摘要
To suppress shuttling effect and improve electrochemical performance of the sulfur cathode for lithium- sulfur 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 pow-ders. 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 MoS2/5. The capacity of the MoS2 @S spheres can reach 1185.7 mA h g^-1 at 0.2 C and 955.1 mA h g^-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.
To suppress shuttling effect and improve electrochemical performance of the sulfur cathode for lithium- sulfur 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 pow-ders. 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 MoS2/5. The capacity of the MoS2 @S spheres can reach 1185.7 mA h g^-1 at 0.2 C and 955.1 mA h g^-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.
基金
supported by the National Natural Science Foundation of China(Nos.51472083 and 51402101)
