Saturday, 03 May, 2014
Bimodal Mesoporous Carbon Nanofibers with High Porosity: Freestanding and Embedded in Membranes for Lithium–Sulfur Batteries
G. He, B. Mandlmeier, J. Schuster, L. Nazar, and T. Bein -
Chem. Mater., doi: 10.1021/cm403740r, published online: 3 May 2014
We demonstrate a synthetic approach for highly ordered hexagonal mesoporous carbon nanofibers with bimodal porosity, with an extremely high surface area and a high inner pore volume of 1928 m2/g and 2.41 cm3/g, respectively. A tubular silica template acts as an alternative fiber template for anodic alumina membranes. The sulfur cathode fabricated with the nanofibers shows much better electrochemical performance compared with our previously reported BMC-1/S cathodes by achieving a more homogeneous sulfur distribution in the carbon nanofiber framework. It is also noted that the variation of porous architectures of the carbon framework (i.e., low volumetric ratio of small mesopores over the total pore volume) results in very different electrochemistry, suggesting the significance of porosity optimization for sulfur electrodes.