Battery packs and devices containing them

Abstract

A battery pack according to one embodiment of the present invention includes one or more first battery modules including a plurality of battery cells, and one or more second battery modules arranged adjacent to each of the first battery modules and including a plurality of battery cells, wherein the first battery module and the second battery module have different maximum states of charge (SOC).

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0144751, dated November 2, 2022, and all contents disclosed in the documents of that patent application are incorporated herein by reference.

[0002] The present invention relates to a battery pack and a device including the same, and more particularly to a battery pack with improved safety and a device including the same. [Background technology]

[0003] In modern society, the use of portable devices such as mobile phones, laptops, video cameras, and digital cameras has become commonplace, and technological development in fields related to these mobile devices is accelerating. Furthermore, rechargeable secondary batteries are being used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), and other vehicles as a way to address air pollution caused by conventional gasoline-powered vehicles that use fossil fuels, and this has led to an increased need for the development of secondary batteries.

[0004] Currently, commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Of these, lithium secondary batteries are attracting attention due to their advantages over nickel-based secondary batteries, such as almost no memory effect, freedom in charging and discharging, extremely low self-discharge rate, and high energy density.

[0005] Such lithium secondary batteries mainly use lithium-based oxides and carbon materials as positive and negative electrode active materials, respectively, and include an electrode assembly in which positive and negative electrode plates coated with the positive and negative electrode active materials are arranged with a separator sandwiched therebetween, and a battery case that hermetically houses the electrode assembly together with an electrolyte.

[0006] Generally, lithium secondary batteries can be classified into can-type secondary batteries, in which an electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which an electrode assembly is housed in a pouch made of an aluminum laminate sheet, depending on the shape of the exterior material.

[0007] Secondary batteries used in small devices are configured with two or three battery cells, while secondary batteries used in medium- to large-sized devices such as automobiles use battery modules in which multiple battery cells are electrically connected. These battery modules improve capacity and output by connecting multiple battery cells in series or parallel to form a stack of battery cells. One or more battery modules can also be installed with various control and protection systems, such as a battery disconnect unit (BDU), battery management system (BMS), and cooling system, to form a battery pack.

[0008] When a battery pack is constructed by connecting a plurality of battery cells in series or parallel, a battery module consisting of at least one battery cell is generally constructed first, and other components are added to the battery pack using the at least one battery module. The number of battery modules included in the battery pack or the number of battery cells included in a battery module can be variously set according to the required output voltage or charge / discharge capacity.

[0009] Recently, with the development of high-capacity cells, the safety of secondary batteries, especially thermal propagation characteristics, has become important. As the cell capacity increases, the thermal propagation safety decreases, so it is necessary to improve this. Summary of the Invention [Problem to be solved by the invention]

[0010] The problem to be solved by the present invention is to provide a battery pack and a device including the same that have enhanced safety while using existing high-capacity cells.

[0011] However, the problems to be solved by the embodiments of the present invention are not limited to the above problems, and can be variously expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0012] A battery pack according to one embodiment of the present invention includes one or more first battery modules including a plurality of battery cells, and one or more second battery modules arranged adjacent to each of the first battery modules and including a plurality of battery cells, wherein the first battery module and the second battery module have different maximum states of charge (SOC).

[0013] The one or more first battery modules may have a maximum charging rate of 100%, and the one or more second battery modules may have a maximum charging rate of 90%.

[0014] The battery pack may further include a controller connected to the one or more first battery modules and the one or more second battery modules, for controlling charging and charging rate.

[0015] The control unit may control the one or more first battery modules to have a charging rate of 100% and the one or more second battery modules to have a charging rate of 90% when the charging is performed.

[0016] Any one of the one or more first battery modules may be arranged to be surrounded by the one or more second battery modules.

[0017] Any one of the one or more second battery modules may be arranged to be surrounded by the one or more first battery modules.

[0018] The one or more first battery modules and the one or more second battery modules may be arranged alternately.

[0019] The battery cells included in the first battery module and the second battery module may be of the same type.

[0020] The battery pack may further include a pack frame that packages the one or more first battery modules and the one or more second battery modules.

[0021] A device according to another embodiment of the present invention may include the at least one battery pack. [Effects of the Invention]

[0022] According to an embodiment of the present invention, it is possible to provide a battery pack and a device including the same that have enhanced safety while using existing high-capacity cells.

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

[0024] [Figure 1] 1 is an exploded perspective view of a battery module included in a battery pack according to an embodiment of the present invention; [Figure 2] 1 is a diagram showing a battery pack according to an embodiment of the present invention. [Figure 3] 3 is a diagram showing a schematic diagram of the battery pack of FIG. 2, including a control unit and a charging unit. DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention will now be described in detail with reference to the accompanying drawings, in which various embodiments of the present invention can be easily implemented by those skilled in the art. The present invention can be implemented in several different forms and is not limited to the examples described herein.

