Battery module having a structure capable of quickly calling a sprinkler and energy storage system including the battery module

Abstract

A battery module according to one embodiment of the present invention includes: a plurality of battery cells; a module housing configured to accommodate a cell stack including the plurality of battery cells; a sprayer that passes through the module housing from one side in a stacking direction of the cell stack; and at least one guide plate that is fixed to an interior of the module housing and is installed obliquely so that one longitudinal end of the at least one guide plate faces the sprayer.

Description

Technical Field

[0001] The present disclosure relates to a battery module having a structure allowing quick operation of a sprinkler and an ESS including the battery module, and more particularly, to a battery module having a structure allowing quick operation of a sprinkler by guiding high-temperature gas to move intensively toward a glass bubble provided to the sprinkler when exhaust gas leaks into the interior of the battery module and an ESS including the battery module.

[0002] This application claims priority from Korean Patent Application No. 10-2020-0024460 filed in Korea on February 27, 2020, the disclosure of which is incorporated herein by reference. Background Art

[0003] Currently commercialized secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries and lithium secondary batteries. Among them, lithium secondary batteries have attracted much attention because they have almost no memory effect compared to nickel-based secondary batteries, thus ensuring free charging and discharging, and also have very low discharge rates and high energy density.

[0004] Lithium secondary batteries mainly use lithium oxides and carbon materials as positive electrode active materials and negative electrode active materials, respectively. Lithium secondary batteries include: an electrode assembly in which a positive electrode plate and a negative electrode plate coated with positive electrode active materials and negative electrode active materials are provided, respectively, and a separator is placed between the positive electrode plate and the negative electrode plate; and an exterior, i.e., a battery bag exterior, which is used to seal and store the electrode assembly together with the electrolyte.

[0005] Recently, secondary batteries are widely used not only in small devices such as portable electronic devices, but also in medium or large devices such as vehicles and energy storage systems. When used in such medium or large devices, a large number of secondary batteries are electrically connected to increase capacity and output. In particular, pouch-type secondary batteries are widely used in such medium-sized devices because pouch-type secondary batteries can be easily stacked.

[0006] Meanwhile, as the demand for large-capacity structures has recently increased with the use as energy storage sources, the demand for battery modules including a plurality of secondary batteries electrically connected in series and / or in parallel has also increased.

[0007] In addition, the battery module generally has an outer case made of a metal material to protect or store a plurality of secondary batteries from external impacts. Meanwhile, the demand for high-capacity battery modules is recently increasing.

[0008] In the case of such a high-capacity battery module, if the temperature inside the battery module increases due to degassing in at least some of the internal battery cells, great damage may occur. That is, if a thermal runaway phenomenon occurs due to the increase in internal temperature, the temperature of the high-capacity battery module may increase rapidly, and thus a large-scale fire and / or explosion may occur.

[0009] Therefore, there is a need to develop a rapid and complete fire extinguishing technology to take immediate measures when an abnormal temperature rise occurs due to exhaust gas in the battery cells inside the battery module. Summary of the invention

[0010] Technical issues

[0011] The present disclosure is designed to solve the problems of the related art, and thus the present disclosure is directed to allowing a quick operation of a sprinkler by guiding the high-temperature exhaust gas to move intensively toward a glass bubble provided to the sprinkler when the high-temperature exhaust gas leaks to the inside of a battery module.

[0012] However, the technical problems to be solved by the present disclosure are not limited to the above contents, and those skilled in the art will understand other purposes not mentioned herein based on the following description.

[0013] Technical Solution

[0014] In one aspect of the present disclosure, a battery module is provided, comprising: a plurality of battery cells; a module housing configured to accommodate a cell stack comprising the plurality of battery cells; a sprayer disposed to pass through the module housing at one side in a stacking direction of the cell stack; and at least one guide plate fixed to an interior of the module housing and installed obliquely so that one longitudinal end of the at least one guide plate is oriented toward the sprayer.

[0015] The module housing may include: a pair of base covers, which are configured to cover the lower surface and the upper surface of the cell stack, respectively; a pair of side covers, which are configured to cover the side surfaces of the cell stack; a front cover, which is configured to cover the front surface of the cell stack; and a rear cover, which is configured to cover the rear surface of the cell stack.

