ZIFs衍生多孔炭-金属硫化物复合材料的制备及在锂硫电池中的应用

Preparation and application of porous carbon-metal sulfide composites derived from ZIFs in lithium-sulfur batteries

锂硫电池因具有成本低和能量密度高等优点而受到广泛关注,但由于中间产物的溶解而产生致命的穿梭效应,严重缩短了电池的循环寿命。本文以ZIF-8为前驱体,经炭化后再硫化得到ZIFs衍生多孔炭-硫化锌复合材料(ZnS-ZDPC)。结果表明,ZnS-ZDPC/S为正极的Li-S电池在放电倍率为0.2C时,首次放电比容量为1 265.2 mA·h·g^-1,循环300次后仍然能保持在654.1 m A·h·g^-1,相比于ZDPC/S电极材料,容量衰减较慢,表现出较好的电化学性能。

Lithium-sulfur battery has attracted much attention because of its low cost and high energy density. However, lithium sulfur batteries suffer from the fatal shuttle effect caused by intermediate dissolution during cycling, significantly shortening their cycle life. In this paper, using ZIF-8 as the precursor, ZIFs-derived porous carbon-zinc sulfide composites(ZnS-ZDPC) are prepared by carbonization and subsequent sulfuration. The results show that the ZnS-ZDPC/S electrode exhibits the discharge specific capacity of 1 265.2 m A·h·g^-1, and remains at 654.1 mA·h·g^-1 after 300 cycles at 0.2 C. Compared with the ZDPC/S electrode, the ZnS-ZDPC/S electrode has slower capacity decay, and exhibits better electrochemical performance.