Secondary battery static pressure jig and secondary cell internal pressure control method using the same

A secondary battery static pressure jig, comprising:

• a supporting member disposed to support opposite surfaces of a battery cell to apply pressure to the battery cell;
• a piezoelectric element disposed between a surface of the supporting member and one of the opposite surfaces of the battery cell contacting each other to measure a pressure applied to the battery cell;
• and
• a controller configured to control a volume of the piezoelectric element according to the pressure measured by the piezoelectric element,
• wherein the volume of the piezoelectric element is changed according to a volume change of the battery cell,
• wherein the pressure applied to the battery cell is made to be a constant pressure by a volume change of the piezoelectric element,
• wherein one of opposite surfaces of the piezoelectric element contacts the supporting member and the other of opposite surfaces of the piezoelectric element contacts the battery cell, and
• wherein the piezoelectric element controls the pressure applied to the battery cell by the volume change of the piezoelectric element when a pressure between the battery cell and the supporting member is changed according to the volume change of the battery cell.