Energy storage device

Abstract

The invention belongs to the technical field of batteries, and relates to an energy storage device, which can reduce the temperature difference of each battery cell, and comprises: a shell, the wall of which is provided with an air inlet and an air outlet; the battery cell group comprises a plurality of battery cells arranged in the first direction, an air duct communicated with the air inlet is formed between every two adjacent battery cells, an outlet of each air duct is communicated with the air outlet, and a valve assembly which at least partially shields the outlet in a controllable manner is arranged at the outlet of each air duct; the temperature control driving mechanism drives the valve assembly to increase the opening degree, and when the temperature of the battery cell limiting the air channel is inducted to be reduced, the temperature control driving mechanism drives the valve assembly to reduce the opening degree.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to an energy storage device. Background Art

[0002] In a traditional air-cooled battery pack, multiple battery cells are arranged in multiple columns inside the battery pack housing, and a fan is provided on the battery pack housing. The fan sucks air, forcing outside air to enter the housing to establish a cooling air duct. Each battery cell generates heat during operation. Since the battery cells are densely arranged, the heat dissipation effect of the battery cells farther away from the fan is not good, and the heat dissipation effects of each battery are uneven. The heat of some battery cells dissipates slowly, and the temperature uniformity of the battery pack is poor. Summary of the Invention

[0003] Based on this, it is necessary to provide an energy storage device that can improve the heat dissipation uniformity of battery cells.

[0004] An energy storage device includes: a housing having an air inlet and an air outlet on its wall; a battery cell group including a plurality of battery cells arranged along a first direction, with an air duct communicating with the air inlet formed between adjacent two battery cells, and an outlet of the air duct communicating with the air outlet. At the outlet of each air duct, there is a valve assembly and a temperature control driving mechanism that can at least partially shield the outlet in a controlled manner. When the temperature of the battery cells defining the air duct rises, the temperature control driving mechanism drives the valve assembly to increase the opening degree; when the temperature of the battery cells defining the air duct is sensed to decrease, the temperature control driving mechanism drives the valve assembly to decrease the opening degree.

[0005] In some embodiments, the valve assembly includes a switch plate and a piston rod. One end of the piston rod is connected to the switch plate, and the other end of the piston rod extends into the receiving cavity of the temperature control driving mechanism; the temperature control driving mechanism includes the receiving cavity, a temperature sensing element, and an elastic reset member. The receiving cavity is in contact with the battery cell, the temperature sensing element is arranged in the receiving cavity, and is used to drive the piston rod to move along the first direction when the temperature of the battery cells defining the air duct rises. The elastic reset member is arranged between the other end of the piston rod and the cavity wall of the receiving cavity, and is used to provide a force for resetting the piston rod.

[0006] In some embodiments, the temperature sensing element is a phase change material capable of gasification or a shape memory alloy. When the temperature of the battery cells defining the air duct rises, the volume of the temperature sensing element increases to drive the piston rod to drive the switch plate to move along the first direction and increase the opening degree of the valve assembly.

[0007] In some embodiments, the receiving cavity includes a first cavity and a second cavity; the temperature sensing element is arranged in the first cavity; the elastic reset member is arranged in the second cavity.

[0008] In some embodiments, a partition is provided between two adjacent battery cells, and secondary air ducts communicating with the air inlet are respectively formed between the partition and the two adjacent battery cells. The valve assembly and the temperature control driving mechanism are provided at the outlet of each secondary air duct.

[0009] In some embodiments, the valve assembly further includes a support frame which has an inner cavity; one end of the opening and closing plate in the first direction is movably assembled in the inner cavity; the end of the partition is inserted and fixed in the inner cavity and is located on the moving path of the opening and closing plate.

[0010] In some embodiments, two adjacent valve assemblies share one support frame.

[0011] In some embodiments, two adjacent battery cells are each configured with the valve assembly and the temperature control driving mechanism; the opening and closing plates of the two valve assemblies can move towards each other and their ends are in contact with each other.

[0012] In some embodiments, each air duct includes multiple sections isolated from each other in its height direction, and the valve assembly and the temperature control driving mechanism are provided in each section of the air duct.

[0013] In some embodiments, an exhaust fan is provided at the air outlet.

[0014] In some embodiments, the housing includes a top plate, a bottom plate and side plates. The air inlet and the air outlet are both provided on the side plates. A wind guiding cavity is formed in the housing. In the second direction, the wind guiding cavity and the air inlet are located on both sides of the battery cell group. The second direction and the first direction are perpendicular to each other and both parallel to the bottom plate or the side plates; the air outlet communicates with the wind guiding cavity in the first direction; the valve assembly and the temperature control driving mechanism are located in the wind guiding cavity.

[0015] In some embodiments, at least two groups of the battery cell groups are provided in the second direction, and the wind guiding cavity is formed between two adjacent battery cell groups.

[0016] In some embodiments, in the first direction and away from the air outlet, the width of the air duct gradually increases, and / or the initial opening degree of the valve assembly gradually increases.

[0017] In some embodiments, the explosion-proof valve of the battery cell is provided on the side of the battery cell facing the top plate; a sealing plate is provided in the housing. The sealing plate is assembled to the battery cell group and isolates the explosion-proof valve of the battery cell from the wind guiding cavity and the air duct.

[0018] In some embodiments, the sealing plate includes a main body portion and a comb tooth portion connected to the main body portion. The main body portion shields the wind guiding cavity from above, and the comb tooth portion is inserted and matched with each air duct.

[0019] In some embodiments, the comb teeth of the comb tooth part and the air duct are sealed with sealant.

[0020] In some embodiments, the explosion-proof valve of the battery cell is arranged on the side of the battery cell facing the top plate; the top of the air duct is sealed with sealant.

[0021] In some embodiments, the explosion-proof valve of the battery cell is located in the air guiding cavity.

