Battery group integrating cooling and fire fighting and energy storage box

Abstract

The utility model relates to a battery pack integrating cooling and fire fighting and an energy storage box. The battery pack comprises a plurality of battery cells, and a fence and a first liquid accumulation cavity are arranged at the tops of the battery cells; a containing gap is formed between every two adjacent battery cells, a heat dissipation flow channel is formed in each containing gap and comprises a flow channel inlet, a flow channel outlet and at least one liquid accumulation flow channel, a refrigerant flows into the liquid accumulation flow channels through the flow channel inlets, and the refrigerant overflowing out of the liquid accumulation flow channels flows out of the flow channel outlets. The refrigerant positioned in the liquid accumulation flow channel directly cools the side surface of the battery cell; the top and the side face of the battery cell can be evenly covered with refrigerants for overflow heat exchange through the fences and the heat dissipation flow channels, overall heat dissipation of the battery cell can be achieved only by storing a small amount of refrigerants at the bottom of the box body, the heat exchange efficiency of immersion liquid is improved, meanwhile, the liquid consumption is greatly reduced, and the manufacturing cost of the whole system is greatly reduced.

Description

Technical Field

[0001] The present application relates to the field of battery energy storage technology, and in particular to a battery assembly and energy storage box with integrated cooling and fire protection. Background Art

[0002] With the rapid development of demand for new energy storage, energy storage safety has become a crucial part of energy storage projects. In particular, thermal management technology is a top priority for energy storage safety control. Currently, energy storage thermal management mostly adopts two methods: air cooling and liquid cooling. As the charge and discharge rates of energy storage products gradually increase, air cooling solutions can no longer meet the heat dissipation needs of battery cells. Immersion liquid cooling has become a key research direction for battery thermal management needs in the energy storage industry. It is also called direct liquid cooling. Immersion liquid cooling refers to directly immersing the battery cells in an insulating, non-toxic, heat-dissipating cold medium, and removing heat through the liquid to achieve a higher level of thermal management. It has the advantages of rapid cooling and good temperature uniformity. In addition to being a temperature control medium, the cold medium can also be used as a fire-fighting fluid for energy storage systems, combining temperature control and fire protection to achieve long-term safe operation of energy storage systems.

[0003] Currently, there are two main types of immersion liquid cooling: tank-level immersion and pack-level immersion. Tank-level immersion requires high sealing design, is prone to leakage, and requires a large amount of liquid, resulting in a very high system cost. Furthermore, later maintenance of battery cell failures requires draining the entire tank and then opening it for repair, which is demanding and complex. Pack-level immersion offers relatively easy maintenance and reduces the difficulty of sealing design, but it is prone to localized hot spots, and the pack needs to withstand pressure, resulting in high manufacturing costs and still requiring a large amount of liquid. Utility Model Content

[0004] To overcome the above-mentioned deficiencies of the prior art, the present application provides a battery pack and energy storage box with integrated cooling and fire protection, which specifically adopts the following technical solutions:

[0005] A battery assembly with integrated cooling and fire protection, wherein the battery assembly includes a plurality of battery cells;

[0006] A baffle is provided on the top of the battery cell, and a first liquid accumulation cavity covering the bursting valve and the tab is formed inside the baffle;

[0007] An accommodating gap is provided between adjacent battery cells, and a heat dissipation channel is provided in the accommodating gap. The heat dissipation channel includes a channel inlet, a channel outlet and at least one liquid accumulation channel. The channel inlet is located at the edge of the top of the battery cell, and the channel outlet is located at the side edge or bottom of the battery cell. The liquid accumulation channel is close to the side surface of the battery cell, and at least one liquid accumulation channel is connected between the channel inlet and the channel outlet. The refrigerant flows into the liquid accumulation channel through the channel inlet, and the refrigerant overflowing from the liquid accumulation channel flows out from the channel outlet, wherein the refrigerant in the liquid accumulation channel directly cools the side surface of the battery cell.

