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Lithium-ion battery performance and longevity depend critically on the conducting salt utilized in the electrolyte. With new avenues for multifunctional integration and optimization of functional properties, conducting salts beyond lithium hexafluorophosphate (LiPF6) need to be studied. Herein we elucidate on viscosity, ionicity, anion self-diffusion and ionic conductivity through variation of the length of the perfluoroalkyl side chain present in the anions of the used lithium imidazole salts. Specifically, we study LiPF6 in comparison with lithium 4,5-dicyano-2-(trifluoromethyl)imidazolide (LiTDI), lithium 4,5-dicyano-2-(pentafluoroethyl)imidazolide (LiPDI), and lithium 4,5-dicyano-2-(n-heptafluoropropyl)imidazolide (LiHDI). We find that the ion mobility of LiPF6 depends the least on viscosity and its ionicity is the highest among the electrolytes investigated here. LiTDI shows the strongest correlation between ion mobility and viscosity and the lowest ionicity. LiPDI and LiHDI range between these two regarding their ionicity and the correlation of mobility with viscosity. The previously rarely studied anion self-diffusion coefficients exhibit a strong correlation with viscosity as it was to be expected. Differences between the LiTDI, LiPDI and LiHDI salts are minute. [ABSTRACT FROM AUTHOR]

The scope of this paper is to study in detail the influence of inorganic fillers on the structure of composite polymeric electrolytes based on high-molecular weight poly(oxyethylene). It was mostly driven by large discrepancies between results reported by different authors as well as lack of detailed and complete information on the properties of composite electrolytes in the numerous articles published in the last 30 years. To enhance the transport properties—annealing steps were applied. First just below the melting point of the crystalline poly(oxyethylene) phase—at 60 °C, and then at 80 °C, 100 °C and 120 °C. They led to a dramatic increase of the ionic conductivities, for both—reference, and composite electrolytes; however, the effect was most pronounced for micron-sized fillers. On the other hand, nano-powders filled samples exhibited the best mechanical stability. To study the mechanism of the conductivity enhancement, combined X-ray diffraction (XRD) and differential scanning calorimetry (DSC) studies were conducted. Appearance, disappearance, and changes in relative volume of different phases present in the electrolytes were observed. These are the first-reported results showing such changes upon annealing. Since these are multiphase systems and no obvious space groups can be applied to study the changes in the diffractograms, correlation analysis was employed to investigate this phenomenon. [ABSTRACT FROM AUTHOR]

Beyond liquid electrolytes, the development of other electrolyte systems is needed to cover all needs for novel batteries suited for detailed usage. Lithium polymer electrolytes for next-generation batteries cover a broad range of emerging energy applications, including their further investigation of solid polymer ionic conductors. Possibility of transferring Li+ cations through the unique polymer structure forces modifications of a solid polymer electrolyte. The host matrix is immobile, while long-range cation transport must involve dissociative steps where solvated cations are transferred between neighboring coordination sites, in combination with migration and diffusion of ion aggregates weakly coordinated to the polymer solvent. Most of the current models can be successfully applied to amorphous monophase systems. There are many concepts leading to the increase in flexibility, conductivity performance, and extended storage time for several months, which might be useful for even very demanding battery applications. This review provides readers with a comprehensive background for understanding current knowledge and opportunities for lithium polymer electrolytes. [ABSTRACT FROM AUTHOR]

Battery research initiatives and giga‐scale production generate an abundance of diverse data spanning myriad fields of science and engineering. Modern battery development is driven by the confluence of traditional domains of natural science with emerging fields like artificial intelligence and the vast engineering and logistical knowledge needed to sustain the global reach of battery Gigafactories. Despite the unprecedented volume of dedicated research targeting affordable, high‐performance, and sustainable battery designs, these endeavours are held back by the lack of common battery data and vocabulary standards, as well as, machine readable tools to support interoperability. An ontology is a data model that represents domain knowledge as a map of concepts and the relations between them. A battery ontology offers an effective means to unify battery‐related activities across different fields, accelerate the flow of knowledge in both human‐ and machine‐readable formats, and support the integration of artificial intelligence in battery development. Furthermore, a logically consistent and expansive ontology is essential to support battery digitalization and standardization efforts, such as, the battery passport. This review summarizes the current state of ontology development, the needs for an ontology in the battery field, and current activities to meet this need. [ABSTRACT FROM AUTHOR]

