Main goal of the diploma thesis is to examine lead-acid accumulator and to study cycling modes in different setups. Theoretical part describes history, types of maintenance-free batteries, degradation mechanisms and possibilities to remove them. Practical part involves the production of electrodes and experimental cell, composition of active mass and measurement of internal resistance. Different configurations for deep cycling are researched as well. The results of the work are summarized and commented at the conclusion of the thesis.

This thesis deals with the liquid aprotic electrolytes with solvent on the basis of sulfolane blends with other solvent, in combination with the sodium and lithium salts. In these electrolytes are evaluated their properties due to their use in lithium - ion batteries in terms of safety and electrical properties. For safety risk is measured flashpoint and for electrical properties is measured electrical conductivity for selected samples are intended capacities of double layers.

The dissertation thesis deals with electrode materials and components for lithium-ion power sources. The thesis works with two different kinds of materials, concretely nanostructured Li4Ti5O12 with spinel basis and LiCoO2 with layered structure. The electrochemical properties, structure and element analysis and utilization possibilities in electrochemical industry of new technological electrode material Li4Ti5O12 were investigated. The influences of admixtures and electrolytes on characteristics of electrode materials with aforesaid active masses were also examined. Low cost price, environmental safety and obtained results of electrochemical measurements and structure analysis refer to wide possibilities of usage electrode material Li4Ti5O12 in the field of electrochemistry.

The fabrication of transient electronic devices based on non-toxic materials is an emerging field, in which the key characteristic is the complete dissolution of the devices within a settled period of time. Usually, these devices are built in polymeric substrates or pure metals; however they show some disadvantages such as low degradation rate. The aim of this work was to investigate the feasibility of electrodeposition of FeMn-based films from green sulfate-based aqueous electrolytes without and with the use of additives toward the possible replacement of the aforementioned materials. The results obtained from the first experiments regarding the electrodeposition of Fe and Mn as single metals allowed the design of the experiment to synthesize FeMn layers. Potentiostatic deposition of metallic Mn layers from environmentally friendly aqueous manganese sulphate electrolytes with a pH value of 3 was successfully demonstrated. A continuous flow in the cathodic compartment of the electrochemical cell to control the pH value during the electrodeposition experiments was found to be essential for achieving good layer qualities. It also allowed the co-electrodeposition with a second element, Fe, which also needs an acidic pH value to be electrodeposited from aqueous electrolytes. Cyclic voltammetry analyses were performed in combination with electrochemical quartz microbalance measurements in the MnSO4 containing electrolytes and a suitable deposition potential range was identified. The electrolyte composition played an important. The addition of H3BO3 provided mechanical stability to the Mn films and avoided their disintegration. An increase of the (NH4)2SO4 concentration increases the deposit roughness but also the layer quality, without impurities and a better crystalline α-Mn structure. An increase of the deposition potential led to an increase of the film thickness. Mn-oxides/-hydroxides were identified only in a thin surface region of the films. The Mn electrodeposited films were deeply characterized by means of SEM, XRD, GD-OES and XPS. The results related to the Mn electrodeposition allowed further design of the electrolytes and experiments to electrochemically synthesize FeMn layers. The assessment of the impact of the electrodeposition parameters on the structural, morphological and magnetic properties of the obtained films was also aimed in this work. With view to possible application of FeMn-based films in transient devices, their corrosion behavior in chloride-containing solution and their cytotoxicity were also evaluated. The electrolytes were characterized by means of CV and EQCM analyses. The ratio of the metal ions Mn2+:Fe2+ and the presence of glycine as complexing agent in the electrolyte determined the layer composition. The formation of the complexes Fe(gly)+ and Mn(gly)+ established a new reduction step modifying the Fe and Mn reduction/deposition. Glycine also leaded to a better film quality. A set of magnetron co-sputtered FeMn thin films was deposited as reference in order to compare the two synthesis methods with a broader range of Mn content between 10 and 70 wt.%. Metallic electrodeposited FeMn films presented a bcc structure with a Im-3m symmetry as well as the sputtered samples with a low Mn content up to 25 wt.%. An increase of the Mn content in the electrodeposited layers yielded to the formation of oxidized compounds with a fcc structure and Fm-3m symmetry. An increase in the Mn content for the sputtered films maintained the bcc structure but the symmetry was lowered to I-43m. With view to possible application of FeMn-based films in transient devices, their corrosion behavior in chloride-containing solution and their cytotoxicity were also evaluated. Regarding their corrosion behaviour, both techniques produced FeMn films with an active dissolution behaviour in chloride containing solutions. In vitro cytotoxicity tests revealed significant biocompatible characteristics of the sputtered films regardless of their Mn content. However, electrodeposited FeMn based layers did not presented optimal biocompatible characteristics. Furthermore, template-assited electrodeposition to obtain microrobots was studied in this work. Observed confinement effect was exploited, which results in compositional gradients with Mn-rich and Fe-rich regions and tubular or mushroom-like shapes. The propulsion performance of these electrochemically prepared hybrid micromotors was studied in the presence of H2O2 fuel with Triton-X as a surfactant and a magnetic field of 23.5 mT was applied. Bubbles produced by the catalytic decomposition of the H2O2 by the MnO2 and MnFe2O4 compounds was clearly the motion mechanism. Wireless modulated trajectory by the application of an external magnetic field was possible thanks to the magnetic phases, Fe3O4 and MnFe2O4.

