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Hydrogen‐bonded organic frameworks (HOFs) are considered as potential choice for future energy storage systems due to their adjustable chemistry, environment friendliness, and cost‐effectiveness. In this study, structurally stabilized and aldehyde‐tuned hydrogen‐bonded organic frameworks (HOFs‐8) are designed and prepared to contain arrayed electronegative sites for sodium‐ion storage. Benefitting from the flexible hydrogen bond and unique structural symmetry, HOFs‐8 can achieve efficient utilization of the active sites and fast transport of sodium ions and electrons. The HOFs‐8 electrode exhibits an impressive lifespan of 5000 cycles at 3.66 A g−1 (20 C). In situ Fourier Transform infrared spectroscopy (in situ FT‐IR) and ex situ X‐ray Photoelectron Spectroscopy (ex situ XPS) analyses are performed to illustrate the mechanism of sodium‐ion storage involving aldehyde‐tuned C═O. Additionally, flexible hydrogen bonds in HOFs materials with unique structural symmetries are investigated to elucidate the mechanism of hydrogen bonding for improving their electrochemical properties. Density functional theory (DFT) simulations verified that HOFs‐8 has excellent Na+ diffusion kinetics, enabling it to demonstrate outstanding rate capability. This work offers insight into the design of new electrodes and improved HOFs, which are expected to have tremendous potential in energy storage systems. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries (SIBs) with wide operating temperature are regarded as promising candidates for large‐scale energy storage systems. However, SIBs operating under elevated temperature aggravate the electrolyte decomposition with unstable cathode‐electrolyte interphase (CEI), causing a rapid capacity degradation. Herein, anion receptor tris(pentafluorophenyl)borane (TPFPB) is selected as electrolyte additive to construct robust NaF‐rich CEI. The strong interactions between anion and TPFPB via the electron‐deficient boron atoms weaken ClO4− solvation and promote the coordination capability between solvents and Na+ cations, demonstrating greatly improved oxidative stability. Na3V2(PO4)3 cathode in TPFPB‐containing electrolyte delivers long‐term stability with a capacity retention of 86.9% after 100 cycles at a high cut‐off voltage of 4.2 V (vs. Na+/Na) and a high temperature of 60 °C. Besides, TPFPB also works well with enhanced performance over a temperature range from −30 to 60 °C. This study proposes a prospective method by manipulating the solvation chemistry for constructing high‐temperature rechargeable SIBs. [ABSTRACT FROM AUTHOR]

Given the merits of affordable cost, superior low‐temperature performance, and advanced safe properties, sodium‐ion batteries (SIBs) have exhibited great development potential in large scale energy storage applications. Among various emerging carbonaceous anode materials applied for SIBs, hard carbon (HC) has recently gained significant attention regarding their relatively low cost, wide availability, and optimal overall performance. However, the insufficient initial Coulombic efficiency (ICE) of HC is the main bottlenecks, which is inevitably hindering their further commercial applications. Herein, an in‐depth holistic exposition about the reasons causing the unsatisfied ICE and the recent advances on effective improvement strategies are comprehensively summarized in this review, which have been divided into two aspects including the intrinsic property (degree of graphitization, pore structure, defect, et al.) and the extrinsic factor (electrolyte, electrode materials, et al.). In addition, future prospects and perspectives on HC to enable practical application in SIBs are also briefly outlined. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries (SIBs) present great appeal in various energy storage systems, especifically for stationary grid storage, on account of the abundance of sources and low cost. Unfortunately, the commercialization of SIBs is mainly limited by available electrode materials, especially for the cathodes. Prussian blue analogs (PBAs), emerge as a promising alternative for their structural feasibility in the application of SIBs. Decreasing the defects (vacancies and coordinated water) is an effective strategy to achieve superior electrochemical performance during the synthetic processes. Herein, we summarize crystal structures, synthetic methods, electrochemical mechanisms, and the influences of synthesis conditions of PBAs in detail. This comprehensive overview on the current research progresses of PBAs will give guides and directions to solve the existing problems for their application in SIBs. [ABSTRACT FROM AUTHOR]

