KR20240161501A - Battery pack and device including the same - Google Patents

Abstract

According to one embodiment of the present invention, a battery pack comprises: at least one battery module including a battery cell stack including a plurality of battery cells and a module frame accommodating the battery cell stack; a pack frame on which the at least one battery module is mounted; and at least one venting plate positioned between a pack bottom portion, which is a bottom surface of the pack frame, and the at least one battery module, wherein at least one lower venting hole is formed at a lower portion of the module frame, and the venting plate includes at least one venting mesh portion formed at a position facing each of the at least one lower venting hole.

Description

BATTERY PACK AND DEVICE INCLUDING THE SAME

The present invention relates to a battery pack and a device including the same, and more particularly, to a battery pack having improved cooling performance and improved venting performance through lower and/or upper venting, and a device including the same.

Secondary batteries, which have high applicability according to product group and electrical characteristics such as high energy density, are widely used in portable devices as well as electric or hybrid vehicles driven by electric power sources, and power storage devices. These secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency enhancement, not only because they can drastically reduce the use of fossil fuels, but also because they do not generate any by-products from energy use.

Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are receiving attention due to their advantages such as the fact that they have almost no memory effect compared to nickel-based secondary batteries, can be freely charged and discharged, have a very low self-discharge rate, and have high energy density.

In general, lithium secondary batteries can be classified into cylindrical or square secondary batteries in which the electrode assembly is built into a metal can, and pouch-type secondary batteries in which the electrode assembly is built into a pouch of an aluminum laminate sheet, depending on the shape of the outer packaging material.

Recently, as the need for a large-capacity secondary battery structure has increased, including the use of secondary batteries as an energy storage source, the demand for a battery pack with a medium- to large-sized module structure that collects a plurality of secondary batteries connected in series or parallel is increasing. Such a battery module improves the capacity and output by forming a battery cell stack by connecting a plurality of battery cells in series or parallel to each other. In addition, a plurality of battery modules can be mounted together with various control and protection systems, such as a BMS (Battery Management System) and a cooling system, to form a battery pack.

Since a battery pack is composed of a structure in which multiple battery modules are combined, if some of the battery modules experience overvoltage, overcurrent, or overheating, the safety and operating efficiency of the battery pack may become a problem. In particular, as the capacity of battery packs is gradually increasing to improve driving distance, and as the internal energy of the pack is also increasing accordingly, it is necessary to design a structure that satisfies the strengthened safety standards and ensures the safety of vehicles and drivers.

In relation to this, in order to prevent thermal runaway within the battery pack and thermal spread between battery cells, there has recently been an increasing need to develop a battery pack that can minimize damage by effectively discharging gases and flames generated from some battery cells through a discharge device.

In particular, in a battery pack, even if the internal and/or external structure of the battery module changes depending on the cooling method of the battery module, it is necessary to secure a venting structure that allows gas and flames generated inside the battery module to be easily discharged.

The problem to be solved by the present invention is to provide a battery pack and a device including the same having improved cooling performance and improved venting performance through upper and/or lower venting.

The problems to be solved by the present invention are not limited to the problems described above, and problems not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention pertains from this specification and the attached drawings.

According to one embodiment of the present invention, a battery pack comprises: at least one battery module including a battery cell stack including a plurality of battery cells and a module frame accommodating the battery cell stack; a pack frame on which the at least one battery module is mounted; and at least one venting plate positioned between a pack bottom portion, which is a bottom surface of the pack frame, and the at least one battery module, wherein at least one lower venting hole is formed at a lower portion of the module frame, and the venting plate includes at least one venting mesh portion formed at a position facing each of the at least one lower venting hole.

The pack bottom portion includes at least one pack penetration portion formed at a position facing each of the at least one venting mesh portion, and the venting mesh portion may protrude in a direction toward the pack bottom portion.

The above-mentioned venting mesh portion may be fitted into the pack penetration portion.

The device further comprises at least one lower sealing member positioned between the venting plate and the battery module, wherein the lower sealing member comprises at least one sealing penetration portion, and the sealing penetration portion can be positioned between the lower venting hole and the venting mesh portion facing each other.

The above venting plate may have a size equal to or smaller than the bottom surface of the module frame.

The pack frame includes a lower pack frame on which the plurality of battery modules are mounted and an upper pack frame covering an upper portion of the lower pack frame, the lower pack frame includes a pair of horizontal beams extending from the bottom of the pack toward the upper pack frame and at least two vertical beams, the pair of horizontal beams extending along a width direction of the battery module, and the at least two vertical beams are positioned between the pair of horizontal beams and may extend along a length direction of the battery module.

The plurality of battery modules may be separated from each other by the pair of horizontal beams and the at least two vertical beams, and the at least one venting plate may be arranged at the bottom of each of the plurality of battery modules.

The at least one lower sealing member may be respectively positioned between the lower portions of the plurality of battery modules and the at least one venting plate.

In the above battery module, a lower membrane portion covering at least one lower venting hole may be attached.

The device may further include a lower mesh plate covering the lower membrane portion, wherein the lower mesh plate may include at least one lower mesh portion formed at a position facing the at least one lower venting hole.

The battery module may further include at least one upper venting hole formed in an upper portion of the module frame, and may further include at least one upper mesh plate attached to each of the at least one upper venting hole, wherein the upper mesh plate may include an upper mesh portion formed at a position facing the upper venting hole.

