Polymeric binder interactions with silicon were investigated as a function of electrode processing and electrochemical behavior. Using ultra-small angle neutron scattering, the evolution of the dynamics between a poly(acrylic acid) and silicon slurry showed that, under shear conditions, the slurry aggregated heavily when compared to the no shear condition. This behavior is undesirable as silicon anode slurries must de-agglomerate under shear conditions for a uniform electrode cast, which facilitates even lithiation across the anode. Electrodes made from these slurries show the connection between the binder/silicon interaction and electrochemical behavior. Additionally, the role of the silicon surface chemistry on the rheology of the electrode slurry was elucidated and connected to electrode processing and electrochemical performance. Based on these results, the binder for the silicon anode materials may need to be re-evaluated in order to improve the viability of silicon anodes.

Acknowledgement: This work was supported by the US Department of Energy’s Office of Energy Efficiency and Renewable Energy through the Vehicle Technology Office (Brian Cunningham Program Manager).