Patent Description:
Required capacities of secondary batteries used as energy sources of various kinds of electronic devices inevitably used in modern society have been increased due to an increase in usage of mobile devices, increasing complexity of the mobile devices, and development of electric vehicles. In order to satisfy demand of users, a plurality of battery cells is disposed in a small-sized device, whereas a battery module including a plurality of battery cells electrically connected to each other or a battery pack including a plurality of battery modules is used in a vehicle.

In a battery module, a plurality of battery cells is connected to each other in series and in parallel, whereby the capacity and output of the battery module are increased. In general, the battery module includes a busbar configured to electrically connect the battery cells to each other and a connection busbar configured to connect a plurality of busbars to each other.

<FIG> is an upper perspective view of a conventional battery module, <FIG> is a perspective view of a conventional busbar and a conventional busbar frame, <FIG> is a perspective view of the conventional busbar frame and a conventional end cover, and <FIG> is a side sectional view of the conventional battery module.

The conventional battery module includes a busbar <NUM>, to which electrode leads protruding from an electrode assembly are connected, a busbar frame <NUM> configured to fix the busbar <NUM>, and a connection busbar <NUM> configured to electrically connect one or more busbars <NUM> to each other.

In general, the busbar <NUM> and the connection busbar <NUM> are connected to each other by joining, bolt fastening, or fitting. In the present invention, however, a connection bolt <NUM> is provided in order to couple the busbar <NUM> and the connection busbar <NUM> to each other, whereby the force of fixing between the busbar <NUM> and the connection busbar <NUM> is increased.

The busbar <NUM> includes a slit <NUM> configured to allow each of the electrode leads to extend therethrough, an electrode lead connection portion <NUM>, to which the portion of the electrode lead extending through the slit <NUM> is coupled, and a terminal portion <NUM> configured to connect the busbar <NUM> and the connection busbar <NUM> to each other.

The terminal portion <NUM> may protrude from the electrode lead connection portion <NUM> and may then be bent. The terminal portion <NUM> is provided with a fixing hole for connection with the connection busbar <NUM>. The connection bolt <NUM> extends through the fixing hole of the terminal portion <NUM> and a bolt hole of the connection busbar <NUM>, and is then coupled to a connection nut <NUM> integrally formed at the busbar frame <NUM>, which is coupled to an end cover <NUM>.

The connection nut <NUM> is located at a bolt receiving portion <NUM> of the busbar frame <NUM>. In order to integrally form the connection nut <NUM> and the busbar frame <NUM>, a process of integrating the connection nut <NUM> and the busbar frame <NUM> is required.

In particular, a predetermined strength is required for the connection nut <NUM> in order to achieve coupling between the connection bolt <NUM> and the connection nut <NUM>. Consequently, the connection nut must be made of a material different from the material for the busbar frame <NUM>, and therefore it is difficult to manufacture the connection nut.

Furthermore, the busbar frame <NUM> must also have a predetermined thickness due to the connection nut <NUM>, and a separate space for the connection nut <NUM> is necessary.

In Patent Document <NUM>, a rivet is located at a resistance weld region between an electrode lead and an electrode terminal in order to connect the electrode lead and the electrode terminal to each other. However, since a female rivet and a male rivet are used, there is a problem in that a separate space for receiving the rivets is required. In addition, it has a disadvantage in that the force of fixing may be reduced when the force of fixing between the female rivet and the male rivet is reduced.

Therefore, there is a necessity for technology capable of reducing a space for fixing while providing predetermined coupling force when a busbar and a connection busbar are connected to each other.

<CIT> and <CIT> disclose a battery pack.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a battery module capable of fixing a busbar and a connection busbar to each other using a single fixing means while reducing a fixing space and fixing expense.