The development of large‐scale energy storage systems (ESSs) aimed at application in renewable electricity sources and in smart grids is expected to address energy shortage and environmental issues. Sodium‐ion batteries (SIBs) exhibit remarkable potential for large‐scale ESSs because of the high richness and accessibility of sodium reserves. Using low‐cost and abundant elements in cathodes with long cycling stability is preferable for lowering expenses on cathodes. Many investigated cathodes for SIBs are dogged by structural and morphology changes, unstable interphases between the cathode and the electrolyte, and air sensitivity, causing unsatisfactory cycling performance. Therefore, understanding the mechanism of capacity degeneration in depth and developing precise solutions are critical for designing low‐cost cathodes that are highly stable under cycling. Herein, recent progress in long‐cycle‐life and low‐cost cathodes for SIBs is focused on, and a comprehensive discussion of the key points in SIBs toward large‐scale applications is provided. The roots of the unstable cycling performance of low‐cost cathodes are discussed. Also, effective strategies are summarized from the recent progress on long‐cycle‐life and low‐cost cathodes. This review is expected to encourage deeper investigation of long‐lifespan cathodes for SIBs, particularly for potential large‐scale industrialization. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries (SIBs) are considered as a low‐cost complementary or alternative system to prestigious lithium‐ion batteries (LIBs) because of their similar working principle to LIBs, cost‐effectiveness, and sustainable availability of sodium resources, especially in large‐scale energy storage systems (EESs). Among various cathode candidates for SIBs, Na‐based layered transition metal oxides have received extensive attention for their relatively large specific capacity, high operating potential, facile synthesis, and environmental benignity. However, there are a series of fatal issues in terms of poor air stability, unstable cathode/electrolyte interphase, and irreversible phase transition that lead to unsatisfactory battery performance from the perspective of preparation to application, outside to inside of layered oxide cathodes, which severely limit their practical application. This work is meant to review these critical problems associated with layered oxide cathodes to understand their fundamental roots and degradation mechanisms, and to provide a comprehensive summary of mainstream modification strategies including chemical substitution, surface modification, structure modulation, and so forth, concentrating on how to improve air stability, reduce interfacial side reaction, and suppress phase transition for realizing high structural reversibility, fast Na+ kinetics, and superior comprehensive electrochemical performance. The advantages and disadvantages of different strategies are discussed, and insights into future challenges and opportunities for layered oxide cathodes are also presented. [ABSTRACT FROM AUTHOR]

Carbon nanospheres (CNSs) have attracted great interest in energy conversion and storage technologies due to their excellent chemical and thermal stability, high electrical conductivity and controllable size structure characteristics. In order to further improve the energy storage properties, many efforts have been made to design suitable nanocarbon spherical materials to improve electrochemical performance. In this overview, we summarize the recent research progress on CNSs, mainly focusing on the synthesis methods and their application as high-performance electrode materials in rechargeable batteries. As for the synthesis methods, hard template methods, soft template methods, the extension of the Stöber method, hydrothermal carbonization, aerosol-assisted synthesis are described in detail. In addition, the use of CNSs as electrodes in energy storage devices (mainly concentrated on lithium-ion batteries (LIBs)), sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) are also discussed in detail in this article. Finally, some perspectives on the future research and development of CNSs are provided. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries (SIBs) show tremendous potential for large‐scale energy storage systems due to the high abundance of sodium resources and potentially low cost. Among the discovered anode materials for SIBs, metal selenides with large theoretical capacities are considered as a promising candidate. Nevertheless, metal selenide‐based anodes are trapped by poor ionic/electronic conductivity, low initial Coulombic efficiency, and drastic volume changes during the (de)sodiation process. Herein, the differences in sodium‐storage mechanisms of different metal selenides are first analyzed. Subsequently, the specific challenges and corresponding modification strategies (such as nanostructure design, carbon modification, potential window regulation, electrolyte optimization, and constructing heterostructures) for metal selenides as SIB anodes are discussed in detail, and recent advances are also presented. Finally, the potential research directions of metal selenides in SIBs are comprehensively reviewed. It is believed that this review can provide constructive comments on the optimization and large‐scale application of high‐performance metal selenide‐based anode for SIBs. [ABSTRACT FROM AUTHOR]

