CN117957690A - Battery pack with improved safety - Google Patents

Abstract

A battery pack according to an embodiment of the present invention includes: a cell module assembly including a cell stack in which a plurality of battery cells are stacked; a battery pack housing configured to store the cell module assembly and having an open upper surface; and a fire-fighting pot located above the cell module assembly and covering the battery pack case, the fire-fighting pot including an inner space containing a fire extinguishing agent and a plurality of weak portions that are portions in which a thickness of a base plate of the fire-fighting pot is relatively thin, wherein the weak portions are opened by melting due to heat from the cell when the cell is overheated.

Description

Battery pack with improved safety

Technical Field

Cross reference to related applications

This application claims the benefits of korean patent application nos. 10-2021-0185391 and 2022, 12-0169563, filed by the korean intellectual property office on 22 nd 12, 2021, and 7 th 12, 2022, which are incorporated herein by reference in their entirety.

The present disclosure relates to a battery, and more particularly, to a battery pack or the like configured to ensure safety even when a thermal event occurs.

Background

The secondary batteries currently in wide use include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, lithium secondary batteries, and the like. Among them, lithium secondary batteries have been attracting attention because they have advantages such as hardly exhibiting a memory effect and thus being freely charged and discharged, and have very low self-discharge rate and high energy density, as compared with nickel-based secondary batteries.

Such lithium secondary batteries mainly use lithium-based oxides and carbonaceous materials as a positive electrode active material and a negative electrode active material, respectively. The lithium secondary battery includes: electrode assemblies in which positive and negative electrode plates each coated with positive and negative electrode active materials are disposed with a separator interposed therebetween; and an exterior material, i.e., a battery case, which seals and accommodates the electrode assembly together with the electrolyte solution.

In general, lithium secondary batteries can be classified into, depending on the shape of the external material: a can type secondary battery in which an electrode assembly is mounted in a metal can; and a pouch-type secondary battery in which the electrode assembly is mounted in a pouch of the aluminum laminate sheet.

Such secondary batteries are widely used not only in small-sized devices such as portable electronic devices but also in medium-and large-sized devices such as electric vehicles and Energy Storage Systems (ESS), and their use is rapidly increasing. Moreover, in recent years, there is an increasing trend to use a home battery pack as an application for storing electric power.

Various battery packs including a home battery pack include a plurality of battery cells (secondary batteries) to increase capacity and/or output. In particular, in order to increase the energy density of the battery pack, a plurality of battery cells are often densely disposed in a very narrow space.

One of the typically important issues in such battery pack configurations is safety. In particular, when a thermal event occurs in any one of a plurality of battery cells included in a battery pack, it is necessary to suppress the propagation of such event to other battery cells. If the heat propagation between the battery cells is not properly suppressed, this causes a thermal event in several battery cells included in the battery pack, which may cause greater problems such as ignition or explosion of the battery pack. Moreover, a fire or explosion generated in the battery pack may cause great damage to surrounding human lives or properties. In particular, in the case of a home battery pack, if fire or explosion occurs, this can impair the safety of people living in a house and spread into a house fire, thereby causing greater damage.

Disclosure of Invention

Technical problem

Accordingly, the present disclosure has been designed to solve the above-mentioned problems, and therefore, an object of the present disclosure is to provide a battery pack or the like, the structure of which is improved so as to appropriately control thermal events generated inside the battery pack.

However, the technical problems to be solved by the embodiments of the present disclosure are not limited to the problems described above, and still other problems not mentioned above will be clearly understood by those skilled in the art from the description of the appended claims.

Technical proposal

To achieve the above object, according to one aspect of the present disclosure, there is provided a battery pack including: a cell module assembly having one or more battery cells; a battery pack case accommodating the unit module assembly in the inner space; and a fire-fighting tank storing a fire extinguishing agent and disposed on an upper portion of the unit module assembly.

Wherein the fire tank may be configured to discharge the fire extinguishing agent toward the unit module assembly when heat is applied from the unit module assembly.

The fire tank may be configured such that at least a portion thereof is melted by heat applied from the unit module assembly.

The fire canister may be configured to melt by venting gas sprayed from the battery cell or the temperature of the battery cell.

The fire tank may store the fire extinguishing agent in a liquid state.

The fire canister may be configured such that the thickness of the base plate is different for each location.

The fire-fighting pot may be located at a central portion between the cells in which the fragile portion having a relatively thin thickness is stacked in the horizontal direction.

The battery pack case may be configured to be stacked in a vertical direction.

To achieve the above object, according to another aspect of the present disclosure, there is provided an energy storage system including one or more battery packs according to the present disclosure.

According to one embodiment of the present disclosure, there is provided a battery pack including: a cell module assembly including a cell stack in which a plurality of battery cells are stacked; a battery pack case configured to accommodate the unit module assembly and open at an upper surface thereof; and a fire-fighting pot located above the cell module assembly and covering the battery pack case, wherein the fire-fighting pot may include: an interior space containing a fire extinguishing agent; and a plurality of weak portions, which are relatively thin portions where the thickness of the base plate of the fire pot is relatively thin, and are melted and opened by a thermal event of the battery cell.

The fragile parts have a linear shape and are arranged in parallel with one edge of the fire-fighting pot, the corresponding fragile parts are arranged in parallel with each other, and the longitudinal direction of the fragile parts and the longitudinal direction of the battery cell may be orthogonal to each other.

The fragile parts have a linear shape and are arranged in parallel with one edge of the fire-fighting pot, the respective fragile parts are arranged in parallel with each other, the longitudinal direction of the fragile parts and the longitudinal direction of the battery cells are parallel with each other, and the fragile parts may be disposed between two battery cells adjacent to each other.

The fire fighting pot can be made by plastic injection moulding.

