Exploration of High and Low Molecular Weight Polyacrylic Acids and Sodium Polyacrylates as Potential Binder System for Use in Silicon Graphite Anodes.

The commercialization of silicon anodes requires polymer binders that are both mechanically robust and electrochemically stable in order to ensure that they can accommodate the volume expansion experienced during cycling. In this study, we examine the use of both low and high molecular weight (MW) polyacrylic acids (PAAs), and sodium polyacrylates (Na-PAAs), at different degrees of partial neutralization, as a possible binder candidate for use in silicon graphite anodes. High MW PAAs were found to have stable capacity retentions of 672 mAh g for over 100 cycles, whereas with the low MW PAAs the capacity was found to already have declined to 373 mAh g after the first 30 cycles.