Room‐temperature sodium–sulfur (RT‐Na/S) batteries are emerging as promising candidates for stationary energy‐storage systems, due to their high energy density, resource abundance, and environmental benignity. A better understanding of RT‐Na/S batteries in the view of the whole battery components is of essential importance for fundamental research and practical applications. In particular, the components other than sulfur cathodes in preventing the migration of polysulfides and accelerating the reaction kinetics have been greatly overlooked. Such a biased research trend is also adverse to the broader applications for RT‐Na/S batteries, which have long been ignored in previous reviews. Herein, approaches to the historical progress toward practical RT‐Na/S batteries through a "teamwork" perspective are comprehensively summarized, and balanced research trends are encouraged to enable practical RT‐Na/S batteries. In the meantime, the persisting issues, promising solutions, and practical applications of advanced sulfur host design, Na metal anode protection, electrolyte optimization, separator modification, and binder engineering are clearly emphasized. Finally, the device‐scale evaluation in practical parameters and advanced characterization tools are thoroughly provided. This review aims to provide the "teamwork" perspective on the whole‐cell design and fundamental guidelines that can shed light on research directions for practical RT‐Na/S batteries. [ABSTRACT FROM AUTHOR]

Sodium metal batteries are recognized as promising candidates for next‐generation energy storage devices, as a result of their high energy density, low redox potential, and cheap material price. Na metal anodes, however, generally exhibit notorious problems, including progressively thickened interfaces with active Na loss and Na metal dendrite growth with safety hazards. Herein, a lightweight aerogel consisting of MgF2 nanocrystals grown on a reduced graphene oxide (RGO) aerogel matrix (MgF2@RGO) is rationally designed as a multifunctional host material for Na metal anodes. The MgF2 nanocrystals can be electrochemically converted in situ into Mg and NaF nanograins during the first Na plating process, in which the Mg works as sodiophilic nucleation seeds for Na plating and NaF plays a key role in suppressing Na dendrite growth. Significantly, the Na metal anodes with the MgF2@RGO aerogel host deliver significantly enhanced Coulombic efficiency and dramatically improved cycling stability for more than 1600 h. The morphology evolution confirms the advantages of the Na metal anode with the MgF2@RGO host, which exhibits dense and flat interfaces. By pairing with the Na3V2(PO4)3 cathode, the Na metal batteries achieve stable cycling and good rate capability, suggesting the potential of the Na/MgF2@RGO anode for practical applications. [ABSTRACT FROM AUTHOR]

The exploration of facile, low‐cost, and universal synthetic strategies for high‐performance aqueous energy storage is extremely urgent. The electrochemical activation tactic is an emerging synthetic technique that can turn inert or weakly active substances into highly active materials for aqueous energy storage via in situ or ex situ electrochemical treatment, which is receiving increasing attention due to its advantages of facile operation, variable control, high efficiency, flexibility, and wide applicability. This review first discusses the definition and general implementing methods of the electrochemical activation tactic, as well as the fundamental activation mechanisms, and then summarizes its applications in various aqueous systems, including rechargeable batteries and electrochemical capacitors with different charge carriers. The remaining challenges, potential solutions, and further perspectives are discussed finally. It is believed that this review will provide a timely summary and new inspiration for cutting‐edge research on advanced aqueous energy storage devices. [ABSTRACT FROM AUTHOR]