It further includes an upper membrane portion positioned between the upper venting hole and the upper mesh plate facing each other, and the upper membrane portion can cover the upper portion of the upper venting hole.

It further includes an upper sealing member positioned between the upper venting hole and the upper mesh plate facing each other, and the upper sealing member can be positioned between the upper venting hole and the upper mesh plate.

The above battery module can directly cool the battery cells by allowing a coolant to flow in the space inside the module frame.

A device according to another embodiment of the present invention includes the battery pack described above.

According to embodiments, the battery pack of the present invention and the device including the same include a lower and/or upper venting structure of the battery pack, so that gas generated from some battery cells included inside the battery module can be easily discharged.

In addition, the battery pack of the present invention and the device including the same can improve the venting performance of the battery pack while maintaining the airtightness for direct cooling of the coolant to the battery cell.

The effects of the present invention are not limited to the effects described above, and effects not mentioned can be clearly understood by a person skilled in the art to which the present invention pertains from this specification and the attached drawings.

FIG. 1 is a perspective view showing a battery pack according to one embodiment of the present invention.
Figure 2 is an exploded perspective view of the battery pack of Figure 1.
FIG. 3 is a perspective view showing the battery pack of FIG. 1 with the upper pack frame and multiple battery modules removed.
Figure 4 is an exploded perspective view of the components included in Figure 3.
FIG. 5 is a top view of a venting plate included in the battery pack of FIG. 1.
FIG. 6 is a cross-sectional view of the venting plate included in the battery pack of FIG. 1 based on the b-b' axis of FIG. 5.
Figure 7 is a perspective view showing the lower part of the battery pack of Figure 1.
Figure 8 is a perspective view of a battery module included in the battery pack of Figure 1.
Figure 9 is an exploded perspective view of the battery module of Figure 8.
Figure 10 is a perspective view showing the lower part of the battery module of Figure 8.
Figure 11 is an exploded perspective view of components located at the bottom of the battery module of Figure 10.
FIG. 12 is a cross-sectional view of a portion of a battery pack based on the a-a' axis of FIG. 2, and FIG. 13 is a drawing showing the flow direction of a coolant when a thermal runaway phenomenon occurs in a battery module included in the battery pack of FIG. 12.
FIG. 14 is a perspective view showing the upper part of a battery module according to another embodiment of the present invention.
Figure 15 is an exploded perspective view of components located on the upper portion of the battery module of Figure 14.
FIG. 16 and FIG. 17 are partial cross-sectional views of a battery pack including the battery module of FIG. 14, taken along the cc axis of FIG. 14, and are drawings showing the venting direction during gas venting.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are used for identical or similar components throughout the specification.

In addition, the size and thickness of each component shown in the drawing are arbitrarily shown for the convenience of explanation, so the present invention is not necessarily limited to what is shown. In the drawing, the thickness is shown enlarged to clearly express several layers and regions. And in the drawing, the thickness of some layers and regions is shown exaggeratedly for the convenience of explanation.

Additionally, throughout the specification, whenever a part is said to “include” a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

Additionally, throughout the specification, when we say "in plan", we mean when the target portion is viewed from above, and when we say "in cross section", we mean when the target portion is viewed from the side in a cross-section cut vertically.

Below, a battery pack according to an embodiment of the present invention is described.

FIG. 1 is a perspective view showing a battery pack according to one embodiment of the present invention. FIG. 2 is an exploded perspective view of the battery pack of FIG. 1. FIG. 3 is a perspective view showing the battery pack of FIG. 1 with the upper pack frame and a plurality of battery modules removed. FIG. 4 is an exploded perspective view of components included in FIG. 3.

Referring to FIGS. 1 and 2, a battery pack (1000) according to one embodiment of the present invention includes at least one battery module (100) including a battery cell stack (110, FIG. 9) including a plurality of battery cells (111, FIG. 9) and a module frame (200, FIG. 9) that accommodates the battery cell stack (110, FIG. 9), and a pack frame (1100, 1400) on which at least one battery module (100) is mounted.

Here, the pack frame (1100, 1400) may include a lower pack frame (1100) on which a plurality of battery modules (100) are mounted, and an upper pack frame (1400) positioned above the battery modules (100). More specifically, the upper pack frame (1400) may cover the upper portion of the lower pack frame (1100) in a state in which a plurality of battery modules (100) are mounted on the lower pack frame (1100). Here, the lower pack frame (1100) and the upper pack frame (1400) may be joined at surfaces that come into contact with each other by a method such as welding or adhesion, thereby sealing the inside of the battery pack (1000).

Referring to FIGS. 2 and 4, the lower pack frame (1100) may include a pack bottom portion (1200) that faces the lower surface of the battery module (100) as the bottom surface of the pack frame (1100, 1400).

For example, the lower pack frame (1100) may include a frame portion (1300) extending from the pack bottom portion (1200) toward the upper pack frame (1400). More specifically, the frame portion (1300) includes a pair of horizontal beams (1310) and at least two vertical beams (1350). Here, the pair of horizontal beams (1310) may extend along the width direction (x-axis direction) of the battery module (100). In addition, the at least two vertical beams (1350) may be positioned between the pair of horizontal beams (1310) and may extend along the length direction (y-axis direction) of the battery module (100).

