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Controlled-Size Hollow Magnesium Sulfide Nanocrystals Anchored on Graphene for Advanced Lithium Storage
ACS Nano ( IF 15.8 ) Pub Date : 2018-11-28 00:00:00 , DOI: 10.1021/acsnano.8b07770
Baoping Zhang 1 , Guanglin Xia 1 , Wei Chen 1 , Qinfen Gu 2 , Dalin Sun 1 , Xuebin Yu 1
Affiliation  

Magnesium sulfide (MgS), representative of alkaline-earth metal chalcogenides (AEMCs), is a potential conversion/alloy-type electrode material for lithium ion batteries (LIBs), by virtue of its low potential, high theoretical capacity, and abundant magnesium resource. However, the limited capacity utilization and inferior rate performance still hinder its practical application, and the progress is rather slow due to the challenging fabrication technique for MgS. Herein, we report a series of controlled-size hollow MgS nanocrystals (NCs) homogeneously distributed on graphene ([email protected]), fabricated through a metal hydride framework (MHF) strategy, and its application as advanced electrode material for LIBs. The hollow structure of MgS NCs is mainly attributed to the Kirkendall effect and the escape of hydrogen atoms from metal hydride during sulfuration. The as-synthesized [email protected] demonstrates robust nanoarchitecture and admirable interactions, which ensure a spatially confined lithiation/delithiation process, optimize the dynamics of two-steps conversion/alloying reactions, and induce a synergetic pseudocapacitive storage contribution. As a result, a representative [email protected] composite delivers a largely enhanced capacity of >1208 mAh g–1 at a current density of 100 mA g–1 and a long-term cycle stability at a high current density of 5 A g–1 with a capacity of 838 mAh g–1 over 3000 cycles, indicating well-sustained structural integrity. This work presents an effective route toward the development of high-performance magnesium-based material for energy storage.

中文翻译:

固定在石墨烯上的可控尺寸空心硫化镁纳米晶体用于高级锂存储

代表碱土金属硫属元素化物(AEMCs)的硫化镁(MgS)由于其低电势,高理论容量和丰富的镁资源而成为锂离子电池(LIB)的电势转换/合金型电极材料。但是,有限的容量利用率和较差的速率性能仍然阻碍了其实际应用,并且由于具有挑战性的MgS制造技术,进展相当缓慢。在本文中,我们报告了一系列通过金属氢化物骨架(MHF)策略制造的均匀分布在石墨烯上的可控尺寸的中空MgS纳米晶体(NC),并将其用作LIB的高级电极材料。MgS NCs的中空结构主要归因于Kirkendall效应以及硫化过程中氢原子从金属氢化物中逸出。合成后的[受电子邮件保护]展示了强大的纳米体系结构和令人钦佩的交互作用,可确保在空间上限制锂化/脱锂过程,优化两步转化/合金化反应的动力学,并诱导协同伪电容存储。因此,具有代表性的[受电子邮件保护的]复合材料可提供大大增强的容量,> 1208 mAh g 并引起协同伪电容存储贡献。因此,具有代表性的[受电子邮件保护的]复合材料可提供大大增强的容量,> 1208 mAh g 并引起协同伪电容存储贡献。结果,具有代表性的[受电子邮件保护的]复合材料可提供大大增强的容量,> 1208 mAh g–1在100 mA g –1的电流密度下具有很高的长期循环稳定性,在5 A g –1的高电流密度下具有838 mAh g –1的容量,在3000个循环内,表明结构完整性良好。这项工作为开发高性能镁基储能材料提供了一条有效途径。
更新日期:2018-11-28
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