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[en] Used as low-cost anode in the majority of lithium ion batteries, layered graphite has got critical issues. Owing to its low voltage operation, they reduce electrolyte by stealing lithium from cathode to form an SET (Solid Electrolyte Interphase), and pose fire risk from dendrite based short-circuit likely at times of fast charging or erroneous over-lithiation towards end of discharge. In this talk we are addressing this problems
[en] Carbon, as a technologically important material, is attracting much attention due to its application in electrochemical devices based on energy storage/conversion. Carbon has the unique characteristics that comes from the fact that the simple change in its surface or local bonding give rise to a new type of carbon with entirely different performance. Carbon materials have a remarkable range of electrical, optical, and electrochemical properties which primarily depends on the texture and surface chemistry. Among carious carbon materials Graphene is attracting much attention in energy storage devices especially supercapacitors where charge storage takes place by accumulation of ionic charges at the surface and pseudo capacitance
[en] The thermal safety of batteries and of other energy storage devices (ESD) is among their most important characteristics. Thermal analysis and calorimetry testing, whether it aims at improving the thermal stability of ESD materials (cathodes, anodes, electrolytes, separators) or at determining heat management data (heat capacity, heat release) of ESD, is highly valuable from the point of view of thermal safety. Thermogravimetric Analysis (TGA) measures mass change of ESD materials as a function of temperature when they are heated, and detects materials reactivity. Its combination with evolved gas analysis techniques is particularly interesting for the investigation of the chemistry of the reaction, owing to the identification of the species evolved during the mass change
[en] Ionic Liquid (IL) [EMIMBF4] and lithium salt [LiPF6] based quasi solid-liquid electrolytes (QS-LEs; viz. Ionogels) were synthesized using physical imbibition process of IL-salt solution in ordered mesoporous SBA-15. Ionogel Electrolytes so prepared have high ionic conductivity and lithium transference number (tLi+). The synthesized quasi solid-liquid electrolytes were characterized by N2-sorption, SEM, TEM, TGA, and complex impedance spectroscopy techniques. N2-sorption technique, TEM and SEM results confirm the adsorption of ionic liquid and lithium salt in the ordered mesoporous channels and on the external surface of SBA-15
[en] Rechargeable Lithium/Sodium-ion batteries that deliver higher energy and power densities are highly essential to meet the growing energy demand from portable electronics and automotive sectors. In this regard, trade-off between specific energy and power densities in these systems needs to be addressed with newer storage mechanisms. Designing efficient anode and cathode materials with improved kinetics and long cycle life is important to realize the practical implementation of this technology. Here, some of our recent efforts on the design and fabrication of hybrid nanostructured electrode materials for sodium-ion batteries and hybrid ion capacitors will be discussed and some of the key challenges will be addressed. Further, our recent studies on the design and synthesis of tailored polyimide based electrodes for organic-based sodium-ion batteries will also be presented. (author)
[en] The climatic variation and deteriorating availability of fossil fuels needs to move the society towards renewable sources. The supercapacitor will become an attractive power solution to the increasing number of applications, such as renewable energy power generation, transportation, power system and many others, because of its advantages, which include high charge/discharge current capability, very high efficiency, wide temperature range, etc. Thus, supercapacitor is an emerging technology in the field of energy storage systems that can offer higher power density than batteries and higher energy density over traditional capacitors. In other words, one can say, it actually fills the gap between the batteries and conventional capacitors. Many metal oxides/ hydroxides have been studied extensively for the application of supercapacitor. The RuO2 is studied widely for sup supercapacitor, it also shows great performance as supercapacitor, but the costing and toxicity are the basic problems with this material and other oxide/ hydroxide material. Therefore, we have to move towards the alternative way, that is, cost as well as environment friendly material. The strontium hydroxide (Sr(OH)2) with tuberose dendritically branched structures has been grown successfully by successive ionic layer adsorption and reaction (SILAR) method at room temperature without using any surfactant or binder. The Sr(OH)2 film electrode exhibited the specific capacity of 413Cg-1 at 2 Ag-1 in 1 M NaOH electrolyte. The Sr(OH)2 can be emerged as a promising electrode material for supercapacitor application synthesized by low cost chemical method applicable to roll-to-roll technology, portable electronics, electric vehicles, large scale energy storage grid, etc. (author)
[en] Rechargeable all-solid-state (ASSB), batteries are attractive power sources for applications like smart credit cards and medical implants and can work at room as well as elevated temperatures. Finding a suitable solid electrolyte with high ionic conductivity is a pivotal issue for building practical solid-state batteries. There have been numerous developments on materials such as lithium rich sulfide glasses as solid electrolyte. However, limited current density remains a major impediment in these electrolyte systems
[en] Even though graphene and its variants are expected to possess enhanced rate capability and Li-storage capacity, as compared to bulk graphite, as anode material for Li-ion battery, lack of in-depth understanding of Li-storage mechanisms has hindered their successful usage.Against this backdrop, using well-ordered CVD-grown fairly pristine few layers graphene (FLG) film as model material and performing extensive structural/electrochemical investigations, in-situ experimentations and computational studies, we have been able to develop better insights into various inter-related phenomena related to lithiation/delithiation.These understandings have also been translated towards development of reduced graphene oxide based actual electrodes
[en] In this work, new methods for characterizing the electrochemical and thermal behavior of lithium-ion cells are presented. Based on these, a modeling approach is presented that is able to represent the cell behavior in four domains (static and dynamic for electrochemical and thermal behavior) separately. This enables transferability to a wide range of material chemistries, scalable accuracy and parameterization that can be automated.
[de]In dieser Arbeit werden neue Verfahren zur Charakterisierung des elektrochemischen und thermischen Verhaltens von Lithium-Ionen Zellen vorgestellt. Basierend auf diesen wird ein Modellansatz vorgestellt, der das Zellverhalten in vier Domänen (statisch und dynamisch für elektrochemisches und thermisches Verhalten) getrennt abzubilden vermag. Hierdurch wird die Übertragbarkeit auf verschiedenste Materialchemien, skalierbare Genauigkeit und eine automatisierbare Parametrierung möglich.
[en] Wind energy is an important field of development for the island of Gotland, Sweden, especially since the island has set targets to generate 100% of its energy from renewable sources by 2025. Due to the variability of wind conditions, energy storage will be an important technology to facilitate the continued development of wind energy on Gotland and ensure a stable and secure supply of electricity. In this study, the feasibility of utilizing the Middle Cambrian Faludden sandstone reservoir on Gotland for Compressed Air Energy Storage (CAES) is assessed. Firstly, a characterization of the sandstone beneath Gotland is presented, which includes detailed maps of reservoir thickness and top reservoir structure. Analysis of this information shows that the properties of the Faludden sandstone and associated cap rock appear favorable for the application of CAES. Seven structural closures are identified below the eastern and southern parts of Gotland, which could potentially be utilized for CAES. Scoping estimates of the energy storage capacity and flow rate for these closures within the Faludden sandstone show that industrial scale CAES could be possible on Gotland.