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Zinc‐based batteries are emerging as the most promising candidates for large‐scale energy storage devices due to their low cost, high safety, and long‐term storage. However, zinc‐based batteries encounter challenges stemming from undesirable side reactions and zinc dendrites on the anode, as well as dissolution on the cathode. Owing to their extremely small size, substantial surface functional groups, and adjustable structure, carbon dots (CDs) present considerable benefits in augmenting coulombic efficiency, expanding cycle life, and enhancing the rate functionality of zinc‐based batteries. Herein, this review delves into the surface modification and morphological regulation of batteries elements by CDs, CDs composites, and CDs derivatives. Moreover, it systematically encapsulates the application of CDs in zinc‐based batteries, underscoring the pivotal role of CDs in the advancement of electrode technology. Finally, the review highlights the impediments and proposes potential avenues for utilizing CDs in zinc‐based batteries. This review aims to facilitate the development of superior solutions and provide scientific insights into energy storage technologies. [ABSTRACT FROM AUTHOR]

Given the growing environmental and energy problems, developing clean, renewable electrochemical energy storage devices is of great interest. Zn‐air batteries (ZABs) have broad prospects in energy storage because of their high specific capacity and environmental friendliness. The unavailability of cheap air electrode materials and effective and stable oxygen electrocatalysts to catalyze air electrodes are main barriers to large‐scale implementation of ZABs. Due to the abundant biomass resources, self‐doped heteroatoms, and unique pore structure, biomass‐derived catalytically active carbon materials (CACs) have great potential to prepare carbon‐based catalysts and porous electrodes with excellent performance for ZABs. This paper reviews the research progress of biomass‐derived CACs applied to ZABs air electrodes. Specifically, the principle of ZABs and the source and preparation method of biomass‐derived CACs are introduced. To prepare efficient biomass‐based oxygen electrocatalysts, heteroatom doping and metal modification were introduced to improve the efficiency and stability of carbon materials. Finally, the effects of electron transfer number and H2O2 yield in ORR on the performance of ZABs were evaluated. This review aims to deepen the understanding of the advantages and challenges of biomass‐derived CACs in the air electrodes of ZABs, promote more comprehensive research on biomass resources, and accelerate the commercial application of ZABs. [ABSTRACT FROM AUTHOR]

Flexible electronics has emerged as a continuously growing field of study. Two‐dimensional (2D) materials often act as conductors and electrodes in electronic devices, holding significant promise in the design of high‐performance, flexible electronics. Numerous studies have focused on harnessing the potential of these materials for the development of such devices. However, to date, the incorporation of 2D materials in flexible electronics has rarely been summarized or reviewed. Consequently, there is an urgent need to develop comprehensive reviews for rapid updates on this evolving landscape. This review covers progress in complex material architectures based on 2D materials, including interfaces, heterostructures, and 2D/polymer composites. Additionally, it explores flexible and wearable energy storage and conversion, display and touch technologies, and biomedical applications, together with integrated design solutions. Although the pursuit of high‐performance and high‐sensitivity instruments remains a primary objective, the integrated design of flexible electronics with 2D materials also warrants consideration. By combining multiple functionalities into a singular device, augmented by machine learning and algorithms, we can potentially surpass the performance of existing wearable technologies. Finally, we briefly discuss the future trajectory of this burgeoning field. This review discusses the recent advancements in flexible sensors made from 2D materials and their applications in integrated architecture and device design. [ABSTRACT FROM AUTHOR]

Energy serves as the foundational element for all active functions within microrobots. Harvesting devices, such as photovoltaic cells and coils, play a crucial role in converting diverse forms of energy into electricity, while energy storage devices enable uninterrupted operation and liberate microrobots from dependence on external sources. Despite the evident importance of energy, there exists a significant disconnect between the development of energy devices and their integration into microrobotic systems, hampering the deployment of microrobots across diverse fields from agriculture to microsurgery. Here, for transcending the "material for material's sake" focus on simple generic metrics for material optimization, such as energy density, advocating attention to the higher tier transformation of material metrics that determine device‐level performance and so make a meaningful contribution to microrobotic technology is argued. Appropriate metrics for microrobotic swarms challenge the stereotype that tiny energy supplies are impractical; instead, swarms simplify individual microrobotic functions, reducing single energy supply requirements and utilizing swarm energy distribution and management. In addition to essential evaluations of the environmental and social impacts of intelligent microrobotic swarms for their safe and beneficial implementation, research targeting these higher‐tier metrics is crucial to connecting energy material research and microrobot developments effectively. [ABSTRACT FROM AUTHOR]

The shortage and unevenness of fossil energy sources are affecting the development and progress of human civilization. The technology of efficiently converting material resources into energy for utilization and storage is attracting the attention of researchers. Environmentally friendly biomass materials are a treasure to drive the development of new‐generation energy sources. Electrochemical theory is used to efficiently convert the chemical energy of chemical substances into electrical energy. In recent years, significant progress has been made in the development of green and economical electrocatalysts for oxygen reduction reaction (ORR). Although many reviews have been reported around the application of biomass‐derived catalytically active carbon (CAC) catalysts in ORR, these reviews have only selected a single/partial topic (including synthesis and preparation of catalysts from different sources, structural optimization, or performance enhancement methods based on CAC catalysts, and application of biomass‐derived CACs) for discussion. There is no review that systematically addresses the latest progress in the synthesis, performance enhancement, and applications related to biomass‐derived CAC‐based oxygen reduction electrocatalysts synchronously. This review fills the gap by providing a timely and comprehensive review and summary from the following sections: the exposition of the basic catalytic principles of ORR, the summary of the chemical composition and structural properties of various types of biomass, the analysis of traditional and the latest popular biomass‐derived CAC synthesis methods and optimization strategies, and the summary of the practical applications of biomass‐derived CAC‐based oxidative reduction electrocatalysts. This review provides a comprehensive summary of the latest advances to provide research directions and design ideas for the development of catalyst synthesis/optimization and contributes to the industrialization of biomass‐derived CAC electrocatalysis and electric energy storage. [ABSTRACT FROM AUTHOR]

