Battery pack, battery assembly, and vehicle including same

Abstract

A battery pack according to the present invention includes: a battery module; a middle case that is configured to accommodate the battery module and includes a top plate, a bottom plate spaced apart from the top plate so that a battery accommodation space is formed between the bottom plate and the top plate, and a middle wall that connects the top plate with the bottom plate so as to partition the battery accommodation space; and a side case coupled to the top plate and the bottom plate outside the battery accommodation space to cover the side of the battery accommodation space. The middle wall is spaced apart from the battery module to form a flow path through which a fluid may move when the fluid is vented from the battery module.

Description

Battery pack, battery assembly and vehicle including same

[0001] [Cross-reference with related applications]

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0176929, filed December 7, 2023, and Korean Patent Application No. 10-2024-0063450, filed May 14, 2024, the entire contents of which are incorporated herein by reference.

[0003] [Technical Field]

[0004] The present invention relates to a battery pack, a battery assembly, and a vehicle including the same.

[0005] With the technological development and increasing demand for electric vehicles, mobile devices, and other devices, the demand for secondary batteries as an energy source is increasing. Unlike primary batteries, secondary batteries can be recharged and reused after a single use. A secondary battery consists of a cathode and anode. When a metal in the cathode oxidizes, electricity is generated through the movement of electrons released from the metal.

[0006] Secondary batteries can be arranged in multiples to form a battery module. While the voltage generated by each secondary battery is limited, connecting multiple secondary batteries can generate a high voltage. Multiple secondary batteries form a battery module, and the voltage of the secondary batteries within the formed battery module can be controlled to remain constant by a battery management system (BMS). Multiple battery modules are arranged to form a battery pack, and the formed battery pack can include a cooling device or the like to manage the temperature of the battery module.

[0007] A battery pack may be mounted on a device that requires electricity. For example, the battery pack may be mounted on a vehicle. When mounted on a vehicle, the battery pack may be positioned relatively low compared to other components of the vehicle to lower the vehicle's center of gravity, taking into account the weight of the battery pack. Accordingly, the battery pack may be positioned adjacent to a location where a user's feet are placed. A battery pack located at a location where a user's feet are placed may be subject to impact when the user steps on it, and if impact is applied to the battery pack, the battery pack may malfunction.

[0008] The present invention has been devised to solve the above problems, and the object of the present invention is to provide a battery pack including a pack case that is resistant to impact.

[0009] Another object of the present invention is to provide a battery pack that is shock-resistant and allows for smooth fluid discharge when fluid is vented from a secondary battery due to thermal runaway.

[0010] Another object of the present invention is to provide a battery pack that can easily discharge heat generated from a secondary battery in order to prevent thermal runaway of the secondary battery.

[0011] Furthermore, the task of the battery pack of the present invention described above can also be applied to a battery assembly, which is a concept including a battery pack and a battery module.

[0012] The technical problems to be achieved in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

[0013] According to one embodiment of the present invention, a battery assembly comprises: a secondary battery; a middle case configured to accommodate the secondary battery, the middle case including a top plate, a bottom plate spaced apart from the top plate so as to form a battery accommodation space therebetween, and a middle wall connecting the top plate and the bottom plate so as to partition the battery accommodation space; and a side case coupled to the top plate and the bottom plate outside the battery accommodation space to cover a side of the battery accommodation space, wherein the middle wall is spaced apart from the secondary battery so as to form a flow path through which a fluid can move when the fluid is vented from the secondary battery.

[0014] The above side case can be combined with the secondary battery by an adhesive.

[0015] The above side case may include a metal material to enable heat conduction. The thickness of the adhesive may be smaller than the thickness of the side case.

[0016] The thickness of the above adhesive may be 0.3 mm or less.

[0017] The above adhesive may be thermosetting.

[0018] The module case further includes a module case that accommodates the secondary battery and is positioned in the battery accommodation space, and a module hole may be formed in a position corresponding to the secondary battery so that when the fluid is vented from the secondary battery, the fluid can move toward the path.

[0019] The secondary battery has a cylindrical shape, includes a positive electrode protrusion at one end and a negative electrode surface at the other end, and the negative electrode surface and the module case can be bonded to the side case.

[0020] The battery may further include a venting valve that opens to allow the fluid moved along the path to move to the outside based on a pressure difference between the fluid inside the battery receiving space and the outside becoming equal to or greater than a predetermined pressure.

[0021] The venting valve may include a membrane whose permeability changes to allow the fluid to pass based on a pressure difference between the fluid and the outside being greater than or equal to the predetermined pressure.

[0022] The above venting valve can be positioned in the direction of gravity.

[0023] The above battery receiving space is partitioned into a first battery receiving space and a second battery receiving space by the middle wall, and the venting valve may include a first venting valve corresponding to the first battery receiving space and a second venting valve corresponding to the second battery receiving space.

[0024] The above middle case can be formed integrally. The above side case can be connected to the top plate and the bottom plate by bolts.

[0025] The cover case may further include a cover case coupled to the middle case to cover the other side of the battery receiving space.

