Polydopamine Wrapping Silicon\nCross-linked with Polyacrylic Acid as High-Performance Anode for Lithium-Ion\nBatteries

A robust silicon electrode for lithium-ion\nbattery has been developed via prepolymerizing dopamine on silicon\nparticle surface and then chemical binding with poly­(acrylic acid)\n (PAA). In this favorable electrode, silicon nanoparticles are covered\nby a thin layer of polydopamine (PD) through firm hydrogen bonds between\nphenolic hydroxyl and hydroxyl, while the elastic polymer layer reacts\nwith PAA binder to form three-dimensional cross-linked binding system.\nThe Si@PD/PAA electrode exhibits more stable cycle performance than\nconventional electrodes. In the case of thick electrode, a capacity\nof 3.69 mA h cm–2 and fairly good rechargeability\nfor 80 cycles can be achieved.