In the present work, we investigate the potential of modified barium titanate (BaTiO3), an inexpensive perovskite oxide derived from earth-abundant precursors, for developing efficient water oxidation electrocatalysts using first-principles calculations. Based on our calculations, Rh doping is a way of making BaTiO3 absorb more light and have less overpotential needed for water to oxidize. It has been shown that a TiO2-terminated BaTiO3 (001) surface is more promising from the point of view of its use as a catalyst. Rh doping expands the spectrum of absorbed light to the entire visible range. The aqueous environment significantly affects the ability of Rh-doped BaTiO3 to absorb solar radiation. After Ti→Rh replacement, the doping ion can take over part of the electron density from neighboring oxygen ions. As a result, during the water oxidation reaction, rhodium ions can be in an intermediate oxidation state between 3+ and 4+. This affects the adsorption energy of reaction intermediates on the catalyst's surface, reducing the overpotential value. [ABSTRACT FROM AUTHOR]

The commercialization of a polymer membrane H2–O2 fuel cell and its widespread use call for the development of cost‐effective oxygen reduction reaction (ORR) nonplatinum group metal (NPGM) catalysts. Nevertheless, to meet the requests for the real‐world fuel cell application and replacing platinum catalysts, it still needs to address some challenges for NPGM catalysts regarding the sluggish ORR kinetics in the cathode and their poor durability in acidic environment. In response to these issues, numerous efforts have been made to study NPGM catalysts both theoretically and experimentally, developed these into the atomically dispersed coordinated metal–nitrogen–carbon (M–N–C) form over the past decades. In this review, we present a comprehensive summary of recent advancements on NPGM catalysts with high activity and durability. Catalyst design strategies in terms of optimizing active‐site density and enhancing catalyst stability against demetalization and carbon corrosion are highlighted. It is also emphasized the importance of understanding the mechanisms and principles behind those strategies through a combination of theoretical modeling and experimental work. Especially, further understanding the mechanisms related to the active‐site structure and the formation process of the single‐atom active site under pyrolysis conditions is critical for active‐site engineering. Optimizing the active‐site distance is the basic principle for improving catalyst activity through increasing the catalyst active‐site density. Theoretical studies for the catalyst deactivation mechanism and modeling stable active‐site structures provide both mechanisms and principles to improve the NPGM catalyst durability. Finally, currently remained challenges and perspectives in the future on designing high‐performance atomically dispersed NPGM catalysts toward fuel cell application are discussed. [ABSTRACT FROM AUTHOR]

Owing to their rich structural chemistry and unique electrochemical properties, vanadium-based materials, especially the low-dimensional ones, are showing promising applications in energy storage and conversion. In this invited review, low-dimensional vanadium-based materials (including 0D, 1D, and 2D nanostructures of vanadium-containing oxides, polyanions, and mixed-polyanions) and their emerging applications in advanced alkali-metal-ion batteries (e.g., Li-ion, Na-ion, and K-ion batteries) are systematically summarized. Future development trends, challenges, solutions, and perspectives are discussed and proposed. Mechanisms and new insights are also given for the development of advanced vanadium-based materials in high-performance energy storage and conversion. [ABSTRACT FROM AUTHOR]

Biomass-derived carbon material has the advantages of economy and high reversible capacity, and become the research hotspot of anode material for sodium-ion batteries (SIBs). Herein, a facile process to prepare carbon material derived from pyrolysis of cotton stalks was reported. As an anode material for SIBs, the sample shows reversible capacity of 76 mA h g−1 after 500 cycles at 0.05 A g−1. In addition, it has specific capacity of 70 mA h g−1 after 1000 cycles at a current density of 0.1 A g−1. This paper provides a new idea to produce carbon material from biomass waste for energy storage and makes a certain contribution to the sustainable development of waste resources. [ABSTRACT FROM AUTHOR]

The slow kinetics of battery-type anode materials for lithium-ion capacitors (LICs) hinder their matching with capacitive-type cathodes. Designing anode materials with greater capacity and improved rate performance is a key to solving this challenge. Here, we fabricated one-dimensional N, S co-doped carbon encapsulated Fe7S8 nanorods to realize fast lithium storage kinetics and stable cycling performance. The matched Fe7S8@C//AC LICs achieved an extraordinary energy density of 101 Wh kg-1 and a power density of 3927 W kg-1. [ABSTRACT FROM AUTHOR]

