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Abstract: Sodium‐ion technology has the potential to become the next generation of low cost and environmentally friendly electrochemical energy storage system for grid‐level applications. The low cost and abundant raw materials employed in sodium cells have driven the recent increasing interest in sodium‐ion batteries (SIBs), which appear especially appealing, since manufacturers can use the already existing production technology of lithium‐ion batteries. However, SIBs are still an early stage technology, which requires several issues affecting cell performance to be addressed. Despite the accelerated development of cathode materials, anode materials still require further investigation and optimization to reach high energy density performance. In the pursuit of high capacity anode materials, several alloying‐, conversion‐, and combined conversion–alloying‐based electrodes have been investigated. This review offers a comprehensive overview on the recent progresses toward the realization of “beyond‐insertion” anode materials. The role of nanostructuration with the associated advantages and disadvantages is presented for each class of compounds, combined with the main strategies adopted to improve the electrochemical behavior. Finally, an overview of the challenges and perspectives associated with the development of the next generation of anode materials is presented with a particular focus on the role of the electrolyte solutions and solid/electrolyte interphase. [ABSTRACT FROM AUTHOR]

Advanced reactors are often claimed to be passively safe against unprotected upset events. In common practice, these events are not considered in the context of the plant control system, i.e., the reactor is subjected to classes of unprotected upset events while the normally programmed response of the control system is assumed not to be present. However, this approach constitutes an oversimplification since, depending on the upset involving the control system, an actuator does not necessarily go in the same direction as needed for safety. In this work, dynamic simulations are performed to assess the degree to which the inherent self-regulating plant response is safe from active control system override. The simulations are meant to characterize the resilience of the plant to unprotected initiators. The initiators were represented and modeled as an actuator going to a hard limit. Consideration of failure is further limited to individual controllers as there is no cross-connect of signals between these controllers. The potential for passive safety override by the control system is then relegated to the single-input single-output controllers. The results show that when the plant control system is designed by taking into account and quantifying the impact of the plant control system on accidental scenarios there is very limited opportunity for the preprogrammed response of the control system to override passive safety protection in the event of an unprotected initiator. [ABSTRACT FROM PUBLISHER]

The interaction of the active control system with passive safety behavior is investigated for sodium-cooled fast reactors. A claim often made of advanced reactors is that they are passively safe against unprotected upset events. In practice, such upset events are not analyzed in the context of the plant control system, but rather the analyses are performed without considering the normally programmed response of the control system (open-loop approach). This represents an oversimplification of the safety case. The issue of passive safety override arises since the control system commands actuators whose motions have safety consequences. Depending on the upset involving the control system (operator error, active control system failure, or inadvertent control system override), an actuator does not necessarily go in the same direction as needed for safety. So neglecting to account for control system action during an unprotected upset is nonconservative from a safety standpoint. It is important then, during the design of the plant, to consider the potential for the control system to work against the inherent and safe regulating effects of purposefully engineered temperature feedbacks. [ABSTRACT FROM PUBLISHER]

Computational screening is a powerful tool used to identify solvents for application in EDLC electrolytes. One of the solvents recently introduced by this method, 3-cyanopropionic acid methyl ester, is herein successfully tested as electrolyte in combination with the salt 1-butyl-1-methylpyrrolidinium tetrafluoroborate ([Pyr 14 ][BF 4 ]). High salt concentrations, as well as operative voltages of 3.0 V are possible with this combination, proving that this new solvent is indeed a promising new candidate for a new class of electrolyte materials for EDLCs. [ABSTRACT FROM AUTHOR]

Bilayered V2O5· nH2O prepared by sol-gel synthesis is generally assumed amorphous due to lack of long-range structural order. However, at the nanoscale, a well-organized repetition of bilayers is found and thus V2O5· nH2O can be considered a nanostructured material. Synthesis route affects the morphological and structural characteristics of V2O5· nH2O and, depending on the drying method used, xerogel and aerogel are obtained. The reduced structural order, the large interlayer space and the short diffusion length that this class of material offer are the key factors that allow V2O5· nH2O to reversibly host cations that are different in charge and dimensions. These properties make bilayered V2O5· nH2O materials almost unique for the wide range of applicability in metal batteries. Herein, a panoramic of the most common V2O5· nH2O synthesis methods and the peculiar characteristics of this material is given. A survey of the most important findings on the use of bilayered V2O5· nH2O for metal batteries is reported focusing on Li-, Na- and Mg-batteries. The increased number of publications recently divulgated confirms the renewed interest on V2O5· nH2O for energy storage and thus an updated rationalization of the findings can be helpful to guide further technological development and research activity in the field. [ABSTRACT FROM AUTHOR]

We study the liquid mixture of sodium bis(trifluoromethanesulfonyl)imide in N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr 14 TFSI-NaTFSI) for application in sodium-ion batteries. The ionic liquid-based electrolyte is characterized in terms of electrochemical and thermal properties. Ionic conductivity and electrochemical stability windows are evaluated through electrochemical impedance spectroscopy (EIS) measurements and voltammetry tests, respectively. The thermal stability is evaluated by differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). Moreover, the suitability of the IL-electrolyte is preliminary verified in half and in full-cells at room temperature, using P2-Na 0.6 Ni 0.22 Fe 0.11 Mn 0.66 O 2 layered oxide cathode and nanostructured Sb–C composite anode. The cell shows promising characteristics with a working voltage of about 2.7 V and a delivered capacity of about 100 mAh g −1 . Despite requiring further optimization in terms of cycle life and energy density, the data here reported suggest the suitability of the ionic liquid electrolyte for application in sodium-ion battery. [ABSTRACT FROM AUTHOR]

