Patent Description:
The present invention relates to a method of manufacturing a battery module capable of preventing chain ignition, and more particularly to a method of manufacturing a battery module capable of preventing chain ignition configured such that heat transfer to adjacent battery cells is inhibited and the weight of the battery module is reduced.

With recent development of alternative energies due to air pollution and energy depletion caused as the result of use of fossil fuels, demand for secondary batteries capable of storing electrical energy that is produced has increased. The secondary batteries, which are being capable of being charged and discharged, are intimately used in daily life. For example, the secondary batteries are used in mobile devices, electric vehicles, and hybrid electric vehicles.

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 the battery module or the battery pack, a plurality of battery cells is connected to each other in series or in parallel in order to increase capacity and output of the battery module or the battery pack. In the case in which a plurality of battery cells is used in a state of being connected to each other, a problem, such as overload, may occur.

In order to solve this problem, a battery module including a module case capable of inhibiting transfer of heat generated in a specific battery cell to another battery cell adjacent thereto has been developed.

<FIG> is a perspective view showing a conventional battery module. As shown in <FIG>, the conventional battery module <NUM> includes a plurality of battery cells <NUM>, a module case <NUM> configured to receive the plurality of battery cells <NUM> therein, and a filler <NUM> configured to wrap the plurality of battery cells <NUM> and to fill spaces among the battery cells <NUM>.

In the conventional battery module, the filler <NUM> is formed among the battery cells <NUM> received in the module case <NUM>, whereby the battery cells <NUM> are disposed spaced apart from each other by a predetermined distance. Consequently, there is an effect that it is possible to inhibit movement of heat generated in a specific battery cell <NUM> to another battery cell <NUM> adjacent thereto, whereby it is possible to improve safety of the battery module.

Since the battery cells <NUM> are disposed adjacent to each other, however, filling using the filler <NUM> is not easy. Furthermore, in the case in which an empty space is generated, it is not possible to sufficiently inhibit heat transfer, and the battery cells are not securely fixed, whereby the battery cells <NUM> may move even due to weak external impact, which may lead to a major accident.

Further prior art is described in <CIT>, <CIT>, <CIT>, and <CIT>.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method of manufacturing a battery module capable of preventing chain ignition configured such that movement of heat generated in any one of a plurality of battery cells received in the battery module to another battery cell adjacent thereto is inhibited and that the battery cells are securely fixed.

It is another object of the present invention to provide a method of manufacturing a battery module capable of preventing chain ignition such that energy density of the battery module is high while the weight of the battery module is reduced.

It is a further object of the present invention to provide a method of manufacturing a battery module capable of preventing chain ignition such that manufacturing time is reduced and a product defect rate is reduced.

A method of manufacturing a battery module capable of preventing chain ignition according to the present invention to accomplish the above objects includes a step of preparing a module case (<NUM>) having a plurality of receiving portions (<NUM>) formed therein, each of the receiving portions having a space of a predetermined size; a step of receiving a battery cell (<NUM>) in each of the receiving portions (<NUM>); and a step of performing heating to a predetermined temperature to fix the battery cell (<NUM>), wherein the module case (<NUM>) includes a lower plate (<NUM>), a plurality of side plates (<NUM>), and a plurality of partition walls (<NUM>) configured to form the receiving portions (<NUM>), and each of the partition walls (<NUM>) includes a lower partition wall (<NUM>(a)) extending from the lower plate (<NUM>) by a predetermined height and an upper partition wall (<NUM>(b)) extending from the lower partition wall (<NUM>(a)) by a predetermined height, wherein the lower partition wall (<NUM>(a)) and the upper partition wall (<NUM>(b)) are made of different materials, wherein each of the lower plate (<NUM>), the side plates (<NUM>), and the lower partition walls (<NUM>(a)) of the module case (<NUM>) is made of a thermoplastic resin, and the upper partition walls (<NUM>(b)) are made of a thermosetting resin.

Also, in the battery module manufacturing method according to the present invention, the thermoplastic resin may be a modified polyphenylene ether (mPPE) or a polycarbonate (PC), and the thermosetting resin may be at least one of silicon, epoxy, and polyurethane.

Also, in the battery module manufacturing method according to the present invention, the upper partition wall (<NUM>(b)) may further include glass bubbles.

In addition, the present invention provides a battery pack having received therein a battery module (<NUM>) manufactured through the manufacturing method having one or more of the features mentioned above.

In addition, the present invention provides a device having the above battery pack mounted therein.