Highly efficient and stable iron electrodes are of great significant to the development of iron-air battery (IAB). In this paper, iron nanoparticle-encapsulated C-N composite (NanoFe@CN) was synthesized by pyrolysis using polyaniline as the C-N source. Electrochemical performance of the NanoFe@CN in different electrolytes (alkaline, neutral, and quasi-neutral) was investigated via cyclic voltammetry (CV). The IAB was assembled with NanoFe@CN as the anode and IrO2 + Pt/C as the cathode. The effects of different discharging/charging current densities and electrolytes on the battery performance were also studied. Neutral K2SO4 electrolyte can effectively suppress the passivation of iron electrode, and the battery showed a good cycling stability during 180 charging/discharging cycles. Compared to the pure nano-iron (NanoFe) battery, the NanoFe@CN battery has a more stable cycling stability either in KOH or NH4Cl + KCl electrolyte. [ABSTRACT FROM AUTHOR]

With the rapid development of plastic production and consumption globally, the amount of post-consumer plastic waste has reached levels that have posed environmental threats. Considering the substantial CO2 emissions throughout the plastic lifecycle from material production to its disposal, photocatalysis is considered a promising strategy for effective plastic recycling and upcycling. It can upgrade plastics into value-added products under mild conditions using solar energy, realizing zero carbon emissions. In this paper, we explain the basics of photocatalytic plastic reformation and underscores plastic feedstock reformation pathways into high-value-added products, including both degradation into CO2 followed by reformation and direct reformation into high-value-added products. Finally, the current applications of transforming plastic waste into fuels, chemicals, and carbon materials and the outlook on upcycling plastic waste by photocatalysis are presented, facilitating the realization of carbon neutrality and zero plastic waste. [ABSTRACT FROM AUTHOR]

Abstract Flexible electronics has emerged as a continuously growing field of study. Two‐dimensional (2D) materials often act as conductors and electrodes in electronic devices, holding significant promise in the design of high‐performance, flexible electronics. Numerous studies have focused on harnessing the potential of these materials for the development of such devices. However, to date, the incorporation of 2D materials in flexible electronics has rarely been summarized or reviewed. Consequently, there is an urgent need to develop comprehensive reviews for rapid updates on this evolving landscape. This review covers progress in complex material architectures based on 2D materials, including interfaces, heterostructures, and 2D/polymer composites. Additionally, it explores flexible and wearable energy storage and conversion, display and touch technologies, and biomedical applications, together with integrated design solutions. Although the pursuit of high‐performance and high‐sensitivity instruments remains a primary objective, the integrated design of flexible electronics with 2D materials also warrants consideration. By combining multiple functionalities into a singular device, augmented by machine learning and algorithms, we can potentially surpass the performance of existing wearable technologies. Finally, we briefly discuss the future trajectory of this burgeoning field. This review discusses the recent advancements in flexible sensors made from 2D materials and their applications in integrated architecture and device design.

Abstract The shortage and unevenness of fossil energy sources are affecting the development and progress of human civilization. The technology of efficiently converting material resources into energy for utilization and storage is attracting the attention of researchers. Environmentally friendly biomass materials are a treasure to drive the development of new‐generation energy sources. Electrochemical theory is used to efficiently convert the chemical energy of chemical substances into electrical energy. In recent years, significant progress has been made in the development of green and economical electrocatalysts for oxygen reduction reaction (ORR). Although many reviews have been reported around the application of biomass‐derived catalytically active carbon (CAC) catalysts in ORR, these reviews have only selected a single/partial topic (including synthesis and preparation of catalysts from different sources, structural optimization, or performance enhancement methods based on CAC catalysts, and application of biomass‐derived CACs) for discussion. There is no review that systematically addresses the latest progress in the synthesis, performance enhancement, and applications related to biomass‐derived CAC‐based oxygen reduction electrocatalysts synchronously. This review fills the gap by providing a timely and comprehensive review and summary from the following sections: the exposition of the basic catalytic principles of ORR, the summary of the chemical composition and structural properties of various types of biomass, the analysis of traditional and the latest popular biomass‐derived CAC synthesis methods and optimization strategies, and the summary of the practical applications of biomass‐derived CAC‐based oxidative reduction electrocatalysts. This review provides a comprehensive summary of the latest advances to provide research directions and design ideas for the development of catalyst synthesis/optimization and contributes to the industrialization of biomass‐derived CAC electrocatalysis and electric energy storage.

Abstract The commercialization of a polymer membrane H2–O2 fuel cell and its widespread use call for the development of cost‐effective oxygen reduction reaction (ORR) nonplatinum group metal (NPGM) catalysts. Nevertheless, to meet the requests for the real‐world fuel cell application and replacing platinum catalysts, it still needs to address some challenges for NPGM catalysts regarding the sluggish ORR kinetics in the cathode and their poor durability in acidic environment. In response to these issues, numerous efforts have been made to study NPGM catalysts both theoretically and experimentally, developed these into the atomically dispersed coordinated metal–nitrogen–carbon (M–N–C) form over the past decades. In this review, we present a comprehensive summary of recent advancements on NPGM catalysts with high activity and durability. Catalyst design strategies in terms of optimizing active‐site density and enhancing catalyst stability against demetalization and carbon corrosion are highlighted. It is also emphasized the importance of understanding the mechanisms and principles behind those strategies through a combination of theoretical modeling and experimental work. Especially, further understanding the mechanisms related to the active‐site structure and the formation process of the single‐atom active site under pyrolysis conditions is critical for active‐site engineering. Optimizing the active‐site distance is the basic principle for improving catalyst activity through increasing the catalyst active‐site density. Theoretical studies for the catalyst deactivation mechanism and modeling stable active‐site structures provide both mechanisms and principles to improve the NPGM catalyst durability. Finally, currently remained challenges and perspectives in the future on designing high‐performance atomically dispersed NPGM catalysts toward fuel cell application are discussed.

