Electricity storage device

Abstract

The utility model provides an electricity storage device which comprises an upper shell, a lower shell, a breathable film, a plurality of battery cells and a tab support, the upper shell and the lower shell are connected in a sealed mode, a first containing cavity is formed in the upper shell, a second containing cavity is formed in the lower shell, and the battery cells are installed in the second containing cavity. An opening communicated with the second accommodating cavity is formed in one side, close to the upper shell, of the lower shell, the tab bracket is mounted at the opening, and tabs of the plurality of battery cells are fixed on the tab bracket; the outer surface of the lower shell is further provided with an exhaust hole communicated with the second containing cavity, and the breathable film covers the exhaust hole. According to the electricity storage device provided by the invention, the exhaust hole communicated with the second accommodating cavity is formed in the outer surface of the lower shell, and the breathable film covers the exhaust hole, so that even if water vapor enters the electricity storage device through the breathable film, the water vapor also enters the position of the battery cell in the second accommodating cavity and does not enter the position of the BMS plate; in this way, the BMS board can be prevented from being damaged by moisture, and the purpose of protecting the BMS board is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy, in particular to a power storage device. BACKGROUND

[0002] With the rapid development of battery technology, more and more fields need to use power storage devices. In order to prevent the power storage device from exploding, a breathable film is usually arranged on the top of the power storage device. In the height direction of the power storage device, an electric core, a BMS plate and the breathable film are arranged in sequence from bottom to top. The breathable film is usually a breathable film. This may cause water vapor to enter the battery through the breathable film. The water vapor may first contact the BMS plate, which may damage the BMS plate and affect the normal function of the battery.

[0003] In addition, when the electric core in the power storage device mentioned above experiences thermal runaway, the gas will pass through the BMS plate and then pass through the breathable film to be discharged to the outside of the power storage device. The gas impact on the BMS plate may damage the BMS plate. CONTENT OF THE UTILITY MODEL

[0004] Therefore, the present application provides a power storage device to solve the problems of water vapor damaging the BMS plate and thermal runaway damaging the BMS plate.

[0005] In order to achieve the above purpose, the present application provides the following technical solutions:

[0006] A power storage device includes a sealed upper shell and a lower shell, a breathable film, a plurality of electric cores and a tab support, wherein:

[0007] A first accommodating cavity is formed in the upper shell, a second accommodating cavity is formed in the lower shell, a plurality of electric cores are installed in the second accommodating cavity, an opening communicating with the second accommodating cavity is arranged on one side of the lower shell close to the upper shell, the tab support is installed at the opening, and the tabs of the plurality of electric cores are fixed on the tab support.

[0008] An exhaust hole communicating with the second accommodating cavity is further arranged on the outer surface of the lower shell, and the breathable film covers the exhaust hole.

[0009] Optionally, the electric core is a soft package electric core, a structural adhesive is arranged in the second accommodating cavity, and the structural adhesive is filled between the electric core and the inner side wall of the lower shell.

[0010] In the height direction of the lower shell, the height of the structural adhesive is lower than the height of the exhaust hole; and / or

[0011] In the height direction of the electric core, the height of the structural adhesive is lower than the top angle of the side sealing edge of the electric core, and the top of the exhaust hole is higher than the top of the top sealing edge of the electric core.

[0012] Optionally, in the direction perpendicular to the plane where the side seal edge of the battery cell is located, the projection of the exhaust hole coincides with the side seal edge of at least one battery cell.

[0013] Optionally, in the direction perpendicular to the plane where the side seal edge of the battery cell is located, the projection of the exhaust hole coincides with the side seal edge of at least one battery cell.

[0014] Optionally, the plurality of battery cells are stacked into a battery cell group, and in the stacking direction of the battery cells, the distance between the midpoint of the exhaust hole and the side edge of the battery cell group is L1, and the length of the battery cell group is L2, wherein the relationship between L1 and L2 satisfies: 0.3≤L1 / L2≤0.7.