[0008] Optionally, the enclosure surrounds the top edge of the battery cell, and the first liquid accumulation cavity formed by the enclosure covers the entire top surface of the battery cell, and the first liquid accumulation cavity is connected to the flow channel inlet of the heat dissipation channel.

[0009] Optionally, the enclosure is arranged at the top middle position of the battery cell, and the enclosure is arranged around the minimum edge of the bursting valve and the pole ear respectively, and the first liquid accumulation cavity formed by the enclosure only covers the bursting valve and the pole ear.

[0010] Optionally, the enclosure surrounds the top edge of the battery assembly, and the first liquid accumulation cavity formed by the enclosure covers the entire top surface of the battery assembly.

[0011] Optionally, both ends of the battery pack further include end plates, and the heat dissipation channel is located between the end plates and the battery cells.

[0012] Optionally: a first partition is further provided in the accommodating gap, and the heat dissipation channel is located between the first partition and the side surface of the battery cell.

[0013] Optionally: A first partition is provided between adjacent battery cells, and the top edge of the first partition located between adjacent battery cells extends upward to form an extension portion, and the extension portion and the enclosure at the top position of each battery cell together form a first liquid accumulation chamber unit, which covers the top surface of a single battery cell.

[0014] Optionally: the heat dissipation channel adopts a first guide bar and a second guide bar arranged alternately at intervals, wherein the ends of the first guide bars close to the top of the battery cell are connected to each other, and the ends of the second guide bars close to the bottom of the battery cell are connected to each other, and the other ends of the first guide bar and the second guide bar are staggered, and the heat dissipation channel is formed by enclosing the first guide bar and the second guide bar.

[0015] Optionally: the coverage area of ​​the liquid accumulation channel is 50% or more of the side surface area of ​​the battery cell.

[0016] In addition, the present application also discloses an energy storage box with integrated cooling and fire protection, wherein the energy storage box includes the battery pack as described above.

[0017] Beneficial effects

[0018] The technical solution of this application has the following beneficial effects:

[0019] (1) The battery assembly of the present application can evenly cover the top and sides of the battery cell with refrigerant through enclosures and heat dissipation channels to perform overflow heat exchange. As a result, only a small amount of refrigerant is needed during the heat dissipation stage to achieve overall heat dissipation of the battery cell. This not only improves the heat dissipation efficiency of the battery cell, but also greatly reduces the amount of liquid used. While maintaining the ultimate heat dissipation performance of the immersion cooling method, it greatly reduces the cost of the entire system; and by evenly distributing the liquid on the top, local hot spots in the battery cell are avoided, thereby avoiding affecting the normal operation of the system.

[0020] (2) The battery assembly of the present application sets a barrier on the top of the battery cell so that the burst valve or the tab of the battery cell is always immersed in the refrigerant, and the adjacent battery cells are heat-insulated by the liquid accumulation flow channel that continuously stores liquid in the heat dissipation flow channel. When the temperature of the battery cell rises, the refrigerant in the liquid accumulation flow channel partially evaporates and absorbs heat, thereby avoiding excessive temperature increase, which can effectively suppress the heat spread after thermal runaway of the battery cell and ensure safe and reliable operation of the battery cell.

[0021] (3) When the battery cell of the battery assembly of the present application is in thermal runaway, the heat inside the battery cell can be absorbed by the refrigerant stored in the liquid accumulation flow channel, and the liquid absorbs heat and heats up to its boiling point to vaporize, thereby preventing the spread of heat and causing thermal runaway of adjacent battery cells; in addition, after the top pressure relief valve of the battery cell explodes due to thermal runaway, the ejected high-temperature gas is cooled by the liquid in the liquid accumulation cavity of the top enclosure of the battery cell and then enters the battery cell. The cooled gas is difficult to react with oxygen, effectively avoiding secondary combustion runaway; at the same time, after the pressure relief valve on the top of the thermal runaway battery cell is depressurized, the pressure relief valve is immersed in the water seal of the insulating cold fluid in the liquid accumulation cavity in the enclosure, preventing the oxygen in the battery cell from entering the battery cell for chemical reaction, further suppressing the spread of thermal runaway of the battery cell.

