metal‐based alloy nanoclusters. [ABSTRACT FROM AUTHOR]

The Co-WS 2 heterostructure, loaded on nanofibers with faster electron transport rates, was designed and developed using a top-down approach to achieve high HER performance in alkaline electrolytes. Driven by the inherent electric field induced by the work function difference between Co and WS 2 , efficient electron transfer at the interface optimizes the adsorption energy of reaction intermediates and boosts catalytic activity. [Display omitted] Designing and developing cost-effective, high-performance catalysts for hydrogen evolution reaction (HER) is crucial for advancing hydrogen production technology. Tungsten-based sulfides (WS x) exhibit great potential as efficient HER catalysts, however, the activity is limited by the larger energy required for water dissociation under alkaline conditions. Herein, we adopt a top-down strategy to construct heterostructure Co-WS 2 nanofiber catalysts. The experimental results and theoretical simulations unveil that the work functions-induced built-in electric field at the interface of Co-WS 2 catalysts facilitates the electron transfer from Co to WS 2 , significantly reducing water dissociation energy and optimizing the Gibbs free energy of the entire reaction step for HER. Besides, the self-supported catalysts of Co-WS 2 nanoparticles confining 1D nanofibers exhibit an increased number of active sites. As expected, the heterostructure Co-WS 2 catalysts exhibit remarkable HER activity with an overpotential of 113 mV to reach 10 mA cm−2 and stability with 30 h catalyzing at 23 mA cm−2. This work can provide an avenue for designing highly efficient catalysts applicable to the field of energy storage and conversion. [ABSTRACT FROM AUTHOR]

Aqueous Organic Redox Flow Batteries are a family of promising energy storage systems. However, they face various challenges related to their lifetime, such as the Faradaic imbalance due to the occurrence of parasitic reaction leading to the fading of its energy storage capacity. Herein, automatization of a rebalancing system to reverse the detrimental effects of Faradaic imbalance due to the unavoidable presence of small quantities of oxygen in the negative reservoir or hydrogen evolution reaction is developed and implemented in an alkaline flow battery. A membrane‐free rebalancing cell is proposed to promote the oxygen evolution reaction and reverse the accumulated charge in the catholyte showing a 100 % coulombic efficiency. The programmable logic controller monitors the open circuit voltage to calculate the charge stored in each charge/discharge step and closes a circuit so a fixed voltage is applied to the rebalancing cell when the battery needs to be rebalanced. The system is tested using an alkaline flow battery consisting of ferrocyanide and 2,6‐dihydroxyanthraquinone, improving the energy capacity retention from 0.27 % cycle‐1 and 0.47 % h‐1 without rebalancing system to 100 % retention after >850 cycles and >24 days (without Ar‐filled glovebox), demonstrating the feasibility of this proposed system to address the Faradaic imbalance. [ABSTRACT FROM AUTHOR]

In this work, we study and compare the electrochemical performance of Li-ion battery (LIB) with and without a BiFe0.95Cu0.05O3 thin film coating. The BiFe0.95Cu0.05O3 thin film is deposited on both LiNi0.5Mn0.3Co0.2O2 (NMC532) cathode and graphite anode electrodes using radio frequency magnetron sputtering. By using galvanostatic charge–discharge measurements, we observe that, in contrast to LIB without BiFe0.95Cu0.05O3 coating, the charging curve of LIB with BiFe0.95Cu0.05O3 coating exhibits a counterintuitive negative slope of the negative electron compressibility (NEC) with a rate of NEC equal to −16.36 × 10−11 meV per electron per cm2. Importantly, we find that the NEC effect has the potential to enhance the energy density in LIB with BiFe0.95Cu0.05O3 coating. The energy density of the first discharge cycle is dramatically increased from 190 Wh/kg for pristine LIB to 255 Wh/kg for LIB coated with the BiFe0.95Cu0.05O3 film. We suggest the origin of this with the change in Mott gap and a concept to apply the NEC effect for enhancing energy density LIB batteries. [ABSTRACT FROM AUTHOR]

An efficient 3D bifunctional nanofiber electrocatalyst with synergistic multiple active sites for high-performance aqueous/solid ZABs was developed by electrospinning and MOF/COF in-situ growth strategy. [Display omitted] Covalent organic frameworks (COFs) and metal–organic frameworks (MOFs) have attracted growing attention in electrochemical energy storage and conversion systems (e.g., Zn-air batteries, ZABs) owing to their structural tunability, ordered porosity and high specific surface area. In this work, for the first time, the three-dimensional (3D) highly open catalyst (CNFs/CoZn-MOF@COF) possessing hierarchical porous structure and high-density active sites of uniform cobalt (Co) nanoparticles and metal-N x (M-N x , M = Co and Zn) is demonstrated, which is fabricated using electrospinning technique in combination with MOF/COF hybridization strategy and direct pyrolysis. Benefiting from the well-designed branch-leaf nanostructures, plentiful and uniform active sites on the MOF/COF-derived carbon frameworks, as well as the synergistic effect of multiple active sites, CNFs/CoZn-MOF@COF catalyst achieves superior electrocatalytic activity and stability towards both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with a small potential gap (ΔE = 0.75 V). In situ Raman spectroscopy and X-ray photoelectron spectroscopy results indicate that the CoOOH intermediates are the main active species during OER/ORR. Significantly, both aqueous and all-solid-state rechargeable ZABs assembled with CNFs/CoZn-MOF@COF as the air cathode show high open-circuit potential, outstanding peak power density, large capacity and long cycle life. More impressively, the obtained all-solid-state ZAB also displays superb mechanical flexibility and device stability under different, showcasing great application deformations potential in portable and wearable electronics. This work provides a new insight into the design and exploitation of bifunctional catalysts from MOF/COF hybrid materials for energy storage and conversion devices. [ABSTRACT FROM AUTHOR]

