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Prof. Dr. Philipp Adelhelm

Adelhelm, Philipp
Foto: Annegret Günther / FSU Jena

Prof. Dr. Philipp Adelhelm

Philipp Adelhelm (geb. 1978 in Waiblingen) studierte Werkstoffwissenschaften an der Universität Stuttgart / Max-Planck-Institut für Metallforschung mit Auslandsaufenthalten in Auckland (Neuseeland) und Stockholm (Schweden). Von 2005 bis 2007 arbeitete er am Max-Planck-Institut für Kolloid- und Grenzflächenforschung in Potsdam (Prof. Antonietti, Prof. Smarsly) auf dem Forschungsgebiet "poröse Kohlenstoffmaterialien" und wurde dort 2007 an der Universität in physikalischer Chemie promoviert. Es folgten zwei Jahre als Postdoktorand am Debye Institute for Nanomaterials Science (Group of Inorganic Chemistry and Catalysis, Prof. de Jongh, Prof. de Jong,) mit Arbeiten zur Wasserstoffspeicherung in nanostrukturierten Metallhydriden. Ende 2009 schloss er sich als Nachwuchsgruppenleiter der Arbeitsgruppe von Prof. Jürgen Janek am Physikalisch-Chemischen Institut der Justus-Liebig-Universität Gießen an und forschte an Materialien für elektrochemische Energiespeicher. Seit April 2015 ist er W3-Professor am Institut für Technische Chemie und Umweltchemie an der Friedrich-Schiller-Universität Jena.

Einen tabellarischen Lebenslauf finden Sie hier.
Eine Liste der Publikationen finden Sie hier.


Energy storage materials / Electrochemistry                                          

Philipp Adelhelm is a materials scientist and received his education at the University of Stuttgart and the Max-Planck-Institute for Metals Research. After graduation in 2004, he joined the group of Prof. Markus Antonietti at the Max-Planck-Institute of Colloids and Interfaces in Potsdam, Germany, and worked on the synthesis and characterization of carbon materials with tailored porosity. He received his PhD in physical chemistry in 2007 and continued his academic career as a post doc at the Debye Institute of Nanomaterials Science in Utrecht, The Netherlands, under supervision of Prof. Petra de Jongh and Prof. Krijn de Jong studying sodium and magnesium based hydrogen storage materials. During his stay as group leader at the Justus-Liebig-University Giessen, Germany (Institute of Physical Chemistry, RG Prof. Juergen Janek) his research aimed at exploring the cell chemistry of sodium based battery systems with the focus on carbon materials, conversion reactions, sodium/air and low temperature sodium/sulfur systems. Since April 2015, he is professor at the Institute of Technical Chemistry and Environmental Chemistry (ITUC) at the Friedrich-Schiller-University Jena. He is member of the Jena Center for Energy and Environmental Chemistry Jena (CEEC Jena).He is part of the directorate of the Working group "Chemistry and Energy" of the GDCh ( and member of the advisory boards of the journals Journal of Materials Chemistry A (RSC publishing), Energy Technology (Wiley-VCH) and Batteries & Supercapacitors (Wiley-CH).

Research interests:

  • (Solid State) Electrochemistry
  • Lithium-ion and sodium-ion batteries
  • Alternative battery concepts (Solid state batteries, Metal-Sulfur batteries)Electrode materials (carbons, oxides, sulfides) based on abundant elements
  • Thin film materials
  • Electrocatalysis (CO2 reduction)

Current research projects are supported by the Friedrich-Schiller-University Jena, the state of Thuringia (Pro Excellence program), the German Research Foundation (DFG), the Sino-German Center (CDZ) and the German Federal Ministry of Education and Research (BMBF).

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Selected research projects and publications:




Sodium as alternativ to Lithium?

Lithium-ion and sodium-ion batteries share many common features but also many surprising differences. Understanding the influence of ion size on the cell chemistry of batteries is an intriguing research field. Moreover, the abundance of sodium is highly attractive for developing low cost, large scale energy stores.

Adelhelm P, Hartmann P, Bender CL, Busche MR, Eufinger C, Janek J, From lithium to sodium: cell chemistry of room temperature sodium-air and sodium-sulfur batteries, Beilstein Journal of Nanotechnology 6, 2015 (open access)

         Nayak PK, Yang L, Brehm W, Adelhelm P; From lithium-ion to sodium-ion batteries: Advantages, Challenges, and Surprises, Angew. Chem. Int. Ed., 57, 2018, (Review)

    P. Adelhelm; Editorial : Energy, Batteries and Simple Math; Angew. Chemie Int. Ed.; 2018

     Editorial in Englisch: // Editorial in Deutsch:




Graphite for sodium-ion batteries

Although being the standard anode material in lithium-ion batteries (LIBs), graphite was considered to fail application in sodium-ion batteries (NIBs) because the Na-C system lacks suitable binary intercalation compounds. We showed that this limitation can be circumvented by using co-intercalation phenomena in a diglyme-based electrolyte. Highlights of the electrode reaction are its high energy efficiency, the small irreversible loss during the first cycle, and a superior cycle life with capacities close to 100mAhg1 for 1000 cycles and coulomb efficiencies >99.87%. Maybe most intriguingly, this reaction might be the first graphite electrode reaction for high energy batteries that operates without a solid electrolyte interphase (SEI).

