CeO2 nanoparticles decorated CMK-3 as high-performance sulfur host for Li-S batteries

The development of Li-S batteries is hindered by some inherent drawbacks such as the shuttle effect of lithium polysulfides and the volume expansion of sulfur. Herein, 3-6 nm CeO2 nanoparticles decorated CMK-3 (CMK-3 @CeO2) is prepared and used as the sulfur host for Li-S batteries. As a conductive carbon support, CMK-3 can improve the electrical conductivity of sulfur-based electrode, and its mesopores pro-vide the space required for the volume expansion of sulfur. Meanwhile, the decorative CeO2 nanoparticles can not only change the non-polar carbon surface into the polar CeO2 surface for capturing lithium polysulfides, but also accelerate the redox reaction of lithium polysulfides, which effectively inhibits the shuttle effect of lithium polysulfides. Therefore, compared to pure CMK-3 supported sulfur (CMK-3 @S), CMK3 @CeO2 supported sulfur (CMK-3 @CeO2 @S) exhibits better electrochemical performance, such as a discharge capacity of 686 mA h g(-1) after 800 cycles at 1 C. Besides, the size effect of CeO2 nanoparticles on the electrochemical performance of CMK-3 @CeO2 @S is also studied. This work provides a simple method for improving the electrochemical performance of CMK-3 as the sulfur host, and this strategy can be extended to the other metal oxides decorated sulfur host materials. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

The study successfully improved the performance of Li-S batteries by preparing CMK-3 @CeO2 as the sulfur host, enhancing the cycling stability and discharge capacity of sulfur. This work provides a new perspective for designing more metal oxide-decorated sulfur hosts in the future.