[0026] According to one embodiment of the present invention, a vehicle includes a vehicle frame and a battery assembly forming at least a portion of a bottom of the vehicle frame, wherein the battery pack includes a battery module, a middle case configured to accommodate the battery module, the middle case including a top plate, a bottom plate spaced apart from the top plate so as to form a battery accommodation space therebetween, and a middle wall connecting the top plate and the bottom plate so as to partition the battery accommodation space, and a side case coupled to the top plate and the bottom plate outside the battery accommodation space to cover a side of the battery accommodation space, wherein the middle wall is spaced apart from the battery module so as to form a flow path through which a fluid can move when the fluid is vented from the battery module.

[0027] The above side case can be combined with the battery module by an adhesive.

[0028] The above side case may include a metal material to enable heat conduction.

[0029] The battery may further include a venting valve that opens to allow the fluid moved along the path to move to the outside based on a pressure difference between the fluid inside the battery receiving space and the outside becoming equal to or greater than a predetermined pressure.

[0030] A battery pack according to one embodiment of the present invention comprises a battery module including a secondary battery, a middle case configured to accommodate the battery module, the middle case including a top plate, a bottom plate spaced apart from the top plate so as to form a battery accommodation space therebetween, and a middle wall connecting the top plate and the bottom plate so as to partition the battery accommodation space, and a side case coupled to the top plate and the bottom plate outside the battery accommodation space to cover a side of the battery accommodation space, and coupled to the secondary battery by an adhesive.

[0031] The battery pack according to the present invention can provide a pack case that is resistant to impact by including a middle wall connecting a top plate and a bottom plate.

[0032] In the battery pack according to the present invention, the middle wall and the battery module are spaced apart so that the fluid can be vented, so that when the fluid is vented from the secondary battery due to thermal runaway, the fluid can be discharged smoothly.

[0033] The battery pack according to the present invention can prevent thermal runaway of the secondary battery by easily discharging heat generated from the secondary battery by bonding the secondary battery and the side case with an adhesive.

[0034] Furthermore, the effects of the battery pack of the present invention described above can also be applied to a battery assembly, which is a concept including a battery pack and a battery module.

[0035] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0036] FIG. 1 is a side view illustrating a vehicle equipped with a battery pack according to a first embodiment of the present invention.

[0037] Figure 2 is a cross-sectional view of a conventional battery pack.

[0038] Figure 3 is a perspective view of the battery pack illustrated in Figure 1.

[0039] Figure 4 is an exploded view of the battery pack illustrated in Figure 3.

[0040] FIG. 5 is a cross-sectional view showing the battery pack shown in FIG. 3 cut along line V-V'.

[0041] Figure 6 is a conceptual diagram showing the movement of fluid in the cross-sectional view shown in Figure 5.

[0042] Figure 7 is a conceptual diagram showing the movement of heat in the cross-sectional view shown in Figure 5.

[0043] Figure 8 is a cross-sectional view of a battery pack according to the second embodiment.

[0044] Figure 9 is a cross-sectional view of a battery pack according to the third embodiment.

[0045] Fig. 10 is a cross-sectional view of a battery pack according to the fourth embodiment.

[0046] Fig. 11 is a cross-sectional view of a battery pack according to the fifth embodiment.

[0047] Fig. 12 is a cross-sectional view of a battery pack according to the sixth embodiment.

[0048] Hereinafter, with reference to the attached drawings, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

[0049] In order to clearly explain the present invention, a detailed description of a part that is irrelevant to the description or a related known technology that may unnecessarily obscure the gist of the present invention has been omitted, and when adding reference signs to components of each drawing in this specification, the same or similar reference signs are attached to the same or similar components throughout the specification.

[0050] In addition, terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as 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 to explain his or her own invention in the best way.

[0051] It should be understood that the various embodiments and terms used in this document are not intended to limit the technical features described in this document to specific embodiments, but rather to include various modifications, equivalents, or substitutes of the embodiments.

[0052] In connection with the description of the drawings, similar reference numerals may be used for similar or related components.

[0053] The singular form of a noun corresponding to an item may include one or more of said items, unless the relevant context clearly indicates otherwise.

[0054] In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof.

[0055] The term “and / or” includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0056] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish one component from another and do not qualify the components in any other respect (e.g., importance or order).

[0057] When a component (e.g., a first component) is referred to as being "coupled" or "connected" to another component (e.g., a second component), with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0058] The terms “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in this document, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0059] When a component is said to be “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only cases where the components are directly connected, coupled, supported, or in contact, but also cases where the components are indirectly connected, coupled, supported, or in contact through a third component.

[0060] When we say that a component is "on" another component, this includes not only cases where the component is in contact with the other component, but also cases where there is another component between the two components.

[0061] Meanwhile, the terms “upper and lower directions,” “lower side,” and “front and rear directions” used in the following description are defined based on the drawings, and the shape and position of each component are not limited by these terms.

[0062] Hereinafter, embodiments according to the present invention will be described in detail with reference to the attached drawings.

[0063] FIG. 1 is a side view illustrating a vehicle (V) equipped with a battery pack (BP) according to a first embodiment of the present invention.

[0064] Referring to Fig. 1, a vehicle (V) according to a first embodiment of the present invention will be described.