The energy transition is a global process and requires new import routes for energy demanding countries like Germany. Countries with great potential for renewable energy production may become key players in the global energy transition. In this contribution, we assess the potential of the liquid organic hydrogen carrier (LOHC) technology. LOHCs enable an energy‐efficient storage and transportation using existing infrastructure for liquid hydrocarbons. Exemplary roles of LOHCs in the German energy landscape are illustrated. Lastly, LOHC demonstration projects in Germany are presented. [ABSTRACT FROM AUTHOR]

Advanced electrocatalysts can enable the widespread implementation of clean energy technologies. This paper reviews an emerging class of electrocatalytic materials comprising holey two‐dimensional free‐standing Pt‐group metal (h‐2D‐PGM) nanosheets, which are categorically challenging to synthesize but inherently rich in all the qualities necessary to counter the kinetic and thermodynamic challenges of an electrochemical conversion process with high catalytic efficiency and stability. Although the 2D anisotropic growth of typical nonlayered metal crystals has succeeded and partly improved their atom‐utilization efficiency, regularly distributed in‐planar porosity can further optimize three critical factors that govern efficient electrocatalysis process: mass diffusion, electron transfer, and surface reactivity. However, producing such advanced morphological features within h‐2D‐PGMs is difficult unless they are specially engineered using approaches such as templating or kinetic ramification during 2D growth or controlled etching of preformed 2D‐PGM solids. Therefore, this review highlighting the successful fabrication of various porous PGM nanosheets and their electrocatalytic benefits involving smart nanoscale features could inspire next‐generation scientific and technological innovations toward securing a sustainable energy future. [ABSTRACT FROM AUTHOR]

Exploration of significantly active functional materials is highly valued for designing efficient electrochemical energy devices. 2D‐covalent organic frameworks (2D‐COF) have attracted significant interest in the context of important electrochemical applications due to their tunable structural and electronic properties, high thermal/chemical stability, and their carbon‐based motifs. The present review highlights the strategies and properties of modifying 2D‐COF electronically in detail and their prospects in electrochemical devices. The review clearly explains the electronic actuation methods of the COF skeletons by various synthetic and post‐synthetic strategies. The review crucially elucidates the importance of electroactive 2D‐COF as emerging functional materials in practical applications of electrochemical energy conversion devices. The review concludes by summarizing the effective strategies of 2D‐COF in improving electrocatalytic applications and suggests future research scope. The review orients the electroactive 2D‐COFs for critical analysis as advanced functional materials for a sustainable and reliable future. [ABSTRACT FROM AUTHOR]

MXene, as a new type of two-dimensional material, has attracted much interest since it was discovered in 2011. However, only few articles discussed the effect of MXene flake size on its electrochemical performance. Here, a sand milling way is explored to produce nano-size MXene and the MILD method is used to prepare micron-size MXene (1 μm) as a comparison. Meanwhile, a mask-assisted interdigital micro-supercapacitors is prepared to explore the dependence of the electrochemical properties of MXene on their flake size. We show that nano-size MXene (200 nm) has a higher ionic conductivity as compared to normal micron-size MXene (1 μm). On the contrary, the larger flake size has higher electrical conductivities. As a result, the capacitance of micron-size MXene is better than nano-size MXene (200 nm) because the electrical conductivities are dominant. This research is helpful for further understanding of the influence of MXene flake size on its electrochemical performance. [ABSTRACT FROM AUTHOR]

The recycling of key components in waste lithium-ion batteries (LIBs) is an important route to make up for the shortage of battery materials. Metal separation and purification is an important step. It is of great significance to propose an efficient and green separation technology. In this paper, an electrochemical precipitation method was applied to metal separation from spent LiNi0.5Mn1.5O4 cathode material. The Li and metal elements were effective separated and the precipitates were then used as precursor to synthesize high-performance R–O3-NaNFM cathode material for sodium-ion batteries. The R–O3-NaNFM exhibits excellent electrochemical cycling stability. The capacity retains 71.3 mAh g−1 after a long-term cycling of 200 times at 1 C. This method offers a referable strategy of the recycling for the waste cathode material in spent LIBs.

High-entropy oxides (HEOs) are gaining prominence in the field of electrochemistry due to their distinctive structural characteristics, which give rise to their advanced stable and modifiable functional properties. This review presents fundamental preparations, incidental characterizations, and typical structures of HEOs. The prospective applications of HEOs in various electrochemical aspects of electrocatalysis and energy conversion-storage are also summarized, including recent developments and the general trend of HEO structure design in the catalysis containing oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), supercapacitors (SC), lithium-ion batteries (LIBs), solid oxide fuel cells (SOFCs), and so forth. Moreover, this review notes some apparent challenges and multiple opportunities for the use of HEOs in the wide field of energy to further guide the development of practical applications. The influence of entropy is significant, and high-entropy oxides are expected to drive the improvement of energy science and technology in the near future.