[0015] Optionally, the power storage device further comprises a plate arranged in the lower shell, and the plate and the wall surface of the lower shell enclose an exhaust passage, one end of the exhaust passage is communicated with the second accommodating cavity through a gas guide opening arranged on the plate, and the other end is communicated with the exhaust hole.

[0016] Optionally, in the exhaust direction of the gas in the power storage device, the cross-sectional area of the exhaust passage decreases from the gas guide opening to the exhaust hole.

[0017] Optionally, a structural adhesive is arranged in the second accommodating cavity, and the structural adhesive is filled between the battery cell and the inner side wall of the lower shell.

[0018] In the height direction of the battery cell, the height of the structural adhesive is more than 5mm lower than the top of the side seal edge of the battery cell; and / or,

[0019] The height of the structural adhesive is 0.7 to 0.9 times the height of the battery cell.

[0020] Optionally, the power storage device further comprises a gas guide pipe arranged on the shell wall of the lower shell and connected with the exhaust hole, the gas guide opening and the exhaust hole are located on the same side of the lower shell, and in the height direction of the battery cell, the height of the gas guide opening is higher than the height of the exhaust hole.

[0021] Optionally, the tab support is provided with a through hole, the tab of the battery cell extends to the side of the tab support away from the battery cell through the through hole, and the opening rate of the tab support is 2% to 5.5%.

[0022] The power storage device provided in the application sets an exhaust hole communicating with the second accommodating cavity on the outer surface of the lower shell, and the gas permeable film covers the exhaust hole. Even if water vapor enters the power storage device through the gas permeable film, the water vapor will enter the position where the battery cell is located in the second accommodating cavity and will not enter the position where the BMS board is located. In this way, the water vapor can be prevented from damaging the BMS board, so as to achieve the purpose of protecting the BMS board.

[0023] And the tab support divides the cavity in the power storage device into two parts, that is, the tab support separates the first accommodating cavity and the second accommodating cavity. In this way, when the power storage device is in thermal runaway, the gas generated by the battery cell increases the air pressure in the second accommodating cavity, and the gas will be discharged from the gas permeable membrane arranged on the lower shell. In this way, when the power storage device is in thermal runaway, the gas will not be guided from the second accommodating cavity to the first accommodating cavity, so as not to impact the BMS board, thereby protecting the BMS board. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0025] Figure 1 The structural schematic diagram of the power storage device provided in the present embodiment is shown in the figure;

[0026] Figure 2 The structural schematic diagram of the lower shell, the tab support and the BMS board is shown in the figure;

[0027] Figure 3 The structural schematic diagram of the shell and the tab support is shown in the figure;

[0028] Figure 4 The top view of Figure 3 is shown in the figure;

[0029] Figure 5 The cross-sectional view of Figure 4 at A-A is shown in the figure;

[0030] Figure 6 The cross-sectional view of Figure 4 at B-B in one embodiment is shown in the figure;

[0031] Figure 7 The cross-sectional view of Figure 4 at B-B in another embodiment is shown in the figure;

[0032] Figure 8 The structural schematic diagram of the lower shell, the tab support and the gas guide pipe is shown in the figure.

[0033] Figures 1-8 The cross-sectional view of

[0034] 1-upper shell, 2-lower shell, 3-gas permeable membrane, 4-battery cell, 5-tab support, 6-structural adhesive, 7-plate body, 8-gas discharge channel, 9-gas guide pipe, 10-BMS board;

[0035] 201 - vent, 401 - side seal, 402 - tab, 403 - corner of side seal, 404 - top seal, 501 - through hole, 701 - air guide. DETAILED DESCRIPTION

[0036] The application provides a power storage device.

[0037] The technical solutions in the embodiments of the application will be apparently and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0038] As Figures 1-8 shown, the application provides a power storage device, which is used for being installed on an electric device to provide electric energy for the electric device.

[0039] It should be noted that the power storage device provided by the embodiments of the application can be a start-stop battery pack, a low-voltage battery pack, a power battery pack, an energy storage module, etc.; and the electric device can be a car, a two-wheeled vehicle, a power tool, an energy storage power station, etc.