[0065] A vehicle (V) requiring electrical energy may be provided. Here, the vehicle (V) refers to a moving device, and may be a motorcycle as illustrated in Fig. 1, or an automobile. However, for convenience of explanation, the vehicle (V) will be assumed to be a motorcycle as illustrated in Fig. 1.

[0066] A vehicle (V) may include a battery pack (BP) configured to generate battery energy. The battery pack (BP) may have a predetermined weight, and may be mounted on the lower portion of the vehicle (V) to ensure that the battery pack (BP) having the weight is stably mounted. Furthermore, since the battery pack (BP) is mounted on the lower portion of the vehicle (V), the battery pack (BP) may be adjacent to a position where a user's feet are placed. While using the vehicle (V), the user may kick the battery pack (BP) with his or her feet. Accordingly, the battery pack (BP) may be subjected to shock. When the battery pack (BP) is subjected to shock, the shock may also be transmitted to the secondary battery (B) included in the battery pack (BP), which may induce a side reaction in the secondary battery (B), and thus, a problem of thermal runaway of the secondary battery (B) may occur. To prevent this, the battery pack (BP) may be positioned within the lower frame of the vehicle (V), unlike as illustrated in FIG. 1. However, a separate configuration or structure may be required to ensure sufficient rigidity of the battery pack (BP) or to prevent the battery pack (BP) from being damaged. Since providing a separate configuration may entail an increase in production time or cost, the battery pack (BP) needs to be made strong without adding a separate configuration. Furthermore, when the battery pack (BP) serves as a footrest of the vehicle (V), as illustrated in Fig. 1, the rigidity of the battery pack (BP) needs to be further increased. That is, when the battery pack (BP) forms at least a portion of the vehicle frame floor of the vehicle (V), a battery pack (BP) with increased rigidity may be required.

[0067] Additionally, the battery assembly (BA) may include a battery pack (BP) and a battery module (BM) described below. The battery assembly (BA) may include a secondary battery (B) and may be configured to include components necessary for proper operation of the secondary battery (B). The secondary battery (B) may be provided by forming a battery module (BM), or may be provided in the form of a battery pack (BP) including a plurality of battery modules (BM). Furthermore, the battery pack (BP) may be provided without forming a battery module (BM). Although providing the secondary battery (B) by first forming a module unit may be structurally more stable, it may require longer production time and higher manufacturing costs because it includes more components. Therefore, a person who uses or produces the secondary battery (B) may provide the secondary battery (B) in an appropriate form as needed. The battery assembly (BA) may be understood as a general term for the concept of providing a secondary battery (B) in this form. Accordingly, what is described as a battery pack (BP) hereinafter may be understood as a battery assembly (BA), and if the battery pack (BP) does not include a battery module (BP) and is formed directly from a secondary battery (B), the battery module (BP) in the following description may be understood as a secondary battery (B).

[0068] Figure 2 is a cross-sectional view of a conventional battery pack (BP-0).

[0069] Referring to Fig. 2, a conventional battery pack (BP-0) is described.

[0070] A battery pack (BP-0) may include a pack case (PC-0) that accommodates a battery module (BM). The pack case (PC-0) of a conventional battery pack (BP-0) is formed of two parts and assembled together. The pack case (PC-0) is formed of two parts, each of which constitutes an upper side and a lower side, and a battery module (BM) may be accommodated between the parts of each pack case (PC-0). If an impact is applied to the upper side of the pack case (PC-0), deformation may occur in the pack case (PC-0), as illustrated in FIG. 2. Since the edge of the upper side of the pack case (PC-0) is in contact with the lower side of the pack case (PC-0), deformation of the pack case (PC-0) may be prevented when an impact is applied to the edge of the pack case (PC-0). However, the central portion of the pack case (PC-0), which is located on the inner side of the edge of the upper portion of the pack case (PC-0), is not supported by the lower portion of the pack case (PC-0), and therefore has no portion that supports impact, and therefore, it is difficult to resist the impact applied, and deformation may easily occur. The present invention can improve the above-mentioned problem.

[0071] Furthermore, the conventional pack case (PC-0) is not structured to prepare for a thermal runaway phenomenon that occurs due to a side reaction in the secondary battery (B). Since the secondary battery (B) may experience a side reaction due to impact, etc., the present invention may require a structure that prepares for such a situation.

[0072] Fig. 3 is a perspective view of the battery pack (BP) illustrated in Fig. 1. Fig. 4 is an exploded view of the battery pack (BP) illustrated in Fig. 3. Fig. 5 is a cross-sectional view of the battery pack (BP) illustrated in Fig. 3 taken along line V-V'.

[0073] Referring to FIGS. 3 to 5, a battery pack (BP) according to a first embodiment of the present invention will be described.

[0074] As illustrated in FIG. 4, the battery pack (BP) may include a secondary battery (B) configured to produce electricity.

