Lithium-sulfur(Li-S)batteries have attracted enormous interest due to their super-high theoretical energy density(2600 W·h/kg)in recent years.However,issues such as lithium dendrites and the shuttle effect severe...Lithium-sulfur(Li-S)batteries have attracted enormous interest due to their super-high theoretical energy density(2600 W·h/kg)in recent years.However,issues such as lithium dendrites and the shuttle effect severely hampered the large-scale application of Li-S batteries.Herein,a novel bifunctional gel polymer electrolyte,poly(N,Ndiallyl-N,N-dimethylammonium bis(trifluoromethylsulfonylimide))-P(VDF-HFP)(PDDA-TFSI-P(VDF-HFP),PTP),was prepared by anion exchange reaction to tackle the above problems.Benefited from the interaction between TFSI-and quaternary ammonium ion in PTP,a higher lithium-ion transference number was obtained,which could availably protect Li metal anodes.Meanwhile,due to the adsorption interactions between PDDA-TFSI and polysulfides(LiPSs),the shuttle effect of Li-S batteries could be alleviated effectively.Consequently,the Li symmetric batteries assembled with PTP cycled more than 1000 h and lithium metal anodes were protected effectively.Li-S batteries assembled with this polymer electrolyte show a discharge specific capacity of 813 mA·h/g after 200 cycles and 467 mA·h/g at 3 C,exhibiting excellent cycling stability and C-rates performance.展开更多
A CO<sub>2</sub> capture system without supercritical CO<sub>2</sub> was optimized for mixtures of hydrophobic room temperature ionic liquids (RTILs) and propanol. We tested RTILs using bis(tri...A CO<sub>2</sub> capture system without supercritical CO<sub>2</sub> was optimized for mixtures of hydrophobic room temperature ionic liquids (RTILs) and propanol. We tested RTILs using bis(trifluoromethanesulfonyl)imide, TFSI-, anion and four quaternary ammonium cations, two quaternary phosphonium cations, and one imidazolium cation. The addition of 2-propanol into the RTILs clearly promoted the capture of normal CO<sub>2</sub>(nCO<sub>2</sub>) at ambient temperature and pressure. When combined with 2-propanol, the most efficient RTILs for nCO<sub>2</sub> capture were N-butyl-N,N,N-trimethylammonium TFSI-. This enhancement of nCO<sub>2</sub> capture was not observed in RTIL mixtures with 1-propanol or in propanol mixtures containing other phosphonium- and imidazolium-based RTILs. The torsion angle of TFSI-, which was calculated using density functional theory, is thought to be related to high nCO<sub>2</sub> capture efficiently.展开更多
The electrochemical reversibility of Mg in hybrid electrolytes based on mixtures of ionic liquid and glyme based organic solvents was investigated for applications in rechargeable magnesium batteries(RMBs). The electr...The electrochemical reversibility of Mg in hybrid electrolytes based on mixtures of ionic liquid and glyme based organic solvents was investigated for applications in rechargeable magnesium batteries(RMBs). The electrolytes demonstrate reversible reduction and oxidation of Mg only after being pre-treated with the dehydrating agent, magnesium borohydride, Mg[BH_4]_2, highlighting the importance of removing water in Mg based electrolytes. The addition magnesium di[bis(trifluoromethanesulfonyl)imide](Mg[TFSI]_2)(0.3 M) to N-butyl-n-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide [C4 mpyr][TFSI]/tetraglyme at a mole ratio of 1:2 showed stable CV cycling over almost 300 cycles while scanning electron microscopy(SEM) and X-ray diffraction(XRD) confirmed Mg deposition, showing non-dendritic morphology and a well-aligned growth. Further thermogravimetric analysis(TGA) demonstrated a mass retention of 79% at 250℃ for this electrolyte suggesting that the presence of the ionic liquid increases thermal stability substantially making these hybrid electrolytes compatible for RMBs.展开更多
The polypropylene/glass fiber（PP/GF） composites with excellent antistatic performance and improved mechanical properties have been reported by incorporation of a very small amount of the organic salt, lithium bis（t...The polypropylene/glass fiber（PP/GF） composites with excellent antistatic performance and improved mechanical properties have been reported by incorporation of a very small amount of the organic salt, lithium bis（trifluoromethanesulfonyl）imide（Li-TFSI）, into the PP/GF composites. It was considered that GF could play the role as the pathways for the movements of ions in the ternary composites. In this work, the interactions between Li-TFSI and glass fiber and the effects of such interactions on the physical properties of the composites have been systematically investigated. Three types of glass fibers with different ―OH group concentrations have been prepared in order to compare the interactions between GF and Li-TFSI. It was found that the ―OH group concentrations on the surface of glass fiber have significant effects on interactions between glass fibers and Li-TFSI. Such interactions are crucial for both the antistatic and mechanical performances of the final PP/GF/Li-TFSI composites. The investigation indicated that the GF with high ―OH group concentrations confined the movement of TFSI-, which decreased the antistatic properties of PP/GF/Li-TFSI composites. On the other hand, the GF with low ―OH group concentrations inhibited the absorption of Li-TFSI onto the GF, which also hindered the formation of Li-TFSI conductive pathway. The best antistatic performance of the ternary composites can be achieved at the intermediate ―OH concentrations on the GF.展开更多