As is apparent from the above description, a method of manufacturing a battery module capable of preventing chain ignition has a merit in that battery cell receiving portions are formed in a module case in advance, an adhesive member is injected into the receiving portions, and battery cells are received and fixed in the receiving portions, whereby it is possible to greatly reduce manufacturing time.

In addition, the method of manufacturing the battery module capable of preventing chain ignition has an advantage in that the thermosetting adhesive member injected into the receiving portions in advance uniformly wraps the outer surfaces of the battery cells in a battery cell receiving process, whereby it is possible to securely fix the battery cells, and therefore impact resistance of the battery module is high.

Furthermore, the method of manufacturing the battery module capable of preventing chain ignition has an advantage in that glass bubbles are included in a partition wall configured to partition the battery cells from each other, whereby it is possible to reduce the weight of the battery module, and a thermosetting resin, which is relatively expensive, is less used, whereby it is possible to reduce manufacturing cost.

In the case in which one part is said to be connected to another part in the entire specification, not only may the one part be directly connected to the other part, but also, the one part may be indirectly connected to the other part via a further part.

Hereinafter, a method of manufacturing a battery module capable of preventing chain ignition according to the present invention will be described with reference to the accompanying drawings.

<FIG> is a perspective view of a battery module according to a preferred embodiment of the present invention, and <FIG> is a sectional view taken along line A-A' of <FIG>.

Referring to <FIG> and <FIG>, the battery module <NUM> according to the present invention includes a module case <NUM>, an adhesive member <NUM>, and a plurality of battery cells <NUM> received in the module case <NUM>.

First, the module case <NUM>, which has an approximately hexahedral external shape, includes a flat lower plate <NUM> and four side plates <NUM> extending upwards perpendicularly from the edge of the lower plate <NUM> so as to provide a space in which the plurality of battery cells <NUM> is received in a state of being spaced apart from each other by a predetermined distance.

Here, each of the lower plate <NUM> and the four side plates <NUM> may be made of a thermoplastic resin that exhibits predetermined strength in order to protect the received battery cells <NUM> from external impact, such as modified polyphenylene ether (mPPE) or polycarbonate (PC). However, the material for each plate is not particularly restricted as long as the plate is capable of achieving the same purpose and function.

In addition, a partition wall <NUM> is provided in the space defined by the lower plate <NUM> and the side plates <NUM> in order to form a plurality of receiving portions in which the battery cells <NUM> are separately received. The partition wall <NUM> includes a lower partition wall <NUM>(a) extending from the lower plate <NUM> by a predetermined height and an upper partition wall <NUM>(b) extending from the lower partition wall <NUM>(a) by a predetermined height.

Here, it is preferable for the lower partition wall <NUM>(a) to be made of the same material as the lower plate <NUM>, i.e. a thermoplastic resin, such as modified polyphenylene ether (mPPE) or polycarbonate (PC), whereas it is preferable for the upper partition wall <NUM>(b) to be made of a thermosetting resin that exhibits low thermal conductivity and high heat resistance, e.g. at least one of silicon, epoxy, and polyurethane.

Consequently, a portion of the lower side of each received battery cell <NUM> is supported by the lower partition wall <NUM>(a), which exhibits high stiffness, and heat transfer from the battery cell to another battery cell adjacent thereto may be minimized by the upper partition wall <NUM>(b). Of course, it is obvious that the battery cell <NUM> may also be fixed and supported by the upper partition wall <NUM>(b).

Meanwhile, empty glass bubbles each having a predetermined size may be further included in the upper partition wall <NUM>(b). That is, in the case in which a thermosetting resin, such as silicon, epoxy, or polyurethane, is mixed with glass bubbles to form the upper partition wall <NUM>(b), it is possible to reduce weight of the module case <NUM>, and the thermosetting resin, which is relatively expensive, is less used, whereby it is possible to reduce manufacturing cost.

In addition, an adhesive member <NUM>, e.g. an adhesive member <NUM> made of the same material as the upper partition wall <NUM>(b), i.e. a thermosetting resin, may be further provided between the outer surface of the battery cell <NUM> and the partition wall <NUM>.

Although the adhesive member <NUM> is shown as being interposed only between the partition wall <NUM> and the side surface of the battery cell <NUM> in <FIG>, it is obvious that the adhesive member may also be formed between the lower plate <NUM> and the bottom surface of the battery cell <NUM>.

Although not particularly restricted, the thickness of the partition wall <NUM> or the sum of the thickness of the partition wall <NUM> and the thickness of the adhesive member <NUM> may be <NUM> or less, preferably <NUM> or less, in order to increase energy density of the battery module.

<FIG> is a flowchart illustrating a battery 4module manufacturing method according to a preferred embodiment of the present invention, and <FIG> is a conceptual view illustrating the battery module manufacturing method according to the preferred embodiment of the present invention.

