We report on the reversible (de)intercalation of TFSI⁻ anions from a Mg‐based ionic liquid electrolyte, Mg(TFSI)₂ in Pyr₁₄TFSI, in graphite activated carbon hybrid dual‐ion capacitor (DIC) cells. The role of different pseudo reference electrodes (PREs) including Ag‐wire and Li metal is discussed regarding the comparability of different battery cells. We show that an Ag‐wire PRE is not suitable for the designated purpose, while the use of a Li metal PRE results in high reproducibility. Mg‐based DIC cells are compared with cells based on pure Pyr₁₄TFSI and LiTFSI‐Pyr₁₄TFSI electrolytes, and with graphite Li metal dual‐ion cells employing LiTFSI‐Pyr₁₄TFSI. At 5.2 V vs. Li|Li⁺, Mg‐containing DIC cells reveal an improved performance compared to Li‐based cells, i. e., higher capacity (87 vs. 85 mAh g⁻¹) and higher Coulombic efficiency (98 vs. 96 %). These results may pave the way to further studies and performance improvements of Mg‐based batteries and to hybrid DIC chemistries with other cations, especially multi‐valent ones.

中文翻译：

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为混合双离子电容器启用基于镁的离子液体电解质

我们对TFSI的可逆（DE）嵌入报告^-从基于Mg的离子液体电解质的阴离子，镁（TFSI）₂在比利₁₄ TFSI，在石墨活性碳混合双重离子电容器（DIC）的细胞。关于不同电池单元的可比性，讨论了包括银线和锂金属在内的不同伪参比电极（PRE）的作用。我们表明，Ag-wire PRE不适合用于指定目的，而使用Li金属PRE则可实现高重现性。将基于Mg的DIC电池与基于纯Pyr ₁₄ TFSI和LiTFSI-Pyr ₁₄ TFSI电解质的电池以及采用LiTFSI-Pyr _14的石墨Li金属双离子电池进行比较TFSI。在5.2V，VS。Li | Li ⁺，含Mg的DIC电池与基于Li的电池相比，表现出更高的性能。例如，更高的容量（87 vs. 85 mAh g ^-1）和更高的库仑效率（98 vs. 96％）。这些结果可能为进一步研究和改进基于Mg的电池以及将DIC化学与其他阳离子（尤其是多价阳离子）混合铺平道路。