Electrode assembly and battery comprising electrode assembly, and battery pack and vehicle comprising battery

Abstract

The electrode assembly according to an embodiment of the present invention has a structure in which a laminate is wound, the laminate having a first electrode, a first separator, a second electrode, and a second separator sequentially laminated therein, wherein a winding center hole formed in a core portion of the electrode assembly by winding the laminate may have a support part provided on the inner wall thereof, so as to increase the stiffness of the inner wall.

Description

Electrode assembly and battery including the same, and battery pack and vehicle including the same

[0001] The present invention relates to an electrode assembly and a battery including the same, and a battery pack and a vehicle including the same.

[0002] This application claims priority to Korean Patent Application No. 10-2022-0187593, filed on December 28, 2022, and Korean Patent Application No. 10-2023-0193316, filed on December 27, 2023, the entire contents of which are disclosed in the specification and drawings of the above applications are incorporated herein by reference.

[0003] Batteries with high applicability according to product group and electrical characteristics such as high energy density are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) driven by electrical power sources.

[0004] These batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency, not only because they can drastically reduce the use of fossil fuels, but also because they produce no byproducts from energy use.

[0005] Currently, widely used battery types include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these unit battery cells ranges from approximately 2.5 V to 4.5 V. Therefore, if a higher output voltage is required, multiple batteries are connected in series to form a battery pack. Furthermore, depending on the required charge / discharge capacity, multiple batteries are connected in parallel to form a battery pack. Therefore, the number of batteries and the electrical connection configuration included in a battery pack can vary depending on the required output voltage and / or charge / discharge capacity.

[0006] Meanwhile, in the case of a cylindrical battery, a jelly roll type electrode assembly having a structure in which a negative electrode (anode), a separator, an anode (cathode), and a separator are sequentially laminated and wound may be accommodated in a roughly cylindrical battery housing.

[0007] The jellyroll-type electrode assembly applied to such cylindrical batteries may have a winding center hole formed in the core portion as the battery is wound. As the battery is repeatedly charged and discharged, the electrodes constituting the electrode assembly may undergo repeated expansion and contraction.

[0008] In cases where expansion and contraction of the electrode are repeated in this way, a core collapse phenomenon may occur, in which the electrode is partially bent on the inner wall of the winding center hole of the electrode assembly and protrudes toward the winding center hole. If this core collapse phenomenon occurs, the risk of a short circuit occurring in the core portion of the electrode assembly increases, making it difficult to ensure the safety of use of the secondary battery.

[0009] Accordingly, there is a need to develop a method to suppress deformation of the core structure of the electrode assembly due to expansion and contraction of the electrode that occurs with repeated charging and discharging of the battery.

[0010] The present invention was created in consideration of the above-described problems, and its primary purpose is to provide an electrode assembly having a structure capable of suppressing deformation of the core structure of the electrode assembly due to expansion and contraction of the electrode that occurs due to repeated charging and discharging of the battery.

[0011] 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.

[0012] An electrode assembly according to one embodiment of the present invention for solving the above-described problem is an electrode assembly having a structure in which a laminate in which a first electrode, a first separator, a second electrode, and a second separator are sequentially laminated is wound, and a support configured to increase the rigidity of the inner wall of a winding center hole formed in a core portion of the electrode assembly by winding the laminate may be provided.

[0013] The first separator may be positioned on the inner surface of the above-mentioned winding center hole.

[0014] The support may include a coating layer formed on at least one of the first separator and the second separator.

[0015] The above coating layer may include a UV curing agent.

[0016] The above coating layer can be formed on the inner surface of the first separator.

[0017] The above support member can be extended at least to a length corresponding to the circumference of the above winding center hole.

[0018] The core portion of the electrode assembly may include a membrane region in which the first and second electrodes are not interposed between the first and second membranes and the first and second membranes are wound at least one turn while directly facing each other.

[0019] The above coating layer can be formed within the separation membrane region.

[0020] The above support member can be provided in a predetermined pattern.

[0021] The above support may be provided in a stripe pattern.

[0022] Each band constituting the above stripe pattern can extend along a direction inclined at an angle greater than 0 degrees and less than 90 degrees with respect to the circumferential direction of the winding center hole.

