Battery module and battery pack including the same

Abstract

A battery module according to an embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked, a module case that houses the battery cell stack, a film heater formed between the module case and the outermost battery cell of the battery cell stack, and a dummy battery cell disposed between the film heater and the outermost battery cell.

Description

Technical Field

[0001] Cross-reference to Related Applications This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0180416 filed on December 21, 2022, and all the contents disclosed in the literature of the patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module and a battery pack including the same, and more particularly, to a battery module that reduces environmental deviation between battery cells and a battery pack including the same.

Background Art

[0003] Secondary batteries have attracted much attention as an energy source in various product groups such as mobile devices and electric vehicles. Such secondary batteries are a powerful energy resource that can replace the use of existing products using fossil fuels, and are in the spotlight as an environmentally friendly energy source that does not generate by-products due to energy use.

[0004] Recently, as the need for large-capacity secondary battery structures, including the use of secondary batteries as an energy storage source, has increased, the demand for battery packs with a multi-module structure that combines a number of battery modules in which a large number of secondary batteries are connected in series / parallel has been increasing.

[0005] On the other hand, when a battery pack is configured by connecting a plurality of battery cells in series / parallel, it is common to configure a battery module including at least one battery cell and add other components using such at least one battery module to configure a battery pack.

[0006] Such a battery module includes a battery cell stack in which a plurality of battery cells are stacked, a module case that houses the battery cell stack, and a compression pad formed between the module case and the outermost battery cell of the battery cell stack or between a plurality of battery cells.

[0007] FIG. 1 is a diagram showing a conventional battery module. FIG. 2 is a diagram showing a cross-section of the battery module of FIG. 1.

[0008] In the conventional battery module 1, the outermost battery cell of the battery cell stack in which a plurality of battery cells 11 are stacked is positioned in direct contact with the module case 20. At this time, as the number of battery cells 11 constituting the battery module 1 increases, performance deviations occur in each of the battery cells 11 arranged in the battery module 1, and ultimately, it can only affect the performance of the battery pack formed by connecting the battery modules in parallel or in series.

[0009] Since the battery cell 11 is a heat-generating body, the temperature rises when tests such as output, rapid charging, and lifespan are performed. However, the battery cell located on the outermost side in the battery module 1 is in contact with the module case 20 of the battery module whose one side is not a cell, so the effect of temperature is smaller than that of the battery cell located in the center, and the performance of the battery cell decreases. As a result, the performance of the battery module 1 is determined by the outermost cell. This may cause a general decrease in the performance of the battery module. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] The problem to be solved by the present invention is to provide a battery module and a battery pack including the same that minimize performance and temperature deviations between battery cells due to position inside the battery module.

[0011] The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned should be clearly understood by those skilled in the art from the following description. MEANS FOR SOLVING THE PROBLEMS

[0012] A battery module according to an embodiment of the present invention for realizing the above object includes a battery cell stack in which a plurality of battery cells are stacked, a module case that houses the battery cell stack, a film heater formed between the module case and the outermost battery cell of the battery cell stack, and a dummy battery cell disposed between the film heater and the outermost battery cell.

[0013] The dummy battery cell has the same configuration as the plurality of battery cells and may not be electrically connected to the plurality of battery cells.

[0014] The dummy battery cell may not be charged or discharged.

[0015] The battery module may further include a first temperature sensor attached to the dummy battery cell.

[0016] The battery module may further include a second temperature sensor attached to the innermost battery cell among the plurality of battery cells.

[0017] The battery module may further include a control unit that controls the first temperature measured by the first temperature sensor and the second temperature measured by the second temperature sensor to be maintained the same.

[0018] The control unit may be connected to the film heater and heat the film heater based on the results of monitoring the first temperature and the second temperature.

[0019] The pressures received by each of the plurality of battery cells may all be the same.

[0020] The film heater can be formed of at least one of carbon, a copper foil bus bar, a silver foil bus bar, a base PET film, and a laminax film, which are heating elements.

[0021] A battery pack according to another embodiment of the present invention can include at least one or more of the aforementioned battery modules.

Advantages of the Invention

[0022] A battery module according to an embodiment of the present invention and a battery pack including the same arrange dummy battery cells that do not participate in charge and discharge at the position of the outermost battery cells having a relatively low temperature in the battery cells, and at the same time arrange a film heater on the dummy battery cells and use a temperature sensor to maintain the same temperature between the dummy battery cells and the central battery cells, thereby maintaining the temperature and pressure of the battery cells uniformly, and thereby minimizing the performance and life deviation between the battery cells.

[0023] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned should be clearly understood by those skilled in the art from the description of the claims.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0025] Hereinafter, with reference to the attached drawings, various embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement it. The present invention can be realized in various different forms and is not limited to the embodiments described herein.

