Battery module having movable pressurization member

Disclosed herein is a battery module including a module case, a battery cell stack mounted in the module case, and a movable pressurization member for pressurizing the battery cell stack.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2014/006355, filed Jul. 15, 2014, which claims priority to Korean Patent Application No. 10-2013-0087899 filed on Jul. 25, 2013, the disclosures of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a battery module including a movable pressurization member.

BACKGROUND ART

As mobile devices have been increasingly developed, and the demand for such mobile devices has increased, the demand for secondary batteries has also sharply increased as an energy source for the mobile devices. Among such secondary batteries is a lithium secondary battery having a high energy density and discharge voltage, into which much research has been carried out and which is now commercialized and widely used.

In general, a secondary battery is configured to have a structure in which an electrode assembly including a positive electrode and a negative electrode stacked or wound in a state in which a separator is disposed between the positive electrode and the negative electrode is mounted in a battery case made of a metal can or a laminate sheet, and an electrolyte is injected into the battery case or the electrode assembly is impregnated with the electrolyte.

However, the secondary battery may have problems in that if the pressure of the battery is not uniformly maintained during the use of the battery, a large amount of gas generated in the battery increases the thickness of the battery, and the electrolyte may leak through sealed portion of the battery case.

Therefore, there is a high necessity for a novel lithium secondary battery that is capable of solving the above problems.

DISCLOSURE

Technical Problem

The present invention has been made to solve the above problems and other technical problems that have yet to be resolved.

It is an object of the present invention to provide a battery module that is capable of uniformly maintaining the pressure of battery cells and preventing leakage of an electrolyte.

Technical Solution

In accordance with one aspect of the present invention, the above and other objects can be accomplished by the provision of a battery module including a module case, a battery cell stack mounted in the module case, and a movable pressurization member for pressurizing the battery cell stack.

The battery module according to the present invention includes the movable pressurization member for pressurizing the battery cell stack. Consequently, it is possible to uniformly maintain the pressure of battery cells constituting the battery cell stack and to prevent leakage of an electrolyte.

The movable pressurization member may be disposed between the module case and the battery cell stack.

The movable pressurization member may include a support member including a separable base plate and leg members coupled to opposite ends of the separable base plate, sliding movement members for moving the support member in directions opposite to directions in which the battery cell stack are pressurized, and a stopper member for stopping movement of the sliding movement members by stages. The separable base plate may be configured to have a structure in which when the distance between the leg members coupled to opposite ends of the separable base plate is increased due to swelling of the battery cell stack, the size of the separable base plate311is increased in a direction in which the battery cells are stacked in proportion to the increased distance between the leg members in the direction in which the battery cells are stacked.

In an embodiment, each of the sliding movement members may be a sliding rail including a fixed first rail and a movable second rail movable on the first rail, and the stopper member may be configured to have a concave-convex structure corresponding to the first rail and the second rail.

In another embodiment, each of the sliding movement members may be a sliding rail including a fixed first rail and a movable second rail movable on the first rail, and the stopper member may include an elastic protrusion formed at the first rail and fastening grooves formed at the second rail at regular intervals such that the elastic protrusion is coupled into a corresponding one of the fastening grooves.

In another embodiment, the stopper member may be configured to have a concave-convex structure, the stopper member being mounted in the module case, and each of the sliding movement members may be a wheel member coupled to a lower end of a corresponding one of the leg members, the wheel member being moveable on the stopper member having the concave-convex structure.

In a further embodiment, each of the sliding movement members may be a wheel member coupled to a lower end of a corresponding one of the leg members, and the stopper member may be a compression elastic member connected between the leg members coupled to the opposite ends of the separable base plate.

Specifically, the compression elastic member may be a compression spring.

The movable pressurization member may release expansion stress of battery cells constituting the battery cell stack for uniformly maintaining pressure applied to the respective battery cells.

The pressure may be maintained within a range of 30 kgf to 80 kgf. If the pressure is lower than 30 kgf, it is not possible to sufficiently restrain swelling of the battery cells. On the other hand, if the pressure is higher than 80 kgf, the battery cells may be damaged due to such excessive pressure. For this reason, the movable pressurization member may maintain pressure applied to the battery cells within the above-defined range.

The battery cell stack may include a plurality of battery cells, and each of the battery cells may be a pouch-shaped battery cell configured to have a structure in which an electrode laminate is mounted in a battery case together with an electrolyte in a sealed state.

In accordance with another aspect of the present invention, there is provided a battery pack including the battery module with the above-stated construction as a unit module.

In accordance with a further aspect of the present invention, there is provided a device including the battery pack as a power source. Specifically, the device may be any one selected from a group consisting of a mobile phone, a portable computer, a smart phone, a smart pad, a netbook computer, a light electronic vehicle (LEV), an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a power storage device.

The structure and manufacturing method of the device are well known in the art to which the present invention pertains, and therefore a detailed description thereof will be omitted.

BEST MODE

FIG. 1is a typical view showing a battery module according to an embodiment of the present invention.

Referring toFIG. 1, a battery module10includes a module case100, a battery cell stack200, and a movable pressurization member300.

The movable pressurization member300includes a support member310, sliding movement members320, and a stopper member330.

The support member310includes a separable base plate311and leg members312.

Each of the sliding movement members320is coupled to the lower end of a corresponding one of the leg members312. Each of the sliding movement members320is configured to have a wheel structure. Consequently, the sliding movement members320may be moved on the stopper member330.

The stopper member330is configured to have a concave-convex structure. Consequently, the stopper member330may stop the movement of the sliding movement members320by stages.

When the battery cell stack200swells due to gas generated from the battery cell stack200, pressure is applied from the battery cell stack200to the leg members312. As a result, the sliding movement members320connected to the respective leg members312are moved away from each other in right and left directions on the stopper member330. In addition, the separable base plate311is configured to have a structure in which the size of the separable base plate311is increased as the distance between the leg members312is increased due to swelling of the battery cell stack200. In this structure, the pressure applied to the battery cell stack200is uniformly maintained.

INDUSTRIAL APPLICABILITY

As is apparent from the above description, a battery module according to the present invention includes a movable pressurization member that is capable of pressurizing a battery cell stack, thereby uniformly maintaining the pressure of battery cells and preventing leakage of an electrolyte.