The base plate of the fire canister has a step difference, and the height of the portion where the plurality of fragile portions are placed may be lowest.

The single module assembly includes: a pair of bus bar housings disposed on the front and rear surfaces of the battery cell stack; and a pair of end plates disposed parallel to the battery cells at both ends of the battery cell stack, wherein the pair of end plates may be connected between the pair of bus bar housings.

The cell module assembly may include a band connecting upper and lower sides of the pair of end plates of the battery cell stack, thereby reinforcing the coupling of the cell module assembly.

The substrate has a step difference, and a height of a portion where the plurality of fragile portions are placed may be lower than a height of a portion placed on the belt.

The battery pack further includes a plate-shaped blocking member disposed between the adjacent battery cells, wherein the blocking member may include a support plate and a pair of bump spacers disposed on both surfaces of the support plate.

The fire suppressant may be a liquid fire suppressant.

The battery pack case is made of a box shape having an opened upper surface, and may be integrally formed or manufactured such that at least one surface is coupled to another adjacent surface.

A plurality of battery packs are provided and may be coupled to each other by mechanical or electrical connection between the plurality of battery packs.

The plurality of battery packs can be stacked in a vertical direction.

The electrical connection between the plurality of battery packs may be a series connection such that the voltage ranges of the plurality of battery packs are regulated in various ways.

The electrical connection between the plurality of battery packs may be a parallel connection such that the power storage capacities of the plurality of battery packs are adjusted in various ways.

To achieve the above object, according to another aspect of the present disclosure, there is provided an energy storage system including one or more of the battery packs according to the present disclosure.

Advantageous effects

According to one aspect of the present disclosure, a battery pack having improved safety can be provided.

In particular, according to one embodiment of the present disclosure, even if a thermal event occurs inside the battery pack, it is possible to rapidly control the thermal event.

Also, when a problem such as thermal runaway or fire occurs in some of the plurality of battery cells included in the battery pack, it can effectively prevent the problem from being transferred to other modules.

Further, according to an aspect of the present disclosure, it is possible to provide a battery pack having a simple structure and enhanced thermal safety.

In particular, according to one embodiment of the present disclosure, since a new part is not required to be added to inject the fire extinguishing agent, it is possible to provide a battery pack that is excellent in manufacturability and has economical efficiency.

Furthermore, according to one aspect of the present disclosure, a design of a special waterproof and dustproof structure or the like is unnecessary.

Further, according to an aspect of the present disclosure, a plurality of battery packs of the same type are stacked, whereby products having various voltage ranges and/or power storage capacities can be provided.

In addition, various embodiments of the present disclosure are capable of achieving several other additional effects. Such different effects of the present disclosure will be described in detail in each embodiment, or a description of effects that can be easily understood by those skilled in the art will be omitted.

Drawings

The accompanying drawings illustrate preferred embodiments of the present disclosure, and together with the detailed description provided below, serve to provide a further understanding of the technical spirit of the present disclosure. Accordingly, the present disclosure is not to be construed as limited to those drawings.

Fig. 1 is an exploded perspective view schematically showing the configuration of a battery pack according to an embodiment of the present disclosure;

Fig. 2 is a view schematically showing a configuration in which a fire extinguishing agent is discharged from the battery pack of fig. 1;

fig. 3 is a perspective view schematically showing the configuration of a battery pack according to another embodiment of the present disclosure;

FIG. 4 is a cross-sectional view along line A4-A4' in FIG. 3;

Fig. 5 is an exploded perspective view schematically showing the configuration of a battery pack according to another embodiment of the present disclosure;

fig. 6 is a perspective view of a cell module assembly included in the battery pack of fig. 5;

Fig. 7 is a perspective view of a blocking member included in the battery pack of fig. 5;

FIG. 8 is an exploded perspective view of the blocking member of FIG. 7;

FIG. 9 is a top view of the blocking member of FIG. 7;

Fig. 10 is a perspective view of a battery pack case included in the battery pack of fig. 5;

fig. 11 and 12 are diagrams explaining a case in which a unit module assembly is received in the battery pack case of fig. 10;

FIG. 13 is a perspective view of a fire canister included in the battery pack of FIG. 5;

FIG. 14 is a perspective cross-sectional view of the fire canister of FIG. 13;

FIG. 15 is a top cross-sectional view of the lower coolant tank of the fire tank as viewed from above;

fig. 16 is a perspective view of a battery pack in which all the components of the battery pack described above with reference to fig. 5 to 15 are combined;

Fig. 17 is a perspective view schematically illustrating the battery pack of fig. 1 to 16; and

Fig. 18 and 19 are diagrams illustrating an embodiment in which battery cases shown in fig. 17 are stacked in different numbers from each other.

Detailed Description

The present disclosure will now be described in detail with reference to the accompanying drawings. Before the description, it should be understood that terms and words used in the specification and the appended claims should not be construed as having general and dictionary meanings, but interpreted as having meanings and concepts corresponding to technical ideas of the present disclosure in view of the principle that the inventors are able to properly define concepts of terms and words to properly describe themselves in the best manner.

Accordingly, the description set forth herein is merely for the purpose of illustrating preferred embodiments and is not intended to limit the scope of the present disclosure so that it will be understood that other equivalents and modifications may be made thereto without departing from the spirit and scope of the present disclosure.

Portions irrelevant to the description will be omitted to clearly describe the present disclosure, and like reference numerals denote like elements throughout the specification.

Further, in the drawings, the size and thickness of each element are arbitrarily illustrated for convenience of description, and the present disclosure is not necessarily limited to those illustrated in the drawings. In the drawings, the thickness of layers, regions, etc. are exaggerated for clarity. In the drawings, the thickness of portions and regions are exaggerated for convenience of description.

