High Voltage and Capacity Dual-Ion Battery Using Acetonitrile-Aqueous Hybrid Electrolyte with Concentrated LiFSI-LiTFSI
High Voltage and Capacity Dual-Ion Battery Using Acetonitrile-Aqueous Hybrid Electrolyte with Concentrated LiFSI-LiTFSI
复制标题
使用乙腈-水混合电解质和浓缩 LiFSI-LiTFSI 的高电压和高容量双离子电池
DOI：
10.1149/1945-7111/acaad1
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发表时间：
2022
影响因子：
3.9
通讯作者：
Ishihara Tatsumi
中科院分区：
文献类型：
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作者：
Yang Dengyao;Watanabe Motonori;Takagaki Atsushi;Ishihara Tatsumi
研究了高电位大容量可充电双离子电池中含有高浓度双（三氟甲磺酰）亚胺（LiTFSI）和双（氟磺酰）亚胺锂（LiFSI）（LiTFSI-LiFSI= 3:1，摩尔比）负载盐的水-乙腈（AN）杂化电解质。水-乙腈杂化电解质（WA）具有较宽的电化学稳定窗口，在20 m水溶液中为3.1 V，在20 m 9LiFSI-1LiTFSI: AN= 1:3摩尔比电解质中为3.6 V。特别是高氧化电位，这可以归因于AN，水和LiTFSI-LiFSI支持盐之间形成的强溶剂化离子团簇。该双离子电池分别以石墨碳（KS6）和活性炭（AC）为阴极和阳极，以混合AN-water中的20 m LiTFSI-LiFSI为电解质组装而成。结果表明，该方法具有较大的容量、库仑效率和循环稳定性。在0-3.25 V电压范围内，KS6/AC电池在初始循环时为86 mAh g−1，在第100次循环时为50 mAh g−1，在200次循环中平均库仑效率保持在85%。ATR-IR和NMR分析表明，AN的加入增强了水对Li+的溶剂化结构，这种溶剂化结构的改变是水双离子电池性能提高的主要原因。
Water-acetonitrile (AN) hybrid electrolyte with high concentration of bis (trifluoromethanesulfonyl) imide (LiTFSI) and Lithium bis (fluorosulfonyl) imide (LiFSI)(LiTFSI-LiFSI= 3: 1, molar ratio) supporting salts are studied for the high potential and large capacity rechargeable dual-ion battery. Water-acetonitrile hybrid electrolyte (WA) shows a wide electrochemical stability window of 3.1 V in 20 m aqueous electrolyte and 3.6 V in 20 m 9LiFSI-1LiTFSI in water: AN= 1: 3 molar ratio electrolyte. In particular, high oxidation potential, which can be assigned to the strong solvated ionic cluster formed between AN, water and LiTFSI-LiFSI supporting salts. The dual-ion battery is assembled using the graphitic carbon (KS6) and the activated carbon (AC) as cathode and anode, respectively, and 20 m LiTFSI-LiFSI in hybrid AN-water as electrolyte. It is found that the reasonably large capacity, coulombic efficiency and cycle stability were achieved. The KS6/AC cell shows 86 mAh g− 1 at the initial cycle and 50 mAh g− 1 at 100th cycle in a voltage range of 0–3.25 V, and the average coulombic efficiency of 85% is sustained over 200 cycles. The solvated structure of water to Li+ is strengthened by addition of AN from ATR-IR and NMR spectrums analysis and this change in the solvated structure is the main reason for the increased performance of the aqueous dual-ion battery.