Influence of Binder Property and Interaction on Electrode Microstructure Formation in Energy Storage

Abstract

Energy storage, such as lithium-ion batteries (LIBs), is key enabler for grid energy storage and vehicle electrification. The electrode microstructure, which is affected by processing scheme, plays an important role in determining the electrode property and performance.1-5In the multiphase electrode slurry, physicochemical interactions affect the assembly of active material and conductive additive particles. Additionally, the pattern of nanoparticle assembly is also affected by the solvent evaporation rate. Polymer-mediated nanoparticle assembly can be a promising method to control a composite microstructure.6 However, there are only a few studies focusing on the effect of binder interaction (such as binder molecular weight) on the electrode microstructure formation and the relative performance.7, 8 In the present study, we developed a mesoscale model accompanied by stochastic dynamics simulation to illustrate the influence of binder interaction and evaporation on microstructures during the electrode processing. Present simulations demonstrate that the lower drying temperature can produce electrode films with micropores as shown in Figs. 1 (a) ~ (c). The depth of micropores tends to increase as binder length (L) increases. Drying temperature affects binder distribution along thickness direction as shown in Fig. 1 (d). The lower drying temperature reduces the fraction of on-surface binder. Additionally, binder length also affects the binder distribution. It can be seen in Fig. 1 (d), that an increase of binder length is beneficial for keep high volume fraction of binder in the film which has implication in better mechanical stability of the electrode film. Refernces 1. J. Li, B. L. Armstrong, J. Kiggans, C. Daniel, and D. L. Wood III, Langmuir, 28 (8), 3783-3790 (2012). 2. H. Zheng, R. Yang, G. Liu, X. Song, and V. S. Battaglia, The Journal of Physical Chemistry C, 116 (7), 4875-4882 (2012). 3. G. Liu, H. Zheng, S. Kim, Y. Deng, A. Minor, X. Song, and V. Battaglia, J Electrochem Soc, 155 (12), A887-A892 (2008). 4. Z. Liu and P. P. Mukherjee, J Electrochem Soc, 161 (8), E3248-E3258 (2014). 5. Z. Liu, V. Battaglia, and P. P. Mukherjee, Langmuir, 30 (50), 15102-15113 (2014). 6. P. Akcora, H. Liu, S. K. Kumar, J. Moll, Y. Li, B. C. Benicewicz, L. S. Schadler, D. Acehan, A. Z. Panagiotopoulos, V. Pryamitsyn, V. Ganesan, J. Ilavsky, P. Thiyagarajan, R. H. Colby, and J. F. Douglas, Nat Mater, 8 (4), 354-359 (2009). 7. B.-R. Lee and E.-S. Oh, The Journal of Physical Chemistry C, 117 (9), 4404-4409 (2013). 8. N. Tasić, Z. Branković, Z. Marinković-Stanojević, and G. Branković, Science of Sintering, 44 (3), 365-372 (2012). Figure 1