[0040] Please refer to Figures 1 to 4 and Figure 6 and Figure 7 The power storage device mainly comprises a sealed upper shell 1 and a lower shell 2, a breathable film 3, a plurality of battery cells 4 and a tab support 5. The lower shell 2 forms a second accommodating cavity, and the plurality of battery cells 4 are installed in the second accommodating cavity, that is, the lower shell 2 provides a placement space for the plurality of battery cells 4; the battery cell 4 is formed by winding or stacking a positive electrode sheet, a negative electrode sheet and a diaphragm arranged between the positive electrode sheet and the negative electrode sheet, and the connection relationship between the plurality of battery cells 4 is not limited herein. For example, the plurality of battery cells 4 can be connected in series, in parallel or partially connected in series and partially connected in parallel; the upper shell 1 forms a first accommodating cavity, and the upper shell 1 provides a placement space for a BMS board 10; the lower shell 2 is provided with an opening near a side close to the upper shell 1, the opening communicates with the second accommodating cavity, and the tab support 5 is installed near the opening. The tab support 5 divides the space enclosed by the upper shell 1 and the lower shell 2 into two parts, that is, the tab support 5 and the upper shell 1 enclose the first accommodating cavity, the tab support 5 and the lower shell 2 enclose the second accommodating cavity, the tabs 402 of the plurality of battery cells 4 are fixed on the tab support 5, and the tab support 5 provides a mounting and welding position for the tabs 402.

[0041] Specifically, the outer surface of the lower shell 2 is further provided with a vent 201 communicating with the second accommodating cavity, and the breathable film 3 covers the vent 201.

[0042] It should be noted that the air permeable film 3 is a film with low porosity, which only allows a small amount of air to enter and exit the second accommodating cavity. If the power storage device is out of control, it will produce high-temperature gas, causing the pressure in the second accommodating cavity to increase. Since the area where the air permeable film 3 is located is relatively weak, the gas with increased pressure in the second accommodating cavity will be discharged to the outside of the power storage device through the air permeable film 3, thereby achieving pressure relief of the power storage device to avoid explosion of the power storage device.

[0043] In this way, when the power storage device is out of control, the gas pressure in the second accommodating cavity increases, and the gas is discharged from the exhaust hole 201 arranged on the outer surface of the lower shell 2, thereby reducing the impact of high-pressure gas on the components such as the BMS board 10 in the first accommodating cavity, and improving the discharge efficiency of the gas.

[0044] It should be further noted that the BMS board 10 is a circuit board that is a core component of the battery pack, mainly responsible for monitoring, controlling and managing the state of the battery pack to ensure that the battery pack operates in a safe, stable and efficient condition.

[0045] The power storage device with the above structure has the exhaust hole 201 communicating with the second accommodating cavity arranged on the outer surface of the lower shell 2, and the air permeable film 3 covers the exhaust hole 201. In this way, even if water vapor enters the power storage device through the air permeable film 3, the water vapor will enter the position where the battery cell 4 is located in the second accommodating cavity and will not enter the position where the BMS board 10 is located. In this way, the water vapor can be prevented from damaging the BMS board 10, thereby achieving the purpose of protecting the BMS board 10. Moreover, the tab support 5 divides the cavity in the power storage device into two parts, that is, the tab support 5 separates the first accommodating cavity and the second accommodating cavity.

[0046] In this way, when the power storage device is out of control, the battery cell 4 generates gas to increase the gas pressure in the second accommodating cavity, and the gas is discharged from the air permeable film 3 arranged on the lower shell 2. In this way, when the power storage device is out of control, the gas will not be guided from the second accommodating cavity to the first accommodating cavity, and will not impact the BMS board 10, thereby playing a role in protecting the BMS board 10.