[0022] In some embodiments, the housing includes a top plate, a bottom plate and side plates. The air inlet is arranged on the side plate, and the air outlet is arranged on the bottom plate; an air guiding cavity is formed in the housing. In the second direction, the air guiding cavity and the air inlet are located on both sides of the battery cell group. The second direction is perpendicular to the first direction; the explosion-proof valve of the battery cell faces the bottom plate and has a gap with the bottom plate.

[0023] In this application, by arranging a temperature control driving mechanism at the outlet of each air duct, the temperature change of the battery cell can be detected in time. When the temperature of the battery cell in the defined air duct decreases, the temperature control driving mechanism drives the valve assembly to increase the opening degree, so that the air volume passing through and flowing out of the air duct increases, thereby enhancing the heat dissipation effect on the battery cell; when the temperature of the battery cell in the defined air duct increases, the temperature control driving mechanism drives the valve assembly to decrease the opening degree, thereby weakening the heat dissipation effect on the battery cell. In this way, the heat dissipation effects on all battery cells can tend to be uniform, improving the heat dissipation uniformity of the battery cells and reducing the temperature difference of the battery cells. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of an energy storage device according to some embodiments of this application.

[0025] Figure 2 It is a schematic structural diagram of the energy storage device of this application with the top plate, bottom plate, front and rear end plates hidden.

[0026] Figure 3 is Figure 1 a side view of the shown battery pack.

[0027] Figure 4 is Figure 3 a cross-sectional view taken along the A-A direction of

[0028] Figure 5 is Figure 4 a partial enlarged view of I in

[0029] Figure 6 is Figure 2 a schematic structural diagram of the energy storage device of

[0030] Figure 7 a schematic structural diagram of the valve assembly of this application.

[0031] Figure 8 This is a schematic structural diagram of the sealing plate of the present application.

[0032] Reference numerals:

[0033] 1. Energy storage device; 10. Housing; 110. Air inlet; 120. Air outlet; 130. Air guide cavity; 101. Top plate; 102. Bottom plate; 103. Side plate; 1031. Front end plate; 1032. Rear end plate; 1033. Left side plate; 1034. Right side plate; 20. Battery cell group; 210. Battery cell; 211. Explosion-proof valve; 220. Air duct; 221. Partition; 222. Secondary air duct; 30. Valve assembly; 310. Opening and closing plate; 320. Piston rod; 321. Shoulder; 330. Support frame; 331. Inner cavity; 40. Temperature control driving mechanism; 410. Accommodating cavity; 411. First cavity; 412. Second cavity; 413. Cover plate; 420. Temperature sensing element; 430. Elastic reset member; 50. Exhaust fan; 60. Sealing plate; 610. Main body portion; 620. Comb tooth portion; 621. Comb tooth. Detailed implementation manners

[0034] In order to make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the detailed implementation manners of the present application with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0035] In the description of the present application, it should be understood that if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application.

[0036] In addition, if the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, if the term "a plurality" appears, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0037] In this application, unless otherwise clearly specified and defined, if terms such as "installed", "connected", "joined", "fixed", etc. appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] In this application, unless otherwise clearly specified and defined, if there is a description such as a first feature being "on" or "under" a second feature, its meaning can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature in terms of horizontal height. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature in terms of horizontal height.

[0039] If any, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in this application are only for the purpose of illustration and do not represent the only implementation.

[0040] This application provides an energy storage device, which can achieve uniform heat dissipation of each internal battery cell, reduce the temperature difference between each battery cell, and then achieve uniform temperature of the battery pack.

[0041] Refer to Figures 1 to 5As shown in the figure, the energy storage device 1 according to some embodiments of the present application includes a housing 10 and a battery cell group 20 disposed within the housing 10. An air inlet 110 and an air outlet 120 are provided on the wall of the housing 10. The battery cell group 20 includes a plurality of battery cells 210 arranged along a first direction X. An air duct 220 communicating with the air inlet 110 is formed between two adjacent battery cells 210. The outlet of the air duct 220 communicates with the air outlet 120. A valve assembly 30 and a temperature control driving mechanism 40 that can at least partially shield the outlet in a controlled manner are provided at the outlet of each air duct 220. When the temperature of the battery cell 210 defining the air duct 220 rises, the temperature control driving mechanism 40 drives the valve assembly 30 to increase the opening degree. When the temperature of the battery cell 210 defining the air duct 220 is sensed to decrease, the temperature control driving mechanism 40 drives the valve assembly 30 to decrease the opening degree.

[0042] The housing 10 forms a receiving cavity for accommodating the battery cell group 20. The housing 10 has two battery cell groups 20 arranged at intervals along a second direction Y. It can be understood that the number of battery cell groups 20 is not limited to two. The battery cell group 20 includes a plurality of battery cells 210 arranged along the first direction X.

[0043] The housing 10 specifically includes a top plate 101, a bottom plate 102, and side plates 103. The bottom plate 102 and the side plates 103 together enclose the receiving cavity, and the top plate 101 is used to close the receiving cavity. The first direction X is specifically set as the length direction of the housing 10 and the energy storage device 1, and the second direction Y is the width direction of the housing 10 and the energy storage device 1. The direction from the top plate 101 to the bottom plate 102 is the height direction Z of the housing 10 and the energy storage device 1.

[0044] In this embodiment, referring to Figure 1 and Figure 2 , the side plate 103 further specifically includes a front end plate 1031 and a rear end plate 1032 spaced apart in the first direction X, and a left side plate 1033 and a right side plate 1034 spaced apart in the second direction Y. A plurality of air inlets 110 are respectively provided on the left side plate 1033 and the right side plate 1034. The air outlet 120 is provided on the front end plate 1031. A suction fan 50 may further be provided at the air outlet 120, so as to be able to perform forced air cooling on the battery cells 210 of the energy storage device 1.

