Effect of CeO2-x-CNT/S cathode on the electrochemical performance of lithium-sulfur batteries

Abstract

Despite extensive research into cerium oxide as a cathode for lithium-sulfur batteries, there are still problems with low specific capacity and high decay rate. This paper used a simple gas reduction method to prepare CeO2-x nanoparticles with more oxygen vacancies. It has been demonstrated experimentally that the presence of oxygen defects increases the electrochemical reaction rate. Using CeO2-x-CNT/S as cathode for lithium-sulfur battery not only improves the conductivity of cathode, but also restricts the movement of polysulfide. The CeO2-x-CNT/S cathode exhibits good electrochemical properties. The first discharge specific capacity of CeO2-x-CNT/S cathode is 1556.8 mAh g -1 at 0.1C. The initial discharge specific capacity is 1233.9 mAh g -1 at 0.5C, and has a small capacity decay rate after 600 cycles. It provides a new answer to the problems in lithium-sulfur batteries.