[0075] A secondary battery (B) can generate electricity. The secondary battery (B) may include an electrode assembly (not shown), and the electrode assembly may include an electrode (not shown) including a current collector (not shown) made of a metallic material and a slurry (not shown) applied to the current collector. The electrodes may be provided in plurality, and the electrode assembly may include a plurality of separators (not shown) positioned between the plurality of electrodes. In this case, the electrodes generate electricity, and the separators may be provided to prevent contact between the slurries of each of the plurality of electrodes. The electrode assembly may include electrode tabs (not shown) extending from the current collector. Electrode leads (not shown) connected to the plurality of electrode tabs extending from the plurality of current collectors may be provided. Accordingly, electricity generated from the electrodes may move toward the electrode leads through the electrode tabs.

[0076] The secondary battery (B) may include a battery case configured to accommodate an electrode assembly. For example, the battery case may be pouch-shaped, cylindrical, or square. For convenience of explanation, the present disclosure assumes that the battery case is cylindrical, as illustrated in FIG. 4. However, the present disclosure is not limited thereto.

[0077] The secondary battery (B) may include a positive electrode protrusion (610) having a positive electrode and a negative electrode surface (620) having a negative electrode. However, the positive electrode and the negative electrode may have electrical properties that are reversed, and in the present disclosure, for the convenience of explanation, it is assumed and described that the positive electrode protrusion (610) has a positive electrode and the negative electrode surface (620) has a negative electrode.

[0078] A plurality of secondary batteries (B) may be provided to form a battery module (BM). The battery module (BM) may be electrically connected to a battery management system (BMS), and the battery management system may control a plurality of secondary batteries (B) so that the voltages of the plurality of secondary batteries (B) remain within a preset range.

[0079] The battery module (BM) may include a module case (700) configured to accommodate a plurality of secondary batteries (B). For example, the plurality of secondary batteries (B) may be arranged in a matrix, as illustrated in FIG. 4, and the module case (700) may have an approximately rectangular parallelepiped shape to accommodate the plurality of secondary batteries (B) arranged in a matrix.

[0080] An opening may be formed on one side of the module case (700). Through the opening formed in the module case (700), the secondary battery (B) may be accommodated inside the module case (700). In other words, through the opening formed in the module case (700), the negative electrode side (620) of the secondary battery (B) may be exposed to the outside of the battery module (BM). The opening formed in the module case (700) may face the side case (200) described below.

[0081] The module case (700) may have a module hole (700H) formed at a position corresponding to the positive electrode protrusion (610) of the secondary battery (B). Through the module hole (700H), the positive electrode protrusion (610) of each of the plurality of secondary batteries (B) and a bus bar (not shown) may be connected. The bus bar may be configured to be exposed to the outside of the battery module (BM) so as to enable electrical connection between adjacent battery modules (BM). Furthermore, as described below, the module hole (700H) may serve as a passage through which a fluid, such as a gas generated by a side reaction, may escape the module case (700) when a side reaction occurs in the secondary battery (B).

[0082] As illustrated in FIG. 3, the battery pack (BP) may include a pack case (PC) configured to accommodate a battery module (BM). In other words, the pack case (PC) may have a battery accommodation space (130S) formed therein in which the battery module (BM) is accommodated. For example, the pack case (PC) may have an approximately rectangular parallelepiped shape to correspond to the shape of the battery module (BM). Considering the difficulty in forming the pack case (PC) as a single body in terms of process and the difficulty in accommodating the battery module (BM) inside when formed as a single body, the pack case (PC) may be formed as a plurality of parts.

[0083] A middle case (100) covering the upper and lower sides of a pack case (PC) may be included. That is, the middle case (100) is provided to accommodate a battery module (BM), and may include a top plate (110) and a bottom plate (120) spaced apart from the top plate (110) so that a battery accommodation space (130S) is formed between the top plate (110). Furthermore, the middle case (100) may further include a middle wall (130) connecting the top plate (110) and the bottom plate (120) so as to partition the battery accommodation space (130S).

[0084] The middle wall (130) may be positioned in the middle of the width direction of the top plate (110) and the bottom plate (120), as illustrated in FIG. 5, but is not limited thereto. Furthermore, the middle wall (130) may extend in a direction parallel to the length direction of the top plate (110) and the bottom plate (120), as illustrated in FIG. 4, but is not limited thereto. The middle wall (130) may extend at a predetermined angle with the length direction of the top plate (110) and the bottom plate (120), and further, may extend in the width direction of the top plate (110) and the bottom plate (120). Additionally, the middle wall (130) may not be configured to extend in only one direction, but may extend to form various shapes. However, for convenience of explanation, it is assumed and explained that the middle wall (130) is located at the center of the width direction of the top plate (110) and the bottom plate (120) and extends only in the direction parallel to the length direction of the top plate (110) and the bottom plate (120). That is, the middle case (100) may have a shape such that the cross-section is a rotated "H". The battery receiving space (130S) may be partitioned into a first battery receiving space (130Sa) and a second battery receiving space (130Sb) by the middle wall (130), as illustrated in FIG. 4. The first battery receiving space (130Sa) and the second battery receiving space (130Sb) formed by the middle case (100) may be located on the left and right sides of the middle wall (130), respectively. In this case, the right side of the first battery receiving space (130Sa) may be covered by the middle wall (130), and the upper and lower sides may be covered by the top plate (110) and the bottom plate (120), respectively. In this case, the left side of the first battery receiving space (130Sa) and the right side of the second battery receiving space (130Sb) may be open to the middle case (100). The middle wall (130) will be further described after the brief description of the battery pack (BP) is completed.

