锂硫电池三维石墨烯/硫复合正极材料的制备及其性能

摘要

Three-dimensional graphene/sulfur (3DG/S) binary composite cathode materials are prepared by modified Hummers method, hydrothermal reduction and melting sublimation method using natural graphite powder as precursors. 3DG/S composite cathode materials are characterized by SEM and the electrochemical test. SEM results show that graphene has a three-dimensional porous structure, which can effectively inprove the utilization of the active substance sulfur, and the sulfur evenly distributes in the composites with no reunion pheDIAO Yu, TANG Hou-rui , LV Pengosites can deliver the highest discharge capacity of 800mAh/g in C/8 current density at the first cycle, keeping 600mAh/g after 40 cycles of charge-discharge, and indicated that 3DG/S composite cathode materials have the excellent cycle and rate performance.%以天然石墨粉为原料，采用改进的Hummers法制备氧化石墨烯，再通过水热还原、熔融升华法制备得到三维石墨烯/硫二元复合正极材料。对三维石墨烯/硫复合正极材料进行微观形貌和电化学性能的表征，结果显示：石墨烯具有三维多孔网状结构，能有效增加活性物质硫的利用率，并且硫均匀地负载在三维石墨烯的孔道和表面，没有发生团聚现象；电化学性能结果显示：三维石墨烯/硫复合正极材料在C/8电流密度下首次充放电容量为800mAh/g，40周次循环后容量还保持在600mAh/g左右，表明三维石墨烯/硫复合正极材料具有优异的循环与倍率性能。