The need for energy is rising quickly, and the usage of fossil fuels is contributing to the greenhouse effect and environmental pollution, both of which are raising public concerns. The development of novel electrochemical energy storage techniques as well as the creation of cleaner, more sustainable energies have both become highly researched topics as a result of this condition. New functional materials are being investigated for the advancement of energy storage. High entropy hydroxides (HEH) have lately been emerged as promising electrocatalyst for universal water splitting reactions, which are central for solid oxide fuel cells, hydrogen production and metal-air batteries. In this work, a cost-effective and scalable fabrication method was applied to fabricate several HEH on Nickel foam through single-step electrodeposition technique. Results showed that high-entropy FeCoNiMnOOH exhibits excellent OER activity with a low overpotential of 151 mV at current density of 100 mA cm−2, which is associated with it’s defective structure.

In the present work, we investigate the potential of modified barium titanate (BaTiO3), an inexpensive perovskite oxide derived from earth-abundant precursors, for developing efficient water oxidation electrocatalysts using first-principles calculations. Based on our calculations, Rh doping is a way of making BaTiO3 absorb more light and have less overpotential needed for water to oxidize. It has been shown that a TiO2-terminated BaTiO3 (001) surface is more promising from the point of view of its use as a catalyst. Rh doping expands the spectrum of absorbed light to the entire visible range. The aqueous environment significantly affects the ability of Rh-doped BaTiO3 to absorb solar radiation. After Ti→Rh replacement, the doping ion can take over part of the electron density from neighboring oxygen ions. As a result, during the water oxidation reaction, rhodium ions can be in an intermediate oxidation state between 3+ and 4+. This affects the adsorption energy of reaction intermediates on the catalyst’s surface, reducing the overpotential value.

Investigating the electrochemical behavior of the CNT/Fe2O3 nanocomposite revealed compelling insights. TEM analysis confirmed the uniform attachment of Fe2O3 nanoparticles to the surface of CNTs. Consequently, in the three-electrode system, the CNT/Fe2O3 nanocomposite hybrid electrode exhibited impressive electrochemical performance. Achieving a high capacitance of approximately 512 F/g at a current density of 1 A/g, the CNT/Fe2O3 nanocomposite electrode showcased a remarkable energy density of 29.5 Wh/kg at a power density of 2.8 kW/kg. The exceptional electrochemical properties of CNT Fe2O3 nanocomposites position them as promising electrode materials for supercapacitors.

Micron scale Silicon (Si) powders embedded with nanoparticles were fabricated by dealloying methods and extracted from antimony (Sb)-inoculated Aluminum-10 wt.% Silicon (Al-10Si) alloys. From TEM observation, most of these nanoparticles were not connected with adjacent ones, with radii ranging from 3 to 10 nm. The cycling performance of Si powders with nanoparticles delivered a specific capacity of 105.2 mAh/g after 30 cycles at a current density of 0.05 mA/g, which was 40% higher than those without nanoparticles, due to the formation of preferential channels for electrolytes. Therefore, the micron size Si structures with nanoparticles have shown a potential as highperformance anode materials for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Herein, ethylene-vinyl acetate copolymer/styrene ethylene butylene styrene (EVA/SEBS) blend foam with wide effective damping temperature range (ΔT) was prepared via supercritical nitrogen. The influence of the ratio of EVA and SEBS on the foaming and damping properties was studied. ΔT gradually widened into the high temperature region with the increase of SEBS content, and higher SEBS gave denser and more uniform cell structure and reduced the density of the blend foam. When the content of SEBS was 40 phr, the density of the blended foam was 0.185 g/cm³, and the ΔT was -3~54°C. These damping foams were lightweight and this work showed that damping performance could be controlled by simply adjusting blend content, which is of great significance to broaden the application environment of damping materials. [ABSTRACT FROM AUTHOR]

Zinc–air batteries (ZABs) have garnered significant interest as a viable substitute for lithium-ion batteries (LIBs), primarily due to their impressive energy density and low cost. However, the efficacy of zinc–air batteries is heavily dependent on electrocatalysts, which play a vital role in enhancing reaction efficiency and stability. This scholarly review article highlights the crucial significance of electrocatalysts in zinc–air batteries and explores the rationale behind employing Fe-Co-Ni-Zn-based metal–organic framework (MOF)-derived hybrid materials as potential electrocatalysts. These MOF-derived electrocatalysts offer advantages such as abundancy, high catalytic activity, tunability, and structural stability. Various synthesis methods and characterization techniques are employed to optimize the properties of MOF-derived electrocatalysts. Such electrocatalysts exhibit excellent catalytic activity, stability, and selectivity, making them suitable for applications in ZABs. Furthermore, they demonstrate notable capabilities in the realm of ZABs, encompassing elevated energy density, efficacy, and prolonged longevity. It is imperative to continue extensively researching and developing this area to propel the advancement of ZAB technology forward and pave the way for its practical implementation across diverse fields. [ABSTRACT FROM AUTHOR]

Bismuth sulfide (Bi2S3) with micro/nanostructures as an important semiconductor material has attracted considerable attention due to its high ionic conductance, high photoelectric conversion efficiency, and large absorption coefficient, which is widely applied in the areas of photocatalysis, energy conversion, sensors, biomedicine, and pollutant disposal. Up to now, various strategies are reported for the morphology‐controlled synthesis of micro‐nanoscale Bi2S3 and Bi2S3‐based materials via manipulating the thermodynamics and kinetics in the chemical fabricating process. However, the Bi2S3 with designed shapes still remains to be developed to well adapt these diverse usages. To conclude, the designed preparation strategies, advanced applications, current challenges, and future expectations of Bi2S3 are discussed to provide some potential suggestions for further promotion of Bi2S3 functional materials. [ABSTRACT FROM AUTHOR]