A plurality of battery modules (100) may be partitioned from each other by a pair of horizontal beams (1310) and at least two vertical beams (1350). That is, an internal space partitioned by a pair of horizontal beams (1310) and at least two vertical beams (1350) may be a module area where each battery module (100) is mounted, and may be an area where other electrical components are mounted in addition to the battery module (100).

In the lower pack frame (1100), the pack bottom portion (1200) and the frame portion (1300) may be integral with each other, or may be fixed to each other by a separate fastening method such as welding or bonding. In addition, here, a pair of horizontal beams (1310) and at least two vertical beams (1350) may be integral with each other, or may be fixed to each other by a separate fastening method such as welding or bonding.

For example, the frame portion (1300) may be formed of an insulating material. For example, the frame portion (1300) may be formed of an aluminum extrusion structure. As another example, the frame portion (1300) may be formed of a dissimilar metal bonding material such as a clad metal, or may be a structure including an insulating material such as an aerogel or an EPP (Expanded Polypropylenes) foam. As another example, the frame portion (1300) may be a structure including a material such as a silicon foam, a mica, or a glass fiber pad. However, the present invention is not limited thereto, and the frame portion (1300) may be used without limitation as long as it is formed of an insulating material having a predetermined rigidity.

However, the configuration of the frame portion (1300) is not limited thereto, and any configuration that allows multiple battery modules (100) to be mounted while partitioning each other may be included in the present embodiment. In addition, the length, spacing, etc. of a pair of horizontal beams (1310) and at least two vertical beams (1350) may be adjusted according to the size of the battery module (100).

Accordingly, in the battery pack (1000) according to the present embodiment, the lower pack frame (1100) can be positioned spaced apart from each other as the plurality of battery modules (100) are partitioned from each other by the frame portion (1300), and even if a fire occurs in some of the plurality of battery modules (100), the heat transfer phenomenon between adjacent battery modules (100) can be effectively prevented.

Referring to FIGS. 3 and 4, a battery pack (1000) according to the present embodiment includes at least one venting plate (1500) positioned between a pack bottom portion (1200) facing the lower surface of a battery module (100) and at least one battery module (100).

Here, at least one venting plate (1500) may be respectively arranged in a module area partitioned by a frame portion (1300). More specifically, at least one venting plate (1500) may be respectively arranged in a module area partitioned by a pair of horizontal beams (1310) and at least two vertical beams (1350). In other words, at least one venting plate (1500) may be respectively arranged in a lower portion of a plurality of battery modules (100).

For example, the venting plate (1500) may have a size equal to or smaller than the bottom surface of the battery module (100). More specifically, the venting plate (1500) may have a size equal to or smaller than the bottom surface of the module frame (200, FIG. 8) included in the battery module (100).

FIG. 5 is a top view of a venting plate included in the battery pack of FIG. 1. FIG. 6 is a cross-sectional view of the venting plate included in the battery pack of FIG. 1 taken along the b-b’ axis of FIG. 5.

Referring to FIGS. 4 to 6, the venting plate (1500) includes a venting bottom portion (1510) and at least one venting mesh portion (1550). Here, the venting mesh portion (1550) may protrude in a direction toward the pack bottom portion (1200) based on the venting bottom portion (1510). In addition, at least one venting mesh portion (1550) may be arranged to be spaced apart from each other along the longitudinal direction (y-axis direction) of the battery module (100).

Here, the venting mesh portion (1550) may have a mesh structure as in Fig. 6. For example, the venting mesh portion (1550) may be made of aluminum (Al). However, the material of the venting mesh portion (1550) is not limited thereto, and any material that has heat resistance against gas and flame generated from the battery module (100) and allows the gas to be easily discharged may be included in this embodiment.

Accordingly, in the battery pack (1000) according to the present embodiment, the venting plates (1500) are each positioned at the bottom of the battery modules (100), so that gas generated from the battery modules (100) can be easily discharged in the lower direction of the battery modules (100) through the venting mesh portion (1550), and the heat transfer phenomenon between adjacent battery modules (100) can be effectively prevented.

Referring to FIG. 4, the pack bottom portion (1200) may include at least one pack penetration portion (1250) formed at a position facing at least one venting mesh portion (1550). In addition, the at least one pack penetration portion (1250) may be spaced apart from each other along the longitudinal direction (y-axis direction) of the battery module (100), like the at least one venting mesh portion (1550). Here, the pack bottom portion (1200) and the venting plate (1500) may be in contact with each other. For example, the venting mesh portion (1550) may be fitted into the pack penetration portion (1250).

Accordingly, in the battery pack (1000) according to the present embodiment, the venting plate (1500) can be stably fixed to the pack bottom (1200), while maintaining airtightness between the venting plate (1500) and the pack bottom (1200).

Referring to FIGS. 3 and 4, the battery pack (1000) according to the present embodiment may further include at least one lower sealing member (1600) positioned between the venting plate (1500) and the battery module (100). More specifically, at least one lower sealing member (1600) may be positioned between the lower portions of the plurality of battery modules (100) and at least one venting plate (1300).

