Non-aqueous electrolyte for secondary battery, secondary battery having the same and method of manufacturing the same

A non-aqueous electrolyte for a secondary battery, comprising:

• an electrolytic salt, a first solvent, and a second solvent,
• wherein:
• the electrolytic salt is included at a concentration of about 1.7 M (mol/L) to about 3.0 M (mol/L) in the non-aqueous electrolyte,
• the first solvent has a solubility of the electrolytic salt in a range from about 100 g to about 400 g,
• the second solvent has a solubility of the electrolytic salt of less than or equal to about 1 g;
• the first solvent comprises a coordination solvent coordinated with an ionized ion from the electrolytic salt and a free solvent not coordinated with an ionized ion from the electrolytic salt;
• wherein the second solvent is trifluorotoluene (CF3Ph);
• an amount of the first solvent, an amount of the second solvent, and the concentration of the electrolytic salt together provide a viscosity of the non-aqueous electrolyte of 3.8 mPa·s to 22 mPa·s;
• and
• a peak area ratio of the free solvent determined by a Raman spectrum is less than about 20%.