[0016] The guide plate may be configured to protrude from an inner surface of the side cover toward the cell stack.

[0017] The battery module may include a pair of bus bar frames respectively coupled to one side and the other side of the cell stack in a width direction.

[0018] The sprayer may be provided to pass through one longitudinal side of the rear cover and be located in a hollow space formed between the bus bar frame and the side cover.

[0019] The sprinkler may include: a connector located at an outer side of the module housing and connected to a supply pipe that supplies a cooling fluid; a sprinkler head located at an inner side of the module housing and connected to the connector; and an insulating cover configured to cover the sprinkler head.

[0020] The sprayer head may include: a glass bubble, which is configured to block a cooling fluid injection hole of the connector and is configured to: when the temperature or flow rate of the gas inside the battery module increases beyond a reference value, the glass bubble is broken to open the cooling fluid injection hole; and a retaining bracket, which is configured to fix the glass bubble while surrounding the glass bubble.

[0021] The insulating cover may include a first region facing the cell stack and the busbar frame, the first region may be formed such that a closed area is larger than an open area, and a second region other than the first region may be formed such that an open area is larger than a closed area.

[0022] The first region may have at least one cover hole for injecting a cooling fluid.

[0023] The battery module may include: an air inlet formed to pass through the front cover; an air outlet formed to pass through the rear cover; and an expansion pad disposed at an inner side of the air inlet and the air outlet and configured to at least partially close the air inlet and the air outlet by expanding when in contact with a cooling fluid introduced into the battery module.

[0024] The expansion pad may be attached to an inner surface of the module housing.

[0025] The expansion pad may be at least partially inserted into an accommodation groove formed at an inner surface of the module case.

[0026] The battery module may include mesh plates respectively disposed at both sides of the expansion pad to guide expansion movement of the expansion pad.

[0027] The air inlet and the air outlet may be formed at positions corresponding to a hollow space formed between the bus bar frame and the side cover.

[0028] Meanwhile, an energy storage system (ESS) according to an embodiment of the present disclosure includes a plurality of battery modules according to the present disclosure.

[0029] Beneficial Effects

[0030] According to an embodiment of the present disclosure, when high-temperature exhaust gas leaks into the interior of the battery module, the high-temperature exhaust gas can move centrally toward the glass bubble provided to the sprinkler, so that the sprinkler can operate quickly, thereby preventing fire and / or explosion caused by thermal runaway phenomenon. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are used to provide a further understanding of the technical features of the present disclosure. Therefore, the present disclosure is not interpreted as being limited to the accompanying drawings.

[0032] Figure 1 and Figure 2 is a perspective view showing a battery module according to an embodiment of the present disclosure.

[0033] Figure 3 It is shown Figure 1 and Figure 2 A view of the internal structure of a battery module shown in FIG.

[0034] Figure 4 and Figure 5 is a view showing an internal structure of a battery module according to an embodiment of the present disclosure to demonstrate a sprayer applied in the present disclosure.

[0035] Figure 6 is a perspective view showing an insulating cover applied in the present disclosure.

[0036] Figure 7 is a view showing the internal structure of a side plate applied in the present disclosure.

[0037] Figure 8 is a perspective view showing an insulating cover used in the present disclosure, the insulating cover and Figure 6 The insulating cover shown in is different.

[0038] Fig. 9 It is shown Figure 8 A front view of the insulating cover shown in FIG.

[0039] Fig.10 is a view showing the positional relationship of an insulating cover and a guide plate applied in the present disclosure.

[0040] Fig.11 is a diagram showing a portion of a front surface of a battery module according to an embodiment of the present disclosure to demonstrate an expansion pad disposed inside the battery module.

