Battery and battery pack

Abstract

The utility model provides a battery and a battery pack, the battery comprises a shell, the shell comprises a top wall, a bottom wall and a plurality of side walls, the top wall and the bottom wall are oppositely arranged, the side walls are arranged between the top wall and the bottom wall, and at least one pole is arranged on the top wall; the at least one explosion-proof valve is arranged on the side wall; wherein the distance between the center of the anti-explosion valve and the top wall is set to be h, the height of the side wall is set to be H, and h / H meets the condition that h / H is larger than or equal to 1 / 4 and smaller than or equal to 1 / 2.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates to a battery and a battery pack. Background Art

[0002] In related technologies, an explosion-proof valve is provided in a single battery of a power battery pack or an energy storage battery pack. The explosion-proof valve is crucial for the safety performance of the single battery. The top of the battery is usually provided with a positive electrode terminal and a negative electrode terminal, and the explosion-proof valve is usually arranged between the positive electrode terminal and the negative electrode terminal. When the battery pack is used in a new energy vehicle or an energy storage battery cabinet, the height space of the battery cavity available for installing the battery pack in the new energy vehicle or the energy storage battery cabinet is limited. When the explosion-proof valve is arranged on the top of the single battery, an exhaust channel needs to be arranged above the explosion-proof valve, and this exhaust channel will further increase the height design dimension of the battery pack, thereby causing the design dimension of the battery pack to exceed the installation height dimension of the battery accommodating cavity of the new energy vehicle or the energy storage battery cabinet. Content of the Utility Model

[0003] An embodiment of the utility model provides a battery and a battery pack, which can improve the technical problem that the design dimension of the battery pack caused by the explosion-proof valve designed on the top of the battery exceeds the installation height of the battery accommodating cavity of the new energy vehicle or the energy storage battery cabinet.

[0004] In a first aspect, an embodiment of the utility model provides a battery, and the battery includes:

[0005] A housing, the housing includes a top wall and a bottom wall which are oppositely arranged, and a plurality of side walls arranged between the top wall and the bottom wall, and at least one electrode terminal is arranged on the top wall;

[0006] At least one explosion-proof valve, and the explosion-proof valve is arranged on the side wall;

[0007] Wherein, the distance between the center of the explosion-proof valve and the top wall is set as h, the height of the side wall is set as H, and h / H satisfies: 1 / 4≤h / H≤1 / 2.

[0008] In an embodiment, the side wall includes a first side edge and a second side edge which are oppositely arranged, the interval between the first side edge and the second side edge is set as the width w of the side wall, the distance from the center of the explosion-proof valve to the first side edge or the second side edge is d, and d / w satisfies: 1 / 3<d / w<2 / 3.

[0009] In an embodiment, the projected area of the explosion-proof valve on the side wall is m, the surface area of the side wall is M, and m / M satisfies: 0.025≤m / M≤0.2.

[0010] In one embodiment, h / H = 1 / 3, and / or, d / w = 1 / 2, and / or, m / M = 0.08.

[0011] In one embodiment, the explosion-proof valve is separately provided from and connected to the side wall. The explosion-proof valve includes a first main body portion and a first reinforcing portion located on the first main body portion. The first main body portion is provided with a first scoring portion which is configured as a non-closed arc shape, and the first reinforcing portion is configured to extend inside the first scoring portion.

[0012] In one embodiment, the first scoring portion includes a first section, a second section, and a third section. The first section is connected between one end of the second section and one end of the third section, and the other ends of the second section and the third section are oppositely arranged. The first reinforcing portion includes a first part, a second part, and a third part. One ends of the first part, the second part, and the third part are connected to each other. The other end of the first part is close to the midpoint of the virtual connection line between the other ends of the second section and the third section. The other end of the second part is close to the second section, and the other end of the third part is close to the third section.

[0013] In one embodiment, the explosion-proof valve is configured to be integrally formed with the side wall. The explosion-proof valve includes a second main body portion and a second reinforcing portion located on the second main body portion. The second main body portion is provided with a second scoring portion, and the second reinforcing portion is arranged close to the second scoring portion.

[0014] In one embodiment, the second scoring portion includes a fourth section, a fifth section, and a sixth section. One end of the fourth section is connected to the fifth section, and the other end of the fourth section is connected to the sixth section. Both ends of the fifth section and both ends of the sixth section are oppositely arranged to form a first interval and a second interval. The second reinforcing portion includes a fourth part and a fifth part arranged at intervals. The fourth part is arranged within the first interval, and the fifth part is arranged within the second interval.

[0015] In a second aspect, an embodiment of the present invention provides a battery pack, which includes a box body and at least two battery modules arranged in the box body. Each battery module includes the above-mentioned battery, and the battery module includes an upper-layer battery module and a lower-layer battery module arranged along the height direction of the box body.

[0016] In one embodiment, the box body includes a side plate, the side plate is provided with an exhaust passage and a plurality of through holes, and the plurality of through holes are arranged in one-to-one correspondence with the plurality of explosion-proof valves. The through holes are used to communicate the explosion-proof valves with the exhaust passage.

[0017] In one embodiment, the box body further includes an end plate connected to one end of the side plate. The end plate is further provided with at least one exhaust port for discharging the gas inside the exhaust passage; and / or, the exhaust port is arranged on the side plate.