[0026] In order to clearly describe the present invention, parts that are not relevant to the description will be omitted and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0027] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. In the drawings, thicknesses are exaggerated to clearly show multiple layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for the convenience of explanation.

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

[0029] Furthermore, throughout the specification, when a part "comprises" a certain element, it does not mean that it excludes other elements, but that it may further include other elements, unless otherwise specified.

[0030] Also, throughout the specification, "on a plane" means when the target part is viewed from above, and "on a cross section" means when the target part is cut vertically and viewed from the side.

[0031] The battery pack of the present invention will be described below with reference to FIGS.

[0032] FIG. 1 is an exploded perspective view of a battery module included in a battery pack according to an embodiment of the present invention, FIG. 2 is a view showing a battery pack according to an embodiment of the present invention, and FIG. 3 is a view showing the battery pack of FIG. 2, including a control unit and a charging unit.

[0033] Referring to FIG. 1, each of the first and second battery modules 100, 200 included in a battery pack according to an embodiment of the present invention includes a battery cell assembly 400 including one or more battery cells, a module frame 210 that houses the battery cell assembly 400, and end plates 300 that are located at both ends of the battery cell assembly 400 in the longitudinal direction and that are coupled to openings in the module frame 210.

[0034] The battery cell assembly 400 is a secondary battery assembly including a plurality of battery cells 112. The battery cell assembly 400 may include a plurality of battery cells 112, each of which includes an electrode lead 114. The battery cells 112 may be, but are not limited to, pouch-type battery cells having a plate shape. The electrode lead 114 is a positive or negative lead, and the end of the electrode lead 114 of each battery cell 112 may be bent in one direction so as to abut against the end of the electrode lead of another adjacent battery cell 112. Two electrode leads 114 that are in contact with each other may be fixed to each other by welding or the like, thereby establishing an electrical connection between the battery cells 112 inside the battery cell assembly 400.

[0035] In addition, a bus bar frame 500 may be provided that is housed in the module frame 210 together with the battery cell assemblies 400. The bus bar frame 500 may include an upper frame 510 located on top of the cell assemblies 400, a front frame 520 located on the front surface of the battery cell assemblies 400, and a rear frame 530 located on the rear surface of the battery cell assemblies 400, and bus bars 540 connected to the electrode leads 114 of the battery cells that make up the battery cell assemblies 400 may be mounted on the front frame 520 and the rear frame 530.

[0036] A plurality of battery cells 112 are stacked vertically with their electrode leads 114 aligned in one direction to form a battery cell assembly 400. The battery cell assembly 400 is housed in a module frame 120 having at least one opening extending in the lengthwise direction of the battery cell assembly 400. The electrode leads 114 are extended to the outside of the module frame 210 through the opening, and the extended electrode leads 114 are coupled to the front frame 520 and rear frame 530 of the bus bar frame 500, respectively, and can be electrically connected to the bus bars 540 mounted thereon. The bus bar frame 500 can be made of an insulating material, for example, a non-conductive synthetic resin, and the bus bars 540 can be made of a conductive metal material.

[0037] Each of the first and second battery modules 100, 200 may include a flexible printed circuit board (FPCB) (not shown) that is attached to the module frame 210 and extends in the longitudinal direction from the top of the battery cell assembly 400 and is configured to sense the battery cells 112. Furthermore, the first and second battery modules 100, 200 may include various electrical components, such as an internal circuit board (ICB) and a BMS. The electrical components, such as the ICB and BMS board, may be electrically connected to the plurality of battery cells 112.

[0038] Each of the first and second battery modules 100, 200 may further include a thermally conductive resin layer 700 positioned between the lower surface of the battery cell assembly 400 and the module frame 210. The thermally conductive resin layer 700 is formed by injecting a thermally conductive resin and serves to transfer heat generated from the battery cell assembly 400 to the bottom surfaces of the first and second battery modules 100, 200, as well as to fix the cell assembly 400 within the first and second battery modules 100, 200.

[0039] Meanwhile, a heat sink 800 may be provided on the side of the battery cell assembly 400 and may be housed together in the module frame 210, but this is not particularly limited.

[0040] The configurations of the first and second battery modules 100, 200 have been described above, but the shapes and configurations are not limited to these, and the shapes and configurations can be changed in some cases.

[0041] Next, a battery pack 10 according to an embodiment of the present invention will be described with reference to FIGS.

[0042] The battery pack 10 includes one or more first battery modules 100, one or more second battery modules 200, and a pack frame 11 that houses them.

[0043] The first and second battery modules 100, 200 have different maximum states of charge (SOC). Here, the SOC is the ratio of remaining capacity to maximum capacity and is usually expressed in the range of 0 to 100%. The remaining capacity indicates the amount of charge currently stored in the battery pack. In this embodiment, the first and second battery modules 100, 200 are characterized in that, in controlling the SOC, their maximum charged states are controlled differently. Preferably, the maximum SOC of the first battery module 100 is 100%, and the maximum SOC of the second battery module 200 is 90%.

