Lithium bis(fluorosulfonyl)imide(LiFSI) is a promising replacement for lithium hexafluorosphate due to its excellent properties. A solution to the corrosion of aluminum(Al) current collectors by LiFSI at elevated temp...Lithium bis(fluorosulfonyl)imide(LiFSI) is a promising replacement for lithium hexafluorosphate due to its excellent properties. A solution to the corrosion of aluminum(Al) current collectors by LiFSI at elevated temperatures is essential. The mechanisms of Al corrosion in LiFSI-based electrolyte at 45 ℃ were studied with density functional theory calculations and spectroscopic investigations. It is found that the irregular, loose and unprotected AlF3 materials caused by the dissolution of co-generated Al(FSI)3 can exacerbate Al corrosion with the increase of temperature. Lithium bis(oxalate)borate(LiBOB) can effectively inhibit the Al corrosion with a robust and protective interphase;this can be attributed to the interfacial interactions between the Al foil and electrolyte. Boron-containing compounds promote the change from AlF3 to LiF, which further reinforces interfacial stability. This work allows the design of an interface to Al foil using LiFSI salt in lithium-ion batteries.展开更多
研究了不同浓度LiFSI对锂硫电池电化学性能的影响,结果表明在高浓度LiFSI电解液中,多硫化锂的溶解度被抑制,多硫化物的"穿梭效应"减弱,锂硫电池的循环性能提高;但是由于锂盐浓度的增加导致粘度增加以及电导率下降,锂硫电池的...研究了不同浓度LiFSI对锂硫电池电化学性能的影响,结果表明在高浓度LiFSI电解液中,多硫化锂的溶解度被抑制,多硫化物的"穿梭效应"减弱,锂硫电池的循环性能提高;但是由于锂盐浓度的增加导致粘度增加以及电导率下降,锂硫电池的循环性能劣化。锂硫电池采用2 M LiFSI电解液的性能最佳。展开更多
为探究双盐体系对高镍/硅碳电池性能的作用机制,以双氟磺酰亚胺锂(LiFSI)为主盐、六氟磷酸锂(LiPF_(6))为抑制铝箔腐蚀的辅盐,系统研究不同LiFSI/LiPF_(6)配比电解液的理化性能及对电池倍率和高温(55℃)循环稳定性的影响。通过铝箔腐蚀...为探究双盐体系对高镍/硅碳电池性能的作用机制,以双氟磺酰亚胺锂(LiFSI)为主盐、六氟磷酸锂(LiPF_(6))为抑制铝箔腐蚀的辅盐,系统研究不同LiFSI/LiPF_(6)配比电解液的理化性能及对电池倍率和高温(55℃)循环稳定性的影响。通过铝箔腐蚀表征说明LiPF_(6)的引入能有效抑制铝箔腐蚀,循环伏安法测试表明铝箔腐蚀程度和LiFSI含量呈正相关,电化学测试结果表明,优化后的混盐配比可协同提升电池倍率和高温循环性能。当LiFSI和LiPF_(6)的摩尔比为1∶1时,电池在55℃下的产气量最少、循环性能最好、循环后内阻变化率最低,高温循环0.5 C/0.5 C 370次@80%。通过精确调控LiFSI和LiPF_(6)的比例,可显著改善铝箔腐蚀与高温循环中容量衰减的问题,为高镍/硅碳电池的电解液配方优化提供关键实验依据和技术参考。展开更多
基金the financial supports from the National Natural Science Foundation of China (Nos. 21766017, 51962019)the Major Science and Technology Projects of Gansu Province, China (No. 18ZD2FA012)+1 种基金the Chinese Academy of Sciences “Western Light” Young Scholars ProjectLanzhou University of Technology Hongliu First-class Discipline Construction Program, China
文摘Lithium bis(fluorosulfonyl)imide(LiFSI) is a promising replacement for lithium hexafluorosphate due to its excellent properties. A solution to the corrosion of aluminum(Al) current collectors by LiFSI at elevated temperatures is essential. The mechanisms of Al corrosion in LiFSI-based electrolyte at 45 ℃ were studied with density functional theory calculations and spectroscopic investigations. It is found that the irregular, loose and unprotected AlF3 materials caused by the dissolution of co-generated Al(FSI)3 can exacerbate Al corrosion with the increase of temperature. Lithium bis(oxalate)borate(LiBOB) can effectively inhibit the Al corrosion with a robust and protective interphase;this can be attributed to the interfacial interactions between the Al foil and electrolyte. Boron-containing compounds promote the change from AlF3 to LiF, which further reinforces interfacial stability. This work allows the design of an interface to Al foil using LiFSI salt in lithium-ion batteries.
文摘为探究双盐体系对高镍/硅碳电池性能的作用机制,以双氟磺酰亚胺锂(LiFSI)为主盐、六氟磷酸锂(LiPF_(6))为抑制铝箔腐蚀的辅盐,系统研究不同LiFSI/LiPF_(6)配比电解液的理化性能及对电池倍率和高温(55℃)循环稳定性的影响。通过铝箔腐蚀表征说明LiPF_(6)的引入能有效抑制铝箔腐蚀,循环伏安法测试表明铝箔腐蚀程度和LiFSI含量呈正相关,电化学测试结果表明,优化后的混盐配比可协同提升电池倍率和高温循环性能。当LiFSI和LiPF_(6)的摩尔比为1∶1时,电池在55℃下的产气量最少、循环性能最好、循环后内阻变化率最低,高温循环0.5 C/0.5 C 370次@80%。通过精确调控LiFSI和LiPF_(6)的比例,可显著改善铝箔腐蚀与高温循环中容量衰减的问题,为高镍/硅碳电池的电解液配方优化提供关键实验依据和技术参考。