Recently, environmental degradation along with the energy crisis has led to an urgent necessity to develop renewable and clean energy storage devices. The sodium ion batteries (SIBs) have become promising candidates in the whole energy storage system, due to its rich and low‐cost sodium resources. To accelerate the commercialization of SIBs, the energy density of SIBs needs to be further improved. Increasing the operating voltage of SIBs is considered to be an effective method, which requires stable and high‐voltage cathode materials. Comparatively, polyanionic sulfate materials (PSMs) with stable skeletons, adjustable structures, operational safety, and the high electronegativity of SO42− are believed to be the most promising high‐energy‐cathodes. In this review, recent progresses on several typical sulfates for SIBs are summarized. What's more, based on their intrinsic characteristics, the structures and kinetic behaviors of PSMs are also discussed. Reported measures to optimize their electrochemical performances and structural stability are summarized and reviewed. The key challenges and corresponding opportunities for PSMs are also discussed. The insights presented in this review may be a guide for designing and developing stable and practical PSMs for room‐temperature SIBs, which is conducive to promoting their industrialization. [ABSTRACT FROM AUTHOR]

Intercalation‐based anode materials can be considered as the most promising anode candidates for large‐scale sodium‐ion batteries (SIBs), owing to their long‐term cycling stability and environmental friendliness, as well as their natural abundance. Nevertheless, their low energy density, low initial coulombic efficiency, and poor cycling lifespan, as well as sluggish sodium diffusion dynamics are still the main issues for the application of intercalation‐based anode materials in SIBs in terms of meeting the benchmark requirements for commercialization. Over the past few years, tremendous efforts have been devoted to improving the performance of SIBs. In this Review, recent progress in the development of intercalation‐based anode materials, including TiO2, Li4Ti5O12, Na2Ti3O7, and NaTi2(PO4)3, is summarized in terms of their sodium storage performance, critical issues, sodiation/desodiation behavior, and effective strategies to enhance their electrochemical performance. Additionally, challenges and perspectives are provided to further understand these intercalation‐based anode materials. [ABSTRACT FROM AUTHOR]

Growing demands on energy storage devices have inspired a tremendous amount of research on rechargeable batteries. Future generations of rechargeable batteries are required to have high energy density, long lifespan, low cost, high safety, low environmental impact, and wide commercial affordability. To achieve these goals, significant efforts are underway to focus on electrolyte chemistry, electrode engineering, and new designs for energy storage systems. Herein, a comprehensive overview of an innovative sodium‐based hybrid metal‐ion battery (HMIBs) for advanced next‐generation energy storage is presented. Recent advances on sodium‐based HMIBs from the development of reformulated or novel materials associated with Na+ ions and other metal ions (such as Li+, K+, Mg2+, Zn2+, etc.), are summarized in this work. Daniell cell and "rocking‐chair" type batteries are covered. Finally, the current challenges and future remedies in terms of the design and fabrication of new electrolytes, cathodes, and anodes for advanced HMIBs are discussed in this report. [ABSTRACT FROM AUTHOR]

Over the past decades, porous carbonaceous and carbon‐incorporated composites have aroused tremendous attention owing to their unique properties such as high surface area, excellent accessibility to active sites, tunable morphologies and structures, and superior mass transport and diffusion. They have been widely investigated and applied in various fields, such as energy storage, absorption, water filtration, drug delivery, catalysis, and sensing. In the energy storage area, rechargeable sodium‐ion batteries (SIBs) have attracted tremendous attention as the next‐generation power plants for large‐scale energy storage systems (EESs). However, their low energy density and power density, as well as their poor cyclability, are still the main challenges for SIBs, especially for the anode, which acts as a bottleneck. With the incorporation of appropriate porous carbonaceous materials, the disadvantages of large volume shrinkage and low electron conductivity of alloying‐ and conversion‐based anode materials have been significantly alleviated. This review points out and summarizes the most recent developments in synthesis strategies and morphology control of porous carbonaceous materials and the corresponding carbonaceous‐material‐incorporated high performance anodes for SIBs. Furthermore, the remaining challenges associated with these composites and effective routes to enhance their performance are discussed. [ABSTRACT FROM AUTHOR]

High‐quality anodes are very important for the future generations of rechargeable sodium‐ion batteries (SIBs). Metal sulfides (MSs) as a promising anode have attract tremendous attentions and shown impressive results in terms of versatile material species, low‐cost raw materials, and excellent electrochemical performance. In particular, the unique 2D few‐layer structure of MSs provides a new view for overcoming some challenges appeared on anodic electrodes, such as volume change, structure collapse, high‐rate capability, and confinement of phase‐variation of MSs. Here, we review some of the recent scientific advances in 2D MSs, including the synthetic strategies, electronic structure, and electro‐chemical performance on SIBs. [ABSTRACT FROM AUTHOR]