In order to accomplish the above object, a battery module according to the present invention includes at least one busbar that electrically connects electrode leads protruding from an electrode assembly; a busbar frame connected to the busbar, the busbar being fixed to the busbar frame; a connection busbar connected to the at least one busbar; and a connection bolt connecting the busbar and the connection busbar together, wherein the busbar includes a screw thread configured to fix the connection bolt.

The busbar includes a slit having each of the electrode leads extended therethrough, an electrode lead connection portion fixing the electrode lead, and a terminal portion connected to the connection busbar, and the terminal portion includes a fixing hole configured to be coupled to the connection busbar by the connection bolt, the fixing hole including a screw thread configured to fix the connection bolt.

No separate nut configured to fix the connection bolt is included.

The thickness of the terminal portion is greater than the thickness of the electrode lead connection portion.

The terminal portion may include two or more layers.

The terminal portion may be bent using a hemming method.

The screw thread may be formed in all of the two or more layers of the terminal portion.

No separate space may be provided between the two or more layers.

A portion of the busbar excluding the terminal portion may be compressed, whereby the thickness of the remaining portion of the busbar, i.e. the electrode lead connection portion, is reduced while the terminal portion is maintained thick.

A portion of the terminal portion that is connected to the electrode lead connection portion may be compressed.

The connection busbar may further include a screw thread configured to fix the connection bolt.

The busbar frame may include a bolt receiving portion receiving the end of the connection bolt extending through the busbar and the connection busbar, and the bolt receiving portion may include a fixing portion pressing the end of the connection bolt in a direction perpendicular to an insertion direction.

The fixing portion may be made of an elastic material.

The present invention provides a battery pack including the battery module or a device having the battery module mounted therein.

In the present invention, one or more constructions that do not conflict with each other may be selected and combined from among the above constructions.

As is apparent from the above description, in a battery module according to the present invention, a screw thread configured to connect a busbar and a connection busbar to each other using a connection bolt is provided in the busbar, whereby no separate nut is needed. Consequently, a separate space for receiving a connection nut is not necessary, and a process of integrally forming the connection nut at a busbar frame is not necessary.

In addition, the screw thread is provided in the busbar, and only the thickness of a terminal portion at which the busbar and the connection busbar are connected to each other is increased, whereby coupling force of the connection bolt for connecting the busbar and the connection busbar to each other is increased. In addition, a screw thread is also provided in the connection busbar in order to fix the connection bolt, and a separate fixing portion is provided at the position of a conventional nut, whereby coupling force is increased.

Furthermore, since the fixing portion is located at the position of the conventional nut, it is possible to check, through the fixing portion, whether the connection bolt is properly coupled.

<FIG> is a side sectional view of a battery module according to a first embodiment of the present invention, and <FIG> is a perspective view of a busbar according to a first embodiment of the present invention.

The battery module according to the first embodiment includes at least one busbar <NUM> configured to connect electrode leads protruding from an electrode assembly, a busbar frame <NUM> connected to the busbar <NUM>, the busbar frame being configured to fix the busbar <NUM>, a connection busbar <NUM> configured to connect the at least one busbar <NUM>, and a connection bolt <NUM> configured to connect the busbar <NUM> and the connection busbar <NUM> to each other, wherein the busbar <NUM> has a screw thread A configured to fix the connection bolt <NUM>.

The busbar <NUM> includes a slit <NUM> configured to allow each of the electrode leads to extend therethrough, an electrode lead connection portion <NUM> configured to fix the electrode lead, and a terminal portion <NUM> configured to face the connection busbar <NUM>, wherein the terminal portion <NUM> includes a fixing hole <NUM> configured to be coupled to the connection busbar <NUM> by the connection bolt <NUM>, and the fixing hole <NUM> is provided with a screw thread A configured to fix the connection bolt <NUM>.

The slit <NUM> of the busbar <NUM> is a space formed in the electrode lead connection portion <NUM>, which is a space configured to allow the electrode lead to extend therethrough.

