Battery module and battery pack comprising same

The present disclosure relates to a battery module, which includes: a housing including a first housing and a second housing, which are coupled to each other to form a accommodation space; a plurality of secondary batteries accommodated in the accommodation space; a bolt including a screw portion, which has screw threads formed on at least a portion of an outer circumferential surface thereof, and a bolt head arranged at an end of the screw portion, the bolt being configured to fasten the first housing and the second housing to each other by being mounted such that the screw portion penetrates the first housing to be screw-coupled to the second housing, and that the bolt head is caught by the first housing; and an O-ring mounted to be interposed between the first housing and the bolt head, wherein the O-ring includes: a hollow pierced such that the screw portion is inserted therein; and a recognition protrusion formed to protrude in a radial direction of the bolt head as compared with the bolt head.

TECHNICAL FIELD

The present disclosure relates to a battery module and a battery pack including the same.

The present application claims priority to Korean Patent Application No. 10-2016-0015160 filed on Feb. 5, 2016 in the Republic of Korea, the disclosure of which is incorporated herein by reference.

BACKGROUND ART

Recently, as the demand for portable electronic products such as notebooks, video cameras, mobile phones, and the like is rapidly increased, and the development of electric vehicles, energy storage batteries, robots, satellite, and the like is accelerated, high-performance secondary batteries capable of being repeatedly charged and discharged are being actively studied.

Currently commercialized secondary batteries include nickel cadmium batteries, nickel metal hydride batteries, nickel zinc batteries, lithium secondary batteries, and the like. Among these secondary batteries, since lithium secondary batteries have advantages of being freely charged and discharged due to almost no memory effect as compared with nickel-based batteries and having extremely low self-discharge rate and high energy density, lithium secondary batteries are spotlighted.

Such lithium secondary batteries mainly include a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively. Lithium secondary batteries include an electrode assembly, in which a positive electrode plate and a negative electrode plate respectively coated with a positive electrode active material and an negative electrode active material are arranged with a separator therebetween, and an exterior, that is, a battery case, in which the electrode assembly and an electrolyte are sealed and accommodated.

Generally, depending upon shapes of exteriors, lithium secondary batteries may be classified into can-type secondary batteries, in which an electrode assembly is embedded in a metal can, and pouch-type secondary batteries, in which an electrode assembly is embedded in a pouch of an aluminum laminate sheet.

Recently, secondary batteries are widely used in medium and large-sized devices such as automobiles or power storage devices as well as in small-sized devices such as portable electronic devices. When secondary batteries are used in medium and large-sized devices, a large number of secondary batteries are electrically connected to each other for improving capacity and output. In particular, pouch-type secondary batteries are frequently used in medium and large-sized devices due to a merit of being easily accommodated and stacked.

FIG. 1is a schematic diagram illustrating a battery module according to the related art.

As such, a battery module1may refer to a component in which a large number of secondary batteries22are connected in series or parallel for improving capacity, output, and the like. Generally, the battery module1includes a case10accommodating a secondary battery stacked body20in which the large number of secondary batteries22are stacked. In addition, as shown inFIG. 1, the case10includes an upper case12accommodating an upper portion of the secondary battery stacked body20and a lower case14accommodating a lower portion of the secondary battery stacked body20, and the upper case12and the lower case14are fastened to each other by a bolt30. As shown inFIG. 1, the bolt30is mounted such that a screw portion32is inserted into a bolt hole16pierced in the upper case12and screw-coupled to the lower case14, and that a bolt head34is caught by the upper case12, thereby fastening the upper case12and the lower case to each other.

However, when internal gas is generated from the secondary batteries22during charge-discharge of the secondary batteries22, there is a concern that the internal gas of the secondary batteries22is leaked outside the battery module1through the bolt hole16of the upper case12. To solve this problem, in the battery module1according to the related art, an O-ring40is mounted to be interposed between the bolt head34and the upper case12, thereby sealing the bolt hole16. The O-ring40is mounted for the screw portion32of the bolt30to be inserted into a hollow thereof, and thus is interposed between the bolt head34and the upper case12. However, since the O-ring40generally has a smaller diameter than the bolt head34, the bolt30needs to be separated from the bolt hole16for inspecting whether the O-ring40is mounted. Therefore, in the battery module1according to the related art, there are problems in that a lot of time is required for inspecting whether the O-ring40for sealing the bolt hole16is mounted, and that there is a concern of occurrence of errors in inspection results due to a complicated method of inspecting whether the O-ring40is mounted.

