Aqueous zinc-ion batteries (AZIBs) have important application prospects in the field of high-temperature energy storage. However, traditional aqueous electrolytes have high ionic conductivity, but they are challenged by hydrogen evolution reactions and imbalanced of zinc-ion transference number. To address this issue, we used acrylamide guar gum as the skeleton and introduced potassium 3-sulfonate propyl methacrylate (SPMAK), through the Hofmeister effect. On the one hand, sulfonic acid groups form strong coordination with zinc-ion, reconstructing the solvation sheath of hydrated zinc-ion and replacing some active water molecules, significantly reducing the desolvation energy barrier, while reconstructing the hydrogen bond network, inhibiting proton conduction and hydrogen evolution side reactions. On the other hand, SPMAK can construct highly ordered sulfonic end nanochannels on the electrode surface, forming zinc-ion selective transport channels, increasing the zinc-ion transference number to around 0.68, and achieving uniform distribution of ion flux. This further solves the problems of low and uneven distribution of hydrogen evolution reaction and zinc-ion transport efficiency at high temperatures. At 60 ℃, the coulomb efficiency of AKG-Z gel electrolyte reached 99.02% after 370 cycles. Under the conditions of 60 ℃ and 1 A g−1, the capacity retention rate of Zn || AKG-Z || MnO2 batteries remained as high as 95.1% after 1500 cycles, demonstrating excellent high-temperature long cycle stability.

Aqueous zinc ion batteries (AZIBs) show promise for future energy storage due to affordability and safety. However, industrial application is hindered by parasitic reactions and zinc dendrites. We address this by adding 1-ethyl-3-methylimidazolium dicyandiamide ([Emim][DCA], or ED) to the electrolyte, suppressing water reduction and Zn dendrite growth. The strong coordination between zinc and nitrogen-containing ligands leads to DCA-anion adsorption on the zinc anode, forming a dense Zn(DCA)2 layer. This layer aids zinc ion desolvation and isolates water molecules, enabling water-free deposition and facilitating reversible plating/stripping. Additionally, in the water-poor double electric layer, zinc cations introduce triflate anions to the zinc electrode surface, forming an in-situ fluorine-based SEI layer. This layer separates zinc electrodes from water, inhibiting corrosion, and hydrogen evolution. With ED additives, Zn||Zn symmetric cells maintain a cycle life of over 2500 h at 0.5 mA cm-2 and 0.5 mAh cm-2. Zn||Ti asymmetric cells achieve 99.4 % Coulombic efficiency. The Zn||PANI full cell lasts for 1000 cycles at 4 A g-1 without a significant decrease in specific capacity.

Hydrogen oxidation reaction in alkaline media is critical for alkaline fuel cells and electrochemical ammonia compressors. The slow hydrogen oxidation reaction in alkaline electrolytes requires large amounts of scarce and expensive platinum catalysts. While transition metal decoration can enhance Pt catalysts’ activity, it often reduces the electrochemical active surface area, limiting the improvement in Pt mass activity. Here, we enhance Pt catalysts’ activity without losing surface-active sites by using a Pd-Ru pair. Utilizing a mildly catalytic thermal pyrolysis approach, Pd-Ru pairs are decorated on Pt, confirmed by extended X-ray absorption fine structure and high-angle annular dark-field scanning transmission electron microscopy. Density functional theory and ab-initio molecular dynamics simulations indicate preferred Pd and Ru dopant adsorption. The Pd-Ru decorated Pt catalyst exhibits a mass-based exchange current density of 1557 ± 85 A g−1metal for hydrogen oxidation reaction, demonstrating superior performance in an ammonia compressor. Hydrogen oxidation in alkaline media is vital for fuel cells and ammonia compressors but typically requires costly platinum catalysts. Here the authors report a Pd-Ru pair decorated on Pt to enhance the mass activity of noble-metal for hydrogen oxidation reactions.

Metal-water primary batteries hold promise for distributed hydrogen production but suffer from limited renewability of metal electrodes in aqueous electrolytes. Here, we introduce a novel concept of a rechargeable zinc-water battery featuring a reversible zinc anode paired with a bifunctional water electrolysis electrode, realized in a specially designed aqueous electrolyte-a mild zinc triflate aqueous electrolyte with the addition of ethylenediaminetetraacetic acid disodium (EDTANa2). The system enables high-purity hydrogen production during discharge and high-purity oxygen production during charge in a membrane-free setup. In the zinc-water battery, EDTANa2 enhances the water-splitting electrode's performance by replacing hydrophobic OTF- anions, ensuring optimal water activity. Additionally, EDTANa2 enhances Zn electrode reversibility by chelating Zn2+, preventing solvated water decomposition during zinc deposition. This integrated battery continuously undergoes charge-discharge cycles for over 55hours at a current density of 6mAcm-2. Moreover, it achieves a high hydrogen evolution rate of 12.5mLcm-2 h-1, enabling cost-effective, high-purity hydrogen production without expensive membranes. These findings open new avenues for sustainable hydrogen generation and energy storage in nano energy systems.

