The objective of this thesis is to investigate how the onboard battery of a quadcopter can be charged through manual rotation of its motors, while understanding the resulting aerodynamical forces acting on the rotors during hover, as well as considering the changes in thrust capabilities when the electronic and structural design are altered. A theoretical approach using the momentum theory will present a general understanding of rotor performance whilst describing the correlation between rotor parameters, thrust and mechanical power. Furthermore, the idea of using the motors as generators are put under study to investigate their electrical output and utilize them to recharge the battery. This is done using the counter electromotive force equation, and a sequence of other equations that will present numerical data of actual manual work converted into electrical power. Resulting in the required time to manually recharge the quadcopter subsequently sustaining hover flight for three minutes. It is concluded in this report that manual recharging of the battery using the motors as generators is possible, as well as maintaining its flying ability in case of added weight. Although not deemed practical in commercial use, it is a new methodology with the intention to develop a sustainable quadcopter further expanding its practical applications in both aviation industry and human aid.

<p>A thermodynamically consistent coarsed-grained phase field model was developed to find the conditions under which a heterogeneous porous electrode can be treated as homogeneous in the description of Lithium-ions in rechargeable batteries. Four regimes of behavior under which the transport phenomena can be homogenized to describe porous LIBs were identied: regime (a), where the model is inaccurate, for physically accessible particle packings of aspect ratios smaller than c/a = 0.5 and electrode porosities between 0.34 to 0.45; regime (b), where the model is valid, for particles of aspect ratios greater than c/a = 0.7 and electrode porosities greater than 0.35; regime (c), where the model is valid, but the microstructures are physically inaccessible, and correspond to particles with aspect ratios greater than c/a = 0.7 and electrode porosities smaller than 0.34; and regime (d), where the model is invalid and the porous microstructures are physically inaccessible, and correspond to particles with aspect ratios smaller than c/a = 1 and electrode porosities smaller than 0.34.</p> <p>The developed formulation was applied to the graphite | LixNi1/3Mn1/3Co1/3O2 system to analyze the effect of microstructure and coarsed-grained long-range chemomechanical effects on the electrochemical behavior. Specically, quantiable lithium distribution populations in the cathode, as a result of long range interactions of the diffuse interface, charge effects and mechanical stresses were identified: i) diffusion limited population due to negligible composition gradients, ii) stress-induced population as a result of chemically induced stresses, and iii) lithiation-induced population, as a consequence of the electrochemical potential gradients.</p>

The Master thesis describe basic electrochemical processes in lithium-ion batteries and characteristic organic polar solvents for these articles. It focuses primarily on the aprotic liquid electrolytes for lithium-ion batteries and the subsequent use of gas chromatography to analyze the collected gas sample from the test article. For this experiment is, in this Master thesis, designed and described experimental arrangement in the form of a glass cell, which allows collection from the space above the working electrode. Finally, the work evaluates the effect of electrode potential on the stability of electrolytes in strongly positive potentials.

The search for alternate and renewable energy resources as well as the efficient use of energy and development of such systems that can help to save the energy consumption is needed because of exponential growth in world population, limited conventional fossil fuel resources, and to meet the increasing demand of clean and environment friendly substitutes. Hydrogen being the simplest, most abundant and clean energy carrier has the potential to fulfill some of these requirements provided the development of efficient, safe and durable systems for its production, storage and usage. Chemical hydrides, complex hydrides and nanomaterials, where the hydrogen is either chemically bonded to the metal ions or physiosorbed, are the possible means to overcome the difficulties associated with the storage and usage of hydrogen at favorable conditions. We have studied the structural and electronic properties of some of the chemical hydrides, complex hydrides and functionalized nanostructures to understand the kinetics and thermodynamics of these materials. Another active field relating to energy storage is rechargeable batteries. We have studied the detailed crystal and electronic structures of Li and Mg based cathode materials and calculated the average intercalation voltage of the corresponding batteries. We found that transition metal doped MgH2 nanocluster is a material to use efficiently not only in batteries but also in fuel-cell technologies. MAX phases can be used to develop the systems to save the energy consumption. We have chosen one compound from each of all known types of MAX phases and analyzed the structural, electronic, and mechanical properties using the hybrid functional. We suggest that the proper treatment of correlation effects is important for the correct description of Cr2AlC and Cr2GeC by the good choice of Hubbard 'U' in DFT+U method. Hydrogen is fascinating to physicists due to predicted possibility of metallization and high temperature superconductivity. On the basis of our ab initio molecular dynamics studies, we propose that the recent claim of conductive hydrogen by experiments might be explained by the diffusion of hydrogen at relevant pressure and temperature. In this thesis we also present the studies of phase change memory materials, oxides and amorphization of oxide materials, spintronics and sulfide materials.