Abstract: Since their successful commercialization in 1990s, lithium‐ion batteries (LIBs) have been widely applied in portable digital products. The energy density and power density of LIBs are inadequate, however, to satisfy the continuous growth in demand. Considering the cost distribution in battery system, it is essential to explore cathode/anode materials with excellent rate capability and long cycle life. Nanometer‐sized electrode materials could quickly take up and store numerous Li+ ions, afforded by short diffusion channels and large surface area. Unfortunately, low thermodynamic stability of nanoparticles results in electrochemical agglomeration and raises the risk of side reactions on electrolyte. Thus, micro/nano and hetero/hierarchical structures, characterized by ordered assembly of different sizes, phases, and/or pores, have been developed, which enable us to effectively improve the utilization, reaction kinetics, and structural stability of electrode materials. This review summarizes the recent efforts on electrode materials with hierarchical structures, and discusses the effects of hierarchical structures on electrochemical performance in detail. Multidimensional self‐assembled structures can achieve integration of the advantages of materials with different sizes. Core/yolk–shell structures provide synergistic effects between the shell and the core/yolk. Porous structures with macro‐, meso‐, and micropores can accommodate volume expansion and facilitate electrolyte infiltration. [ABSTRACT FROM AUTHOR]

Abstract: Sodium‐ion batteries (SIBs) have been considered as the most promising candidate for large‐scale energy storage system owing to the economic efficiency resulting from abundant sodium resources, superior safety, and similar chemical properties to the commercial lithium‐ion battery. Despite the long period of academic research, how to realize sodium‐ion battery commercialization for market applications is still a great challenge. Thus, from the perspective of future practical application, this review will identify the factors that are restricting commercialization, and evaluate the existing active materials and sodium‐ion‐based full‐cell system. The design and development trends that are needed for SIBs to meet the requirements of practical applications in large‐scale energy storage will also be discussed in detail. [ABSTRACT FROM AUTHOR]

Rechargeable Mg-air batteries are a promising alternative to Li-air cells owing to the safety, low price originating from the abundant resource on the earth, and high theoretical volumetric density (3832 A h L−1 for Mg anode vs 2062 A h L−1 for Li). Only a few works are related to the highly reversible Mg-air batteries. The fundamental scientific difficulties hindering the rapid development of secondary Mg-air cells are attributed to the poor thermodynamics and kinetics properties mainly owing to the MgO or MgO2 insulating film as the initial discharge product on air-breathing cathode, contributing to the increase of a large overpotential and a high polarization. Very recently, remarkable progress on rechargeable Mg-air batteries is trying to overcome the major limitations in organic electrolytes via the combination of the first-principle calculation and experimental study. Therefore, this progress report highlights a comprehensive and concise survey of the major progress in the history of secondary Mg-air batteries, and the detailed illustrations of corresponding reaction mechanisms. The overview is devoted to open up a new area for manipulating the nanostructures to control the ideal reaction pathway in novel cell configuration and to fully understand the future Mg-air battery with improved energy density and cycling ability. [ABSTRACT FROM AUTHOR]

Sodium-ion energy storage, including sodium-ion batteries (NIBs) and electrochemical capacitive storage (NICs), is considered as a promising alternative to lithium-ion energy storage. It is an intriguing prospect, especially for large-scale applications, owing to its low cost and abundance. MoS2 sodiation/desodiation with Na ions is based on the conversion reaction, which is not only able to deliver higher capacity than the intercalation reaction, but can also be applied in capacitive storage owing to its typically sloping charge/discharge curves. Here, NIBs and NICs based on a graphene composite (MoS2/G) were constructed. The enlarged d-spacing, a contribution of the graphene matrix, and the unique properties of the MoS2/G substantially optimize Na storage behavior, by accommodating large volume changes and facilitating fast ion diffusion. MoS2/G exhibits a stable capacity of approximately 350 mAh g−1 over 200 cycles at 0.25 C in half cells, and delivers a capacitance of 50 F g−1 over 2000 cycles at 1.5 C in pseudocapacitors with a wide voltage window of 0.1-2.5 V. [ABSTRACT FROM AUTHOR]

