S/MCNT/Fe3O4正极材料制备及电化学性能研究

锂硫电池因具备高的理论能量密度而引起研究者的广泛关注，但是其实际能量密度仍受限于硫的低电导率及其中间产物多硫化物的“穿梭效应”等因素。为解决以上问题，通过熔硫法将正极活性物质硫负载于多壁碳纳米管的多孔网络骨架中，进一步通过研磨法将其与极性氧化物四氧化三铁复合，制得硫/多壁碳纳米管/四氧化三铁（S/MCNT/Fe₃O₄）正极材料。基于该正极材料组装的锂硫电池，在1C倍率下具有高达908.6 mA·h/g的初始放电比容量，循环250圈后每圈容量衰减率为0.2%，平均库伦效率约为99%，当倍率提高到3C时仍具有636.5 mA·h/g的比容量，表现出优良的倍率性能。

Study on preparation and electrochemical performance of S/MCNT/Fe3O4 cathode materials

Lithium?sulfur battery has attracted extensive attention from researchers due to the high theoretical energy density，but the actual energy density is still limited by the low conductivity of sulfur and the shuttle effect of the intermediate polysulfides，etc.To solve these issues，herein sulfur was loaded onto multi?walled carbon nanotube with the porous framework formed through sulfur melting method，followed by compounding it with the polar oxide ferroferric oxide via grinding method to finally obtain the as?prepared sulfur/multi?walled carbon nanotube/ferroferric oxide（S/MCNT/Fe₃O₄） cathode materials.The lithium sulfur battery assembled based on this cathode material had an initial discharge specific capacity of up to 908.6 mA·h/g at 1C rate.After 250 cycles，the capacity decay rate per cycle was 0.2% and the average coulomb efficiency was about 99%.When the current density was increased to 3C，it still had a capacity of 636.5 mA·h/g，exhibiting excellent rate performance.