Battery pack

Abstract

The present disclosure provides a battery pack including: a battery cell including an electrode assembly in a case and including one or more electrode tabs; and a fixing member between the battery cells to fix the battery cells, and defining a through hole penetrating from one end of the fixing member to the other end of the fixing member.

Description

Technical Field

[0001] Aspects of embodiments of the present disclosure relate to a battery pack. Background Art

[0002] A secondary battery is a battery that can be charged and discharged, different from a primary battery that cannot be recharged. A low-capacity battery in which one battery cell is encapsulated in a group can be used for small portable electronic devices such as smartphones and digital cameras, while a high-capacity battery in the form of a module in which dozens to hundreds of battery packs are connected can be used as a power source for driving motors of hybrid vehicles, electric vehicles, power tools, hand cleaners, or drones, or can be used as an energy storage device.

[0003] The battery pack can be configured using cylindrical cells or pouch cells. If the battery pack is configured using pouch cells, compared with cylindrical cells, the output power can be increased and the weight of the group can be reduced in the same area. The secondary battery can include an electrode assembly composed of a positive electrode and a negative electrode, a case accommodating the electrode assembly, and electrode terminals connected to the electrode assembly.

[0004] The above information disclosed in this background art section is only for enhancing the understanding of the background of the present disclosure, and thus may include information that does not constitute related art. Summary of the Invention

[0005] Aspects of embodiments of the present disclosure may relate to a battery pack in which perforations are formed / defined in a fixing member (which is located between corresponding cells and configured to fix the corresponding cells), so that cell movement can be suppressed, and thus cell swelling can be absorbed.

[0006] However, aspects of the present disclosure are not limited to those described above, and other aspects not mentioned can be clearly understood by those skilled in the art from the description of the present disclosure provided below.

[0007] One aspect of the present disclosure provides a battery pack, including: battery cells including an electrode assembly in a case and including one or more electrode tabs; and a fixing member that is between the battery cells to fix the battery cells and defines a through hole that penetrates from one end of the fixing member to the other end of the fixing member.

[0008] The through hole may have a circular cross-section.

[0009] The through hole may have an elliptical cross-section having a major axis parallel to the width direction of the battery cell.

[0010] The fixing member may include at least one of silicone rubber, polyurethane, or ethylene vinyl acetate (EVA).

[0011] The minimum diameter of the through-hole can correspond to the compression rate of the fixing member based on the swelling of the battery cell.

[0012] The fixing member can have a hexahedral shape including four side surfaces and two wide surfaces, and the two wide surfaces contact the battery cell.

[0013] The through-hole can penetrate from one of the four side surfaces to the other side surface opposite thereto among the four side surfaces.

[0014] The through-hole can be parallel to the longitudinal direction of the battery cell.

[0015] The through-hole can be parallel to the direction in which the electrode tab protrudes.

[0016] The through-hole can be perpendicular to the longitudinal direction of the battery cell.

[0017] The through-holes can be arranged side by side.

[0018] The through-hole can include a first through-hole parallel to the longitudinal direction of the battery cell and a second through-hole perpendicular to the longitudinal direction of the battery cell.

[0019] The first through-hole and the second through-hole can cross each other.

[0020] The area of one of the two wide surfaces of the fixing member can be less than or equal to the area of the surface of the battery cell that contacts the one of the two wide surfaces.

[0021] The fixing member can further include an adhesive member at at least one of the two wide surfaces.

[0022] The minimum thickness of the fixing member between the surface of the remaining portion of the fixing member other than the adhesive member and one of the through-holes can be about 10% to about 30% of the maximum thickness of the fixing member between the two wide surfaces.

[0023] The adhesive member can include an acrylic material.

[0024] The adhesive member can have an adhesive strength of about 1300 g / 25.4 mm or greater.

[0025] The adhesive member can have a thickness of about 10% or less of the thickness of the remaining portion of the fixing member other than the adhesive member.

[0026] The battery cells can be stacked in a stacked type. Description of the Drawings

[0027] Figure 1 is a perspective view of a battery cell according to one or more embodiments of the present disclosure.

[0028] Figure 2 is by Figure 1Perspective view of a battery pack composed of battery cells.