[0026] In order to clearly explain the present invention, parts unnecessary for the explanation are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

[0027] Also, the sizes and thicknesses of the respective configurations shown in the drawings are arbitrarily shown for convenience of explanation, and thus the present invention is not necessarily limited to the places shown in the drawings. The thicknesses are enlarged in the drawings to clearly represent various layers and regions. And, in the drawings, for convenience of explanation, the thicknesses of some layers and regions are exaggerated.

[0028] Also, when a part such as a layer, film, region, plate, etc. is "on" or "above" another part, this includes not only the case where it is "directly above" the other part but also the case where there are other parts in between. Conversely, when a part is "directly above" another part, it means that there are no other parts in between. Also, being "on" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" or "above" in the direction opposite to gravity.

[0029] Also, throughout the specification, when a part "includes" a certain component, this means that other components can be further included, rather than excluding other components unless otherwise stated to the contrary.

[0030] Hereinafter, a battery module according to an embodiment of the present invention will be described with reference to FIGS. 3 to 6.

[0031] FIG. 3 is a diagram showing a battery module according to an embodiment of the present invention, FIG. 4 is a diagram showing a disassembled state of the battery module of FIG. 3, FIG. 5 is a diagram showing a cross-section cut along A-A' of FIG. 3, and FIG. 6 is a conceptual diagram showing a configuration connected to a control unit in the battery module according to an embodiment of the present invention.

[0032] Referring to FIGS. 3 to 6, a battery module 10 according to an embodiment of the present invention includes a battery cell stack 100 in which battery cells 110 are stacked, a module case 200 that houses the battery cell stack 100, dummy battery cells 111 formed between the module case 200 and the outermost battery cell, and a film heater 300 formed between the module case 200 and the dummy battery cells 111.

[0033] The battery cell 110 is a secondary battery and can be composed of a pouch-type secondary battery. A plurality of such battery cells 110 can be provided, and the plurality of battery cells 110 can be mutually stacked so as to be electrically connected to each other to form a battery cell stack. Each of such a plurality of battery cells can include an electrode assembly, a case that houses the electrode assembly, and an electrode lead protruding from the electrode assembly. The electrode assembly can be composed of a positive electrode plate, a negative electrode plate, a separator, and the like. The case houses the electrode assembly and can be made of a laminate sheet including a resin layer and a metal layer. The electrode lead is formed to protrude from the case and is electrically connected to the electrode assembly. Such an electrode lead may be provided at both ends of the battery cell 110. The battery cell according to an embodiment of the present invention has a structure in which two electrode leads protrude from both ends of the battery cell 110 facing each other.

[0034] According to an embodiment of the present invention, the module case 200 is formed from the top, bottom, left, and right sides so as to accommodate the battery cell stack 100. However, the module case 200 may be formed from a U-shaped module case and an upper plate that covers the open upper part of the U-shaped module case, or conversely, may be formed from an inverted U-shaped module case and a lower plate that covers the lower part. Through such a module case 200, the battery cell 110 and the components connected to the battery cell 110 can be protected from external physical impacts.

[0035] The dummy battery cell 111 is formed between the module case 200 and the outermost battery cell 110 of the battery cell stack 100. The dummy battery cell 111 is configured identically to the battery cell 110, but is a cell that is disposed at both ends of the battery cell stack 100 and is not electrically connected and does not participate in charge and discharge. Thereby, it can function to absorb the pressure generated when the swelling phenomenon of the battery cell 110 occurs. Also, by providing, as dummy battery cells 111 that do not participate in charge and discharge, the battery cells located on the outermost side and at the center, which have a large temperature and pressure deviation and conventionally reduced the performance of the entire battery module 10 due to performance reduction, even if the temperature and pressure deviation of the dummy battery cells 111 becomes large, it is possible to prevent it from affecting the performance of the entire battery module 10. Also, since all the battery cells 110 that are electrically connected and charged and discharged are all adjacent to other battery cells 110 or dummy battery cells 111 themselves, they can receive the same pressure. That is, conventionally, one surface of the battery cell 110 located on the outermost periphery always contacts another external component (such as the module case 200), so it is placed in an environment different from other inner battery cells 110 and a difference occurs in the pressure received. However, in the case of this embodiment, by including the dummy battery cells 111 as described above, the pressure received by all the battery cells 110 can be made the same.

[0036] The film heater 300 is formed between the module case 200 and the dummy battery cell 111 of the battery cell laminate 100. Thereby, the temperature of the dummy battery cell 111 adjacent to the film heater 300 can be increased. The film heater 300 can be formed from carbon, a copper foil bus bar, a silver foil bus bar, a base PET film, which are heating elements, and a laminax film. Such a film structure may be used when performing construction for improving heating efficiency.

