用于稳定锂硫电池的金属有机骨架衍生氧化镁@碳中间层,ACS Sustainable Chemistry & Engineering

当前位置： X-MOL 学术 › ACS Sustain. Chem. Eng. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

用于稳定锂硫电池的金属有机骨架衍生氧化镁@碳中间层
ACS Sustainable Chemistry & Engineering ( IF 7.1 ) Pub Date : 2023-01-19 , DOI: 10.1021/acssuschemeng.2c05064
Hyeonmuk Kang ₁ , Jaewook Shin ₂ , Tae-Hee Kim ₁ , Yongju Lee ₁ , Daehee Lee ₁ , Junho Lee ₁ , Gyungtae Kim ₃ , EunAe Cho ₁

Affiliation

锂硫 (Li-S) 电池代表了未来充满希望的电池技术。然而，固态硫物种（S、Li ₂ S ₂和 Li ₂S)和多硫化物穿梭效应降低了它们的实际容量和循环保留。在此，我们提出了用于 Li-S 电池的由氧化镁 (MgO) 纳米粒子和碳基质组成的夹层。在复合材料中，MgO 可以捕获溶解的多硫化物，这些多硫化物沿着氧化物表面扩散到碳基体中，用于进一步的还原反应。作为生产复合结构的新型前驱体，采用镁金属有机骨架 Mg-MOF-74 并在独立碳纸（MOF/C 纸）上合成。通过热解，Mg-MOF-74 被转化为含有均匀分布的 MgO 纳米粒子的高度多孔碳（MgO@C/C-纸）。用 MgO@C/C-paper 和 C-paper 中间层组装的 Li-S 电池显示出明显更高的初始容量（980 和 898 mAh g ^–1，分别）比无夹层电池（729 mAh g ^–1）由于导电夹层。在 0.2 C 下循环 200 次后，MgO@C/C-纸电池的循环保持率 (78.3%) 优于 C-纸电池 (76.5%)。^{在 3.3 mg cm –2}的更高硫负载下，MgO@C/C-纸电池在 100 次循环后表现出比 C-纸电池 (54.6%) 更高的容量保持率 (80.1%)。MgO@C/C-paper 电池优于 C-paper 电池的出色循环稳定性表明，MOF 衍生的 MgO@C 的独特结构在锚定和再利用溶解的多硫化物方面非常有效。

"点击查看英文标题和摘要"

Metal–Organic Framework-Derived Magnesium Oxide@Carbon Interlayer for Stable Lithium–Sulfur Batteries

Lithium sulfur (Li–S) batteries represent a promising future battery technology. However, the low electrical conductivity of solid-state sulfur species (S, Li₂S₂, and Li₂S) and the polysulfide shuttle effect deteriorate their practical capacity and cycling retention. Herein, we present an interlayer composed of magnesium oxide (MgO) nanoparticles and carbon matrix for the Li–S batteries. In the composite, MgO can capture dissolved polysulfides that diffuse to the carbon matrix along the oxide surface for further reduction reactions. As a novel precursor to produce the composite structure, a Mg metal–organic-framework, Mg-MOF-74, is adopted and synthesized on a free-standing carbon paper (MOF/C-paper). Through pyrolysis, Mg-MOF-74 is converted into highly porous carbon containing uniformly distributed MgO nanoparticles (MgO@C/C-paper). The Li–S cells assembled with MgO@C/C-paper and C-paper interlayer show significantly higher initial capacities (980 and 898 mAh g^–1, respectively) than the interlayer-free cell (729 mAh g^–1) owing to the conductive interlayers. After 200 cycles at 0.2 C, the MgO@C/C-paper cell presents a cycle retention (78.3%) superior to that of the C-paper cell (76.5%). With a higher sulfur loading of 3.3 mg cm^–2, the MgO@C/C-paper cell exhibits an even higher capacity retention (80.1%) than the C-paper cell (54.6%) after 100 cycles. The excellent cycle stability of the MgO@C/C-paper cell over the C-paper cell demonstrates that the unique structure of the MOF-derived MgO@C is highly effective in anchoring and reutilizing dissolved polysulfides.

更新日期：2023-01-19

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南