[0029] Figure 3 Is a perspective view of a fixing member according to one or more embodiments of the present disclosure, wherein through holes are formed parallel to the longitudinal direction (y-axis direction) of the battery cell.

[0030] Figure 4 Is a perspective view of a fixing member according to one or more embodiments of the present disclosure, wherein through holes are formed perpendicular to the longitudinal direction (y-axis direction) of the battery cell.

[0031] Figure 5A and Figure 5B Is a perspective view and a cross-sectional view of a fixing member according to one or more embodiments of the present disclosure, wherein through holes are formed parallel to and perpendicular to the longitudinal direction (y-axis direction) of the battery cell.

[0032] Figure 6 Is a front view of a fixing member according to one or more embodiments of the present disclosure, wherein circular through holes are formed.

[0033] Figure 7 Is a front view of a fixing member according to one or more embodiments of the present disclosure, wherein substantially elliptical through holes are formed. Detailed Description of Specific Embodiments

[0034] With reference to the detailed description of the embodiments and the drawings, aspects of some embodiments of the present disclosure and their implementation methods can be more easily understood. The described embodiments are provided as examples so that the present disclosure will be thorough and complete, and will fully convey the aspects of the present disclosure to those skilled in the art. Therefore, processes, elements, and techniques that are redundant, irrelevant to the description of the embodiments, or not necessary for those of ordinary skill in the art to fully understand the aspects of the present disclosure can be omitted. Unless otherwise noted, throughout the drawings and the written description, the same reference numerals, characters, or combinations thereof represent the same elements, and thus, repeated descriptions thereof can be omitted.

[0035] The described embodiments can have various modifications and can be implemented in different forms and should not be construed as limited to the embodiments shown herein. The use of "can", "may", or "may not" when describing embodiments corresponds to one or more embodiments of the present disclosure. The present disclosure covers all modifications, equivalents, and substitutions within the spirit and scope of the present disclosure. In addition, each feature of the various embodiments of the present disclosure can be partially or wholly combined with each other, and various interlocks and drives are technically possible. Each embodiment can be implemented independently of each other or can be implemented together.

[0036] In the drawings, for clarity and / or description purposes, the relative dimensions of elements, layers, and regions may be exaggerated. Here, various embodiments are described with reference to sectional views, which are schematic illustrations of the embodiments and / or intermediate structures. Thus, variations in the shapes of the illustrations due to, for example, manufacturing techniques and / or tolerances are to be expected. In addition, for the purpose of describing embodiments in accordance with the concepts of the present disclosure, the specific structural or functional descriptions disclosed herein are merely illustrative. Accordingly, the embodiments disclosed herein should not be construed as limited to the shapes of the elements, layers, or regions shown, but include, for example, deviations in shape caused by manufacturing.

[0037] For ease of explanation, spatial relationship terms such as "beneath", "below", "under", "underside", "underneath", "above", "on", "upper side", etc. may be used herein to describe the relationship of one element or feature to another element or feature as shown in the figures. It will be understood that, in addition to the orientation depicted in the figures, spatial relationship terms are intended to encompass different orientations of the device during use or operation. For example, if the device in the figures is flipped, an element described as "beneath", "below", or "underneath" another element or feature will be oriented "above" the other element or feature. Thus, the example terms "beneath" and "underneath" can encompass both an above and a below orientation. The device may be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relationship descriptors used herein should be interpreted accordingly. Similarly, when a first part is described as being disposed "on" a second part, this means that the first part is disposed at the upper side or the lower side of the second part, and is not limited to the upper side of the second part based on the direction of gravity.

[0038] In addition, the phrase "in a plan view" means when observing a part of an object from above, and the phrase "in a schematic sectional view" means when observing a schematic section taken by vertically cutting a part of an object from the side. The terms "overlap" or "overlapped by" mean that a first object may be above, below, or on one side of a second object, and vice versa. In addition, the term "overlap" may include stacking, facing or facing..., extending above, covering or partially covering, or any other suitable term as would be recognized and understood by a person of ordinary skill in the art. The expression "not overlap" may include meanings such as "separated from", "set aside from", "deviated from", and any other suitable equivalents as would be recognized and understood by a person of ordinary skill in the art. The terms "face" and "facing" may mean that a first object may be directly or indirectly opposite a second object. In the case where a third object is between the first object and the second object, the first object and the second object may be understood to be indirectly opposite each other, although still facing each other.

