Lithium carbonate (Li₂CO₃) is observed in conventional lithium-ion batteries in which cell performance has been reduced. In this paper, a catalyst to electrochemically decompose Li₂CO₃ was investigated to develop a Li reproduction technology. It has been accepted that iodine with a redox potential below 3.5 V vs Li⁺/Li cannot decompose Li₂CO₃, because the decomposition potential of Li₂CO₃ is 3.82 V vs Li⁺/Li. Here, we observed that the redox potential of iodine in trimethyl phosphate (TMP) and dimethyl sulfoxide (DMSO) solutions increased up to 4.0 V, and thus Li₂CO₃ could be chemically decomposed by iodine in these solvents. This unexpectedly high redox potential may be caused by deviation of the electric charges on two iodine atoms due to a 1:1 complex formation of iodine with the solvent. Reaction pathways are discussed with respect to the chemical decomposition of Li₂CO₃ by iodine. We combined the chemical decomposition behavior with the redox couple of iodine species. A double-chamber type cell with carbon paper as cathode in catholyte that dissolved iodine and suspended Li₂CO₃ powders was constructed to substantiate a catalytic cycle for Li₂CO₃ decomposition. The cell was demonstrated to be rechargeable due to the decomposition of Li₂CO₃.

中文翻译：

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异常高氧化还原电势的碘介体及其在碳酸锂分解催化循环中的应用

在传统的锂离子电池中观察到碳酸锂（Li ₂ CO ₃），其中电池性能已经降低。本文研究了一种电化学分解Li ₂ CO ₃的催化剂，以开发Li再生技术。它已被接受的是，碘具有低于3.5V的相对于Li的氧化还原电位⁺ /锂不能分解李₂ CO ₃，因为Li的分解电势₂ CO ₃是3.82 V相对于锂⁺ /锂。在这里，我们观察到碘在磷酸三甲酯（TMP）和二甲基亚砜（DMSO）溶液中的氧化还原电势增加到4.0 V，因此Li ₂在这些溶剂中，CO ₃可以被碘化学分解。出乎意料的高氧化还原电势可能是由于碘与溶剂的1：1络合物形成，导致两个碘原子上的电荷偏离而引起的。讨论了关于碘对Li ₂ CO ₃的化学分解的反应途径。我们将化学分解行为与碘物种的氧化还原对结合起来。构建了一种以碳纸为阴极的双室型电解池，该电解池溶解了碘并悬浮了Li ₂ CO ₃粉末，从而证实了Li ₂ CO ₃的催化循环。分解。由于Li ₂ CO ₃的分解，该电池被证明是可充电的。