摘要
为了提高硫化锂正极的倍率性能、抑制多硫化锂穿梭并降低成本,以三硫化二锂作为硫化锂的前驱体,聚乙烯吡咯烷酮和碳纳米管作为碳源,经高温处理制备纳米硫化锂/碳复合材料,以此作为锂硫电池的正极材料。采用扫描电子显微镜、X射线衍射仪、热重分析仪对该复合材料的形貌、结构以及组成进行表征,并进行电化学性能测试。结果表明:制备的纳米硫化锂/碳复合正极材料中,纳米硫化锂分散均匀并被热分解的碳包覆,合成的三硫化二锂前驱体在空气中具有一定的稳定性,能够降低纳米硫化锂的生产成本;将纳米硫化锂/碳复合正极材料用于锂硫电池时,在0.07 C(1 C=1166 mA/g)倍率下初始放电比容量达910 mAh/g,在1.00 C高倍率下循环150次后,可逆容量保持在484 mAh/g,这表明纳米硫化锂/碳的活性物质利用率较高、多硫化锂穿梭较弱。采用三硫化二锂前驱体制备高性能硫化锂复合材料,工艺成本低,有助于硫化锂正极材料的实际应用。
In order to improve the rate capability of lithium sulfide cathode, inhibit the shuttle of lithium polysulfides and reduce the cost, a nanoscale lithium sulfide/carbon composite material was prepared by using dilithium trisulfide as the precursor of lithium sulfide, polyvinylpyrrolidone and carbon nanotubes as carbon sources under high temperature treatment, which was used as a cathode material for lithium-sulfur batteries. Scanning electron microscope, X-ray diffractometer and thermogravimetric analyzer were used to detect and analyze the morphology, structure and composition of the composites, and its electrochemical performances were tested. The results have shown that in the prepared nano-lithium sulfide/carbon composite cathode material, nano-lithium sulfide was uniformly dispersed and coated by thermally decomposed carbon, and the synthesized lithium trisulfide precursor had certain stability in air, which could reduce the production cost of nano-lithium sulfide;when the nano-sized lithium sulfide/carbon composite were used in lithium-sulfur batteries cathode, an initial discharge specific capacity of 910 mAh/g(1 C=1166 mA/g) at a rate of 0.07 C could be reached, and the reversible discharge specific capacity remained 484 mAh/g after 150 cycles at a high rate of 1.00 C, indicating the improvement of the utilization of active materials and the weak shuttle effect of lithium polysulfides. Using dilithium trisulfide as precursor to prepare high-performance lithium sulfide composite materials has a low process cost and is conducive to the practical application of lithium sulfide cathode materials.
作者
房彬
徐富良
江永明
叶方敏
FANG Bin;XU Fuliang;JIANG Yongming;YE Fangmin(School of Science,Zhejiang Sci-Tech University,Hangzhou 310018,China)
出处
《浙江理工大学学报（自然科学版）》
2023年第1期43-49,共7页
Journal of Zhejiang Sci-Tech University(Natural Sciences)
基金
国家自然科学基金项目(22075313)
浙江理工大学科研启动基金(18062299-Y)。
