Synthesis of Porous Carbon Materials Using Silica Nanoparticles as Templates and Their Application to Lithium-Sulfur Batteries

Abstract

　Lithium-sulfur batteries are expected for the energy storage devices of renewable energy because of low cost and high capacity. However, the insulating property of sulfur is one of the challenges for their practical application. We synthesized silica nanoparticles-templated porous carbon (STPC) as a conductive material for the lithium-sulfur battery. Pore size and specific surface area of STPC were able to control by selecting size of silica nanoparticles. STPC synthesized with silica nanoparticles of 5 nm in diameter showed high specific surface area (1435 m²・g^－1) and retention of charge-discharge capacity after 20 cycles, while STPC synthesized with silica nanoparticles of 50 nm in diameter showed high initial discharge capacity (841 mA・h・g^－1). As the diameter of silica nanoparticles increased, the initial discharge capacity increased and the capacity retention rate decreased. Using silica nanoparticles of different diameter improved the capacity decay.