In addition, since the O-ring40is generally manufactured from a synthetic material having elasticity, there are some cases in which the O-ring40is twisted to be dragged toward the center thereof due to a shear force applied between the bolt head34and the O-ring40in the process of tightening the bolt30. As such, when the O-ring40is twisted, the internal gas of the secondary batteries22may be leaked outside the battery module1through the bolt hole16, like in the case that the O-ring40is not mounted. To inspect the twist of the O-ring40, the bolt30needs to be separated from the bolt hole16, like in the case of inspecting whether the O-ring40is mounted. Therefore, in the battery module1according to the related art, there are problems in that a lot of time is required for inspecting whether the O-ring40for sealing the bolt hole16is twisted, and that there is a concern of occurrence of errors in inspection results due to a complicated method of inspecting whether the O-ring40is twisted.

DISCLOSURE

Technical Problem

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery module, which has a structure improved to easily inspect whether an O-ring for preventing leakage of internal gas of a secondary battery is mounted and whether the O-ring is twisted, and a battery pack including the battery module.

Technical Solution

In one aspect of the present disclosure, there is provided a battery module comprising: a housing comprising a first housing and a second housing, which are coupled to each other to form a accommodation space; a plurality of secondary batteries accommodated in the accommodation space; a bolt comprising a screw portion, which has screw threads formed on at least a portion of an outer circumferential surface thereof, and a bolt head arranged at an end of the screw portion, the bolt being configured to fasten the first housing and the second housing to each other by being mounted such that the screw portion penetrates the first housing to be screw-coupled to the second housing, and that the bolt head is caught by the first housing; and an O-ring mounted to be interposed between the first housing and the bolt head, wherein the O-ring comprises: a hollow pierced such that the screw portion is inserted therein; and a recognition protrusion formed to protrude in a radial direction of the bolt head as compared with the bolt head.

Preferably, the O-ring has a diameter that is equal to or less than that of the bolt head. Preferably, the recognition protrusion is formed to protrude from a circumferential surface of the O-ring in the radial direction of the bolt head.

Preferably, the first housing comprises a bolt hole pierced such that the screw portion is inserted therein, and the O-ring is interposed between the first housing and the bolt head to seal the bolt hole.

Preferably, the first housing comprises an O-ring groove formed to be recessed such that the O-ring is inserted therein.

Preferably, the O-ring groove has a recognition portion formed to extend in the radial direction of the bolt head such that the recognition protrusion is inserted therein.

In another aspect of the present disclosure, there is also provided a battery module comprising: a housing comprising a accommodation space and a bolt hole; a plurality of secondary batteries accommodated in the accommodation space; a bolt comprising a screw portion and a bolt head arranged at an end of the screw portion, the bolt being mounted such that the screw portion is inserted into the bolt hole, and that the bolt head is caught by the housing; and an O-ring mounted to be interposed between the housing and the bolt head, wherein the O-ring comprises: a hollow pierced such that the screw portion is inserted therein; and a recognition protrusion formed to protrude in a radial direction of the bolt head as compared with the bolt head.

Preferably, the O-ring has a diameter that is equal to or less than that of the bolt head.

In yet another aspect of the present disclosure, there is also provided a battery pack comprising the battery module according to the one aspect of the present disclosure as set forth above and the battery module according to the other aspect of the present disclosure as set forth above.

In yet another aspect of the present disclosure, there is also provided a vehicle comprising the battery pack according to yet the other aspect of the present disclosure as set forth above.

Advantageous Effects

According to the battery module and the battery pack including the battery module according to the present disclosure, when the O-ring is interposed between the bolt head of the bolt and the housing to seal the bolt hole of the housing, into which the screw portion of the bolt is inserted, the recognition protrusion, which protrudes in the radial direction of the bolt head as compared with the bolt head, is provided to the O-ring, whereby whether the O-ring is mounted and whether the O-ring is twisted may be checked by the recognition protrusion even without separating the bolt from the bolt hole.

BEST MODE

It should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. Therefore, since embodiments described herein and configurations shown in the drawings are merely preferable examples and do not represent all technical aspects of the present disclosure, it should be understood that various equivalents and modified examples could be made without departing from the scope of the disclosure.

In the drawings, the size of each component or the size of a specific portion constituting each component may be exaggerated, omitted, or schematically illustrated for convenience and clarity. Therefore, the size of each component does not completely reflect the actual size thereof. When it is determined that descriptions of relevant functions or configurations known in the art may unnecessarily obscure the gist of the present disclosure, such descriptions will be omitted.