Ce travail de thèse propose une méthodologie systématique d’évaluation et de comparaison des gains en émissions de CO2 de véhicules hybrides électriques de différentes architectures et intégrant différentes fonctionnalités. Une méthodologie de dimensionnement a été mise en place, elle se base sur la définition d’un cahier des charges en performances dynamiques des véhicules, la mise en place d’algorithmes de mise à l’échelle afin de générer les données des composants de la chaîne de traction (batterie, machine électrique, moteur thermique), et l’utilisation de procédures de dimensionnement du véhicule sous contrainte de minimisation des émissions de CO2. L’évaluation énergétique des différentes configurations de véhicule ainsi dimensionnées s’articule autour de la définition de différents usages du véhicule et sur l’implémentation d’une loi de gestion optimale de l’énergie de type Principe du Minimum de Pontriaguine. Ces méthodologies ont été appliquées à une architecture conventionnelle, servant de référence pour les performances dynamiques et les consommations énergétiques, et d’une architecture hybride parallèle pré-transmission, pour laquelle une configuration hybride rechargeable et une configuration hybride non rechargeable ont été implémentées. / This thesis work proposes a systematic methodology dedicated to the evaluation and comparison of CO2 emissions’ reduction for hybrid electric vehicles with different architectures and different levels of functionality. A sizing methodology has been developed, which is based on the definition of the requirements for the dynamic performances of vehicles, on the development of scaling algorithms in order to generate the dataset for the powertrain components (battery, electric motor, engine), and on the application of procedures for the sizing of a vehicle under CO2 emissions’ minimization constraint. The energy consumption evaluation of the different vehicle configurations, which were previously sized, is founded on the definition of a variety of vehicle’s type of use, as well as on the implementation of an optimal energy management strategy, the Pontryaguin’s Minimum Principle. These methodologies have been applied to a conventional vehicle architecture, which has been used as a reference for dynamic performances and energy consumption, and to a hybrid parallel pre-transmission architecture, which has been defined in two configurations, a plug-in hybrid and a non plug-in full-hybrid.

A galvanic cell converts chemical energy into electrical energy. Devices that carry out these conversions are called batteries. In batteries, generally the chemical components are contained within the device itself. If the reactants are supplied from an external source as they are consumed, the device is called a fuel cell. A fuel cell converts chemical energy into electrical energy as long as the chemicals are supplied from external reserves. The working principle of a metal-air battery involves the principles of both batteries and fuel cells. The anode of a metal-air cell is stored inside the cell, whereas O2 for the air-electrode is supplied from either atmosphere or a tank. There are several metal-air batteries available academically, which include Zn-air, Alair, Fe-air, Mg-air, Ca-air, Li-air and Na-air batteries. So far, only Zn-air battery is successfully commercialized. Li-air battery is attractive compared to other metal-air batteries because of its high theoretical energy density (11140 Wh kg-1). The energy density of Li-air battery is 3 - 5 times greater than state-of-art Li-ion battery. Li-air (or Li-O2) battery comprises Li-metal as the anode and a porous cathode. The cathode and the anode are separated by a suitable separator soaked in an organic electrolyte. Atmospheric air can enter the battery through the porous cathode. Out of the mixture of gases present in the air, only O2 is electrochemically active. For optimization purpose, most of researchers use pure O2 gas instead of air. Li-air battery is not commercialized till now because of several issues associated with it. The issues include: (i) sluggish kinetics of O2 electrode reaction, (ii) decomposition of the electrolyte during charge-discharge cycling, (iii) formation of Li dendrites, (iv) contamination by moisture, etc. Among these scientific and technical