Tin (Sn) has been widely studied as a promising anode material for high-energy and high-power-density Li-ion batteries owing to its high specific capacity. In this work, a water-soluble conductive polymer is studied as a binder for nanosized Sn anodes. Unlike conventional binders, this conductive polymer formed a conductive network, which maintained the mechanical integrity during the repeated charge and discharge processes despite the inevitable Sn particle pulverization. The resultant Sn anode without conductive additives showed a specific capacity of 593 mA h g-1 after 600 cycles at the current density of 500 mA g-1, exhibiting better cycling stability as well as rate performance compared to Sn anodes with conventional binders. Furthermore, it was also found that the conductive binder enhanced the formation of stable solid electrolyte interphase (SEI) layers.
Keywords: Li-ion batteries; conductive binder; solid electrolyte interface; tin anode; tin pulverization.