[0047] In some embodiments, referring to Figure 4 and Figure 7 , the battery cell 4 is a soft-pack battery cell, and the second accommodating cavity is provided with a structural adhesive 6 filled between the battery cell 4 and the inner side wall of the lower shell 2. The soft-pack battery cell 4 is a battery cell packaged with soft aluminum plastic. The structural adhesive 6 is cured to fix the battery cell 4 located in the lower shell 2. In this way, when the power storage device is assembled, the battery cell 4 located in the lower shell 2 is prevented from shaking, so that the battery cell 4 and the lower shell 2 form a whole, thereby improving the stability of the structure of the power storage device.

[0048] Further, in the height direction of the lower shell, the height of the structural adhesive 6 is lower than the height of the exhaust hole 201, that is, the structural adhesive 6 is poured into the lower shell 2, and the structural adhesive 6 flows downward due to gravity, and after the structural adhesive 6 is cured, the exhaust hole 201 is arranged on the upper side of the structural adhesive 6.

[0049] In this way, by arranging the structural adhesive 6, the space of the second accommodating cavity in the lower shell 2 can be reduced, and the exhaust hole 201 meets the above arrangement, so that when the thermal runaway of the power storage device occurs, the high-pressure gas can be conveniently discharged through the exhaust hole 201, thereby improving the discharge efficiency of the gas.

[0050] For example, the height direction of the lower shell is Figure 7 the direction indicated by the bidirectional arrow Z1.

[0051] In some embodiments, referring to Figure 4 and Figure 7 , in the height direction of the battery cell 4, the height of the structural adhesive 6 is lower than the top corner 403 of the side sealing edge of the battery cell 4, and the top of the exhaust hole 201 is higher than the top of the top sealing edge 404 of the battery cell 4. That is, in the direction perpendicular to the side sealing edge 401 of the battery cell 4, at least part of the exhaust hole 201 overlaps with the top corner 403 of the upper side sealing edge of the structural adhesive 6.

[0052] In this way, when the battery cell 4 occurs thermal runaway, since the top corner 403 of the side sealing edge of the battery cell 4 is more vulnerable than other positions of the battery cell 4, the high-pressure gas is easy to rush out from this position; and the exhaust hole 201 meets the above relationship, so that when the battery cell 4 occurs thermal runaway, the gas is discharged from the top corner 403 of the side sealing edge, and the high-pressure gas can be quickly discharged outside the power storage device through the exhaust hole 201, thereby shortening the moving path of the gas and improving the discharge efficiency and the safety of the power storage device in use.

[0053] For example, the height direction of the battery cell 4 is Figure 7 the direction indicated by the bidirectional arrow Z2, and the direction perpendicular to the side sealing edge 401 is Figure 7 the direction indicated by the bidirectional arrow X. It should be noted that the height direction of the shell can be parallel to the height direction of the shell, and the two directions can also have a small angle, that is, the battery cell 4 can be slightly inclined relative to the shell; for example, ±10°.

[0054] In some embodiments, referring to Figure 4 and Figure 7In the direction perpendicular to the plane where the side edge 401 of the battery cell 4 is located, the projection of the exhaust hole 201 coincides with the projection of the side edge 401 of at least one battery cell 4. In this way, when the battery cell 4 is in thermal runaway, the high-pressure gas is more likely to be discharged from the side edge 401, which is thinner than the large surface of the battery cell 4. The exhaust hole 201 satisfies the above relationship, so that when the battery cell 4 is in thermal runaway, the high-pressure gas can be quickly discharged from the side edge 401 through the exhaust hole 201. In this way, the moving path of the gas can be shortened, the exhaust efficiency can be improved, and the safety of the energy storage device in use can be improved.

[0055] In some embodiments, referring to Figure 4 and Figure 7 In the direction perpendicular to the plane where the side edge 401 of the battery cell 4 is located, the projection of the top edge 404 of at least two adjacent battery cells 4 is located within the projection of the exhaust hole 201.

