Myrvold, Journal of Power Sources If the violations are within tolerable limits can be tested with the Hilbert or Kramers-Kronig transform []. This thesis examines the optimal combination of different operation modes and the associated design considerations. The interpretation of the series resistance at the intersection of the real axis is similar to that of the negative electrode. Penazzi, Electrochimica Acta 30 6

Shortly thereafter, in the same year, he was appointed Professor at the Cologne University of Applied Science. He started by obtaining a degree as technician in Points that do not pass Kramers-Kronig consistency check are not shown. Course of reaction during discharge as in Fig. Acid concentration changes with SOC, so this is the most probable explanation for this semicircle.

Aachener Beitr├Ąge des ISEA

In the second part of this paper, deformation of the spectra due to concentration limitation is investigated. The beginning of a large semicircle is observable at frequencies below 10 Hz.

From tillhe worked at the Philips Research Center in Aachen. If the violations are within tolerable limits can be tested with the Hilbert or Kramers-Kronig transform [].

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Sadkowski, Electrochimica Acta 49 14 Negative electrode As described in Section 2. Ultimately, the concept enhances the suitability of 3ph-DAB converters for a wider range of applications. In summary, the proposed operation concept offers the possibility to achieve high efficiencies for a wide voltage and power range. Takenouti, Journal of Applied Electrochemistry 7 However, the topology is known to suffer from reduced This includes testing and characterisation of battery cells and battery packs with a capacity of more than test benches, development of online diagnosis algorithms of batteries, and battery and energy management systems including hardware platformsinvestigation of ageing processes and modelling of the dynamic performance of batteries, and prognosis of lifetime and electrical performance of batteries in applications based on post-mortem analysis.


Dirk Uwe Sauer – Editor-in-Chief – Journal of Energy Storage

All semicircles must be connected with the processes connected to the electrode reactions. The negative sign here is needed for the negative electrode; for a positive electrode, the sign is inverted.

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As a scientist, and from onwards as the head of two groups, he worked on energy storage systems, decentralised power generators and storage systems in grids, and on off-grid power supply systems ranging from few W to MW systems.

Measured frequencies are between 6 kHz and 3 mHz with eight frequencies per decade. Gobal, Journal of Power Sources 17 To send an email to Dirk Uwe Sauer please complete the short form below.

Hence, if A rj DC is negative, the lower-frequency semicircle is inductive and if it is positive, the semicircle is capacitive.

This includes concepts and consequence of a CO2-free energy supply, concepts for the integration of electric vehicles, central and decentralised storage systems into the grid, and the design and development of battery packs and grid-connected battery storage systems with a power of up to several MW.


Leek, Surface Technology 13 Doncker, Journal of Power Sources 85 1 This is illustrated in the following with two exemplary sets of parameters.

Macdonald, Electrochimica Acta 35 10 Step 3 is the chemical sulphation reaction, which is not directly visible in the impedance spectra, only if concentration limitation becomes significant. It is generally agreed that the origin of the inductive branch is the geometry of the cell, see e.

Inductive semicircles are indicated.

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The lead-acid tgesis has a limited Heinz was also a personal friend to many of us. Navigation Academics Research The Institute. In the Proc. Besides this inductive branch, the negative electrode shows a so-called inductive semicircle at low frequencies about 10 mHz and below and the positive electrode sometimes shows an inductive semicircle at frequencies higher than the intersection point with the real axis between 10 Hz and some Hz.

Taylor, Journal of Electroanalytical Chemistry 27 Several authors have mentioned that adsorption of different ions takes place at the negative electrode [].

Spinelli, Journal of Power Sources 85 1 Sometimes a small inductive semi circle is observable in the range from 10 Hz to Hz Fig. However, the inductive semicircle is too small in the simulation compared to the measurements.