Novel insights into higher capacity from the Li-ion battery cathode material Li 2 FeSiO 4
| Autor: | Anti Liivat, Yong Yang, Josh Thomas, Jianghuai Guo |
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| Rok vydání: | 2017 |
| Předmět: |
Auxiliary electrode
Working electrode Chemistry General Chemical Engineering Inorganic chemistry Analytical chemistry 02 engineering and technology Electrolyte 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Redox 0104 chemical sciences Ion Oxidation state Formula unit Electrode Electrochemistry 0210 nano-technology |
| Zdroj: | Electrochimica Acta. 223:109-114 |
| ISSN: | 0013-4686 |
| DOI: | 10.1016/j.electacta.2016.12.008 |
| Popis: | A highly reactive composite cathode material incorporating nano-particles of the popular Li-ion battery cathode material Li 2 FeSiO 4 (LFS) is here studied to probe the activation of the controversial Fe 3+ /Fe 4+ redox couple in exploiting the second Li-ion in the formula unit – for use in rechargeable Li-ion batteries. A novel form of in situ Mossbauer spectroscopy is used to monitor the oxidation state of the Fe-ions in symmetric LFS || LFS cells. This is based on mapping the poorly resolvable Mossbauer spectra from the expected Fe 3+ /Fe 4+ redox couple in the working electrode onto the highly resolvable Fe 2+ /Fe 3+ spectra from the counter electrode. Comparison of such data from half-delithiated Li(1)Fe 3+ SiO 4 || Li(1)Fe 3+ SiO 4 and almost lithium-free “Li(0)Fe 4+ SiO 4 || Li(0)Fe 4+ SiO 4 ” symmetric cells is demonstrated – to distinguish the electrode reactions from the those involving the electrolyte. Lithium is shown to cycle reversibly in the symmetric cells. However, a large proportion of the cycled lithium (∼70%) does not derive from the bulk of the electrodes, but is rather a result of high-V electrolyte degradation, where charge balance is maintained by leaching lithium from the electrolyte and inserting it into the electrodes. |
| Databáze: | OpenAIRE |
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