The electrode lead protruding from the electrode assembly extends through the slit <NUM>, is bent, and is fixed to the outer surface of the electrode lead connection portion <NUM> using a well-known fixing method, such as laser welding or resistance welding.

The busbar <NUM> may connect electrode leads having the same polarity, or may connect electrode leads having different polarities, to connect the electrode assembly in series or in parallel.

The busbar <NUM> may be made of a metal material that exhibits high conductivity so as to easily move electrons transmitted by the electrode lead without loss. The electrode lead connection portion <NUM> and the terminal portion <NUM> according to the present invention are made of the same material, and are integrally formed.

The terminal portion <NUM> may be bent so as to face a direction different from a direction in which the electrode lead connection portion <NUM> faces. As an example, the terminal portion <NUM> may be bent so as to be perpendicular to the electrode lead connection portion <NUM>, as shown in <FIG>.

The terminal portion <NUM> includes a fixing hole <NUM> configured to be coupled to the connection busbar <NUM> by the connection bolt <NUM>, and the fixing hole <NUM> has a screw thread A configured to fix the connection bolt.

The fixing hole <NUM> may have the same size as the diameter of a body portion of the connection bolt <NUM> so as to fix the connection bolt <NUM>. The fixing hole <NUM> is provided in the inner surface thereof with a screw thread A in order to perform the function of a conventional connection nut, and the screw thread is coupled to a screw valley B of the connection bolt <NUM> in order to fix the connection bolt <NUM>.

It is preferable for the screw thread A to have a minimum size of <NUM> based on an M6 connection bolt. Although being changed depending on the shape of the connection bolt <NUM>, it is preferable for the screw thread A to have a size of <NUM> or more so as to be maintained in a connected state even when impact is applied to the busbar <NUM> and the connection busbar <NUM>.

To this end, in the busbar <NUM> according to the first embodiment of the present invention, the thickness of the terminal portion <NUM> at which the fixing hole <NUM> is located may be <NUM> or more. If the busbar <NUM> is too thick, however, the object of the present invention of securing a space by removing the connection nut is not accomplished. In the busbar <NUM> according to the present invention, therefore, the portion of the busbar <NUM> excluding the terminal portion <NUM> is compressed, whereby the thickness of the remaining portion of the busbar <NUM>, i.e. the electrode lead connection portion <NUM>, is reduced while the terminal portion <NUM> is maintained thick, and therefore the portion included in the battery module may be maintained thin.

In addition, a portion of the terminal portion <NUM> at which the terminal portion <NUM> and the electrode lead connection portion <NUM> are connected to each other may be compressed, whereby the portion excluding the portion configured to fix the busbar <NUM> and the connection busbar <NUM> may be maintained so as to perform only the function thereof.

The busbar frame <NUM> also performs a function of preventing the busbar <NUM> from contacting another member while fixing the busbar <NUM>. The busbar frame <NUM> according to the present invention may perform a function of fixing the portion of the busbar <NUM> corresponding to the lower surface of the terminal <NUM>. The surface of the terminal portion <NUM> that does not face the connection busbar <NUM>, i.e. the lower surface of the terminal portion <NUM>, faces the busbar frame <NUM>. A predetermined protrusion is formed on the lower surface of the terminal portion <NUM>, and the protrusion may be fixed to the corresponding portion of the busbar frame <NUM>, or may be fixed by joining or fitting. At this time, the busbar frame <NUM>, to which the terminal portion <NUM> is fixed, may be a busbar frame different from the busbar frame <NUM> configured to fix the terminal portion <NUM>, e.g. a busbar frame coupled to an end cover.

The connection busbar <NUM> connects the busbar <NUM> to an external device, or connects two or more busbars <NUM> to each other. The portion of the connection busbar <NUM> that contacts the busbar <NUM> may be made of a conductive metal so as to move electricity transmitted by the busbar <NUM>, and the outer surface of the portion of the connection busbar that does not contact the busbar <NUM> may be wrapped with an insulating material.