[0039] It will be understood that when an element, layer, region or component is referred to as being "formed on", "on", "connected to", or "(operatively or communicatively) coupled to" another element, layer, region or component, it can be directly formed on, directly on, directly connected to, directly coupled to, or indirectly formed on, indirectly on, indirectly connected to, indirectly coupled to another element, layer, region or component such that there can be one or more intermediate elements, layers, regions or components. Further, this can commonly mean direct or indirect coupling or connection and integral or non-integral coupling or connection. For example, when a layer, region or component is referred to as being "electrically connected" or "electrically coupled" to another layer, region or component, it can be directly electrically connected or coupled to another layer, region and / or component, or there can be one or more intermediate layers, regions or components. The one or more intermediate components can include switches, resistors, capacitors, etc. When describing embodiments, unless explicitly described as a direct connection, the expression of connection means an electrical connection, and "direct connection / direct coupling" or "directly on" means that one component is directly connected or coupled to another component, or on another component, without an intermediate component.

[0040] Further, in this specification, when a part of a layer, film, region, plate, etc. is formed on another part, the forming direction is not limited to the upward direction, but includes forming the part on a side surface or in a downward direction. Conversely, when a part of a layer, film, region, plate, etc. is formed "under" another part, this includes not only the case where the part is directly under the other part, but also the case where there is another part between the part and the other part. At the same time, other expressions describing the relationship between components, such as "between", "immediately between", or "adjacent to" and "directly adjacent to", can be similarly interpreted. It will be understood that when an element or layer is referred to as being "between" two elements or layers, it can be the only element or layer between the two elements or layers, or there can also be one or more intermediate elements or layers.

[0041] For the purposes of the present disclosure, expressions such as "at least one of...", "any one of...", or "one or more of...", when following a list of elements, modify the entire list of elements and not individual elements within the list. For example, "at least one of X, Y, and Z", "at least one of X, Y, or Z", "at least one selected from the group consisting of X, Y, and Z", and "at least one selected from the group consisting of X, Y, or Z" can be interpreted as only X, only Y, only Z, or any combination of two or more of X, Y, and Z, such as, for example, XYZ, XYY, YZ, and ZZ or any of their variants. Similarly, the expressions "at least one of A and B" and "at least one of A or B" can include A, B, or A and B. As used herein, "or" generally means "and / or", and the term "and / or" includes any and all combinations of one or more of the associated listed items. For example, the expression "A and / or B" can include A, B, or A and B. Similarly, expressions such as "at least one of...", "a plurality of...", "one of...", and other prepositional phrases, when before / after a list of elements, modify the entire list of elements and not individual elements within the list.

[0042] It will be understood that although the terms "first", "second", "third", etc. may be used herein to describe various elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms do not correspond to a particular order, position, or superiority, but are only used to distinguish one element, member, component, region, zone, layer, section, or part from another element, member, component, region, zone, layer, section, or part. Thus, without departing from the spirit and scope of the present disclosure, the first element, component, region, layer, or section described below can be referred to as the second element, component, region, layer, or section. Describing an element as a "first" element does not require or imply the existence of a second element or other elements. The terms "first", "second", etc. can also be used herein to distinguish different categories or different groups of elements. For the sake of brevity, the terms "first", "second", etc. can represent "first category (or first group)", "second category (or second group)", etc., respectively.

[0043] In an example, the x-axis, y-axis, and / or z-axis are not limited to the three axes of a rectangular coordinate system and can be interpreted in a broader sense. For example, the x-axis, y-axis, and z-axis can be perpendicular to each other, or can represent different directions that are not perpendicular to each other. This also applies to the first direction, second direction, and / or third direction.

