Generally, research into a secondary battery capable of being charged and discharged unlike a primary battery has been actively conducted in accordance with the development of state-of-the-art fields such as a digital camera, a cellular phone, a notebook, a hybrid automobile, and the like. An example of the secondary battery includes a nickel-cadmium battery, a nickel-metal hydride battery, a nickel-hydrogen battery, and a lithium secondary battery. Among them, the lithium secondary battery having an operating voltage of 3.6V or more is used as a power supply of a portable electronic device or a plurality of lithium secondary batteries are connected in series with each other to thereby be used for a high output hybrid automobile. Since this lithium secondary battery has the operating voltage three times higher than that of the nickel-cadmium battery or the nickel-metal hydride battery and is more excellent in view of energy density characteristics per unit weight than the nickel-cadmium battery or the nickel-metal hydride battery, the use of the lithium secondary battery has rapidly increased.
The lithium secondary battery may be manufactured in various types. As a representative type of the lithium secondary battery, there are a cylindrical type and a prismatic type that are mainly used for a lithium ion battery. A lithium polymer battery that has been recently spotlighted is manufactured in a pouch type having flexibility, such that it has a relatively free shape.
The pouch type lithium polymer battery (hereinafter, referred to as “pouch type cell”) needs to be protected by a firm case apparatus in order to be used for a long time since it may be easily bent or curved. However, according to the related art, a method in which electrode taps of the respective pouches are connected to each other by a printed circuit board on which circuit patterns are formed for the series connection and are put into a case has been used.
However, a method for configuring a high output battery module by stacking the pouch type cells according to the related art may not safely protect the pouch type cells having a weak structure and also uses an imperfect scheme in which a plurality of pouch type cells are stacked to be connected to the PCB, such that it is not strong against an environment change such as external impact, or the like.
As a method capable of more firmly and stably stacking the pouch type cells configuring the lithium battery used for a high output power source and reliably connecting them in series with each other, there is Korean Patent Laid-Open Publication No. 2006-0102207 entitled “Case for High Power Rechargeable Lithium Battery”.
Referring to FIG. 1, “Case for High Power Rechargeable Lithium Battery” of Korean Patent Laid-Open Publication No. 2006-0102207 includes a pouch supporting frame 21 supporting a pouch 11 of a pouch type cell 10 including the pouch 11 and an electrode tap 12, a shelf type heat dissipating part 22 formed on one surface of the pouch supporting frame 21 and providing a space to which heat generated in the pouch 11 is discharged, and a wall type tap supporting part 23 formed at one side of the heat dissipating part 22 to support the electrode tap 12 of the pouch type cell 10.
Referring to FIG. 2, a battery module 30 in which the pouch type cells 10 are firmly and stably stacked using “Case for High Power Rechargeable Lithium Battery” as described above may be manufactured.
However, since the battery module 30 as described above needs to couple the pouch supporting frame 21 onto both sides of the pouch cell 10 and electrically connect the pouch cell 10 and a neighboring pouch cell to each other, a process for manufacturing the same may be complex and assembly property and production property may not be excellent.