Potatoes starch (PS), a natural polymer obtainable from non-edible sources, is for the first time evaluated as alternative water-processable binder for Electrochemical Double-Layer Capacitor (EDLC) electrodes. Morphological and electrochemical properties of activated carbon (AC)-based electrodes are investigated and compared to those achieved with the state-of-the-art aqueous binder (CMC, i.e. Na-carboxymethyl cellulose). The obtained results suggest substantial benefits of PS, in particular regarding the electrode fabrication process. As a matter of fact, owing to its amylopectin content (moderately branched polysaccharide), PS displays only minimal shrinkage upon drying, resulting on rather homogeneous electrodes not presenting the dramatic surface cracking observed with CMC. Furthermore, owing to the smaller volume of water required for the processing, much higher active material loading per area unit can be achieved. This is reflected on improvements of up to 60% in terms of areal capacitance. [ABSTRACT FROM AUTHOR]

Simulation results are presented for a design strategy that seeks to achieve inherent control and passive safety for liquid-metal advanced small modular reactors. The approach places an increased reliance on passive feedbacks to regulate plant operation. A reference liquid-metal reactor design is defined to serve as a baseline against which innovative design concepts can be compared with respect to operational performance. The definition assigns values to key plant parameters related to materials type, component data, system configuration (loop versus pool type), fuel cycle (burner versus breakeven versus breeder), and balance of plant. The reference design represents the state of the art of conventional fast reactor technology in terms of economics of electricity production, use of active control systems, and standard operation (e.g., refueling every 2 to 3 years). Innovative design features and associated control strategies are then investigated for reducing the size of upset imitators and for improving also the safety of the inherent response to the initiator. Initiators include failures of active systems and operator errors. At the same time the ability of the modified plant to meet normal grid demands subject to constraints on temperature rates of change is assessed. Results presented indicate that operational performance can be maintained while active system initiator size is reduced resulting in improved safety. Essentially, the innovations introduce inherent feedback mechanisms that serve to reduce the magnitude of the control action of the active control systems. [ABSTRACT FROM AUTHOR]

The recent interest in the Small Modular Reactor (SMR) for its potential increased economic competitiveness has focused attention in part on reducing operational costs to offset those plant costs that do not benefit from the economies of scale of large traditional units. Plant operation and maintenance economics are significantly driven by plant availability, which can be enhanced by means of innovative control strategies by avoiding unnecessary plant or unit trips. In this context, an effective strategy for achieving fast runback of a sodium-cooled SMR has been developed. In this work, after having defined and modeled a suitable control strategy by adopting the Petri nets formalism, a Model-based Predictive Control regulator has been developed in order to reduce as promptly as possible the power level, without scramming the reactor (fast runback) and possibly limiting the control rod contribution. Such flexibility could lead to significant savings in the operational costs of the reactor while also improving the system availability. The proposed procedure has been characterized by simulating the operational transients on both an oxide-fueled reactor and on a metal-fueled reactor, comparing the responses of the two different configurations and the respectively needed control rod contribution. [ABSTRACT FROM AUTHOR]

Interfacial dynamics within chemical systems such as electron and ion transport processes have relevance in the rational optimization of electrochemical energy storage materials and devices. Evolving the understanding of fundamental electrochemistry at interfaces would also help in the understanding of relevant phenomena in biological, microbial, pharmaceutical, electronic, and photonic systems. In lithium‐ion batteries, the electrochemical instability of the electrolyte and its ensuing reactive decomposition proceeds at the anode surface within the Helmholtz double layer resulting in a buildup of the reductive products, forming the solid electrolyte interphase (SEI). This review summarizes relevant aspects of the SEI including formation, composition, dynamic structure, and reaction mechanisms, focusing primarily on the graphite anode with insights into the lithium metal anode. Furthermore, the influence of the electrolyte and electrode materials on SEI structure and properties is discussed. An update is also presented on state‐of‐the‐art approaches to quantitatively characterize the structure and changing properties of the SEI. Lastly, a framework evaluating the standing problems and future research directions including feasible computational, machine learning, and experimental approaches are outlined. [ABSTRACT FROM AUTHOR]

The article offers information related to the development of lithium-ion batteries (LIBs) focusing on the challenges in its development. It mentions several types LIBs that were developed using various materials including LIB electrodes created through anodes, LIB electrodes developed using cathodes, and LIB electrolytes created using organic carbonate mixed solvents such as ethylene carbonate-dimethyl carbonate (EC:DMC).

