Suppression of Li deposition on surface of graphite using carbon coating by thermal vapor deposition process

10 wt.% carbon-coated natural graphite (NC-10) is prepared by thermal vapor deposition. The carbon coating is electrochemically investigated at −5 °C; it improves lithium intercalation in the graphite's interlayer spacing. NC-10 graphite clearly shows 3 voltage plateaus and a higher capacity during the first charge/discharge cycle at −5 °C than uncoated natural graphite. XRD study of the electrode after the first charging shows increased lithium intercalation into the graphite layers and also suppression of lithium deposition on the graphite's surface. Due to the homogeneous potential profile on the graphite surface, carbon coating enhance lithium intercalation at −5 °C. In addition, NC-10 shows less lithium deposition on the surface than bare natural graphite.

► Carbon coated natural graphite prepared by TVD. ► Increased lithium intercalation into graphite. ► Suppression of lithium deposition on the surface of graphite. ► Improved the safety of lithium ion batteries.