[0022] (4) The battery assembly of the present application can effectively control the overall operating weight of the device by significantly reducing the amount of liquid used, thereby reducing deployment and installation requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the installation structure in which the battery group is located inside the energy storage box in an embodiment of the present application.

[0024] Figure 2 This is a structural schematic diagram of a fence in an embodiment of the present application.

[0025] Figure 3 for Figure 2 Schematic diagram of the side cross-section structure of the middle enclosure structure.

[0026] Figure 4 This is a schematic structural diagram of another enclosure in an embodiment of the present application.

[0027] Figure 5 for Figure 4 Schematic diagram of the side cross-section structure of the middle enclosure structure.

[0028] Figure 6 This is a schematic structural diagram of another enclosure in an embodiment of the present application.

[0029] Figure 7 for Figure 6 Schematic diagram of the side cross-section structure of the middle enclosure structure.

[0030] Figure 8 Schematic diagram of the structure of the heat dissipation channel in the embodiment of the present application.

[0031] Figure 9 This is a schematic diagram of a heat dissipation channel structure located on the first partition in an embodiment of the present application.

[0032] Figure 10 This is a schematic diagram of another heat dissipation channel structure located on the first partition in an embodiment of the present application.

[0033] Figure 11 This is a schematic diagram of another heat dissipation channel structure located on the first partition in an embodiment of the present application.

[0034] The specific meanings of the reference numerals in the accompanying drawings are:

[0035] 1-case; 101-case top; 102-case bottom; 2-battery cell; 201-top of battery cell; 202-bottom of battery cell; 203-edge of top of battery cell; 204-burst valve; 205-ear; 3-first partition; 31-heat dissipation channel; 301-channel inlet; 302-liquid accumulation channel; 303-channel outlet; 304-first guide strip; 305-second guide strip; 306-extension; 4-end plate; 5-enclosure; 501-first liquid accumulation chamber; 5011-first liquid accumulation chamber unit; 502-enclosure top; 503-enclosure bottom; 504-circulation gap; 505-enclosure gap; 6-accommodation gap. DETAILED DESCRIPTION

[0036] The present application will be further described below in conjunction with the accompanying drawings. The following examples are only used to more clearly illustrate the technical solutions of the present application and are not intended to limit the scope of protection of the present application. It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application.

[0037] Combine Figure 1As shown, the embodiment of the present application specifically discloses a battery assembly with integrated cooling and fire protection. The battery assembly includes a plurality of battery cells 2 arranged side by side, and the positive and negative tabs 205 of each battery cell are connected in series. The battery assembly is placed inside the box body 1 of the energy storage box and dissipates heat through the refrigerant circulating inside the box body 1. The refrigerant is evenly distributed on the top of the battery assembly from the top 101 of the box body, and flows downward along the sides of the battery cells to the bottom 102 of the box body due to gravitational potential energy. The refrigerant removes the heat from the battery cells during the flow process, and then is discharged from the interior of the box body 1. After cooling, it flows back to the box body 1 again.

[0038] Specific, combined Figure 2-7 As shown, in the present application, a barrier 5 is provided on the top of the battery cell 2, and a first liquid accumulation cavity 501 covering the bursting valve 204 and the tab 205 is formed inside the barrier 5. Preferably, the top edge of the barrier 5 in the present application is higher than the maximum height of the top 201 of the battery cell 2; in the present application, the barrier 5 on the battery cell 2 can be used to accumulate refrigerant in the first liquid accumulation cavity 501 inside the barrier 5. On the one hand, since the first liquid accumulation cavity 501 covers the bursting valve 204 and the tab 205, the refrigerant in the barrier 5 can dissipate heat and cool the position of the bursting valve 204 and the tab 205. On the other hand, the refrigerant can block the bursting valve 204 or the tab 205 to prevent the bursting valve 204 or the tab 205 from contacting the oxygen in the box body 1, which not only improves the life of the tab 205, but also can block the bursting valve 204 when the battery cell 2 is thermally runaway, to prevent the inside of the battery cell 2 from contacting with external oxygen, thereby preventing the thermal runaway from aggravating. It should be noted that, in the present application, a liquid level gauge may be set in the first liquid accumulation chamber 501, and the refrigerant flow at the top of the battery group may be controlled based on the liquid level data of the first liquid accumulation chamber 501. By comparing the actual liquid level of the first liquid accumulation chamber 501 with the preset liquid level threshold, the refrigerant in the first liquid accumulation chamber 501 may be controlled to always remain at a fixed liquid level, so as to keep the burst valve 204 sealed and avoid reducing the heat dissipation effect of the battery cell 2.