[0044] The terms used herein are for the purpose of describing embodiments only and are not intended to limit the present disclosure. As used herein, the singular form "a" is intended to also include the plural form, and the plural form is also intended to include the singular form, unless the context clearly indicates otherwise. It will also be understood that when used in this specification, the terms "comprising", "comprising... of", "having", "having... of", "including" and "including... of" specify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0045] As used herein, the terms "substantially", "about", "approximately" and similar terms are used as approximate terms and not as terms of degree, and are intended to account for the inherent deviations of measured or calculated values that would be recognized by a person of ordinary skill in the art. For example, "substantially" may include a range of + / - 5% of the corresponding value. As used herein, "about" or "approximately" includes the stated value and means within an acceptable deviation range of the particular value determined by a person of ordinary skill in the art in view of the measurements discussed and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "about" may mean within one or more standard deviations, or within + / - 30%, 20%, 10%, 5% of the stated value. Additionally, in describing embodiments of the present disclosure, the use of "may" refers to "one or more embodiments of the present disclosure".

[0046] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by a person of ordinary skill in the art to which this disclosure pertains. It will also be understood that terms (such as those defined in a general dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and / or the context of this specification, and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0047] In the following, in an illustrative example of a prismatic battery according to one or more embodiments of the present disclosure, a battery selected from the prismatic battery is described as having a conventional structure. The conventional structure of the prismatic battery is described with respect to techniques for conventional applications. However, the present disclosure is not limited thereto, and the housing may be configured in various shapes, such as a circular shape or a pouch shape. In one or more embodiments, the housing may be made of metal (such as aluminum, aluminum alloy or nickel-plated steel), or may be made of a laminated film or plastic for forming a pouch.

[0048] Figure 1 is a perspective view of a battery cell according to one or more embodiments of the present disclosure, Figure 2 is composed of Figure 1 a battery pack of battery cells.

[0049] Depending on the shape of the battery and according to different embodiments, the battery cell 10 may be a cylindrical, prismatic, or pouch-type battery cell. Figure 1 A pouch-type battery cell 10 is shown. Figure 2 Some of the multiple battery cells of the battery pack are partially shown.

[0050] Reference Figure 1 and Figure 2 According to one or more embodiments of the present disclosure, the battery pack 1 may include two or more battery cells 10 and a cell holder through which the battery cells 10 are assembled. The cell holder is used to support the multiple battery cells 10, and the multiple battery cells 10 are assembled to be inserted into the cell holder to maintain a fixed position. The cell holder may structurally bundle the multiple battery cells 10 into a module unit. The multiple battery cells 10 may be arranged in one direction such that the corresponding wide surfaces of the battery cells 10 face each other.

[0051] In one or more embodiments, the battery pack 1 may include one or more battery modules (in which multiple battery cells 10 are assembled) and a pack housing (in which an accommodation space is formed to accommodate the one or more battery modules). The battery module may include multiple battery cells 10 and a module housing.

[0052] The battery cell 10 may include a receiving portion A that houses the electrode assembly 100 and a sealing portion TS that extends along the edge of the receiving portion A to seal the receiving portion A. The electrode assembly 100 may be in a wound form, in which a first electrode plate 110 and a second electrode plate 120 facing each other are wound and a separator 130 is interposed therebetween. The electrode assembly 100 may be in a stacked form, in which the first electrode plate 110 and the second electrode plate 120 are stacked and the separator 130 is interposed therebetween.

[0053] The electrode tab 150 that forms a charge / discharge path may be connected to the electrode assembly 100. The electrode tab 150 may include two electrode tabs 150 of different polarities that are electrically connected to the electrode assembly 100. The electrode tab 150 connected to the electrode assembly 100 within the receiving portion A may be led outwards through the front surface F of the receiving portion A. The electrode tab 150 may include a positive electrode tab 151 and a negative electrode tab 152.

[0054] The receiving portion A that houses the electrode assembly 100 may be formed in a substantially rectangular parallelepiped shape. In some examples, the exterior of the battery cell 10 may generally follow the exterior of the receiving portion A.