Furthermore, it will be understood that when an element such as a layer, film, region or panel is referred to as being "on" or "over" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, it means that there are no other intervening elements present. Further, the particular portion being "above" or "on" the reference portion means that the particular portion is "above" or "below" the reference portion and does not particularly mean that the particular portion is "above" or "on" toward the opposite direction of gravity. Meanwhile, similarly to the case where it is described as being disposed "on" or "over" another portion, the case where it is described as being disposed "under" or "under" another portion will also be understood with reference to the above-mentioned matters.

Furthermore, throughout this specification, when a portion is referred to as "comprising" or "including" a particular element, it means that the portion can further include other elements without excluding other elements unless the context requires otherwise.

Further, throughout this specification, when referred to as a "plane", this means that the target portion is viewed from the upper side, and when referred to as a "cross section", this means that the target portion is viewed from the side of the vertically cut cross section.

Fig. 1 is an exploded perspective view schematically showing the configuration of a battery pack according to an embodiment of the present disclosure.

Referring to fig. 1, a battery pack according to the present disclosure includes a cell module assembly 100, a battery pack case 300, and a fire canister 400.

The cell module assembly 100 may include one or more battery cells 110. Here, each battery cell 110 may mean a secondary battery. The secondary battery may include an electrode assembly, an electrolyte, and a battery case. In particular, the battery cells 110 disposed in the cell module assembly 100 may be pouch-type secondary batteries. However, other forms of secondary batteries, such as cylindrical batteries or prismatic batteries, may also be employed in the cell module assembly 100 of the present disclosure.

The plurality of secondary batteries may form the unit module assembly 100 in a form of being stacked one on another. That is, they may form the cell module assembly 100 in the form of a battery cell stack. For example, the plurality of battery cells 110 may be stacked in a form arranged in a horizontal direction (X-axis direction in the drawing) in a state in which each of the battery cells stands in a vertical direction (Z-axis direction in the drawing). Each of the battery cells 110 may include electrode leads, wherein the electrode leads may be located at both ends or at one end of each of the battery cells 110. A secondary battery in which an electrode lead protrudes in two directions may be referred to as a bi-directional cell, and a secondary battery in which an electrode lead protrudes in one direction may be referred to as a uni-directional cell. In fig. 1, a bi-directional monomer is shown.

However, the present disclosure is not limited to a specific type or form of the secondary battery, and various forms of secondary batteries known at the time of filing the present disclosure may be employed in the cell module assembly 100 of the present disclosure.

The battery pack case 300 may be configured to form an empty space inside and to accommodate the cell module assembly 100 in its inner space. For example, the battery pack case 300 may be configured in a box shape as shown in fig. 1. The pouch-shaped battery pack case 300 may be integrally formed, or may be manufactured such that at least one surface is coupled with an adjacent surface.

Fire canister 400 may store a fire suppressant. In particular, the fire tank 400 may have an interior space and store a fire extinguishing agent in the interior space. For example, the fire tank 400 may include a lower coolant tank 410 and an upper coolant tank cap 420 as shown in fig. 1. Here, the lower coolant tank 410 is configured in a box shape having an opened upper portion, and can provide a space capable of storing the fire extinguishing agent. Also, the upper coolant tank cover 420 may be configured to cover the upper opening portion of the lower coolant tank 410 and seal the fire extinguishing agent storage space of the lower coolant tank 410.

The fire canister 400 may be accommodated inside the battery pack case 300. In particular, the fire tank 400 may be disposed on the upper side of the cell module assembly 100 in the inner space of the battery pack case 300.

According to this configuration of the embodiment of the present disclosure, the fire extinguishing agent is discharged from the fire tank 400 located on the upper side of the unit module assembly 100, so that the thermal event of the unit module assembly 100 can be more easily controlled. In particular, the fire extinguishing agent discharged from the fire tank 400 can be easily moved downward by gravity. Accordingly, the fire extinguishing agent can more easily suppress heat and fire in the unit module assembly 100.

In particular, as shown in fig. 1, in the case where the cell module assembly 100 includes a plurality of battery cells 110 arranged horizontally, i.e., in the left-right direction (X-axis direction), if the fire extinguishing agent is discharged from the fire-extinguishing tank 400 located at the upper portion, the fire extinguishing agent can be easily supplied to all the battery cells 110. Thus, according to such an embodiment, thermal event suppression for the entire unitary module assembly 100 can be more effectively achieved.

The fire tank 400 may be configured to discharge the fire extinguishing agent toward the unit module assembly 100 when heat is applied from the unit module assembly 100. This will be described in more detail with reference to fig. 2.

Fig. 2 is a view schematically showing a configuration in which a fire extinguishing agent is discharged from the battery pack of fig. 1.

Referring to fig. 2, a fire tank 400 is located in an upper portion of the single module assembly 100. Among the plurality of battery modules stacked in the left-right direction (e.g., the X-axis direction in the drawing), as indicated by A1, a thermal event such as overheating, ignition, or thermal runaway in a specific battery cell 110 can occur. In this case, heat generated in the battery cell 110 may be applied to the fire-fighting tank 400 side, for example, as indicated by A2 in fig. 2. Then, in the fire tank 400, the fire extinguishing agent can be discharged as indicated by an arrow A3.

In particular, at least a portion of the fire tank 400 may be melted by heat applied from the cell module assembly 100. For example, in the configuration of fig. 2, the portion of fire canister 400 indicated by A2 may be melted by heat. Then, by melting the portion, the extinguishing agent can be discharged as indicated by arrow A3.

To this end, at least a portion of the fire tank 400 may be made of a material that can be melted by heat applied from the monomer module assembly 100. For example, the fire canister 400 may be entirely made of a plastic material. In particular, the fire canister 400 may be configured in the form of plastic injection molding.