[0045] Referring to Figure 2 , Figure 4 and Figure 5 , in the same battery cell group 20, an air duct 220 is provided between two adjacent battery cells 210 in the first direction X, and the inlet of each air duct 220 communicates with the air inlet 110. Specifically, the air duct 220 is formed between the large surfaces of two adjacent battery cells 210, so as to be able to better dissipate heat from the battery cells 210. The large surface of the battery cell 210 refers to the side surface with the largest area among the side surfaces of the battery cell 210. It can be understood that generally there are two such large surfaces, which are opposite to each other. Figure 4In the upper battery cell group 20, each air duct 220 communicates with a plurality of air inlets 110 on the left side plate 1033 in a one-to-one correspondence. In the lower battery cell group 20, each air duct 220 communicates with a plurality of air inlets 110 on the right side plate 1034 in a one-to-one correspondence. A plurality of valve assemblies 30 and temperature control driving mechanisms 40 correspondingly arranged on each battery cell group 20 are located between the two battery cell groups 20.

[0046] The battery cells 210 that define the air duct 220 refer to two battery cells 210 that participate in enclosing the air duct 220 in the first direction X. In this application, the temperature control driving mechanism 40 refers to a mechanism that can sense the temperature change of the battery cells 210 and has a driving force output according to the temperature change of the battery cells 210, so that the opening degree change of the valve assembly 30 can be controlled according to the temperature change of the battery cells 210.

[0047] Optionally, referring to Figure 5 , for example, the temperature control driving mechanism 40 includes a temperature sensing element 420 whose volume can change according to temperature. When the volume of the temperature sensing element 420 changes, the opening degree of the valve assembly 30 changes. Optionally, the temperature control driving mechanism 40 includes a temperature sensing element 420 that can detect temperature changes and an electric driving mechanism that receives the temperature signal of the temperature sensing element 420, and the electric driving mechanism can drive the opening degree change of the valve assembly 30. The operating temperature ranges of the temperature control driving mechanisms 40 are the same, so that the temperatures of the battery cells 210 tend to be the same.

[0048] The opening degree of the valve assembly 30 can be understood as the degree of the size of the valve assembly 30 covering the outlet of the air duct 220. When the opening degree increases, the valve assembly 30 allows the air volume flowing out of the outlet of the air duct 220 to increase; conversely, when the opening degree decreases, the air volume flowing out of the outlet of the air duct 220 is allowed to decrease.

[0049] The specific structure of the valve assembly 30 is not limited, as long as it can selectively cover the air outlet 120 of the air duct 220 in the second direction Y. Optionally, referring to Figure 6 and Figure 7 , the valve assembly 30 includes an opening and closing plate 310 and a piston rod 320. One end of the piston rod 320 is connected to the opening and closing plate 310, and the piston rod 320 is driven by the temperature control driving mechanism 40 to drive the opening and closing plate 310 to move, so as to selectively cover the air outlet 120 of the air duct 220.

[0050] In this application, by providing a temperature-controlled driving mechanism 40 at the outlet of each air duct 220, the temperature change of the battery cell 210 can be detected in a timely manner. When the temperature of the battery cell 210 in the defined air duct 220 decreases, the temperature-controlled driving mechanism 40 drives the valve assembly 30 to increase the opening degree, so that the air volume passing through and flowing out of the air duct 220 increases, thereby enhancing the heat dissipation effect on the battery cell 210. When the temperature of the battery cell 210 in the defined air duct 220 increases, the temperature-controlled driving mechanism 40 drives the valve assembly 30 to decrease the opening degree, thereby weakening the heat dissipation effect on the battery cell 210. In this way, the heat dissipation effects on all the battery cells 210 can tend to be uniform, improving the heat dissipation uniformity of the battery cells 210.

[0051] Reference Figures 5 to 7 , in some embodiments, the valve assembly 30 includes a switching plate 310 and a piston rod 320. One end of the piston rod 320 is connected to the switching plate 310, and the other end of the piston rod 320 extends into the accommodation cavity 410 of the temperature-controlled driving mechanism 40. The temperature-controlled driving mechanism 40 includes an accommodation cavity 410, a temperature-sensitive element 420, and an elastic reset member 430. The accommodation cavity 410 is in contact with the battery cell 210. The temperature-sensitive element 420 is arranged in the accommodation cavity 410 and is used to drive the piston rod 320 to move in the first direction X when the temperature of the battery cell 210 in the defined air duct 220 increases. The elastic reset member 430 is arranged between the other end of the piston rod 320 and the inner wall of the accommodation cavity 410 and is used to provide a force for resetting the piston rod 320.

[0052] The accommodation cavity 410 is specifically arranged on one side of the battery cell 210, and the outer surface of the accommodation cavity 410 is in contact with the battery cell 210. The temperature-sensitive element 420 is arranged in the accommodation cavity 410 and is in thermal conduction with the inner wall of the accommodation cavity 410, so that the temperature change of the battery cell 210 can be sensed in a timely manner.

[0053] One end of the piston rod 320 is connected to the switching plate 310, and the two can be detachably connected or integrally formed. The other end of the piston rod 320 is located in the accommodation cavity 410. The piston rod 320 and the accommodation cavity 410 are in sliding fit. The switching plate 310 is located on one side of the outlet of the air duct 220 in the second direction. The switching plate 310 can move in the first direction X under the drive of the piston rod 320, so that the degree of shielding of the outlet of the air duct 220 by it changes.

[0054] The elastic reset member 430 is, for example, a spring, which is configured to provide an elastic force so that the piston rod 320 has a tendency to move away from the outlet of the air duct 220 in the first direction X. The two ends of the elastic reset member 430 respectively abut against the piston rod 320 and the inner wall of the accommodation cavity 410.