[0055] In one or more embodiments, the receiving part A may include a front surface F from which the electrode tab 150 is led out and a rear surface R opposite to the front surface F. The receiving part A may include a pair of main surfaces M connecting the front surface F and the rear surface R and a pair of side surfaces D connecting the front surface F and the rear surface R. The main surface M may occupy the largest area among the surfaces of the receiving part A. The main surface M and the side surface D may be formed in pairs at positions opposite to each other. For example, the main surface M may include a first main surface M1 and a second main surface M2 opposite to each other. In one or more embodiments, the electrode assembly 100 is formed on Figure 1 the first main surface M1 and the second main surface M2 of the receiving part A in, but a recess having a depth may be formed only in one of the first main surface M1 or the second main surface M2 to accommodate the electrode assembly 100.

[0056] The receiving part A for accommodating the electrode assembly 100 and the sealing part TS for sealing the receiving part A may be formed of an outer decorative material 200 that is continuously formed to surround the outside of the electrode assembly 100. The outer decorative material 200 may be formed of a flexible outer decorative material (such as a bag). In one or more embodiments, the outer decorative material 200 may include a metal layer 200a (such as an aluminum sheet), and may include insulating layers 200b (such as resin coatings) formed on both surfaces of the metal layer 200a. In this case, the metal layer 200a may be exposed to the outside through a cross-section where the outer decorative material 200 terminates here.

[0057] In some examples, the outer decorative material 200 may include a first outer decorative material 210 and a second outer decorative material 220, and the first outer decorative material 210 and the second outer decorative material 220 are combined to face each other with the electrode assembly 100 interposed therebetween. When the electrode assembly 100 is interposed between the first outer decorative material 210 and the second outer decorative material 220, the first outer decorative material 210 and the second outer decorative material 220 may be folded through a folding part 250 to be stacked on each other, and the folding part 250 connects the first outer decorative material 210 and the second outer decorative material 220 to each other. Thereafter, portions where the edge regions of the first outer decorative material 210 and the second outer decorative material 220 are in contact with each other may be joined to each other by heat fusion or the like, so that an inner region of the first outer decorative material 210 and the second outer decorative material 220 (which face each other and the electrode assembly 100 is interposed therebetween) may be formed as the receiving part A, and an edge region where the first outer decorative material 210 and the second outer decorative material 220 are joined to each other may be formed as the sealing part TS.

[0058] The sealing portion TS may include a platform portion T extending toward the front surface F of the receiving portion A and a side sealing portion S extending toward the side surface of the receiving portion A. In this case, the electrode tab 150 connected to the electrode assembly 100 within the receiving portion A may be led out from the receiving portion A through the platform portion T extending toward the front surface F of the receiving portion A. In one or more embodiments, the protection circuit module may be disposed on the platform portion T, and the electrode tab 150 led out through the platform portion T may be bent to connect to the protection circuit module disposed on the platform portion T.

[0059] The side sealing portion S may include a main body Sb of the side sealing portion S at a position corresponding to the receiving portion A and a front end Sa of the side sealing portion S extending from the main body Sb of the side sealing portion S to a position separated from the receiving portion A. The side sealing portion S may be folded toward the receiving portion A to reduce the area occupied by the entire battery cell 10.

[0060] In one or more embodiments, a battery pack 1 using high output power (such as a battery pack for power tools and hand cleaners) may generally be composed of circular cells assembled in series and parallel. In one or more embodiments, pouch cells may be used to increase the output power within the same area while reducing the weight of the pack. Different from circular cells, in a pack configuration using pouch cells, each cell may be stacked in a stacked type to be configured within a secured area. To stack the pouch cells, fixing members such as fixing straps may be used to assemble and fix the cells.

[0061] The material of the fixing strap may be polyurethane, silicone, etc. Suitable properties of the fixing strap may include mechanically combining and connecting the corresponding adhesion level (high adhesion treatment) of each cell, and a material (high hardness material) that should be adopted to reduce or minimize the movement of each cell in the longitudinal direction (y direction) under external impacts (such as dropping). In one or more embodiments, in order to reduce or minimize the useless space due to the strap volume (thickness), it may be suitable to have a buffering (compression) force to absorb the swelling that occurs during the life reduction of the pouch cell.