[0085] Additionally, the middle case (100) may be formed integrally. This is because forming it integrally may be more suitable for improving rigidity.

[0086] The battery pack (BP) may include a side case (200) coupled to the top plate (110) and the bottom plate (120) on the outside of the battery receiving space (130S) to cover the side of the battery receiving space (130S). The side cases (200) may be provided in multiple numbers to cover the left side of the first battery receiving space (130Sa) and the right side of the second battery receiving space (130Sb), respectively. In other words, the side cases (200) may have shapes corresponding to the left and right openings formed in the middle case (100), respectively. The side cases (200) may have a plate shape extending in the left and right directions, as illustrated in FIG. 4. Furthermore, the side cases (200) may cover the opening formed in the battery module (BM). As described above, the module case (700) may be formed with an opening for receiving the secondary battery (B). The side case (200) can cover the opening formed in the module case (700) to prevent the secondary battery (B) from moving to the outside of the module case (700).

[0087] The side case (200) can be coupled to the middle case (100). More specifically, the side case (200) can be coupled to the top plate (110) and the bottom plate (120) by bolts (500). Accordingly, the side case (200) and the middle case (100) can be strongly coupled. Furthermore, the side case (200) can also be coupled to the cover case (300) described later by bolts (500). When the side case (200) is viewed from the side, it has a rectangular shape, and the bolts (500) need to be fastened along the rectangular border so that the side case (200) can be strongly coupled to the adjacent configuration. The top plate (110) and the bottom plate (120) can be provided to correspond to the upper and lower sides of the rectangle, and the cover cases (300) positioned on both sides can be provided to correspond to the left and right sides of the rectangle. In other words, the top plate (110), the bottom plate (120) and / or the cover case (300) may extend to the cover case (300) so as to be coupled with the side case (200). That is, the top plate (110), the bottom plate (120) and / or the cover case (300) may extend in the left-right direction to the cover case (300). At this time, the width of the module case (700) may be smaller than or equal to the width of the battery receiving space (130S) so as to prevent the side case (200) and the top plate (110) and / or the bottom plate (120) from being coupled by the module case (700).

[0088] The battery pack (BP) may further include a cover case (300) coupled with the middle case (100) to cover the other side of the battery receiving space (130S). More specifically, the cover case (300) may be positioned at the front and / or rear of the middle case (100) to cover the front and / or rear of the battery receiving space (130S). Accordingly, the battery module (BM) may be covered in all directions by being covered by the middle wall (130) and the side case (200) on the left and right sides, by being covered by the top plate (110) and the bottom plate (120) on the upper and lower sides, and by being covered by the cover case (300) on the front and rear.

[0089] At this time, the cover case (300) may include a connecting portion (310) that protrudes toward the opposite side toward the battery receiving space (130S). The connecting portion (310) may be configured to be coupled with other components of the vehicle (V).

[0090] When the battery pack (BP) is accommodated in the vehicle (V) lower frame, the vehicle (V) lower frame can support the battery pack (BP), but when the battery pack (BP) serves as a foothold, the battery pack (BP) needs to be connected to a surrounding structure. The connecting portion (310) can be a structure for connecting the battery pack (BP) to an adjacent structure of the battery pack (BP).

[0091] The configuration of the battery pack (BP) has been described above, and it has been described that a shock-resistant pack case (PC) can be prepared according to the present invention. The secondary battery (B) may experience side reactions in various cases. Side reactions may refer to reactions of the secondary battery (B) that were not originally intended. Due to the side reactions, the temperature of the secondary battery (B) may increase, which may lead to ignition. The ignited secondary battery (B) may induce ignition of adjacent secondary batteries (B), and the entire battery pack (BP) may ignite, potentially leading to ignition of the vehicle (V). This may threaten the safety of the user, and therefore, it is necessary to prevent this. Furthermore, when the temperature of the secondary battery (B) increases, the electrolyte may evaporate. The evaporated electrolyte may become a gas, thereby increasing the pressure inside the secondary battery (B), which may ultimately damage the battery case and be released outside the secondary battery (B). The evaporated electrolyte may be considered a fluid, as the electrolyte in a liquid state may be mixed with the electrolyte in a gaseous state. The fluid generated from the secondary battery (B) needs to be discharged outside the pack case (PC) because there is a risk of damaging the pack case (PC).

[0092] Below, a structure for solving the above problem of the present invention is described.

[0093] Figure 6 is a conceptual diagram showing the movement of fluid in the cross-sectional view shown in Figure 5.

[0094] Referring to FIG. 6, another function of the battery pack (BP) according to the first embodiment of the present invention will be described.

