High Reversibility of Lattice Oxygen Redox in Na-ion and Li-ion Batteries Quantified by Direct Bulk Probes of both Anionic and Cationic Redox Reactions
| Autor: | Dai, Kehua, Wu, Jinpeng, Zhuo, Zengqing, Li, Qinghao, Sallis, Shawn, Mao, Jing, Ai, Guo, Sun, Chihang, Li, Zaiyuan, Gent, William E., Chueh, William C., Chuang, Yi-de, Zeng, Rong, Shen, Zhi-xun, Pan, Feng, Yan, Shishen, Piper, Louis F. J., Hussain, Zahid, Liu, Gao, Yang, Wanli |
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| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Joule 3, 518 (2019) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1016/j.joule.2018.11.014 |
| Popis: | The reversibility and cyclability of anionic redox in battery electrodes hold the key to its practical employments. Here, through mapping of resonant inelastic X-ray scattering (mRIXS), we have independently quantified the evolving redox states of both cations and anions in Na2/3Mg1/3Mn2/3O2. The bulk-Mn redox emerges from initial discharge and is quantified by inverse-partial fluorescence yield (iPFY) from Mn-L mRIXS. Bulk and surface Mn activities likely lead to the voltage fade. O-K super-partial fluorescence yield (sPFY) analysis of mRIXS shows 79% lattice oxygen-redox reversibility during initial cycle, with 87% capacity sustained after 100 cycles. In Li1.17Ni0.21Co0.08Mn0.54O2, lattice-oxygen redox is 76% initial-cycle reversible but with only 44% capacity retention after 500 cycles. These results unambiguously show the high reversibility of lattice-oxygen redox in both Li-ion and Na-ion systems. The contrast between Na2/3Mg1/3Mn2/3O2 and Li1.17Ni0.21Co0.08Mn0.54O2 systems suggests the importance of distinguishing lattice-oxygen redox from other oxygen activities for clarifying its intrinsic properties. Comment: 33 pages, 8 Figures. Plus 14 pages of Supplementary Materials with 12 Figures |
| Databáze: | arXiv |
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