[0055] In this application, the temperature control driving mechanism 40 has a receiving cavity 410, and the temperature sensing element 420 is arranged in the receiving cavity 410 to be protected. At the same time, an elastic reset member 430 is arranged between the piston rod 320 and the cavity wall of the receiving cavity 410. After the temperature of the battery cell 210 drops, the elastic reset member 430 can quickly reset the piston rod 320 and the opening and closing plate 310, so that the heat dissipation effects on each battery cell 210 can be more consistent.

[0056] In this embodiment, the temperature sensing element 420 is a phase change material that can be vaporized or a shape memory alloy. The volume of the temperature sensing element 420 increases to drive the piston rod 320 to drive the opening and closing plate 310 to move in the first direction and increase the opening degree of the valve assembly 30.

[0057] The phase change material can be, for example, a lauric acid-capric acid mixed fatty acid, a high-density polyethylene (HDPE) composite material, etc., but is not limited thereto, as long as it matches the temperature range during the operation of the battery cell.

[0058] Specifically, the phase change material is specifically sealed in the receiving cavity 410. At this time, the piston rod 320 and the cavity wall of the receiving cavity 410 are also sealed. When the temperature of the battery cell 210 rises, the phase change material can be at least partially vaporized, so that the volume expands, and then the piston rod 320 is pushed to overcome the resistance of the reset elastic member, and the reset elastic member stores energy. The piston rod 320 makes the opening and closing plate 310 move in the first direction X, so that the degree of shielding the outlet of the air duct 220 is reduced. On the contrary, when the temperature of the battery cell 210 drops, the vaporized phase change material returns to its original state, the volume becomes smaller, and the reset elastic member releases the stored energy, so as to push the piston rod 320 to drive the opening and closing plate 310 to reset.

[0059] In other embodiments, the temperature sensing element 420 can also be a shape memory alloy. The shape memory alloy can be connected or abutted against the other end of the piston rod 320. When the temperature of the battery cell 210 rises, the shape memory alloy extends, so as to push the piston rod 320 to overcome the resistance of the reset elastic member. The piston rod 320 makes the opening and closing plate 310 move in the first direction X, so that the degree of shielding the outlet of the air duct 220 is reduced. On the contrary, when the temperature of the battery cell 210 drops, the shape memory alloy contracts, and the reset elastic member releases the stored energy, so as to push the piston rod 320 to drive the opening and closing plate 310 to reset.

[0060] In this embodiment, through the cooperation of the volume change of the temperature sensing element 420 and the elastic reset member 430, the piston rod 320 can drive the opening and closing plate 310 to reciprocate, so as to change the degree of shielding of the outlet of the air duct 220. Only the temperature sensing element 420 and the elastic reset member 430 need to be arranged in the receiving cavity 410. The overall structure of the temperature control driving mechanism 40 is simple and easy to implement.

[0061] Reference Figure 5 and Figure 7, in some embodiments, the accommodation cavity 410 includes a first cavity 411 and a second cavity 412; the temperature sensing element 420 is disposed in the first cavity 411; and the elastic reset member 430 is disposed in the second cavity 412.

[0062] Specifically, in the first direction X, the accommodation cavity 410 is divided into a first cavity 411 and a second cavity 412. The first cavity 411 is specifically used for placing the phase change material and is sealed by the cover plate 413. The second cavity 412 is used for placing the elastic reset member 430. A shoulder 321 located in the second cavity 412 is provided on the piston rod 320, and the other end of the piston rod 320 extends into the first cavity 411. The elastic reset member 430 is specifically a spring. The spring is sleeved on the piston rod 320, and both ends thereof respectively abut against the shoulder 321 and the inner wall of the second cavity 412. There is a large contact area between the spring and both the piston rod 320 and the second cavity 412, making the positioning of the spring reliable.

[0063] In this embodiment, by providing the second cavity 412, on the one hand, it is convenient to arrange the elastic reset member 430, and on the other hand, the shoulder 321 of the piston rod 320 can also be used to limit the piston rod 320, thereby facilitating the limitation of the extreme positions of the opening and closing plate 310.

[0064] Reference Figures 5 to 7 , in some embodiments, a partition 221 is provided between adjacent battery cells 210. Secondary air ducts 222 communicating with the air inlet 110 are respectively formed between the partition 221 and the two adjacent battery cells 210. A valve assembly 30 and a temperature control driving mechanism 40 are provided at the outlet of each secondary air duct 222.

[0065] In the first direction X, the air duct 220 is divided into two secondary air ducts 222 by the partition 221. The two secondary air ducts 222 can respectively communicate with one air inlet 110 or share one air inlet 110. The partition 221 can be fixed to the housing 10, such as fixed to the top plate 101, the side plate 103 or the bottom plate 102, for example.

[0066] In this embodiment, in the first direction X, in the same battery cell group 20, a valve assembly 30 and a temperature control driving mechanism 40 are respectively arranged at one position for each of the head and tail battery cells 210, while two valve assemblies 30 and two temperature control driving mechanisms 40 are respectively arranged at two positions for each of the intermediate battery cells 210. As Figure 5 shown, taking the air duct 220 formed between the large surfaces of adjacent battery cells 210 as an example, two temperature control driving mechanisms 40 are provided on the side surface of the intermediate battery cell 210 in the second direction Y. The two temperature control driving mechanisms 40 are respectively close to the large surface of the battery cell 210 in the first direction X. The valve assemblies 30 driven by the two temperature control driving mechanisms 40 respectively control the two secondary air ducts 222.

[0067] By providing the partition plate 221, both of the two large surfaces of each battery cell 210 can be subjected to the action of relatively independent cooling air ducts, thereby ensuring that the temperatures among different battery cells 210 in the battery pack are close to each other, avoiding the situation of inconsistent discharge depths caused by large temperature differences, and thus improving the service life of the battery cells 210.