[0023] A battery according to one embodiment of the present invention for solving the above-described problem may include: an electrode assembly according to one embodiment of the present invention; and a battery housing configured to accommodate the electrode assembly.

[0024] A battery pack according to one embodiment of the present invention for solving the above-described problem may include: a battery according to one embodiment of the present invention; and a pack housing configured to accommodate the battery.

[0025] A vehicle according to one embodiment of the present invention for solving the above-described problem may include a battery pack according to one embodiment of the present invention.

[0026] According to one aspect of the present invention, deformation of the core structure of an electrode assembly due to expansion and contraction of an electrode that occurs due to repeated charging and discharging of a battery can be suppressed, thereby greatly improving the safety of use of a secondary battery.

[0027] However, the advantageous effects derived from the present invention are not limited to the above-described effects, and other advantageous effects not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0028] 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.

[0029] FIG. 1 is a perspective view showing an electrode assembly according to one embodiment of the present invention.

[0030] Figure 2 is a plan view showing an electrode assembly according to one embodiment of the present invention.

[0031] FIG. 3 is a drawing showing a process of winding a laminate constituting an electrode assembly according to one embodiment of the present invention.

[0032] FIG. 4 is an enlarged view showing an area including a core portion of an electrode assembly according to one embodiment of the present invention (the support portion of the present invention is omitted in the drawing).

[0033] FIG. 5 is a drawing for explaining a core collapse phenomenon that occurs when a battery including the electrode assembly illustrated in FIG. 4 is repeatedly charged and discharged.

[0034] FIG. 6 is a drawing showing a structure in which a support portion is provided in a stripe pattern on a part of the electrode (first electrode or second electrode) of the present invention.

[0035] FIG. 7 is a drawing showing a battery according to one embodiment of the present invention.

[0036] FIG. 8 is a drawing showing a battery pack according to one embodiment of the present invention.

[0037] FIG. 9 is a drawing showing a vehicle according to one embodiment of the present invention.

[0038] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that terms and words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of a term to best explain his or her invention. Therefore, 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 spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

[0039]

[0040] First, with reference to FIGS. 1 to 5, an electrode assembly (10) according to one embodiment of the present invention will be described.

[0041] Fig. 1 is a perspective view showing an electrode assembly according to one embodiment of the present invention, and Fig. 2 is a plan view showing an electrode assembly according to one embodiment of the present invention. Fig. 3 is a drawing showing a process of winding a laminate constituting an electrode assembly according to one embodiment of the present invention, and Fig. 4 is an enlarged view showing a region including a core portion of an electrode assembly according to one embodiment of the present invention (a support portion of the present invention is omitted in the drawing). Fig. 5 is a drawing for explaining a core collapse phenomenon that occurs as a battery including the electrode assembly illustrated in Fig. 4 is repeatedly charged and discharged.

[0042] First, referring to FIGS. 1 to 4, an electrode assembly (10) according to one embodiment of the present invention may include a first electrode (11), a second electrode (12), a first separator (13), a second separator (14), and a support (15). The electrode assembly (10) may be, for example, a jelly roll type electrode assembly. The electrode assembly (10) may have a structure in which a laminate (S) in which a first electrode (11), a first separator (13), a second electrode (12), and a second separator (14) are sequentially laminated is wound in one direction.

[0043] The first electrode (11) may be a positive electrode or a negative electrode. The first electrode (11) may have a structure in which a first electrode active material is coated on one side or both sides of a thin metal foil, for example. The second electrode (12) may be an electrode having a polarity opposite to that of the first electrode (11). The second electrode (12) may have a structure in which a second electrode active material is coated on one side or both sides of a thin metal foil, for example. Although not specifically illustrated in the drawings of the present invention for convenience of illustration, the first electrode (11) may include a first uncoated portion on which the first electrode active material is not coated, and similarly, the second electrode (12) may include a second uncoated portion on which the second electrode active material is not coated. When the first electrode (11) is a negative electrode and the second electrode (12) is an positive electrode, the area of ​​the first electrode (11) in the laminate (S) may be formed to be larger than the area of ​​the second electrode (12).