The article describes a research on new salts and cathode materials dedicated to sodium cells. Sodium technology is considered to be one of the most promising (for new battery generations) and has been very actively (re)‐developed for more than a decade. The first part of this work is mainly focused on electrochemical studies of the low coordinating Hückel type salt (4,5‐dicyano‐2‐(trifluoromethyl)imidazolate, NaTDI)‐based electrolytes with and without solid electrolyte interface modified additives: fluoroethylene carbonate (FEC). In the second part electrolytes are tested in a half‐cells with layered oxides. Sodium nickel‐manganese‐cobalt oxide (NaNMC) and WI‐NaNMC‐333 and WI‐NaNMC‐622 layered cathode materials are prepared by wet impregnation synthesis (WI) routine. Prussian White is obtained from University of Uppsala group to compare and initial electrochemical properties against electrolyte with NaTDI. Basic physicochemical properties of the obtained powders are also reported in the manuscript. The best properties are recorded for 0.75 m NaTDI in EC:DMC (1:1 v/v) with 3% FEC additive by its conductivity (11.52 mS cm−1 for 20 °C). The same solution also shows promising results during electrochemical tests in half‐cell geometry against WI‐NaNMC‐622 cathode (114.22 mAh g−1 after 1 cycle C/20). NaPF6 salt is used as an electrolyte as a commercially available reference. [ABSTRACT FROM AUTHOR]

In this paper we present the synthesis route and electrochemical properties of new class of ionic liquids (ILs) obtained from lithium derivate TDI (4,5-dicyano-2-(trifluoromethyl)imidazolium) anion. ILs synthesized by us were EMImTDI, PMImTDI and BMImTDI, i.e. TDI anion with 1-alkyl-3-methylimidazolium cations, where alkyl meant ethyl, propyl and butyl groups. TDI anion contains fewer fluorine atoms than LiPF6 and thanks to C–F instead of P–F bond, they are less prone to emit fluorine or hydrogen fluoride due to the rise in temperature. Use of IL results in non-flammability, which is making such electrolyte even safer for both application and environment. The thermal stability of synthesized compounds was tested by DSC and TGA and no signal of decomposition was observed up to 250 °C. The LiTDI salt was added to ILs to form complete electrolytes. The structures of tailored ILs with lithium salt were confirmed by X-ray diffraction patterns. The electrolytes showed excellent properties regarding their ionic conductivity (over 3 mS cm−1 at room temperature after lithium salt addition), lithium cation transference number (over 0.1), low viscosity and broad electrochemical stability window. The ionic conductivity and viscosity measurements of pure ILs are reported for reference. [ABSTRACT FROM AUTHOR]

This work focuses on the development of an electrocatalytic material by annealing a composite of a transition metal coordination material, iron hexacyanoferrate (Prussian blue) immobilized on carboxylic-acid-functionalized reduced graphene oxide. Pyrolysis at 500 °C under a nitrogen atmosphere formed nanoporous core–shell structures with efficient activity, which mostly included iron carbide species capable of participating in the oxygen reduction reaction in alkaline media. The physicochemical properties of the iron-based catalyst were elucidated using transmission electron microscopy, X-ray diffraction, Mössbauer spectroscopy, and various electrochemical techniques, such as cyclic voltammetry and rotating ring–disk electrode (RRDE) voltammetry. To improve the electroreduction of oxygen over the studied catalytic material, an external magnetic field was utilized, which positively shifted the potential by ca. 20 mV. The formation of undesirable intermediate peroxide species was decreased compared with the ORR measurements without an external magnetic field. [ABSTRACT FROM AUTHOR]

Ni-rich layered oxides, i.e., LiNi0.6Mn0.2Co0.2O2 (NMC622) and LiNiO2 (LNO), were prepared using the two-step calcination procedure. The samples obtained at different calcination temperatures (750–950 °C for the NMC622 and 650–850 °C for the LNO cathode materials) were characterized using nitrogen physisorption, PXRD, SEM and DLS methods. The correlation of the calcination temperature, structural properties and electrochemical performance of the studied Ni-rich layered cathode materials was thoroughly investigated and discussed. It was determined that the optimal calcination temperature is dependent on the chemical composition of the cathode materials. With increasing nickel content, the optimal calcination temperature shifts towards lower temperatures. The NMC-900 calcined at 900 °C and the LNO-700 calcined at 700 °C showed the most favorable electrochemical performances. Despite their well-ordered structure, the materials calcined at higher temperatures were characterized by a stronger sintering effect, adverse particle growth, and higher Ni2+/Li+ cation mixing, thus deteriorating their electrochemical properties. The importance of a careful selection of the heat treatment (calcination) temperature for each individual cathode material was emphasized. [ABSTRACT FROM AUTHOR]

A new family of fluorine-free solid-polymer electrolytes, for use in sodium-ion battery applications, is presented. Three novel sodium salts withdiffuse negative charges: sodium pentacyanopropenide (NaPCPI), sodium 2,3,4,5-tetracyanopirolate (NaTCP) and sodium 2,4,5-tricyanoimidazolate (NaTIM) were designed andtested in a poly(ethylene oxide) (PEO) matrix as polymer electrolytes for anall-solid sodium-ion battery. Due to unique, non-covalent structural configurations of anions, improved ionic conductivities were observed. As an example, 'liquid-like' high conductivities (>1 mS cm−1) were obtained above 70 °C for solid-polymer electrolyte with a PEO to NaTCP molar ratio of 16:1. All presented salts showed high thermal stability and suitable windows of electrochemical stability between 3 and 5 V. These new anions open a new class of compounds with non-covalent structure for electrolytes system applications. [ABSTRACT FROM AUTHOR]