This review is an attempt to report the latest development in lithium–sulfur batteries, namely the storage system that, due to its potential energy content, is presently attracting considerable attention both for automotive and stationary storage applications. We show here that consistent progress has been achieved, to the point that this battery is now considered to be near to industrial production. However, the performance of present lithium–sulfur batteries is still far from meeting their real energy density potentiality. Thus, the considerable breakthroughs so far achieved are outlined in this review as the basis for additional R&D, with related important results, which are expected to occur in the next few years. [ABSTRACT FROM AUTHOR]

Here we provide a detailed X-rayphotoelectron spectroscopy (XPS)study of the electrode/electrolyte interface of a graphite anode fromcommercial NMC/graphite cells by intense sputter depth profiling usinga polyatomic ion gun. The uniqueness of this method lies in the approachusing 13-step sputter depth profiling (SDP) to obtain a detailed modelof the film structure, which forms at the electrode/electrolyte interfaceoften noted as the solid electrolyte interphase (SEI). In additionto the 13-step SDP, several reference experiments of the untreatedanode before formation with and without electrolyte were carried outto support the interpretation. Within this work, it is shown thatthrough charging effects during X-ray beam exposure chemical componentscannot be determined by the binding energy (BE) values only, and inaddition, that quantification by sputter rates is complicated forcomposite electrodes. A rough estimation of the SEI thickness wascarried out by using the LiF and graphite signals as internal references. [ABSTRACT FROM AUTHOR]

The effect of nano-sized silica and γ-LiAlO2 on the electrochemical and interfacial properties of P(EO)20LiN(SO2CF2CF3)2–10 wt.% filler polymer electrolytes has been studied using linear sweep voltammetry, ac impedance and galvanostatic stripping/deposition on symmetric non-blocking cells. Non-symmetric cells were used to investigate the electrochemical stability window. The limiting current density of the P(EO)20LiBETI polymer electrolytes at 90 °C was found to decrease with the addition of nano-sized filler. The presence of silica caused higher interface resistance during storage in open circuit at 90 °C. For the galvanostatic Li stripping/deposition at 0.2 mA/cm2 at 90 °C, the silica containing electrolyte showed the highest initial overvoltage due to the high interface resistance. These results suggest that the presence of nano-size silica in solvent-free P(EO)20LiBETI polymer electrolytes results in no substantial improvement on the electrochemical and interfacial properties of the electrolytes at 90 °C. [Copyright &y& Elsevier]

Recent reports have indicated higher ionic conductivities in crystalline polymer electrolytes consisting of isostructural P(EO)6:LiX (X=PF6, AsF6, SbF6) phases relative to the analogous amorphous materials. These reports challenge the conventional wisdom in polymer electrolyte research that amorphous electrolytes are much more conductive than crystalline ones. The higher conductivity in the crystalline materials was attributed to the structures in which Li+ cations are located within PEO cylinders uncoordinated by the anions. The conductivity and crystallinity of P(EO)n–LiClO4 (EO/Li=6 and 10) electrolytes have been examined here. In contrast to the recent reports, much lower conductivities are found for the isostructural P(EO)6:LiClO4 crystalline electrolyte relative to the same fully amorphous electrolyte. [Copyright &y& Elsevier]

Gel polymer electrolytes (GPEs) were prepared by dipping a polyethylene oxide (PEO)-based solid polymer electrolyte in lithium triflate/propylene carbonate (PC) liquid electrolyte solutions. The quantity of the liquid electrolyte gelled in the polymer was monitored as a function of dipping time in several liquid electrolytic solutions characterized by a different salt concentration. The GPE conductivity was measured as a function of the salt concentration and the liquid fraction content. The Li/GPE interface properties were evaluated by monitoring the charge transfer resistance at open circuit voltage and the lithium cycling efficiency under dynamic conditions. Chronopotentiometry measurements were used to study the variations of the lithium ion concentration in the electrolyte near the electrode surface. The transition time and the lithium diffusion coefficient were calculated as a function of the salt concentration of the liquid electrolyte used to swell the polymer electrolyte. The GPE electrochemical stability was measured by slow scan voltammetry sweep. Battery cells were assembled by sandwiching a GPE between a lithium disk and a gelled PEO-based composite cathode. The battery performance was evaluated at various discharge rates, while the rechargeability was tested under galvanostatic conditions at the C/10 rate. [Copyright &y& Elsevier]

Reports on the use of polarized x-ray absorption spectroscopy to study the short-range structure of deposited films of V2O5 xerogel. Presence in the material of a layer of VO5 units with the V-O apical bond perpendicular to the basal (xy) plane; Confirmation of the existence of a vanadium-vanadium interaction between two different V2O5 layers and an oxygen bridge between them.

Rechargeable aqueous zinc–metal batteries (AZBs) are a promising complimentary technology to the existing lithium‐ion batteries and the re‐emerging lithium–metal batteries to satisfy the increasing demands on energy storage. Despite considerable progress achieved in the past years, the fundamental understanding of the solid‐electrolyte interphase (SEI) formation and how its composition influences the SEI properties are limited. This review highlights the functionalities of anion‐tuned SEI on the reversibility of zinc–metal anode, with a specific emphasis on new structural insights obtained through advanced characterizations and computational techniques. Recent efforts in terms of key variables that govern the interfacial behaviors to improve the long‐term stability of zinc anode, i.e., Coulombic efficiency, plating morphology, dendrite formation, and side‐reactions, are comprehensively reviewed. Lastly, the remaining challenges and future perspectives are presented, providing insights into the rational design of practical high‐performance AZBs. [ABSTRACT FROM AUTHOR]