The present work demonstrates electrochemical performance of cobalt phosphate (CP) thin films prepared by chemical bath deposition technique. The prepared (CP) films are of monoclinic phase with highly preferred orientation along (240) plane. Morphology studies on the CP films with different concentration reveal nanospheres along with the growth of intermediate nanosheets. The electrode with 3.5 M cobalt concentration (CP3) offers more active sites and enhanced electrochemical performance as compared to the other two electrodes, viz, CP1 and CP2 which contain lower concentration of cobalt. The CP3 electrode shows maximum specific capacitance of 678 Fg−1 at a scan rate of 10 mVs−1 and 90.46% capacitive retention after 10,000 cycles. The impact of capacitive and diffusive contributions to the total capacity of the electrodes is studied by employing Trasatti and Dunn's model. The results on the study of CP thin film electrodes establish their potential for the growing energy storage applications. [ABSTRACT FROM AUTHOR]

The development of electrode materials for supercapacitors is really progressive and it still poses a huge challenge for researchers in many aspects. Doping of transition metals is indeed effective method because fast interfacial charge transfer kinetics has demonstrated their potential supercapacitive nature. The present work submits the structural, morphological and electrochemical performances of nickel pyrophosphate (Ni2P2O7) and manganese doped nickel pyrophosphate (Mn‐Ni2P2O7) thin film electrodes synthesized by chemical bath deposition method. The crystal structure of Ni2P2O7 obtained through X‐ray diffraction (XRD) is confirmed to be monoclinic which remains unaltered despite of Mn doping concentration. Morphological studies reveal that crystalline phase of Mn is intimately anchored on the surface of Ni2P2O7 which is beneficial for better charge transfer between transition metal and transition metal phosphates. A specific capacitance value of 603 F/g is obtained for 3 M concentration of Mn doped Ni2P2O7 from galvanostatic charge‐discharge curve at current density 1 A/g. This value is noticeably higher than what is obtained for the pure Ni2P2O7 indicating that Mn doping enhances the electrochemical performance of Ni2P2O7 thin films. [ABSTRACT FROM AUTHOR]

The ice-templated method (ITM) has drawn significant attention to the improvement of the electrochemical properties of various materials. The ITM approach is relatively straightforward and can produce hierarchically porous structures that exhibit superior performance in mass transfer, and the unique morphology has been shown to significantly enhance electrochemical performance, making it a promising method for energy storage and conversion applications. In this review, we aim to present an overview of the ITM and its applications in the electrochemical energy storage and conversion field. The fundamental principles underlying the ITM will be discussed, as well as the factors that influence the morphology and properties of the resulting structures. We will then proceed to comprehensively explore the applications of ITM in the fabrication of high-performance electrodes for supercapacitors, batteries, and fuel cells. We intend to find the key advances in the use of ITM and evaluate its potential to overcome the existing challenges in the development of efficient energy storage and conversion systems. [ABSTRACT FROM AUTHOR]

Despite the high theoretical capacity of iron-based anode materials, they still perform poorly in electrical conductivity and volume expansion during the charge/discharge process, which can reduce battery life and cause deterioration in cycle performance. In the present study, iron-based metal–organic frameworks are synthesized through a simple co-precipitation method, and then heat-treated as a self-sacrificing template to obtain carbon-coated Fe3O4 of a porous ortho-octahedral structure. As revealed by electrochemical performance studies, this material maintains a high specific capacity, showing a reversible capacity of 1063 mAh/g and 896 mAh/g after 300 cycles at a current density of 0.5 A/g and 1 A/g. By analyzing the functional mechanism of surface carbon coating, it is demonstrated that the fast ion migration and high electrical conductivity required for fast charging and discharging are ensured by the octahedral and hierarchical void structure of the carbon framework. This study thus provides a reference for the design of high-performance electrode materials. [ABSTRACT FROM AUTHOR]

Prussian blue is a potential cathode candidate for sodium-ion batteries because of inexpensiveness and high theoretical capacity, while the poor rate performance hinders its widely practical application. In this work, the Prussian blue is directly grown on poly3,4-ethylenedioxythiophene decorated multi-wall carbon nanotubes (denoted as PB/CNT@PEDOT), where the CNT@PEDOT can provide improved electrical conductivity and lower the size of PB. Thus, the PB/CNT@PEDOT shows a discharge capacity of 85 mAh g−1 after 100 cycles at 0.2C. Compare to PB and PB/CNT, the PB/CNT@PEDOT delivers enhanced rate capability with 90 mAh g−1 retention at 5C. [ABSTRACT FROM AUTHOR]

Highlights Two-dimensional transition metal borides have high mechanical stability, high charge carrier mobility and great electrochemical performance. The potential applications of two-dimensional transition metal borides in the direction of energy conversion and storage have not been systematically reviewed. We summarize the research on the role of two-dimensional transition metal borides in catalysis and ion batteries, and put forward the new opportunities in preparation and biotechnology.