[0068] In the present application, when the partition plate 221 is not provided, it is possible that each battery cell 210 in the same battery cell group 20 is respectively provided with a valve assembly 30 and a temperature control driving mechanism 40 at one location.

[0069] In addition, when the partition plate 221 is not provided, it is still possible that, except for the first and last battery cells 210, each of the other battery cells 210 is provided with two valve assemblies 30 and temperature control driving mechanisms 40, and the setting positions are similar to those when the air duct 220 is divided into two sub-air ducts 222 by the partition plate 221. At this time, the two valve assemblies 30 and temperature control driving mechanisms 40 on each battery cell 210 can respectively adjust the air output near the two large surfaces of the battery cell 210.

[0070] When the air duct 220 is divided into two sub-air ducts 222 by the partition plate 221, for the convenience of arranging the valve assembly 30, referring to Figure 5 、 Figure 7 , the valve assembly 30 further includes a support frame 330, and the support frame 330 has an inner cavity 331; one end of the opening and closing plate 310 in the first direction X is movably assembled in the inner cavity 331. The end of the partition plate 221 can be inserted and fixed in the inner cavity 331 and is located on the moving path of the opening and closing plate 310.

[0071] The height direction of the support frame 330 is the same as the height direction of the housing 10. The bottom of the support frame 330 can support and be fixed to the bottom plate 102. An opening (not shown) can be provided on one side of the inner cavity 331 of the support frame 330 facing the temperature control driving mechanism 40, so that the opening and closing plate 310 can enter the support frame 330 through the opening. When the opening and closing plate 310 moves away from the temperature control driving mechanism 40 and the part entering the support frame 330 increases, the shielding of the opening and closing plate 310 from the sub-air duct 222 decreases, and vice versa, the shielding of the opening and closing plate 310 from the sub-air duct 222 increases.

[0072] The end of the partition plate 221 is in plug-in fit with the support frame 330 and extends into the inner cavity 331 of the support frame 330. Moreover, the end of the partition plate 221 is just located on the moving path of the opening and closing plate 310, thereby limiting the opening and closing plate 310 when the opening and closing plate 310 moves away from the temperature control driving mechanism.

[0073] In this embodiment, by providing the support frame 330, the installation of the partition plate 221 is simplified; at the same time, a guiding support is provided for the movement of the opening and closing plate 310 in the first direction, making the movement of the opening and closing plate 310 more stable.

[0074] Of course, in other embodiments, the partition 221 may abut against the outer side surface of the support frame 330 without being inserted into the inner cavity 331; a baffle is provided in the inner cavity 331 to replace the end interface of the partition 221.

[0075] In the first direction X, the support frame 330 at least shields a part of the secondary air duct 222. For example, if the support frame 330 is a square column structure, one side wall thereof shields the outlet part of the secondary air duct 222. In this way, the opening and closing plate 310 is only used for the remaining part of the outlet of the secondary air duct 222, so that the outlet area of the air duct 220 to be adjusted is small, and it is easy to set the movement stroke of the opening and closing plate 310.

[0076] In some embodiments, two adjacent valve assemblies 30 share a support frame 330.

[0077] Specifically, reference may be made to Figure 7 As shown, the inner cavity 331 of the support frame 330 is arranged to be able to accommodate the two opening and closing plates 310 on both sides. At the same time, the end of the partition 221 is inserted into the support frame 330 and divided into two inner cavities 331, so that the partition 221 can be used to limit the movement of the opening and closing plates 310 on both sides at the same time. Such an arrangement reduces the volume of the valve assembly 30 and solves the problem that it is difficult to set the valve assembly 30 in the small space at the boundary of the two secondary air ducts 222.

[0078] In other embodiments, when two adjacent battery cells 210 are each provided with a separate valve assembly 30 and a temperature control driving mechanism 40; the opening and closing plates 310 of the two valve assemblies 30 can move towards each other and their ends are in contact.

[0079] Specifically, the movement trajectories of the two opening and closing plates 310 are on the same straight line, and the two opening and closing plates 310 can approach each other to reduce the distance, or move relatively away from each other to increase the distance. When the distance between the two opening and closing plates 310 decreases, the degree of shielding of the outlet of the air duct 220 by them increases; when the distance between the two opening and closing plates 310 increases, the degree of shielding of the outlet of the air duct 220 by them decreases.

[0080] In this embodiment, the setting of the support frame 330 is omitted, so the structure of the valve assembly 30 is simplified, and at the same time, the purpose of changing the degree of shielding of the outlet of the air duct 220 can be achieved. Moreover, both of the opening and closing plates 310 can move, so that the area of the outlet of the air duct 220 where air can flow out can be adjusted in the first direction X. For example, the area where air can flow out can be the large surface close to the previous battery cell 210, or the large surface close to the next battery cell 210, so as to be adjusted in time according to the temperature change of each battery cell 210, and ensure that the temperatures between different battery cells 210 in the battery pack are close to each other, avoiding large temperature differences.

[0081] In some embodiments, in order to better dissipate heat from the battery cell 210, each air duct 220 includes multiple sections isolated from each other in its height direction, and each section of the air duct 220 is provided with a valve assembly 30 and a temperature control driving mechanism 40.

[0082] Reference can be made to Figure 6 Understand that in the height direction (up and down direction), multiple isolation members can be provided to divide the air duct 220 into multiple small air paths in the height direction. Each small air path is configured with a valve assembly 30 and a temperature control driving mechanism 40.

[0083] In the height direction, when the temperatures of different regions of the battery cell 210 are relatively high, the temperature control driving mechanism 40 of the small air path corresponding to this region timely controls the corresponding valve assembly 30 to increase the opening degree, thereby increasing the air volume at the large surface of the battery cell 210 in this region.

