Increasing energy demands world-wide must be met with more effective systems to produce, store, and distribute energy. Ideally, these systems should avoid fossil fuels and incorporate renewable technologies. To accommodate for the intermittent nature of renewable energies, a rechargeable gallium-air flow battery system for electrical grid applications is suggested. Using liquid gallium-air flow batteries could meet the rigorous world-wide demands for storage capacity, discharge duration, and durability necessary for the electrical grid. Toward this goal, a batch gallium-air battery was build and investigated. The performance of the system has been incrementally improved to a 30 hour discharge duration. Some insights into the mechanism of the gallium-air reaction was also obtained. However, recharging experiments were mostly unsuccessful. Despite the failures caused by carbonation and the separator drying, the Ga-Air system remains promising.

none

Battery pack imbalance is one of the most pressing issues for companies involved in Battery Energy Storage. The importance of Battery Balancing with respect to Xtreme Power has been analysed in detail. Various methods of Battery Balancing have been researched and presented. Methods that were the most suitable to Xtreme Power's battery pack topology were selected and tested. The results of these experiments are presented and relevant conclusions are shown. / text

The chemical vapor deposition growth of amorphous metallic alloys is currently of interest for potential uses in electronic devices. We have explored the use of ligands having Ru-H, Ru-N, and Ru-P bonds to study the effects of ligand selection. The synthesis and design of novel Ru dinuclear complexes using volatile ligands such as 3,5-bis-trifluoromethylpyrazolate and trimethylphosphine will be presented as well as materials characterization studies on grown films. Another class of functional materials of interest is the transition metal phosphides (TMPs) which have found applications in Li-ion batteries. Current research on TMPs is focused on obtaining materials with improved or new compositions and morphologies and on improving Li insertion/de-insertion reactions and charge carrying capacities. Traditional routes to these materials involve the use of high temperatures and pressures. The work presented here will focus on a synthetic route which employs relatively mild conditions. Surface analysis studies and the electrochemical performance of mesoporous MoP₄ for use as anode materials in Li-ion batteries will be described. / text

The ever increasing awareness of the environment and sustainability drives research to find new solutions in every part of society. In the transport sector, this has led to a goal of replacing the internal combustion engine (ICE) with an electrical engine that can be powered by renewable electricity. As a battery for vehicles, the Li-ion chemistries have become dominant due to their superior volumetric and gravimetric energy densities. While promising, electric vehicles require further improvements in terms of capacity and power output before they can truly replace their ICE counterparts. Another aspect is the CO2 emissions over lifetime, since the electric vehicle itself presently outlives its battery, making battery replacement necessary. If the lifetime of the battery could be increased, the life-cycle emissions would be significantly lowered, making the electric vehicle an even more suitable candidate for a sustainable society. In this context, lithium titanium oxide (LTO) has been suggested as a new anode material in heavy electric vehicles applications due to intrinsic properties regarding safety, lifetime and availability. The LTO battery chemistry is, however, not fully understood and fundamental research is necessary for future improvements. The scope of this project is to investigate degradation mechanisms in LTO-based batteries to be able to mitigate these and prolong the device lifetime so that, in the end, a suitable chemistry for large scale applications can be suggested. The work presented in this licentiate thesis is focused on the LTO electrode/electrolyte interface. Photoelectron spectroscopy (PES) was applied to determine whether the usage of LTO would prevent anode-side electrolyte decomposition, as suggested from the intercalation potential being inside the electrochemical stability window of common electrolytes. It has been found that electrolyte decomposition indeed occurs, with mostly hydrocarbons of ethers, carboxylates, and some inorganic lithium fluoride as decomposition products, and that this decomposition to some extent ensued irrespective of electrochemical battery operation activity. Second, an investigation into how crossover of manganese ions from Mn-based cathodes influences this interfacial layer has been conducted. It was found, using a combination of high-energy x-ray photoelectron spectroscopy (HAXPES) and near-edge x-ray absorption fine structure (NEXAFS) that although manganese is present on the LTO anode surface when paired with a common manganese oxide spinel cathode, the manganese does little to alter the surface chemistry of the LTO electrode.

Batteries are important energy storage devices and are used in different applica- tions. The purpose of this thesis is to study behavior and characteristics of batter- ies when used in system-level design process. In addition, the use of hardware-in- loop (HIL) simulation of batteries for power system applications is studied. The thesis also aims to investigate the ability of HIL in alleviating the need for extensive and detailed modeling of battery storage systems and to improve the accuracy of the simulation of systems where they are used. The major problem of using battery models is that they are greatly aff ected by external factors such as temperature and history of the charge/discharge regimes. An HIL scheme eliminates the need for mathematical modeling of batteries by interfacing them directly to the simula- tor, where charging and discharging regimes, state of charge estimation methods and efficiency can be investigated.

No description available.

No description available.

Batteries are important energy storage devices and are used in different applica- tions. The purpose of this thesis is to study behavior and characteristics of batter- ies when used in system-level design process. In addition, the use of hardware-in- loop (HIL) simulation of batteries for power system applications is studied. The thesis also aims to investigate the ability of HIL in alleviating the need for extensive and detailed modeling of battery storage systems and to improve the accuracy of the simulation of systems where they are used. The major problem of using battery models is that they are greatly aff ected by external factors such as temperature and history of the charge/discharge regimes. An HIL scheme eliminates the need for mathematical modeling of batteries by interfacing them directly to the simula- tor, where charging and discharging regimes, state of charge estimation methods and efficiency can be investigated.

Large specific gravimetric/volumetric energy density, environmental benignity and safe low working voltage. All of these points have been used to describe the lithium sulfur (Li-S) battery in the past, but often times it is short cycle life and poor capacity retention that is associated with the Li-S battery. In order to realize the full potential of the Li-S battery in society today, many obstacles must be overcome. In a typical Li-S cell with an organic liquid electrolyte sulfur is reduced by lithium during discharge and subsequent lithium polysulfide species (Li2Sx where x, 2 < x < 8) are formed. These species are readily soluble in typical organic electrolytes and can lead to low Coulombic efficiency and most challenging: active mass loss. Through the loss of active mass, rapid capacity fading occurs over long-term cell cycling. Overcoming the loss of active mass and stabilizing cell capacity at high rates is pivotal to the realization of practical Li-S cells. In this thesis, four separate concepts and materials were studied and prepared with the aim to improve the Li-S batteries capacity, cycle life and capacity retention.