[0039] Furthermore, in order to avoid heat transfer between adjacent battery cells 2 and due to the need for self-cooling, the present application provides heat dissipation channels 31 on both sides of the battery cell 2, such as Figure 8As shown, the heat dissipation channel 31 includes a channel inlet 301, a channel outlet 303 and at least one liquid accumulation channel 302, the channel inlet 301 is located at the edge 203 of the top 201 of the battery cell, the channel outlet 303 is located at the side edge or bottom 202 of the battery cell 2, the liquid accumulation channel 302 is close to the side surface of the battery cell 2, and at least one liquid accumulation channel 302 is connected between the channel inlet 301 and the channel outlet 303, the refrigerant flows into the liquid accumulation channel 302 through the channel inlet 301, and the refrigerant overflowing from the liquid accumulation channel 302 flows out from the channel outlet 303, wherein the refrigerant located in the liquid accumulation channel 302 directly cools the side surface of the battery cell 2. It should be understood that since the battery group includes multiple battery cells 2, an accommodation gap 6 is provided between adjacent battery cells 2, and the heat dissipation channel 31 is located in the accommodation gap 6. It should be noted that in the present application, the heat dissipation channel 31 can be directly formed by the accommodation gap 6, or it can be formed jointly by the first partition 3 and the fitting surface of the battery cell 2.

[0040] It should be noted that the refrigerant in the heat dissipation channel 31 of the present application directly dissipates heat on the side surface of the battery cell 2, which greatly improves the heat dissipation efficiency compared to the traditional liquid cooling plate method. In addition, the liquid accumulation channel 302 of the present application can accumulate some refrigerant. When the energy storage box is working normally, the refrigerant circulates from top to bottom inside the energy storage box, which can dissipate heat on the top and sides of the battery cell 2 and isolate heat transfer between adjacent battery cells 2. When the energy storage box stops working (generally, the refrigerant no longer circulates), at this time, since some refrigerant is accumulated in the liquid accumulation channel 302, the refrigerant in the liquid accumulation channel 302 can isolate heat transfer between adjacent battery cells 2. Therefore, the energy storage box in the present application not only achieves heat dissipation and cooling during the normal working stage, but also can isolate the battery cells 2 of the energy storage box after it stops working, thereby ensuring that the thermal runaway of the battery cell 2 spreads to the adjacent battery cells 2, thereby improving the safety of the energy storage box.

