Three-dimensional aluminum foam/carbon nanotube scaffolds as long- and short-range electron pathways with improved sulfur loading for high energy density lithium–sulfur batteries

Abstract

Conductive carbon scaffolds are efficient and effective to build advanced carbon/sulfur composite cathodes for lithium–sulfur (Li–S) batteries. However, the areal sulfur loading is commonly less than 4.0 mg cm−2, which limits the energy density and practical application of Li–S cells. In this contribution, three-dimensional (3D) aluminum foam/carbon nanotube (CNT) scaffolds were applied as the current collectors to build long- and short-range electron pathways and provided enough space for high sulfur loading. The sulfur loading amount on the 3D current collectors ranged from 7.0 to 12.5 mg cm−2. A high initial discharge capacity of 6.02 mAh cm−2 (860 mAh g−1) was achieved on an electrode with an improved sulfur loading of 7.0 mg cm−2. Therefore, the combination of 3D long-range current collectors and short-range CNT conductive scaffold provides an efficient and effective route to make full use of sulfur with a very high sulfur loading amount in a Li–S cell.