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In Situ Mg/MgO-Embedded Mesoporous Carbon Derived from Magnesium 1,4-Benzenedicarboxylate Metal Organic Framework as Sustainable Li–S Battery Cathode Support
ACS Omega ( IF 3.7 ) Pub Date : 2017-10-06 00:00:00 , DOI: 10.1021/acsomega.7b01156 Tanumoy Dhawa 1 , Shreyasi Chattopadhyay 1 , Goutam De 1 , Sourindra Mahanty 1
ACS Omega ( IF 3.7 ) Pub Date : 2017-10-06 00:00:00 , DOI: 10.1021/acsomega.7b01156 Tanumoy Dhawa 1 , Shreyasi Chattopadhyay 1 , Goutam De 1 , Sourindra Mahanty 1
Affiliation
Development of advanced carbon cathode support with the ability to accommodate high sulfur (S) content as well as effective confinement of the sulfur species during charge–discharge is of great importance for sustenance of Li–S battery. A facile poly(vinylpyrrolidone)-assisted solvothermal method is reported here to prepare Mg–1,4-benzenedicarboxylate metal organic framework (MOF) from which mesoporous carbon is derived by thermal treatment, where the hexagonal sheetlike morphology of the parent MOF is retained. Existence of abundant pores of size 4 and 9 nm extended in three dimensions with zigzag mazelike channels helps trapping of S in the carbon matrix through capillary effect, resulting in high S loading. When tested as a cathode for lithium–sulfur battery, a reversible specific capacity of 1184 mAh g–1 could be achieved at 0.02 C. As evidenced by X-ray photoelectron spectroscopy, in situ generated Mg in the carbon structure enhances the conductivity, whereas MgO provides support to S immobilization through chemical interactions between Mg and sulfur species for surface polarity compensation, restricting the dissolution of polysulfide into the electrolyte, the main cause for the “shuttle phenomenon” and consequent capacity fading. The developed cathode shows good electrochemical stability with reversible capacities of 602 and 328 mAh g–1 at 0.5 and 1.0 C, respectively, with retentions of 64 and 67% after 200 cycles. The simple MOF-derived strategy adopted here would help design new carbon materials for Li–S cathode support.
中文翻译:
1,4-苯二甲酸镁金属有机骨架衍生的原位Mg / MgO嵌入介孔碳作为可持续的Li–S电池阴极支持
能够容纳高硫(S)含量以及在充放电过程中有效限制硫种类的能力的高级碳阴极支架的开发对于维持Li-S电池至关重要。此处报道了一种简便的聚(乙烯基吡咯烷酮)辅助溶剂热法制备Mg-1,4-苯二甲酸金属有机骨架(MOF),通过热处理从中衍生出中孔碳,并保留了母体MOF的六角形片状形态。锯齿状迷宫状通道在三个维度上延伸的尺寸为4和9 nm的大量孔的存在有助于通过毛细作用将S捕集在碳基质中,从而导致高S负载。作为锂硫电池的正极进行测试时,可逆比容量为1184 mAh g –1X射线光电子能谱证明,在碳结构中原位生成的Mg增强了电导率,而MgO通过Mg和硫物种之间的化学相互作用为表面上的极性补偿提供了S固定化的支持,从而限制了多硫化物溶解到电解质中,是造成“穿梭现象”和随之而来的容量衰减的主要原因。发达的阴极显示出良好的电化学稳定性,在0.5和1.0 C时可逆容量分别为602和328 mAh g –1,在200次循环后保留率分别为64%和67%。此处采用的基于MOF的简单策略将有助于设计用于Li-S阴极载体的新型碳材料。
更新日期:2017-10-06
中文翻译:
1,4-苯二甲酸镁金属有机骨架衍生的原位Mg / MgO嵌入介孔碳作为可持续的Li–S电池阴极支持
能够容纳高硫(S)含量以及在充放电过程中有效限制硫种类的能力的高级碳阴极支架的开发对于维持Li-S电池至关重要。此处报道了一种简便的聚(乙烯基吡咯烷酮)辅助溶剂热法制备Mg-1,4-苯二甲酸金属有机骨架(MOF),通过热处理从中衍生出中孔碳,并保留了母体MOF的六角形片状形态。锯齿状迷宫状通道在三个维度上延伸的尺寸为4和9 nm的大量孔的存在有助于通过毛细作用将S捕集在碳基质中,从而导致高S负载。作为锂硫电池的正极进行测试时,可逆比容量为1184 mAh g –1X射线光电子能谱证明,在碳结构中原位生成的Mg增强了电导率,而MgO通过Mg和硫物种之间的化学相互作用为表面上的极性补偿提供了S固定化的支持,从而限制了多硫化物溶解到电解质中,是造成“穿梭现象”和随之而来的容量衰减的主要原因。发达的阴极显示出良好的电化学稳定性,在0.5和1.0 C时可逆容量分别为602和328 mAh g –1,在200次循环后保留率分别为64%和67%。此处采用的基于MOF的简单策略将有助于设计用于Li-S阴极载体的新型碳材料。