On the mechanistic role of nitrogen-doped carbon cathodes in lithium-sulfur batteries with low electrolyte weight portion
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
The lithium-sulfur (Li–S) battery is a promising alternative to overcome capacity and specific energy limitations of common lithium-ion batteries. Highly porous, nitrogen-doped carbons as conductive host structures for sulfur/lithium sulfide deposition are shown herein to play a critical role in reversible cycling at low electrolyte/sulfur ratio. The pore geometry is precisely controlled by an efficient, scalable ZnO hard templating process. By using an electrolyte volume as low as 4 µL mg-1 S, the beneficial nitrogen functionality leads to a twofold increased cell lifetime turning our findings highly favorable for real applications. Stable cycling of up to 156 cycles (59 cycles with undoped carbon) with high sulfur loadings of 3 mg cm-2 is achieved. Operando X-ray diffraction measurements during cycling show the transformation pathway of the sulfur – polysulfide – Li2S species. The observed intermediates critically depend on the nitrogen doping in the cathode carbon matrix. Nitrogen-doped carbons facilitate polysulfide adsorption promoting the nucleation of crystalline Li2S. These results provide new insights into the significant role of heteroatom doping for carbons in Li-S batteries with high specific energy.
Details
Original language | English |
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Pages (from-to) | 116-128 |
Number of pages | 13 |
Journal | Nano energy |
Volume | 54 |
Publication status | Published - Dec 2018 |
Peer-reviewed | Yes |
Keywords
Sustainable Development Goals
ASJC Scopus subject areas
Keywords
- Cathode, Conversion mechanism, Lithium-sulfur battery, Nitrogen-doped carbon, Operando diffraction