[0044] The above support member (15) may be provided on the inner wall of the winding center hole (10a) formed in the core portion of the electrode assembly (10) by winding the laminate (S). The above support member (15) may be configured to increase the rigidity of the inner wall of the winding center hole (10a).

[0045] As described above, the electrode assembly (10) of the present invention has a support member (15) provided on the inner wall of the winding center hole (10a), thereby significantly reducing the risk of a short circuit occurring due to a core collapse phenomenon in the core portion of the electrode assembly (10) caused by repeated charging and discharging of a battery including the electrode assembly (10).

[0046] In general, when the expansion and contraction of the electrodes constituting the electrode assembly (10) are repeated due to repeated charging and discharging of the battery, a phenomenon in which the end of the first electrode (11) in the core portion of the electrode assembly (10) is bent toward the core may occur, as illustrated in FIG. 5. This bending of the end of the first electrode (11) may cause damage to the first separator (13) forming the inner wall surface of the winding center hole (10a), which may increase the risk of a short circuit occurring in an area adjacent to the core portion of the electrode assembly (10). Therefore, when a structure capable of improving the rigidity of the core portion of the electrode assembly (10) is applied, as in the present invention, the problem caused by this core collapse phenomenon can be solved.

[0047]

[0048] A first separator (13) may be positioned on the inner surface of the winding center hole (10a). In the laminate (S), the first separator (13) may be interposed between the first electrode (11) and the second electrode (12). The second separator (14) may be provided on the outermost side of the laminate (S). The first separator (13) may be positioned on the inner surface of the winding center hole (10a) when the laminate (S) is wound in one direction. The second separator (14) may be configured to cover the outer surface of the electrode assembly (10) when the laminate (S) is wound in one direction.

[0049] The above support member (15) may include a coating layer formed on at least one of the first separator (13) and the second separator (14). When the support member (15) is provided in a form coated on the first separator (13) and / or the second separator (14), there is no need to add a process such as inserting a separate component into the core member, which may be advantageous not only in terms of processability and productivity but also in terms of energy density.

[0050] When the support member (15) is provided in the form of a coating layer, the coating layer may include a UV curing agent. In this case, the support member (15) may be cured by irradiating UV (ultraviolet rays) at a desired time after coating the UV curing agent on the first separator (13) and / or the second separator (14). The time point at which the UV curing agent is cured may be after or before the stack (S) is wound. The time point at which the curing process is performed may be determined by considering the coating thickness and / or coating area of ​​the UV curing agent, etc. In a case where the first separator (13) and / or the second separator (14) can be easily wound even in a state where the coating layer is cured, it may be advantageous to perform the curing process before the stack (S) is wound. Conversely, if the first separator (13) and / or the second separator (14) is not easy to wind when the coating layer is cured and there is concern about damage to the first separator (13) and / or the second separator (14) during winding, it may be advantageous to perform the curing process after winding the laminate (S).

[0051]

[0052] The above coating layer may be formed on the inner surface of the first separator (13). In this case, the coating layer may be provided on the inner wall surface of the winding center hole (10a) of the electrode assembly (10). Therefore, curing of the coating layer by UV irradiation is possible after winding the laminate (S). That is, the coating layer may be exposed through the winding center hole (10a) formed during winding of the laminate (S), and thus, the coating layer may be cured by irradiating UV into the winding center hole (10a).

[0053] However, the formation location of the coating layer of the present invention is not limited thereto, and the coating layer may be formed on the inner surface of the first separator (13) and / or the outer surface of the first separator (13) and / or the inner surface of the second separator (14) and / or the outer surface of the second separator (14).

[0054]

[0055] The above support member (15) may extend at least to a length corresponding to the circumference of the winding center hole (10a). The support member (15) may be configured to surround the core part of the electrode assembly (10) at least once. The support member (15) may be configured to cover the inner wall surface of the winding center hole (10a) of the electrode assembly (10) at least once.

[0056] When the support member (15) is provided in this manner, the rigidity of the entire circumference of the core portion of the electrode assembly (10) can be improved, and accordingly, even if the battery is repeatedly charged and discharged, deformation of the core portion structure can be prevented or minimized. When deformation of the core portion structure is suppressed in this way, for example, the occurrence of micro-shorts due to unnecessary electrical contact in the core portion can be prevented.

