Abstract
Lithium-sulfur batteries with high energy capacity are promising candidates for advanced energy storage. However, their applications are impeded by shuttling of soluble polysulfides and sluggish conversion kinetics with inferior rate performance and short cycling life. Here, single-atom materials are designed to accelerate polysulfide conversion for Li-S batteries. Nitrogen sites in the structure not only anchor polysulfides to alleviate the shuttle effect but also enable high loading of single-atom irons. Density functional theory calculations indicate that single-atom sites reduce the energy barrier of electrochemical reactions and thus improve the rate and cycling performances of batteries. The coin battery shows impressive energy storage properties, including a high reversible capacity of 1379 mAh g-1 at 0.1 C and a high rate capacity of 704 mAh g-1 at 5 C. The ratio of electrolyte dosage/energy density is as low as 5.5 g Ah1-. It exhibits excellent cycling performance with a capacity retention of 90% even after 200 cycles at 0.2 C. © 2020 American Chemical Society.
Original language | English |
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Pages (from-to) | 5522-5530 |
Number of pages | 9 |
Journal | Nano Letters |
Volume | 20 |
Issue number | 7 |
Early online date | 24 Jun 2020 |
DOIs | |
Publication status | Published - 8 Jul 2020 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2020 American Chemical Society.
Funding
This work was supported by the Earth Engineering Center, Center for Advanced Materials for Energy and Environment at Columbia University, and by startup funding from Columbia University.
Keywords
- Fast polysulfide kinetics
- Lean-electrolyte
- Lithium-sulfur batteries
- Long cyclic life
- Single-atom materials