基金Project(21935006)supported by the National Natural Science Foundation of China。
文摘Lithium-sulfur(Li-S)batteries have attracted enormous interest due to their super-high theoretical energy density(2600 W·h/kg)in recent years.However,issues such as lithium dendrites and the shuttle effect severely hampered the large-scale application of Li-S batteries.Herein,a novel bifunctional gel polymer electrolyte,poly(N,Ndiallyl-N,N-dimethylammonium bis(trifluoromethylsulfonylimide))-P(VDF-HFP)(PDDA-TFSI-P(VDF-HFP),PTP),was prepared by anion exchange reaction to tackle the above problems.Benefited from the interaction between TFSI-and quaternary ammonium ion in PTP,a higher lithium-ion transference number was obtained,which could availably protect Li metal anodes.Meanwhile,due to the adsorption interactions between PDDA-TFSI and polysulfides(LiPSs),the shuttle effect of Li-S batteries could be alleviated effectively.Consequently,the Li symmetric batteries assembled with PTP cycled more than 1000 h and lithium metal anodes were protected effectively.Li-S batteries assembled with this polymer electrolyte show a discharge specific capacity of 813 mA·h/g after 200 cycles and 467 mA·h/g at 3 C,exhibiting excellent cycling stability and C-rates performance.
文摘A CO<sub>2</sub> capture system without supercritical CO<sub>2</sub> was optimized for mixtures of hydrophobic room temperature ionic liquids (RTILs) and propanol. We tested RTILs using bis(trifluoromethanesulfonyl)imide, TFSI-, anion and four quaternary ammonium cations, two quaternary phosphonium cations, and one imidazolium cation. The addition of 2-propanol into the RTILs clearly promoted the capture of normal CO<sub>2</sub>(nCO<sub>2</sub>) at ambient temperature and pressure. When combined with 2-propanol, the most efficient RTILs for nCO<sub>2</sub> capture were N-butyl-N,N,N-trimethylammonium TFSI-. This enhancement of nCO<sub>2</sub> capture was not observed in RTIL mixtures with 1-propanol or in propanol mixtures containing other phosphonium- and imidazolium-based RTILs. The torsion angle of TFSI-, which was calculated using density functional theory, is thought to be related to high nCO<sub>2</sub> capture efficiently.
基金support from the Australian Research Council for his Australian Laureate Fellowship
文摘The electrochemical reversibility of Mg in hybrid electrolytes based on mixtures of ionic liquid and glyme based organic solvents was investigated for applications in rechargeable magnesium batteries(RMBs). The electrolytes demonstrate reversible reduction and oxidation of Mg only after being pre-treated with the dehydrating agent, magnesium borohydride, Mg[BH_4]_2, highlighting the importance of removing water in Mg based electrolytes. The addition magnesium di[bis(trifluoromethanesulfonyl)imide](Mg[TFSI]_2)(0.3 M) to N-butyl-n-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide [C4 mpyr][TFSI]/tetraglyme at a mole ratio of 1:2 showed stable CV cycling over almost 300 cycles while scanning electron microscopy(SEM) and X-ray diffraction(XRD) confirmed Mg deposition, showing non-dendritic morphology and a well-aligned growth. Further thermogravimetric analysis(TGA) demonstrated a mass retention of 79% at 250℃ for this electrolyte suggesting that the presence of the ionic liquid increases thermal stability substantially making these hybrid electrolytes compatible for RMBs.
基金financially supported by the National Natural Science Foundation of China(Nos.21674033 and 51173036)
文摘The polypropylene/glass fiber（PP/GF） composites with excellent antistatic performance and improved mechanical properties have been reported by incorporation of a very small amount of the organic salt, lithium bis（trifluoromethanesulfonyl）imide（Li-TFSI）, into the PP/GF composites. It was considered that GF could play the role as the pathways for the movements of ions in the ternary composites. In this work, the interactions between Li-TFSI and glass fiber and the effects of such interactions on the physical properties of the composites have been systematically investigated. Three types of glass fibers with different ―OH group concentrations have been prepared in order to compare the interactions between GF and Li-TFSI. It was found that the ―OH group concentrations on the surface of glass fiber have significant effects on interactions between glass fibers and Li-TFSI. Such interactions are crucial for both the antistatic and mechanical performances of the final PP/GF/Li-TFSI composites. The investigation indicated that the GF with high ―OH group concentrations confined the movement of TFSI-, which decreased the antistatic properties of PP/GF/Li-TFSI composites. On the other hand, the GF with low ―OH group concentrations inhibited the absorption of Li-TFSI onto the GF, which also hindered the formation of Li-TFSI conductive pathway. The best antistatic performance of the ternary composites can be achieved at the intermediate ―OH concentrations on the GF.