[0056] Specifically, since the projection of the top edge 404 of the two adjacent battery cells 4 is located within the projection of the exhaust hole 201, it can be deduced that the projection of the gap between the two adjacent battery cells 4 is also located within the projection of the exhaust hole 201 in the direction perpendicular to the plane where the side edge 401 of the battery cell 4 is located. The gap between the two adjacent battery cells 4 forms a gas flow channel. In this way, when the other position of the battery cell 4 in the energy storage device is in thermal runaway, the high-pressure gas can be guided to the exhaust hole 201 through the gas flow channel whose projection coincides with the exhaust hole 201. In this way, the flow rate of the gas can be improved, the gas flow to the exhaust hole 201 can be accelerated, and the efficiency of the gas discharge from the exhaust hole 201 can be improved.

[0057] In some embodiments, referring to Figure 4 and Figure 7 The plurality of battery cells 4 are stacked into a battery cell group. In the stacking direction of the battery cells 4, the distance between the midpoint of the exhaust hole 201 and the side edge of the battery cell group is L1, and the length of the battery cell group is L2, wherein 0.3≤L1 / L2≤0.7. That is, in the direction perpendicular to the side edge 401 of the battery cell 4, the projection of the exhaust hole 201 is located on the battery cell group, and in the stacking direction of the battery cell 4, the exhaust hole 201 is located near the middle region of the battery cell group.

[0058] In this way, when thermal runaway occurs in the power storage device, because the exhaust hole 201 is arranged in the middle region, high-pressure gas generated when thermal runaway occurs in the battery cell 4 in any position of the power storage device can reach the position of the exhaust hole 201 more quickly, so that the gas can be discharged to the outside of the power storage device more quickly, avoiding explosion of the power storage device. Further, when the value of L1 / L2 is 0.5, the exhaust hole 201 is located at the central position in the stacking direction of the battery cell 4, and in this way, the moving distance of high-pressure gas when thermal runaway occurs in the battery cell 4 in the power storage device can be further reduced, thereby further improving the safety of the power storage device in use.

[0059] For example, the ratio between L1 and L2 can be 0.3, 0.35, 0.4, 0.5, 0.6, 0.64, 0.7, etc.

[0060] It should be noted that the stacking direction of the battery cell 4 is Figure 4 the direction indicated by the double-headed arrow Y.

[0061] In some embodiments, referring to Figures 4 to 6 The power storage device further comprises a plate body 7 arranged in the lower shell 2, the plate body 7 and the wall surface of the lower shell 2 form an exhaust passage 8, one end of the exhaust passage 8 is communicated with the second accommodating cavity through a gas guide opening 701 arranged on the plate body 7, and the other end is communicated with the exhaust hole 201.

[0062] In this way, when thermal runaway occurs in the battery cell 4 in the power storage device, high-pressure gas first flows to the gas guide opening 701 arranged on the plate body 7, then flows to the exhaust hole 201 through the exhaust passage 8 formed by the plate body 7 and the lower shell 2, and finally flows out of the gas permeable film 3 arranged on the exhaust hole 201 to the outside of the power storage device, so that the high-pressure gas is discharged through the exhaust passage 8. In this way, in the height direction of the shell, the height of the gas guide opening 701 is higher than the height of the structural adhesive 6, and the exhaust hole 201 can be arranged at any position of the upper shell 1, so that the convenience of arranging the exhaust hole 201 can be improved.

[0063] In addition, the exhaust passage 8 can also be arranged in other ways, for example, an exhaust pipe connected to the second accommodating cavity and the exhaust hole 201 at both ends is arranged, so that the high-pressure gas generated when the battery cell 4 is in thermal runaway can also be discharged in time.