Abstract: A hybrid electrolyte energy storage system combining the features of supercapacitors and lithium batteries has been constructed. It consists of MnO2 nanoflakes in 1M Li2SO4 aqueous electrolyte as the cathode and lithium foil in ionic liquid (1M lithium bis(trifluoromethanesulfonyl)imide (LiNTf2) in N-methyl-N-propyl pyrrolidinium bis(trifluoromethanesulfonyl)imide ([C3mpyr][NTf2])) electrolyte as the anode, separated by a lithium super ionic conductor glass ceramic film (LiSICON). This system shows the advantages of both a supercapacitor (long cycle life) and a lithium battery (high energy), as well as low cost and improved safety due to the combination of ionic liquid and ceramic solid state electrolyte in lithium side, which can reduce the formation and prevent the penetration of lithium dendrites. The specific energy for the cathode materials in the hybrid electrolyte system is 170Whkg−1 with more than 85% retention up to 2400cycles. This system is a great candidate for stationary batteries storing solar and wind energy. [Copyright &y& Elsevier]

Abstract: Sodium ion battery is a promising electrical energy storage system for sustainable energy storage applications due to the abundance of sodium resources and their low cost. In this communication, the electrochemical properties of sodium ion storage in reduced graphene oxide (RGO) were studied in an electrolyte consisting of 1M NaClO4 in propylene carbonate (PC). The experimental results show that the RGO anode allowed significant sodium ion insertion, leading to higher capacity at high current density compared to the previously reported results for carbon materials. This is due to the fact that RGO possesses higher electrical conductivity and is a more active host, with large interlayer distances and a disordered structure, enabling it to store a higher amount of Na ions. RGO anode exhibits high capacity combined with long-term cycling stability at high current densities, leading to reversible capacity as high as 174.3mAhg−1 at 0.2C (40mAg−1), and even 93.3mAhg−1 at 1C (200mAg−1) after 250 cycles. Furthermore, RGO could yield a high capacity of 141mAhg−1 at 0.2C (40mAg−1) over 1000 cycles. [Copyright &y& Elsevier]

Polysulfide dissolution and slow electrochemical kinetics of conversion reactions lead to low utilization of sulfur cathodes that inhibits further development of room-temperature sodium-sulfur batteries. Here we report a multifunctional sulfur host, NiS2 nanocrystals implanted in nitrogen-doped porous carbon nanotubes, which is rationally designed to achieve high polysulfide immobilization and conversion. Attributable to the synergetic effect of physical confinement and chemical bonding, the high electronic conductivity of the matrix, closed porous structure, and polarized additives of the multifunctional sulfur host effectively immobilize polysulfides. Significantly, the electrocatalytic behaviors of the Lewis base matrix and the NiS2 component are clearly evidenced by operando synchrotron X-ray diffraction and density functional theory with strong adsorption of polysulfides and high conversion of soluble polysulfides into insoluble Na2S2/Na2S. Thus, the as-obtained sulfur cathodes exhibit excellent performance in room-temperature Na/S batteries. Room temperature rechargeable sodium sulfur batteries are promising for next-generation energy storage systems, but their development is limited by polysulfide dissolution and slow kinetics. Here the authors report a cathode that serves as a multifunctional sulfur host and imparts enhanced performance. [ABSTRACT FROM AUTHOR]

