(4bj) Silicon-Carbon Anode with Improved Structural Integrity for Lithium-Ion Batteries and Sulfur Cathode Encapsulated in Hollow Carbon Nanostructures for Lithium-Sulfur Batteries

The recent development of silicon-carbon composite anode with high energy and high power densities will be presented. This porous Si-C anode is directly synthesized on the current collector by carbonization of a precursor consisting of Si nanoparticles, polyacrylonitrile (PAN) and polystyrene (PS). The structural integrity is improved by the carbon framework obtained by carbonization of PAN, and the porous structure is obtained by the decomposition of PS. To ensure the uniform distribution of Si nanoparticles in the carbon framework, Si particles are grafted with PAN through emulsion polymerization. Development of sulfur cathode materials for lithium-sulfur batteries will also be presented. Sulfur is encapsulated into hollow carbon structures to improve the electrical conductivity and more importantly, to improve the cyclability of the sulfur cathode. The carbon capsules include carbon tubes synthesized with anodic aluminum oxide (AAO) template method, hollow carbon nanofibers from electrospin technique, and hollow carbon spherical structures using emulsion polymerization with various templates.