[0084] In this application, by dividing the air duct 220 into multiple small air paths in the height direction, and each small air path is configured with a valve assembly 30 and a temperature control driving mechanism 40, the uniformity of the temperature of the single battery cell 210 in its own height direction can be provided, thereby providing a more refined temperature control solution.

[0085] In some embodiments, reference is made to Figure 1 At the air outlet 120, an exhaust fan 50 is provided. The exhaust fan 50 is used to achieve active forced air cooling for the battery pack. The specific structure of the exhaust fan 50 is not limited, as long as it can draw air out of the housing 10.

[0086] It should be noted that in this application, when the exhaust fan 50 is not provided at the air outlet 120, it does not affect the implementation of the solution of this application, and the temperature control driving mechanism 40 can control the opening degree of the valve assembly 30 according to the temperature change of the battery cell 210.

[0087] In some embodiments, reference is made to Figure 1 、 Figure 2 、 Figure 4 、 Figure 5 、 Figure 6 , the housing 10 includes a top plate 101, a bottom plate 102 and a side plate 103. The air inlet 110 and the air outlet 120 are both provided on the side plate 103. A wind guiding cavity 130 is formed inside the housing 10. In the second direction Y, the wind guiding cavity 130 and the air inlet 110 are located on both sides of the battery cell group 20. The second direction Y and the first direction X are perpendicular to each other and both parallel to the bottom plate 102 or the side plate 103; the air outlet 120 is communicated with the wind guiding cavity 130 in the first direction; the valve assembly 30 and the temperature control driving mechanism 40 are located inside the wind guiding cavity 130.

[0088] In this embodiment, the air duct 220 includes two secondary air ducts 222, and the flow path of the air is as shown in Figure 4 and Figure 5As shown by the arrow: Two secondary air ducts 222 that enter the air duct 220 from the air inlet 110, and after flowing through the two secondary air ducts 222, then flow to the air outlet 120.

[0089] The air guiding cavity 130 can be formed between the battery cell groups 20, or formed between the battery cell groups 20 and the side plate 103 of the housing 10. The air inlet 110, the air duct 220, the air guiding cavity 130, and the air outlet 120 are connected in sequence to form a cooling air path. Among them, air enters the air duct 220 from the air inlet 110 in the width direction of the housing 10, then flows into the air guiding cavity 130, and finally is discharged from the air outlet 120.

[0090] The valve assembly 30 and the temperature control driving mechanism 40 are both located in the air guiding cavity 130, which does not affect the arrangement of the battery cells 210 and does not affect the energy density of the energy storage device 1.

[0091] In this application, in the second direction, at least two groups of battery cell groups 20 are provided, and an air guiding cavity 130 is formed between adjacent two battery cell groups 20.

[0092] Optionally, in this application, two groups of battery cell groups 20 are provided, and they are arranged along the width direction of the housing 10, and the air guiding cavity 130 between them is shared by the two battery cell groups 20. This is beneficial to reducing the size design of the energy storage device 1 in the width direction.

[0093] Optionally, in this application, more than two groups of battery cell groups 20 are provided, and an air guiding cavity 130 is formed between adjacent two battery cell groups 20. In the second direction Y, the air ducts 220 of each battery cell group 20 are connected in series through a plurality of air guiding cavities 130; among them, one of the plurality of air guiding cavities 130 in the middle is connected to the air outlet 120, and the other air guiding cavities 130 are not connected to the air outlet 120. By the above method, the battery cell group 20 in the middle of the multiple groups of battery cell groups 20 can also use the temperature control driving mechanism 40 and the valve assembly 30 to control the temperature of the battery cells 210.

[0094] Taking the example that there are three groups of battery cell groups 20 arranged in the second direction Y, air inlets 110 are respectively provided on the left side plate 1033 and the right side plate 1034 of the housing 10. For the convenience of description, the three groups of battery cell groups 20 far from the air inlet 110 are respectively defined as the first battery cell group, the second battery cell group, and the third battery cell group, and the second battery cell group is in the middle; two air guiding cavities are formed between the three groups of battery cell groups 20, and are respectively defined as the first air guiding cavity and the second air guiding cavity.

[0095] The inlet of the air duct 220 of the first battery cell group is communicated with the air inlet 110 on the left side plate 1033, and the outlet is communicated with the first air guiding cavity. A temperature control driving mechanism 40 and a valve assembly 30 are arranged at the outlet. The inlet of the air duct 220 of the second battery cell group is communicated with the first air guiding cavity, and the outlet is communicated with the second air guiding cavity 130. A temperature control driving mechanism 40 and a valve assembly 30 are arranged at the outlet. The inlet of the air duct 220 of the second battery cell group is communicated with the air inlet 110 on the right side plate 1034, and the outlet is communicated with the second air guiding cavity. A temperature control driving mechanism 40 and a valve assembly 30 are arranged at the outlet. The second air guiding cavity is communicated with the air outlet 120, while the first air guiding cavity is not communicated with the air outlet 120.

[0096] In this way, after the air enters from the air inlet 110 of the left side plate 1033, it sequentially passes through the air duct 220 of the first battery cell group and the air duct 220 of the second battery cell group, and then flows from the second air guiding cavity to the air outlet 120; after the air enters from the air inlet 110 of the right side plate 1034, it passes through the air duct 220 of the third battery cell group, and then flows from the second air guiding cavity to the air outlet 120.

[0097] The solution of this embodiment can realize that when any number of battery cell groups 20 are set, each battery cell group 20 can use the temperature control driving mechanism 40 and the valve assembly 30 to control the temperature of the battery cells 210.