Recently, room‐temperature stationary sodium‐ion batteries (SIBs) have received extensive investigations for large‐scale energy storage systems (EESs) and smart grids due to the huge natural abundance and low cost of sodium. The SIBs share a similar "rocking‐chair" sodium storage mechanism with lithium‐ion batteries; thus, selecting appropriate electrodes with a low cost, satisfactory electrochemical performance, and high reliability is the key point for the development for SIBs. On the other hand, the carefully chosen elements in the electrodes also largely determine the cost of SIBs. Therefore, earth‐abundant‐metal‐based compounds are ideal candidates for reducing the cost of electrodes. Among all the high‐abundance and low‐cost metal elements, cathodes containing iron and/or manganese are the most representative ones that have attracted numerous studies up till now. Herein, recent advances on both iron‐ and manganese‐based cathodes of various types, such as polyanionic, layered oxide, MXene, and spinel, are highlighted. The structure–function property for the iron‐ and manganese‐based compounds is summarized and analyzed in detail. With the participation of iron and manganese in sodium‐based cathode materials, real applications of room‐temperature SIBs in large‐scale EESs will be greatly promoted and accelerated in the near future. State‐of‐the‐art high‐abundance and low‐cost metal‐based cathode materials for sodium‐ion batteries are comprehensively summarized and analyzed, providing a step toward the real‐life, commercial application of sodium‐ion batteries. Constructive suggestions and guidance are provided and future prospects regarding this promising field are discussed. [ABSTRACT FROM AUTHOR]

A novel anode material for sodium ion batteries - nanosized CoP particles - was synthesized by a facile and productive ball-milling method. The CoP was tested as an anode candidate for sodium ion batteries. It delivered a high initial specific capacity of 770 mAh g −1 , and excellent rate capability, demonstrating that CoP is a promising anode candidate for sodium ion storage. Ex-situ X-ray photoelectron spectroscopy and scanning transmission electron microscopy were carried out to investigate the sodium storage mechanism of CoP. [ABSTRACT FROM AUTHOR]

Highlights: [•] A model of TiO2 nanotube arrays growing on Ti mesh was proposed. [•] The TiO2/Ti mesh was used for the anode without current collector or binder required. [•] The capacity of the TiO2/Ti-600min mesh electrode is 1745.5μAhcm−2 over 100 cycles. [•] The TiO2/Ti mesh electrode still maintains its 3D nanostructure after 100 cycles. [Copyright &y& Elsevier]

Despite the high theoretical capacity of the sodium–sulfur battery, its application is seriously restrained by the challenges due to its low sulfur electroactivity and accelerated shuttle effect, which lead to low accessible capacity and fast decay. Herein, an elaborate carbon framework, interconnected mesoporous hollow carbon nanospheres, is reported as an effective sulfur host to achieve excellent electrochemical performance. Based onin situsynchrotron X-ray diffraction, the mechanism of the room temperature Na/S battery is proposed to be reversible reactions between S8and Na2S4, corresponding to a theoretical capacity of 418 mAh g–1. The cell is capable of achieving high capacity retention of ∼88.8% over 200 cycles, and superior rate capability with reversible capacity of ∼390 and 127 mAh g–1at 0.1 and 5 A g–1, respectively. [ABSTRACT FROM AUTHOR]

Electrode materials with a three-dimensional (3D) layered framework and excellent electrochemical stability can provide a new avenue for enhancing the overall performance of promising sodium ion batteries. Here, we show that layered monoclinic (m ) - ZnV 2 O 6 nanobelts with high chemical activity for Na-ion energy storage have been effectively fabricated via a rapid microwave irradiation method over the reaction time of 8 h, in which the fabricating efficiency is 24.5 times greater in comparison with the traditional hydrothermal method. The morphology and phase evolutions were verified by means of X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. This study also proposes the “topotactic transformation−Ostwald ripening” mechanism in layered m -ZnV 2 O 6 nanobelts, from one-dimensional (1D) m -Zn 2 V 2 O 7 with tunnel structure to a 3D m -ZnV 2 O 6 layered structure. In particular, the m -ZnV 2 O 6 nanobelt anode exhibited a high discharge capacity of 480.5 mAh g −1 at a current density of 10 mA g −1 , and maintained the considerable discharge capacity of 246.9 mAh g −1 at the 100 th cycle. The very preliminary results are promising and confirming that layered metallic vanadium can give a new insight into designing novel anode materials for high-efficiency energy storage in sodium ion batteries. [ABSTRACT FROM AUTHOR]