[0062] Generally, a trade-off may be made between a high hardness material for suppressing movement and a material having an excellent compression ratio. For example, regarding buffering materials (such as sponge and rubber), for the sponge type (such as a material having an excellent compression ratio), the thickness may be selected by considering the swelling of the cell as much as the compression ratio, although the movement of the cell may not be suppressed, and thus some cells may be impacted during dropping. In one or more embodiments, the rubber type (such as a material having a relatively high hardness) may be effective in suppressing the movement of the cell, although the rubber type may not be effective in absorbing the amount of swelling of the cell, which may result in volume loss.

[0063] One or more embodiments of the present disclosure provide a fixing member 20 that can ensure high hardness to inhibit the movement of the battery cell 10 in the longitudinal direction (y direction), and can ensure a high compression ratio to absorb the swelling in the stacking direction (z direction). In some examples, the fixing member 20 can be manufactured with such a design that through holes are formed in the fixing member by an extrusion molding method based on a material having high hardness. In the longitudinal direction (y direction) of the battery cell 10, the hardness of the raw material can be maintained as much as possible to inhibit the movement of the cell, and in the stacking direction (z direction), when an external force (cell swelling) is applied, the compression ratio can be increased by perforation. The structure of the fixing member 20 will be described below.

[0064] Figure 3 is a perspective view of a fixing member according to one or more embodiments of the present disclosure, in which through holes are formed parallel to the longitudinal direction y of the battery cell. Figure 4 is a perspective view of a fixing member according to one or more embodiments of the present disclosure, in which through holes are formed perpendicular to the longitudinal direction y of the battery cell. Figure 5A and Figure 5B are a perspective view and a cross-sectional view of a fixing member according to one or more embodiments of the present disclosure, in which through holes are formed parallel to and perpendicular to the longitudinal direction y of the battery cell. Figure 6 is a front view of a fixing member according to one or more embodiments of the present disclosure, in which circular through holes are formed. Figure 7 is a front view of a fixing member according to one or more embodiments of the present disclosure, in which substantially elliptical through holes are formed.

[0065] Figures 3 to 7 is a view showing the fixing member 20, Figure 2 a part of the fixing member 20 is enlarged. In the drawings, for ease of illustration, the dimensions of the through holes and the intervals between the through holes may be exaggerated.

[0066] Reference Figures 3 to 7 , a plurality of through holes 21 and 22 are formed to pass through the fixing member 20 from one end to the other end of the fixing member 20. In some examples, the fixing member 20 may have a hexahedral shape composed of four side surfaces and two wide surfaces (which individually contact the corresponding battery cells of the plurality of battery cells 10) and located between adjacent battery cells of the battery cells 10. The plurality of through holes 21 and 22 of the fixing member 20 may penetrate from one of the four side surfaces to the opposite side surface. The through holes 21 and 22 may be arranged side by side.

[0067] Reference Figure 3, a plurality of through-holes 21 may be parallel to the longitudinal direction (y-direction) of the plurality of battery cells 10. In some examples, the plurality of through-holes 21 may be parallel to the direction (y-direction) in which the electrode connection tabs 150 of the plurality of battery cells 10 protrude. Since the protruding portions of the electrode connection tabs 150 may be most vulnerable to damage during dropping, the plurality of through-holes 21 may correspond to the longitudinal direction (y-direction) of the plurality of battery cells 10 in accordance with the tab portions.

[0068] The present disclosure is not limited thereto. Referring to Figure 4 , a plurality of through-holes 22 may be perpendicular to the longitudinal direction (y-direction) of the plurality of battery cells 10.

[0069] Figure 5A is a perspective view of the fixing member 20, in which a first through-hole 21 and a second through-hole 22 are formed in the y-direction and the x-direction, respectively. Figure 5B is a cross-sectional plan view taken along line 5b-5b in Figure 5A . Referring to Figure 5A and Figure 5B , the plurality of through-holes 21 and 22 may include a first through-hole 21 parallel to the longitudinal direction (y-direction) of the plurality of battery cells 10 and a second through-hole 22 perpendicular to the longitudinal direction (y-direction) of the plurality of battery cells 10. In this case, the first through-hole 21 and the second through-hole 22 may intersect each other perpendicularly.

