Cu-Mo Bimetal Modulated Multifunctional Carbon Nanofibers Promoting the Polysulfides Conversion for High-Sulfur-Loading Lithium-Sulfur Batteries
Cu-Mo Bimetal Modulated Multifunctional Carbon Nanofibers Promoting the Polysulfides Conversion for High-Sulfur-Loading Lithium-Sulfur Batteries
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DOI：
10.1021/acsami.2c13012
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发表时间：
2022-10-12
影响因子：
9.5
通讯作者：
Zhang, Zhangjing
中科院分区：
文献类型：
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作者：
Cheng, Zhibin;Pan, Hui;Zhang, Zhangjing
高硫负载对于实现高能量密度锂硫（Li-S）电池至关重要。然而，在增加独立式正极的硫负载量时，暴露出硫利用率低、循环稳定性差、倍率性能低等严重问题。为了解决这些问题，必须提高高硫负载量阴极对多硫化物的吸附/催化能力。在此，基于阳离子MOF的优异性能，我们提出可以通过阳离子MOF的简易MoO42-阴离子交换来制备嵌入具有高效催化位点的多功能自支撑氮掺杂多孔碳纳米纤维（Cu-Mo@NPCN）的Cu-Mo双金属纳米颗粒。而且，嵌入Cu-Mo@NPCN中的硫直接用作自支撑电极，即使在高硫负载下也能实现高面积容量、良好的倍率性能和良好的循环稳定性。独立式 Cu-Mo@ NPCN/10.3S 阴极在 0.2 C 下实现了 1163 mA h cm-3 的高体积容量和 9.3 mA h cm-2 的面积容量，硫负载量为 10.3 mg cm-2。这项工作为设计独立式硫阴极提供了一种创新方法，并将推动各种储能系统中阳离子 MOF 衍生双金属催化剂的开发。
High sulfur loading is essential for achieving high energy density lithium-sulfur (Li-S) batteries. However, serious issues such as low sulfur utilization, poor cycling stability, and sluggish rate performance have been exposed when increasing the sulfur loading for freestanding cathodes. To solve these problems, the adsorption/catalytic ability of high-sulfur-loading cathode toward polysulfides must be improved. Herein, based on excellent properties of cationic MOFs, we proposed that Cu-Mo bimetallic nanoparticles embedded in multifunctional freestanding nitrogen-doped porous carbon nanofibers (Cu-Mo@NPCN) with efficient catalytic sites could be prepared by facile MoO42- anion exchange of cationic MOFs. And, the sulfur embedded in Cu-Mo@NPCN was directly used as self-supporting electrodes, enabling a high areal capacity, good rate performance, and decent cycling stability even under high sulfur loading. The freestanding Cu-Mo@ NPCN/10.3S cathode achieves a high volumetric capacity of 1163 mA h cm-3 and a decent areal capacity of 9.3 mA h cm-2 at 0.2 C with a sulfur loading of 10.3 mg cm-2. This work provides an innovative approach for engineering a freestanding sulfur cathode and would forward the development of cationic MOF-derived bimetallic catalysts in various energy storage systems.