Battery module having initial pressing force strengthening structure for cell assembly, and method for manufacturing same

A method of manufacturing a battery module, comprising:

• preparing a first module housing, which includes a lower plate having a rectangular plate form and a first left pressing plate and a first right pressing plate having elasticity and extending upwards at both side edge regions of the lower plate, which are provided side by side, to form an acute angle with respect to a vertical direction so that a gap between the first left pressing plate and the first right pressing plate becomes narrowed upwards, and a cell stack that is to be accommodated in the first module housing;
• pulling the first left pressing plate and the first right pressing plate apart within an elastic limit to broaden the gap therebetween, then inserting the cell stack into the first module housing, and releasing the first left pressing plate and first right pressing plate to press both side surfaces of the cell stack;
• preparing a second module housing, which includes an upper plate having a rectangular plate form and a second left pressing plate and a second right pressing plate having elasticity and extending downwards respectively at both side edge regions of the upper plate, which are provided side by side, to form an acute angle with respect to a vertically lower direction so that a gap between the second left pressing plate and the second right pressing plate becomes narrowed downwards;
• and
• pulling the second left pressing plate and second right pressing plate apart within an elastic limit to place the upper plate on upper ends of the first left pressing plate and the first right pressing plate, and then releasing the second left pressing plate and the second right pressing plate to press the first left pressing plate and the first right pressing plate.