[0070] Referring to Figure 6 , the cross-sections of the plurality of through-holes 21 and 22 may be circular in shape. Referring to Figure 7 , the cross-sections of the plurality of through-holes 21 and 22 may be formed in a substantially elliptical shape having a relatively long axis in a direction parallel to the width direction (x-direction) of the battery cell 10.

[0071] In some examples, the material of the fixing member 20 may be at least one of silicone rubber, polyurethane, or ethylene vinyl acetate (EVA). The present disclosure is not limited thereto, and various synthetic rubbers with high hardness may be applied.

[0072] Referring to Figure 6 and Figure 7 , the fixing member 20 may further include an adhesive member 25 attached to each of the two wide surfaces in contact with the battery cell 10. In some examples, the material of the adhesive member 25 may be acrylic, but the present disclosure is not limited thereto, and materials with various adhesive strengths may be applied. The adhesive strength of the adhesive member 25 may be about 1300 g / 25.4 mm or greater. If the adhesive strength of the adhesive member 25 is less than about 1300 g / 25.4 mm, the interface may separate if the battery pack 1 drops. The thickness of the adhesive member 25 may be about 10% or less compared to the thickness of the fixing member 20 other than the adhesive member 25.

[0073] In addition, compared with the total thickness T of the fixing member 20 including the bonding member 25 max the minimum thickness T of the fixing member 20 min (which is the minimum thickness between one of the plurality of through holes 21 and 22 and the surface of the remaining portion of the fixing member 20 other than the bonding member 25) can be in the range of about 10% to about 30%. For example, if the minimum thickness T of the fixing member 20 min is less than about 10% of the total thickness T of the fixing member 20 max the strength of the fixing member 20 is reduced, so that the force for suppressing movement is reduced. If the minimum thickness T min exceeds about 30% of the total thickness T max the force for absorbing swelling is reduced.

[0074] In some examples, referring to the following equations 1, 2, and 3, the total thickness T of the fixing member 20 max and the minimum thickness T min as well as the minimum diameter D of the through holes 21 and 22 hole are determined based on the thickness BT of the battery cell 10, the thickness AT of the bonding member 25, the set swelling rate SR, and the set compression rate CR. The set swelling rate SR represents the maximum swelling rate value compared with the thickness BT of the battery cell 10, and can be a preset value. The set compression rate CR represents the maximum compression rate of the fixing member 20 at the set swelling rate SR, and can be a preset value.

[0075] For example, the total thickness T of the fixing member 20 max and the minimum thickness T min as well as the minimum diameter D of the through holes 21 and 22 hole can be calculated based on the following equations 1, 2, and 3. AT is the thickness of the bonding member 25.

[0076] Equation 1

[0077] T max =(BT×SR)+{((BT×SR)÷2)×CR+(AT×2)}

[0078] Equation 2

[0079] D hole =(BT×SR)÷2

[0080] Equation 3

[0081] T min ={(T max -(AT×2))-D hole}÷2

[0082] For example, if the thickness BT of the battery cell is about 6 mm, the set bulging rate SR is about 8%, the set compression rate CR is about 50%, and the thickness AT of the bonding member is about 0.05 mm, then the total thickness T of the fixing member 20 max is about 0.7 mm, and the minimum diameter D of the through holes 21 and 22 hole is about 0.24 mm, and the minimum thickness T of the fixing member 20 min is about 0.18 mm.

[0083] In one or more embodiments, the total thickness T of the fixing member 20 max and the minimum thickness T min and the minimum diameter D of the through holes 21 and 22 hole can be calculated based on the thickness BT of the battery cell 10, the thickness AT of the bonding member 25, the set bulging rate SR, and the set compression rate CR. The minimum diameter D of the through holes 21 and 22 hole can be formed in response to the compression rate of the fixing member 20 according to the bulging of the battery cell 10.

[0084] In one or more embodiments, the area of the wide surface of the fixing member 20 can be less than or equal to the area of the surface of the battery cell 10 that contacts the wide surface. The area of the wide surface of the fixing member 20 is formed to be less than or equal to the area of the stacked surface of the battery cell 10 such that if the battery cells 10 are stacked, the battery cells 10 can be attached to be fixed.

