Origin of enhanced capacity retention of aqueous potassium-ion batteries using monohydrate-melt electrolyte
Origin of enhanced capacity retention of aqueous potassium-ion batteries using monohydrate-melt electrolyte
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DOI：
10.1016/j.jpowsour.2022.232096
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发表时间：
2022-11
影响因子：
9.2
通讯作者：
Tomooki Hosaka;R. Takahashi;K. Kubota;R. Tatara;Yuki Matsuda;Kazuhiko Ida;Kanji Kuba;S. Komaba
中科院分区：
文献类型：
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作者：
Tomooki Hosaka;R. Takahashi;K. Kubota;R. Tatara;Yuki Matsuda;Kazuhiko Ida;Kanji Kuba;S. Komaba
将二（氟磺酰基）酰胺钾盐（FSA−）和三氟甲磺酸钾（OTf−）以6：4的摩尔比混合，制备了一水合钾盐熔体作为水溶液K离子电池的电解质，并与KFSA·1.8H2O和KOTf·2.8H2O的电解质进行了物理化学性质和电极反应的比较。由于K（FSA）0.6（OTf）0.4 × 1.0H2O具有比端元更宽的2.56 V的电势窗口，因此一水合物熔融电解质实现了3，4，9，10-二萘嵌苯四甲酸二酰亚胺（PTCDI）的含水K离子电池的高度可逆的充放电循环。||K2Fe0.5Mn0.5[Fe（CN）6]。的K2Fe0.5Mn0.5[Fe（CN）6]电极表现出较少的退化的电极和晶体结构中的一水合物熔体比在端元。此外，PTCDI在一水合物熔融电解质中的可逆充放电反应归因于PTCDI的较低溶解度和由FSA−分解产物如KF组成的固体电解质中间相的形成。
A potassium salt monohydrate melt was prepared as an electrolyte for aqueous K-ion batteries by mixing potassium salts of bis(fluorosulfonyl)amide (FSA−) and triflate (OTf−) in a 6:4 molar ratio, and the physicochemical properties and electrode reactions in the hydrate melt electrolyte were compared with those of KFSA·1.8H2O and KOTf·2.8H2O. Since the K(FSA)0.6(OTf)0.4･1.0H2O has a wider potential window of 2.56 V than the endmembers, the monohydrate melt electrolyte realizes highly reversible charge–discharge cycles of an aqueous K-ion battery of 3,4,9,10-perylenetetracarboxylic diimide (PTCDI) ||K2Fe0.5Mn0.5[Fe(CN)6]. The K2Fe0.5Mn0.5[Fe(CN)6] electrode exhibited less degradation of the electrode and crystal structures in the monohydrate melt than in the endmembers. Further, the reversible charge–discharge reaction of PTCDI in the monohydrate melt electrolyte is attributed to the lower solubility of PTCDI and the formation of solid electrolyte interphase consisting of FSA−decomposed products such as KF.