Lithium metal batteries (LMBs) have the potential to be the next‐generation rechargeable batteries due to the high theoretical specific capacity and the lowest redox potential of lithium metal. However, the practical application of LMBs is hindered by challenges such as the uncontrolled growth of lithium dendrites, unstable solid electrolyte interphase (SEI), and excessive volume change of Li metal. To solve these issues, the design of high‐performance lithium metal anodes (LMAs) with various 3D structures is critical. Targeting at realizing the "bottom–up" Li deposition to fully utilize the 3D architecture, in recent years, strategies such as gradient host materials construction, magnetic field modulation, SEI component design, and so on have attracted intensive attention. This review begins with a fundamental discussion of the Li nucleation and deposition mechanism. The recent advances in the aspects of construction strategies and modification methods that enable the "bottom–up" Li deposition within advanced 3D host materials, with a particular emphasize on their design principles are comprehensively overviewed. Finally, future challenges and perspectives on the design of advanced hosts toward practical LMAs are proposed. [ABSTRACT FROM AUTHOR]

Aqueous ammonium‐ion batteries (AAIBs) are considered as one of the most promising technologies for large scale energy storage applications, due to their intrinsic safety, environmental friendliness and low cost. Nevertheless, the practical application of AAIBs is impeded by hydrogen evolution reaction (HER) occurring in diluted aqueous electrolyte. Highly concentrated electrolytes can improve electrochemical stability but lead to higher costs and increased hydrolysis of NH4+. In this work ethylene glycol (EG) is proposed as co‐solvent, which can act as H‐bond modulating agent, to increase the stability of AAIBs with diluted electrolytes. The perturbation of water H‐bond network regulated by EG is proved by spectroscopic methods, while the suppressed HER is confirmed by differential electrochemical mass spectrometry (DEMS) results. As a result, full cells with 3,4,9,10‐perylenebis(dicarboximide) (PTCDI) anode and FeFe(CN)6 (FeHCF) cathode and EG‐added electrolyte exhibit stable cycling performance with capacity retention of 77% after 1950 cycles. [ABSTRACT FROM AUTHOR]

The EU's energy transition necessitates availability of green energy carriers with high volumetric energy densities for long‐term energy storage (ES) needs. A fully decarbonized scenario considering renewable energy availability is analyzed underpinning the need for such carriers. Considering the shortcomings of Power‐to‐X technologies in terms of efficiency and low volumetric density, Aluminum (Al) is identified as a potential alternative showing significantly high volumetric energy densities (23.5 kWh L−1). In this paper, an Al‐based long‐term ES concept is investigated, taking advantage of the inherent recycling of the active species (i.e., Al2O3 to Al) coupling decarbonized Hall–Héroult process with an Al‐steam oxidation for simultaneous hydrogen (H2) and heat generation. This work demonstrates an innovative lab‐scale fine Al powder‐steam oxidation process at ≈900 °C without use of catalysts or additives, exploiting alumina as inert material. Conducted SEM‐EDX analysis on oxidized Al provides supporting evidence in favor of employed oxidation pathway, hindering tendency of aluminum oxide (Al2O3) clumping and enabling direct use of oxides in the smelting process for fully recyclability. Moreover, outcomes of XRD analyses are presented to validate the measured total H2 yields. [ABSTRACT FROM AUTHOR]

Aqueous ammonium‐ion (NH4+) batteries (AAIB) are a recently emerging technology that utilize the abundant electrode resources and the fast diffusion kinetics of NH4+ to deliver an excellent rate performance at a low cost. Although significant progress has been made on AAIBs, the technology is still limited by various challenges. In this Minireview, the most recent advances are comprehensively summarized and discussed, including cathode and anode materials as well as the electrolytes. Finally, a perspective on possible solutions for the current limitations of AAIBs is provided. [ABSTRACT FROM AUTHOR]

Aqueous ammonium‐ion (NH4+) batteries (AAIB) are a recently emerging technology that utilize the abundant electrode resources and the fast diffusion kinetics of NH4+ to deliver an excellent rate performance at a low cost. Although significant progress has been made on AAIBs, the technology is still limited by various challenges. In this Minireview, the most recent advances are comprehensively summarized and discussed, including cathode and anode materials as well as the electrolytes. Finally, a perspective on possible solutions for the current limitations of AAIBs is provided. [ABSTRACT FROM AUTHOR]

Solid-state batteries are considered the next big step towards the realization of intrinsically safer high-energy lithium batteries for the steadily increasing implementation of this technology in electronic devices and particularly, electric vehicles. However, so far only electrolytes based on poly(ethylene oxide) have been successfully commercialized despite their limited stability towards oxidation and low ionic conductivity at room temperature. Block copolymer (BCP) electrolytes are believed to provide significant advantages thanks to their tailorable properties. Thus, research activities in this field have been continuously expanding in recent years with great progress to enhance their performance and deepen the understanding towards the interplay between their chemistry, structure, electrochemical properties, and charge transport mechanism. Herein, we review this progress with a specific focus on the block-copolymer nanostructure and ionic conductivity, the latest works, as well as the early studies that are fr"equently overlooked by researchers newly entering this field. Moreover, we discuss the impact of adding a lithium salt in comparison to single-ion conducting BCP electrolytes along with the encouraging features of these materials and the remaining challenges that are yet to be solved. [ABSTRACT FROM AUTHOR]