[0085] According to one or more embodiments of the present disclosure, for fixing a single cell among the cells in a battery pack, a plurality of through holes (which pass through the fixing member from one side to the other side in a direction parallel to the attachment surface of the single cell) can be formed to ensure the hardness for suppressing the movement of the single cell and ensure the compression force for absorbing the bulging of the single cell, thereby reducing or minimizing the useless space due to the volume (thickness) of the fixing member, and thereby improving the product reliability.

[0086] Aspects of the present disclosure are not limited to the above aspects, and other aspects not mentioned can be clearly understood by those skilled in the art from the description of the present disclosure described below.

[0087] The above description is only for implementing the secondary battery pack according to the present disclosure. Those of ordinary skill in the art to which the present disclosure pertains will understand that the present disclosure is not limited to the above embodiments, and that various modifications can be made without departing from the spirit and scope of the present disclosure defined by the appended claims (including functional equivalents thereof) to the extent that they include the technical spirit of the present disclosure. Although the present disclosure has been described with limited examples and drawings, the present disclosure is not limited thereto, and various modifications and changes are possible by those of ordinary skill in the art to which the present disclosure pertains within the scope of the technical idea of the present disclosure and within the scope of the claims to be described below.

[0088] This application claims the priority and benefit of Korean Patent Application No. 10-2023-0178497, filed with the Korean Intellectual Property Office on December 11, 2023, the entire disclosure of which is incorporated herein by reference.

Claims

1. A battery pack comprising: a battery cell including an electrode assembly in a housing and including one or more electrode tabs; as well as A fixing member is provided between the battery cells to fix the battery cells and defines a through hole passing from one end of the fixing member to the other end of the fixing member. The battery pack according to claim 1 , wherein the through hole has a circular cross-section. 3 . The battery pack according to claim 1 , wherein the through hole has an elliptical cross-section having a major axis parallel to a width direction of the battery cell. 4 . The battery pack according to claim 1 , wherein the fixing member comprises at least one of silicone rubber, polyurethane, or ethylene vinyl acetate. 5 . The battery pack according to claim 1 , wherein a minimum diameter of the through hole corresponds to a compression rate of the fixing member based on swelling of the battery cell. 6 . The battery pack according to claim 1 , wherein the fixing member has a hexahedral shape including four side surfaces and two wide surfaces, the two wide surfaces contacting the battery cells. 7 . The battery pack according to claim 6 , wherein the through hole penetrates from one side surface among the four side surfaces to another side surface opposite thereto among the four side surfaces. 8 . The battery pack according to claim 7 , wherein the through hole is parallel to a longitudinal direction of the battery cell. 9 . The battery pack according to claim 7 , wherein the through hole is parallel to a direction in which the electrode tab protrudes. 10 . The battery pack according to claim 7 , wherein the through hole is perpendicular to a longitudinal direction of the battery cell. The battery pack according to claim 7 , wherein the through holes are side by side. 12 . The battery pack according to claim 6 , wherein the through holes include a first through hole parallel to a longitudinal direction of the battery cell and a second through hole perpendicular to the longitudinal direction of the battery cell. 13 . The battery pack according to claim 12 , wherein the first through hole and the second through hole cross each other. 14 . The battery pack according to claim 6 , wherein an area of ​​one of the two wide surfaces of the fixing member is smaller than or equal to an area of ​​a surface of the battery cell contacting the one of the two wide surfaces. 15 . The battery pack according to claim 6 , wherein the fixing member further comprises an adhesive member at at least one of the two wide surfaces. 16 . The battery pack according to claim 15 , wherein a minimum thickness of the fixing member between a surface of a remaining portion of the fixing member excluding the adhesive member and one of the through holes is 10% to 30% of a maximum thickness of the fixing member between the two wide surfaces. The battery pack according to claim 15 , wherein the adhesive member comprises an acrylic material. 18 . The battery pack according to claim 15 , wherein the adhesive member has an adhesive strength of 1300 g / 25.4 mm or more. 19 . The battery pack according to claim 15 , wherein the adhesive member has a thickness that is 10% or less of a thickness of a remaining portion of the fixing member excluding the adhesive member. 20 . The battery pack according to claim 1 , wherein the battery cells are stacked in a stack type.

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