Battery pack

Abstract

The present disclosure relates to a battery pack. The technical problem is to be solved by providing a battery pack comprising: a case; a plurality of all-solid-state battery cells accommodated in the case; and a plurality of disk springs arranged between the plurality of all-solid-state battery cells, wherein the plurality of disk springs are arranged in the direction perpendicular to an interface between a negative electrode, a solid electrolyte and a positive electrode inside the plurality of all-solid-state battery cells, so as to press the interface.

Description

battery pack

[0001] The present disclosure relates to a battery pack including an all-solid-state battery cell.

[0002] Recent industrial demands have led to the active development of batteries with high energy density and safety. For example, lithium-ion batteries are being used not only in information and communication devices, but also in the automotive sector. Safety is particularly important in the automotive sector, as it is directly related to life.

[0003] Lithium-ion batteries currently on the market use electrolytes containing flammable organic solvents, which poses a risk of overheating and fire in the event of a short circuit. To address this issue, all-solid-state secondary batteries using solid electrolytes are being proposed.

[0004] All-solid-state secondary batteries do not use flammable organic solvents, significantly reducing the risk of fire or explosion even in the event of a short circuit. Therefore, these all-solid-state secondary batteries significantly improve safety compared to lithium-ion batteries that use electrolytes. Furthermore, all-solid-state secondary batteries can achieve high energy densities.

[0005] In addition, one of the characteristics of all-solid-state secondary batteries is that there is no need for a liquid electrolyte injection process, so all components can be stacked layer by layer.

[0006] Typically, to overcome interfacial resistance at each layer, various separate pressurization processes are employed, including uniaxial pressurization, roll presses using tip-up pressurization, CIP, and WIP. However, these pressurization processes pose challenges such as high process equipment costs and production index time loss, necessitating the introduction of new alternatives to interfacial pressurization.

[0007] The problem to be solved by the present invention is to provide a battery pack having structural safety without requiring a separate pressurizing process for forming an interface of an all-solid-state battery cell.

[0008] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0009] According to one embodiment of the present invention for solving the above technical problem, a battery pack comprises: a case; a plurality of all-solid-state battery cells accommodated in the case; and a plurality of disk springs arranged between the plurality of all-solid-state battery cells, wherein the plurality of disk springs are arranged in a direction perpendicular to an interface between a negative electrode, a solid electrolyte, and a positive electrode inside the plurality of all-solid-state battery cells, thereby pressurizing the interface.

[0010] The case may include a disc spring coupling that is accommodated in the case and fixes the plurality of disc springs.

[0011] The disc spring coupling part further includes a first coupling part that is arranged on each of both sides of the disc spring coupling part and fixes the side of the disc spring, and the disc spring can be fixed on both sides to the side of the disc spring coupling part by the first coupling part.

[0012] The above first coupling portion may be positioned at the center portion of the disk spring coupling portion.

[0013] It further includes a second coupling portion arranged on the busbar holder and fixing the upper portion of the disc spring, wherein the upper portion of the disc spring can be fixed to the busbar holder by the second coupling portion.

[0014] The case further includes a third connecting portion arranged on the lower surface and fixing the lower portion of the disc spring, wherein the lower portion of the disc spring can be fixed to the lower surface of the case by the third connecting portion.

[0015] A busbar holder is arranged on the upper side of the above-mentioned disk spring joint, and a busbar can be arranged on the upper side of the busbar holder.

[0016] A terminal portion is arranged on the upper side of the plurality of all-solid-state battery cells, and the terminal portion can be connected to the bus bar by penetrating the bus bar holder hole of the bus bar holder.

[0017] A hook portion is arranged on the lower side of the above bus bar holder, and the hook portion can be inserted and connected to a hook portion insertion portion formed at a corner of the case.

[0018] The above hook portion and the above hook portion insertion portion can be positioned at corresponding positions on the four corners of the case.

[0019] The above disc spring may be insulated coated.

[0020] The positive electrode has a positive current collector and a positive active material layer laminated, the negative electrode has a negative current collector and a negative active material layer laminated, and the disk spring is arranged in a direction perpendicular to the interface between the positive current collector, the positive active material layer, the negative current collector, the negative active material layer, and the solid electrolyte, and can pressurize the interface.

[0021] Other aspects, features and advantages other than those described above will become apparent from the following detailed description, claims and drawings for carrying out the invention.

[0022] A battery pack according to one embodiment of the present invention comprises a disk spring disposed between a plurality of all-solid-state battery cells, such that the disk spring maintains overall pressure between the plurality of all-solid-state battery cells and a case, thereby enabling interface activation of the plurality of all-solid-state battery cells accommodated in the battery pack.

