Unlocking Stable Cycling in Silicon Kerf Waste Anodes with Recycled Polyacrylamide-Based Binders for Lithium-Ion Battery Applications

Kerf waste is a byproduct of the semiconductor industry and is a cost-effective source of high-purity Si, which is highly sought after for Li-ion battery anodes. However, recycled kerf waste contains particles with various sizes and morphologies that induce additional stresses during battery cycling and lack the chemo-mechanical advantages of nanostructured Si. In this study, a lithium polyacrylate/polyacrylamide (LiPAA/PAM) binder system that is specifically tuned for kerf Si active materials is developed and contrasted with the performance of PAM and CMC binders. The combined binder system benefits from covalent and hydrogen bonding, ionic cross-linking, and electrostatic interactions provided by carboxylate and amide groups. The recycled PAM binder alone delivered a ∼3× enhanced capacity retention compared to the CMC binder, which was further boosted by a factor of 2 with the addition of lithium polyacrylate (LiPAA), resulting in a specific capacity of 1528 mAh g –1 after extended cycling. The study shows that recycled LiPAA/PAM binder can unlock the use of silicon kerf waste as a cost-effective anode material, with improved electrochemical performance and reduced environmental footprint.