Helmut Ehrenberg Principal Research interests

Helmut Ehrenberg
Full Professor (W3), Inorganic Chemistry. Born
1966; Diploma 1991 in Physics, Technische
Hochschule Darmstadt; Doctoral Degree 1996 TU
Darmstadt in Materials Science; Marie-Curie Postdoctoral Fellow 1997-99 University of Cambridge,
UK; Habilitation 2005, TU Darmstadt; Head of
Department 2006-2010, IFW Dresden, Head of the
Institute for Applied Materials-Energy Storage
Systems (IAM-ESS) since 2012.
Phone: +49 721 608 47915, Fax: +49 721 608
E-Mail: [email protected]
between the different components in a full
operational device. Studies are therefore
performed from the macroscopic length
scale of a device down to surface analysis
and nanodomain regions.
Focus (II) is based on a strong crystallographic background and correlates the underlying crystal structures with resulting
properties. Different polymorphs and
phase transitions, induced by high pressure, temperature or external magnetic and
electric fields are considered to elucidate
the effects of structural changes on the
performance of materials. Dedicated setups
have been developed for in situ diffraction
experiments in external fields. Transitionmetal oxides are in the centre of interest,
but intermetallic compounds and composite materials are also investigated in detail.
Principal Research interests
Two main aspects are in the focus of research: (I) Materials for energy storage,
studied at the full electrochemical cell level. (II) Structure-property relationships for
functional materials, including magnetic
properties, transport behaviour and piezoelectric response.
Focus (I) addresses the development of
new battery materials, the characterization
of electrochemical and structural properties as well as the elucidation of the fundamental mechanisms involved in storing
energy. To accomplish that, enhanced and
dedicated in operando characterization
techniques are developed, using synchrotron and neutron radiation. New energy
storage concepts like functional composites and beyond Li-ion batteries are also
considered, like Mg-ion based batteries,
Li-oxygen batteries and Redox-Flow batteries. Particular attention is given to the
life time of energy storage devices and the
relevant degradation mechanisms. This
requires bridging the gap between fundamental research on model systems to reveal individual processes and the full complexity of functional composite materials
with very strong materials interactions
Scheme of a hybrid cathode, based on an ordered array of
carbon nanofilaments (CNF) coated with LiCoPO4 (left),
individual coated CNF (middle) and a brush of coated
CNFs (right), see [5] for details.
Selected publications
1. „Understanding structural changes in NMC Liion cells by in situ neutron diffraction.“ O.
Dolotko, A. Senyshyn, M.J. Mühlbauer, K.
Nikolowski, H. Ehrenberg J. Power Sources
2014, 255, 197–203.
2. “Binary Lithium Indides Li22–xIn8+x (x = 0.1),
Li11–xIn4+x (x = 1.05), and Li10–xIn2+x (x = 1.59)
with Clusters.” I. Chumak, V. Pavlyuk, H. Ehrenberg Eur. J. Inorg. Chem. 2014, 2053–2064.
3. „LiZn4-x (x = 0.825) as a (3 + 1)-dimensional
modulated derivative of hexagonal close packing.“ V Pavlyuk, I. Chumak, L. Akselrud, S.
Lidin, H. Ehrenberg Acta Cryst. 2014, B70,
4. “Advances in in situ powder diffraction of battery materials: a case study of the new beamline
P02.1 at DESY, Hamburg” M. Herklotz, F.
Scheiba, M. Hinterstein, K. Nikolowski, M.
Knapp, A.-C. Dippel, L. Giebeler, J. Eckert, H.
Ehrenberg J. Appl. Cryst. 2013, 46, 1117-1127.
5. “Disordered carbon nanofibers/LiCoPO4 composites as cathode materials for lithium ion batteries” A. Sarapulova, D. Mikhailova, L. A.
Schmitt, S. Oswald, N. Bramnik, H. Ehrenberg,
J. Sol-Gel Sci. Technol. 2012, 62, 98–110.