Secondary battery module, a battery system including the secondary battery module and method of manufacture of the battery system

1. A secondary battery module constructed approximately in a rectangular parallelepiped structure, comprising:

right and left side members, each side member having a plurality of grooves formed at inside surfaces thereof such that sides of unit cells are securely fitted in the grooves; and

at least one connection member integrally formed with the side members such that the side members are spaced apart from each other by the width of the unit cells while the grooves of the side members face each other,

wherein the connection member is formed at the upper ends or the lower ends of the right and left side members and at the front ends or the rear ends of the right and left side members; and

a covering member for covering the opened rear ends or the opened front ends of the right and left side members while the unit cells are mounted between the right and left side members, the covering member including a plurality of protruding electrically insulating partitions,

wherein each protruding electrically insulating partition can be inserted between electrode connection parts of the unit cells, in which the electrode connection parts are regions where the electrodes of one unit cell are electrically connected to those of another unit cell.

2. The battery module as set forth in claim 1 , wherein the connection member is integrally formed at one or more of the upper ends, the lower ends, the front ends, and the rear ends of the right and left side members.

3. The battery module as set forth in claim 1 , wherein

the right and left side members are provided at the upper ends thereof with coupling protrusions, and

the right and, left side members are provided at the lower ends thereof with coupling grooves, which correspond to the coupling protrusions.

4. The battery module as set forth in claim 1 , wherein the electrode connection parts are connected in series with each other.

5. The battery module as set forth in claim 1 , wherein the unit cells are pouch-shaped lithium-ion polymer secondary cells.

6. A method of manufacturing a medium- or large-sized battery system using a secondary battery module as set forth in claim 1 , the method comprising the steps of:

(i) inserting opposite sides of one unit cell into first lowermost grooves of grooves formed at right and left side members of the battery module, such that the grooves face each other, to fix the one unit cell, and inserting opposite sides of another unit cell into second lowermost grooves of right and left side members of the battery module to fix the another unit cell, thereby stacking a plurality of unit cells in a space defined between the right and left side members;

(ii) locating an insulating auxiliary member having slits, through which electrode leads of the unit cells are inserted, on the unit cells, and electrically connecting electrode leads of the unit cells exposed above the auxiliary member either in series with each other or in series with each other after the electrode leads of the unit cells are connected in parallel with each other

(iii) electrically connecting one or more battery modules having the unit cells, electrically connected with each other, mounted therein to form a cathode terminal and an anode terminal; and

(iv) mounting a covering member at electrode connection parts.

7. The method as set forth in claim 6 , wherein step (i) includes:

applying or partially filling a bonding agent or resin into the grooves before inserting the unit cells into the grooves.

8. The method as set forth in claim 1 , wherein the electrical connection between the electrodes is accomplished by positioning conductive bus bars on the electrode leads to be connected with each other and performing laser welding.