[0023] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects that are not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0024] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0025] FIG. 1 is an exploded perspective view of a battery pack according to one embodiment of the present invention;

[0026] FIG. 2 is an exploded perspective view showing a plurality of all-solid-state battery cells of the battery pack of FIG. 1 and a disk spring between the plurality of all-solid-state battery cells;

[0027] Fig. 3 illustrates a cross-sectional view taken along line DD' of Fig. 2;

[0028] Fig. 4 is a perspective view of a disc spring joint;

[0029] FIG. 5 is a cross-section taken along line AA' of FIG. 1, showing a case and a disk spring mounted on the case;

[0030] Fig. 6 shows a case of Fig. 5 in which a plurality of all-solid-state battery cells are accommodated;

[0031] Fig. 7 illustrates a cross-section of BB' in Fig. 1;

[0032] Fig. 8 illustrates a cross-section CC' of Fig. 1;

[0033] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms or words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, but should be interpreted with meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term in order to explain his own invention in the best way. Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical idea of ​​the present invention, and various equivalents and modifications may exist at the time of filing this application. In addition, when used in this specification, "comprise" and "include" and / or "comprising" specify the presence of mentioned shapes, numbers, steps, operations, elements, components and / or groups thereof, and do not exclude the presence or addition of one or more other shapes, numbers, operations, elements, components and / or groups. Additionally, when describing embodiments of the present invention, the phrases “may” and “may be” may include “one or more embodiments of the present invention.”

[0034] Additionally, to facilitate understanding of the invention, the attached drawings are not drawn to scale and some components may be exaggerated in size. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0035] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given region may imply uniformity on average.

[0036] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0037] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0038] Any configuration being placed "on (or under)" or "above (or below)" a component may mean not only that any configuration is placed in contact with the upper surface (or lower surface) of said component, but also that other configurations may intervene between said component and any configuration placed on (or below) said component.

[0039] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to each other, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component. Furthermore, when it is said that a part is electrically coupled to another part, this includes not only cases where they are directly connected, but also cases where they are connected with another element in between.

[0040] When reference is made throughout the specification to "A and / or B," this means A, B, or A and B, unless otherwise stated. In other words, "and / or" includes all or any combination of the listed items. When reference is made to "C through D," this means C or more and D or less, unless otherwise stated.

[0041] Hereinafter, a battery pack according to one embodiment of the present invention will be described with reference to FIGS. 1 to 6.

[0042] FIG. 1 is an exploded perspective view of a battery pack according to one embodiment of the present invention; FIG. 2 is an exploded perspective view showing a plurality of all-solid-state battery cells of the battery pack of FIG. 1 and a disk spring between the plurality of all-solid-state battery cells; FIG. 3 is a cross-sectional view taken along line DD' of FIG. 2; FIG. 4 is a perspective view of a disk spring joint; FIG. 5 is a cross-sectional view taken along line AA' of FIG. 1, showing a case and a disk spring mounted in the case; FIG. 6 is a view showing a plurality of all-solid-state battery cells accommodated in the case of FIG. 5;

[0043] Referring to FIGS. 1 to 6, a battery pack according to one embodiment of the present invention includes a plurality of all-solid-state battery cells (10) and a plurality of disk springs (200) arranged between the plurality of all-solid-state battery cells (10). At this time, the plurality of disk springs (200) are arranged in a direction perpendicular to the interface between the negative electrode (14), the solid electrolyte (13), and the positive electrode (12) within the plurality of all-solid-state battery cells (10), thereby pressurizing the interface.

[0044] An all-solid-state battery cell (10) includes a positive electrode (12), a negative electrode (14), and a solid electrolyte (13) between the positive electrode (12) and the negative electrode (14). The positive electrode (12) includes a positive electrode current collector (12a) and a positive electrode active material layer (12b) on one surface of the positive electrode current collector (12a). The negative electrode (14) includes a negative electrode current collector (14a) and a negative electrode active material layer (14b) on one surface of the negative electrode current collector (14a).

[0045] At this time, the positive electrode (12) is arranged with a positive current collector (12a) and a positive active material layer (12b) stacked, the negative electrode (14) is arranged with a negative current collector (14a) and a negative active material layer (14b) stacked, and the disk spring (200) is arranged in a direction perpendicular to the interface between the positive current collector (12a), the positive active material layer (12b), the negative current collector (14a), the negative active material layer (14b) and the solid electrolyte (13), and can pressurize the interface.

[0046] The negative electrode active material layer (14b) may include, for example, a negative electrode active material that can form an alloy or compound with lithium.

[0047] The negative electrode current collector (14a) may be composed of, for example, a material that does not react with lithium, i.e., does not form an alloy or compound.