Aluminum−sulfur (Al−S) batteries are promising energy storage devices due to their high theoretical capacity, low cost, and high safety. However, the high viscosity and inferior ion transport of conventionally used ionic liquid electrolytes (ILEs) limit the kinetics of Al−S batteries, especially at sub‐zero temperatures. Herein, locally concentrated ionic liquid electrolytes (LCILE) formed via diluting the ILEs with non‐solvating 1,2‐difluorobenzene (dFBn) co‐solvent are proposed for wide‐temperature‐range Al−S batteries. The addition of dFBn effectively promotes the fluidity and ionic conductivity without affecting the AlCl4−/Al2Cl7− equilibrium, which preserves the reversible stripping/plating of aluminum and further promotes the overall kinetics of Al−S batteries. As a result, Al−S cells employing the LCILE exhibit higher specific capacity, better cyclability, and lower polarization with respect to the neat ILE in a wide temperature range from −20 to 40 °C. For instance, Al−S batteries employing the LCILE sustain a remarkable capacity of 507 mAh g−1 after 300 cycles at 20 °C, while only 229 mAh g−1 is delivered with the dFBn‐free electrolyte under the same condition. This work demonstrates the favorable use of LCILEs for wide‐temperature Al−S batteries. [ABSTRACT FROM AUTHOR]

Aluminum−sulfur (Al−S) batteries are promising energy storage devices due to their high theoretical capacity, low cost, and high safety. However, the high viscosity and inferior ion transport of conventionally used ionic liquid electrolytes (ILEs) limit the kinetics of Al−S batteries, especially at sub‐zero temperatures. Herein, locally concentrated ionic liquid electrolytes (LCILE) formed via diluting the ILEs with non‐solvating 1,2‐difluorobenzene (dFBn) co‐solvent are proposed for wide‐temperature‐range Al−S batteries. The addition of dFBn effectively promotes the fluidity and ionic conductivity without affecting the AlCl4−/Al2Cl7− equilibrium, which preserves the reversible stripping/plating of aluminum and further promotes the overall kinetics of Al−S batteries. As a result, Al−S cells employing the LCILE exhibit higher specific capacity, better cyclability, and lower polarization with respect to the neat ILE in a wide temperature range from −20 to 40 °C. For instance, Al−S batteries employing the LCILE sustain a remarkable capacity of 507 mAh g−1 after 300 cycles at 20 °C, while only 229 mAh g−1 is delivered with the dFBn‐free electrolyte under the same condition. This work demonstrates the favorable use of LCILEs for wide‐temperature Al−S batteries. [ABSTRACT FROM AUTHOR]

Li+-conducting polyethylene oxide-based membranes incorporating N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide are used as electrolyte separators for all-solid-state lithium polymer batteries operating at medium-high temperatures. The incorporation of the ionic liquid remarkably improves the thermal, ion-transport and interfacial properties of the polymer electrolyte, which, in combination with the wide electrochemical stability even at medium-high temperatures, allows high current rates without any appreciable lithium anode degradation. Battery tests carried out at 80 °C have shown excellent cycling performance and capacity retention, even at high rates, which are never tackled by ionic liquid-free polymer electrolytes. No dendrite growth onto the lithium metal anode was observed. [ABSTRACT FROM AUTHOR]

The widespread adaptation of lithium-ion batteries for consumer products, electrified vehicles and grid storage demands further enhancement in energy density, cycle life, and safety, all of which rely on the structural and physicochemical characteristics of cell components. The separator membrane is a key component in an electrochemical cell that is sandwiched between the positive and negative electrodes to prevent physical contact while permitting ionic conduction through the electrolyte. Though it is an inactive component in a cell, the separator has a profound impact on the ionic transport, performance, cell life, and safety of the batteries. Today there are numerous types of separators in use or being considered, including polyolefin separators, modified polyolefin separators, nonwoven separators, and ceramic composite separators. This review summarizes the state of practice and latest advancements in different classes of separator membranes, reviews the advantages and pitfalls of current separator technology, and outlines challenges in the development of advanced separators for future battery applications. The overview of the separator membranes discussed in the review. [Display omitted] • Discusses how separators function while preventing short circuits between electrodes. • Discusses the major classes of separators including polyolefin, nonwoven, and ceramic separators. • Presents the advantages and disadvantages of the various types of separators. • Discusses additives and fire retardants in separators [ABSTRACT FROM AUTHOR]

Cobalt, nickel, manganese and zinc vanadates were synthesized by a hydrometallurgical two-phase method. The extraction of vanadium (V) ions from alkaline solution using Aliquat® 336 was followed by the production of metal vanadates through precipitation stripping. Precipitation stripping was carried out using solutions of the corresponding metal ions (Ni (II), Co (II), Mn (II) and Zn (II), 0.05 mol/L in 4 mol/L NaCl), and the addition time of the strip solution was varied (0, 1 and 2 h). The time-dependent experiments showed a notable influence on the composition, structure, morphology and crystallinity of the two-dimensional vanadate products. Inspired by these findings, we selected two metallic vanadate products and studied their properties as alternative cathode materials for nonaqueous sodium and lithium metal batteries. [ABSTRACT FROM AUTHOR]

