ZIF-67衍生Co-NC多孔碳材料的可控制备及其在锂-硫二次电池中的应用研究

以ZIF-67为模板制备了一系列具有不同金属Co负载量的S/Co-NC复合材料, 并将其应用于锂-硫电池正极中进行电化学性能研究。采用扫描电镜(SEM)和透射电镜(TEM)对Co-NC材料的多面体形貌及多孔结构进行表征; 采用X射线衍射(XRD)分析了Co-NC中金属Co的结晶状态; 采用氮气吸脱附方法分析了Co-NC材料的比表面积及孔结构。研究表明, 当刻蚀时间为48 h, 即Co含量为15.93wt%时, 复合硫正极呈现出最佳的循环性能以及倍率性能, 在0.2C电流密度下从第50圈到200圈循环的容量保持率为94.84%, 5.0C高倍率下的放电比容量为718.8 mAh?g ^-1。

Controllable Preparation of Co-NC Nanoporous Carbon Derived from ZIF-67 for Advanced Lithium-sulfur Batteries

This work reported a facile strategy for preparing S/Co-NC composite sulfur cathode materials with different Co loadings derived from ZIF-67, which were applied as cathode materials for Li-S batteries. SEM and TEM were used to observe the morphology and pore structure of Co-NC composite. XRD analysis was employed to investigate the crystalline state of cobalt embedded in porous carbon materials. N₂ adsorption-desorption techniques was used to characterize the BET surface area and pore volume of Co-NC samples. Experimental results showed that the Co-NC with Co content of 15.93wt% exhibited the superior electrochemical performance. The cathode equipped with optimized composite showed a high capacity retention rate of 94.84% between 50 ^th to 200 ^th cycles at 0.2C current density, and even at high current density (5.0C), a high discharge capacity of 718.8 mAh?g ^-1 could still be obtained.