FIG. 2is a plan view illustrating a battery module according to a preferred embodiment of the present disclosure,FIG. 3is a partial cross-sectional view of the battery module ofFIG. 2, taken along a line I-I′, andFIG. 4is a partial cross-sectional view of the battery module ofFIG. 3, taken along a line II-II′.

Referring toFIGS. 2 and 3, a battery module100according to a preferred embodiment of the present disclosure includes: a housing110including a first housing111and a second housing112, which are coupled to each other to form a accommodation space113; a secondary battery stacked body120, which is obtained by stacking a plurality of secondary batteries122in multiple layers and is accommodated in the accommodation space113of the housing110; a bolt130including a screw portion132, which penetrates the first housing111to be screw-coupled to the second housing112, and a bolt head134caught by the first housing111, the bolt130being configured to fasten the first housing111and the second housing112to each other; and an O-ring140interposed between the bolt head134and the first housing111to prevent internal gas generated from the secondary batteries122from being leaked from the accommodation space of the housing110.

A plurality of battery modules100may be connected in a predetermined electrical connection method and constitute a battery pack. In addition, the battery pack may be mounted and used in vehicles.

First, the housing110is a member for protecting the secondary batteries122from an outside thereof.

As shown inFIG. 2, the housing110is arranged to surround the secondary battery stacked body120, and a battery management system (BMS) and other various members may be mounted on an outer surface of the housing110. As shown inFIG. 3, the housing110includes the first housing111and the second housing112, which are provided in the manner of being decouplable from and couplable to each other and form the accommodation space113for accommodating the secondary battery stacked body120.

As shown inFIG. 3, the first housing111is arranged to surround an upper portion of the secondary battery stacked body120. As shown inFIG. 3, the first housing111includes a first bolt hole114pierced such that the screw portion132of the bolt130is inserted therein, and an O-ring groove115formed to be recessed such that the O-ring140is at least partially inserted therein.

As shown inFIG. 3, the first bolt hole114is formed by perforating the first housing111in an up-down direction such that the screw portion132of the bolt130is inserted into the first bolt hole114. The first bolt hole114provides a path for the screw portion132of the bolt130to penetrate the accommodation space113and extend to the second housing112.

As shown inFIG. 4, the O-ring groove115has a shape corresponding to the O-ring140for the O-ring140to be at least partially inserted into the O-ring groove115, and is formed to be recessed on an upper surface of the first housing111to surround the first bolt hole114. The O-ring groove115supports the O-ring140such that the O-ring140interposed between the bolt head134of the bolt130and the upper surface of the first housing111is not moved.

In addition, as shown inFIG. 4, the O-ring groove115includes a recognition portion115aformed to extend such that a recognition protrusion144of the O-ring140described below is inserted into the recognition portion115a. The recognition portion115ais formed to extend from one side of the O-ring groove115in a radial direction of the bolt head134, that is, in a radial direction of the O-ring140.

As shown inFIG. 3, the second housing112is arranged to surround a lower portion of the secondary battery stacked body120. As shown inFIG. 3, the second housing112includes a second bolt hole116pierced such that a lower end of the screw portion132extending to the second housing112is screw-coupled thereto.

As shown inFIG. 3, the second bolt hole116is preferably formed on an upper surface of the second housing112such that only an upper portion of the second bolt hole116is opened and a lower portion thereof is closed, without being limited thereto.

Next, the secondary battery stacked body120is a member for providing electric power.

As shown inFIG. 3, the secondary battery stacked body120includes the plurality of secondary batteries122and a plurality of cartridges124, each of the plurality of cartridges124accommodating at least one of the secondary batteries122.

Each of the secondary batteries122preferably includes a lithium polymer battery. However, the present disclosure is not limited thereto, and each of the secondary batteries122may include a lithium ion battery, a nickel cadmium battery, a nickel metal hydride battery, a nickel zinc battery, or the like.

Each of the secondary batteries122is preferably configured in a pouch type. However, the present disclosure is not limited thereto, and each of the secondary batteries122may be configured in a cylindrical type, an rectangular type, or the like.