problems related to Li-O2 cell system, studies on rechargeable O2 electrode with fast kinetics of oxygen reduction reaction (ORR) during the cell discharge and oxygen evolution reaction (OER) during charge in non-aqueous electrolytes are important. In non-aqueous electrolytes, the 1-electron reduction of O2 to form superoxide (O2 -) is known to occur as the first step. (ii) Subsequently, superoxide undergoes reduction to peroxide (O2 2-) and then to oxide (O2-). The kinetics of ORR is slow in non-aqueous electrolytes. Furthermore, the reaction needs to be reversible for rechargeable Li-air batteries. In order to realize fast kinetics, a suitable catalyst is essential. The catalyst should be bifunctional for both of ORR and OER in rechargeable battery applications. Noble metal particles have been rarely investigated as catalysts for O2 electrode of Li-O2 cells. Graphene has two-dimensional planar structure with sp2 bonded carbon atoms. It has become an important electrode material owing to its high electronic conductivity and large surface area. It has been investigated for applications such as supercapacitors, Li-ion batteries, and fuel cells. Catalyst nanoparticles prepared and anchored to graphene sheets are expected to sustain discrete existence without undergoing agglomeration and therefore they possess a high catalytic stability for long term experiments as well as applications. In this context, it is intended to explore the catalytic activity of noble metal nanoparticles dispersed on reduced graphene oxide (RGO) for O2 electrode of Li-O2 cells. While a majority of the investigations reported in the thesis involves noble metal and alloy particles dispersed on RGO sheets, results on polypyrrole-RGO composite and also magnesium cobalt silicate for Li-O2 system are included. A chapter on electrochemical impedance analysis of LiMn2O4, a cathode material of Li-ion batteries, is also presented in the thesis. Introduction on electrochemical energy storage systems, in particular on Li-O2 system is provided in the 1st Chapter of the thesis. Synthesis of Ag nanoparticles anchored to RGO and catalytic activity are presented in the 2nd Chapter. Ag-RGO is prepared by insitu reduction of Ag+ ions and graphene oxide in aqueous phase by ethylene glycol as the reducing agent. The product is characterized by powder XRD, UV-VIS, IR, Raman, AFM, XPS, SEM and TEM studies. The SEM images show the layered morphology of graphene and TEM images confirm the presence of Ag nanoparticles of average diameter less than 5 nm anchored to RGO (Fig. 1a). Ag-RGO is investigated for ORR in alkaline (1 M KOH), neutral (1 M K2SO4) and non-aqueous 0.1 M tetrabutyl ammonium perchlorate in dimethyl sulphoxide (TBAP-DMSO) electrolytes. The ORR follows 4e- reduction in aqueous and 1e- reduction pathway in non-aqueous electrolytes. Li-O2 cells are assembled with Ag-RGO as (iii) Fig. 1. (a) TEM image of Ag-RGO and (b) charge-discharge voltage profiles of Li-O2 (Ag-RGO) cells. oxygen electrode catalyst in non-aqueous electrolyte (1 M LiPF6-DMSO) and subjected to charge-discharge cycling at several current densities. The discharge capacity values obtained are 11950 (11.29), 9340 (5.00), and 2780 mAh g-1 (2.47 mAh cm-2) when discharged at 0.2, 0.5, 0.8 mA cm-2, respectively (Fig. 1b). Powder XRD studies of discharged electrodes indicate the formation of Li2O2 and Li2O during the cell discharge. In addition to these studies, Na-O2 cells are also assembled with Ag-RGO in non-aqueous electrolyte. It is concluded that the chemistry Li-O2 and Na-O2 cells are similar except for the capacity values. Metal nanoparticles of Au, Pd and Ir are decorated on RGO sheets by reduction of metal ions on graphene oxide by NaBH4. Au-RGO, Pd-RGO and Ir-RGO are characterized by various physicochemical techniques. Particle size of metal nanoparticles ranges from 2 to Fig.2. Charge-discharge voltage profiles Li-O2(RGO) (i) and Li-O2(Au-RGO) (ii) cells at current density 0.3 mA cm-2. 