Modeling the volumetric expansion of the lithium-sulfur battery considering charge and discharge profiles

As an alternative battery technology to the established lithium-ion battery, the lithium-sulfur battery shows great potential due to its greater energy density, safety and possible lower material costs. In the next few years 500-600Wh kg-1 could be implemented. However, there are still challenges in the commercialization and condition monitoring of the battery. Conventional methods of the lithium-ion technology, such as state of charge prediction via open circuit voltage (the discharge curve/charge curve has two plateaus), as well as coulomb counting are ineffective for the lithium-sulfur battery. However, due to the continuous volumetric change during battery operation, this could be a possible approach to monitor and predict the condition of the battery. Therefore, this paper presents a model that determines the volumetric change as a function of a constant discharge/charge profile. The influence of the selected values is investigated by a parameter variation. The parameter set for the model is further characterized by a computer tomography measurement. The simulation model is verified by literature and measurement data. This modeling approach could influence the development of a future battery management system for lithium-sulfur battery.