For example, the lower sealing member (1600) may have a size that is the same as or smaller than the bottom surface of the battery module (100). More specifically, the lower sealing member (1600) may have a size that is the same as or smaller than the venting bottom portion (1510) of the venting plate (1500). However, the size of the lower sealing member (1600) is not limited thereto, and any size that can secure the lower portion of the battery module (100) and the venting plate (1500) to each other while maintaining airtightness between the lower portion of the battery module (100) and the venting plate (1500) may be included in the present embodiment.

For example, the lower sealing member (1600) may be formed by a sealing pad or by applying and curing a sealant. However, the present invention is not limited thereto, and any form that can secure the lower part of the battery module (100) and the venting plate (1500) to each other while maintaining airtightness between the lower part of the battery module (100) and the venting plate (1500) may be included in the present embodiment.

Additionally, the lower sealing member (1600) may include a lower sealing bottom surface (1610) and at least one sealing penetration portion (1650). Here, the sealing penetration portion (1650) may be located between the lower surface of the battery module (100) and the venting mesh portion (1550).

Accordingly, in the battery pack (1000) according to the present embodiment, the lower sealing member (1600) can maintain airtightness between the lower part of the battery module (100) and the venting plate (1500), while allowing gas discharged from the lower part of the battery module (100) to be easily discharged to the venting plate (1500) through the sealing penetration portion (1650).

Figure 7 is a perspective view showing the lower part of the battery pack of Figure 1.

Referring to FIG. 1, FIG. 4, and FIG. 7, the venting mesh portion (1550) of the venting plate (1500) may be exposed to the outside through the pack penetration portion (1250) of the pack bottom portion (1200). That is, the venting mesh portion (1550) may be exposed to the lower portion of the lower pack frame (1100).

Accordingly, in the battery pack (1000) according to the present embodiment, when a thermal runaway phenomenon occurs in some of the battery modules (100) among the plurality of battery modules (100), the gas generated in the battery module (100) may be discharged toward the lower portion of the lower pack frame (1100).

That is, the battery pack (1000) according to the present embodiment has an advantage in that gas generated from the battery module (100) is discharged in a downward direction of the battery pack (1000), thereby inducing venting in a direction opposite to the driver's seat of the vehicle in which the battery pack (1000) is mounted.

Below, a battery module (100) mounted in a battery pack (1000) according to the present embodiment is described in detail.

Fig. 8 is a perspective view of a battery module included in the battery pack of Fig. 1. Fig. 9 is an exploded perspective view of the battery module of Fig. 8.

Referring to FIGS. 8 and 9, a battery module (100) according to one embodiment of the present invention includes a battery cell stack (110) including a plurality of battery cells (111), a module frame (200) that accommodates the battery cell stack (110), end plates (300) positioned at the front and rear of the battery cell stack (110), and a cooling port (350) for circulating a coolant into the interior of the module frame (200).

Here, the battery cell stack (110) may be one battery cell stack, or two or more battery cell stacks may be arranged along the longitudinal direction (y-axis direction) of the battery module.

First, the battery cell (111) is a pouch-shaped battery cell and may include electrode leads (130) protruding in both directions. This pouch-shaped battery cell may be formed by housing an electrode assembly in a pouch case of a laminate sheet including a resin layer and a metal layer, and then bonding the outer periphery of the pouch case. This battery cell (111) may have a rectangular sheet structure.

These battery cells (111) may be configured in multiple pieces, and the multiple battery cells (111) are stacked so as to be electrically connected to each other to form a battery cell stack (110). In particular, the battery cells (111) may be stacked along one direction while standing upright and facing each other with one side of the main body of the battery cells (111). More specifically, as illustrated in FIG. 9, the battery cells (111) may be stacked in a direction from one side of the side of the module frame (200) to the other side while standing upright so that one side of the main body of the battery cell (111) is parallel to the side sides of the module frame (200). As an example, a shape in which multiple battery cells (111) are stacked along a direction parallel to the x-axis is illustrated.

The battery case (not shown) of the battery cell (111) is generally composed of a laminate structure of a resin layer/metal film layer/resin layer. For example, if the surface of the battery case is composed of an O(oriented)-nylon layer, when a plurality of battery cells are laminated to form a medium- or large-sized battery module, there is a tendency for it to slip easily due to external impact. Therefore, in order to prevent this and maintain a stable laminated structure of the battery cells, the battery cell laminate (110) can be formed by attaching an adhesive material, such as a double-sided tape or an adhesive adhesive that is bonded by a chemical reaction during bonding, to the surface of the battery case.

The module frame (200) may be intended to protect the battery cell stack (110) and electrical components connected thereto from external physical impact. The battery cell stack (110) and electrical components connected thereto may be accommodated in the internal space of the module frame (200).

The structure of the module frame (200) may vary. According to one embodiment of the present invention, the structure of the module frame (200) may be a mono-frame structure. Here, the mono-frame may be in the form of a metal plate in which the upper surface, lower surface, and both side surfaces are integrated. The mono-frame may be manufactured by extrusion molding.

However, the structure of the module frame (200) is not limited thereto, and in another embodiment, the module frame (200) may have a structure in which a U-shaped frame and an upper plate are combined. In this case, the U-shaped frame may have both side surfaces extending upward from the lower surface and both edges of the lower surface, and the upper plate may have a plate shape. At this time, each frame or plate constituting the U-shaped frame may be manufactured by press forming. In addition, the structure of the module frame (200) may be provided as an L-shaped frame structure in addition to a mono-frame or a U-shaped frame, and may be provided as various structures not described in the above-described examples.

