Synthesis and electrochemical properties of 4LiF-NiMn 2 O 4 composite as a cathode material for Li-ion batteries
| Autor: | Yasumasa Tomita, Yoshiumi Kohno, Juichi Arai, Noritaka Kimura, Yusuke Izumi, Kenkichiro Kobayashi |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Renewable Energy Sustainability and the Environment Composite number Analytical chemistry Energy Engineering and Power Technology 02 engineering and technology Electrolyte 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences Decomposition 0104 chemical sciences Ion X-ray photoelectron spectroscopy Cathode material Electrical and Electronic Engineering Physical and Theoretical Chemistry 0210 nano-technology Voltage |
| Zdroj: | Journal of Power Sources. 354:34-40 |
| ISSN: | 0378-7753 |
| DOI: | 10.1016/j.jpowsour.2017.04.003 |
| Popis: | 4LiF-NiMn 2 O 4 composites are synthesized by the mechanical milling of LiF and NiMn 2 O 4 in a molar ratio of 4: 1 for 36–192 h. The synthesized composites are investigated by XRD, charge-discharge measurements, and XPS. A broad XRD peak of 4LiF-NiMn 2 O 4 was observed and those of LiF and NiMn 2 O 4 disappear after the milling of 144 h and more. The discharge capacity of the 4LiF-NiMn 2 O 4 composites changes with the milling time, with the composite prepared by milling for 144 h exhibiting a discharge capacity of 256 mA h g −1 at 0.1 C for voltages of 2.0–4.8 V. With a cut-off voltage of 4.8 V or more, decomposition of the electrolyte proceeds along with the charge process, so the charge-discharge current efficiency deteriorates and the discharge voltage decreases. In the charge-discharge measurement without the capacity limit, although the charge-discharge efficiency was low due to the decomposition of the electrolyte, the high discharge capacity of 310 mA h g −1 was obtained. The XPS data suggests that the Ni 2+ ion and Mn 3+ ion are oxidized to Ni 3+ and Mn 4+ ion in charge process up to 4.8 V and are reduced to Ni 2+ ion and Mn 3+ ion during the discharge process. |
| Databáze: | OpenAIRE |
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