[0095] As illustrated in FIG. 6, the middle wall (130) of the pack case (PC) may be spaced apart from the battery module (BM) to form a flow path through which the fluid can move when the fluid is vented from the battery module (BM). If the middle wall (130) comes into contact with the battery module (BM), it may be difficult for the fluid generated in the battery module (BM) to move. The fluid that cannot move may ultimately increase the pressure of the pack case (PC) and may even damage the pack case (PC). In this case, the flow path may mean a space extending along the middle wall (130). With reference to FIG. 6, the fluid generated from the secondary battery (B) located on the upper side may follow the flow path relatively long, and the fluid generated from the secondary battery (B) located on the lower side may follow the flow path relatively short.

[0096] As described above, the module case (700) may have a module hole (700H) formed at a location corresponding to the secondary battery (B) so that the fluid can move toward the flow path when the fluid is vented from the secondary battery (B). If the module hole (700H) is not formed, the fluid generated from the secondary battery (B) may not be able to escape the battery module (BM), thereby increasing the pressure inside the module case (700), which may ultimately damage the module case (700). Alternatively, the fluid may move while damaging the adhesive (210) positioned between the module case (700) and the side case (200) described below.

[0097] At this time, the battery pack (BP) may further include a venting valve (400) that opens to allow the fluid moved along the path to move to the outside based on the pressure difference between the fluid inside the battery receiving space (130S) and the outside becoming a predetermined pressure or more. The fluid moved along the path may flow out of the battery pack (BP) along the venting valve (400). The venting valve (400) may not be constantly open, but may open in response to the pressure of the battery pack (BP) rising above a predetermined pressure. The predetermined pressure to which the venting valve (400) reacts may be a value corresponding to the pressure increase within the battery pack (BP) that increases when venting of the fluid occurs due to a side reaction in one of the secondary batteries (B).

[0098] The venting valve (400) may include a membrane whose permeability changes to allow fluid to pass through based on a pressure difference between the fluid and the outside being greater than a predetermined pressure. However, the venting valve (400) is not limited thereto, and may also be an umbrella valve whose opening and / or closing are structurally determined by a pressure difference.

[0099] The venting valve (400) may be positioned adjacent to the flow path. This is because moving the fluid directly from the flow path to the venting valve (400) reduces frictional losses compared to moving the fluid to another location.

[0100] The venting valve (400) may be positioned in the direction of gravity. If the battery pack (BP) is mounted on the lower portion of the vehicle (V), and the venting valve (400) is positioned on the upper portion, the vented fluid may be directed toward the user. To prevent this, the venting valve (400) may be positioned in the direction of gravity. If the fluid is moved in the direction of gravity, the fluid may be moved toward the lower portion of the vehicle (V).

[0101] In other words, the fluid can be moved out of the battery pack (BP) through the venting valve (400) along the flow path. By this fluid flow, the fluid can be prevented from diffusing into the battery receiving space (130S). If the fluid were to diffuse into the battery receiving space (130S), it could affect other secondary batteries (B), which could cause the other secondary batteries (B) to fail.

[0102] As mentioned above, the battery receiving space (130S) may be partitioned into a first battery receiving space (130Sa) and a second battery receiving space (130Sb) by the middle wall (130). The venting valve (400) may include a first venting valve (400a) corresponding to the first battery receiving space (130Sa) and a second venting valve (400b) corresponding to the second battery receiving space (130Sb). Since the battery receiving space (130S) may be partitioned by the middle wall (130), a venting valve (400) corresponding to each battery receiving space (130S) may be provided in order to vent the fluid in each battery receiving space (130S). However, as illustrated in FIG. 6, the present disclosure includes not only one venting valve (400) corresponding to each battery receiving space (130S), but also a plurality of venting valves corresponding to each battery receiving space (130S).

[0103] At this time, additionally, the top plate (110) and / or the bottom plate (120) may be in contact with the battery module (BM) differently from that illustrated in FIG. 6. In this case, the empty space may be minimized to increase the energy density per unit volume. However, the top plate (110) and / or the bottom plate (120) may be spaced apart from the battery module (BM) as illustrated in FIG. 6. In this case, a space may be provided to prevent a sudden increase in pressure in order to prevent the battery pack (BP) from being damaged by rapid venting of fluid due to a side reaction of the secondary battery (B).

[0104] Figure 7 is a conceptual diagram showing the movement of heat in the cross-sectional view shown in Figure 5.

[0105] Referring to FIG. 7, another function of the battery pack (BP) according to the first embodiment of the present invention will be described.

[0106] The battery module (BM) includes a secondary battery (B), and the side case (200) can be coupled to the secondary battery (B) by an adhesive (210). That is, the secondary battery (B) can be directly coupled to the side case (200) by the adhesive (210). The secondary battery (B) can be in contact with the side case (200). Accordingly, heat generated in the secondary battery (B) can be directly transferred to the side case (200). In particular, when the secondary battery (B) is about to undergo thermal runaway, the heat generated in the secondary battery (B) can be immediately released through the side case (200), so that the heating time can be delayed. Alternatively, the secondary battery (B) can be prevented from reaching a temperature at which a side reaction occurs. Heat dissipation can mean that heat management of the secondary battery (B) becomes easier.

