关键词: 锂硫电池, 累托石, 锂盐改性, 电化学性能

Abstract: In the secondary battery，the lithium-sulfur battery is used as a battery form in which sulfur is used as a positive electrode active material，and it has the characteristics of environmentally friendly raw materials and higher specific capacity than other conventional materials. However，the sulfur conductivity is extremely poor，the expansion ratio is large，and the lithium sulfide formed by the charge and discharge process is easily dissolved in the electrolyte to form a ″shuttle effect″. In view of the above shortcomings，a sulfur host by lithium salt modified rectorite and a carbon-sulfur composite cathode material were designed to improve the electrochemical performance of lithiumsulfur batteries. It has been tested that the lithium salt modification can dredge the interlayer and pore structure of the rectorite to a large extent，increase the specific surface area and pore volume，thereby expanding the loading space of sulfur in the pores，and at the same time enriching lithium ions in a large amount. The material can effectively improve the transport of ions and electrons in charge and discharge. The modified positive electrode composite has a charge-discharge specific capacity of 877 mAh/g in the first cycle at 0. 1 C，and the specific capacity decay to 653 mAh/g after 60 cycles，and the capacity retention rate is 74. 5%，indicating that the components in the material can effectively adsorb polysulfide. The components inhibit the shuttle effect and makes the material have better cycle stability. The average specific capacities at current densities of 0. 1，0. 2，0. 5，1 C are 850，750，600，500 mAh/g，respectively，and show good rate performance. Its charge transfer impedance is 63 Ω， which is conducive to the conduction of electronic charges.

Key words: lithium-sulfur battery, rectorite, lithium salt modification, electrochemical performance