Recently run in lithium heat
Ion batteries strengthen the study of safer electrolyte based on ionic liquids.
It turns out that simple conversion from organic solvents to ionic liquids is difficult, because the reduced conductivity and increased viscosity of ionic liquids lead to a decrease in battery efficiency after the addition of lithium salts.
The new trend of replacing lithium salt with cheaper alternatives-sodium salt leads to a fairly poor solubility of sodium salt in commonly used ionic liquids.
This phenomenon is largely unexplained.
Here we propose a high
Horizontal quantum chemistry study on the chemical binding of lithium and sodium salt to ionic liquid anion.
Since they are close to the anion, it is found that the 1s2 electrons on the lithium cation become strongly polarized due to the presence of the anion, making them begin to participate in bonding, making it more affinity than originally thought.
In the sodium salt, the 2s2 orbital is removed from the anion, making its effect weak.
This polarization results in 90 kilojoules mol-
The difference in the interaction between lithium and sodium salt.
The theoretical calculation results confirm that the Advanced Unit of lithium salt and the solubility of the advanced individual Valence are increased because of these dissolved chemical vapor deposition
Matching match
The disadvantage of this ability is that the conductivity is reduced because lithium salts are not very easy to disintegrate in ionic liquids.
Sodium salts have been shown to maintain a high degree of ionic properties, thus reducing their chances of being dissolved by ionic liquids because of their low ion concentration per unit volume.
The theoretical results are further supported by the study of the solubility of MX salt, where M = Li or Na and X = bis (trifluoride toluene ester) Dione (NTf2), BF4-or PF6 -
, In six different ionic liquids.
BF4-lithium salt composedor PF6 -
At least one order of magnitude shows better solubility than their sodium analogs.
The findings of this work will have an impact on the future development direction of lithium and sodium-safe electrolyte
Ion secondary battery.