[0107] As mentioned above, the secondary battery (B) may have a cylindrical shape and include a positive electrode protrusion (610) at one end and a negative electrode surface (620) at the other end. At this time, the negative electrode surface (620) and the module case (700) may be bonded to the side case (200). Since bonding the negative electrode surface (620) to the side case (200) rather than having the positive electrode protrusion (610) protrude from the side case (200) allows a wider area of ​​the secondary battery (B) to be adjacent to the side case (200), it may be more effective in dissipating heat.

[0108] The side case (200) may include a metal material to enable heat conduction.

[0109] The thickness of the adhesive (210) may be smaller than the thickness of the side case (200). Since heat transfer speed increases as the distance to transfer heat decreases, the thickness of the adhesive (210) may need to be thin.

[0110] The thickness of the adhesive (210) may be 0.3 mm or less. If the thickness of the adhesive (210) is too thin, it may be difficult to attach the secondary battery (B) to the side case (200). Therefore, the adhesive (210) needs to be thick enough to attach the secondary battery (B) to the side case (200) without being too thick.

[0111] The adhesive (210) may be thermosetting. The secondary battery (B) may generate heat while generating electricity. If the adhesive (210) is thermosetting, it may be curable so as to continuously bond the side case (200) and the secondary battery (B) while the secondary battery (B) is in operation.

[0112] Below, embodiments different from the first embodiment are described. Commonalities with the first embodiment will be omitted as much as possible, and the other embodiments will be described focusing on differences. In other words, it should be clear that any details not described in the other embodiments can be supplemented by the first embodiment.

[0113] Second Example

[0114] Figure 8 is a cross-sectional view of a battery pack (BP) according to a second embodiment of the present invention.

[0115] Referring to FIG. 8, a middle wall (130) according to a second embodiment of the present invention is described.

[0116] The second embodiment differs from the first embodiment in that the shape of the middle wall (130) is different.

[0117] The middle wall (130) may have a thickness that increases toward the direction of gravity. The side of the middle wall (130) with a thicker thickness has a stronger bonding force and can withstand impact relatively better. Furthermore, since the venting valve (400) may be positioned closer to the side of the middle wall (130) in the direction of gravity, the cross-sectional area of ​​the flow path on the side adjacent to the venting valve (400) may be reduced, thereby increasing the velocity of the fluid on the side adjacent to the venting valve (400).

[0118] Third Example

[0119] Figure 9 is a cross-sectional view of a battery pack (BP) according to a third embodiment of the present invention.

[0120] Referring to FIG. 9, a middle wall (130-2) according to a third embodiment of the present invention is described.

[0121] The third embodiment differs from the first embodiment in that the number of middle walls (130-2) is different.

[0122] The middle wall (130-2) may be provided in multiples. As illustrated in Fig. 9, two middle walls (130-2) may be provided. The two middle walls (130-2) may extend in parallel directions to each other.

[0123] Example 4

[0124] Fig. 10 is a cross-sectional view of a battery pack (BP) according to a fourth embodiment of the present invention.

[0125] Referring to FIG. 10, a middle wall (130-3) according to a fourth embodiment of the present invention is described.

[0126] The fourth embodiment differs from the first embodiment in that the shape of the middle wall (130-3) is different.

[0127] The middle wall (130-3) may have a truss structure. A middle wall (130-3) with a truss structure can be lightweight while maintaining sufficient rigidity. Furthermore, a middle wall (130-3) with a truss structure can reduce production costs by using less material.

[0128] Example 5

[0129] Fig. 11 is a cross-sectional view of a battery pack (BP) according to a fifth embodiment of the present invention.

[0130] Referring to FIG. 11, a venting valve (400-4) according to a fifth embodiment of the present invention is described.

[0131] The fifth embodiment differs from the first embodiment in that the position of the venting valve (400-4) is different.

[0132] The venting valve (400-4) may be positioned on the side opposite to the direction of gravity with respect to the secondary battery (B). Furthermore, the venting valve (400-4) may be mounted on the side case (200). In this case, the direction of flow may be different from that of the first embodiment. Even though the fluid moves upward, since the venting valve (400-4) is mounted on the side case (200), the fluid exiting the venting valve (400-4) is discharged toward the left or right rather than upward, and thus the fluid may not be directed toward the user.

[0133] Example 6

[0134] Fig. 12 is a cross-sectional view of a battery pack (BP) according to a sixth embodiment of the present invention.

[0135] Referring to FIG. 12, a battery pack (BP) according to a sixth embodiment of the present invention is described.

[0136] The sixth embodiment differs from the fifth embodiment in that the type of secondary battery (B-5) is different.

[0137] The secondary battery (B-5) may be pouch-type. The pouch-type secondary battery (B-5) may be positioned so that the foldable portion of the side portion faces the middle wall (130), and the flat portion located on the opposite side of the foldable portion is in contact with the side case (200). Even in the case of the pouch-type secondary battery (B-5), since the seal of the foldable portion of the side portion is likely to be released earlier than other portions, when a side reaction occurs in the secondary battery (B-5), the fluid vented from the secondary battery (B-5) may be discharged into the flow path through the foldable portion of the side portion.

[0138] Unless explicitly stated otherwise, the embodiments described above may be combined with other embodiments. Alternatively, combinations between embodiments may be considered possible, unless one embodiment is explicitly restricted from being combined with another embodiment. Combinations of one embodiment with another embodiment are deemed to be disclosed in this document.

