A 3D Configuration Electrode for Lithium-Sulfur Batteries

摘要

Lithium-sulfur batteries have become one of the most promising high-energy batteries owing to their high energy density and low cost. Nevertheless, one of the major problems is the infamous shuttle effect of polysulfides, which causes active material sulfur loss and low Coulombic efficiency. Here, we designed a 3-D configuration electrodes. Multi-walled carbon nanotubes paper (MWCNTsP) was used as the current collector, and MWCNTs film was used as the interlayer (MWCNTsI) between the positive electrode and the separator. The unique configuration retarded the dissolution and dispersion of polysulfides. The electrochemical tests showed that the initial discharge capacity reached 1352 mAh/g and the Coulombic efficiency reached around 100% with the 3-D configuration electrode (MWCNTsP-S@MWCNTsI). The discharge capacity remained 1028 mAh/g after 20 cycles. Additionally, the batteries maintained a specific capacity of 902 mAh/g, 782 mAh/g and 509 mAh/g at the current rate of 1C, 2C and 5C, respectively.