Enhancement of electrochemical performance in lithium coating graphite synthesized by ball-milling method

초록

Several types of carbonaceous materials used as the negative electrode for lithium-ion rechargeable batteries have attracted a great deal of global attention. Because the use of carbonaceous materials can avoid the dendrite growth associated with metallic lithium upon charging of the batteries, carbonaceous materials can replace lithium metal in secondary lithium-ion batteries. Among carbonaceous materials, natural graphite with hexagon structure in plan is generally found in most commercial products in the market due to its advantages such as flat and low working voltage with respect to lithium metal. Specifically, natural graphite is recommended as a potential material for anodes in lithium-ion batteries due to cost considerations. However, natural graphite has many problems such as large irreversible capacity, poor cyclability and rate capability. In this work, Lithium coating natural graphite powders have been synthesized by ball-milling method. Lithium coating natural graphite powders were characterized by X-ray diffraction, charge/discharge cycling, scanning electron microscope, impedance analyzer, and atomic force microscope. Li coating natural graphite powders synthesized by ball-milling method show excellent capacity retention (358 mAh/g, 99 %).