In addition, the fire tank 400 may be configured to be melted by ventilation gas or heat sprayed from the battery cell 110. For example, when thermal runaway occurs in the battery cell 110 and the ventilation gas is injected, the ventilation gas may be in a high temperature state of a constant temperature or higher. The fire canister 400 may be configured from materials and/or forms that are capable of being melted by such high Wen Tongqi gas. Alternatively, when thermal runaway occurs in the battery cell 110, the battery cell 110 may be at a higher temperature than in the normal state even if the ventilation gas is not injected. The fire tank 400 may be configured from a material and/or form that is capable of being melted by heat applied from the battery cells 110 in an abnormally high temperature state.

In particular, the fire canister 400 may be configured such that the base plate 411 is melted by heat generated during an event of the battery cell 110 and/or high temperature of the gas. In this case, the fire extinguishing agent may flow into the melted bottom of the fire tank 400 and be discharged in a downward direction. Thus, the fire extinguishing agent can be rapidly injected into the single module assembly 100 side.

According to this configuration of the embodiments of the present disclosure, the fire extinguishing agent is injected in such a manner that the injection material melts, so that thermal events inside the battery pack can be effectively suppressed, and thermal event propagation between the battery cells 110 can be minimized.

The fire tank 400 may store the fire extinguishing agent in a liquid state. In this case, the fire extinguishing agent may be referred to as a fire extinguishing fluid. For example, the fire tank 400 may store water or other coolant as a fire suppressant. In addition, the fire tank 400 may store an antifreeze solution as a fire extinguishing agent. In particular, when the battery pack is used in a cold season such as winter season or in a low temperature region such as arctic region, the fire-fighting tank 400 may store an antifreeze solution that is not easily frozen even at low temperature as a fire extinguishing agent. Also, in the case of a home battery pack, since it can be located outdoors, an antifreeze solution can be provided as a fire extinguishing agent.

The fire canister 400 may be configured such that the thickness of the base 411 is different for each location. This will be described in more detail with reference to fig. 3 and 4.

Fig. 3 is a perspective view schematically showing the configuration of a battery pack according to another embodiment of the present disclosure. However, in fig. 3, a part of the configuration is shown in a transparent manner for convenience of explanation. Further, fig. 4 is a sectional view along a line A4-A4' in fig. 3. For various embodiments (including this embodiment) included in the present specification, detailed descriptions of portions in which portions described in other embodiments can be identically or similarly applied thereto will be omitted, and portions having differences will be mainly described.

Referring to fig. 3 and 4, the fire tank 400 may include a base 411 and a sidewall 412. Here, the sidewall 412 may be configured to protrude upward from a corner of the base plate 411. In addition, the fire tank 400 can be limited at a lower portion and a side portion by the base plate 411 and the side wall 412 to form a space capable of storing the fire extinguishing agent. At this time, the upper portion of the fire pot 400 may be sealed by the battery pack case 300. That is, as shown in fig. 4, the battery pack case 300 includes a lower case 300a and an upper case 300b, wherein the upper portion of the fire-fighting tank 400 is covered by the upper case 300b so that the fire extinguishing agent can be retained inside the fire-fighting tank 400. Alternatively, the fire tank 400 may be configured to include an upper coolant tank cap 420 and seal an upper portion of the fire suppressant storage space as shown in fig. 1.

In the configuration of the fire tank 400 provided with the base plate 411 in this way, the base plate 411 may be formed with a different thickness for each portion. In particular, the fire tank 400 may be configured to have a reduced thickness in certain portions, such as the portion indicated by 411a in fig. 3 and 4. For example, the base plate 411 of the fire canister 400 may be configured in the form of plastic injection molding having a thickness of 1mm as a whole, but a portion indicated by 411a may be configured to have a thickness of 0.5 mm.

In particular, the portion of the base plate 411 of the fire canister 400 having a thin thickness therein may functionally serve as the frangible portion 411a. That is, when the temperature of the unit module assembly 100 increases, the fragile portion 411a may be broken first. Also, when the fragile part 411a is broken, the fire extinguishing agent stored in the fire tank 400 may be discharged toward the unit module assembly 100 through the fragile part 411a.

A plurality of fragile portions 411a may be provided. The fragile portion 411a may have, for example, a shape in which the width is narrow and the length is long. That is, it may have a linear shape, which is a linear shape arranged parallel to one end of the fire-fighting tank 400, and the fragile portions 411a may be arranged parallel to each other.

According to this embodiment, when ventilation gas, fire, etc., due to thermal runaway occur on the side of the unit module assembly 100, it is not necessary to separately provide a structure for injecting a fire extinguishing agent such as cooling water. Therefore, the arrangement for introducing the fire extinguishing agent inside the battery pack can be realized with a simple structure. Also, in this configuration, since the fire extinguishing agent can be discharged through the fragile portion 411a having a thin thickness when an event occurs, a portion from which the fire extinguishing agent is discharged can be specified in advance.

In the above embodiment, the plurality of fragile portions 411a may be provided in one fire tank 400 as shown in fig. 4. Further, the plurality of fragile parts 411a may be placed on the base plate 411 of the fire tank 400 to be separated from each other by a predetermined distance along the stacking direction of the unit module assemblies 100. For example, in the cell module assembly 100, the plurality of battery cells 110 may be stacked in the left-right direction (X-axis direction). In the base plate 411 of the fire tank 400 on the upper portion of the unit module assembly 100, a plurality of fragile portions may be placed in the left-right direction while being spaced apart from each other.

In particular, the fire-fighting tank 400 may be configured such that the fragile portion 411a having a relatively thin thickness is located in a central portion between the cells stacked in the horizontal direction.