Low Coulombic efficiency and significant capacity decay resulting from an unstable solid electrolyte interphase (SEI) and dendritic growth pose challenges to the practical application of lithium‐metal batteries. In this study, a highly efficient protection layer induced by octaphenylsilsesquioxane (OPS) with LiFSI salt is investigated. The OPS exhibits a strong adsorption energy with lithium, its multi‐site gradient adsorption ability enables the simultaneous capture of 8 Li+ and the uniform regulation of Li ion flux. Moreover, the mechanical strength and electronic insulation of the OPS layer induces Li deposition under the protection layer and effectively inhibits lithium dendrite growth. Such a protection layer contributes to the stable and dendrite‐free performance of a lithium‐metal battery employing LiNi0.8Co0.1Mn0.1O2 (NCM811) as a cathode and an ultrathin OPS‐protected lithium foil (20 µm) as the anode. A remarkable capacity retention of 91.4% is achieved after 300 cycles at 1C. The OPS‐protected Li anodes and NCM811 are also tested in combination with a Li1.5Al0.5Ge1.5(PO4)3 solid electrolyte, showing extended cyclability up to 300 cycles with an average Coulombic efficiency of 99.58% and capacity retention of 85.7%. [ABSTRACT FROM AUTHOR]

Na‐ion batteries based on abundant and sustainable materials might become one of the leading alternative technologies especially suitable for large‐scale stationary storage. Various (mixed)phosphate framework materials are attracting much interest mainly due to their high structural stability and diversity. In this study, we report on the successful synthesis of mixed phosphate‐pyrophosphate Na7V4(PO4)(P2O7)4, Na4Fe3(PO4)2P2O7, and Na4Mn3(PO4)2P2O7. The electrochemical properties of these materials are comprehensively characterized in different organic and aqueous electrolytes. The findings reveal that Na7V4(PO4)(P2O7)4 and Na4Fe3(PO4)2P2O7 exhibit very good cycling performance and rate capability in organic solvent‐based electrolytes. However, their performance deteriorates significantly even in 'water‐in‐salt' aqueous electrolytes due to the rapid electrochemical degradation. Na4Mn3(PO4)2P2O7 demonstrates limited electrochemical activity in organic electrolytes and virtually no activity in 'water‐in‐salt' electrolytes, likely due to degradation processes resulting in blocking interphasial layers on electrode particles. These results underscore the need for further research to optimize the performance of these materials and identify potential strategies for enhancing their stability and activity in different electrolytes. [ABSTRACT FROM AUTHOR]

Manganese hexacyanoferrate is a promising cathode material for lithium and sodium ion batteries, however, it suffers of capacity fading during the cycling process. To access the structural and functional characteristics at the nanometer scale, fresh and cycled electrodes are extracted and investigated by transmission soft X‐ray microscopy, which allows chemical characterization with spatial resolution from position‐dependent x‐ray spectra at the Mn L‐, Fe L‐ and N K‐edges. Furthermore, soft X‐rays prove to show superior sensitivity toward Fe, compare to hard X‐rays. Inhomogeneities within the samples are identified, increasing in the aged electrodes, more dramatically in the Li‐ion system, which explains the poorer cycle life as Li‐ion cathode material. Local spectra, revealing different oxidation states over the sample with strong correlation between the Fe L‐edge, Mn L‐edge, and N K‐edge, imply a coupling between redox centers and an electron delocalization over the host framework. [ABSTRACT FROM AUTHOR]

Reactive metal‐based storage systems are a new alternative to support the clean energy transition. Herein, the cases of Al and Na are presented, both preliminarily fulfilling the constraints regarding sustainability, but employing two rather different processes. Both, the steam combustion of molten Al for H2 and heat production, and a new rechargeable battery, which makes use of seawater and sodium as electrodes, show promising round‐trip efficiencies. The latter technology also allows CO2‐trapping, desalination, Na metal, and chlorine production. It is argued that further research efforts are needed to verify the sustainability and ability of reactive metal‐based technologies to compete with other storage technologies. [ABSTRACT FROM AUTHOR]

Sodium‐metal batteries (SMBs) are considered a potential alternative to high‐energy lithium‐metal batteries (LMBs). However, the high reactivity of metallic sodium towards common liquid organic electrolytes renders such battery technology particularly challenging. Herein, we propose a multi‐block single‐ion conducting polymer electrolyte (SIPE) doped with ethylene carbonate as suitable electrolyte system for SMBs. This novel SIPE provides a very high ionic conductivity (2.6 mS cm−1) and an electrochemical stability window of about 4.1 V at 40 °C, enabling stable sodium stripping and plating and excellent rate capability of Na||Na3V2(PO4)3 cells up to 2 C. Remarkably, such cells provide a capacity retention of about 85 % after 1,000 cycles at 0.2 C thanks to the very high Coulombic efficiency (99.9 %), resulting from an excellent interfacial stability towards sodium metal and the Na3V2(PO4)3 cathode. [ABSTRACT FROM AUTHOR]

