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For reducing carbon emission and alleviating pollution, people are gradually replacing the fossil fuel-employing combustion engines with new energy devices. The secondary batteries with high energy storage have become a hot alternative to power sources due to its zero emission during their operation. In recent years, as the most popular energy storage equipment in the battery market for mobile devices, lithium-ion battery is gradually showing a decline in the field of power battery, because its energy density (~ 150 Wh kg-1 ) has been unable to meet the demands of power equipment, and the current research has almost reached the theoretical capacity of lithium-ion battery electrode materials, and leaves little space for improvement. Therefore, academic research began to seek a variety of new battery systems to meet the needs of the industry. As a battery system based on the non-topological reaction between lithium anode and sulfur anode, lithium sulfur battery has a very high theoretical energy density (2567 Wh kg-1 ) and theoretical specific capacity (1672 mAh g -1 ), which is good enough to meet the energy density requirements (500-600 Wh kg-1 ) of power battery. Meanwhile, sulfur is of low cost and environmentally friendly, which is suitable for large-scale commercialization. Therefore, it is considered as a strong competitor of the next generation power supply. However, a series of shortcomings of lithium sulfur battery limit its large-scale application at present stage; for examples, the sluggish reaction kinetics of active sulfur and the degraded cyclic stability from shuttle effect. The improvement of both can ameliorate the rate performance and cycle stability of lithium sulfur battery, which are crucial to the practical application of power battery. In this thesis, in order to solve the above problems, the author first used a facile and scalable method to prepare carbon black/ PEDOT:PSS. The modified separator was applied to lithium sulfur battery as an improved interlayer of the cathode. The principle of improving sulfur cathode by the interlayer was studied by the electrochemical analysis. The high conductivity and polysulfide adsorption ability of the coating delivers an initial specific capacity of 1315 mAh g -1 at 0.2 C current, and 699 mAh g -1 at a high rate of 2 C current; secondly, for the purpose of reducing the density of the cathode interlayer, a threedimensional graphene foam was chosen as the conductive substrate of the interlayer, and modified with the zinc oxide by atomic layer deposition (ALD), creating the self-standing three-dimensional graphene foam / nano zinc oxide interlayer. This interlayer leads to an initial specific capacity of 1051 mAh g -1 at a 0.5 C rate. Its low area density (0.15 mg cm-2 ) also reduces the influence on the energy density of the cathode. As a step forward, the two-dimensional Ti3C2Tx nanosheet (MXene) with high conductivity and polysulfide adsorption characteristics was selected as an alternative material of zinc oxide to modify the graphene foam (GFMX), which simplifies the synthesis process and enhances the electronic conductivity of the interlayer. After 120 cycles at 0.2 C, the lithium sulfur batteries still maintain a specific capacity of 867 mAh g -1 and 755 mAh g -1 at 2 C high rate current with the GFMX interlayer. In light of the significant improvement of the interlayer by MXene, the modified the MXene by an in-situ growth of nitrogen and nickel doped carbon nanosheets has been studied. Results show that the stacking of MXene is greatly reduced and the specific surface area of the material is increased, moreover, the adsorption capacity of polysulfides has been largely improved by the nitrogen doping. When using the obtained composite material as the separator coating, the lithium sulfur batteries exhibit 943 mAh g -1 specific capacity after 100 cycles at 0.2 C current, and 588 mAh g -1 specific capacity after 500 cycles at 1 C. The average cycle capacity decay rate is 0.069%, and the specific capacity of the high sulfur loading cathode (3.8 mg cm-2 ) is 946 mAh g -1 , highlighting its potential applications in the high-performance lithium sulfur batteries.