The effect of cerium oxide addition on the electrochemical properties of lithium-sulfur batteries

The effects of various CeO2 additions on the electrochemical properties of lithium-sulfur batteries have been studied over synthesizing the sulfur-host matrix with unique surface appearance. It has been revealed that the appropriate additions of CeO2 (0.70-3.65 wt%) to the porous carbon were beneficial to enhance the cycle performance. The polar metal oxide CeO2 can chemically adsorb the sulfur species and promote redox reaction through catalysis properties. Meanwhile, the porous carbon can enhance the conductivity of cathode and form a favorable physical barrier to block the diffusion of polysulfide with abundant pore structures. As results, the CS-CeO2 composite (with 1.84 wt% CeO2) exhibits significantly improved electrochemical performance as a cathode material for Li-S batteries. The initial discharge capacity of assembled battery is as high as 1434.1 mAh g(-1) at 0.05 C and the discharge capacity retains 873.6 mAh g(-1) with a low decay rate of 0.077% per cycle after 200 cycles at 0.2 C. When the area sulfur content is as high as 4.53 mg cm(-2), the CS-Ce2 cathode still retains a discharge capacity of 572.3 mAh g(-1) at 1 C after 100 cycles. (C) 2019 Elsevier B.V. All rights reserved.