As the lightest family member of the transition metal disulfides (TMDs), TiS 2 has attracted more and more attention due to its large specific surface area, adjustable band gap, good visible light absorption, and good charge transport properties. In this review, the recent state-of-the-art advances in the syntheses and applications of TiS 2 in energy storage, electronic devices, and catalysis have been summarized. Firstly, according to the physical presentation of the TiS 2 synthesis reaction, it can be divided into a solid phase synthesis, a liquid phase synthesis and a gas phase synthesis. Secondly, we summarize the applications of TiS 2 in energy storage, electronic devices and catalytic: (1) The applications of TiS 2 nanostructure in energy storage direction from the aspects of Li-ion battery (LIB), Li–S battery (LSB), Na-ion battery (NIB), K-ion battery (KIB), Mg-ion battery (MIB), solar cells and hydrogen storage; (2) The applications of TiS 2 nanostructures in various electronic devices from thermoelectric devices, high power lasers and flexible devices; (3) Applications based on energy catalysis and environmental catalysis. Based on the various synthetic technologies and wide applications of TiS 2 , we firmly believe that the challenges of TiS 2 will be solved and become a hot star material in the future. Finally, we discuss the future scope and the current challenges arising from this fascinating material. [ABSTRACT FROM AUTHOR]

An extremely stable, energy‐dense (53.6 Ah L−1, 2 m transferrable electrons), low crossover (permeability of <1 × 10−13 cm2 s−1 using Nafion 212 (Nafion is a trademark polymer from DuPont)), and potentially inexpensive anthraquinone with 2‐2‐propionate ether anthraquinone structure (abbreviated 2‐2PEAQ) is synthesized and extensively evaluated under practically relevant conditions for use in the negolyte of an aqueous redox flow battery. 2‐2PEAQ shows a high stability with a fade rate of 0.03–0.05% per day at different applied current densities, cut‐off voltage windows, and concentrations (0.1 and 1.0 m) in both a full cell paired with a ferro/ferricyanide posolyte as well as a symmetric cell. 2‐2PEAQ is further shown to have extreme long‐term stability, losing only ≈0.01% per day when an electrochemical rejuvenation strategy is employed. From post‐mortem analysis (nuclear magnetic resonance (NMR), liquid chromatography–mass spectrometry (LC‐MS), and cyclic voltammetry (CV)) two degradation mechanisms are deduced: side chain loss and anthrone formation. 2‐2PEAQ with the ether linkages attached on carbons non‐adjacent to the central ring is found to have three times lower fade rate compared to its isomer with ether linkages on the carbon adjacent to the central quinone ring. The present study introduces a viable negolyte candidate for grid‐scale aqueous organic redox flow batteries. [ABSTRACT FROM AUTHOR]

MgO/few-layer graphene (FLG) nanocomposite is proven as an excellent electrode in aqueous supercapacitors (AS). The synergy between the pseudo-capacitive MgO and the double-layer charging nature of FLG that enhances the supercapacitors' specific capacitance (SC) was successfully tested. The SC could be further enhanced by combining MgO/FLG with a third component, such as a conducting polymer (with a Faradaic type of charge storage capability). Herein, such an attempt has been made. MgO/FLG was uniformly filled in polyaniline (PANI) by using a simple in situ polymerization method. X-ray diffraction, electron microscopy, and Raman and Fourier transform infrared spectroscopic analyses clearly showed the formation of a ternary nanocomposite constituted by MgO, FLG and PANI. As anticipated, the ternary nanocomposite (MgO/FLG-filled PANI (MFP)) exhibited an enhanced SC (compared to MgO/FLG) when tested as electrode material in AS. The MFP composite was evaluated for SC using a 3-electrode system. MFP composite exhibited a maximum SC of 347 F g−1 when tested at a scan rate of 5 mV s−1 using 1 M aqueous H2SO4 as the electrolyte. The electrode material assumable with symmetric capacitance achieved a maximum capacitance of 396 F g−1 at a current density of 1 A g−1 and showed a capacitance retention of 81%. In contrast, MgO/FLG exhibited much lower values under similar testing conditions. [ABSTRACT FROM AUTHOR]

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The electrochemical performance of the supercapacitors essentially relies on electrode materials. The transition metal phosphates have drawn much attraction as electrode material for energy storage in supercapacitors. Ni2P2O7 (NP) thin film electrodes are synthesized through economic and reproducible chemical bath deposition technique by varying Ni concentration 0.05 M, 0.1 M, and 0.15 M. The X-ray diffraction pattern reveals the formation of monoclinic structured NP thin films with high crystallinity. The microsphere like morphology in which agglomerated microspheres assembled in large number with average particle size decreases with increase of molar concentration is visualized by scanning electron microscopy. The cyclic voltammetry (CV) analysis demonstrates the pseudocapacitive nature in NP thin film electrodes. NP3 electrode exhibits the high specific capacitance of 588 F/g at current density 1 A/g evaluated by galvanostatic charge-discharge (GCD) profile. The cyclic stability test of NP3 enunciates its capacitive retention as 95.50% after 2500 cycles. The results indicate that NP3 is an exemplary supercapacitor candidate and it would lead to productive research in future energy storage applications. [ABSTRACT FROM AUTHOR]