The module frame (200) may be open on both sides. More specifically, the module frame (200) may be provided in an open form along the length direction of the battery cell (111). In this case, the front and rear sides of the battery cell stack (110) may not be covered by the module frame (200). The front and rear sides of the battery cell stack (110) may be covered by a bus bar assembly (400), a sealing assembly (500), an end plate (300), etc., which will be described later, and through this, the front and rear sides of the battery cell stack (110) may be protected from external physical impacts, etc.

The battery module (100) may include busbar assemblies (400) positioned on the front and rear sides of the battery cell stack (110), respectively. Specifically, the busbar assemblies (400) may be positioned in the direction in which the electrode leads (not shown) of the battery cells (111) included in the battery cell stack (110) protrude. The busbar assemblies (400) may each include a busbar frame, a busbar, and a terminal busbar, which will be described later.

The battery module (100) may include a sealing assembly (500). The sealing assembly (500) may be formed to cover the battery cell stack (110) by being positioned on both open sides of the module frame (200). The sealing assembly (500) may separate the open sides of the module frame (200) from the external environment. Specifically, the sealing assembly (500) may perform a role of sealing the inside of the module frame (200) to prevent the coolant from leaking to the outside when the coolant is injected into the inside of the module frame (200) described below.

The end plate (300) may be formed to cover the sealing assembly (500) by being positioned on both open sides of the module frame (200). The end plate (300) may physically protect the battery cell stack (110) and other electrical components from external impact.

The battery module (100) according to the present embodiment can directly cool the battery cells (111) by allowing the coolant to flow in the space inside the module frame (200). More specifically, the battery module (100) can further include a cooling port (350) for circulating the coolant into the inside of the module frame (200). More specifically, the cooling port (350) can be located on the end plates (300) located on the front and rear sides of the battery cell stack (110), respectively.

For example, the coolant introduced into the cooling port (350) included in the end plate (300) located at the front of the battery cell stack (110) may be introduced into the module frame (200) through the coolant hole (500h) of the sealing assembly (500). In addition, the coolant introduced into the module frame (200) may be discharged to the outside of the battery module (100) through the cooling port (350) included in the end plate (300) located at the rear of the battery cell stack (110) through the coolant hole (500h) of the sealing assembly (500).

Accordingly, the refrigerant can directly contact the battery cell stack (110), bus bar assembly (400), and other electrical components housed inside the module frame (200) and receive heat generated therefrom.

For example, the refrigerant may be a fluid. However, since the refrigerant directly contacts the battery cell stack (110), the bus bar assembly (400), and other electrical components within the battery module (100), the refrigerant needs to be electrically insulated. Accordingly, the refrigerant may be a material having insulating properties. For example, the refrigerant may be an insulating oil.

That is, in the case of the present embodiment, the refrigerant can directly cool the battery cell stack (110), busbar assembly (400), and other electrical components that generate heat within the battery module (100) by directly contacting them and transferring heat to them.

Accordingly, compared to indirectly cooling the battery module using a heat sink or the like in a conventional battery module, the battery module (100) according to the present embodiment can have improved cooling efficiency through direct cooling, thereby extending the life of the battery.

Below, the lower part of the battery module (100) mounted in the battery pack (1000) according to the present embodiment will be described.

Fig. 10 is a perspective view showing the lower portion of the battery module of Fig. 8. Fig. 11 is an exploded perspective view of components located at the lower portion of the battery module of Fig. 10.

Referring to FIGS. 10 and 11, in the battery pack (1000) according to the present embodiment, the battery module (100) may have at least one lower venting hole (250) formed in the lower portion of the module frame (200). More specifically, the lower venting hole (250) may be formed by penetrating the lower portion of the module frame (200), and the battery cell stack (110) positioned inside the module frame (200) may be exposed to the outside through the lower venting hole (250).

At least one lower venting hole (250) may be arranged to be spaced apart from each other along the longitudinal direction (y-axis direction) of the battery module (100). In addition, as shown in FIG. 4, at least one lower venting hole (250) may be formed at a position facing at least one venting mesh portion (1550) formed in the venting plate (1500). In addition, as shown in FIG. 4, a sealing penetration portion (1650) of a lower sealing member (1600) may be positioned between the lower venting hole (250) and the venting mesh portion (1550) facing each other. In other words, each of the lower venting hole (250), the venting mesh portion (1550), and the sealing penetration portion (1650) may be positioned on the same vertical line.

Accordingly, in the battery pack (1000) according to the present embodiment, when a thermal runaway phenomenon occurs in some of the battery cells (111) included in the battery module (100), the gas generated in the battery cell (111) can be discharged to the outside of the battery module (100) through the lower venting hole (250), and the gas discharged through the lower venting hole (250) can be discharged toward the venting mesh part (1550) through the sealing penetration part (1650). That is, in the battery pack (1000) according to the present embodiment, the internal gas of the battery module (100) can be easily discharged through the lower venting hole (250), so that when a thermal runaway phenomenon occurs, the internal pressure of the battery module (100) can be effectively reduced.

Referring to FIGS. 10 and 11, in the battery module (100), a lower membrane portion (700) covering at least one lower venting hole (250) may be attached. For example, the lower membrane portion (700) may be attached to the lower portion of the module frame (200) by an adhesive method such as laser welding.