[0041] Figure 12 to Figure 14 is a diagram showing a portion of a cross section of a battery module according to an embodiment of the present disclosure viewed from a side to illustrate an expansion pad provided inside the battery module. DETAILED DESCRIPTION

[0042] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to the general meaning and dictionary meaning, but are interpreted based on the meaning and concept corresponding to the technical aspects of the present disclosure based on the principle of allowing the inventor to appropriately define the terms for the best interpretation. Therefore, the descriptions presented herein are only preferred examples for illustrative purposes and are not intended to limit the scope of the present disclosure, so it should be understood that other equivalent schemes and modifications may be made thereto without departing from the scope of the present disclosure.

[0043] First, refer to Figures 1 to 3 The overall structure of the battery module 1 according to the embodiment of the present disclosure is described.

[0044] refer to Figures 1 to 3 , the battery module 1 according to an embodiment of the present disclosure includes a plurality of battery cells 100 , a bus bar frame 200 , a module case 300 , an air inlet 400 , an air outlet 500 , a sprayer 600 , and a guide plate G.

[0045] The battery cell 100 is arranged in plurality, and the plurality of battery cells 100 are stacked to form a single cell stack. The battery cell 100 may be, for example, a pouch-type battery cell. The battery cell 100 includes a pair of electrode leads 110, which are led out at both sides in a longitudinal direction (a direction parallel to the Y-axis shown in the figure). At the same time, although not shown in the figure, if necessary, the single cell stack may further include a buffer pad disposed between the battery cells 100 adjacent to each other. When the single cell stack is accommodated in the module housing 300, the buffer pad allows the single cell stack to be accommodated in a compressed state, thereby limiting the movement caused by external impact and suppressing the swelling of the battery cell 100.

[0046] The busbar frames 200 are arranged in pairs, and the paired busbar frames 200 cover one side and the other side of the cell stack in the width direction (the direction parallel to the Y axis in the figure). The electrode leads 110 of the battery cells 100 are led out through the slits formed at the busbar frames 200, and are bent and fixed to the busbars provided to the busbar frames 200 by welding or the like. That is, a plurality of battery cells 100 can be electrically connected through the busbars provided to the busbar frames 200.

[0047] The module housing 300 has a substantially rectangular parallelepiped shape and contains the cell stack therein. The module housing 300 includes: a pair of base covers 310, the pair of base covers 310 being respectively configured to cover the lower surface and the upper surface (surfaces parallel to the XY plane) of the cell stack; a pair of side covers 320, the pair of side covers 320 being respectively configured to cover the side surfaces (surfaces parallel to the XZ plane) of the cell stack; a front cover 330, the front cover 330 being configured to cover the front surface (surface parallel to the YZ plane) of the cell stack; and a rear cover 340, the rear cover 340 being configured to cover the rear surface (surface parallel to the YZ plane) of the cell stack.

[0048] The air inlet 400 is formed at one side in the stacking direction of the cell stack (direction parallel to the X-axis), that is, at one side in the longitudinal direction of the battery module 1, and has a hole shape formed through the front cover 330. The air outlet 500 is formed at the other side in the stacking direction of the cell stack, that is, at the other side in the longitudinal direction of the battery module 1, and has a hole shape formed through the rear cover 340. The air inlet 400 and the air outlet 500 are located at diagonally opposite sides along the longitudinal direction of the battery module 1 (direction parallel to the X-axis).

[0049] Meanwhile, a hollow space is formed between the bus bar frame 200 and the side cover 320. That is, a hollow space in which air for cooling the battery cell 100 flows is formed between one of the six outer surfaces of the module case 300 facing one side and the other side in the longitudinal direction (direction parallel to the Y axis) of the battery cell 100 and the bus bar frame 200. The hollow space is formed at each of the two sides in the width direction (direction parallel to the Y axis) of the battery module 1.

[0050] The air inlet 400 is formed at a position corresponding to a hollow space formed at one side in the width direction (direction parallel to the Y-axis) of the battery module 1, and the air outlet 500 is formed at a position corresponding to a hollow space formed at the other side in the width direction of the battery module 1.

[0051] In the battery module 1, the air introduced into the battery module 1 through the air inlet 400 cools the battery cells 100 while moving from a hollow space formed at one side in the width direction of the battery module 1 to a hollow space formed at the other side in the width direction of the battery module 1, and then is discharged through the air outlet 500. That is, the battery module 1 corresponds to an air-cooled battery module.

