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Visar resultat 1 - 5 av 55 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Transient electrochemical methods for investigation of porous battery electrodes

    Författare :Anton Lundqvist; KTH; []
    Nyckelord :electrochemical iimpedance spectroscopy; limn2o4; mathematical modelling; metal hydride; mcroelectrode; porous electrode; potential step; state of charge;

    Sammanfattning : This thesis treats electrochemical methods used to studybattery materials. Two different types of materials are used asmodel systems in this study, metal hydride alloys used in thenickel-metal hydride battery and LiMn2O4suggested for use in the lithium-ion battery. Thetwo model systems are used to critically analyse differentexperimental methods. LÄS MER

  3. 2. Investigation of electrochemical properties and performance of stimulation/sensing electrodes for pacemaker applications

    Författare :Anna Norlin; Jinshan Pan; Dieter Scharnweber; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; pacemaker electrode; interfacial property; biomaterial; electrostimulation charge transfer mechanism; electrochemical impedance spectroscopy; transient processes; plasma electrolysis anodisation; porous niobium oxide; ruthenium oxide; nano-porous carbon; iridium oxide; titanium nitride; platinum; surface roughness; porous electrode; pacing impedance; electrode polarisation; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi;

    Sammanfattning : People suffering from certain types of arrhythmia may benefit from the implantation of a cardiac pacemaker. Pacemakers artificially stimulate the heart by applying short electrical pulses to the cardiac tissue to restore and maintain a steady heart rhythm. By adjusting the pulse delivery rate the heart is stimulated to beat at desired pace. LÄS MER

  4. 3. From Current Collectors to Electrodes : Aluminium Rod Structures for Three-dimensional Li-ion Micro-battery Applications

    Författare :Gabriel Oltean; Kristina Edström; Leif Nyholm; Erik Kelder; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 3D micro-batteries; aluminium; titanium oxide; current collectros; negative electrodes; electrodepostion; electrophoretic depostion; sol-gel synthesis;

    Sammanfattning : The potential use of 3D aluminium nanorod structures as current collectors and negative electrodes for 3D Li-ion micro-batteries was studied based on the use of relatively simple and cost-effective electrochemical and sol-gel deposition techniques.Aluminium rod structures were synthesised by galvanostatic electrodeposition using commercial porous membranes as templates. LÄS MER

  5. 4. Mechanical behavior of Lithium-ion battery electrodes – experimental and statistical finite element analyses

    Författare :İbrahim Buğra Üçel; Peter Gudmundson; Ralf Jänicke; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Li-ion batteries; mechanical testing; statistics; finite elements; electrodes; Solid Mechanics; Hållfasthetslära;

    Sammanfattning : The applications of Li-ion batteries in the electronics and vehicle industry is increasing at a very rapid pace. This is primarily due to superior properties such as high specific energy storage and power as well as wider operation temperature ranges. LÄS MER

  7. 5. Electrochemical characterisation of porous cathodes in the polymer electrolyte fuel cell

    Författare :Frédéric Jaouen; KTH; []
    Nyckelord :polymer electrolyte fuel cell; cathode; mass transport; porous electrode; modelling; agglomerate model; electrochemical impedance spectroscopy; current interrupt; transient techniques; non-noble catalysts;

    Sammanfattning : Polymer electrolyte fuel cells (PEFC) convert chemicalenergy into electrical energy with higher efficiency thaninternal combustion engines. They are particularly suited fortransportation applications or portable devices owing to theirhigh power density and low operating temperature. LÄS MER