The connection bolt <NUM> may include a head portion configured to have a diameter greater than the diameter of a bolt hole <NUM> of the connection busbar <NUM> and the diameter of the fixing hole <NUM> of the busbar <NUM> so as to be fixed to one surface of the connection busbar <NUM> and a body portion configured to extend through the bolt hole <NUM> of the connection busbar <NUM> and the fixing hole <NUM> of the busbar <NUM>, the body portion being provided with a screw valley B configured to be engaged with a screw thread formed in the bolt hole <NUM> of the connection busbar <NUM> and the screw thread of the fixing hole <NUM> of the busbar <NUM>.

The connection bolt <NUM> may be made of a conductive material so as to transmit electricity while being united with the busbar <NUM> and the connection busbar <NUM>.

The electrode assembly, the busbar <NUM>, the busbar frame <NUM>, and the connection busbar <NUM> are received in a module case so as to be protected from external impact. As an example, the module case may include a lower case, the lower surface and the side surfaces of which are surrounded by plates, the lower case having a predetermined space configured to receive the electrode assembly, etc., and an upper case configured to cover the lower case. As needed, the module case may include a flat lower case configured to allow the electrode assembly, etc. to be seated thereon and an upper case, the side surfaces and the upper surface of which are hermetically sealed so as to wrap battery cell including the electrode assembly, etc..

Meanwhile, the upper case and the lower case may be fixed and assembled to each other using a well-known fixing method, such as interference fitting, bolt fastening, or welding.

<FIG> is a side sectional view of a battery module according to a second embodiment of the present invention, and <FIG> is a perspective view of a busbar according to a second embodiment of the present invention.

The second embodiment of the present invention is identical to the first embodiment except for the shape of the terminal portion <NUM> of the busbar <NUM>. The initial thickness of the terminal portion <NUM> of the busbar <NUM> according to the second embodiment of the present invention may be equal to the thickness of the electrode lead connection portion <NUM>. The terminal portion <NUM> may be bent using a hemming method so as to have two or more layers such that the terminal portion <NUM> has a predetermined thickness. At this time, the length of an upper terminal portion <NUM>(a) of the terminal portion <NUM> may be greater than the length of a lower terminal portion <NUM>(b), or may be equal to the length of the lower terminal portion <NUM>(b).

A hemmed portion H formed using the hemming method, as described above, is configured to have a shape capable of being seated in the busbar frame <NUM>, and is coupled to a corresponding portion of the busbar frame <NUM>.

The portion of the lower terminal portion <NUM> (b) corresponding to the busbar frame <NUM> may be partially deformed, whereby the force of coupling with the busbar frame <NUM> may be improved.

In the busbar <NUM> according to the second embodiment of the present invention, only the lower terminal portion <NUM>(b) may be provided with a screw thread A, or both the upper terminal portion <NUM>(a) and the lower terminal portion <NUM>(b) may be provided with a screw thread A.

In the case in which only the lower terminal portion <NUM>(b) is provided with a screw thread, there is an advantage in that a region to be processed is reduced. However, it is preferable for both the upper terminal portion <NUM>(a) and the lower terminal portion <NUM>(b) to be provided with a screw thread A in order to increase coupling force.

At this time, although it is preferable that no space be provided between the upper terminal portion <NUM>(a) and the lower terminal portion <NUM>(b), an attachment sheet may be disposed in a space S between the upper terminal portion <NUM>(a) and the lower terminal portion <NUM>(b) in order to increase the force of fixing with the connection bolt <NUM> while preventing the upper terminal portion <NUM>(a) and the lower terminal portion <NUM>(b) from being separated from each other.

<FIG> is a perspective view showing the connection relationship between the busbar according to the second embodiment of the present invention, the connection busbar, and the connection bolt.

As can be seen from <FIG>, the terminal portion <NUM> of the busbar according to the present invention and the connection busbar <NUM> are fixed by the connection bolt <NUM>.