For example, in the configuration of fig. 4, two battery cells 110, i.e., B1 and B2, are disposed adjacent to each other in the left-right direction in the left portion of the cell module assembly 100. At this time, the fragile portion 411a located on the leftmost side among the plurality of fragile portions 411a may be disposed between B1 and B2 in the left-right direction. That is, it can be said that the fragile portion 411a is located above B1 and B2 in the vertical direction (Z axis direction), but is located between B1 and B2 in the horizontal direction (X axis direction). Further, the battery cells 110 other than B1 and B2 may be configured such that one fragile part 411a for every two adjacent battery cells 110 is located in the space therebetween in the horizontal direction.

According to such a configuration of the embodiment of the present disclosure, when a thermal event occurs in a specific battery cell 110 and heat is applied to the upper fragile part 411a, the fragile part 411a may be broken. Then, the fire extinguishing agent is discharged through the broken fragile portion 411a, and the fire extinguishing agent can flow into the space between the adjacent battery cells 110 as indicated by arrows in fig. 4.

Therefore, according to such an embodiment, the transfer of thermal events between the battery cells 110 can be more effectively prevented. In addition, according to the embodiments of the present disclosure, since the fire extinguishing agent can be injected intensively around the battery cell 110 where a thermal event such as overheating or ignition has occurred, more efficient cooling and fire extinguishing operations can be performed. Thus, according to this embodiment, when a fire or the like occurs inside the battery, it is possible to inject the fire extinguishing agent in an appropriate position at the right time without any other portion than the fire tank 400.

Fig. 5 is an exploded perspective view schematically showing the configuration of a battery pack according to another embodiment of the present disclosure.

Referring to fig. 5, the battery pack includes a cell module assembly 100, a blocking member 200, a battery pack case 300, a fire-fighting pot 400, an outer cap 500, and an electrical connection unit 600.

Even in fig. 5, the cell module assembly 100 may be configured such that each of the plurality of battery cells 110 is stacked in a form arranged along a horizontal direction (e.g., an X-axis direction in the drawing) in a state of being erected in a vertical direction (e.g., a Z-axis direction in the drawing). At this time, the longitudinal direction of the battery cell 110 is, for example, the Y-axis direction in the drawing.

Fig. 6 is a perspective view of a unit module assembly 100 included in the battery pack of fig. 5.

For reference, in order to more clearly illustrate the components included in the cell module assembly 100, fig. 6 illustrates the remaining components except for the plurality of battery cells 110. The plurality of battery cells 110 may be conventional pouch-type battery cells or prismatic battery cells.

Referring to fig. 6, a pair of bus bar covers 130 are disposed on the front and rear surfaces of the stack of the plurality of battery cells 110. Each of the bus bar covers 130 is disposed in a direction (e.g., an X-axis direction in the drawing) orthogonal to the longitudinal direction of the battery cell 110.

A pair of end plates 120 are respectively disposed at both side ends of the stack of the plurality of battery cells 110. The end plate 120 is disposed parallel to the battery cells 110. A pair of end plates 120 are respectively connected between the pair of bus bar housings 130.

Each of the upper and lower sides between the pair of end plates 120 may include at least one strap 140 connected between the pair of end plates 120. The straps 140 strengthen the bond of the unitary module assembly 100. More specifically, it reinforces the coupling of the pair of end plates 120 and the stack of the plurality of battery cells 110 disposed therebetween. This can prevent the stack of the battery cells 110 from being displaced.

In addition, the description regarding the unitary module assembly 100 is repeated with those described in fig. 1, and thus, for details, reference is made to those described above with reference to fig. 1.

Meanwhile, as shown in fig. 5, the plurality of battery cells 110 may be grouped and accommodated in a predetermined number. Also, as shown in fig. 5 to 9, the blocking member 200 is disposed between a group of a plurality (predetermined number) of battery cells 110 and a group of a plurality (predetermined number) of adjacent battery cells 110.

Fig. 7 is a perspective view of a blocking member 200 included in the battery pack of fig. 5. Fig. 8 is an exploded perspective view of the blocking member 200 of fig. 7. Fig. 9 is a top view of the blocking member 200 of fig. 7.

The blocking member 200 may be configured to be interposed between adjacent battery cells 110 to block heat. For example, when a thermal event occurs in some of the battery cells 110 to generate heat or high Wen Tongqi gas, the blocking member 200 may inhibit or block the generated heat or gas from being transferred to an adjacent battery cell 110. In addition, the blocking member 200 may be used to block flames or sparks sprayed from a specific battery cell 110.

The blocking member 200 has a substantially plate-like shape. The blocking member 200 may be configured in a plate shape erected in a vertical direction. Also, the blocking member 200 may also have a height equal to or similar to that of the battery cell 110 erected in the vertical direction. The height of the blocking member 200 may be smaller or larger than the height of the battery cell 110.

A plurality of blocking members 200 may be included according to the number of battery cells. Also, as described above, the blocking member 200 may constitute the cell module assembly 100 in a stacked form together with the battery cells 110.

According to this configuration of the embodiment of the present disclosure, in the battery pack including the plurality of battery cells 110, the blocking member 200 can effectively prevent thermal runaway propagation or the like between the cells.

Also, the blocking member 200 may be largely formed of a triple structure. For example, a pair of bump pads 220 are provided on each of both surfaces of the support plate 210. The support plates 210 maintain the shape and rigidity of the blocking member 200 and block flames or sparks sprayed from the battery cells 110 between the battery cells 110. The support plate 210 may be made of, for example, a metal material. The bump spacer 220 reduces the pressure applied to the battery cell 110 due to the support plate 210 during the bump of the battery cell 110. The bump pad 220 may be made of, for example, a silicone material or a soft plastic material.

Meanwhile, the support plate 210 includes a plurality of through holes 230 formed by passing through the support plate 210 in a vertical direction as shown in detail in fig. 9, and the plurality of through holes 230 are disposed along a longitudinal direction of the support plate 210.

