Ab Initio-Based Multiscale Simulations of Conversion Reactions in Lithium-Ion Batteries

The development of theoretical methods to correlate the chemical and structural properties of electrode materials with their electrochemical behavior in energy storage devices is of crucial importance for consistent interpretation of experimental data and for their optimization toward end-user applications [1-3].

In this work a new multiscale model is presented allowing to describe solid phase formation and separation during discharge-charge in Lithium Ion Battery (LIB) cathodes using conversion materials such as CoO, CuO or CoP [4-5]. The adopted theoretical framework extends a previous approach extensively developed for the multiscale modeling of fuel cells [6-7].  The model is supported on a Cahn-Hilliard-based phase field approach parametrized with ab initio-extracted parameters such as the interphase (solid/solid, solid/liquid) energies and binary (solid/solid phase) diffusion coefficients [8-9].  The electrochemical conversion reaction MO + Li⁺ + e^- ↔ Li₂O + M° and associated Li⁺ and e^- transports are locally resolved across the multiphase MO/Li₂O/M° system.  The integration of this multiscale phase field model into a cell level model accounting for electrolyte/active material interfaces (in house developed simulation package "MS LIBER-T" [10]) allows simultaneously simulating the microstructural evolution of the multiphase active particles (Figure) and the associated potential vs. capacity characteristics during the LIB discharge and charge. Simulation results provide good agreement with experimental findings, in particular for the evolution of the active particles during discharge from microstructured to nanostructured morphologies [4-5,11].

References

[1] A.A. Franco, RSC Advances, 3 (32) (2013) 130.

[2] A.A.Franco, Multiscale Modeling of Electrochemical Conversion and Storage in: The Encyclopedia of Applied Electrochemistry, R. Savinell, K. Ota and G. Kreysa Eds. (Springer) (2013).

[3] A.A. Franco, K.H. Xue, ECS J. Solid State Sc. Tech., 2 (10) (2013) M3084.

[4] P. Poizot et al., Nature, 407 (2000) 496.

[5] J.M. Tarascon et al., Chem. Mater., 16(2004) 1056.

[6] R. Ferreira de Morais, D. Loffreda, P. Sautet, A. A. Franco, Electrochim. Acta, 56 (28) (2011) 10842.

[7] A. A. Franco, P. Schott, C. Jallut, B. Maschke, Fuel Cells, 7 (2007) 99

[8] A.-L. Dalverny, J.-S. Filhol, M.-L. Doublet, J. Mater. Chem., 21 (2011) 10134.

[9] R. Khatib, A.L. Dalverny, M. Saubanère, M. Gaberscek, M.L. Doublet, J. Phys. Chem. C, 117 (2013) 837.

[10] www.modeling-electrochemistry.com

[11] M. Ebner et al., Science 342 (2013) 716.

Figure. Example of conversion electrode microstructural evolution, during the LIB discharge, calculated by multiscale phase field simulations.