The essence of this graduate thesis is to summarize knowledge about the aprotic gel electrolytes. In the graduate thesis, there are explained methods for mensuration electrochemical properties of the aprotic gel electrolytes. In the theoretical part, I focus on the knowledge related to gel polymeric electrolytes, their history, properties, mechanisms and application. In the experimental part, I describe the preparation of the samples of the gel polymeric electrolytes, in which I evaluate their properties, electrical conductivity and potencial window.

Im Rahmen des Postgradual-Studienganges (PGS) „Toxikologie und Umweltschutz“ wird das interaktive Lernprogramm „Toxnetz-Explorer“ entwickelt. Anhand von Grafiken, Animationen und unterstützenden Texten sollen die wichtigsten Funktionen des menschlichen Körpers und einzelner Organe sowie der Zusammenhang dieser mit toxikologischen Vorgängen veranschaulicht werden. Die vorliegende Arbeit stellt die Basis des Abschnittes über die Niere für das Lernprogramms „Toxnetz-Explorer“ dar. Die Nieren sind die zentralen Ausscheidungsorgane des menschlichen Körpers. Alle löslichen Verbindungen werden in der Niere filtriert, dem Körper über unterschiedliche Prozesse zurückgeführt, metabolisiert oder ausgeschieden. Darüber hinaus besitzt die Niere weitere regulierende Aufgaben, wie beispielsweise die Regulation des Wasser-Elektrolyt- oder des Säure-Haushaltes. Sie sind ebenfalls für die Autoregulation des renalen Blutdruckes und die Synthese von verschiedenen Substanzen verantwortlich. Auf Grund dieser vielen und wichtigen Funktionen und der hohen Durchblutungsrate sowie der Aufkonzentrierung von Substanzen stellen die Nieren ein attraktives Ziel für ein große Anzahl an toxischen Stoffen dar, welche an die verschiedenen renalen Funktionseinheiten eine Schädigung bewirken können. Ziel dieser Arbeit ist die anschauliche Darstellung des anatomischen Aufbaus der Niere, der normalen renalen Funktionen und Aufgaben im menschlichen Körper, sowie eine Zusammenstellung verschiedener nephrotoxischen Substanzen und deren spezifischen Schädigungsmechanismen.