[0064] It should be noted that in the embodiment in which the wall surface of the plate body 7 and the lower shell 2 encloses the exhaust passage 8, the air guide port 701 can satisfy the following characteristics: in the height direction of the shell, the height of the structural adhesive 6 is lower than the height of the air guide port 701, and / or in the height direction of the battery cell 4, the height of the structural adhesive 6 is lower than the top corner 403 of the side sealing edge of the battery cell 4, and the top of the air guide port 701 is higher than the top of the top sealing edge 404 of the battery cell 4, so as to ensure that the high-pressure gas can quickly flow through the air guide port 701 and the exhaust passage 8 when the battery cell 4 is in thermal runaway; in the direction perpendicular to the plane in which the side sealing edge 401 of the battery cell 4 is located, the projection of the air guide port 701 coincides with the side sealing edge 401 of at least one battery cell 4. Since the side sealing edge 401 of the battery cell 4 or the top corner 403 of the side sealing edge is a relatively weak area, when the battery cell 4 is in thermal runaway, gas is easily discharged from this position, so that the high-pressure gas can quickly flow to the air guide port 701 and be discharged to the outside of the power storage device through the exhaust passage 8; in the direction perpendicular to the plane in which the side sealing edge 401 of the battery cell 4 is located, the projections of the top sealing edges 404 of at least two adjacent battery cells 4 are located within the projection of the air guide port 701; the plurality of battery cells 4 are stacked into a battery cell group, and in the stacking direction of the battery cells 4, the distance between the midpoint of the air guide port 701 and the side edge of the battery cell group is L3, and the length of the battery cell group is L4, wherein L3 and L4 satisfy: 0.3≤L3 / L4≤0.7; through the above setting, when the battery cell 4 in the power storage device is in thermal runaway, the high-pressure gas is quickly guided to the air guide port 701, so as to improve the discharge of the gas through the air guide port 701 and the exhaust passage 8, improve the discharge efficiency of the gas, and improve the safety of the power storage device when it is in thermal runaway.

[0065] In some embodiments, referring to Figures 4 to 6 In the discharge direction of the gas in the power storage device, the cross-sectional area of the exhaust passage 8 decreases from the air guide port 701 to the exhaust hole 201. Here, by setting the exhaust passage 8 as a tapered channel, when the battery cell 4 in the power storage device is in thermal runaway, the tapered channel causes the pressure of the gas to become greater and greater during the flow of the gas in the exhaust passage 8, so as to facilitate the gas to break through the gas permeable film 3, and improve the efficiency of the pressure relief of the power storage device.

[0066] In addition, generally, the plate body 7 and the lower shell 2 are integrally injection molded, and since the exhaust passage 8 enclosed by the inner wall of the plate body 7 and the lower shell 2 is set as a tapered channel, this facilitates the demolding of the lower shell 2 and the plate body 7, and improves the molding effect of the plate body 7 and the lower shell 2.

[0067] In some embodiments, referring to Figures 4 to 6The second accommodating cavity is provided with structural glue 6, which is filled between the battery cell 4 and the inner side wall of the lower shell 2. In the height direction of the battery cell 4, the height of the structural glue 6 is more than 5 mm lower than the top of the side sealing edge 401 of the battery cell 4. Here, the height of the structural glue 6 is ensured to be a certain size lower than the top of the side sealing edge 401 of the battery cell 4, so that the relatively weak side sealing edge 401 and the top corner 403 of the side sealing edge of the battery cell 4 are exposed outside the structural glue 6. In this way, when the battery cell 4 is in thermal runaway, the probability of the position being blown open by high-pressure gas increases, which can realize pressure relief of the directional position of the battery cell 4 and improve the efficiency of discharging high-pressure gas from the energy storage device.

[0068] For example, the height of the structural glue 6 can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 12 mm, 15 mm, etc. lower than the top of the side sealing edge 401.

[0069] In some embodiments, the height of the structural glue 6 is 0.7 to 0.9 times the height of the battery cell 4.

[0070] In this way, most of the area of the battery cell 4 is sealed in the structural glue 6, so that when the battery cell 4 is in thermal runaway, high-pressure gas can only be blown out from the remaining 0.1 to 0.3 times the height of the battery cell 4. By setting the gas guide port 701 in this range, the moving path of the high-pressure gas can be reduced, thereby improving the efficiency of discharging gas from the energy storage device and improving the safety of the energy storage device in thermal runaway.

