Abstract
KGaA, Weinheim It is generally understood that particle-shaped Li2O2is preferred in Li-O2batteries (LOBs) because the dominance of Li2O2films may lead to poor electrochemical performance. The influence of Li2O2morphology and its nucleation mechanism are probed by experiments along with the first-principle calculations. It is revealed that the LOBs with Li2O2films deliver unexpectedly improved capacities, longer cycles, and significantly reduced overpotentials assisted by NiFeOxnanofiber catalysts. The energetically favored Li 2a vacancies under LiO2-rich conditions, small crystallites, and large contact areas with the electrode/electrolyte explain the anomalous performance enhancement. Li2O2films are formed by a heterogeneous nucleation mechanism and the voltage applied, electrolyte, electrode surface, and use of catalysts are identified as the parameters controlling the mechanisms. The mapped correlations among these parameters shed light on the control of Li2O2morphology for developing high-performance LOBs.
Original language | English |
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Pages (from-to) | 8290-8299 |
Number of pages | 10 |
Journal | Advanced Functional Materials |
Volume | 26 |
Issue number | 45 |
DOIs | |
Publication status | Published - 6 Dec 2016 |
Externally published | Yes |
Keywords
- heterogeneous nucleation
- Li O films 2 2
- lithium-oxygen batteries
- morphology control
- oxygen-rich Li O 2 2
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Condensed Matter Physics
- Electrochemistry