[0041] Optionally, as an embodiment of the enclosure 5 structure, combined with Figure 6 and Figure 7As shown, the enclosure 5 in the present application can be arranged at the top edge of the battery array, that is, the enclosure 5 only needs to surround the battery array once, and the first liquid accumulation cavity 501 formed by the enclosure 5 can cover the entire top surface of the battery array, wherein when a first partition 3 is provided in the accommodating gap 6 between adjacent battery cells 2, the top edge of the first partition 3 can be extended upward to form an extension portion 306, and the first liquid accumulation cavity 501 formed by the enclosure 5 can be divided into a plurality of first liquid accumulation cavity units 5011 covering the burst valve 204 and the tab 205 of a single battery cell 2 through the extension portion 306 of the first partition 3, and each of the first liquid accumulation cavity units 5011 is respectively connected to the channel inlet 301 of the heat dissipation channel 31 on both sides of the battery cell 2. The refrigerant flowing down from the top 101 of the battery case will preferentially accumulate in the first liquid accumulation chamber 501. This refrigerant in the first liquid accumulation chamber 501 dissipates heat from the top 201 surfaces of each battery cell in the battery array, isolating the burst valve 204 and the tab 205 from oxygen. As the refrigerant in the first liquid accumulation chamber 501 accumulates, it flows into the heat dissipation channel 31 between adjacent battery cells 2, entering the liquid accumulation channel 302 of the heat dissipation channel 31 through the channel inlet 301, dissipating heat and isolating the side surfaces of the battery cells 2. It should be explained that in this embodiment, a flow gap 504 may be provided between the bottom 503 of the enclosure and the battery cell 2. When the liquid in the first liquid accumulation chamber 501 accumulates to a certain liquid level, part of the refrigerant may flow through the flow gap 504 to the heat dissipation channel 31 located at the end of the battery group. In addition, when the liquid level in the first liquid accumulation chamber 501 exceeds the top 502 of the enclosure, part of the refrigerant will overflow along the top 502 of the enclosure and flow downward along the surface of the enclosure into the heat dissipation channel 31 to achieve heat dissipation and cooling of the end battery cells.

[0042] Optionally, as an embodiment of the enclosure 5 structure, combined with Figure 2 and Figure 3 As shown, the enclosure 5 in this application can be set at the edge 203 of the top 201 of the battery cell. The enclosure 5 surrounds the edge of the top 201 of the battery cell. The first liquid accumulation cavity 501 formed by the enclosure 5 covers the entire top surface of the battery cell 2, and the first liquid accumulation cavity 501 is connected to the flow channel inlet 301 of the heat dissipation flow channel 31. Figure 3 As shown, the top of the enclosure 502 located around the top of the battery cell 201 is higher than the height of the top of the battery cell 201, so that the first liquid accumulation chamber 501 covers the entire top surface of the battery cell 2, and the refrigerant in the top 101 of the box body will preferentially accumulate in the first liquid accumulation chamber 501. At this time, the refrigerant in the first liquid accumulation chamber 501 can dissipate heat to the entire surface of the top of the battery cell 201 and isolate the burst valve 204 or the tab 205 from oxygen. When the refrigerant in the first liquid accumulation chamber 501 accumulates more than the top of the enclosure 502, the overflowing refrigerant will flow into the enclosure gap 505, and enter the liquid accumulation channel 302 of the heat dissipation channel 31 through the channel inlet 301 at the bottom of the enclosure gap 505, thereby achieving heat dissipation and heat insulation on the side surface of the battery cell 2.

[0043] Optionally, as another embodiment of the enclosure 5 structure, Figure 4 and Figure 5 As shown, the enclosure 5 described in this application can also be set at the middle position of the top 201 of the battery cell, and the enclosure 5 is respectively set around the smallest edge of the burst valve 204 or the tab 205, so that the first liquid accumulation cavity 501 formed by the enclosure 5 only covers the burst valve 204 and the tab 205. Since the heat is most concentrated at the tab position when the battery cell is working, the heat dissipation demand at the tab position is the highest. At this time, concentrating the refrigerant at the tab position can improve the heat dissipation effect at this position. Figure 5 As shown, the first liquid accumulation chamber 501 formed by the enclosure 5 only covers the burst valve 204 and the tab 205. As the refrigerant accumulates in the first liquid accumulation chamber 501, the refrigerant in the first liquid accumulation chamber 501 can isolate the burst valve 204 or the tab 205 from contact with oxygen. When the refrigerant in the first liquid accumulation chamber 501 fills the cavity, the refrigerant will overflow from the top of the enclosure 502 and flow to cover other positions on the top 201 of the battery cell except the burst valve 204 or the tab 205. At this time, the overflowing refrigerant dissipates heat from the top 201 of the battery cell. It should be noted that in this application, in order to ensure uniform heat dissipation at all positions on the surface of the top 201 of the battery cell, a plurality of staggered first capillary flow channels and second capillary flow channels can be provided on the top 201 of the battery cell, wherein the first capillary flow channel is parallel to the length direction of the battery cell 2, and the second capillary flow channel is parallel to the width direction of the battery cell 2, and the width of the first capillary flow channel is greater than the width of the second capillary flow channel. Since the width of the first capillary flow channel is greater than that of the second capillary flow channel, the flow rate of the refrigerant in the first capillary flow channel is faster than that in the second capillary flow channel. When the refrigerant overflows and covers the surface of the top 201 of the battery cell, more refrigerant flows in the length direction of the battery cell 2, thereby making the heat dissipation rate of the top 201 of the battery cell in the opposite direction of the length and width consistent, thereby improving the heat dissipation effect.