[0057]

[0058] The core portion of the electrode assembly (10) may include a region (hereinafter referred to as a “separator region”) in which the first electrode (11) and the second electrode (12) are not interposed between the first separator (13) and the second separator (14) and the first separator (13) and the second separator (14) are wound at least one turn while directly facing each other.

[0059] Referring to FIGS. 3 and 4 together, when the first separator (13) and the second separator (14) extending further outward than the longitudinal end borders of the first electrode (11) and the second electrode (12) are held using a winding tool (M) and wound in the direction of the arrow in FIG. 3, there may be an area where only the first separator (13) and the second separator (14) are wound in a state where they overlap each other, excluding the first electrode (11) and the second electrode (12).

[0060] In this case, the first electrode (11) and the second electrode (12) are excluded, and only the first separator (13) and the second separator (14) overlap each other to form the separator region by covering the winding center hole (10a) by at least one turn. The support member (15) may be provided on at least a part of the separator region. When the support member (15) is a coating layer formed on the first separator (13) and / or the second separator (14), the coating layer may be formed within the separator region.

[0061] The length (D) of the region where the support portion (15) is formed may be a length capable of covering the core portion at least once. In this way, when the support portion (15) is formed to a length that covers the core portion at least once, the core portion of the electrode assembly (10) can be effectively reinforced.

[0062]

[0063] Next, with reference to FIG. 6 along with FIG. 1 to FIG. 3, a structure in which a support portion (15) is provided in a stripe pattern on an electrode (11, 12) of the present invention will be described.

[0064] FIG. 6 is a drawing showing a structure in which a support portion is provided in a stripe pattern on a part of the electrode (first electrode or second electrode) of the present invention.

[0065] Referring to FIG. 6 together with FIGS. 1 to 3, the support portion (15) of the present invention may be provided in a predetermined pattern. The support portion (15) may be provided in a stripe pattern, for example. When the support portion (15) is provided in a predetermined pattern, the phenomenon of the elasticity of the core portion of the electrode assembly (10) being excessively suppressed can be prevented. In this way, when the support portion (15) is provided in a predetermined pattern and the elasticity of the first separator (13) and / or the second separator (14) is partially secured, the stress due to expansion and contraction of the electrode assembly (10) can be prevented from being excessively accumulated in the core portion.

[0066] In another aspect, when the support (15) is provided in a predetermined pattern, the phenomenon of the impregnation speed of the electrolyte through the core being reduced due to the formation of the support (15) for reinforcing the core of the electrode assembly (10) can be minimized. The first separator (13) and / or the second separator (14) may have porosity. Therefore, the electrolyte can permeate into the interior of the electrode assembly (10) through the inner wall of the winding center hole (10a) of the electrode assembly (10) covered by the first separator (13) and / or the second separator (14). However, when the support (15) is formed on at least one surface of the first separator (13) and / or the second separator (14), the permeation of the electrolyte may be hindered. Therefore, when the support member (15) is provided in a predetermined pattern on the inner wall of the winding center hole (10a), the influence on the impregnation property of the electrolyte can be minimized.

[0067] When the above support member (15) is provided in a stripe pattern, each band constituting the stripe pattern can extend along the circumferential direction of the winding center hole (10a), i.e., along a direction inclined at a predetermined angle (θ) with respect to the winding direction of the electrode assembly (10). The angle (θ) can be approximately greater than 0 degrees and less than 90 degrees.

[0068] If each band constituting the stripe pattern extends along a direction substantially parallel to the winding direction of the electrode assembly (10), there is no region in which the support portion (15) is omitted along the circumferential direction of the electrode assembly (10), so it may be difficult to partially secure the elasticity of the first separator (13) and / or the second separator (14). In addition, if each band constituting the stripe pattern extends along a direction substantially perpendicular to the winding direction of the electrode assembly (10), there is a region in which the support portion (15) is partially absent along the circumferential direction of the electrode assembly (10), so it may be difficult to effectively reinforce the first separator (13) and / or the second separator (14).

