Weakly Solvating Solution Enables Chemical Prelithiation of Graphite–SiOx Anodes for High-Energy Li-Ion Batteries
| Autor: | I. K. Kang, Jinkwan Choi, Minhyung Kwon, Hyangsoo Jeong, Minah Lee, Juyoung Jang, A-Re Jeon, Jihyun Hong |
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| Rok vydání: | 2021 |
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| Zdroj: | Journal of the American Chemical Society. 143:9169-9176 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/jacs.1c03648 |
| Popis: | Although often overlooked in anode research, the anode's initial Coulombic efficiency (ICE) is a crucial factor dictating the energy density of a practical Li-ion battery. For next-generation anodes, a blend of graphite and Si/SiOx represents the most practical way to balance capacity and cycle life, but its low ICE limits its commercial viability. Here, we develop a chemical prelithiation method to maximize the ICE of the blend anodes using a reductive Li-arene complex solution of regulated solvation power, which enables a full cell to exhibit a near-ideal energy density. To prevent structural degradation of the blend during prelithiation, we investigate a solvation rule to direct the Li+ intercalation mechanism. Combined spectroscopy and density functional theory calculations reveal that in weakly solvating solutions, where the Li+-anion interaction is enhanced, free solvated-ion formation is inhibited during Li+ desolvation, thereby mitigating solvated-ion intercalation into graphite and allowing stable prelithiation of the blend. Given the ideal ICE of the prelithiated blend anode, a full cell exhibits an energy density of 506 Wh kg-1 (98.6% of the ideal value), with a capacity retention after 250 cycles of 87.3%. This work highlights the promise of adopting chemical prelithiation for high-capacity anodes to achieve practical high-energy batteries. |
| Databáze: | OpenAIRE |
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