More specifically, the lower membrane portion (700) may extend along the lower portion of the battery module (100). For example, the lower membrane portion (700) may be in a form that covers at least one lower venting hole (250) as shown in FIG. 11. However, it is not limited thereto, and unlike FIG. 11, a case in which each lower venting hole (250) is covered by a plurality of lower membrane portions (700) may also be included in the present embodiment.

For example, the lower membrane portion (700) may be made of a material such as PTFE (Polytetrafluoroethylene or Teflon®). However, the present invention is not limited thereto, and the lower membrane portion (700) may be made of a material that prevents the coolant flowing inside the battery module (100) from leaking while allowing the internal gas to be discharged to the outside, if it is included in the present embodiment.

Accordingly, in the battery pack (1000) according to the present embodiment, when the battery module (100) has a structure in which a coolant flows inside, the lower membrane portion (700) can maintain the airtightness of the inside of the battery module (100) and prevent the coolant from leaking to the outside. In addition, the lower membrane portion (700) can allow gas inside the battery module (100) to be discharged to the outside.

FIG. 12 is a cross-sectional view of a portion of a battery pack based on the a-a’ axis of FIG. 2, and FIG. 13 is a drawing showing the flow direction of a coolant when a thermal runaway phenomenon occurs in a battery module included in the battery pack of FIG. 12.

Referring to FIG. 12, the lower membrane portion (700) covers the lower venting hole (250) when the battery module (100) is operating normally, thereby preventing the refrigerant flowing inside the battery module (100) from leaking to the outside. In addition, even if a thermal runaway phenomenon occurs in the battery module (100), the gas inside the battery module (100) can be discharged to the outside through the lower membrane portion (700) for a certain period of time.

In contrast, referring to FIG. 13, when a thermal runaway phenomenon occurs in some of the battery cells (111) included in the battery module (100) and the temperature and pressure inside the battery module (100) increase, a part of the lower membrane part (700) may be lost or damaged. In this case, a part of the refrigerant inside the battery module (100) may be discharged to the outside of the battery module (100) through the lost or damaged part of the lower membrane part (700). That is, a part of the refrigerant inside the battery module (100) may be discharged toward the venting plate (1500) located at the bottom of the battery module (100).

Referring to FIGS. 10 and 11, the battery module (100) may further include a lower mesh plate (600) covering the lower membrane portion (700). More specifically, the lower mesh plate (600) may include at least one lower mesh portion (650) formed at a position facing the lower mesh bottom portion (610) and at least one lower venting hole (250).

Here, the lower mesh portion (650) may have a mesh structure like the venting mesh portion (1550) of Fig. 6. For example, the lower mesh portion (650) may be made of aluminum (Al). However, the material of the lower mesh portion (650) is not limited thereto, and any material that has heat resistance against gas and flame generated from the battery module (100) and allows the gas to be easily discharged may be included in the present embodiment.

Accordingly, in the battery pack (1000) according to the present embodiment, when the battery module (100) is operating normally, the lower mesh plate (600) can protect the lower membrane portion (700) from the external environment. In addition, referring to FIG. 12, even if a thermal runaway phenomenon occurs in the battery module (100), the gas discharged from the lower membrane portion (700) can be discharged to the outside through the lower mesh portion (650).

In addition, referring to FIG. 13, when a thermal runaway phenomenon occurs in some of the battery cells (111) included in the battery module (100) and the temperature and pressure inside the battery module (100) increase, the lower mesh plate (600) may allow some of the coolant inside the battery module (100) discharged through a missing or damaged portion of the lower membrane portion (700) to be discharged to the outside through the lower mesh portion (650), but the mesh structure formed in the lower mesh portion (650) can reduce the speed at which the coolant leaks.

In addition, the refrigerant introduced into the lower mesh portion (650) can be discharged toward the venting plate (1500) along the direction of gravity (z-axis direction), and the venting mesh portion (1550) included in the venting plate (1500) can further reduce the rate at which the refrigerant leaks. In this case, the rate at which the refrigerant leaks from the battery module (100) through the lower mesh portion (650) and the venting mesh portion (1550) can be lower than the rate at which the refrigerant flows into the battery module (100), so that the inside of the battery module (100) can maintain a state in which the refrigerant is immersed.

That is, even if a thermal runaway phenomenon occurs in some battery cells (111) located inside the battery module (100), the inside of the battery module (100) can be maintained in a state of being immersed in a coolant, so there is an advantage in that heat transfer can be effectively blocked at the initial stage of battery cell ignition.

Below, the upper part of the battery module (100) mounted on the battery pack (1000) according to the present embodiment will be described.

Fig. 14 is a perspective view showing the upper portion of a battery module according to another embodiment of the present invention. Fig. 15 is an exploded perspective view of components located at the upper portion of the battery module of Fig. 14.

Referring to FIGS. 14 and 15, in the battery pack (1000) according to the present embodiment, the battery module (100a) may further include at least one upper venting hole (290a) formed on the upper portion of the module frame (200a). Other components may be described in the same manner as described with reference to FIGS. 8 to 13.

