A Nitrogen-Doped Carbon Matrix Aiming at Inhibiting Polysulfide Shuttling for Lithium–Sulfur Batteries

Abstract

Lithium–sulfur (Li–S) batteries have been attracting great attention as promising rechargeable batteries because of their large specific capacity and high energy density. However, some technical problems still limit the commercialization value of Li–S batteries such as poor electrical conductivity, shuttle effects, and volume expansion. To overcome the aforementioned issues, N-doped carbon composites were synthesized via a one-step hydrothermal method. To obtain different N-doping configurations, a carbon precursor was annealed at different heating rates, resulting in different N-containing properties. The cell with the most content of pyridinic-N delivered the highest initial discharge capacity of ∼1121 mAh g–1, and the specific capacity still retained 605 mAh g–1 at 200 mA g–1 after 100 cycles. It was concluded that pyridinic-N has the most significant effect on immobilizing the soluble lithium polysulfides, which stabilized the cycle of Li–S batteries.