[0071] In some embodiments, referring to Figures 4 to 6 and Figure 8 , the energy storage device further comprises a gas guide pipe 9 arranged on the shell wall of the lower shell 2 and connected with the exhaust hole 201. By arranging the gas guide pipe 9, the gas discharged from the exhaust hole 201 when the energy storage device is in thermal runaway can be directed and discharged, avoiding gas leakage. Moreover, the gas guide port 701 and the exhaust hole 201 are located on the same side of the lower shell 2, which can reduce the length of the exhaust passage 8, so as to better arrange the exhaust passage 8 and reduce or even avoid the bending of the exhaust passage 8, thereby improving the discharge efficiency of the gas when the energy storage device is in thermal runaway.

[0072] In addition, in the height direction of the battery cell 4, the height of the gas guide port 701 is higher than the height of the exhaust hole 201. Due to the arrangement of the structural glue 6 in the second accommodating cavity, the gas guide port 701 is arranged at the top area of the second accommodating cavity for convenient gas discharge. In this way, the gas guide port 701 and the exhaust hole 201 have a height difference. In this way, when the energy storage device is in thermal runaway, the flow speed of the gas is prevented from blowing open the gas guide pipe 9 connected to the exhaust hole. By setting the height of the gas guide port 701 higher than the height of the exhaust hole 201, the flow speed of the gas can be buffered.

[0073] In addition, in the height direction of the battery cell 4, the height of the air guide port 701 can also be lower than the height of the exhaust hole 201. In this way, the height difference between the air guide port 701 and the exhaust hole 201 can be formed to avoid the flow speed of the gas being too large to knock off the air guide pipe 9 connected to the exhaust hole when the thermal runaway occurs in the energy storage device.

[0074] In some embodiments, the tab support 5 is provided with through holes 501, and the tabs 402 of the battery cell 4 extend to the side of the tab support 5 away from the battery cell 4 through the through holes 501. The opening rate of the tab support 5 is 2% to 5.5%. It should be noted that the opening rate refers to the ratio of the sum of the projection areas of all through holes 501 to the area of the projection of the outer contour of the tab support 5 in the projection direction perpendicular to the large face of the tab support 5. That is, the larger the opening rate, the larger the opening area, and the smaller the opening rate, the smaller the opening area. In the present embodiment, the opening rate of the tab support 5 is ensured to be within the above range. The tab support 5 is only provided with through holes 501 through which all the tabs 402 of the battery cell 4 pass. After the tabs 402 pass through the through holes 501 and are lapped on the through holes 501, the tabs 402 can at least partially shield the through holes 501. The tab support 5 is only provided with holes for the tabs 402 to pass through. In this way, the tab support 5 divides the space enclosed by the upper housing 1 and the lower housing 2 into two relatively closed chambers. In this way, when the battery cell 4 in the energy storage device experiences thermal runaway, since the battery cell 4 is located in the chamber enclosed by the lower housing 2 and the tab support 5, only a small amount of high-pressure gas passes through the through holes 501 in the tab support 5 into the chamber enclosed by the upper housing 1 and the tab support 5. A large amount of gas is discharged to the outside of the energy storage device through the exhaust hole 201. In this way, the influence on the components in the upper housing 1 during thermal runaway is reduced, and the components in the upper housing 1 are protected.

[0075] For example, the opening rate of the tab support 5 can be 2%, 2.2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, etc.

[0076] The basic principles of the present application are described above in combination with specific embodiments. However, it should be noted that the advantages, advantages, effects, etc. mentioned in the present application are only examples and not limitations. These advantages, advantages, effects, etc. cannot be considered as necessary for each embodiment of the present application. In addition, the above specific details are only for the purpose of example and understanding, and are not limited to the present application. The above specific details are not necessary for the implementation of the present application.