The upper venting hole (290a) may be formed through the upper portion of the module frame (200a), and the battery cell stack (110a) positioned inside the module frame (200a) may be exposed to the outside through the upper venting hole (290a). At least one upper venting hole (290a) may be arranged spaced apart from each other along the longitudinal direction (y-axis direction) of the battery module (100a).

Accordingly, in the battery pack (1000) according to the present embodiment, when a thermal runaway phenomenon occurs in the battery module (100a), the gas inside the battery module (100a) can be discharged to the outside of the battery module (100a) through the upper venting hole (290a). That is, in the battery pack (1000) according to the present embodiment, the internal gas in the battery module (100a) can be effectively discharged through the lower venting hole (250, FIG. 11) and the upper venting hole (290a), so that when a thermal runaway phenomenon occurs, the internal pressure of the battery module (100a) can be reduced more effectively.

Referring to FIGS. 14 and 15, the battery module (100) according to the present embodiment may further include an upper membrane portion (900a) positioned between the upper venting hole (290a) and the upper mesh plate (800a) facing each other. Here, the upper membrane portion (900a) may cover the upper portion of the upper venting hole (290a). For example, the upper membrane portion (900a) may be attached to the upper portion of the module frame (200) by an adhesive method such as laser welding.

However, the shape of the upper membrane portion (900a) is not limited to FIGS. 14 and 15, and may have a shape that extends long along the length direction of the battery module (100), like the lower membrane portion (700) of FIG. 11.

For example, the upper membrane portion (900a) may be made of a material such as PTFE (Polytetrafluoroethylene or Teflon®). However, the present invention is not limited thereto, and the upper membrane portion (900a) may be made of a material that prevents the coolant flowing inside the battery module (100a) from leaking while allowing the internal gas to be discharged to the outside, if it is included in the present embodiment.

Accordingly, in the battery pack (1000) according to the present embodiment, when the battery module (100a) has a structure in which a coolant flows inside, the upper membrane portion (900a) can maintain the airtightness of the inside of the battery module (100a) and prevent the coolant from leaking to the outside. In addition, the upper membrane portion (900a) can allow gas inside the battery module (100a) to be discharged to the outside.

FIG. 16 and FIG. 17 are partial cross-sectional views of a battery pack including the battery module of FIG. 14, taken along the c-c axis of FIG. 14, showing the venting direction during gas venting.

Referring to FIG. 16, the upper membrane portion (900a) covers the upper venting hole (290a) when the battery module (100) is operating normally, thereby preventing the coolant flowing inside the battery module (100a) from leaking to the outside. In addition, even if a thermal runaway phenomenon occurs in the battery module (100a), the gas inside the battery module (100a) can be discharged to the outside through the upper membrane portion (900a) for a certain period of time.

In contrast, referring to FIG. 17, when a thermal runaway phenomenon occurs in the battery module (100a) and the temperature and pressure inside the battery module (100a) increase, a part of the upper membrane portion (900a) may be lost or damaged.

However, the upper membrane portion (900a) is located at the top with respect to the direction of gravity, unlike the lower membrane portion (700), and thus may have less direct contact with the refrigerant flowing inside the battery module (100a). That is, the lower membrane portion (700) may be lost or damaged before the upper membrane portion (900a), and thus the refrigerant flowing inside the battery module (100) may leak toward the lower mesh portion (650) and the venting mesh portion (1550).

However, if the upper membrane portion (900a) is lost or damaged, some of the refrigerant inside the battery module (100a) may be discharged to the outside of the battery module (100a) through that portion. However, as described above, in the case of the upper membrane portion (900a), unlike the lower membrane portion (700), it is located at the top with respect to the direction of gravity, so that the amount of refrigerant inside the battery module (100a) that leaks may be relatively very small.

As another example, the upper membrane portion (900a) may be replaced with an upper sealing member. Here, the upper sealing member may be in the form of a sealing pad or a sealant applied and hardened. In the case of the upper sealing member, similarly to the upper membrane portion (900a), the upper venting hole (290a) may be covered during normal operation of the battery module (100a), thereby preventing the refrigerant flowing inside the battery module (100a) from leaking to the outside. However, in the case of the upper sealing member, unlike the upper membrane portion (900a), the gas inside the battery module (100a) may not be discharged to the outside.

In addition, when a thermal runaway phenomenon occurs in the battery module (100a) and the temperature and pressure inside the battery module (100a) increase, the upper sealing member may be partially lost or damaged, similar to the upper membrane portion (900a). In this case, through the lost or damaged portion of the upper sealing member, a portion of the gas and refrigerant inside the battery module (100a) may be discharged to the outside of the battery module (100a). However, even in the case of the upper sealing member, unlike the lower membrane portion (700), since it is located at the top with respect to the direction of gravity, a relatively small amount of refrigerant inside the battery module (100a) may leak.

Referring to FIGS. 14 and 15, the battery module (100a) according to the present embodiment may further include at least one upper mesh plate (800a) attached to at least one upper venting hole (290a), respectively. In addition, the upper mesh plate (800a) may have an upper mesh portion formed at a position facing the upper venting hole (290a). However, the shape of the upper mesh plate (800a) is not limited to FIGS. 14 and 15, and may have a shape that extends long along the longitudinal direction of the battery module (100), such as the lower mesh plate (600) of FIG. 11.

