Modeling of Mass and Charge Transport in Li-ion Battery Electrolytes – the Impact of Ion Pairs

M. Mutke, and H.-D. Wiemhöfer
Institute of Inorganic and Analytical Chemistry
University of Muenster
Muenster, Germany

In this contribution, ionic mass and charge transport in Li-battery electrolytes is modeled. In particular, incomplete dissociation of the Li-salt, which is a common feature of many commercial electrolytes and which has so far been neglected in most electrolyte models, is considered. For electrolytes in cells under various charging/discharging conditions, the development of local concentration gradients and the resulting detrimental consequences such as increased electrolyte resistance are simulated.

With the presented model, a better understanding of the impact of ion association on the Li-transport in electrolytes is obtained which will help to improve battery electrolyte systems. Moreover, as this electrolyte model allows for integration into a complete cell model, it is an integral part for future simulations of Li-ion cells.