The technique of graph/network embedding can help computer to efficiently analyze and process the complex graph data via vector operations. Graph Neural Network, which aggre-gates the topological information of the neighbourhoods of each node in a graph to imple-ment graph/network embedding, has attracted wide attention. With the explosive growth of information, large amounts of data need to be expressed in the form of hypergraphs. As a result, the hypergraph neural networks arise at the historic moment. However, most cur-rent work is based on static hypergraph structure, making it hard to effectively transmit information. To address this problem, Dynamic Hypergraph Neural Networks based on Key Hyperedges (DHKH) model is proposed in this paper. Considering that the graph structure data in the real world is not uniformly distributed both semantically and struc-turally, we define the key hyperedge as the subgraph composed of a small number of key nodes and related edges in a graph. The key hyperedge can capture the key high-order structure information, which is able to enhance global topology expression. With the sup-porting of hyperedge and key hyperedge, DHKH can aggregate the high-order information and key information. In our experiments, DHKH shows good performance on multiple datasets, especially on the SZ dataset and LOS dataset which have inherently some key structures.(c) 2022 Elsevier Inc. All rights reserved.

Metallic zinc is an ideal anode due to its high theoretical capacity (820 mAh g −1 ), low redox potential (−0.762 V versus the standard hydrogen electrode), high abundance and low toxicity. When used in aqueous electrolyte, it also brings intrinsic safety, but suffers from severe irreversibility. This is best exemplified by low coulombic efficiency, dendrite growth and water consumption. This is thought to be due to severe hydrogen evolution during zinc plating and stripping, hitherto making the in-situ formation of a solid–electrolyte interphase (SEI) impossible. Here, we report an aqueous zinc battery in which a dilute and acidic aqueous electrolyte with an alkylammonium salt additive assists the formation of a robust, Zn 2+ -conducting and waterproof SEI. The presence of this SEI enables excellent performance: dendrite-free zinc plating/stripping at 99.9% coulombic efficiency in a Ti||Zn asymmetric cell for 1,000 cycles; steady charge–discharge in a Zn||Zn symmetric cell for 6,000 cycles (6,000 h); and high energy densities (136 Wh kg −1 in a Zn||VOPO 4 full battery with 88.7% retention for >6,000 cycles, 325 Wh kg −1 in a Zn||O 2 full battery for >300 cycles and 218 Wh kg −1 in a Zn||MnO 2 full battery with 88.5% retention for 1,000 cycles) using limited zinc. The SEI-forming electrolyte also allows the reversible operation of an anode-free pouch cell of Ti||Zn x VOPO 4 at 100% depth of discharge for 100 cycles, thus establishing aqueous zinc batteries as viable cell systems for practical applications.

Composite polymer electrolytes (CPEs) for solid-state Li-metal batteries (SSLBs) still suffer from gradually increased interface resistance and unconstrained Li-dendrite growth. Herein, we addressed the challenges by designing a LiF-rich inorganic solid-electrolyte interphase (SEI) through introducing a fluoride-salt-concentrated interlayer on CPE film. The rigid but flexible CPE helps accommodate the volume change of electrodes, while the polymeric highly concentrated electrolyte (PHCE) surface-layer regulates Li-ion flux due to the formation of a stable LiF-rich SEI via anion reduction The designed CPE-PHCE presents enhanced ionic conductivity and high oxidation stability of >5.0 V (versus Liar). Furthermore, it dramatically reduces the interfacial resistance and achieves a high critical current density of 4.5 mA cm(-2) The SSLBs, fabricated with thin CPE-PHCE membranes (<100 mu m) and Co-free LiNiO2 cathodes, exhibit exceptional electrochemical performance and long cycling stability. This approach of SEI design can also be applied to other types of batteries.

