TU Berlin

Electrical Energy Storage TechnologyChair

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Prof. Dr.-Ing. Julia Kowal

Julia Kowal

Room: EMH 163


Einsteinufer 11

Sec. EMH 2

10587 Berlin

Phone: +49 (0)30 314-25394

Fax:     +49 (0)30 314-21133


Consultation hours: On Mondays 9 - 10 h and on appointment. In summer semester 2022 (25.4.-18.7.), the consultation hour will be from 10-11 h.

In most weeks, I am in the office on mondays, so a personal meeting is possible again. To be sure, please ask before you come. Alternatively, you can phone me or we can arrange a Zoom meeting.


since 03/2014
Chair of Electrical Energy Storage Technology at the TU Berlin
01/10 - 02/14
Senior engineer at the department of Electrochemical Energy Conversion and Storage Systems, ISEA, RWTH Aachen
PhD at RWTH Aachen, Topic: "Spatially-resolved impedance of nonlinear inhomogeneous devices - using the example of the lead-acid battery"
Visiting researcher at the company Exide in Azuqueca de Hénares, Spain
Visiting Researcher at the research centre RISØ in Roskilde, Denmark
Research assistant at the department of Electrochemical Energy Storage Conversion and Systems at the Institute For Power Electronics and Electrical Drives (ISEA), RWTH Aachen
Studies of electrical engineering at RWTH Aachen Diploma thesis: "Investigation of the thermal behaviour of electrochemical energy storage systems in vehicle on-board power supplies"



Awards and Scholarships
Herbert-Kind-Price of ETG in the VDE
Brigitte-Berkenhoff-Price for the best graduate in the field of electrical engineering at RWTH Aachen
Aachen's VDE price
Sponsorship through the Prof. Dr. Koepchen Merit Foundation (RWE)


Comparison of Dynamic Charge Acceptance Tests on Lead-Acid Cells for Carbon Additive Screening
Citation key https://doi.org/10.1002/ente.202101051
Author Bozkaya, Begüm and Bauknecht, Sophia and Settelein, Jochen and Kowal, Julia and Karden, Eckhard and Giffin, Guinevere A.
Pages 2101051
Year 2022
DOI https://doi.org/10.1002/ente.202101051
Journal Energy Technology
Volume n/a
Number n/a
Abstract Including a certain amount of carbon in the negative active material is currently the state-of-the-art method to improve the dynamic charge acceptance (DCA) of lead-acid batteries. The DCA is a key parameter of batteries used in micro-hybrid cars where brake energy recuperation is implemented. To find the optimal carbon additive, it is essential to test the carbon both in short-term and long-term tests. This work investigates the long-term and short-term DCA of 2 V, 2.5 Ah lead-acid cells and correlates the results with the external surface area of the carbon. Five different carbons with tailored particle size (27 nm – 633 nm) and external surface area (7.1 m2 g-1 – 159.3 m2 g-1) were employed as additives in the negative electrodes. The charge acceptance of cells according to the charge acceptance test 2 (SBA), the DCA (EN) test and the Run-in DCA test (Ford) is increased via an increase in the carbon external surface area. A correlation between the short-term tests and the first weeks of the Run-in DCA test is established for the carbon impact. After several weeks of Run-in DCA test, the carbon effect is diminished and only a differentiation between high and low DCA cells is possible. This article is protected by copyright. All rights reserved.
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