MoP QDs@graphene as highly efficient electrocatalyst for polysulfide conversion in Li-S batteries
| Autor: | Katam Srinivas, Fei Ma, Dongjiang Chen, Bin Wang, Xinqiang Wang, Bo Yu, Wanli Zhang, Zegao Wang, Xiaojuan Zhang, Weidong He, Yuanfu Chen |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Polymers and Plastics chemistry.chemical_element 02 engineering and technology 010402 general chemistry Electrocatalyst Electrochemistry 01 natural sciences Redox law.invention Electron transfer chemistry.chemical_compound law Materials Chemistry Polysulfide Graphene Mechanical Engineering Metals and Alloys 021001 nanoscience & nanotechnology 0104 chemical sciences Chemical engineering chemistry Mechanics of Materials Quantum dot Ceramics and Composites Lithium 0210 nano-technology |
| Zdroj: | Journal of Materials Science & Technology. 90:37-44 |
| ISSN: | 1005-0302 |
| Popis: | The shuttle effect of lithium polysulfides (LiPSs) and sluggish redox conversion significantly hinder practical implementation of lithium-sulfur batteries (LSBs). To overcome these issues, herein, we present MoP quantum dots anchored N, P-doped graphene (MPQ@G) as a multifunctional LSB cathode. The N, P-doped graphene layers serve as a conductive skeleton to support the MoP QDs which can accelerate the electron transfer, physically hinder the polysulfide migration and thus enhance the electrochemical performance. More importantly, as a polar and conductive catalyst, MoP QDs provide catalytically active sites for the conversion of LiPSs. As a result, the LSBs with MPQ@G/S cathodes deliver an elevated initial capacity of 1220.2 mAh g−1 at 0.2 C and remain 98.9% after rate cycles, signifying its exceptional cycling stability. Moreover, it displays a large capacity of 681.2 mAh g−1 even at a high rate of 1 C. The Li-S pouch cell also presents high specific capacities and preeminent cycling stabilities, confirming its great potential for high-rate applications. Density functional theory calculations demonstrate the improved absorptivity and redox conversion reversibility of LiPSs. This work provides an efficient strategy to improve composite with highly adsorptive and catalytic properties for high-performance Li-S batteries. |
| Databáze: | OpenAIRE |
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