Aqueous Zn batteries promise high energy density but suffer from Zn dendritic growth and poor low-temperature performance. Here, we overcome both challenges by using an eutectic 7.6 m ZnCl 2 aqueous electrolyte with 0.05 m SnCl 2 additive, which in situ forms a zincophilic/zincophobic Sn/Zn 5 (OH) 8 Cl 2 ⋅H 2 O bilayer interphase and enables low temperature operation. Zincophilic Sn decreases Zn plating/stripping overpotential and promotes uniform Zn plating, while zincophobic Zn 5 (OH) 8 Cl 2 ⋅H 2 O top-layer suppresses Zn dendrite growth. The eutectic electrolyte has a high ionic conductivity of ≈0.8 mS cm −1 even at −70 °C due to the distortion of hydrogen bond network by solvated Zn 2+ and Cl − . The eutectic electrolyte enables Zn∥Ti half-cell a high Coulombic efficiency (CE) of >99.7 % for 200 cycles and Zn∥Zn cell steady charge/discharge for 500 h with a low overpotential of 8 mV at 3 mA cm −2 . Practically, Zn∥VOPO 4 batteries maintain >95 % capacity with a CE of >99.9 % for 200 cycles at −50 °C, and retain ≈30 % capacity at −70 °C of that at 20 °C.

The technique of graph/network embedding in artificial intelligence, which embeds graph data into a low-dimensional vector space in the form of machine learning, can help computer to efficiently process and analyze the complex graph data by using the vector operations. Graph Neural Network (GNN) and neural network, an end-to-end graph embedding technique based on Graph Signal Processing (GSP), which aggregates the topological information of the neighborhoods of each node in a graph, has attracted wide attention. However, most of the existing GNN models are limited to local structure information, and the location differences of nodes in the global topology are not sufficiently considered. This leads to that many nodes with the similar local topology are very difficult to distinguish. To address this problem, we propose an anchor-structure-aware GNN (AS-GNN) model to implement more accurate node distinguishment by capturing the global topology information based on the characteristics of complex networks. Anchor structure is defined as a key sub-graph composed of key nodes and edges in a graph. Taking it as a location reference, we can get the location information of each node in the global topology of graph and carry it into the embedding of nodes. By this way, the node vectors including richer topology information of graph are produced by GNN, and thus the nodes with similar local topologies can be distinguished well. To evaluate the performance of AS-GNN, we compare AS-GNN with some existing baseline models by the experiments of the classic GNN application tasks of link prediction and pairwise node classification on five real-world datasets. The experimental results have confirmed the above claims.

Aqueous Zn batteries are challenged by water decomposition and dendrite growth due to the absence of a dense Zn-ion conductive solid electrolyte interphase (SEI) to inhibit the hydrogen evolution reaction (HER). Here, we design a low-concentration aqueous Zn(OTF) 2 -Zn(NO 3 ) 2 electrolyte to in situ form a robust inorganic ZnF 2 -Zn 5 (CO 3 ) 2 (OH) 6 -organic bilayer SEI, where the inorganic inner layer promotes Zn-ion diffusion while the organic outer layer suppresses water penetration. We found that the insulating Zn 5 (OH) 8 (NO 3 ) 2 ⋅2 H 2 O layer is first formed on the Zn anode surface by the self-terminated chemical reaction of NO 3 − with Zn 2+ and OH − generated via HER, and then it transforms into Zn-ion conducting Zn 5 (CO 3 ) 2 (OH) 6 , which in turn promotes the formation of ZnF 2 as the inner layer. The organic-dominated outer layer is formed by the reduction of OTF − . The in situ formed SEI enables a high Coulombic efficiency (CE) of 99.8 % for 200 h in Ti∥Zn cells, and a high energy density (168 Wh kg −1 ) with 96.5 % retention for 700 cycles in Zn∥MnO 2 cells with a low Zn/MnO 2 capacity ratio of 2:1.

Aqueous Zn batteries are promising energy-storage devices. However, their lifespan is limited by irreversible Zn anodes owing to water decomposition and Zn dendrite growth. Here, we separate aqueous electrolyte from Zn anode by coating a thin MOF layer on anode and filling the pores of MOF with hydrophobic Zn(TFSI)(2)-tris(2,2,2-trifluoroethyl)phosphate (TFEP) organic electrolyte that is immiscible with aqueous Zn(TFSI)(2)-H2O bulk electrolyte. The MOF encapsulated Zn(TFSI)(2)-TFEP forms a ZnF2-Zn-3(PO4)(2)solid electrolyte interphase (SEI) preventing Zn dendrite and water decomposition. The Zn(TFSI)(2)-TFEP@MOF electrolyte protected Zn anode enables a Zn||Ti cell to achieve a high average Coulombic efficiency of 99.1 % for 350 cycles. The highly reversible Zn anode brings a high energy density of 210 Wh kg(-1)(of cathode and anode mass) and a low capacity decay rate of 0.0047 % per cycle over 600 cycles in a Zn||MnO(2)full cell with a low capacity ratio of Zn:MnO(2)at 2:1.