         Jache B and Adelhelm P; Use of Graphite as a Highly Reversible Electrode with Superior Cycle Life for Sodium-Ion Batteries by Making Use of Co-Intercalation Phenomena, Angew. Chemie Int. Ed. 53, 2014

         Jache B, Binder J, Abe T, A comparative study on the impact of different glymes and its derivatives as electrolyte solvents for graphite co-intercalation electrodes in lithium-ion and sodium-ion batteries; Phys. Chem. Chem. Phys., 18 2016,

        Goktas M, Bolli C., Berg E.J., Novak P., Pollok K, Langenhorst F., v. Roeder M., Lenchuk O, Mollenhauer D., Adelhelm P.; Graphite as Cointercalation Electrode for Sodium-Ion Batteries: Electrode Dynamics and the Missing Solid Electrolyte Interphase (SEI), Adv. Energy. Materials, 2018, 201702724




The sodium superoxide battery


In the search for room-temperature batteries with high energy densities, rechargeable metal-air (more precisely metal-oxygen) batteries are considered as particularly attractive owing to the simplicity of the underlying cell reaction at first glance. Here we report on a Na-O2 cell reversibly discharging/charging at very low overpotentials (< 200mV) and current densities as high as 0.2mAcm−2 using a pure carbon cathode without an added catalyst. Crystalline sodium superoxide (NaO2) forms in a one-electron transfer step as a solid discharge product. This work demonstrates that substitution of lithium by sodium may offer an unexpected route towards rechargeable metal-air batteries.

Hartmann P, Bender CL, Vračar M, Dürr AK, Garsuch A, Janek J, Adelhelm P, A rechargeable room-temperature sodium superoxide (NaO2) battery, Nature Materials 12, 2013

Bender CL, Hartmann P, Vracar M, Adelhelm P, Janek J, On the Thermodynamics, the Role of the Carbon Cathode, and the Cycle Life of the Sodium Superoxide (NaO2) Battery, Adv. Energy Mater. 4, 2014

Bender CL, Schroeder D, Pinedo R, Adelhelm P, Janek J, One- or Two-Electron Transfer? The Ambiguous Nature of the Discharge Products in Sodium-Oxygen Batteries, Angewandte Chemie Int. Ed., 2016


Room-temperature sodium-sulfur batteries

The cell chemistry of sodium/sulfur cells operating at room temperature (RT-Na/S cells) is being studied electrochemically and structurally. We show by means of X-ray photoelectron spectroscopy that the cell reaction is incomplete but prove that the end members of the cell reaction (S and Na2S) form among the expected polysulfide species Na2Sx. The sulfur utilization can be improved by employing a solid electrolyte membrane (beta″-alumina) that prevents the diffusion of the soluble polysulfide species toward the sodium side. As an important finding, the Na+ conduction within the solid electrolyte phase and across the two liquid/solid interfaces results in only small overpotentials. Also, the thermodynamic properties of RT-Na/S cells operating at room temperature are discussed and compared with the currently much more studied RT-Li/S cells.

Wenzel S, Metelmann H, Raiß C, Dürr AK, Janek J, Adelhelm P, Thermodynamics and cell chemistry of room temperature sodium/sulfur cells with liquid and liquid/solid electrolyte, Journal of Power Sources 243, 2013

Adelhelm P, Hartmann P, Bender CL, Busche MR, Eufinger C, Janek J, From lithium to sodium: cell chemistry of room temperature sodium-air and sodium-sulfur batteries, Beilstein Journal of Nanotechnology 6, 2015 (open access)

Busche MR, Drossel T, Leichtweiss T, Weber DA, Falk M, Schneider M, Reich ML, Sommer H, Adelhelm P, Janek J Dynamic formation of a solid-liquid electrolyte interphase and its consequences for hybrid-battery concepts, Nature Chemistry 8, 2016

          Medenbach L, Adelhelm P.; Cell Concepts of Metal-Sulfur Batteries (Metal = Li, Na, K, Mg): Strategies for Using Sulfur in Energy Storage Applications, Topics in Curr. Chem., 375, 2017