When the fire extinguishing agent (fire extinguishing fluid) is injected into the unit module assembly 100 from the fire-extinguishing tank 400 located in the upper portion of the unit module assembly 100, the fire extinguishing agent (fire extinguishing fluid) even enters the plurality of through holes 230. That is, since the extinguishing agent (extinguishing fluid) stays in the plurality of through holes 230, the battery cells 110 in which a thermal event has occurred can be more effectively cooled and extinguish the fire.

The plurality of through holes 230 may be formed to be opened on both upper and lower surfaces of the support plate 210. Alternatively, the plurality of through holes 230 are opened only in the upper surface thereof, and the lower surface thereof may have a blocking shape so that the extinguishing agent (extinguishing fluid) can stay in the through holes 230 for a longer period. In the former case, if the support plate 210 of the blocking member 200 is placed to be tightly adhered to the inner lower surface of the battery pack case 300, the fire extinguishing agent (fire extinguishing fluid) may stay in the through-hole 230 longer as in the latter case.

Fig. 10 is a perspective view of a battery pack case 300 included in the battery pack of fig. 5. Fig. 11 and 12 are diagrams explaining a case in which the cell module assembly 100 is received in the battery pack case 300 of fig. 10.

Referring to fig. 10, the battery pack case 300 may be configured in a box shape. The pouch-shaped battery pack case 300 may be integrally molded, or may be manufactured such that at least one surface is coupled with an adjacent surface.

The battery pack housing 300 includes at least one vent 320. The filter is mounted on the vent 320.

When a thermal event occurs in the battery cells 110 accommodated inside the battery pack case 300, the vent gas generated from the corresponding battery cells 110 may be discharged through the vent holes 320. The vent gas discharged from the vent hole 320 may pass through a space (see fig. 5) between the battery pack case 300 and the outer cover 500 and be discharged to the outside of the outer cover 500.

Meanwhile, as shown in fig. 11 and 12, the unit module assembly 100 shown in fig. 6 may be received in the inner space of the auxiliary case 310 and then mounted on the battery pack case 300. The cell module assembly 100 is initially received in the inner space of the auxiliary housing 310 and then is finally received in the battery pack housing 300, whereby it is possible to supplement the rigidity of the cell module assembly 100 and prevent the misalignment of the stacks of the plurality of battery cells 110 in the cell module assembly 100. The auxiliary housing 310 may be made of, for example, metal, stainless steel, or the like.

Fig. 13 is a perspective view of a fire canister 400 included in the battery pack of fig. 5. Fig. 14 is a perspective cross-sectional view of the fire tank 400 of fig. 13 and shows a cross-section taken along line A5-A5' in fig. 5. Fig. 15 is a top cross-sectional view of the lower coolant tank 410 of the fire tank 400 as viewed from above.

As described above in fig. 1, the fire tank 400 includes a lower coolant tank 410 and an upper coolant tank cap 420. The lower coolant tank 410 and the upper coolant tank cover 420 may be separately manufactured and hermetically coupled, or may be integrally manufactured. The upper coolant tank cap 420 may further include an inlet port 430 capable of injecting fire suppressant. The inlet port 430 may be closed with a plug to seal the fire canister 400.

A portion of the base plate 411 where the lower coolant tank 410 is formed to be thin can function as the fragile portion 411a. That is, when a thermal event occurs in the battery cells 110 of the cell module assembly 100, this fragile portion 411a, where the thickness is relatively thin, may be broken first. When the fragile part 411a is broken to form an opening in the base plate 411, the fire extinguishing agent stored inside the fire tank 400 may be discharged toward the unit module assembly 100 through the corresponding fragile part 411a.

A plurality of fragile portions 411a may be provided. The fragile portion 411a may have, for example, a shape in which the width is narrow and the length is long. That is, it may have a linear shape, which is a linear shape arranged parallel to one end of the fire-fighting tank 400, and the fragile portions 411a may be arranged parallel to each other.

Meanwhile, according to the present embodiment, the longitudinal direction (e.g., the X-axis direction in the drawing) of the battery cell 110 and the longitudinal direction (e.g., the X-axis direction in the drawing) of the fragile part 411a may be orthogonal to each other. That is, the plurality of fragile parts 411a are disposed to cross the longitudinal direction of the corresponding battery cell 110. Thereby, the fire extinguishing agent can be supplied all at once through the plurality of open fragile parts 411a throughout the battery cell 110 in the longitudinal direction of the battery cell 110 where the thermal event has occurred, and the battery cell 110 where the thermal event has occurred can be extinguished more efficiently and rapidly.

Further, referring to fig. 14, the base plate 411 of the lower coolant tank 410 has a step difference. More specifically, the substrate 411 is largely classified as follows. It is composed of a portion A7 where the fragile part 411a is located, a portion A8 adjoining on the band 140 of the battery pack case 100, and a portion A9 located on the side of the electrical connection unit 600. Among them, the substrate 411 is lowest in height at a portion A7 where the fragile portion 411a is located.

The fragile part 411a of the lower coolant can 410 is disposed as closest to the battery cell 110 as possible. Thus, when an overheat or fire condition has occurred in some of the battery cells 110, rapid initial suppression can be performed, thereby more effectively preventing dangerous conditions such as secondary explosion from occurring due to heat or flame transfer to the adjacent battery cells 100.

In addition, as shown in fig. 6 with respect to the cell module assembly 100, the height of the cell module assembly 100 is not constant due to a portion where the tape 140 is located, a portion where the bus bar cover 130 is located, or the like. Independently of this, if the height of the base plate 411 of the lower coolant tank 410 of the fire tank 400 is constant as a whole, an empty space is relatively created between the base plate 411 of the fire tank 400 and the upper surface of the unit module assembly 100. In this case, heat transfer from the battery cell 110, the temperature of which has been raised, to the fragile part 411a is hindered by the empty space, so that fire extinguishing is delayed only thereby.

