Place: EUROMAT 2013, Sevilla, Spain
During the development of high gravimetric and volumetric energy density materials for lithium ion batteries, deformation-caused failure during charge/discharge cycling poses one of the biggest problems. Periodic intercalation and deintercalation of Lithium into/from the electrode material lead to expansion and shrinkage that results in loss of contact between the charge collector and the electrode as well as crack growth in the electrode material itself. Both processes mean capacity loss and nally failure of the entire battery system. To tackle this issue, a large deformation model is needed which is capable of a quantitative simulation of these processes. We designed and implemented such a model into the OpenPhase software framework. The mechanical part was coupled with a thermodynamic description of the materials in the shape of free energy functions and their derivatives (chemical potentials and thermodynamic factors). The resulting approach was used to simulate lithium intercalation into electrode material particles and the resulting deformation and stress elds are presented in this contribution.