Design optimization of battery systems by multiphysics simulation

IAV has developed a multiphysics simulation approach to optimize the design of automotive traction batteries. In 2014 IAV started battery technology development of bipolar Li-Ion battery system named EMBATT Chassis-embedded Energy (www.embatt.de). The target of the approach is to design more efficient battery systems to reach electric driving distances up to 1000 km. This disruptive technology gets rid of convention system decomposition from pack to cell, while the vehicle body can be used as battery housing. This paper is related to simulation methods and tools to optimize cell design of EMBATT and safety aspects of the conventional batteries.

The first step of the optimization takes place into the cell itself, using electrochemical simulation to define pre-optimized characteristics of the electrodes like thickness and porosity. The next step is a simulation for the design optimization of electrical connection inside and outside of the cell to reduce the power losses and effects of cooling. The last step is related to the investigation of the development of cell-to-cell thermal propagation inside a battery pack to reach the expected safety level. This multiphysics simulation approach (electrochemical, electric and thermal) allows improving the battery system development efficiency and making it cheaper for our customers thanks to the reduction of prototypes and tests in early development stages.