Polydopamine blended with polyacrylic acid for silicon anode binder with high electrochemical performance

Polyacrylic acid (PAA) is one of the commonly used binders for Si anodes in lithium battery. However, it cannot accommodate huge volume change of the Si anodes during the lithium insertion/delithiation process, which would cause a sharp attenuation of the capacity and cycle performance of the Si-based lithium batteries. Herein, we present a polydopamine (PDA)/PAA composite binder for Si anodes in lithium batteries. This PDA-PAA binder has a three-dimensional network structure and provides a strong adhesion between the active materials and the current collector. When PDA-PAA is used for Si anode, the lithium battery demonstrates a high specific capacity of 2383 mAh g−1 at the 2C with 77.7% capacity retention after 100 cycles.