The hydrogen and
fuel cell center


Dipl.-Ing. Bernd Oberschachtsiek

technical operations manager ZBT &
Commissary Head of

Department Electrolysis

phone: +49 203 7598-4280
online form

Lithium-sulphur batteries

Lithium sulphur batteries have the potential to exceed the gravimetric energy density of lithium-ion batteries by three or four times. However, this potential was not fully tapped until now.

In general, the functional principle of a lithium-sulphur battery is similar to that of a lithium-ion battery. Also here, lithium-ions are exchanged between the electrodes. However, the reaction mechanism of a lithium-sulphur battery is much more complicated than the mechanism of a lithium-ion battery. During charge and discharge intermediates are formed which are soluble in the electrolyte resulting in a lower capacity retention compared to lithium-ion batteries. Additionally, the high rate capability of lithium-sulphur batteries is significantly lower than the high rate capability of lithium-ion batteries. This phenomenon can be explained by the low ionic and electrical conductivity of the sulphur based cathode active materials.



Operating principle of a lithium sulphur battery (charging)

Field of work


Since 2017 the ZBT deals with the enhancement of the electrode and cell design in different projects. For this purpose, the electrode composition is tailored to increase the capacity retention and the high rate capability. Besides the electrode development, the cathode active material lithium sulphide (Li2S) is synthesised at the ZBT since 2020. The surface of the so obtained Li2S is tailored by a project partner using advanced methods. So, the high rate capability as well as the lifetime should be enhanced.

The same methods are used to characterise the electrodes as for the analysis of lithium-ion-batteries. Furthermore, UV-VIS spectroscopy can be used to clarify the reaction mechanism.


Last update:  07.09.2023