[0052] Meanwhile, in the present disclosure, unlike the name of the air inlet 400, the air inlet 400 may also be used for cooling, so as to be used as a passage for discharging heated air after the temperature rises. In addition, unlike the name of the air outlet 500, the air outlet 500 may also be used as a passage for introducing external air for cooling. That is, an impeller for forced exhaust may be installed at the air inlet 400 and / or the air outlet 500, and the direction of air circulation may be changed according to the rotation direction of the impeller.

[0053] The sprayer 600 is connected to a supply pipe (not shown) that supplies a cooling fluid such as cooling water, and when the temperature inside the battery module 1 or the gas flow inside the battery module 1 increases beyond a certain level, the sprayer 600 operates to supply the cooling fluid into the battery module 1. In other words, if an abnormal situation occurs in the battery cell 100 to cause exhaust such that high-temperature gas is discharged, the sprayer 600 detects the high-temperature gas and operates. If the sprayer 600 operates in this manner, the cooling fluid can be supplied into the battery module 1 to prevent the battery cell 100 from catching fire and / or exploding due to overheating.

[0054] A portion of the sprayer 600 is exposed outside the rear cover 340, and another portion of the sprayer 600 is disposed to pass through the rear cover 340 and be located in a hollow space formed between the bus bar frame 200 and the side cover 320. The sprayer 600 is installed at a side opposite to the air outlet 500 formed on one side in the longitudinal direction (direction parallel to the Y axis) of the rear cover 340.

[0055] The sprinkler 600 includes a connector 610, a sprinkler head 620, and an insulating cover 630. The connector 610 is located at the outside of the module housing 300 and is connected to a supply pipe (not shown) that supplies a cooling fluid. That is, the connector 610 is made of a metal material and is a component for fastening an external supply pipe. The sprinkler head 620 is located at the inside of the module housing 300 and is connected to the connector 610. The insulating cover 630 covers the sprinkler head 620, thereby preventing the sprinkler head 620 from directly contacting the electrode lead 110 of the battery cell 100 and / or the busbar of the busbar frame 200 and causing a short circuit.

[0056] refer to Figures 3 to 5 The sprinkler head 620 includes a glass bulb 621 and a retaining bracket 622 .

[0057] The glass bulb 621 blocks the cooling fluid injection hole P of the coupler 610, and if the temperature inside the battery module 1 or the flow rate of the internal gas heated by the exhaust gas increases beyond a reference value, the glass bulb 621 ruptures to open the cooling fluid injection hole P. That is, the glass bulb 621 contains a liquid that expands as the temperature rises, and if exhaust occurs in at least some of the battery cells 100 inside the battery module 1 so that the high-temperature exhaust gas fills the battery module 1, the liquid expands. As the liquid expands, the internal pressure of the glass bulb 621 increases, and at the same time, if the external force of the gas acts together due to the high-pressure exhaust gas outside the glass bulb 621, the glass bulb 621 ruptures, so that the cooling fluid fills the inside of the module case 300 through the cooling fluid injection hole P. The retaining bracket 622 is made of a metal material, and surrounds the glass bulb 621 to fix the glass bulb 621 so that it does not move.

[0058] refer to Figure 4 and Figure 6 , the insulating cover 630 includes a fixing portion 631 and a cover portion 632. The fixing portion 631 is attached to the rear cover 340 by clamping. That is, a portion of the fixing portion 631 is located at the outer side of the rear cover 340, and another portion of the fixing portion 631 is located at the inner side of the rear cover 340. The cover portion 632 extends from the fixing portion 631 in a direction substantially perpendicular to the fixing portion 631, and covers the sprinkler head 620.

[0059] The cover portion 632 includes a first region 632a facing the cell stack and the busbar frame 200 and a second region 632b other than the first region. The first region 632a is formed such that the closed area is larger than the open area, and the second region 632b is formed such that the open area is larger than the closed area. The cover portion 632 is at least partially open to allow the cooling fluid sprayed through the cooling fluid spray hole P to be smoothly supplied into the module housing 300.

