Battery cell manufacturing method using electrolytic solution saturated with soluble gas

A battery cell manufacturing method comprising:

• receiving an electrode assembly in a battery case;
• preparing an electrolytic solution saturated with a soluble gas;
• after receiving the electrode assembly in the battery case, purging air from the battery case using nitrogen;
• after purging air from the battery case, injecting the electrolytic solution into the battery case;
• and
• impregnating the electrode assembly with the electrolytic solution,
• wherein the impregnating the electrode assembly with the electrolytic solution comprises a process of repeatedly decompressing and pressurizing an interior of the battery case,
• wherein, in the decompressing the interior of the battery case, gas present in the battery case and the electrode assembly is discharged from the battery case together with the soluble gas,
• wherein the nitrogen is discharged from the battery case together with the soluble gas during the impregnating the electrode assembly with the electrolytic solution,
• wherein the process of repeatedly decompressing and pressurizing an interior of the battery case comprises a first decompression and pressurization and a second decompression and decompression, wherein the first and second decompression and pressurization, when in the first decompression and the second decompression are performed at different pressures from each other, and
• wherein a residual portion of the soluble gas in the battery case is used as an additive in an initial charging and discharging process of the battery cell.