0 2500 5000 7500 10000 12500 15000 10 nm on graphene sheets. All samples are studied for ORR in aqueous and non-aqueous electrolytes by cyclic voltammetry and rotating disk electrode experiments. Li-O2 cells are assembled in 1 M LiPF6-DMSO and discharge capacity values obtained are 3344, 8192 and 11449 mAh g-1 with Au-RGO, Pd-RGO and Ir-RGO, respectively, at 0.2 mA cm-2 current density. The results of these studies are described in Chapter 3. Synthesis and electrochemical activity of Pt-based alloy nanoparticles (Pt3Ni, Pt3Co and Pt3Fe) on RGO are presented in Chapter 4. The Pt3Ni alloy particles are prepared by simultaneous reduction of Pt4+, Ni2+ and graphene oxide by hydrazine in ethylene glycol medium. Pt3Co-RGO and Pt3Fe-RGO are also prepared similar to Pt3Ni-RGO. Formation of alloys is confirmed with XRD studies. O2 reduction reaction on Pt-alloys in non-aqueous electrolyte follows 1e- reduction to O2 -. RDE results show that Pt3Ni-RGO is a better catalyst than Pt for O2 reduction (Fig. 3). Li-O2 cells are assembled with all samples and subjected to Fig. 3. Linear sweep voltammograms of Pt3Ni-RGO, Pt3Co-RGO and Pt3Fe-RGO in 0.1 M TBAPDMSO with 1600 rpm at 10 mV s-1 scan rate. The area of GC electrode was 0.0314 cm2 with a catalyst mass of 200 μg. charge-discharge cycling at several current densities. The initial discharge capacity values obtained are 14128, 5000 and 10500 mAh g-1 with Pt3Ni-RGO, Pt3Co-RGO and Pt3Fe-RGO, respectively, as the air electrode catalysts. Polypyrrole (PPY) is an attractive conducting polymer with advantages such as high electronic conductivity and electrochemical stability. A combination of advantages of graphene and PPY composite are explained in the Chapter 5. PPY is grown on already synthesized RGO sheets by oxidative polymerization of pyrrole in an acidic PY composite is characterized by XRD and Raman spectroscopy studies. Li-O2 cells are assembled in non-aqueous electrolyte and subjected for charge-discharge cycling at different current densities. The discharge capacity value of Li-O2(PPY-RGO) cell is 3358 mAh g-1 Fig. 4. (a) Discharge-charge performance of Li-O2(PPY-RGO) cell with a current density of 0.2 mA cm-2 limiting to a capacity of 1000 mAh g-1 and (b) variation of cut-off voltages on cycling. (3.94 mAh cm-2) in the first cycle. Li-O2(PPY-RGO) cell delivers 3.7 times greater discharge capacity than Li-O2(RGO) cell. Cycling stability of Li-O2 (PPY-RGO) cell is investigated by charge-discharge cycling by limiting the capacity to 1000 mAh g-1, and the cell voltage at the end of discharge and at the end of charge are found constant at 2.75 and 4.10 V, respectively (Fig. 4 a, b). This study shows that PPY-RGO is stable in Li-O2 cells. Electrochemical impedance study shows that charge-transfer resistant is 500 Ω for freshly assembled Li- O2(PPY-RGO) cell and it decreases to 200 Ω after 1st discharge. Synthesis of magnesium cobalt silicate and its electrochemical activity are presented in Chapter 6. MgCoSiO4 is synthesized by mixed solvothermal approach and characterized by various physicochemical techniques. Cubic shaped MgCoSiO4 is investigated for oxygen evolution reaction (OER) activity in alkaline and neutral media. The current values at 0.95 versus SHE are 43, 0.18, 16 mA cm-2 on MgCoSiO4, bare carbon paper and Pt foil electrodes, respectively (Fig. 5), indicating that MgCoSiO4 is a good catalyst for OER. The onset potential for OER is 0.68 V versus SHE on MgCoSiO4 in 1 M KOH. OER activity on MgCoSiO4 is also studied in K2SO4 and phosphate buffer electrolytes. The results indicate good catalytic activity of MgCoSiO4 in neutral electrolytes also. The catalytic activity of Fig. 5. Cyclic voltammograms of bare carbon paper (i), Pt foil (ii), MgCoSiO4 coated carbon (iii) electrodes in 1 M KOH (sweep rate = 5 mV s-1, loading level = 1.15 mg, area = 0.5 cm-2). MgCoSiO4 towards ORR in aqueous and non-aqueous electrolytes is studied by RDE experiments. Li-O2 cells are assembled with bifunctional MgCoSiO4 catalyst in 1 M LiPF6- DMSO electrolyte and the discharge capacity values obtained are 7721 (8.27), 2510 (1.66) and 1053 mAh g-1 (0.92 mAh cm-2) when discharged at 0.3, 0.5 and 0.8 mA cm-2 current densities, respectively. Electrochemical impedance spectroscopy (EIS) measurements of LiMn2O4 electrode are carried out at different temperatures from -10 to 50 0C and in the potential range from 3.50 to 4.30 V, and the data are analysed in Chapter 7. In the EIS spectra recorded over the frequency range from 100 kHz to 0.01 Hz at different temperatures, there are two semicircles present in the Nyquist plot (Fig. 6a). But in 3.90 to 4.10 V versus Li/Li+(1M) potential