[0044] It should be explained that in this application, heat dissipation channels 31 are also provided on the side surfaces of the battery cells at both ends of the battery array. An end plate 4 is provided at each end of the battery array, and a receiving gap 6 is provided between the end plate 4 and the battery cell 2. The heat dissipation channels 31 are located within the receiving gap 6. Similarly, a first partition plate 3 may also be provided in the receiving gap 6 between the end plate 4 and the battery cell 2, and the heat dissipation channels 31 are located between the first partition plate 6 and the side surface of the battery cell 2.

[0045] More specifically, the heat dissipation channel in this application can be formed by the first guide bar 304 and the second guide bar 305 provided between adjacent battery cells 2, combined with Figure 8As shown, the first guide bar 304 and the second guide bar 305 of the present application are arranged alternately at intervals, wherein the end of the first guide bar 304 close to the top 201 of the battery cell is connected to each other, and the end of the second guide bar 305 close to the bottom 202 of the battery cell is also connected to each other, and the other ends of the first guide bar 304 and the second guide bar 305 are not flush, and are arranged in a staggered manner. When two battery cells 2 are assembled, the first guide bar 304 and the second guide bar 305 will be close to the side surfaces of the two battery cells 2, and the side surfaces of the battery cells 2, the first guide bar 304 and the second guide bar 305 will enclose a heat dissipation channel 31 located between adjacent battery cells 2. It should be understood that the heat dissipation channel 31 formed by this structure directly uses the side surface of the battery cell 2 as the inner wall, so that the refrigerant flowing through the heat dissipation channel 31 directly dissipates heat and cools the side surface of the battery cell 2, thereby improving the heat dissipation efficiency. Furthermore, as a connection structure of this heat dissipation channel, the first guide bar 304, the second guide bar 305 and the side surface of the battery cell 2 in the present application can be connected in an integrated molding manner, for example, an injection molding structure of the guide bar is opened on the injection mold of the battery cell 2 shell, so that the guide bar is directly formed on the side surface during the injection molding of the battery cell 2 shell, or the first guide bar 304 and the second guide bar 305 are manufactured separately, and during assembly, the first guide bar 304 and the second guide bar 305 are fixed to the side surface of the battery cell 2 by bonding, welding or snapping.