[0098] In this embodiment, the air flow rate passing through each air duct 220 is the same. To ensure that the cooling effects on each battery cell 210 are as consistent as possible, along the first direction X and away from the air outlet 120, the width of the air duct 220 gradually increases, and / or the initial opening degree of the valve assembly 30 gradually increases.

[0099] The initial opening degree can be understood as the degree of shielding the outlet of the air duct 220 by the valve assembly 30 when the battery pack has not started to supply power to the load and generate working temperature rise. For the normal operating temperature range of the battery cell 210 (usually 20°C to 45°C), the initial opening degree can be understood as the opening degree of the battery cell 210 at 20°C.

[0100] Specifically, when the width of the air duct 220 gradually increases or the initial opening degree of the valve assembly 30 gradually increases, the air flow rate passing through each air duct 220 gradually increases. In this way, the cooling air volume for each battery cell 210 gradually increases, so that the cooling air volume of the battery cells 210 far from the air outlet 120 is larger, thereby ensuring that the cooling effects of each battery cell 210 tend to be consistent. This can also reduce the adjustment frequency of the valve assembly 30 far from the air outlet 120.

[0101] Reference Figure 2 and Figure 6, the explosion-proof valve 211 of the battery cell 210 is provided on the side of the battery cell 210 facing the top plate 101; a sealing plate 60 is provided in the housing 10, and the sealing plate 60 is assembled to the battery cell group 20, and isolates the explosion-proof valve 211 of the battery cell 210 from the air guiding cavity 130 and the air duct 220. Figure 2 In the figure, the position of the explosion-proof valve 211 is only indicated on one battery cell 210. The sealing plate 60 is assembled to the battery cell group 20. The sealing plate 60 closes the top of the air duct 220 and closes the top of the air guiding cavity 130.

[0102] With such a design, after the air enters the air guiding cavity 130, it can only flow along the first direction X towards the air outlet 120, which is beneficial to establishing a cooling air duct with better sealing performance, and thus can reduce the requirement for the power of the exhaust fan 50. In addition, the sealing plate 60 can serve as a bearing surface for placing other circuit components, such as the interconnecting components of different battery cell groups 20.

[0103] Reference Figure 8 , in a specific embodiment, the sealing plate 60 includes a main body portion 610 and a comb-tooth portion 620 connected to the main body portion 610. The main body portion 610 shields the air guiding cavity 130 from above, and the comb-tooth portion 620 is inserted and matched with each air duct 220. The comb-tooth portion 620 can rest on the top of the partition plate 221.

[0104] In this embodiment, a comb-tooth portion 620 extends from each of the opposite sides of the main body portion 610 to cooperate with two battery cell groups 20 respectively. The comb-tooth portion 620 includes a plurality of spaced-apart comb teeth 621, and the width of each comb tooth 621 matches the width of the air duct 220 to be inserted. After each comb tooth 621 is inserted into the air duct 220, it can rest on the top of the partition plate 221. It can be understood that the main body portion 610 may be provided with a comb-tooth portion 620 on only one side. In this way, each battery cell group 20 is provided with a sealing plate 60.

[0105] In this embodiment, the sealing portion cooperates with a plurality of air ducts 220 of the battery cell 210 through the comb-tooth portion 620, and the tops of the air ducts 220 can be closed in one assembly.

[0106] Furthermore, to improve the sealing performance, the comb teeth 621 of the comb-tooth portion 620 and the air duct 220 are sealed with sealant. Specifically, sealant can be coated on the side surfaces of the comb teeth 621, and then the comb teeth 621 are inserted into the air duct 220. The side surfaces of the comb teeth 621 and the inner wall of the air duct 220 (the large surface of the battery cell 210) are bonded with sealant to achieve sealing.

[0107] In some other embodiments, the explosion-proof valve 211 of the battery cell 210 is disposed on the side of the battery cell 210 facing the top plate 101; the top of the air duct 220 is sealed with sealant. In this embodiment, only the top of the air duct 220 is sealed, while the top and bottom of the air guiding cavity 130 are respectively shielded only by the top plate 101 and the bottom plate 102. In this way, due to the improved sealing performance of the air duct 220, the air flow rate through the air duct 220 can be well guaranteed when cooling the battery cell 210.

[0108] In some embodiments, the explosion-proof valve 211 of the battery cell 210 is located inside the air guiding cavity 130. Specifically, Figure 2 In [embodiment], the explosion-proof valve 211 of the battery cell 210 faces the top plate 101, and at this time, the battery cell 210 can be understood as being placed vertically. In this embodiment, however, the explosion-proof valve 211 of the battery cell 210 faces the adjacent battery cell group 20, and the explosion-proof valve 211 enters the air guiding cavity 130. At this time, the battery cell 210 can be understood as being placed horizontally.

[0109] The explosion-proof valve 211 is used to lead out the high-pressure air flow inside the battery cell 210 when the battery cell 210 undergoes thermal runaway, so as to achieve pressure relief. In this embodiment, after the explosion-proof valve 211 of the battery cell 210 is located inside the air guiding cavity 130, the air flow in the air guiding cavity 130 will pass through the explosion-proof valve 211 when flowing towards the air outlet 120, and can drain the air when the explosion-proof valve 211 relieves pressure, thereby reducing the harm caused by the thermal runaway of the battery cell.

[0110] In some embodiments, referring to Figure 1 、 Figure 2 , the housing 10 includes a top plate 101, a bottom plate 102 and a side plate 103. The air inlet 110 is disposed on the side plate 103, and the air outlet 120 is disposed on the bottom plate 102; an air guiding cavity 130 is formed inside the housing 10. In the second direction Y, the air guiding cavity 130 and the air inlet 110 are on both sides of the battery cell group 20, and the second direction Y is perpendicular to the first direction X; the explosion-proof valve 211 of the battery cell 210 faces the bottom plate 102 and has a gap therebetween.

