2024-01-24 パシフィック・ノースウェスト国立研究所(PNNL)
◆このシンプルで調整可能な手法は、高コストや特殊な材料を必要とせず、異なるイオンの挙動に基づいています。今後は大規模な拡張と効率的な回収方法の研究が進む見通しです。
＜関連情報＞
- https://www.pnnl.gov/publications/separating-critical-materials-dissolved-batteries
- https://pubs.acs.org/doi/full/10.1021/acs.estlett.3c00754
電池原料溶液からの金属イオンの逐次析出を促進する反応拡散カップリング Reaction–Diffusion Coupling Facilitates the Sequential Precipitation of Metal Ions from Battery Feedstock Solutions
Qingpu Wang,and Elias Nakouzi
Environmental Science & Technology Letters Published:November 22, 2023
DOI:https://doi.org/10.1021/acs.estlett.3c00754
Abstract
The development of new technologies for chemical separations is urgently needed to meet the surging demand for critical materials that has strained resources and caused environmental challenges. Inspired by the classic Liesegang experiment, we demonstrated the separation of critical metal ions based on the coupling of ion diffusion and precipitation kinetics. For this purpose, a model feedstock solution simulating dissolved battery electrodes was placed on top of a hydrogel loaded with a precipitating agent, namely, sodium hydroxide. As the lithium, manganese, cobalt, and nickel ions diffused into the gel, a gradient of precipitates formed along the length of the reactor. Elemental analysis of the spatially distributed precipitates showed the enrichment of nickel near the gel–solution interface, followed by the formation of an almost pure (>96%) manganese product further along the reactor. Optimization experiments revealed that a sodium hydroxide concentration of 10 mM and a gel/solution volume ratio of 2:1 favored efficient separations. The robustness of the method was demonstrated in four out of five feedstock compositions of typically used battery cathodes. Our proof-of-concept experiments present a paradigm for critical materials separations that does not require specialty chemicals, binding agents, membranes, or toxic solvents.
