Yo Chan Jeong

Easy preparation of partially-opened carbon nanotubes by simple air oxidation for high performance Li–S batteries

The thermal decomposition behavior of multi-walled carbon nanotubes (MWCNTs) was revisited to prepare partially opened MWCNTs by a simple air oxidation method which allows mass-productivity. As a promising matrix for sulfur cathodes, the partially opened MWCNTs can incorporate sulfur in hidden internal areas in the carbon nanotubes, leading to a homogeneous distribution through the MWCNT matrix. The resulting materials enable Li–S batteries to exhibit greatly enhanced electrochemical performance.

Morphochemical imprinting of melamine cyanurate mesocrystals in glucose-derived carbon for high performance lithium ion batteries

A novel dual imprinting method is suggested to synthesize pyridinic N-enriched, hierarchically porous carbon. Rose-like melamine cyanurate (MCA) mesocrystals are prepared by simple self-assembly and utilized as a sacrificial template. The unique morphological and chemical features of the MCA are imprinted in the carbon source during carbonization. Curled graphene-like layers with a high nitrogen content (19.9 at%, especially 8.9 at% of pyridinic N) are interconnected to form a unique red blood cell-shaped morphology with a hierarchical pore structure. The resulting material exhibits an outstanding electrochemical performance (2019 mA h g−1 at 100 mA g−1 and 643 mA h g−1 at 2000 mA g−1 after 250 cycles) when evaluated as an anode material for lithium ion batteries. Furthermore, this novel imprinting strategy can provide a simple and efficient methodology to produce pyridinic N-enriched, hierarchically porous carbonaceous materials for extensive applications.