Referring to <FIG> and <FIG>, the battery module manufacturing method according to the preferred embodiment of the present invention includes a step (S1) of preparing a module case having a plurality of receiving portions formed therein, a step (S2) of injecting an adhesive member into the plurality of receiving portions, a step (S3) of receiving a battery cell in each of the receiving portions, and a step (S4) of performing heating to a predetermined temperature to fix the battery cell.

First, the step (S1) of preparing the module case having the plurality of receiving portions formed therein is a step of preparing a module case <NUM> having the above construction, i.e. a module case <NUM> having a space defined by a lower plate <NUM> and four side plates <NUM>, wherein receiving portions <NUM> are formed in the space by partition walls <NUM>, each of which includes a lower partition wall <NUM>(a) and an upper partition wall <NUM>(b).

Here, it is obvious that the inner diameter of each of the receiving portions <NUM> must be slightly greater than the outer diameter of a cylindrical battery cell received therein, and glass bubbles are preferably mixed in the upper partition wall <NUM>(b).

Meanwhile, it is preferable for the module case <NUM> to be manufactured as one body by injection molding. As an example, over-molding, multiple injection, or blocking injection molding may be used. However, the molding method is not particularly restricted as long as it is possible to integrate dissimilar materials. In the case in which the above molding method is adopted, there are advantages in that it is possible to form a partition wall <NUM> having a small thickness and the thickness of the partition wall <NUM> is uniform.

The step (S2) of injecting the adhesive member into the plurality of receiving portions is a step of injecting a predetermined amount of an adhesive member <NUM> made of a thermosetting material, such as silicon, epoxy, or polyurethane, through an injection portion <NUM>.

The adhesive member <NUM> fills a gap between a battery cell <NUM> to be received and the partition wall <NUM> in order to securely fix the battery cell <NUM> and to prevent heat transfer to another battery cell <NUM> adjacent thereto.

In the step (S3) of receiving the battery cell in each of the receiving portions, the battery cell <NUM> is seated in the receiving portion <NUM> in the state in which the receiving portion <NUM> is filled with the predetermined amount of the adhesive member <NUM>. At this time, the adhesive member <NUM> is pushed upwards to the space between the partition wall <NUM> and the battery cell <NUM>, whereby the adhesive member has a shape surrounding the outer circumferential surface of the battery cell <NUM>.

The step (S4) of performing heating to a predetermined temperature to fix the battery cell, which is the last step, is a step of heating the adhesive member <NUM> to a predetermined temperature at which a thermosetting resin can be hardened for a predetermined time to fix the battery cell <NUM> to the partition wall <NUM>.

Conventionally, a plurality of battery cells is received in a module case, a thermosetting resin is injected into a space between the battery cells, and the thermosetting resin is hardened, whereby a battery module is manufactured. However, it is not easily to inject the thermosetting resin into a small gap between the battery cells, whereby product defects are incurred and manufacturing time is increased.

In the present invention, by contrast, a module case having battery cell receiving portions formed therein is prepared, an adhesive member is injected into the receiving portions, and battery cells are received and hardened, whereby it is possible to very easily form a partition wall that partitions the battery cells.

The present invention may provide a battery pack having received therein a battery module manufactured by the battery module manufacturing method having at least one of the features described above.

Claim 1:
A method of manufacturing a battery module capable of preventing chain ignition, the method comprising:
preparing a module case (<NUM>) having a plurality of receiving portions (<NUM>) formed therein, each of the plurality of receiving portions (<NUM>) having a space of a predetermined size;
receiving a battery cell (<NUM>) in each of the plurality of receiving portions (<NUM>); and
performing heating to a predetermined temperature to fix the battery cell (<NUM>),
wherein the module case (<NUM>) comprises a lower plate (<NUM>), a plurality of side plates (<NUM>), and a plurality of partition walls (<NUM>) configured to form the plurality of receiving portions (<NUM>), and
wherein each of the partition walls (<NUM>) comprises a lower partition wall (<NUM>(a)) extending from the lower plate (<NUM>) by a predetermined height and an upper partition wall (<NUM>(b)) extending from the lower partition wall (<NUM>(a)) by a predetermined height,
wherein the lower partition wall (<NUM> (a)) and the upper partition wall (<NUM>(b)) are made of different materials,
characterized in that each of the lower plate (<NUM>), the side plates (<NUM>), and the lower partition walls (<NUM>(a)) of the module case (<NUM>) is made of a thermoplastic resin, and
wherein the upper partition walls (<NUM>(b)) are made of a thermosetting resin.