Increasing energy demand draws attention to new materials for improving current energy storage technologies. Particular interest is directed at solid state batteries and glass Na3ClO electrolyte is a promising candidate. In this report we explore some of the properties of this new glass and its capabilities as a potential electrolyte for a solid-state battery. The two aims of the study were to model the amorphous structure of the glass using the stochastic quenching method based on density functional theory as well as assessing the electrochemical stability of it against a metallic sodium electrode. Using VASP, a computational code based on density functional theory, we performed calculations of two 150 atom supercells, where the atoms were moved around until the systems were relaxed to obtain two glass models and the resulting structures were analyzed and characterized. The characterization of the structures was made by means of partial radial distribution functions, angle distribution functions, coordination numbers and bond lengths, which showed that the two models are statistically equivalent and either one can be used for the stability assessment of the glass. The electrochemical stability was assessed by inserting an extra sodium atom in possible holes in the glass model and calculating the energetics of Na insertion in each of these holes. This was made for 30 different hole positions. The reduction potential indicates the stability of each hole and the results was plotted as an energy distribution. Two peaks in the energy distribution, located at positive and negative energies, indicating stable and unstable holes, respectively. This indicates that the amorphous structure of the glass allows Na ions to travel (unstable holes). The stable peak has a greater probability density, which indicates a stable electrolyte against sodium metal electrode, though a larger sampling of holes is required for better statistics. / Ökande krav på energiefterfrågan uppmärksammar nya material för att förbättra nuvarande energilagringsteknik, med fokus på solida batterier och glaset Na3ClO som en lovande kandidat för elektrolyt. I denna rapport undersöks några av egenskaperna för glaset samt möjligheten för denna att fungera som elektrolyt i ett solid-state batteri. Målen med projektet var att modellera den amorfa strukturen av glaset genom att använda stochastic quenching method som baseras på density functional theory samt undersöka den elektrokemiska stabiliteten mot en metallisk natrium elektrod. Genom användning av VASP, beräkningskoder baserade på density functional theroy, beräknades två superceller med 150 atomer vardera där atomerna flyttas runt tills dess att systemet var relaxerat och två modeller av glaset erhölls. Dessa var sedan visualiserades och karakteriserade. Karakterisering av strukturerna gjordes genom en partiella radiella fördelningsfunktioner, vinkel distrubitionsfunktioner, koordinationsnummer och bindningslängder. Detta visade på statistisk ekvivalens, vilket innebär att båda modellerna kan användas för vidare stabilitetsundersökning. Den elektrokemiska stabiliteten undersöktes genom att sätta in en extra natrium atom i möjliga hål i glas modellen samt beräkna dess energier av Na insättning i respektive hål. Detta gjordes för 30 olika positioner för hålen. Reduktionspotentialen indikerar stabiliteten för respektive hål, och resultatet plottades som en energidistribution. Två toppar i energidistributionen, lokaliserade vid positiva och negativa energier, indikerar stabila respeltive instabila hål. Detta indikerar på att den amorfa strukturen för glaset tillåter Na joner att färdas (instabila hål). Den stabila toppen har en större sannolikhetstäthet vilket indikerar på en stabil elektrolyt mot en metallisk natrium elektrod, men en större samling hål krävs för en bättre statistisk säkerhet.

