Core-shell structured MoS2@S spherical cathode with improved electrochemical performance for lithium-sulfur batteries
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2018年第10期
论文作者：Songpu Cheng Xiaohong Xia Hongbo Liu Yuxi Chen
文章页码：1912 - 1918
摘 要：To suppress shuttling effect and improve electrochemical performance of the sulfur cathode for lithiumsulfur batteries, core-shell structured MoS2 @S spherical cathode has been synthesized through a chemical route using MnC03 as template. The MoS2 shells consist of MoS2 nanosheets. For comparison, MoS2/S cathode has also been synthesized through melting and diffusion of sulfur to commercial MoS2 powders. The electrochemical performance of the MoS2@S and MoS2/S cathodes have been evaluated using cyclic voltammetry, discharge/charge cycling, electrochemical impedance spectroscopy coupled with impedance fitting. The electrochemical performance of the MoS2@S spherical cathode has been much improved compared with that of MoS2/S. The capacity of the MoS2@S spheres can reach 1185.7 mAhg-1 at 0.2 C and 955.1 mAhg-1 at 1 C with initial-cycle coulombic efficiency of 90%. The capacity fading of each cycle is 0.1 % during 200 lithiation/delithiation cycles. The MoS2@S spherical cathode with high cyclic capacity and stability is promising cathode candidate for lithium-sulfur batteries.
Songpu Cheng，Xiaohong Xia，Hongbo Liu，Yuxi Chen
College of Materials Science and Engineering, Hunan University
摘 要：To suppress shuttling effect and improve electrochemical performance of the sulfur cathode for lithiumsulfur batteries, core-shell structured MoS2 @S spherical cathode has been synthesized through a chemical route using MnC03 as template. The MoS2 shells consist of MoS2 nanosheets. For comparison, MoS2/S cathode has also been synthesized through melting and diffusion of sulfur to commercial MoS2 powders. The electrochemical performance of the MoS2@S and MoS2/S cathodes have been evaluated using cyclic voltammetry, discharge/charge cycling, electrochemical impedance spectroscopy coupled with impedance fitting. The electrochemical performance of the MoS2@S spherical cathode has been much improved compared with that of MoS2/S. The capacity of the MoS2@S spheres can reach 1185.7 mAhg-1 at 0.2 C and 955.1 mAhg-1 at 1 C with initial-cycle coulombic efficiency of 90%. The capacity fading of each cycle is 0.1 % during 200 lithiation/delithiation cycles. The MoS2@S spherical cathode with high cyclic capacity and stability is promising cathode candidate for lithium-sulfur batteries.
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