[0048] The positive electrode active material layer (12b) may include a positive electrode active material capable of reversibly absorbing and desorbing lithium ions. The positive electrode active material may include, for example, an oxide-based positive electrode active material, a sulfide-based positive electrode active material, or a combination thereof.

[0049] The positive electrode current collector (12a) may be, for example, a plate or foil made of indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof. The positive electrode current collector (12a) may be omitted.

[0050] The solid electrolyte (13) may include, for example, a solid electrolyte, or a combination of a solid electrolyte and a gel electrolyte. The solid electrolyte may include, for example, a sulfide-based solid electrolyte, an oxide-based solid electrolyte, a polymer solid electrolyte, or a combination thereof.

[0051] In the case of an all-solid-state battery cell, a solid electrolyte is applied instead of a liquid electrolyte, and when a solid electrolyte is applied, a pressure is required between the negative electrode, solid electrolyte, and positive electrode to densify the solid electrolyte membrane and form an interface between the negative electrode, solid electrolyte, and positive electrode.

[0052] Accordingly, according to the present embodiment, a plurality of disk springs (200) are arranged between a plurality of all-solid-state battery cells (10). Through this, the interface between the negative electrode (14), the solid electrolyte (13), and the positive electrode (12) inside the plurality of all-solid-state battery cells (10) can be activated, thereby reducing the interfacial resistance.

[0053] In addition, through a structure in which a disk spring (200) is placed between a plurality of all-solid-state battery cells accommodated inside the case, the overall mutual pressure between the plurality of all-solid-state battery cells and the case is maintained, so that the battery pack can remain structurally stable.

[0054] In addition, a separate pressurizing process is not required to pressurize the interface of the all-solid-state battery cell, and the problem of interfacial activation between the negative electrode, solid electrolyte, and positive electrode can be structurally solved.

[0055] Referring to FIG. 3, the pressing direction of the disk spring (200) may be a direction perpendicular to the interface between the negative electrode, the solid electrolyte, and the positive electrode of the all-solid-state battery cell (10). Referring to FIG. 1 and FIG. 3, the pressing direction of the disk spring (200) may be a direction parallel to the X-axis direction.

[0056] According to the present embodiment, the disk spring (200) may be insulated. This allows the disk spring (200) positioned between the plurality of all-solid-state battery cells (10) to block any electrical connection that may occur unintentionally between the plurality of all-solid-state battery cells (10).

[0057] The disk spring (200) is shaped like a disk with a hole formed in the center, and is formed by bending the disk-shaped disk spring in both directions, and is formed by bending in a direction perpendicular to the length direction of the disk, so that elastic force can be applied in a direction perpendicular to the length direction of the disk.

[0058] According to the present embodiment, the case (100) may include a disc spring coupling portion (510) that is accommodated and fixes a plurality of disc springs (200) on both sides.

[0059] At this time, the first coupling portion (210) may be further included, which is arranged on each side surface of the disc spring coupling portion (510) and fixes the side surface of the disc spring (200). At this time, the disc spring (200) may be fixed on both sides to the side surface of the disc spring coupling portion (510) by the first coupling portion (210).

[0060] A disk spring coupling portion (510) may be placed between a plurality of stacked all-solid-state battery cells (10) and a case (100). The case (100) may have an open upper surface and may include side surfaces (110, 111) and a lower surface (120). Referring to FIG. 4, the disk spring coupling portion (510) may be formed on both side surfaces of the case (100) with the Y-axis direction being perpendicular to the direction.

[0061] In this way, since the disk spring coupling portion (510) is formed on both sides of the case (100) in a direction perpendicular to the Y-axis direction, durability against force in the X-axis direction can be secured.

[0062] The disk spring coupling portion (510) can be formed at a position corresponding to the case side portion (110) so as to cross the center portion of the case side portion (110) and the center portion of the plurality of all-solid-state battery cells (10).

[0063] A plurality of first coupling portions (210) capable of supporting and fixing a plurality of disc springs (200) may be arranged on the disc spring coupling portion (510). The first coupling portions (210) are arranged at positions corresponding to the positions of the disc spring coupling portions (510), and can support and fix both ends of the plurality of disc springs (200) formed in an annular shape and having the longest diameter in the Y-axis direction.

[0064] These plurality of first connecting portions (210) can be supported and fixed by a disk spring connecting portion (510) that is formed to extend in a direction parallel to the X-axis direction. Since the disk spring (200) exerts elastic force in a direction parallel to the X-axis direction, the disk spring connecting portion (510) can support the pressure of the disk spring (200) transmitted through the first connecting portion (210) in a direction parallel to the X-axis direction.