[0069]

[0070] Next, a battery (1) according to one embodiment of the present invention will be described with reference to FIG. 7 together with FIG. 1.

[0071] FIG. 7 is a drawing showing a battery according to one embodiment of the present invention.

[0072] Referring to FIG. 7 together with FIG. 1, a battery (1) according to one embodiment of the present invention may include an electrode assembly (10) of the present invention and a battery housing (20) configured to accommodate the electrode assembly (10). The battery (1) may be, for example, a cylindrical battery.

[0073] Next, a battery pack (3) according to one embodiment of the present invention will be described with reference to FIG. 8.

[0074] FIG. 8 is a drawing showing a battery pack according to one embodiment of the present invention.

[0075] Referring to FIG. 8, a battery pack (3) according to an embodiment of the present invention may include a battery (1) of the present invention. The battery pack (3) may include an assembly in which a plurality of batteries (1) are electrically connected and a pack housing (2) that accommodates them. In the drawing, for convenience of illustration, components such as a bus bar, a cooling unit, and an external terminal for electrical connection of the batteries (1) are omitted.

[0076] Next, a vehicle (5) according to one embodiment of the present invention will be described with reference to FIG. 9.

[0077] Figure 9 is a drawing showing a vehicle according to one embodiment of the present invention.

[0078] Referring to FIG. 9, the automobile (5) may include a battery pack (3) of the present invention. The battery pack (3) may be mounted on the automobile (5). The automobile (5) of the present invention may be, for example, an electric automobile, a hybrid automobile, or a plug-in hybrid automobile. The automobile may include a four-wheeled automobile or a two-wheeled automobile. The automobile (5) may be configured to operate by receiving power from the battery pack (3) according to an embodiment of the present invention.

[0079]

[0080] 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.

[0081]

[0082] [Explanation of symbols]

[0083] 10: Electrode assembly

[0084] S: Laminate

[0085] 11: First electrode

[0086] 12: Second electrode

[0087] 13: First membrane

[0088] 14: Second membrane

[0089] 15: Support

[0090] M: Winding tool

[0091] 20: Battery housing

[0092] 1: Battery

[0093] 2: Pack housing

[0094] 3: Battery pack

[0095] 5: Car

Claims

1. In an electrode assembly having a structure in which a first electrode, a first separator, a second electrode, and a second separator are sequentially laminated, the structure being wound up, An electrode assembly characterized in that the inner wall of the winding center hole formed in the core portion of the electrode assembly by winding the laminate is provided with a support configured to increase the rigidity of the inner wall.

2. In paragraph 1, An electrode assembly characterized in that the first separator is positioned on the inner surface of the above-mentioned winding center hole.

3. In paragraph 2, The above support part, An electrode assembly characterized by including a coating layer formed on at least one of the first separator and the second separator.

4. In paragraph 3, The above coating layer is, An electrode assembly characterized by comprising a UV curing agent.

5. In paragraph 4, The above coating layer is, An electrode assembly characterized in that it is formed on the inner surface of the first separator.

6. In paragraph 1, The above support part, An electrode assembly characterized in that it extends at least as long as the circumference of the center hole of the coil.

7. In paragraph 3, The core part of the above electrode assembly is, An electrode assembly characterized in that it includes a separator region in which the first separator and the second separator are wound at least one turn while directly facing each other without the first electrode and the second electrode being interposed between the first separator and the second separator.

8. In paragraph 7, The above coating layer is, An electrode assembly characterized in that it is formed within the above-mentioned separator region.

9. In paragraph 1, The above support part, An electrode assembly characterized by being provided with a predetermined pattern.

10. In paragraph 9, The above support part, An electrode assembly characterized by being provided with a stripe pattern.

11. In paragraph 10, Each band that makes up the above stripe pattern is, An electrode assembly characterized in that it extends along a direction inclined at an angle greater than 0 degrees and less than 90 degrees with respect to the circumferential direction of the above-mentioned winding center hole.

12. An electrode assembly according to any one of claims 1 to 11; and A battery housing configured to accommodate the electrode assembly; A battery containing .

13. Batteries according to Article 12; and A pack housing configured to accommodate the above battery; Battery pack containing.

14. A vehicle comprising a battery pack according to Article 13.

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