At this time, a screw thread C may be provided in the bolt hole <NUM> of the connection busbar <NUM> in order to increase the force of coupling between the connection busbar <NUM> and the connection bolt <NUM>.

The connection bolt <NUM> extends through a fixing hole <NUM> located at each of the upper terminal portion <NUM>(a) and the lower terminal portion <NUM>(b) and a bolt hole <NUM> of the connection busbar <NUM>. A screw valley B of the connection bolt <NUM> is fixed by the screw thread A of the fixing hole <NUM> and the screw thread C of the bolt hole <NUM>. At this time, the terminal portion <NUM> and the connection busbar <NUM> are coupled to the connection bolt <NUM> in a fixed state such that the position of the screw thread A of the fixing hole <NUM> and the screw thread C of the bolt hole <NUM> is not changed.

<FIG> is a sectional view of a battery module according to a third embodiment of the present invention. The third embodiment of the present invention is identical to the second embodiment except that a bolt receiving portion <NUM> of the busbar frame <NUM> is provided with a fixing portion <NUM>. The fixing portion <NUM> may also be provided in the first embodiment.

The busbar frame <NUM> according to the third embodiment is provided with a bolt receiving portion <NUM> configured to receive the end of the connection bolt <NUM> after extending through the terminal portion <NUM> and the connection busbar <NUM>. The bolt receiving portion <NUM> may have only a space capable of receiving the end of the connection bolt <NUM>. At this time, the bolt receiving portion <NUM> may include a fixing portion <NUM> configured to push the end of the connection bolt <NUM> in a direction perpendicular to an insertion direction in order to increase the force of fixing to the connection bolt <NUM>.

The fixing portion <NUM> may be made of an elastic material so as to prevent separation of the connection bolt <NUM>.

The fixing portion <NUM> may be made of an elastic material, a spring may be mounted to the surface of the fixing portion <NUM> that does not face the connection bolt <NUM>, and a member configured to fix the connection bolt <NUM> may be mounted to the surface of the fixing portion <NUM> that faces the connection bolt <NUM>, as shown in <FIG>.

It is possible to check, through the fixing portion <NUM>, whether the connection bolt <NUM> extends through the terminal portion <NUM> and is properly coupled thereto. When the end of the connection bolt <NUM> is coupled to the fixing portion <NUM>, it is possible to check the position of the connection bolt <NUM> through a change of the physical position of the fixing portion <NUM> by the connection bolt <NUM>.

Meanwhile, the present invention provides a battery pack including the battery module, and the battery module or the battery pack may be used in a device.

Claim 1:
A battery module comprising:
at least one busbar (<NUM>) that electrically connects electrode leads protruding from an electrode assembly;
a busbar frame (<NUM>) connected to the busbar (<NUM>), the busbar (<NUM>) being fixed to the busbar frame (<NUM>);
a connection busbar (<NUM>) connected to the at least one busbar (<NUM>); and
a connection bolt (<NUM>) connecting the busbar (<NUM>) and the connection busbar (<NUM>) together,
wherein the busbar (<NUM>) comprises a screw thread (A) configured to fix the connection bolt (<NUM>),
wherein the busbar (<NUM>) comprises:
a slit (<NUM>) having each of the electrode leads extended therethrough;
an electrode lead connection portion (<NUM>) fixing the electrode lead; and
a terminal portion (<NUM>) connected to the connection busbar (<NUM>),
wherein the terminal portion (<NUM>) comprises a fixing hole (<NUM>) configured to be coupled to the connection busbar (<NUM>) by the connection bolt (<NUM>), the fixing hole (<NUM>) comprising a screw thread (A) configured to fix the connection bolt (<NUM>),
wherein no separate nut to fix the connection bolt is included,
wherein a thickness of the terminal portion (<NUM>) is greater than a thickness of the electrode lead connection portion (<NUM>).