When the battery cell 110 is overheated, the fragile part 411a is placed next to the battery cell 110 whose temperature has risen, so that the fragile part 411a is instantaneously broken, and the battery cell 110 can be rapidly cooled and extinguished.

In summary, the lower surface of the base plate 411 of the fire tank 400 and the upper surface of the unit module assembly 100 have shapes substantially conforming to each other. Thus, since the fire-fighting tank 400 is disposed in closer contact with the cell module assembly 100, it is thereby possible to more effectively cool the battery cells 110 having an increased temperature, and to more rapidly inject the fire extinguishing agent into the battery cells 110 where overheating or ignition occurs. In addition, the fire extinguishing agent can be efficiently contained in the fire tank 400. That is, if the height of the base plate 411 of the lower coolant tank 410 of the fire tank 400 is constant as a whole, the fire tank 400 contains as little fire extinguishing agent as the corresponding empty space.

The fire extinguishing agent disposed in the fire tank 400 may, for example, be in the form of a fire extinguishing fluid, and redundant description is omitted. For details, reference is made to those described above.

Fig. 16 is a perspective view of a battery pack in which all the components of the battery pack described above with reference to fig. 5 to 15 are combined.

In addition, for portions where the description herein regarding the battery packs of fig. 5 to 16 is repeated with the description regarding the battery packs of fig. 1 to 4, reference is made to those described above in fig. 1 to 4.

Meanwhile, a plurality of battery cases 300 may be provided and they are configured to be stacked in the vertical direction. This will be described in more detail with reference to fig. 17.

Fig. 17 is a perspective view schematically showing at least a part of the configuration of the battery pack of fig. 1 to 16 of the present disclosure. Also, fig. 18 and 19 are diagrams illustrating an embodiment in which a plurality of battery cases 300 shown in fig. 17 are stacked.

Referring to fig. 17, the battery pack case 300 may include a bottom portion and a sidewall portion. The cell module assembly 100 can be received in the inner space of the battery pack case 300, and the upper surface of the cell module assembly 100 is covered by the fire-fighting pot 400 to form a battery pack. For reference, in fig. 17, the height of the upper side of the battery pack case 300 is shown to be greater than the height of the upper surface of the fire-fighting tank 400. However, fig. 17 is only a schematic diagram and one exemplary embodiment, and the present disclosure is not limited to those shown in fig. 17. That is, on the contrary, various modifications and changes can be made, for example, the height of the upper surface of the fire-fighting tank 400 may be greater than the height of the upper side of the battery pack case 300, and the height of the upper surface of the fire-fighting tank 400 and the height of the upper side of the battery pack case 300 may be equal.

The battery pack case 300 as shown in fig. 17 may be formed of a plurality of battery pack cases 300, so that a stacked structure of battery packs can be formed as shown in fig. 18 or 19. At this time, the battery pack of fig. 17 may be one unit pack. In addition, since such a unit group is formed of a plurality of units, the entire battery pack, as shown in fig. 18 or 19, in which modules are stacked, may be configured.

More specifically, for example, in the configuration of fig. 18, a shape in which three cell groups D are stacked in the vertical direction is illustrated. Also, in the configuration of fig. 19, a shape in which five cell groups D are stacked in the vertical direction is illustrated. The present disclosure is not limited to those illustrated, and may be implemented by changing the number of the cell groups D in various ways to suit the environment in which the present invention is implemented.

For example, if the battery pack of the present disclosure is implemented as an Energy Storage System (ESS), the number of cell battery packs is adjusted so that the voltage range and/or power storage capacity of the energy storage system can be implemented as appropriate for its environment. According to such a configuration of the embodiments of the present disclosure, the single cell groups having a common structure are stacked in various ways, which enables coping with products of various voltage ranges and/or power storage capacities according to the number of stacks. For example, by adjusting the number of stacks of the same cell group, a low-pressure product as shown in fig. 18, or a high-pressure product as shown in fig. 19 can be realized. Therefore, economic efficiency or compatibility can be improved as compared with a standard product limited only to a specific voltage range. In addition, according to this configuration of the embodiment, products having various capacities can be realized.

In other words, if the cell groups to be stacked are connected in series, products of various voltage ranges can be realized according to the number of stacks. Further, when the unit groups to be stacked are connected in parallel, products of various capacities (electric power storage capacities) can be realized according to the number of stacks.

In particular, each cell group D may have a single module assembly 100 therein. In addition, as described above, each unit group D includes the connector 610 so as to electrically connect each unit module assembly 100 to each other during stacking. In particular, due to the stacking of each cell group D on top of each other, these connectors 610 may be configured to couple with each other.

Also, in this configuration of the embodiment, the fire tank 400 may be accommodated in each of the cell groups D together with the unit module assemblies 100. That is, as described above, each unit group D includes the fire tank 400 on the upper portion of the cell module assembly 100. The plurality of stacked battery packs have a stacked structure of fire-fighting pot 400-cell module assembly 100-fire-fighting pot 400-cell module assembly 100 from top to bottom. The stacked battery pack of the present disclosure having such a structure allows the battery pack to be configured by increasing (expanding) the number of cell module assemblies 100 to increase various voltage ranges and/or power storage capacities, and also to safely cope with thermal events such as fires of the cell module assemblies 100. Therefore, according to this embodiment of the present disclosure, the safety of the battery pack can be further improved.