[0046] As another embodiment of the heat dissipation channel, the present application can also set a first partition 3 between adjacent battery cells 2. Generally, the first partition 3 can be made of heat-insulating and insulating materials, and then a first guide bar 304 and a second guide bar 305 are provided on both sides of the first partition 3. Figure 9-11As shown, the first guide bar 304 and the second guide bar 305 of the present application are arranged alternately and at intervals, and the ends of the first guide bar 304 and the second guide bar 305 are not flush and are staggered, wherein the end of the first guide bar 304 close to the top 201 of the battery cell (or the top of the first partition) is connected to each other, and the end of the second guide bar 305 close to the bottom 23 of the battery cell (or the bottom of the first partition) is also connected to each other. When two battery cells 2 are assembled, the first partition 3 is clamped between adjacent battery cells 2. At this time, the first guide bar 304 and the second guide bar 305 will be close to the side surfaces of the battery cell 2 and the first partition 3 respectively, and the heat dissipation channel 31 located between adjacent battery cells 2 is formed by the side surface of the battery cell 2, the side surface of the first partition 3, the first guide bar 304 and the second guide bar 305. It should be noted that the heat dissipation channel 31 formed by this structure directly uses the side surface of one of the battery cells 2 as the inner wall, so that the refrigerant flowing through the heat dissipation channel 31 directly dissipates heat and cools the side surface of the battery cell 2, thereby improving the heat dissipation efficiency. In addition, as a connection structure of this heat dissipation channel, the first guide bar 304 and the second guide bar 305 in the present application can be respectively connected to the side surface of the first partition 3 in an integral molding. For example, an injection molding structure of the guide bar is provided on the injection mold of the first partition 3, so that the guide bars are directly formed on the two side surfaces of the first partition 3 during injection molding. Alternatively, the first guide bar 304 and the second guide bar 305 are manufactured separately, and during assembly, the first guide bar 304 and the second guide bar 305 are fixed to the side surface of the first partition 3 by bonding, welding or snapping.

[0047] It should be noted that the coverage area of ​​the liquid accumulation channel 302 in this application is generally 50% or more of the side surface area of ​​the battery cell 2. The liquid accumulation channel 302 is used to accumulate part of the refrigerant. The refrigerant accumulated in the liquid accumulation channel 302 is mainly used to dissipate heat from the side of the battery cell 2 and prevent heat from spreading to adjacent battery cells 2. On the one hand, the accumulated refrigerant can be used to dissipate heat from the battery cell 2. In order to improve the effect, the larger the coverage area of ​​the liquid accumulation channel 302, the better. On the other hand, when the energy box is not in operation, even if the battery cell 2 has thermal runaway, the heat generated inside the battery cell 2 will preferentially heat the refrigerant in the liquid accumulation channel 302. The liquid absorbs heat and heats up to its boiling point and vaporizes, thereby preventing the heat from spreading and causing thermal runaway of the adjacent battery cells 2.

[0048] As a specific implementation of the heat dissipation channel structure, Figure 9Taking the structure shown as an example, the heat dissipation channel is located between the battery cell and the first partition. The heat dissipation channel 31 in this embodiment is provided with two liquid accumulation channels 302, the channel inlet 301 is located in the middle of the top 201 of the battery cell (corresponding to the top of the first partition), and a channel outlet 303 is provided on both sides of the bottom 202 of the battery cell (corresponding to the bottom of the first partition), each channel outlet 303 is connected to a liquid accumulation channel 302, and the refrigerant enters the two liquid accumulation channels 302 respectively through the channel inlet 301 due to gravitational potential energy. When the refrigerant in the two liquid accumulation channels 302 accumulates and overflows, the overflowed refrigerant flows to the bottom of the box body 1 through the channel outlets 303 on both sides of the battery cell 2. When the refrigerant stops flowing, refrigerant always remains in the two liquid accumulation channels 302, and the refrigerant can isolate the heat transfer between the battery cells 2 to prevent the thermal runaway of the battery cells 2 from spreading.

[0049] As another specific embodiment of the heat dissipation channel structure, Figure 10 Taking the structure shown as an example, the heat dissipation channel in this embodiment is provided with two liquid accumulation channels 302. The channel inlet 301 is located in the middle of the top 201 of the battery cell (corresponding to the top of the first partition), and a channel outlet 303 is provided at the upper position of each side of the battery cell (corresponding to the two sides of the first partition). Each channel outlet 303 is connected to a liquid accumulation channel 302. The refrigerant enters the two liquid accumulation channels 302 through the channel inlet 301. The refrigerant overflowing from the liquid accumulation channel 302 flows out through the channel outlet 303 connected to each liquid accumulation channel 302. When the refrigerant stops flowing, the refrigerant always remains in the two liquid accumulation channels 302. The refrigerant can isolate the heat transfer between the battery cells 2 to prevent the spread of thermal runaway of the battery cells 2.

