Unconventional energy storage systems

Energy storage systems consist of matching devices for charging and discharging and the energy carrier. In principle all energy carriers (mechanical, electric, thermal, chemical) can be recycled, but the process differ greatly in complexity and efficiency. Storage cycles with high energy density materials show low efficiencies and vice versa. Grid-connected PV systems can use the storage capacity of the utility network and there is no need for additional energy storage in the near future. Stand-alone PV systems require energy storage systems but up to now there is no system available for long-term storage. It may be expected, that hydrogen systems will be on the market within the next few years. (ISE

Wasserstofftechnologie - Eine Übersicht

Übersicht über die Verfahren zur Herstellung, Speicherung und Nutzung von Wasserstoff. Der Einsatz von Wasserstoff als Energiespeicher in autarken Häusern wird erläutert

Polymerelektrolyt-Membran-Brennstoffzelle

The invention relates to a PEM fuel cell, consisting of at least one strip diaphragm (8) which consists of at least 2, maximum 10,000 flat individual cells each comprising an electrode layer (10-12, 13-15) applied on both sides of a diaphragm made of polymer fixed electrolytes, whereby the individual cells are switched in series and are made of non-conducting material plates (21, 22) which act as heat exchangers and fuel supply device, which are contacted on the strip diaphragm (8, 16) on both sides and separate conductive structures (23,24) routed externally to the voltage tap

PRECIPITATION PHENOMENA IN HEAVILY DOPED AgCl : Cd2+-CRYSTALS

Nous avons étudié le mécanisme de la précipitation dans les cristaux de chlorure d'argent fortement dopés avec Cd2+ utilisant quatre méthodes différentes : conductivité ionique (IC) thermocourant de dépolarisation (ITC), diffusion des rayons X aux petits angles (SAXS) et diffusion de la lumière. Pour contrôler nos méthodes nous avons exécuté des mesures IC et ITC, utilisant aussi des cristaux dopés avec Cd2+ au-dessous de la limite de solubilité. Les résultats sont en accord avec ceux trouvés dans la littérature. Par des mesures de IC et ITC nous avons trouvé que, dans les cristaux fortement dopés, les particules précipitantes peuvent injecter (accepter) des lacunes d'argent (Ag-) dans le réseau entourant. Evaluant les résultats de SAXS et de la diffusion de la lumière nous proposons le modèle suivant pour le mécanisme de la précipitation dans les cristaux fortement dopés : Les particules précipitantes sont composées d'un coeur de la phase CdCl2, entouré d'une couche composée de dipôles [Cd2+-Ag-]. L'existence d'une telle couche peut expliquer les résultats obtenus par les mesures IC et ITC.Ionic conductivity-, ITC-, small angle X-ray scattering-, and light scattering measurements were carried out to study precipitation phenomena in heavily doped AgCl : Cd2+ crystals. For ionic conductivity- and ITC-measurements we additionally used crystals with low doping concentrations to check our methods ; the resulting values for activation enthalpies were in good accordance with those in the literature. From the ionic conductivity- and ITC-measurements we conclude that the precipitated particles in the heavily doped crystals may inject Ag+-vacancies into the matrix thus ionizing themselves. In this way, the particles act as sinks or traps for Ag+-vacancies. From small angle X-ray measurements, confirmed by light scattering experiments a model is deduced for the mechanism of precipitation in the supersaturated crystal. In this model, the finall precipitated particle consists of a core of CdCl2 surrounded by a shell of Cd2+-Ag+-vacancy dipoles. Such a shell would give an understanding of the results obtained by ionic conductivity and ITC-measurements