range at low temperatures (-10 to 15 oC) range, another semicircle also appears (Fig. 6b). Impedance parameters such as solution resistant (Rs), charge-transfer resistance (Rct), doublelayer capacitance (Cdl), electronic resistance (Re) and Warburg impedance (WR), etc., are obtained by analysis of the EIS data. The variations of resistances with temperature are analysed by Arrhenius-like relationships and the apparent activation energies of the corresponding transport properties are evaluated. The values of activation energy for chargetransfer process are 0.37, 0.30 and 0.42 eV, at 3.50, 3.90 and 4.10 V versus Li/Li+(1M), respectively. The chemical diffusion coefficient of Li+ ions into LiMn2O4 calculated from EIS data. The values of diffusion coefficient calculated are in the range of 2.50 x 10-12 - 4.10 Fig. 6. Nyquist plot of impedance study of Li/LiMn2O4 cell at 3.50 V (a) and 3.90 V (b) at -10 0C. Details of the above studies are described in the thesis.

Subsequent to the studies on precursor lead-acid systems by Daniel, Grove and Sindesten, practical lead-acid batteries began with the research and inventions of Raymond Gaston Planté in France as early as in 1859, and, even to-day, lead-acid battery remains the most successful battery system ever developed, and no other battery is yet able to compete with lead-acid batteries on cost grounds, albeit batteries based on other chemistries are rapidly catching up. In the past, although lead-acid battery designs have been optimized in several different directions, there are still certain new challenges facing the lead-acid battery designers as additional failure modes become evident in various use modes. There are three types of lead-acid batteries in common use: (a) batteries with flooded or excess electrolyte, (b) low-maintenance lead-acid batteries with a large excess of electrolyte, and (c) batteries with immobilized electrolyte and a pressure-sensitive valve usually referred to as absorptive glass-microfibre (AGM) valve-regulated lead-acid (VRLA) batteries. The flooded-electrolyte lead-acid battery requires checking of specific gravity of electrolyte, periodic addition of water to maintain electrolyte level above the plates and recharge soon after discharge to prevent hard sulfation that causes loss of capacity. The emission of acid fumes corrodes metallic parts in the vicinity of the battery, and the seepage of acid on the top cover of the batteries leads to leakage current resulting in increased self-discharge and ground-shunt hazards. To overcome these problems, AGMVRLA batteries based on oxygen-recombination cycle have emerged. These batteries offer the freedom of battery placement, cyclability without the addition of water or checking the specific gravity, increased safety, and superior performance in some instances. Both flooded-electrolyte and AGM-VRLA batteries can suffer from acid stratification. But, AGM-VRLA batteries are especially susceptible to failures owing to the heat generated by oxygen recombination within the cells as well as due to cell-to-cell variations in electrolyte volumes. Indeed, partial heating of AGM-VRLA batteries could cause dry-out with grid corrosion and even lead to thermal runaway. Consequently, mitigating temperature variations in AGM-VRLA batteries becomes seminal to their commercial success. A dissipation of local heat within the AGM-VRLA batteries can be achieved by adequately filling the void volume in the battery with a thermally conducting gel, such as a gel formed from colloidal silica and sulfuric-acid electrolyte. Although, conventional lead-acid batteries are considered rather a matured technology, significant research and development efforts are currently under way to enhance their performance. Indeed, many improvements have been made in the lead-acid battery since its invention, and although the essential electrochemistry remains unchanged, the modern lead-acid batteries have little semblance to those produced 50 years ago. Over the years, seminal advances have been made in the lead-alloys used, in the materials and design of separators, in battery packaging and in their construction methods, which have led to lead-acid batteries with improved performance, lighter weight and lower cost. This thesis is an attempt to develop lightweight hybrid-VRLA batteries.

