High-Capacity Silicon-Carbon Anodes Enabled By Dispersing Nano Silicon Onto Natural Graphite for Lithium Ion Batteries

Abstract

Research on lithium ion batteries has attracted massive attention due to the development of electrical vehicles and portable devices as well as grid energy storage. Pursuit for higher capacity and better cycle life become crucial issue for lithium ion battery anode material. Among all the anode materials, silicon is one of the most promising candidate due to its high theoretical specific capacity (around 3579mAh/g). Graphite, which is the stae-of-the-art commercialized anode material, is known for its stable performance and high electrical conductivity. In this work, a high-capacity composite anode suitable for large-scale production has been synthesized and characterized by taking advantage of both silicon’s high capacity and graphite’s good stability. In this approach, maintaining good dispersion of nano-Si is a critical requirement, and the effects of different dispersants and polymeric binders, which also serve as carbon precursors, have been investigated. Silicon/carbon/graphite composites exhibit high capacity and better cycle life than simple mixing of silicon and graphite powder have been achieved. Figure 1