Beschreibung:
<jats:p> As a means of addressing global warming, the world is increasingly turning to the use of Li-ion batteries in electric vehicles and as storage batteries in the home; therefore, there is a growing need for Li. Furthermore, as a fuel for fusion reactors, tritium is produced by the reaction of lithium with neutrons in a tritium-breeding material. </jats:p>
<jats:p>Li is primarily recovered from salt lakes in South America but is also present in seawater. Thus, I propose a method for recovering Li from seawater by using innovative dialysis, wherein Li only permeates from the negative electrode side to the positive electrode side through a Li ionic superconductor functioning as a Li separation membrane (LISM) (Fig.1). Measurements of the Li ion concentration at the positive electrode side as a function of dialysis duration showed that the Li recovery ratio increased to approximately 7% after 72 h with no applied electric voltage, and an electrical power of 0.04 V and 0.1 mA was generated. Moreover, other ions in the seawater did not permeate the LISM. With both ends of the LISM bound with a negative and positive electrode, hydrated Li ion was transformed to Li ion only because Li ion can permeate through the LISM [1]. </jats:p>
<jats:p>Furthermore, tritium needed as a fuel for fusion reactors is produced via neutron capture by lithium-6 (<jats:sup>6</jats:sup>Li). However, natural Li contains only about 7.8% <jats:sup>6</jats:sup>Li, and enrichment of <jats:sup>6</jats:sup>Li up to 90% is required for adequate tritium breeding in fusion reactors. </jats:p>
<jats:p>Therefore, new Li isotope separation technique using a Li ionic rconductor functioning as a LISM have been developed. Because the mobility of <jats:sup>6</jats:sup>Li ions is higher than that of <jats:sup>7</jats:sup>Li ions, <jats:sup>6</jats:sup>Li can be enriched on the cathode side of a cell. Using Li<jats:sub>0.29</jats:sub>La<jats:sub>0.57</jats:sub>TiO<jats:sub>3</jats:sub> (LLTO) as the Li ionic superconductor was prepared, and the relationship between the <jats:sup>6</jats:sup>Li separation coefficient and the electrodialysis time was investigated. After electrodialysis, we obtained a maximum of 1.05 for the <jats:sup>6</jats:sup>Li isotope separation coefficient. This result showed that the <jats:sup>6</jats:sup>Li isotope separation coefficient of this method is the same as that of the amalgamation process using mercury (1.06). Thus, this method has the potential to be a superior <jats:sup>6</jats:sup>Li enrichment method to produce 90% enriched tritium breeder for fusion reactors. </jats:p>
<jats:p>[1] T. Hoshino, Desalination, 359, 59-63 (2015).</jats:p>
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<jats:p>Figure 1</jats:p>
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