[0037] Also, as shown in FIG. 5, in the battery module 10, in order to minimize the performance deviation of the battery cell 110 due to position, a first temperature sensor 410 is attached to the dummy battery cell 111, and a second temperature sensor 420 is attached to the battery cell 110 located at the center. By monitoring the temperatures of the battery cell 110 and the dummy battery cell 111 through these, the temperature deviation between the battery cells of the battery cell laminate 100 can be minimized. That is, as shown in FIG. 6, the first temperature sensor 410 and the second temperature sensor 420 are connected to the control unit 500, and the first temperature measured by the first temperature sensor 410 and the second temperature measured by the second temperature sensor 420 are summarized by the control unit 500. When the temperature of the dummy battery cell 111 is low based on the measured temperature, the film heater 300 can be controlled to be heated to eliminate the temperature deviation between the battery cell 110 and the dummy battery cell 111.

[0038] When monitoring and controlling the temperature of the dummy battery cell 111 arranged outside and the temperature of the battery cell 110 at the center to be the same, the temperature of the battery cell 110 arranged between the dummy battery cell 111 and the battery cell 110 at the center can also be maintained uniformly. Also, since the pressure received by the battery cell 110 is absorbed by the dummy battery cell 111, the pressure received by the battery cell 110 that is not the dummy battery cell 111 can also be maintained uniformly regardless of its position within the battery module 10. In this way, by making the temperature and pressure the same for the battery cell 110 regardless of its position within the battery module 10, the cell characteristics and degradation rate of the battery cell 110 can be made the same. Therefore, by reducing the deviation in characteristics and degradation rate between the battery cells 110, it becomes possible to prevent problems from occurring in some of the battery cells 110, particularly the battery cells 110 arranged outside, and degrading the performance of the entire battery module 10.

[0039] On the other hand, in this embodiment, it was shown that the film heater 300 corresponds to the entire area of the dummy battery cell 111. However, it is not limited to this, and it is also possible to reduce its size within a range that does not overlap with the electrode leads. At this time, the position of the film heater 300 is preferably close to the center of the dummy battery cell 111. Also, in this embodiment, it was exemplified that the film heater 300 is arranged only on the dummy battery cell 111. However, it is not limited to this, and it can also be arranged between the battery cells 110 arranged inside and controlled to locally increase the temperature of the battery cell 110 as needed. Also, the temperature sensors 410 and 420 are not particularly limited as long as they are at appropriate positions and sizes for specifying the temperature of the battery cell 110 and can be adjusted appropriately.

[0040] The aforementioned battery module 10 may be included in a battery pack. The battery pack may have a structure in which one or more battery modules according to this embodiment are assembled, and a battery management system (Battery Management System; BMS) for managing the temperature, voltage, etc. of the battery and a cooling device are added and packed.

[0041] The battery pack can be applied to various devices. Such devices can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto and is applicable to various devices that can use battery modules, which also belong to the scope of the rights of the present invention.

[0042] The preferred embodiments of the present invention have been illustrated and described above. However, the present invention is not limited to the specific embodiments described above, and various modifications can be made by those with ordinary knowledge in the technical field to which the present invention pertains without departing from the gist of the present invention claimed in the claims. Of course, such modifications should not be individually understood from the technical idea and perspective of the present invention.

Explanation of Reference Numerals

[0043] 100: Battery cell stack 110: Battery cell 111:Dummy battery cell 200: Module case 300: Film heater 410: First temperature sensor 420: Second temperature sensor

Claims

1. A battery cell stack in which a plurality of battery cells are stacked; A module case that houses the battery cell stack; A film heater formed between the module case and the outermost battery cell of the battery cell stack, and A dummy battery cell disposed between the film heater and the outermost battery cell A battery module including.

2. The battery module according to claim 1, wherein the dummy battery cell has the same configuration as the plurality of battery cells and is not electrically connected to the plurality of battery cells.

3. The battery module according to claim 2, wherein the dummy battery cell is not charged or discharged.

4. The battery module according to any one of claims 1 to 3, further including a first temperature sensor attached to the dummy battery cell.

5. The battery module according to claim 4, further including a second temperature sensor attached to the innermost battery cell among the plurality of battery cells.

6. The battery module according to claim 5, further including a control unit that controls so that a first temperature measured by the first temperature sensor and a second temperature measured by the second temperature sensor are maintained the same.

7. The battery module according to claim 6, wherein the control unit is connected to the film heater and heats the film heater based on a result of monitoring the first temperature and the second temperature.

8. The battery module according to claim 1, wherein pressures received by each of the plurality of battery cells are all the same.

9. The battery module according to claim 1, wherein the film heater is formed of at least one of carbon, a copper foil bus bar, a silver foil bus bar, a base PET film, and a laminax film, which are heating elements.

10. A battery pack including the battery module according to claim 1.

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