[0111] In this embodiment, the battery cell 210 can be understood as being inverted. When the battery cell 210 undergoes thermal runaway, the explosion-proof valve 211 leads out the high-pressure air flow inside the battery cell 210 into the above-mentioned gap. The air flow in the air guiding cavity 130 continuously flows towards the air outlet 120, thereby forming a negative pressure effect to quickly lead out the above-mentioned high-pressure air flow, thus improving safety.

[0112] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0113] The above embodiments only illustrate several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patented application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. An energy storage device, characterized in that: include: A shell, wherein an air inlet and an air outlet are provided on a wall of the shell; A battery cell group includes a plurality of battery cells arranged along a first direction, an air duct connected to the air inlet is formed between two adjacent battery cells, the outlet of the air duct is connected to the air outlet, wherein a valve assembly and a temperature control drive mechanism are provided at the outlet of each air duct, which can controllably at least partially shield the outlet, when the temperature of the battery cells defining the air duct increases, the temperature control drive mechanism drives the valve assembly to increase the opening, and when the temperature of the battery cells defining the air duct decreases, the temperature control drive mechanism drives the valve assembly to decrease the opening.

2. The energy storage device according to claim 1, characterized in that: The valve assembly comprises an opening and closing plate and a piston rod, one end of the piston rod is connected to the opening and closing plate, and the other end of the piston rod extends into the accommodating cavity of the temperature control drive mechanism; The temperature control drive mechanism includes the accommodating chamber, a temperature sensing element and an elastic reset member. The accommodating chamber is in contact with the battery cell. The temperature sensing element is arranged in the accommodating chamber to drive the piston rod to move along the first direction when the temperature of the battery cell defining the air duct increases. The elastic reset member is arranged between the other end of the piston rod and the cavity wall of the accommodating chamber to provide a force to reset the piston rod.

3. The energy storage device according to claim 2, characterized in that: The temperature sensing element is a phase change material or shape memory alloy that can be vaporized, and when the temperature of the battery core that defines the air duct increases, the volume of the temperature sensing element increases to drive the piston rod to drive the opening and closing plate to move along the first direction and increase the opening of the valve assembly.

4. The energy storage device according to claim 2, characterized in that: The accommodating cavity comprises a first cavity and a second cavity; the temperature sensing element is arranged in the first cavity; and the elastic reset member is arranged in the second cavity.

5. The energy storage device according to claim 2, characterized in that: A partition is provided between two adjacent battery cells, and secondary air ducts connected to the air inlet are respectively formed between the partition and the two adjacent battery cells, and the outlet of each secondary air duct is provided with the valve assembly and the temperature control drive mechanism.

6. The energy storage device according to claim 5, characterized in that: The valve assembly also includes a support frame having an inner cavity; one end of the opening and closing plate in the first direction is movably assembled in the inner cavity; the end of the partition is inserted and fixed in the inner cavity and is located on the moving path of the opening and closing plate.

7. The energy storage device according to claim 6, characterized in that: Two adjacent valve components share the supporting frame.

8. The energy storage device according to claim 2, characterized in that: Two adjacent battery cells are each provided with the valve assembly and the temperature control drive mechanism; wherein the opening and closing plates of the two valve assemblies can move toward each other and the ends are in contact with each other.

9. The energy storage device according to claim 1, characterized in that: Each of the air ducts includes a plurality of sections isolated from each other in the height direction, and each section of the air duct is provided with the valve assembly and the temperature control drive mechanism.

10. The energy storage device according to claim 1, characterized in that: An exhaust fan is arranged at the air outlet.

11. The energy storage device according to claim 1, characterized in that: The shell includes a top plate, a bottom plate and side plates, the air inlet and the air outlet are both arranged on the side plates, an air guide cavity is formed in the shell, in the second direction, the air guide cavity and the air inlet are located on both sides of the battery cell group, the second direction and the first direction are perpendicular to each other and are parallel to the bottom plate or the side plates; the air outlet is connected with the air guide cavity in the first direction; the valve assembly and the temperature control drive mechanism are located in the air guide cavity.

12. The energy storage device according to claim 11, characterized in that: In the second direction, at least two groups of the battery cell groups are arranged, and the air guide cavity is formed between two adjacent battery cell groups.

13. The energy storage device according to claim 11, characterized in that: In the first direction and away from the air outlet, the width of the air duct gradually increases, and / or the initial opening of the valve assembly gradually increases.

14. The energy storage device according to claim 11, characterized in that: The explosion-proof valve of the battery cell is arranged on the side of the battery cell facing the top plate; a sealing plate is arranged in the shell, and the sealing plate is assembled on the battery cell group and isolates the explosion-proof valve of the battery cell from the air guide cavity and the air duct.

15. The energy storage device according to claim 14, characterized in that: The sealing plate includes a main body and a comb-tooth portion connected to the main body, the main body shields the air guide cavity from above, and the comb-tooth portion is plug-fitted with each of the air ducts.

16. The energy storage device according to claim 15, characterized in that: The comb teeth of the comb tooth part and the air duct are sealed by sealant.

17. The energy storage device according to claim 12, characterized in that: The explosion-proof valve of the battery core is arranged on the side of the battery core facing the top plate; the top of the air duct is sealed by a sealant.

18. The energy storage device according to claim 11 or 12, characterized in that: The explosion-proof valve of the battery cell is located in the air guide cavity.

19. The energy storage device according to claim 1, characterized in that: The shell includes a top plate, a bottom plate and side plates, the air inlet is arranged on the side plate, and the air outlet is arranged on the bottom plate; an air guide cavity is formed in the shell, and in the second direction, the air guide cavity and the air inlet are located on both sides of the battery cell group, and the second direction is perpendicular to the first direction; the explosion-proof valve of the battery cell faces the bottom plate, and there is a gap between the bottom plate.

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