Solid-state batteries are gaining a lot of attention in the commecial sector today. Development of the solid state electrolytes is an important part in making commercially viable solid-state batteries. While many solid-state electrolytes are struggling with low ionic conductivity, some have shown comparatively high conductivities that can be engineered to perform better to be implemented for consumer market. Silica based solid composite electrolytes (SCEs) are one of the materials that are of huge interest as solid-state electrolytes. As a continuation of the previous research into the silica based SCE’s, the current work focuses on the study of SCEs based on the commercially available mesoporous silica (MPS) of different pore sizes and nanosized silica powder (SNP). Ionic Liquid electrolyte (ILE) based on Li-TFSI and BMP-TFSI mixture was used to prepare composities under different humidity conditions. The effect of the extent of -OH group functionalization of silica, determined by FTIR on treated and untreated powders, on ionic conductivity was also evaluated. Obtained composities were evaluated with electrochemical impedance spectroscopy (EIS) and analysed with TGA to establish correlations based on particle size and pore characteristics of MPS powder. Camparison with SNP was also made in anticipation to draw correlations with MPS. It was found that the pore size and pore volume change have more impact on the conductivity compared to surafce area of commercially obtained MPS and an unexplored pheonomenon was observed in case of SNP based SCE’s. Glovebox (GB) samples at relative humidity (RH)-0.005% have higher conductivity than dryroom samples at RH-0.5%. These findings can be used for a future reference in evaluating commercial MPS based composites as solid-state electrolytes. / Solid-state-batterier får stor uppmärksamhet i den kommersiella sektorn idag. Utveckling av fasta elektrolyter är en viktig del för att göra kommersiellt gångbara solid state-batterier. Medan många fasta elektrolyter kämpar med låg jonledningsförmåga, har vissa visat jämförelsevis höga ledningsförmåga som kan konstrueras för att prestera bättre för att implementeras för konsumentmarknaden. Kiselbaserade fasta kompositelektrolyter (SCE) är ett av de material som är av stort intresse som fasta elektrolyter. Som en fortsättning på den tidigare forskningen om de kiselbaserade SCE:erna fokuserar det nuvarande arbetet på studiet av SCE:er baserade på den kommersiellt tillgängliga mesoporösa kiseldioxiden (MPS) av olika porstorlekar och nanosized kiseldioxidpulver (SNP). Jonisk flytande elektrolyt (ILE) baserad på Li-TFSI och BMP-TFSI-blandning användes för att framställa kompositer under olika luftfuktighetsförhållanden. Effekten av omfattningen av -OH-gruppfunktionalisering av kiseldioxid, bestämd med FTIR på behandlade och obehandlade pulver, på jonkonduktiviteten utvärderades också. Erhållna sammansättningar utvärderades med elektrokemisk impedansspektroskopi (EIS) och analyserades med TGA för att fastställa korrelationer baserat på partikelstorlek och poregenskaper hos MPS-pulver. Kamparison med SNP gjordes också i väntan på att dra korrelationer med MPS. Det visade sig att porstorleken och porvolymsförändringen har mer inverkan på konduktiviteten jämfört med ytan för kommersiellt erhållen MPS och ett outforskat fenomen observerades i fallet med SNP-baserade SCE. Handskbox (GB) prover vid relativ fuktighet (RH)-0,005 % har högre konduktivitet än torrrumsprover vid RH-0,5 %. Dessa resultat kan användas för en framtida referens vid utvärdering av kommersiella MPS-baserade kompositer som fasta elektrolyter.

Ion-exchange membranes, conventionally utilized in separation processes of electrolyte solutions, are electroactive polymers that display a unique coupling between electrochemistry and mechanics. Previous experimental studies have demonstrated the possibility of actuating cation-exchange membranes in salt solution through the application of a remote external electric field. The use of anion-exchange membranes as contactless actuators, however, has never been documented and little is known about the physics of their actuation. Here, it is reported for the first time the possibility of contactless actuating anion-exchange membranes in salt solutions; such an actuation is mediated by the selection of anions in the external salt solution and the membrane. Actuation is attributed to the physical phenomenon of solvation, the interaction between ions and solvent in solution. Contrary to previous studies with cation-exchange membranes, the results show that anion-exchange membranes consistently bend toward the anode. The integration of anion-exchange and cation-exchange membranes in composites promises innovative programmable contactless actuators, with applications in underwater robotics and biomedical engineering.

This paper reports a novel and remarkably facile approach towards vertically aligned nanosheets on three-dimensional (3D) Ni foams. Conducting polypyrrole (PPy) sheets were grown on Ni foam through the volatilization of the environmentally friendly solvent from an ethanol–water solution of pyrrole (Py), followed by the polymerization of the coated Py in ammonium persulfate (APS) solution. The PPy-decorated Ni foams and commercial activated carbon (AC) modified Ni foams were employed as the two electrodes for the assembly of flexible all-solid-state asymmetric supercapacitors. The sheet-like structure of PPy and the macroporous feature of the Ni foam, which render large electrode–electrolyte interfaces, resulted in good capacitive performance of the supercapacitors. Moreover, a high energy density of ca. 14 Wh kg−1 and a high power density of 6.2 kW kg−1 were achieved for the all-solid-state asymmetric supercapacitors due to the wide cell voltage window.