[Display omitted] VO 2 (B) is recognized as a promising cathode material for aqueous zinc metal batteries (AZMBs) owing to its remarkable specific capacity and its unique, expansive tunnel structure, which facilitates the reversible insertion and extraction of Zn2+. Nonetheless, challenges such as the inherent instability of the VO 2 structure, poor ion/electron transport and a limited capacity due to the low redox potential of the V3+/V4+ couple have hindered its wider application. In this study, we present a strategy to replace vanadium ions by doping Al3+ in VO 2. This approach activates the multi-electron reaction (V4+/V5+), to increase the specific capacity and improve the structural stability by forming robust V5+ O and Al3+ O bonds. It also induces a local electric field by altering the local electron arrangement, which significantly accelerates the ion/electron transport process. As a result, Al-doped VO 2 exhibits superior specific capacity, improved cycling stability, and accelerated electronic transport kinetics compared to undoped VO 2. The beneficial effects of heterogeneous atomic doping observed here may provide valuable insights into the improvement electrode materials in metal-ion battery systems other than those based on Zn. [ABSTRACT FROM AUTHOR]

Alkaline zinc‐ferricyanide flow batteries are efficiency and economical as energy storage solutions. However, they suffer from low energy density and short calendar life. The strongly alkaline conditions (3 mol L−1 OH−) reduce the solubility of ferri/ferro‐cyanide (normally only 0.4 mol L−1 at 25 °C) and induce the formation of zinc dendrites at the anode. Here, we report a new zinc‐ferricyanide flow battery based on a mild alkalescent (pH 12) electrolyte. Using a chelating agent to rearrange ferri/ferro‐cyanide ion‐solvent interactions and improve salt dissociation, we increased the solubility of ferri/ferro‐cyanide to 1.7 mol L−1 and prevented zinc dendrites. Our battery has an energy density of ~74 Wh L−1catholyte at 60 °C and remains stable for 1800 cycles (1800 hours) at 0 °C and for >1400 cycles (2300 hours) at 25 °C. An alkalescent zinc‐ferricyanide cell stack built using this alkalescent electrolyte stably delivers 608 W of power for ~40 days. [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion batteries (AZiBs) have emerged as a promising alternative to lithium-ion batteries as energy storage systems from renewable sources. Manganese hexacyanoferrate (MnHCF) is a Prussian Blue analogue that exhibits the ability to insert divalent ions such as Zn2+. However, in an aqueous environment, MnHCF presents weak structural stability and suffers from manganese dissolution. In this work, zinc doping is explored as a strategy to provide the structure with higher stability. Thus, through a simple and easy-to-implement approach, it has been possible to improve the stability and capacity retention of the cathode, although at the expense of reducing the specific capacity of the system. By correctly balancing the amount of zinc introduced into the MnHCF it is possible to reach a compromise in which the loss of capacity is not critical, while better cycling stability is obtained. [ABSTRACT FROM AUTHOR]

A series of bimetallic cobalt-based MOF nanosheets were successfully prepared through simple hydrothermal progress, which shows superior performance for aqueous rechargeable cobalt-zinc batteries. [Display omitted] Aqueous rechargeable Zn-based batteries (ARZBs) have attracted increasing attention as favorable candidates for energy storage systems due to their high security, environmental friendliness, and abundance of electrode materials. At present, the most widely reported materials used in cobalt-zinc (Co-Zn) batteries are cobalt-based oxides and their derivatives, however, they still exhibit low actual capacities and unsatisfactory cycle lives. Metal-organic frameworks (MOFs), as a new class of porous materials with high specific surface area and adjustable pore size, have attracted considerable attention in the field of energy storage. Currently, pristine MOFs have currently few applications in Co-Zn batteries, and their performance is not ideal. Herein, we report a series of two-dimensional (2D) bimetallic CoM-MOF (M = Ni, Mn, Mg and Cu) nanosheets based on trimesic acid (H 3 BTC) ligand as cathodes for alkaline Co-Zn batteries via a simple one-pot hydrothermal synthesis. Among the synthesized MOFs, the CoNi-MOF nanosheets have the best performance, exhibiting a high reversible capacity of 344 mA h g−1 and demonstrating a good cycling life with 90 % capacity retention at 20 A g−1 after 1500 cycles. The energy storage mechanism is studied through a series of ex-situ characterizations. This study is of great importance in advancing the application of 2D pristine MOFs for high-performance Co-Zn batteries. [ABSTRACT FROM AUTHOR]

While alkaline Zn batteries, like traditional rechargeable aqueous batteries, boast an advantage in terms of energy density, their progress has been hampered by concerns related to the anode. These concerns include issues like Zn dendrites, self‐corrosion, passivation, shape change, and the hydrogen evolution reaction (HER). To tackle these challenges, we have introduced a nanostructuring approach for the anode, employing carbon‐coated ZnO nanoparticles (ZnO@C) as the active material. In this study, we synthesized ZnO@C nanoparticles in an environmentally sustainable and scalable manner to address passivation and dissolution issues jointly. Nanoscale ZnO particles effectively prevent passivation, while carbon shell slows down the dissolution of zincate. The Zn anode exhibits a significant performance boost when compared to Zn foil and bare ZnO nanoparticles, even when subjected to demanding conditions (without the use of ZnO‐saturated electrolyte). This rechargeable Zn anode marks a significant step toward the realization of practical, high‐energy rechargeable aqueous batteries, such as Zn‐air batteries. [ABSTRACT FROM AUTHOR]