[0077] The block diagrams of the devices, apparatuses, equipment, systems involved in the present application are only illustrative examples and are not intended to require or imply that the connection, arrangement, configuration must be as shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, systems can be connected, arranged, configured in any manner. Words such as "include", "contain", "have", and the like are open-ended words, mean "including but not limited to", and can be used interchangeably. The words "or" and "and" used herein mean the word "and / or", and can be used interchangeably, unless the context clearly indicates otherwise. The word "such as" used herein means the phrase "such as but not limited to", and can be used interchangeably.

[0078] It should also be noted that in the devices, apparatuses and methods of the present application, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions of the present application.

[0079] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other aspects without departing from the scope of the present application. Thus, the present application is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0080] It should be understood that the adjectives "first", "second", "third", "fourth", "fifth" and "sixth" used in the embodiments of the present application are only used for more clearly describing the technical solutions, and cannot be used to limit the protection scope of the present application.

[0081] The above description has been given for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. An electrical energy storage device, characterized by, The battery includes an upper shell and a lower shell connected by sealing, a gas permeable membrane, a plurality of battery cells, and a tab holder. A first accommodating cavity is formed in the upper shell, a second accommodating cavity is formed in the lower shell, a plurality of battery cells are installed in the second accommodating cavity, an opening of the second accommodating cavity is formed on one side of the lower shell close to the upper shell, and the tab holder is installed at the opening, and the tabs of the plurality of battery cells are fixed on the tab holder. An outer surface of the lower shell is further provided with an exhaust hole communicating with the second accommodating cavity, and the gas permeable membrane covers the exhaust hole.

2. The power storage device according to claim 1, wherein The battery cell is a soft package battery cell, the second accommodating cavity is provided with structural glue, and the structural glue is filled between the battery cell and the inner side wall of the lower shell. In the height direction of the lower shell, the height of the structural glue is lower than the height of the exhaust hole; and / or In the height direction of the battery cell, the height of the structural glue is lower than the top corner of the side sealing edge of the battery cell, and the top of the exhaust hole is higher than the top of the top sealing edge of the battery cell.

3. The power storage device according to claim 1, wherein In the direction perpendicular to the plane where the side sealing edge of the battery cell is located, the projection of the exhaust hole coincides with the side sealing edge of at least one battery cell.

4. The power storage device according to claim 1, wherein In the direction perpendicular to the plane where the side sealing edge of the battery cell is located, the projections of the top sealing edges of at least two adjacent battery cells are located within the projection of the exhaust hole.

5. The power storage device according to claim 1, wherein A plurality of battery cells are stacked into a battery cell group, in the stacking direction of the battery cell, the midpoint of the exhaust hole is a distance L1 from one side edge of the battery cell group, and the length of the battery cell group is L2, wherein 0.3≤L1 / L2≤0.7 is satisfied between L1 and L2.

6. The power storage device according to claim 1, wherein Further comprising a plate body arranged in the lower shell, the plate body and the wall surface of the lower shell enclosing an exhaust passage, one end of the exhaust passage being communicated with the second accommodating cavity through a gas guide opening formed on the plate body, and the other end being communicated with the exhaust hole.

7. The power storage device according to claim 6, wherein In the discharge direction of the gas in the battery, the cross-sectional area of the exhaust passage decreases from the gas guide opening to the exhaust hole.

8. The power storage device according to claim 6, wherein The second accommodating cavity is provided with structural glue, and the structural glue is filled between the battery cell and the inner side wall of the lower shell. In the height direction of the battery cell, the structural glue height is more than 5mm lower than the top of the side sealing edge of the battery cell; and / or The structural glue height is 0.7 to 0.9 times the height of the battery cell.

9. The power storage device according to claim 6, wherein Further comprising a gas guide pipe connected to the exhaust hole and arranged on the shell wall of the lower shell, the gas guide opening and the exhaust hole are located on the same side of the lower shell, and in the height direction of the battery cell, the height of the gas guide opening is higher than the height of the exhaust hole.

10. The power storage device according to claim 1, wherein The tab holder is provided with a through hole, the tabs of the battery cell extend to the side of the tab holder away from the battery cell through the through hole, and the opening rate of the tab holder is 2% to 5.5%.

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