Each of the cartridges124accommodates and holds at least one of the secondary batteries122, and thus prevents movements of the secondary batteries122. In addition, as shown inFIG. 3, the cartridges124may be mounted to be penetrated by the screw portion132of the bolt130, and thus secured by the screw portion132of the bolt130. The cartridges124are configured to be stackable on each other such that the secondary batteries122may be easily stacked and assembled. Thus, the cartridges124are stacked in multiple layers and thus form the secondary battery stacked body120.

FIG. 4is a partial cross-sectional view of the battery module ofFIG. 3, taken along a line II-II′.

Next, the bolt130is a member for fastening the first housing111and the second housing112to each other.

As shown inFIG. 3, the bolt130includes the screw portion132, which has screw threads formed on at least a portion of an outer circumferential surface thereof, and the bolt head134arranged at an end of the screw portion132.

The screw portion132has a predetermined length such that the lower end of the screw portion132sequentially passes through the first bolt hole114and the accommodation space113in this stated order and is screw-coupled to the second bolt hole116. Although screw threads132aof the screw portion132are preferably formed only on an outer circumferential surface of the lower end of the screw portion132, which is screw-coupled to the second bolt hole116, the present disclosure is not limited thereto.

The bolt head134is arranged at an upper end of the screw portion132, and has a larger diameter than the first bolt hole114not to be inserted into the first bolt hole114.

As shown inFIG. 3, the bolt130may be mounted such that the screw portion132is screw-coupled to the second bolt hole116, and that the bolt head134is caught by the upper surface of the first housing111, thereby fastening the first housing111and the second housing112to each other.

Next, the O-ring140is a member for preventing the internal gas of the secondary batteries122from being leaked out of the housing110.

The O-ring140is preferably formed of a synthetic resin material having elasticity, without being limited thereto. As shown inFIG. 4, the O-ring140includes a hollow142pierced such that the screw portion132is inserted therein, and the recognition protrusion144formed to protrude in the radial direction of the bolt head134as compared with the bolt head134. In addition, as shown inFIG. 4, the recognition protrusion144is preferably formed to protrude from a circumferential surface of the O-ring140, without being limited thereto.

The O-ring140is mounted in the O-ring groove115to be interposed between a bottom surface of the bolt head134and the upper surface of the first housing111, and the recognition protrusion144is mounted to be inserted into the recognition portion115aof the O-ring groove115. Then, the O-ring140may seal the first bolt hole114and thus prevent the internal gas generated from the secondary batteries122from being leaked out of the housing110through the first bolt hole114.

In the case that the O-ring140is normally mounted, when the upper surface of the first housing111is viewed from an outside of the battery module100, the recognition protrusion144is accommodated in the recognition portion115ato protrude in the radial direction of the bolt head134as compared with the bolt head134. On the other hand, in the case that the O-ring140is not mounted due to process errors or other causes or is twisted due to a shear force applied upon mounting the bolt130, when the upper surface of the first housing111is viewed from the outside of the battery module100, the recognition protrusion144is not accommodated in the recognition portion115aor is only partially accommodated in the recognition portion115a. Therefore, in the battery module100, since whether the O-ring140is mounted and whether the O-ring140is twisted may be simultaneously checked by the recognition protrusion144even without separating the bolt130from the first bolt hole114, productivity may be improved.

Although, when the bolt130is mounted for fastening the first housing111and the second housing112to each other, the O-ring140has been described as being interposed between the first housing11and the bolt head134of the bolt130and being used to seal the first bolt hole114of the first housing111, into which the screw portion132of the bolt130is inserted, the present disclosure is not limited thereto. That is, when a bolt (not shown) different from the bolt130set forth above is mounted in the housing110for purposes other than the purpose of fastening the first housing111and the second housing112to each other, the O-ring140may be interposed between the housing110and a bolt head (not shown) of the bolt and be used to seal a bolt hole (not shown) of the housing110, into which a screw portion (not shown) of the bolt is inserted. Therefore, even in this case, like in the case of the bolt130set forth above, whether the O-ring140is mounted and whether the O-ring140is twisted may be simultaneously checked by the recognition protrusion144even without separating the bolt from the bolt hole.

Heretofore, although the present disclosure has been described with reference to specific embodiments in conjunction with the accompanying drawings, it should be understood that the present disclosure is not limited by these embodiments, and that various modifications, changes, and equivalent embodiments can be made by those skilled in the art without departing from the scope of the present disclosure.

INDUSTRIAL APPLICABILITY

The present disclosure relates to a battery module and a battery pack including the battery module, and the battery module and the battery pack as set forth above may be particularly applied to industries related to secondary batteries.