Sodium‐metal batteries (SMBs) are considered a potential alternative to high‐energy lithium‐metal batteries (LMBs). However, the high reactivity of metallic sodium towards common liquid organic electrolytes renders such battery technology particularly challenging. Herein, we propose a multi‐block single‐ion conducting polymer electrolyte (SIPE) doped with ethylene carbonate as suitable electrolyte system for SMBs. This novel SIPE provides a very high ionic conductivity (2.6 mS cm−1) and an electrochemical stability window of about 4.1 V at 40 °C, enabling stable sodium stripping and plating and excellent rate capability of Na||Na3V2(PO4)3 cells up to 2 C. Remarkably, such cells provide a capacity retention of about 85 % after 1,000 cycles at 0.2 C thanks to the very high Coulombic efficiency (99.9 %), resulting from an excellent interfacial stability towards sodium metal and the Na3V2(PO4)3 cathode. [ABSTRACT FROM AUTHOR]

Lithium metal is a promising anode material for next‐generation high‐energy‐density batteries but suffers from low stripping/plating Coulombic efficiency and dendritic growth particularly at sub‐zero temperatures. Herein, a poorly‐flammable, locally concentrated ionic liquid electrolyte with a wide liquidus range extending well below 0 °C is proposed for low‐temperature lithium metal batteries. Its all‐anion Li+ solvation and phase‐nano‐segregation solution structure are sustained at low temperatures, which, together with a solid electrolyte interphase rich in inorganic compounds, enable dendrite‐free operation of lithium metal anodes at −20 °C and 0.5 mA cm−2, with a Coulombic efficiency of 98.9 %. As a result, lithium metal batteries coupling thin lithium metal anodes (4 mAh cm−2) and high‐loading LiNi0.8Co0.15Al0.05O2 cathodes (10 mg cm−2) retain 70 % of the initial capacity after 100 cycles at −20 °C. These results, as a proof of concept, demonstrate the applicability of locally concentrated ionic liquid electrolytes for low‐temperature lithium metal batteries. [ABSTRACT FROM AUTHOR]

Lithium metal is a promising anode material for next‐generation high‐energy‐density batteries but suffers from low stripping/plating Coulombic efficiency and dendritic growth particularly at sub‐zero temperatures. Herein, a poorly‐flammable, locally concentrated ionic liquid electrolyte with a wide liquidus range extending well below 0 °C is proposed for low‐temperature lithium metal batteries. Its all‐anion Li+ solvation and phase‐nano‐segregation solution structure are sustained at low temperatures, which, together with a solid electrolyte interphase rich in inorganic compounds, enable dendrite‐free operation of lithium metal anodes at −20 °C and 0.5 mA cm−2, with a Coulombic efficiency of 98.9 %. As a result, lithium metal batteries coupling thin lithium metal anodes (4 mAh cm−2) and high‐loading LiNi0.8Co0.15Al0.05O2 cathodes (10 mg cm−2) retain 70 % of the initial capacity after 100 cycles at −20 °C. These results, as a proof of concept, demonstrate the applicability of locally concentrated ionic liquid electrolytes for low‐temperature lithium metal batteries. [ABSTRACT FROM AUTHOR]

Bilayered nanostructured V2O5·nH2O is one of the few insertion materials able to reversibly intercalate mono‐ and multivalent cations. Therefore, V2O5·nH2O is particularly attractive for the development of post Li‐ion batteries based on multi‐electron reactions. In article number 1600868, Stefano Passerini and Arianna Moretti describe the research progress over the last 30 years on the use of this versatile material as electrode for rechargeable batteries. [ABSTRACT FROM AUTHOR]

Abstract In this study, the interplay between the electrochemical behavior, structural modifications and volumetric changes of graphite-based negative electrodes for sodium ion batteries is evaluated. The electrolyte solvents chosen for this study are ethylene glycol dimethyl ether (DME), diethylene glycol dimethyl ether (DEGDME), triethylene glycol dimethyl ether (TriGDME), and tetraethylene glycol dimethyl ether (TEGDME) while the salt is sodium trifluoromethanesulfonate (NaOTf). The volume changes undergone upon co-(de)intercalation of the [Na-solvent]+ complexes are systematically investigated by means of in situ electrochemical dilatometry and correlated to the structural modification of the graphite crystalline lattice as detected by in situ X-ray diffraction. The expected staging mechanism upon co-intercalation, leading to the formation of stage-I graphite intercalation compound, is observed with all electrolytes. However, the various solvents play a substantial role on the reversibility of such structural changes in the first cycle. The effect of temperature is also investigated showing that the most stable electrochemical performance is observed with the TEGDME at room temperature, but with TriGDME at higher temperatures. Nonetheless, post-mortem scanning electron microscopy suggests that the surface layer forming after the first sodiation may dissolve in the following de-sodiation. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

The distribution of degradation products, before and after cycling, within common sulfide-based solid electrolytes (β-Li3PS4, Li6PS5Cl and Li10GeP2S12) was mapped using Raman microscopy. All composite electrodes displayed the appearance of side reaction products after the initial charge-discharge cycle, located at the site of a LiNi0.6Mn0.2Co0.2O2 particle. [ABSTRACT FROM AUTHOR]