[0139] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and various embodiments are possible within the scope equivalent to the technical idea of ​​the present invention and the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0140] [Explanation of symbols]

[0141] V: Vehicle

[0142] BP: Battery Pack

[0143] PC: Pack Case

[0144] 100: Middle case

[0145] 110: Top plate

[0146] 120: Bottom plate

[0147] 130: Middle Wall

[0148] 130S: Battery compartment

[0149] 130Sa: 1st battery storage space

[0150] 130Sb: Second battery storage space

[0151] 200: Side case

[0152] 210: Adhesive

[0153] 300: Cover Case

[0154] 310: Connector

[0155] 400: Venting valve

[0156] 400a: 1st venting valve

[0157] 400b: Second venting valve

[0158] 500: Volt

[0159] B: Secondary battery

[0160] 610: Bipolar protrusion

[0161] 620: Negative side

[0162] BM: Battery module

[0163] 700: Modular Case

[0164] 700H: Module Hall

Claims

1. Secondary battery; A middle case configured to accommodate the secondary battery, comprising: a top plate; a bottom plate spaced apart from the top plate so as to form a battery accommodation space therebetween; and a middle wall connecting the top plate and the bottom plate so as to partition the battery accommodation space; and In order to cover the side of the battery receiving space, a side case is included that is coupled with the top plate and the bottom plate on the outside of the battery receiving space, The above middle wall is a battery assembly spaced apart from the secondary battery so as to form a flow path through which the fluid can move when the fluid is vented from the secondary battery.

2. In paragraph 1, The above side case is a battery assembly joined to the secondary battery by an adhesive.

3. In paragraph 1, The above side case is a battery assembly including a metal material to enable heat conduction.

4. In paragraph 2, A battery assembly wherein the thickness of the adhesive is smaller than the thickness of the side case.

5. In paragraph 2, A battery assembly wherein the thickness of the adhesive is 0.3 mm or less.

6. In paragraph 2, The above adhesive is a battery assembly having thermosetting properties.

7. In paragraph 2, Further comprising a module case that accommodates the secondary battery and is positioned in the battery accommodation space, The above module case is a battery assembly in which a module hole is formed at a position corresponding to the secondary battery so that the fluid can move toward the path when the fluid is vented from the secondary battery.

8. In paragraph 7, The above secondary battery has a cylindrical shape and includes a positive electrode protrusion at one end and a negative electrode surface at the other end, A battery assembly in which the negative electrode surface and the module case are bonded to the side case.

9. In paragraph 1, A battery assembly further comprising a venting valve that opens to allow the fluid moved along the path to move to the outside based on a pressure difference between the fluid within the battery receiving space and the outside becoming equal to or greater than a predetermined pressure.

10. In paragraph 9, The venting valve is a battery assembly including a membrane whose permeability changes to allow the fluid to pass based on a pressure difference between the fluid and the outside being greater than or equal to a predetermined pressure.

11. In paragraph 9, The above venting valve is a battery assembly positioned in the direction of gravity.

12. In paragraph 9, The above battery receiving space is divided into a first battery receiving space and a second battery receiving space by the middle wall, The above venting valve, A first venting valve corresponding to the first battery receiving space; and A battery assembly comprising a second venting valve corresponding to the second battery receiving space.

13. In paragraph 1, The above middle case is a battery assembly formed integrally.

14. In paragraph 1, The above side case is a battery assembly connected to the top plate and the bottom plate by bolts.

15. In paragraph 1, A battery assembly further comprising a cover case coupled to the middle case to cover the other side of the battery receiving space.

16. Vehicle frame; and comprising a battery assembly forming at least a portion of the bottom of the vehicle frame; The above battery pack, battery module; A middle case configured to accommodate the battery module, comprising: a top plate; a bottom plate spaced apart from the top plate so as to form a battery accommodation space therebetween; and a middle wall connecting the top plate and the bottom plate so as to partition the battery accommodation space; and In order to cover the side of the battery receiving space, a side case is included that is coupled with the top plate and the bottom plate on the outside of the battery receiving space, The above middle wall is a vehicle spaced apart from the battery module so as to form a flow path through which the fluid can move when the fluid is vented from the battery module.

17. In paragraph 16, A vehicle in which the above side case is joined to the above battery module by an adhesive.

18. In paragraph 16, A vehicle in which the above side case includes a metal material capable of conducting heat.

19. In Article 16, A vehicle further comprising a venting valve that opens to allow the fluid moved along the path to move to the outside based on a pressure difference between the fluid within the battery receiving space and the outside becoming equal to or greater than a predetermined pressure.

20. Battery module including a secondary battery; A middle case configured to accommodate the battery module, comprising: a top plate; a bottom plate spaced apart from the top plate so as to form a battery accommodation space therebetween; and a middle wall connecting the top plate and the bottom plate so as to partition the battery accommodation space; and A battery pack including a side case coupled with the top plate and the bottom plate on the outside of the battery accommodation space to cover the side of the battery accommodation space and coupled with the secondary battery by an adhesive.

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