Understanding Binder–Silicon Interactions during Slurry Processing
Mary K. Burdette‐Trofimov, Beth L. Armstrong, Alexander M. Rogers, Luke Heroux, Mathieu Doucet, Guang Yang, Nathan D. Phillip, Michelle K. Kidder, Gabriel M. Veith
Abstract
The conformation of poly(acrylic acid) (PAA) as a function of shear during slurry processing to construct silicon-based anodes is elucidated via rheology-coupled ultra-small-angle neutron scattering (rheo-USANS). Rheo-USANS shows that PAA with encapsulated silicon exists as discrete aggregates that do not interact with one another. As a result, a well-connected matrix of silicon and carbon black dispersed in PAA does not exist; thus, the electrode is inhomogeneous. Raman mapping and X-ray photoelectron spectroscopy were used to confirm the electrode heterogeneity and further understand the cycling properties. These results are correlated to silicon surface chemistry to provide a pathway to making better electrodes.