Conversion reactions for sodium-ion batteries

Research on sodium-ion batteries has recently been rediscovered and is currently mainly focused on finding suitable electrode materials that enable cell reactions of high energy densities combined with low cost. Naturally, an assessment of potential electrode materials requires a rational comparison with the analogue reaction in lithium-ion batteries. In this paper, we systematically discuss the broad range of different conversion reactions based on their basic thermodynamic properties and compare them with their lithium analogues. Capacities, voltages, energy densities and volume expansions are summarized to sketch out the scope for future studies in this research field. We show that for a given conversion electrode material, replacing lithium by sodium leads to a constant shift in cell potential DE°(Li-Na) depending on the material class. For chlorides DE°(Li-Na) equals nearly zero. Next to the thermodynamic assessment, results on several conversion reactions between copper compounds (CuS, CuO, CuCl, CuCl2) and sodium are being discussed.

Klein F, Jache B, Bhide A, Adelhelm P, Conversion reactions for sodium-ion batteries, Phys. Chem. Chem. Phys., 15, 2013

Klein F, Pinedo R, Hering P, Polity A, Janek J, Adelhelm P, Reaction Mechanism and Surface Film Formation of Conversion Materials for Lithium- and Sodium-Ion Batteries: A XPS Case Study on Sputtered Copper Oxide (CuO) Thin Film Model Electrodes, J. Phys. Chem. C, 12, 2016

Klein, F, Pinedo R, Berkes B, Janek J, Adelhelm A, Kinetics and Degradation Processes of CuO as Conversion Electrode for Sodium-Ion Batteries: An Electrochemical Study combined with pressure monitoring and DEMS, J. Phys. Chem. C, 121 (16), 2017



Hydrogen storage

Hydrogen is expected to play an important role as an energy carrier in a future, more sustainable society. However, its compact, efficient, and safe storage is an unresolved issue. One of the main options is solid-state storage in hydrides. Unfortunately, no binary metal hydride satisfies all requirements regarding storage density and hydrogen release and uptake. In this Review we discuss the large impact of nanosizing and -confinement on the hydrogen sorption properties of metal hydrides. We illustrate possible preparation strategies, provide insight into the reasons for changes in kinetics, reversibility and thermodynamics, and highlight important progress in this field.

de Jongh PE, Adelhelm P.; Nanosizing and Nanoconfinement: New Strategies Towards Meeting Hydrogen Storage Goals. Chemsuschem 3, 2011 (Review)

Adelhelm P, de Jongh PE; The impact of carbon materials on the hydrogen storage properties of light metal hydride, J. Mater Chem., 21, 2011

Carbon materials and nanostructures

In this paper, we report on Li storage in hierarchically porous carbon monoliths with a relatively higher graphite-like ordered carbon structure. Macroscopic carbon monoliths with both mesopores and macropores were successfully prepared by using meso-/macroporous silica as a template and using mesophase pitch as a precursor. Owing to the high porosity (providing ionic transport channels) and high electronic conductivity, this porous carbon monolith with a mixed conducting 3D network shows a superior high-rate performance if used as anode material in electrochemical lithium cells. A challenge for future research as to its applicability in batteries is the lowering of the irreversible capacity.

Hu YS, Adelhelm P, Smarsly BM, Hore S, Antonietti M, Maier J., Synthesis of hierarchically porous carbon monoliths with highly ordered microstructure and their application in rechargeable lithium batteries with high-rate capability, Adv. Funct. Mater. 17, 2007

Adelhelm P, Hu YS, Chuenchom L, Antonietti M, Smarsly BM, Maier J.; Generation of hierarchical meso- and macroporous carbon from mesophase pitch by spinodal decomposition using polymer templates, Adv. Mater. 19, 2007

Jache A, Neumann C, Becker J, Smarsly BM, Adelhelm P. Towards commercial products by nanocasting: characterization and lithium insertion properties of carbons with a macroporous, interconnected pore structure, J. Mater. Chem. 22, 2012

Raiß C, Peppler K, Janek J, Adelhelm P, Pitfalls in the chararcterization of sulfur/carbon nanocomposite materials for lithium-sulfur batteries, Carbon, 79, 2014

Jan SchönherrJohannes R BuchheimPeter ScholzPhilipp Adelhelm (2018)  Boehm Titration Revisited (part II): A Comparison of Boehm Titration with other Analytical Techniques on the Quantification of Oxygen-Containing Surface Groups for a Variety of Carbon Materials C - Open Access Journal of Carbon Research 4:  22, 2018

Jan SchönherrJohannes BuchheimPeter ScholzPhilipp Adelhelm (2018)  Boehm Titration Revisited (part I): Practical Aspects for Achieving a high Precision in Quantifying Oxygen-Containing Surface Groups on Carbon Materials C - Open Access Journal of Carbon Research, 2018