[0065] Referring further to Fig. 7, a busbar holder (300) may be placed on the upper side of the case (100), and a busbar (400) may be placed on the upper side of the busbar holder (300). At this time, a terminal portion (11) may be placed on the upper side of a plurality of all-solid-state battery cells (10), and the terminal portion (11) may pass through the busbar holder hole (302) of the busbar holder (300) and be coupled to the busbar (400).

[0066] The busbar holder (300) can be coupled with a busbar (400) positioned on the upper side of the busbar holder (300) to secure the busbar (400). In addition, by connecting a terminal portion (11) to a busbar holder hole (302) formed in the busbar holder (300), the busbar holder (300) can maintain a state in which a plurality of all-solid-state battery cells (10) are also coupled together.

[0067] Referring to FIGS. 1 and 7, a hook portion (301) is arranged on the lower side of the busbar holder (300), and the hook portion (301) can be inserted and connected to the hook portion insertion portion (101) formed at the four corners of the case (100). At this time, the hook portion (301) and the hook portion insertion portion (101) can be arranged at positions corresponding to each other on the four corners of the case (100).

[0068] Referring further to FIG. 8, a battery pack according to another embodiment of the present invention may include a second coupling portion (220) that is placed on a busbar holder (300) and fixes an upper portion of a disk spring (200). At this time, the upper portion of the disk spring (200) may be fixed to the busbar holder (300) by the second coupling portion (220).

[0069] In addition, the case (100) may further include a third connecting portion (230) that is arranged on the lower surface (120) and fixes the lower portion of the disk spring (200). At this time, the lower portion of the disk spring (200) may be fixed to the lower surface (120) of the case (100) by the third connecting portion (230).

[0070] In addition to the configuration in which both ends of the disk spring (200) are coupled to the disk spring coupling portion (500), the upper end of the disk spring (200) can be coupled to the bus bar holder (300) via the second coupling portion (220). In addition, the lower end of the disk spring (200) can be fixedly coupled to the lower surface (120) of the case (100) via the second coupling portion (230).

[0071] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

Claims

1. Case; A plurality of all-solid-state battery cells accommodated in the case; and It comprises a plurality of disk springs arranged between the plurality of all-solid-state battery cells, A battery pack in which the plurality of disk springs are arranged in a direction perpendicular to the interface between the negative electrode, the solid electrolyte, and the positive electrode inside the plurality of all-solid-state battery cells, thereby pressurizing the interface.

2. In paragraph 1, Accepted in the above case, A battery pack including a disc spring coupling for fixing the plurality of disc springs.

3. In paragraph 2, It further includes a first coupling part which is arranged on each side surface of the above disc spring coupling part and fixes the side of the disc spring, A battery pack in which the above-mentioned disc spring is fixed on both sides to the side portion of the above-mentioned disc spring coupling portion by the above-mentioned first coupling portion.

4. In paragraph 3, A battery pack wherein the first connecting portion is positioned in the center portion of the disk spring connecting portion.

5. In paragraph 3, further comprising a second connecting member arranged on the busbar holder and fixing the upper portion of the disc spring; A battery pack in which the above-mentioned disc spring is fixed at the upper side to the busbar holder by the above-mentioned second connecting portion.

6. In paragraph 3, It further includes a third connecting part arranged on the lower part of the case and fixing the lower part of the disc spring, A battery pack in which the lower side of the above-mentioned disc spring is fixed to the lower part of the case by the above-mentioned third connecting member.

7. In paragraph 2, A busbar holder is placed on the upper side of the above disc spring joint, A battery pack in which a busbar is arranged on the upper side of the above busbar holder.

8. In paragraph 7, A terminal portion is arranged on the upper side of the above plurality of all-solid-state battery cells, A battery pack in which the terminal portion is connected to the busbar by penetrating the busbar holder hole of the busbar holder.

9. In paragraph 7, A hook part is placed on the lower side of the above bus bar holder, A battery pack in which the hook portion is inserted and connected into a hook portion insert formed at a corner of the case.

10. In paragraph 9, A battery pack in which the hook portion and the hook portion insert portion are positioned at corresponding positions on the four corners of the case.

11. In paragraph 1, The above disc spring is a lead-coated battery pack.

12. In paragraph 1, The above positive electrode is formed by stacking a positive electrode current collector and a positive electrode active material layer, The above negative electrode is formed by laminating a negative electrode current collector and a negative electrode active material layer, A battery pack wherein the above-mentioned disc spring is arranged in a direction perpendicular to the interface between the positive electrode current collector, the positive electrode active material layer, the negative electrode current collector, the negative electrode active material layer, and the solid electrolyte, and pressurizes the interface.

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