[0050] As another specific embodiment of the heat dissipation channel structure, Figure 11 Taking the structure shown as an example, the heat dissipation channel in this embodiment is provided with two liquid accumulation channels 302. The channel inlet 301 is located in the middle of the top 201 of the battery cell (corresponding to the top of the first partition), and a channel outlet 303 is provided at the upper position of one side of the battery cell (corresponding to one side of the first partition). The upper openings of the two liquid accumulation channels 302 remain connected, and the refrigerant enters the two liquid accumulation channels 302 in sequence through the channel inlet 301. The refrigerant overflowing from the liquid accumulation channels 302 flows out through the channel outlet 303 along the side of the first partition 3. When the refrigerant stops flowing, refrigerant always remains in the two liquid accumulation channels 302. The refrigerant can isolate the heat transfer between the battery cells 2 to prevent the spread of thermal runaway of the battery cells 2.

[0051] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A battery pack with integrated cooling and fire protection, characterized in that: The battery pack includes a plurality of battery cells; A baffle is provided on the top of the battery cell, and a first liquid accumulation cavity covering the bursting valve and the tab is formed inside the baffle; An accommodating gap is provided between adjacent battery cells, and a heat dissipation channel is provided in the accommodating gap. The heat dissipation channel includes a channel inlet, a channel outlet and at least one liquid accumulation channel. The channel inlet is located at the edge of the top of the battery cell, and the channel outlet is located at the side edge or bottom of the battery cell. The liquid accumulation channel is close to the side surface of the battery cell, and at least one liquid accumulation channel is connected between the channel inlet and the channel outlet. The refrigerant flows into the liquid accumulation channel through the channel inlet, and the refrigerant overflowing from the liquid accumulation channel flows out from the channel outlet, wherein the refrigerant in the liquid accumulation channel directly cools the side surface of the battery cell.

2. The battery pack according to claim 1, characterized in that: The enclosure surrounds the top edge of the battery core, and the first liquid accumulation cavity formed by the enclosure covers the entire top surface of the battery core, and the first liquid accumulation cavity is connected to the flow channel inlet of the heat dissipation flow channel.

3. The battery pack according to claim 1, characterized in that: The enclosure is arranged at the middle position of the top of the battery cell, and the enclosure is arranged around the minimum edge of the bursting valve and the pole ear respectively. The first liquid accumulation cavity formed by the enclosure only covers the bursting valve and the pole ear.

4. The battery assembly according to claim 1, characterized in that: The enclosure surrounds the top edge of the battery assembly, and the first liquid accumulation cavity formed by the enclosure covers the entire top surface of the battery assembly.

5. The battery assembly according to claim 1, characterized in that: Both ends of the battery assembly further include end plates, and the heat dissipation channel is located between the end plates and the battery cells.

6. The battery pack according to any one of claims 1 to 4, characterized in that: A first partition is further provided in the accommodating gap, and the heat dissipation channel is located between the first partition and the side surface of the battery cell.

7. The battery assembly according to claim 4, characterized in that: A first partition is provided between adjacent battery cells, and the top edge of the first partition located between adjacent battery cells extends upward to form an extension portion. The extension portion and the enclosure at the top position of each battery cell together form a first liquid accumulation chamber unit, which covers the top surface of a single battery cell.

8. The battery assembly according to claim 1, characterized in that: The heat dissipation channel adopts a first guide bar and a second guide bar arranged alternately at intervals, wherein the ends of the first guide bars close to the top of the battery cell are connected to each other, and the ends of the second guide bars close to the bottom of the battery cell are connected to each other, and the other ends of the first guide bar and the second guide bar are staggered, and the heat dissipation channel is formed by enclosing the first guide bar and the second guide bar.

9. The battery assembly according to claim 1, characterized in that: The coverage area of ​​the liquid accumulation channel is 50% or more of the side surface area of ​​the battery cell.

10. An energy storage box with integrated cooling and fire protection, characterized in that: The energy storage box includes the battery pack according to any one of claims 1 to 9.

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