[0060] In addition, the open area of ​​the first region 632a is smaller than the open area of ​​the second region 632b, so as to minimize the possibility of a short circuit caused by the contact between the holding bracket 622 and the electrode lead 110 and / or the contact between the holding bracket 622 and the bus bar. At the same time, the first region 632a may have at least one cover hole H for spraying a cooling fluid.

[0061] refer to Figure 3 and Figure 7, the guide plate G is installed inside the module housing 300 so that the gas flow inside the module housing 300 can be guided to the sprayer 600. The guide plate G is fixed inside the module housing 300 and is installed obliquely so that one end of the guide plate G in the longitudinal direction (the direction parallel to the X-axis) is oriented toward the sprayer 600. The guide plate G can be installed in plurality. The guide plate G has a shape protruding from the inner surface of the side cover 320 (the direction parallel to the Y-axis) toward the cell stack. The guide plate G can be manufactured separately and attached to the side cover 320, or can be formed integrally with the side cover 320.

[0062] The gas having a strong tendency to move upward according to the temperature increase inside the battery module 1 may be guided to flow toward the sprayer 600 due to the guide plate G.

[0063] refer to Figures 8 to 10 The insulating cover 630 may further include an orifice 633 having a longitudinal direction (parallel to the longitudinal direction of the battery module 1) extending from the cover portion 632 to the battery module 1. Figure 4 The orifice 633 may have a hollow truncated cone shape, the diameter of which gradually decreases as it moves away from the cover portion 632.

[0064] The orifice 633 allows the flow direction to be determined by the guide plate G (see Figure 3 ) to move the high-temperature gas directed by the guide plate 633 more centrally toward the sprinkler head 620. In order to move the high-temperature gas centrally toward the sprinkler head 620, one end of the guide plate G may be installed toward the inlet of the orifice 633, as shown in FIG. Fig.10 shown.

[0065] refer to Fig.11 The battery module 1 may further include an expansion pad E configured to at least partially close the air inlet 400 and the air outlet 500 so that when the cooling fluid is supplied into the battery module 1 , the liquid level of the cooling fluid increases rapidly.

[0066] The expansion pad E is attached to the inner surface of the module housing 300 and has a size smaller than the open area of ​​the air inlet 400 and the air outlet 500. When the battery module 1 is in normal use, the expansion pad E preferably has a size smaller than about 30% of the open area of ​​the air inlet 400 and the air outlet 500 so that air can flow smoothly through the air inlet 400 and the air outlet 500. Meanwhile, although the drawings of the present disclosure only show the case where the expansion pad E is attached at the bottom of the inner surface of the module housing 300, the expansion pad E may also be attached to the top or side of the module housing 300.

[0067] The expansion pad E expands by contacting the cooling fluid introduced into the battery module 1 to close the air inlet 400 and the air outlet 500. The expansion pad E contains a resin that exhibits a very large expansion rate when absorbing moisture, such as a resin that increases in volume by at least about two times or more compared to the initial volume when a sufficient amount of moisture is provided to the resin. As a resin for the expansion pad E, for example, a non-woven fabric in which SAF (super absorbent fiber) and polyester staple fibers are mixed can be mentioned. SAF is prepared by forming fibers using SAP (super absorbent polymer).

[0068] At the same time, when the air inlet 400 and the air outlet 500 are closed due to the expansion of the expansion pad E, this does not necessarily mean that the air inlet 400 and the air outlet 500 are completely closed so that the cooling fluid does not leak, but also includes a situation where the open area of ​​the air inlet 400 and the air outlet 500 is reduced to reduce the amount of leakage.

[0069] By applying the expansion pad E, when a thermal runaway phenomenon occurs in at least some of the battery modules 1 and thus a cooling fluid is introduced into the battery module 1, the air inlet 400 and the air outlet 500 are closed. If the air inlet 400 and the air outlet 500 are closed as described above, the cooling fluid introduced into the battery module 1 does not escape to the outside, but stays inside the battery module 1, thereby quickly resolving the thermal runaway phenomenon occurring in the battery module 1.

