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Design of a measurement circuit for electrochemical cells cycling in SEM chamber
Tran, Quoc Bao ; Trochta, David (referee) ; Klvač, Ondřej (advisor)
This diploma thesis deals with the design of a measurement circuit consisting of two separate modules for measuring electric current in the order of nanoamperes (nA) for the in-situ analysis of lithium-ion cells in microscopic dimensions. The aim of this thesis is to build a prototype measurement circuit to solve the electromagnetic interference (EMI) problems associated with in-situ analysis and to perform subsequent testing of this circuit or modules. The diploma thesis is divided into two parts, namely a theoretical and an experimental part. In the theoretical part, research on electrochemical cells is described, where the focus is directed towards lithium-ion cells. The principle of the function of these cells is described and research on their degradation mechanisms has also been carried out. Furthermore, the testing methods of lithium-ion cells such as GCPL, OCV and CV have been described. In the theoretical part, the in-situ experiments already performed at Thermo Fisher Scientific Brno are described. One experiment consisted of assembling an electrochemical cell on a MEMS chip and the other experiment was performed using a micromanipulator as a current collector. Measured data were affected by electromagnetic interference. The practical part discusses the design of a measurement circuit that would theoretically solve the problems of measuring very small currents from an EMI perspective. It also describes how the measurement circuit was tested.
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Measurement and recording of the initial magnetization curve and hysteresis curve of ferromagnetic materials
Tran, Quoc Bao ; Vaněk, Jiří (referee) ; Klvač, Ondřej (advisor)
This thesis deals with the measurement of primary magnetization curves and hysteresis loop. The thesis is divided into two parts, the theoretical part and the practical part. The theoretical part describes the creation of magnetic field in materials, excitation of magnetic field by electric current or excitation of electric current by changing magnetic field. The practical part is focused on designing, construction and testing of amplifier and the measurement and displaying of hysteresis loop. In the end of the thesis is summarized what results were achieved.
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Measurement and recording of the initial magnetization curve and hysteresis curve of ferromagnetic materials
Tran, Quoc Bao ; Vaněk, Jiří (referee) ; Klvač, Ondřej (advisor)
This thesis deals with the measurement of primary magnetization curves and hysteresis loop. The thesis is divided into two parts, the theoretical part and the practical part. The theoretical part describes the creation of magnetic field in materials, excitation of magnetic field by electric current or excitation of electric current by changing magnetic field. The practical part is focused on designing, construction and testing of amplifier and the measurement and displaying of hysteresis loop. In the end of the thesis is summarized what results were achieved.
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