Preparation and Electrochemical Properties of S@C Composite Material with High Capacity and Ordered Alignment of Channels

The wood was pretreated with ammonia to remove the lignin from the wood , then heated under the protection of inert gas and activated by KOH , the three-dimensional ( 3D) carbon material with ordered alignment of channels and multi-pores was obtained. After melting and absorbing sulfur in a autoclave at 150 degrees C , a kind of S@C composite electrode material with high capacity was prepared. The composite was characterized by scanning electron microscopy ( SEM) , X-ray diffraction ( XRD) , Raman spectroscopy and N-2 adsorption-desorption analysis. The results show that the carbon material has a 3D structure with anisotropic channels and multi-level pores. The channels are arranged orderly in parallel with the growth direction of the tree trunk. In addition, there are many micropores on the inner wall of the carbon material activated by KOH. So the material has high pore volume and specific surface area. Furthermore, the Li/S battery was assembled by using S@C composite as cathode material. The electrochemical results show that the first discharge capacity of the S@C composite electrode material reaches 1595 mA . h /g, which is close to the theoretical specific capacity of sulfur electrode material( 1670 mA . h/g).