High efficiency immobilization of sulfur on Ce-doped carbon aerogel for high performance lithium-sulfur batteries

Abstract

A sulfur-carbon composite from sulfur and carbon aerogel decorated with ultrafine CeO2 nanoparticles has been prepared by a conventional sol-gel strategy as a host material of the sulfur cathodes for lithium-sulfur batteries. The physical and electrochemical properties of the prepared composite materials have been evaluated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N2 sorption isotherms, X-ray photoelectron spectroscopy and electrochemical measurements. Apart from offering flexible confinement function, carbon aerogels decorated with CeO2 are also found to suppress the loss of polysulfide ions. The Ce2-CA/S cathode with Ce/C molar ratio of 0.0233 delivers high initial discharge capacity of 1381mAhg−1 at 0.2 C and remains 1127.6mAhg−1 after 100 cycles. The sulfur electrodes have excellent rate performance with initial discharge capacity of 768.5 mAh g−1 at 5 C.