Ageing Model for Battery Simulations
The SEI (solid electrolyte interphase) layer on the anode of lithium ion batteries ages during battery cycling due to the imperfect passivation properties of the layer. SEI ageing is one of the major ageing mechanisms of batteries. The description and prediction of ageing mechanisms is vital for battery simulation software tools, which are used in engineering sciences for the design of new battery systems, e.g for electric cars. Simulation tools are also used in hardware-in-the-loop testing setups as shown in the figure above. In such test systems, engineers can quickly evaluate complicated load profiles under relatively realistic conditions. Since the SEI properties are often not considered in battery simulation software tools, ageing predictions of the software tools can be inaccurate.
In cooperation with Fraunhofer IEE (Institute for Energy Economics and Energy Systems Technology) in Kassel, SEI models are developed and employed in the BaSiS toolkit (Battery Simulation Studio). Advanced ageing models can lead to optimized operation control strategies and longer lifetime of batteries in operation.