Hierarchical Porous Carbon Aerogels with VN Modification as Cathode Matrix for High Performance Lithium-Sulfur Batteries

The hierarchical porous carbon aerogel (CA) with vanadium nitride (VN) was effectively prepared via a facile in-situ method with organic acid catalyzing and non-supercritical drying. The surface morphology and structure of the VN/CA (VCA) composites, and the electrochemical performance of these composites based sulfur cathodes were investigated systematically. This mono-dispersed microsphere composite presents hierarchical pore and uniform dispersion of vanadium nitride, and effectively immobilizes the polysulfides due to the synergistic effects between the VN and CA matrix. Moreover, the VN on the CA has catalytic effect on the electrode reaction, displaying high discharge voltages. In particular, a higher initial discharge capacity of 1279 mAh g−1 can be obtained at 0.2 C, and it retains 1001 mAh g−1 after 100 cycles. Even at a higher rate of 1 C, the capacity still delivers 802 mAh g−1 after 100 cycles.