[0070] refer to Fig.12 , the expansion pads E may be provided in pairs. In this case, a pair of expansion pads E are respectively attached to the upper and lower portions of the inner surface of the module housing 300. The pair of expansion pads E are attached at corresponding positions and contact each other when expanded to close the air inlet 400 and the air outlet 500.

[0071] refer to Fig.13, the expansion gasket E may be fixed by inserting at least a portion of the expansion gasket E into a receiving groove 300 a formed to a predetermined depth at the inner surface of the module housing 300 .

[0072] refer to Fig.14 When the expansion pad E expands by absorbing moisture, the expansion movement of the expansion pad E can be guided by a pair of mesh plates 400a and 500a, and the pair of mesh plates 400a and 500a are respectively arranged at both sides of the expansion pad E. The mesh plates 400a and 500a are mesh plates, and have a structure that allows air and cooling fluid to pass through the mesh plates 400a and 500a when the expansion pad E is not expanded.

[0073] Meanwhile, an ESS (Energy Storage System) according to an embodiment of the present disclosure includes a plurality of battery modules according to an embodiment of the present disclosure as described above.

[0074] The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are given by way of illustration only, since various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art from this detailed description.

Claims

1. A battery module, comprising: Multiple battery cells; a module case configured to accommodate a cell stack including the plurality of battery cells and including a pair of side covers configured to cover side surfaces of the cell stack; a sprayer, the sprayer being arranged to pass through the module housing at one side in the stacking direction of the cell stack, the sprayer comprising: a coupler located at the outside of the module housing and connected to a supply pipe supplying a cooling fluid, a sprinkler head located at an inner side of the module housing and connected to the coupler; and an insulating cover configured to cover the sprinkler head; and at least one guide plate fixed inside the module housing and installed obliquely relative to a horizontal plane so that one longitudinal end of the at least one guide plate is oriented toward the sprinkler and the guide plate is configured to protrude from an inner surface of the side cover toward the cell stack, The battery module includes a pair of bus bar frames, which are respectively connected to one side and the other side of the cell stack in a width direction. The insulating cover includes a first area facing the cell stack and the busbar frame and a second area other than the first area, and the first area is formed such that a closed area is larger than an open area, and the second area is formed such that an open area is larger than a closed area.

2. The battery module according to claim 1, wherein: The module housing comprises: a pair of base covers, the pair of base covers being configured to cover a lower surface and an upper surface of the cell stack, respectively; a front cover configured to cover a front surface of the cell stack; and A rear cover is configured to cover a rear surface of the cell stack.

3. The battery module according to claim 2, wherein: The sprayer is provided to penetrate one longitudinal side portion of the rear cover and is located in a hollow space formed between the bus bar frame and the side cover.

4. The battery module according to claim 1, wherein: The sprinkler head comprises: a glass bulb disposed to block a cooling fluid injection hole of the coupler and configured to rupture to open the cooling fluid injection hole when a temperature or a flow rate of gas inside the battery module increases beyond a reference value; and A holding bracket is configured to fix the glass bulb while surrounding the glass bulb.

5. The battery module according to claim 1, wherein: The first region has at least one cover hole for injecting the cooling fluid.

6. The battery module according to claim 2, wherein: The battery module comprises: an air inlet formed through the front cover; an air outlet formed through the rear cover; and An expansion pad is disposed at an inner side of the air outlet and the air inlet and is configured to at least partially close the air inlet and the air outlet by expanding when contacting the cooling fluid introduced into the battery module.

7. The battery module according to claim 6, wherein: The expansion pad is attached to an inner surface of the module housing.

8. The battery module according to claim 6, wherein: The expansion pad is at least partially inserted into a receiving groove formed at an inner surface of the module case.

9. The battery module according to claim 6, wherein: The battery module includes mesh plates respectively disposed at both sides of the expansion pad to guide expansion movement of the expansion pad.

10. The battery module according to claim 6, wherein: The air inlet and the air outlet are formed at positions corresponding to a hollow space formed between the bus bar frame and the side cover.

11. An energy storage system comprising a plurality of battery modules according to any one of claims 1 to 10.

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