Electrolyte for electrochemical device and preparation method therefor
Disclosed are an electrolyte for an electrochemical device and preparation method thereof. The electrolyte can include a first electrode, a second electrode spaced apart from the first electrode and is filled between the first electrode and the second electrode, wherein the electrolyte further includes a salt form of a carbon quantum dot anion and a metal cation having an average diameter in the range of 2 to 12 nanometers (nm) and a surface potential of −20 mV or less, and the electrolyte has a very small dissociation energy of anion and cation, and thus improves ionic conductivity. And due to large ion polarization, and high anionic thermochemical/electrochemical stability of the electrolyte, no side reactions occur during device driving and it is possible to build an electrochemical device with greatly improved stability and reliability.
1 . A liquid phase comprising:
at least one solvent selected from the group consisting of water, methanol, ethanol, dimethyl carbonate, and ethylene carbonate; and
an electrolyte comprising a salt form consisting of:
(i) an alkali metal cation, and
(ii) a carbon quantum dot anion in a form of graphite oxide having at least one oxygen anion on a surface thereof and having an average diameter in the range of 2 to 12 nanometers (nm) and a surface potential of −20 mV or less,
wherein the electrolyte is dissolved in the at least one solvent.
2 . The liquid phase according to claim 1 , wherein the alkali metal cation is based on an alkali metal of at least one selected from the group consisting of Li, Na, K, and Cs.
3 . The liquid phase of claim 1 , wherein the salt has a structure of
wherein M is K, Na or Li.
4 . The liquid phase according to claim 1 , wherein the carbon quantum dot anion is in the form of graphite oxide having anionic forms of a carboxyl functional group or a hydroxyl functional group on the surface thereof.
5 . An electrochemical device comprising:
a first electrode;
a second electrode spaced apart from the first electrode; and
the liquid phase of claim 1 filled between the first electrode and the second electrode.
6 . The electrochemical device of claim 5 , wherein a reversible electrochemical redox reaction occurs in at least one of the first electrode and the second electrode.
7 . The electrochemical device of claim 5 , wherein the electrochemical device is a secondary battery, a solar cell, an electrochromic device or an electroluminescent device.
8 . The electrochemical device of claim 7 , wherein the secondary battery is a lithium ion battery or a lithium polymer battery.