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High rate and long cycle life in Li-O2 batteries with highly efficient catalytic cathode configured with Co3O4 nanoflower
- Source :
- Nano Energy. 64:103896
- Publication Year :
- 2019
- Publisher :
- Elsevier BV, 2019.
-
Abstract
- The reaction mechanism of non-aqueous Li-O2 batteries is based on the deposition and decomposition of Li2O2. The polarization of Li-O2 batteries can be rapidly increased by operation under a high rate condition, resulting in the early capacity fade of the cells. Therefore, a well-designed catalyst with a unique structure and excellent catalytic ability is an important way to boost the round-trip performance of Li-O2 batteries, especially under high current density. In this work, a unique nanoflower structure assembled with Co3O4 nanosheets is synthesized by using 2-methylimidazole (2-MIM) as a structural directing agent. X-ray photoelectron spectroscopy (XPS) and Raman spectra reveal abundant oxygen vacancies on the surface of the Co3O4 nanoflower, which are beneficial for oxygen reduction and evolution reactions and long round-trip lifetime. Density functional theory results demonstrate that Co3O4 catalyst with oxygen vacancies could promote the wetting of Li2O2 on substrate and formation of a Li2O2 nanofilm, thereby boosting the discharge capacity of Li-O2 batteries. On account of the synergistic effect of abundant oxygen vacancies, the unique structure, and excellent oxygen evolution reaction, Co3O4 nanoflower-based cells could deliver ultralong lifetime of 276 and 248 cycles with a discharge capacity of 1000 mAh g−1 under charge/discharge current densities of 0.5 A g−1 and 1 A g−1, respectively. This study has shed light on a new strategy for catalyst preparation for long lifetime Li-O2 batteries.
- Subjects :
- Reaction mechanism
Materials science
Renewable Energy, Sustainability and the Environment
Oxygen evolution
chemistry.chemical_element
02 engineering and technology
Nanoflower
010402 general chemistry
021001 nanoscience & nanotechnology
01 natural sciences
Oxygen
Cathode
0104 chemical sciences
Catalysis
law.invention
X-ray photoelectron spectroscopy
Chemical engineering
chemistry
law
General Materials Science
Electrical and Electronic Engineering
0210 nano-technology
Polarization (electrochemistry)
Subjects
Details
- ISSN :
- 22112855
- Volume :
- 64
- Database :
- OpenAIRE
- Journal :
- Nano Energy
- Accession number :
- edsair.doi...........eb2b4c509e4f09ba01fed797f6200650