How can ⁶Li sequestration for tritium breeding be tracked in situ?

Luis Carrillo, Sarbajit Banerjee, and their colleagues at Texas A&M University, together with collaborators from Canadian Light Source have used the Hummingbird Scientific Gen V X-ray liquid electrochemistry sample holder to investigate the mechanism behind a hybrid capacitive deionization approach for ⁶Li enrichment for tritium breeding in nuclear fusion reactor materials. Selective insertion of lithium ions into the 1D tunnels of ζ‑V₂O₅ was achieved based on isotope dependent mobility within the tunnels and measured by in-situ scanning transmission electron microscopy (STXM) and hard X-ray photoemission spectroscopy (XPS).

a) Schematic of hybrid capacitive deionization (HCDI) cell using 1D tunnels of ζ ‑V₂O₅ for the separation of ⁶Li and ⁷Li ions. b-e) X-ray optical density images showing the unlithiated state, first reduction (1 nA for 600 s), first oxidation (1 nA for 600 s), and second reduction (2 nA for 600 s). Scale bars = 1 μm. f-i) Corresponding lithiation content maps based on the color scale at right; scale bars = 1 μm. j) Open-circuit voltage profile over 600 s. k-m) Chronopotentiometry curves for reduction cycle 1, oxidation cycle 1, and reduction cycle 2, respectively. Copyright © 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

In-situ STXM imaging confirmed uniform, reversible lithiation across ζ‑V₂O₅ particles, demonstrating the faradaic processes that enable repeatable sequestration and release. Lithium ions were inserted into the 1D tunnels rather than just adsorbed on surface, improving selectivity, stability, and controlled release, the key to isotope separation. Currently, the supply of ⁶Li for nuclear fusion is limited by the inefficiency, environmental impact, and complexity of the mercury-based COLEX enrichment process. This study achieved an enrichment factor of ca. 57‰, competitive with the standard COLEX method. The demonstrated method offers a cleaner, more efficient route to ⁶Li enrichment for fusion energy applications.

Reference: J. Luis Carrillo,  Andrew A. Ezazi, Saul Perez-Beltran, Carlos A. Larriuz, Harris Kohl, Jaime A. Ayala, Arnab Maji, Stanislav Verkhoturov, Mohammed Al-Hashimi, Hassan Bazzi, Conan Weiland, Cherno Jaye, Daniel A. Fischer, Lucia Zuin, Jian Wang, Sarbajit Banerjee, Chem 11(8), 102486 (2025) DOI: 10.1016/j.chempr.2025.102486

Full paper Copyright © 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

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