The Master´s thesis describes continuous automatic train protection system and its functional properties, principally the transmission of special encoded signal between stationary part and rail vehicle. There is also summarized some important information about the gear rotational speed sensors and its communication with other onboard peripherals. Depends by analysed parameters of electrical signals, the general suggestion of portable electronic device is outlined. Portable electronic device or TESTER will be used to in phase of testing mobile part of automatic train protection system mounted onboard of rail vehicle. Tester will generate equivalent electrical signals to signals in system automatic train protection and the real system response will be possible to evaluate. The generator block allows to model real electrical signals in automatic train protection technology type LS or type EVM and signals rail vehicle odometry.

The focus of the work is the calculation and design of battery-powered drive of locomotive, operating in the sub-siding mode, ie when the locomotive is moving on the track section without the overhead line. The proposed battery groups to ensure the drive train will be installed directly into the locomotive engine room. In the theoretical part of the work there has been done the analysis of the electrical locomotives and electrical unit, which nowadays are used in the Czech Republic in driving of voltage controller with the integrated circuit. Then, in the chapter there is a brief description modern locomotives frequency convertor’s and rectifier’s function. The practical part of the work contains the necessary force and energy calculation for train moving on the determined rails. On the base of the received data, the design of battery groups has been done. These battery groups will work as an independent traction which insures the moving of the train on the determined rails. In the work the design, which consists of STEP-UP and STEP-DOWN convertors, has also been done. The power model and model management were created in Matlab Simulink programme. Data and graphs exported from the Matlab Simulink programm are determined for verifying convertor’s function, which can be found in a separate chapter. In addition to the proposal of the battery drive is at work also has been calculated loss of traction rectifier during normal operation of the locomotive, ie outside siding mode. For this calculation, in the conclusion is listed the theory of calculation of the losses incipient in the transistor and freewheeling diode of rectifier. According to the theory own calculation is performed. Subsequently the liquid cooler calculation of the rectifier is calculated.

