A novel Pt/MoS2/CNT composite catalyst for the positive electrode of a Li-O2 battery

Abstract

Abstract A Pt/MoS2/CNT composite catalytic system for the positive electrode of a lithium-oxygen battery (LOB) was synthesized by the polyol method. It was established that the modification of MoS2 with platinum leads to an increase in electron density in the conduction band and an increase in electrical conductivity as compared to the characteristics of unmodified MoS2. The introduction of a mesoporous carbon material (carbon nanotubes, CNTs) provides a surface available for lithium peroxide accumulation. In this case, the Pt/MoS2/CNT system exhibits bifunctional catalytic properties, reducing the charge voltage and increasing the discharge capacity of a LOB as compared to the MoS2/CNT catalyst. In addition, the Pt/MoS2/CNT composite demonstrates a higher activity and reversibility in the oxygen reduction reaction than Pt/CNT, probably due to an increased corrosion resistance of MoS2. According to the results of cyclic tests, LOBs with the Pt/MoS2/CNT system can withstand at least 120 consecutive cycles versus 80 cycles for the MoS2/CNT catalyst.