The combination of transition metal compounds and carbon materials is considered effective in optimizing electrode material performance. In this work, some simple methods are used to embed bimetallic phosphides into carbon material frameworks to form heterostructures. The process includes the in situ growth of cobalt-based zeolitic imidazole frameworks on rGO, the formation of bimetallic hydroxides by Ni2+ etching, and further high-temperature phosphating to form a NiCoP/rGO hollow nanocomposite. Benefiting from the synergistic effect between NiCoP and rGO, NiCoP/rGO-20 exhibits the best electrochemical properties, has a high specific capacity of 250.9 mAh g−1 at a current density of 1 A g–1, and has good rate performance (62.7% retention at 10 A g–1). Furthermore, a hybrid supercapacitor was assembled with NiCoP/rGO-20 as the positive electrode and activated carbon (AC) as the negative electrode. The NiCoP/rGO-20//AC HSC device has a high energy density of 60.6 Wh kg–1 at a power density of 749 W kg–1 as well as excellent cycling stability with 83.7% capacitance retention after 10,000 cycles at 10 A g–1. This work provides a new strategy for the development of high-performance energy storage composites. [ABSTRACT FROM AUTHOR]

Mn3O4@CC electrodes were synthesized via a fast one-step molten salt method for flexible quasi-solid symmetric supercapacitors. Mn3O4 grows rapidly in a high polarity molten salt system and strongly anchors to carbon cloth. The molten salt method can realize sodion embedded in Mn3O4 and then improve the conductivity and capacitance. The results show that the Na-0.9-based supercapacitor exhibits a high capacitance of 1225.7 mF cm−2 at 5 mA cm−2. The preparation method, design strategy on structure of composition in this work will provide a novel route to realize high-performance flexible supercapacitors.

Corn by-products have been widely studied as a precursor of biomass carbon in energy storage systems. Without further doping or coating processes corn silk can achieve a high electrochemical performance when used as an anode of sodium and potassium ion batteries. Nonetheless, there is no report about corn silk used as a cathode for lithium-sulfur batteries. In this work, corn silk was made into porous carbon and used as sulfur scaffolds and modified materials for commercial separator in lithium-sulfur batteries. Corn silk possesses a natural pipe shape which grants the porous carbon a high specific surface area. With a simple dissolution crystallization method approximately 80% of the sulfur could be easily accommodated onto the porous carbon. The hierarchic pores not only limited the particle size of the sulfur to nanometers, but also buffered the volume expansion of sulfur and absorbed it tightly. Furthermore, with an ultralight porous carbon modified separator, significant improvement was achieved in the utilization of sulfur, cycling stability and alleviation of the polysulfide shuttling efficiently. The batteries delivered a specific capacity of 1290 mAh g-1 in the first discharge and 746 mAh g-1 after 100 cycles. The good electrochemical performance can be ascribed to the rational design of battery configuration.

Micro/nano metal–organic frameworks (MOFs) have attracted significant attention in recent years due to their numerous unique properties, with many synthetic methods and strategies being reported for constructing MOFs with specific micro/nano structures. In addition, the design of micro/nano MOFs for energy storage and conversion applications and the study of the structure–activity relationship have also become research hotspots. Herein, a comprehensive overview of the recent progress on micro/nano MOFs is presented. We begin with a brief introduction to the various synthesis methods for controlling the morphology of micro/nano MOFs. Subsequently, the structure-dependent properties of micro/nano MOFs as electrode materials or catalysts in terms of batteries, supercapacitors, and catalysis are discussed. Finally, the remaining challenges and future perspectives in this field are presented. Overall, this review is expected to inspire the design of advanced micro/nano MOFs for efficient energy storage and conversion technologies.

The leakage behavior of ferroelectric film has an important effect on energy storage characteristics. Understanding and controlling the leakage mechanism of ferroelectric film at different temperatures can effectively improve its wide-temperature storage performance. Here, the structures of a 1 mol% SiO2-doped BaZr0.35Ti0.65O3 (BZTS) layer sandwiched between two undoped BaZr0.35Ti0.65O3 (BZT35) layers was demonstrated, and the leakage mechanism was analyzed compared with BZT35 and BZTS single-layer film. It was found that interface-limited conduction of Schottky (S) emission and the Fowler-Nordheim (F-N) tunneling existing in BZT35 and BZTS films under high temperature and a high electric field are the main source of the increase of leakage current and the decrease of energy storage efficiency at high temperature. Only an ohmic conductive mechanism exists in the whole temperature range of BZT35/BZTS/BZT35(1:1:1) sandwich structure films, indicating that sandwich multilayer films can effectively simulate the occurrence of interface-limited conductive mechanisms and mention the energy storage characteristics under high temperature. [ABSTRACT FROM AUTHOR]

Highlights: Two-dimensional transition metal borides have high mechanical stability, high charge carrier mobility and great electrochemical performance. The potential applications of two-dimensional transition metal borides in the direction of energy conversion and storage have not been systematically reviewed. We summarize the research on the role of two-dimensional transition metal borides in catalysis and ion batteries, and put forward the new opportunities in preparation and biotechnology. As a flourishing member of the two-dimensional (2D) nanomaterial family, MXenes have shown great potential in various research areas. In recent years, the continued growth of interest in MXene derivatives, 2D transition metal borides (MBenes), has contributed to the emergence of this 2D material as a latecomer. Due to the excellent electrical conductivity, mechanical properties and electrical properties, thus MBenes attract more researchers' interest. Extensive experimental and theoretical studies have shown that they have exciting energy conversion and electrochemical storage potential. However, a comprehensive and systematic review of MBenes applications has not been available so far. For this reason, we present a comprehensive summary of recent advances in MBenes research. We started by summarizing the latest fabrication routes and excellent properties of MBenes. The focus will then turn to their exciting potential for energy storage and conversion. Finally, a brief summary of the challenges and opportunities for MBenes in future practical applications is presented. [ABSTRACT FROM AUTHOR]