Mit der Entwicklung der Weltwirtschaft steigt der Energieverbrauch weiterhin stark an. Darüber hinaus reduzieren sich die nicht erneuerbaren Energiequellen, wie Öl, Erdgas und Kohle und die Umweltverschmutzung wird größer. Daher soll die Energienutzung in eine neue, erneuerbare und umweltfreundliche Richtung gehen. Die Arbeit hat zum Ziel innovative, wässrige Akkumulatoren zu entwickeln. Im Allgemeinen können wässrige Akkumulatoren gemäß der Elektrolyte in drei verschiedenen Kategorien eingeteilt werden. Es gibt feste, organische und wässrige Elektrolyte einschließlich saurer, alkalischer und neutraler. In Bezug auf metallbasierte negative Elektroden können sie auch als Lithiumbatterie, Natriumbatterie sowie Magnesiumbatterie etc. bezeichnet werden. Daher werden im ersten Kapitel einige typische Akkumulatoren, wie die Lithiumionenbatterien, Daniell-Element, Weston-Zelle, Nickel-Cadmium-Batterie und Bleibatterie vorgestellt. Im Vergleich zu organischen Elektrolyten wurden wässrige Akkumulatoren aufgrund ihrer billigen, leichten und sicheren Bauweise in den letzten Jahren umfassend untersucht. Zusätzlich dazu ist die ionische Leitfähigkeit von wässrigen Elektrolyten um zwei Größenordnungen höher als die von organischen Elektrolyten. Dies garantiert eine hohe Entladungsrate für wässrige wiederaufladbare Batterien. Somit bieten wiederaufladbare Batterien potentielle Anwendungen in der Energiespeicherung und -umwandlung. Allerdings verursachen starke Säuren oder Basen, die als Elektrolyte für sekundäre Batterien eingesetzt werden, eine starke Korrosion. Somit wären neutrale wässrige Elektrolyten (oder Elektrolytlösungen) mit einem pH-Wert in der Nähe von sieben, wie zum Beispiel schwach basisch oder sauer, die beste Wahl für wässrige Akkumulatoren. Aktive Elektrodenmaterialien der Batterien, die hochgiftige Schwermetalle wie Blei, Quecksilber und Cadmium enthalten, belasten die Umwelt. Um die Menge an Schwermetallen und Säure (oder Basen) zu verringern, sowie die spezifische Kapazität von Batterien zu erhöhen, untersucht diese Dissertation vor allem die elektrochemische Leistung der PbSO4/0,5M Li2SO4/LiMn2O4-Zelle, der Cd/0,5M Li2SO4+10mM Cd(Ac)2/LiCoO2-Zelle und von C/Cu/CNT-Gemischen als negative Materialien in 0,5 M K2CO3–Elektrolyt-Halbzellen. Die zugehörigen experimentellen Ergebnisse werden wie folgt zusammengefaßt: Im Kapitel 3 wurde eine säurefreie Bleibatterie auf Basis des LiMn2O4-Spinells als positive Elektrode, PbSO4 als negativer Elektrode und der wässrigen Lösung von 0,5 M Li2SO4 als Elektrolyt zusammengesetzt. Die spezifische Kapazität auf Basis von LiMn2O4 beträgt 128 mA•h•g-1 und die durchschnittliche Entladungsspannung beträgt 1,3 V. Die berechnete Energiedichte ist 68 W•h•kg-1, bezogen auf die praktischen Kapazitäten der beiden Elektroden. Diese Ergebnisse zeigen, dass die positive Elektrode der Bleibatterie (PbO2) vollständig durch umweltfreundliches und billiges LiMn2O4 ersetzt werden kann, wodurch 50 % des Bleis eingespart werden können. Außerdem wird Schwefelsäure nicht benötigt. Kapitel 4 zeigt eine wässrige wiederaufladbare Lithiumionenbatterie, die metallisches Cadmium als negative Elektrode, LiCoO2-Nanopartikel als positive Elektrode und eine wässrige, neutrale Lösung von 0,5 M Li2SO4 und 10 mM Cd(Ac)2 als Elektrolyt enthält. Die durchschnittliche Entladungsspannung beträgt 1,2 V und die spezifische Entladungskapazität beträgt 107 mA•h•g-1 auf Basis von LiCoO2. Die berechnete Energiedichte beträgt 72 W•h•kg-1, bezogen auf die praktischen Kapazitäten der beiden Elektroden. Wie bereits oben beschrieben demonstrieren die Ergebnisse, dass 100 % von Quecksilber und der alkalischen Elektrolyt im Vergleich zur Weston-Zelle bzw. der Ni-Cd-Batterie, eingespart werden können. Kapitel 5 zeigt einen Verbundwerkstoff von Kupfer, das auf der Oberfläche von CNTs durch eine Redoxreaktion zwischen Kupferacetat und Ethylenglykol, zur Verwendung als negative Elektrode bei hohen Strömen in der Energiespeicherung, hergestellt wurde. Der so hergestellte C/Cu/CNT-Verbundwerkstoff zeigt ein besseres Geschwindigkeitsverhalten und eine höhere Kapazität ebenso wie eine exzellente Zyklusstabilität in wässrigen 0,5 M K2CO3-Lösungen im Vergleich zu einfachem Kupfer. Die Kohlenstoffbeschichtung kann die Auflösung von Kupfercarbonatkomplexen verhindern, die Elektrodenleitfähigkeit