| Autor: |
Piao, Ying, Qin, Yan, Ren, Yang, Heald, Steve M., Sun, Chengjun, Zhou, Dehua, Polzin, Bryant J., Trask, Steve E., Amine, Khalil, Wei, Yinjin, Chen, Gang, Bloom, Ira, Chen, Zonghai |
| Zdroj: |
Physical Chemistry Chemical Physics (PCCP); 2014, Vol. 16 Issue 7, p3254-3260, 7p |
| Abstrakt: |
Evolving factor analysis (EFA) of X-ray absorption near-edge spectroscopy (XANES) data is shown to be a useful tool to understand the phase relationships and compositional ranges of stability in the LiVPO4F–VPO4F system. EFA was used to calculate the concentration of phases versus state-of-charge in a lithium-ion battery and true XANES spectra. The results of EFA showed that, indeed, three phases were present during cycling of a LiVPO4FLi cell: LiVPO4F, LixVPO4F, and VPO4F. In contrast to what was reported by others, the second phase was not a fixed composition with x = 0.67, but, instead, existed over a range of lithium stoichiometry, x = 0.25 to 0.80. EFA results also showed that the reactions leading to these phases are reversible. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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