Method of producing non-flammable quasi-solid electrolyte and a quasi-solid electrolyte/separator layer for use in a lithium battery

Provided is a method of producing a non-flammable quasi-solid electrolyte for a lithium battery, the method comprising (A) dissolving a lithium salt in a first liquid solvent to obtain a mixture having a first concentration of lithium salt less than 3.0 M (mole/L), but greater than 0.001M; and (B) removing a portion of the first liquid solvent to obtain the quasi-solid electrolyte having a final lithium salt concentration higher than the first concentration so that the electrolyte exhibits a vapor pressure less than 0.01 kPa when measured at 20° C., a vapor pressure less than 60% of the vapor pressure of the first liquid solvent alone, a flash point at least 20 degrees Celsius higher than a flash point of the first liquid solvent alone, a flash point higher than 150° C., or no detectable flash point.