[0044] The first and second battery modules 100, 200 having different maximum charging rates may be arranged alternately as shown in Fig. 2. That is, the second battery modules 200 may be arranged on all four sides of one first battery module 100, and the first battery modules 100 may be arranged on all four sides of one second battery module 200.

[0045] In a battery pack including the first and second battery modules 100, 200 arranged in this manner, the second battery module exhibits a lower explosion pressure when a battery cell ignites, thereby improving heat transfer safety. In other words, a second battery module 200 with a 90% SOC exhibits an explosion pressure (pressure exerted when a battery cell ignites) that is approximately 40% lower than a first battery module with a 100% SOC. Therefore, when the second battery module 200 and the first battery module 100 are alternately arranged and heat is applied, the ignition time and explosion pressure are measured. The ignition time is increased and the explosion pressure is reduced compared to when only modules with a 100% SOC are arranged together. Furthermore, even if a first battery module 100 ignites, the adjacent second battery module 200 exhibits a lower explosion pressure due to its lower SOC. Therefore, when a second battery module 200 ignites, its own explosion pressure is lower, thereby reducing the impact on the adjacent first battery module 100.

[0046] On the other hand, if the maximum charge rate of the second battery module 200 is higher than 90%, it is difficult to achieve the above-mentioned effect of reducing the explosive pressure, and if it is less than 90%, the high output required by the device cannot be achieved, so it is preferable to control it to the 90% level.

[0047] Furthermore, in the case of the first and second battery modules 100, 200, in order to adjust the output, the above-mentioned effects can be obtained by changing only the state of charge (SOC) without changing the type or structure of the battery cells 112 contained in each battery module, with the battery module configuration generally including the same type of battery cells 112.

[0048] For state of charge (SOC) control, the battery pack 10 of this embodiment may include a control unit 610 connected to the plurality of first battery modules 100 and the plurality of second battery modules 200. The control unit 610 is also connected to a charging unit 620, and can monitor the state of charge (SOC) during charging of the first and second battery modules 100, 200 and control the maximum state of charge to be limited to 100% and 90%, respectively.

[0049] Such monitoring and control can be achieved by estimating and controlling the SOC using one or a combination of two or more of various well-known techniques. As described above, according to the battery pack 10 according to the embodiment of the present invention, by arranging a plurality of battery modules having different maximum charging rates, it is possible to improve the heat propagation characteristics when a battery cell included in a battery module ignites, that is, to extend the ignition time and reduce the explosion pressure.

[0050] The battery pack described above can be applied to various devices, including transportation means such as electric bicycles, electric cars, and hybrid cars, but the present invention is not limited thereto and can be applied to various devices that can use a battery module and a battery pack including the same, which also fall within the scope of the present invention.

[0051] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0052] 10 Battery pack 11 Pack Frame 100 first battery module 112 battery cells 114 Electrode Lead 120 module frame 200 Second battery module 210 Module Frame 300 End Plate 400 Battery Cell Assembly 400 Cell Assembly 500 Busbar Frame 510 Upper Frame 520 Front Frame 530 rear frame 540 Busbar 610 Control Unit 620 Live parts 700 Thermally conductive resin layer 800 Heat sink

Claims

1. one or more first battery modules including a plurality of battery cells; one or more second battery modules disposed adjacent to each of the first battery modules and including a plurality of battery cells; The first battery module and the second battery module are battery packs having different maximum states of charge (SOC).

2. The battery pack of claim 1 , wherein the one or more first battery modules have a maximum charging rate of 100%, and the one or more second battery modules have a maximum charging rate of 90%.

3. The battery pack according to claim 1 or 2, further comprising a controller connected to the one or more first battery modules and the one or more second battery modules, for controlling charging and charging rate.

4. 4. The battery pack of claim 3, wherein the control unit controls the one or more first battery modules to have a charging rate of 100% and the one or more second battery modules to have a charging rate of 90% when the charging is performed.

5. The battery pack according to claim 1 or 2, wherein any one of the one or more first battery modules is arranged to be surrounded by the one or more second battery modules.

6. The battery pack according to claim 1 or 2, wherein any one of the one or more second battery modules can be arranged to be surrounded by the one or more first battery modules.

7. The battery pack according to claim 1 or 2, wherein the one or more first battery modules and the one or more second battery modules are arranged alternately.

8. The battery pack according to claim 1 or 2, wherein the battery cells included in the first battery module and the second battery module are of the same type.

9. The battery pack according to claim 1 or 2, further comprising a pack frame that packages the one or more first battery modules and the one or more second battery modules.

10. A device comprising at least one battery pack according to claim 1 or 2.

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