Poly(acrylic acid) (PAA) is the most established binder for pure Si electrodes, primarily relying on abundant polar carboxylic groups that enable strong hydrogen bonding with the Si surface. Despite these advantageous properties, the cycling performance of the fabricated Si anodes still far from meeting the standards required for practical applications.
Herein, we propose a reactive polyacrylate binder that can accommodate the volumetric expansion of Si anodes. The binder consists of a uniform mixture of PAA and polyacrylate crosslinker, which forms a network structure upon curing at high temperatures. In this network, PAA effectively maintains the integrity of the electrode through strong hydrogen bonding with Si particles, while crosslinking with polyacrylate crosslinker chains simultaneously enhances its mechanical strength. The elasticity of the binder was carefully adjusted by controlling the ratio of monomers in the polyacrylate crosslinker to effectively accommodate Si volume changes. As a result, the binder demonstrates enhanced cycling stability and rate performance compared to conventional PAA-based binders.