erhöhen und die Oberflächenchemie des aktiven Materials verbessern. / With the economic development of the world, energy consumption continues to rise sharply. Moreover, non-renewable energy sources including fossil oil, natural gas and coal are declining gradually and environmental pollution is becoming more severe. Hence, energy usage should go into a new direction of development that is renewable and environmental-friendly. This thesis aims to explore innovative aqueous rechargeable batteries. Generally, rechargeable batteries could be classified into three categories according to the different electrolytes. There are solid electrolytes, organic electrolytes and aqueous electrolytes including acidic, alkaline and neutral. In terms of metal-based negative electrodes, they also could be named lithium battery, sodium battery as well as magnesium battery etc. Therefore, some typical rechargeable batteries are introduced in Chapter 1, such as lithium ion batteries, Daniell-type cell, Weston cell, Ni-Cd battery and lead-acid battery. Compared to organic electrolytes, aqueous rechargeable batteries have been investigated broadly in recent years because they are inexpensive, easy to construct and safe. Additionally, the ionic conductivity of aqueous electrolytes is higher than that of organic electrolytes by about two orders of magnitude. Furthermore, it ensures high rate capability for aqueous rechargeable battery. Consequently, aqueous rechargeable batteries present potential applications in energy storage and conversion. However, strong acid or alkaline, which is used as the electrolyte for secondary batteries, will cause serious corrosion. Thus, neutral aqueous electrolyte (or pH value of electrolyte solution close to 7 such as weak alkaline and acid) would be the best choice for aqueous rechargeable battery. In addition, the electrode active materials of batteries containing highly toxic heavy metals such as Pb, Hg and Cd, pollute the environment. As a result, in order to reduce the amount of heavy metals and acid (or alkaline) as well as increase the specific capacity of batteries, this dissertation mainly studies the electrochemical performance of PbSO4/0.5M Li2SO4/LiMn2O4 full battery, Cd/0.5M Li2SO4+10 mM Cd(Ac)2/LiCoO2 full battery and C/Cu/CNT composites as negative material in 0.5 M K2CO3 electrolyte as half cell. The related experimental results are as follows: In Chapter 3, an acid-free lead battery was assembled based on spinel LiMn2O4 as the positive electrode, PbSO4 as the negative electrode, and 0.5 M Li2SO4 aqueous solution as the electrolyte. Its specific capacity based on the LiMn2O4 is 128 mA•h•g-1 and the average discharge voltage is 1.3 V. The calculated energy density is 68 W•h•kg-1 based on the practical capacities of the two electrodes. These results show that the positive electrode of the lead acid battery (PbO2) can be totally replaced by the environmentally friendly and cheap LiMn2O4, which implies that 50 % of Pb can be saved. In addition, H2SO4 is not needed. Chapter 4 shows an aqueous rechargeable lithium ion battery using metallic Cd as the negative electrode, LiCoO2 nanoparticles as the positive electrode, and an aqueous neutral solution of 0.5 M Li2SO4 and 10 mM Cd(Ac)2 as the electrolyte. Its average discharge voltage is 1.2 V and the specific discharge capacity is 107 mA•h•g-1 based on the LiCoO2 . In addition, the calculated energy density based on the capacities of the electrodes is 72 W•h•kg-1. As described above, the results demonstrate that 100 % of Hg and alkaline electrolyte can be saved compared with the Weston cell and the Ni-Cd battery, respectively. The work reported in Chapter 5 deals with a composite of copper grown on the surface of CNTs as prepared by a redox reaction between copper acetate and ethylene glycol for use as negative electrode at high currents in energy storage. The as-prepared C/Cu/CNTs composite exhibits better rate behavior and higher capacity as well as excellent cycling stability in aqueous 0.5 M K2CO3 solution compared to the unsupported copper. The carbon coating can effectively prevent the dissolution of copper carbonate complexes, increase the electrode conductivity, improve the surface chemistry of the active material and protect the electrode from direct contact with electrolyte solution.