Aqueous Zn batteries are promising energy storage devices for large-scale energy-storage due to low cost and high energy density. However, their lifespan is limited by the water decomposition and Zn dendrite growth. Here, we suppress water reduction and Zn dendrite growth in dilute aqueous electrolyte by adding dimethyl sulfoxide (DMSO) into ZnCl2-H2O, in which DMSO replaces the H2O in Zn2+ solvation sheath due to a higher Gutmann donor number (29.8) of DMSO than that (18) of H2O. The preferential solvation of DMSO with Zn2+ and strong H2O-DMSO interaction inhibit the decomposition of solvated H2O. In addition, the decomposition of solvated DMSO forms Zn12(SO4)3Cl3(OH)15·5H2O, ZnSO3, and ZnS enriched-solid electrolyte interphase (SEI) preventing Zn dendrite and further suppressing water decomposition. The ZnCl2-H2O-DMSO electrolyte enables Zn anodes in Zn||Ti half-cell to achieve a high average Coulombic efficiency of 99.5% for 400 cycles (400 h), and the Zn||MnO2 full cell with a low capacity ratio of Zn:MnO2 at 2:1 to deliver a high energy density of 212 Wh/kg (based on both cathode and anode) and maitain 95.3% of the capacity over 500 cycles at 8 C.

All-solid-state lithium batteries have become an important focus due to their high energy density, long cycling life and excellent safety. As the key part of all-solid-state lithium batteries, solid electrolytes include oxide, sulfide, polymer and composite. The key issues for developing all-solid-sate lithium rechargeable batteries include the design and preparation of solid electrolytes with high ionic conductivities, and solution of the interface resistance between solid electrolytes and electrodes. In this article, the recent developments and relative issues concerning the solid electrolytes and the interface stabilities are reviewed, and the key issues and development direction on all-solid-state lithium batteries are prospected.

Replacement of flammable organic liquid electrolytes with solid Li+ conductors is a promising approach to realize excellent performance of Li metal batteries. However, ceramic electrolytes are either easily reduced by Li metal or penetrated by Li dendrites through their grain boundaries, and polymer electrolytes are also faced with instability on the electrode/electrolyte interface and weak mechanical property. Here, we report a three-dimensional fiber-network-reinforced bicontinuous solid composite electrolyte with flexible Li+-conductive network (lithium aluminum titanium phosphate (LATP)/polyacrylonitrile), which helps to enhance electrochemical stability on the electrode/electrolyte interface by isolating Li and LATP and suppress Li dendrites growth by mechanical reinforcement of fiber network for the composite solid electrolyte. The composite electrolyte shows an excellent electrochemical stability after 15 days of contact with Li metal and has an enlarged tensile strength (10.72 MPa) compared to the pure poly(ethylene oxide)-bistrifluoromethanesulfonimide lithium salt electrolyte, leading to a long-term stability and safety of the Li symmetric battery with a current density of 0.3 mA cm-2 for 400 h. In addition, the composite electrolyte also shows good electrochemical and thermal stability. These results provide such fiber-reinforced membranes that present stable electrode/electrolyte interface and suppress lithium dendrite growth for high-safety all-solid-state Li metal batteries.

常用压缩式封隔器的技术结构普遍是坐封时用解封销钉来锁住整个坐封机构,保持胶筒压缩,解封时通过剪断这个销钉实现胶筒的释放.如果解封销钉小一些,注水过程中外压升高时,销钉常常会自动剪断使封隔器解封;如果加大销钉,每一级封隔器解封力增大,导致管柱上提力逐渐增加,致使解封困难.针对这个问题,通过改变封隔器的技术结构,使坐封机构和解封机构脱离,研究设计了能实现逐级解封的注水井可洗井封隔器,从而改变了常规水井封隔器管柱上提整体管柱、封隔器胶筒同时摩擦套管壁的概念,每级封隔器单独承受上提管柱的解封力,从最上一级封隔器开始依次解封.现场应用表明,逐级解封封隔器实现了管柱在封隔器逐级解封的情况下小载荷起出,从而有效地解决了管柱无法顺利起出的问题,为多层段细分注水提供了技术保障.

Zinc-nickel single flow battery is a promising candidate for energy storage. The low operating current density (low power density) is the critical obstacle for improving its performance and reducing cost. In this paper, we analyzed the polarization distribution (negative polarization, positive polarization and IR drop) at various current densities (20 to 80 mA cm-2) and found that the positive polarization is the main hinder to improve its operating current density without the sacrifice of energy efficiency. Through the design of cell structure and electrode structure, we reduced positive polarization, negative polarization and IR drop to improve the operating current density to realize high power density ZNBs. Meanwhile energy efficiency improved 17 % reaching to 82 % at 80 mA cm-2, which is the highest value ever reported.