Core–shell polyoxometalate-based zeolite imidazole framework-derived multi-interfacial MoSe2/CoSe2@NC enabling multi-functional polysulfide anchoring and conversion in lithium–sulfur batteries,Journal of Materials Chemistry A

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Core–shell polyoxometalate-based zeolite imidazole framework-derived multi-interfacial MoSe2/CoSe2@NC enabling multi-functional polysulfide anchoring and conversion in lithium–sulfur batteries
Journal of Materials Chemistry A ( IF 10.7 ) Pub Date : 2022-12-29 , DOI: 10.1039/d2ta08292f
Lunan Zhang ₁ , Tangsuo Li ₁ , Xuecheng Zhang ₁ , Zhiyuan Ma ₁ , Qiuping Zhou ₁ , Yi Liu ₁ , Xinyuan Jiang ₁ , Hangyu Zhang ₁ , Lubin Ni ₁ , Guowang Diao ₁

Affiliation

The realistic application of lithium–sulfur batteries (LSBs) as a competitive candidate for next-generation electrochemical energy storage systems is still hampered by the severe polysulfide shuttle effect and sluggish redox kinetics. Designing multi-functional host materials for a cathode that takes into account both adsorption ability to the polysulfide and bidirectional acceleration for sulfur conversion is crucial for the deployment of LSBs. Herein, for the first time, core–shell MoSe₂/CoSe₂@NC are proposed to effectively adsorb soluble polysulfides and simultaneously manipulate the kinetics during charging and discharging. Such cathode host material is derived from a polyoxometalate (POM)-based ZIF as the precursor, and the abundant MoSe₂/CoSe₂ heterojunction structures are embedded in the conductive N-doped carbon polyhedron skeleton. Adsorption test, Li₂S oxidation test and density functional theory (DFT) simulation results collectively demonstrate that CoSe₂ has a chemical adsorption effect on polysulfides, and can catalyze the reduction reaction of long-chain polysulfides, while MoSe₂ possesses the bidirectional conversion catalytic activities on sulfur, particularly the oxidation reaction of short-chain polysulfides. Furthermore, in situ UV-vis experiments indicate that MoSe₂ can greatly promote the generation of S₃˙⁻ radicals, which is beneficial for the polysulfide conversion. Benefiting from the excellent characteristics of each component in the heterostructures, the S@MoSe₂/CoSe₂@NC electrode with the sulfur loading of 1.5 mg cm⁻² exhibits a high initial capacity of 1352.54 mA h g⁻¹ and satisfactory cycling stability (low average capacity attenuation of 0.075% in 500 cycles at the high rate of 3C). More encouragingly, it also exhibits good battery performance even at a high sulfur loading of 3.6 mg cm⁻². This study offers a deeper insight into the fabrication of transition metal selenide (TMSe)-based heterostructures for designing multi-functional cathode materials for LSBs.

中文翻译：

基于核壳多金属氧酸盐的沸石咪唑骨架衍生的多界面MoSe2/CoSe2@NC可在锂硫电池中实现多功能多硫化物锚定和转化

锂硫电池 (LSB) 作为下一代电化学储能系统的竞争候选者的实际应用仍然受到严重的多硫化物穿梭效应和缓慢的氧化还原动力学的阻碍。设计用于阴极的多功能主体材料，同时考虑到对多硫化物的吸附能力和硫转化的双向加速对于 LSB 的部署至关重要。在此，首次提出了核-壳 MoSe ₂ /CoSe ₂ @NC 以有效吸附可溶性多硫化物并同时控制充电和放电过程中的动力学。这种阴极主体材料来源于多金属氧酸盐 (POM) 基 ZIF 作为前驱体，以及丰富的 MoSe ₂ /CoSe_2个异质结结构嵌入导电的N掺杂碳多面体骨架中。吸附试验、Li₂ S氧化试验和密度泛函理论（DFT）模拟结果共同表明CoSe₂对多硫化物具有化学吸附作用，可催化长链多硫化物的还原反应，而MoSe₂具有双向转化催化作用对硫的活性，特别是短链多硫化物的氧化反应。此外，原位紫外-可见实验表明，MoSe₂可以极大地促进S₃ ˙^−的生成自由基，有利于多硫化物的转化。得益于异质结构中各组分的优异特性，硫负载量为1.5 mg cm ^-2的S@MoSe₂ /CoSe ₂ @NC电极表现出1352.54 mA hg ^-1的高初始容量和令人满意的循环稳定性（低3C高倍率500次循环平均容量衰减0.075%）。^{更令人鼓舞的是，即使在 3.6 mg cm -2}的高硫负载下，它也表现出良好的电池性能。本研究对基于过渡金属硒化物 (TMSe) 的异质结构的制造提供了更深入的了解，以设计用于 LSB 的多功能阴极材料。

更新日期：2022-12-29

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