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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]

To meet the needs for the increasing demands for portable energy storages, the alternatives for Li-ion batteries must be researched. One of the ideas is sodium-ion technology, where the development of the novel cathodic material and electrolytes is crucial. In this paper, the new types of electrodes based on the sodium-cobalt oxide doped with yttrium or cobalt are presented. For testing them in cells, at first only two electrolytes were introduced (0.75 M NaTDI in EC:DMC and 0.75M NaTDI in EC:DMC+3% FEC). However, during experiments, the performance of some cells was poor, even after initiating the new protocol of cell assembly. That is why new formulations with the best conductivity performance, physicochemical stability, and interfacial contact with metallic sodium electrodes were used for further testing of cathodes. During the SEM, Raman, EDS, and XRPD analysis, the full characterization of the active materials and electrodes was performed and the best composition of electrode and electrolyte have been chosen basing on the electrochemical cycling of the half-cell, which achieved 143.64 mAh·g −1 discharge capacity value. Also, the metallic sodium electrode stability studies were performed to study the influence of the electrolyte on the anodic side of the cell. • Cathodes doped with 5–15% Y or Ti to the sodium-cobalt oxide were investigated. • Electrolyte formulations based on the Hückel salt were characterized. • Half-cells were tested by short-cycling and long-term performance tests. • Spectroscopic and imaging analyses of electrodes were described. • The new possible compositions of the Na-ion cells are proposed. [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]

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]