Here, the upper mesh portion included in the upper mesh plate (800a) may have a mesh structure like the venting mesh portion (1550) of Fig. 6. For example, the upper mesh portion may be made of aluminum (Al). However, the material of the upper mesh portion is not limited thereto, and any material that has heat resistance against gas and flame generated from the battery module (100a) and allows the gas to be easily discharged may be included in this embodiment.

Accordingly, in the battery pack (1000) according to the present embodiment, when the battery module (100a) is operating normally, the upper mesh plate (800a) can protect the upper membrane portion (900a) from the external environment. In addition, referring to FIG. 17, even if a thermal runaway phenomenon occurs in the battery module (100), the gas discharged from the upper membrane portion (900a) can be discharged to the outside through the upper mesh portion.

In addition, referring to FIG. 17, when a thermal runaway phenomenon occurs in the battery module (100a) and the temperature and pressure inside the battery module (100a) rise, the upper mesh plate (800a) may discharge some of the refrigerant inside the battery module (100a) that is discharged through a missing or damaged portion of the upper membrane portion (900a) to the outside through the upper mesh portion, but the amount of the refrigerant leaking can be minimized through the mesh structure formed in the upper mesh portion. That is, even if a thermal runaway phenomenon occurs in the battery module (100a), the refrigerant inside the battery module (100a) is prevented from leaking upward, so that the state of being immersed in the refrigerant can be maintained, and there is an advantage in that heat transfer can be effectively blocked at the initial stage of battery cell ignition.

A device according to another embodiment of the present invention includes the battery pack described above. Such a device may be applied to means of transportation such as an electric bicycle, an electric vehicle, a hybrid vehicle, etc., but the present invention is not limited thereto and may be applied to various devices that can use a battery module and a battery pack including the same, which also fall within the scope of the present invention.

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

100: Battery module
110: Battery cell stack
300: End Plate
350: Cooling Port
400: Busbar assembly
500: Sealing assembly
600: Lower mesh plate
700: Lower membrane section
1000: Battery Pack
1100: Lower pack frame
1200: Bottom of pack
1300: Frame section
1310: Horizontal beam
1350: Vertical beam
1400: Upper pack frame
1500: Venting Plate
1600: Lower sealing absence

Claims (15)

At least one battery module comprising a battery cell stack including a plurality of battery cells and a module frame for accommodating the battery cell stack;
a pack frame on which at least one battery module is mounted; and
At least one venting plate positioned between the pack bottom, which is the bottom surface of the pack frame, and the at least one battery module,
At least one lower venting hole is formed at the bottom of the above module frame,
A battery pack wherein the venting plate includes at least one venting mesh portion formed at a position facing each of the at least one lower venting hole. In paragraph 1,
The pack bottom portion includes at least one pack penetration portion formed at a position facing each of the at least one venting mesh portion,
A battery pack in which the above-mentioned venting mesh portion protrudes in a direction toward the bottom of the pack. In paragraph 2,
A battery pack in which the above-mentioned venting mesh portion is fitted into the above-mentioned pack penetration portion. In paragraph 2,
Further comprising at least one lower sealing member positioned between the venting plate and the battery module;
The lower sealing member comprises at least one sealing penetration,
A battery pack in which the sealing penetration portion is located between the lower venting hole and the venting mesh portion facing each other. In Article 4,
A battery pack wherein the above venting plate has a size equal to or smaller than the bottom surface of the module frame. In Article 4,
The above pack frame includes a lower pack frame on which the plurality of battery modules are mounted and an upper pack frame covering the upper portion of the lower pack frame,
The lower pack frame comprises a pair of horizontal beams and at least two vertical beams extending from the bottom of the pack toward the upper pack frame,
The above pair of horizontal beams extend along the width direction of the battery module,
A battery pack wherein the at least two vertical beams are positioned between the pair of horizontal beams and extend along the length direction of the battery module. In Article 6,
The above plurality of battery modules are separated from each other by the pair of horizontal beams and at least two vertical beams,
A battery pack wherein at least one venting plate is disposed at the lower portion of each of the plurality of battery modules. In Article 7,
A battery pack wherein at least one lower sealing member is respectively positioned between the lower portions of the plurality of battery modules and the at least one venting plate. In paragraph 1,
A battery pack having a lower membrane portion attached thereto that covers at least one lower venting hole in the above battery module. In Article 9,
Further comprising a lower mesh plate covering the lower membrane portion;
A battery pack wherein the lower mesh plate includes at least one lower mesh portion formed at a position facing the at least one lower venting hole. In paragraph 1,
The above battery module further includes at least one upper venting hole formed on the upper portion of the module frame,
Further comprising at least one upper mesh plate, each attached to at least one upper venting hole;
The upper mesh plate is a battery pack including an upper mesh portion formed at a position facing the upper venting hole. In Article 11,
Further comprising an upper membrane portion positioned between the upper venting hole and the upper mesh plate facing each other,
The upper membrane portion is a battery pack that covers the upper portion of the upper venting hole. In Article 11,
Further comprising an upper sealing member positioned between the upper venting hole and the upper mesh plate facing each other,
A battery pack wherein the upper sealing member is positioned between the upper venting hole and the upper mesh plate. In paragraph 1,
The above battery module is a battery pack in which a coolant flows in the space inside the module frame and directly cools the battery cells. A device comprising a battery pack according to claim 1.