关键词: 锂硫电池, 硫电极, 聚苯胺, 升华物质

Abstract: An advance method for preparing polyaniline-coated hollow sulfur material using sublimate material ADD(2,4,6-tri(propan-2-yl)-1,3,5-trioxane) as a template was developed for lithium-sulfur battery. At first, the smashed ADD particles were coated by a sulfur layer through the reaction of Na₂S₂O₃ with diluted HCl. Then polyaniline layer was coated again on the surface of sulfur layer through the reaction of aniline with (NH₄)₂S₂O₈. After being dried at 60 ^oC for 12 h, the ADD in such a composite evaporated totally, and resulted in the formation of polyaniline-coated hollow sulfur composite. The SEM, TEM and TG measurements showed, that the particle size of as prepared polyaniline-coated hollow sulfur composite was about 2 μm, and the content of sulfur in the composite was 61.1%. The first discharge capacity was 776.2 mAh·g^-1 with a coulombic efficiency of 95.9%, at charge-discharge current of 500 mA·g^-1. After 100 cycles, the discharge capacity remained 524.7 mAh·g^-1. Because the polyaniline layer could inhibit the diffusion of polysurfides to outside of membrane, the hollow space in the core could buffer the volume change of sulfur during cycling. The discharge capacity and the charge-discharge stability of polyaniline-coated hollow sulfur were much higher than those of hollow sulfur without coating polyaniline, as well as those of chemical prepared sulfur. This new method for preparing polyaniline-coated hollow sulfur material is simple, low cost, and may have a promising prospect for the practical application.

Key words: Lithium-sulfur battery, sulfur cathode, polyaniline, sublimate material