In another example of the coupling method between vertically stacked battery packs (battery pack case 300), referring again to fig. 17, the details are as follows. At the upper end of the sidewall part of the battery pack case 300, there may be a step formed concavely inward, such as a step C1 for coupling. For example, the thickness of the side wall portion of the battery pack case 300 becomes a thin portion. In addition, although not shown in fig. 17, a concave portion for coupling may be formed at the bottom of the battery pack case 300 such that a stepped portion C1 for coupling of the sidewall portion is inserted. That is, when the battery pack cases 300, which are different from each other, are stacked in the vertical direction, the battery pack case 300 may be configured such that the coupling stepped part C1 formed on the upper side of the sidewall part of the lower battery pack case 300 is inserted into the coupling concave part formed on the bottom of the upper battery pack case 300. Thus, when the plurality of battery cases 300 are stacked and coupled in the vertical direction, the outer surface of the battery case 300 may have a flat shape as a whole.

Meanwhile, the coupling methods for the fastening structure between the vertically stacked battery packs are not limited to those shown in fig. 17 and/or 10, and other various coupling methods can be modified or changed and thus applied to the present disclosure.

In addition, the battery pack of the present disclosure can be connected to a battery management system (BMS, not shown). The battery management system monitors and manages the battery pack. The battery management system may be located on the uppermost layer of the vertically stacked battery packs. However, the location of the battery management system is not limited to the above, and can be variously modified or changed according to a method or environment in which the present invention is implemented.

In addition to the above-described components, the battery pack according to the present disclosure may further include various other components included in the battery pack. For example, a battery pack according to the present disclosure may include various electrical components for controlling or managing charge and discharge of the battery pack, such as a Battery Management System (BMS), a relay, a fuse, and a current sensor.

An Energy Storage System (ESS) according to the present disclosure includes one or more battery packs according to the present disclosure as described above. In addition, the energy storage system according to the present disclosure may further include general components included in the energy storage system, in addition to the battery pack.

Meanwhile, terms representing directions such as front side, rear side, left side, right side, upper side and lower side have been used in the embodiments of the present disclosure, but it is apparent to those skilled in the art that the terms used are provided for convenience of description only and may be changed according to the position of an object, the position of an observer, and the like.

While the present disclosure has been particularly shown and described with reference to exemplary embodiments and the accompanying drawings, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Description of the reference numerals

100: Single module assembly

110: Battery cell

120: End plate

130: Bus bar cover

140: Belt with a belt body

200: Barrier member

210: Supporting plate

220: Bump pad

230: Through hole

300: Battery pack case

300A: lower shell

300B: upper shell

310: Auxiliary shell

320: Vent hole

400: Fire-fighting pot

410: Lower coolant tank

411: Substrate board

411A: frangible portion

412: Side wall

420: Upper coolant tank cover

430: Inlet port

500: Outer cover

600: Electrical connection unit

610: A connector.

Claims (16)

1. A battery pack, comprising:

A cell module assembly including a cell stack in which a plurality of battery cells are stacked;

a battery pack housing configured to house the cell module assembly and open at an upper surface of the battery pack housing; and

A fire fighting pot located above the unit module assembly and covering the battery pack case,

Wherein, the fire-fighting pot includes:

An interior space containing a fire extinguishing agent; and

A plurality of fragile parts, which are relatively thin portions of the base plate of the fire tank, and are melted and opened by a thermal event of the battery cell.

2. The battery pack of claim 1, wherein:

the frangible portions have a linear shape and are arranged parallel to one edge of the fire-fighting tank, the respective frangible portions are arranged parallel to each other, and

The longitudinal direction of the fragile part and the longitudinal direction of the battery cell are orthogonal to each other.

3. The battery pack of claim 1, wherein:

the frangible portions have a linear shape and are arranged parallel to one edge of the fire canister, the respective frangible portions are arranged parallel to each other,

The longitudinal direction of the fragile part and the longitudinal direction of the battery cell are parallel to each other, and

The fragile part is disposed between two battery cells adjacent to each other.

4. The battery pack of claim 1, wherein:

The fire fighting pot is made by plastic injection moulding.

5. The battery pack of claim 1, wherein:

The base plate of the fire canister has a step difference, and a portion where the plurality of fragile portions are placed has a lowest height.

6. The battery pack of claim 1, wherein:

the single module assembly includes:

a pair of bus bar covers disposed on front and rear surfaces of the battery cell stack; and

A pair of end plates disposed parallel to the battery cells at both ends of the battery cell stack,

Wherein the pair of end plates are connected between the pair of bus bar housings.

7. The battery pack of claim 6, wherein:

the single module assembly includes:

And a band connecting upper and lower sides of the pair of end plates of the battery cell stack, thereby reinforcing the coupling of the cell module assemblies.

8. The battery pack of claim 7, wherein:

the substrate has a step difference, and a height of a portion where the plurality of fragile portions are placed is lower than a height of a portion placed on the belt.

9. The battery pack of claim 1, further comprising:

a plate-shaped blocking member disposed between adjacent battery cells,

Wherein the blocking member includes a support plate and a pair of bump pads provided on both surfaces of the support plate.

10. The battery pack of claim 1, wherein:

The fire extinguishing agent is a liquid fire extinguishing agent.

11. The battery pack of claim 1, wherein:

The battery pack case is made of a box shape having an opened upper surface, and

The battery pack housing is integrally formed or manufactured such that at least one surface is coupled to another adjacent surface.

12. The battery pack of claim 1, wherein:

A plurality of battery packs are arranged, and

The plurality of battery packs are coupled to each other by mechanical or electrical connection therebetween.

13. The battery pack of claim 12, wherein:

the plurality of battery packs can be stacked in a vertical direction.

14. The battery pack of claim 12, wherein:

the electrical connections between the plurality of battery packs are connected in series so that the voltage ranges of the plurality of battery packs are regulated in various ways.

15. The battery pack of claim 12, wherein:

the electrical connections between the plurality of battery packs are connected in parallel, so that the electric power storage capacities of the plurality of battery packs are adjusted in various ways.

16. An energy storage system comprising the battery pack of claim 1.