Aluminum–sulfur batteries employing high‐capacity and low‐cost electrode materials, as well as non‐flammable electrolytes, are promising energy storage devices. However, the fast capacity fading due to the shuttle effect of polysulfides limits their further application. Herein, alkaline chlorides, for example, LiCl, NaCl, and KCl are proposed as electrolyte additives for promoting the cyclability of aluminum–sulfur batteries. Using NaCl as a model additive, it is demonstrated that its addition leads to the formation of a thicker, NaxAlyO2‐containing solid electrolyte interphase on the aluminum metal anode (AMA) reducing the deposition of polysulfides. As a result, a specific discharge capacity of 473 mAh g−1 is delivered in an aluminum–sulfur battery with NaCl‐containing electrolyte after 50 dis‐/charge cycles at 100 mA g−1. In contrast, the additive‐free electrolyte only leads to a specific capacity of 313 mAh g−1 after 50 cycles under the same conditions. A similar result is also observed with LiCl and KCl additives. When a KCl‐containing electrolyte is employed, the capacity increases to 496 mA h g−1 can be achieved after 100 cycles at 50 mA g−1. The proposed additive strategy and the insight into the solid electrolyte interphase are beneficial for the further development of long‐life aluminum–sulfur batteries. [ABSTRACT FROM AUTHOR]

This perspective article discusses the most recent developments in the field of hybrid electrolytes, here referred to electrolytes composed of two, well-defined ion-conducting phases, for high energy density lithium metal batteries. The two phases can be both solid, as e.g., two inorganic conductors or one inorganic and one polymer conductor, or, differently, one liquid and one inorganic conductor. In this latter case, they are referred as quasi-solid hybrid electrolytes. Techniques for the appropriate characterization of hybrid electrolytes are discussed emphasizing the importance of ionic conduction and interfacial properties. On this view, multilayer systems are also discussed in more detail. Investigations on Lewis acid-base interactions, activation energies for lithium-ion transfer between the phases, and the formation of an interphase between the components are reviewed and analyzed. The application of different hybrid electrolytes in lithium metal cells with various cathode compositions is also discussed. Fabrication methods for the feasibility of large-scale applications are briefly analyzed and different cell designs and configurations, which are most suitable for the integration of hybrid electrolytes, are determined. Finally, the specific energy of cells containing different hybrid electrolytes is estimated to predict possible enhancement in energy with respect to the current lithium-ion battery technology. [ABSTRACT FROM AUTHOR]

Abstract: Cathode configurations reported herein are alternative to the most diffused ones for application in lithium‐oxygen batteries, using an ionic liquid‐based electrolyte. The electrodes employ high surface area conductive carbon as the reaction host, and polytetrafluoroethylene as the binding agent to enhance the oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) reversibility. Roll‐pressed, self‐standing electrodes (SSEs) and thinner, spray deposited electrodes (SDEs) are characterized in lithium‐oxygen cells using an ionic liquid (IL) based electrolyte formed by mixing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt and N,N‐diethyl‐N‐(2‐methoxyethyl)‐N‐methylammonium bis(trifluoromethanesulfonyl)imide (DEMETFSI). The electrochemical results reveal reversible reactions for both electrode configurations, but improved electrochemical performance for the self‐standing electrodes in lithium‐oxygen cells. These electrodes show charge/discharge polarizations at 60 °C limited to 0.4 V, with capacity up to 1 mAh cm−2 and energy efficiency of about 88 %, while the spray deposited electrodes reveal, under the same conditions, a polarization of 0.6 V and energy efficiency of 80 %. The roll pressed electrode combined with the DEMETFSI‐LiTFSI electrolyte and a composite LixSn‐C alloy anode forms a full Li‐ion oxygen cell showing extremely limited polarization, and remarkable energy efficiency. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries are regarded as a complementary drop-in technology to lithium-ion batteries because they promise lower cost and a higher degree of environmental friendliness. Among other reasons, these benefits come from the use of manganese-based materials, whose stabilization via cation substitution is intensively studied to improve the electrochemical performance. Although multiple elements have been considered as substituent, surprisingly, boron has not been reported for layered sodium-ion cathode materials up to date. Our investigation of layered Na 2/3 B 0.11 Mn 0.89 O 2 reveals an unexpectedly good electrochemical performance, with charge and discharge capacities of more than 175 mAh g −1 at 10 mA g −1 and 135 mAh g −1 at 500 mA g −1 . The measured capacities are among the highest ever reported for sodium-based layered oxides in the potential range of 4.0–2.0 V vs. Na/Na + . [ABSTRACT FROM AUTHOR]

Review: more than 150 refs. [ABSTRACT FROM AUTHOR]

Non‐flammable ionic liquid electrolytes (ILEs) are well‐known candidates for safer and long‐lifespan lithium metal batteries (LMBs). However, the high viscosity and insufficient Li+ transport limit their practical application. Recently, non‐solvating and low‐viscosity co‐solvents diluting ILEs without affecting the local Li+ solvation structure are employed to solve these problems. The diluted electrolytes, i.e., locally concentrated ionic liquid electrolytes (LCILEs), exhibiting lower viscosity, faster Li+ transport, and enhanced compatibility toward lithium metal anodes, are feasible options for the next‐generation high‐energy‐density LMBs. Herein, the progress of the recently developed LCILEs are summarised, including their physicochemical properties, solution structures, and applications in LMBs with a variety of high‐energy cathode materials. Lastly, a perspective on the future research directions of LCILEs to further understanding and achieve improved cell performances is outlined. [ABSTRACT FROM AUTHOR]