[0018] In one embodiment, the box body includes a battery chamber and an electrical chamber arranged at intervals. The battery chamber is used to accommodate the battery module, the electrical chamber is used to accommodate the battery management system, the exhaust passage is arranged on one side of the battery chamber, and the exhaust passage is arranged inside the chamber wall of the battery chamber.

[0019] Advantages of the embodiments of the present utility model:

[0020] In the embodiments of the present utility model, by arranging the explosion-proof valve on at least one side wall of the housing, the technical problem that the design size of the battery pack caused by the explosion-proof valve designed on the top of the battery exceeds the installation height of the battery accommodation chamber of the new energy vehicle or the energy storage battery cabinet can be improved. Further, by setting the ratio of the distance h between the center of the explosion-proof valve and the top wall to the height H of the first side wall, that is, h / H, to: 0.25 ≤ h / H ≤ 0.5, the opening pressure of the explosion-proof valve is stabilized, the corrosion of the explosion-proof valve by the electrolyte is reduced, and the safety performance of the battery is improved. Description of the drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present utility model. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 It is a schematic three-dimensional structure diagram of the battery pack provided by the embodiment of the present utility model;

[0023] Figure 2a It is the front view of the battery provided by an embodiment of the present utility model;

[0024] Figure 2b It is the three-dimensional view of the battery provided by an embodiment of the present utility model;

[0025] Figure 2c It is the side view of the battery provided by an embodiment of the present utility model;

[0026] Figure 2d It is the schematic diagram of the surface area size of the side wall and the explosion-proof valve provided by an embodiment of the present utility model;

[0027] Figure 3a It is the side view of the battery provided by another embodiment of the present utility model;

[0028] Figure 3b is a perspective view of a battery provided by another embodiment of the present utility model;

[0029] Figure 4 is a schematic structural view of an explosion-proof valve provided by an embodiment of the present utility model;

[0030] Figure 5 is a schematic structural view of an explosion-proof valve provided by another embodiment of the present utility model;

[0031] Figure 6 is a schematic structural view of an exhaust structure inside a box body provided by an embodiment of the present utility model;

[0032] Figure 7 is a schematic structural view of an exhaust port of a box body provided by an embodiment of the present utility model;

[0033] Reference numerals in the drawings:

[0034] 1. Battery pack; 10. Box body; 11. Side plate; 12. End plate; 13. Exhaust passage; 14. Through hole; 15. Exhaust port; 110. Battery chamber; 120. Electrical chamber; 20. Battery; 21. Shell; 211. Top wall; 212. Bottom wall; 213. Side wall; 2131. First side wall; 21311. First side edge; 21312. Second side edge; 2132. Second side wall; 2133. Third side wall; 2134. Fourth side wall; 30. Connecting piece; 31. Pole; 40. Explosion-proof valve; 41. First main body part; 411. First scoring part; 4111. First section; 4112. Second section; 4113. Third section; 42. First strengthening part; 421. First part; 422. Second part; 423. Third part; 43. Second main body part; 431. Second scoring part; 4311. Fourth section; 4312. Fifth section; 4313. Sixth section; 44. Second scoring part; 441. Fourth part; 442. Fifth part; 451. First interval; 452. Second interval; Detailed implementation manners

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present utility model. In addition, it should be understood that the specific implementation manners described herein are only used to illustrate and explain the present utility model, and are not used to limit the present utility model. In the present utility model, unless otherwise stated, the orientation terms such as "upper" and "lower" generally refer to the upper and lower in the actual use or working state of the device, specifically the drawing direction in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0036] Embodiments of the present application provide a battery pack. The battery pack can be a power battery pack, which is used to store electric energy and serves as an energy supply source for electric vehicles and hybrid vehicles. The battery pack can also be an energy storage battery pack, which includes an energy storage container and is used to store electric energy to provide various functions for the power system, such as a smart mobile power grid. As Figure 1 shown, the battery pack 1 includes a box body 10, a plurality of single cells 20, and a BMS (Battery Management System).

[0037] The box body 10 is used to fix and protect a plurality of single cells and other components. The box body can be assembled by several sub-box bodies. The materials suitable for preparing the box body have good earthquake resistance, waterproof and insulation properties. Suitable materials include metal or plastic materials. The box body 10 is provided with a hollow inner cavity, and the inner cavity of the box body 10 can be divided into a battery cavity 110 and an electrical cavity 120. The battery cavity 110 is used to place a plurality of batteries 20, and the electrical cavity 120 is used to place the BMS and other fixed components.

[0038] A plurality of single cells 20 are arranged in a matrix form in the battery cavity 110. The plurality of single cells 20 can be set in series, or the plurality of single cells 20 can be set in parallel, or the plurality of batteries 20 can be set in a mixed connection of series and parallel, so that the battery pack 1 has a capacity and power suitable for use by electrical equipment. The single cell 20 includes a lithium-ion battery, a nickel-metal hydride battery, a lead-acid battery, a lithium iron phosphate battery, or a multi-component composite material battery.

[0039] The battery pack 1 further includes a plurality of connecting pieces 30. Each connecting piece 30 is used to connect the positive and negative electrodes of two adjacent batteries 20, so that a stable series-parallel connection structure is formed between the positive and negative electrodes of the plurality of batteries 20. The materials used to prepare the connecting pieces 30 include copper, aluminum, or a composite material of copper and aluminum.

[0040] As a power battery pack or an energy storage battery pack, the battery pack further includes a BMS (Battery Management System), which is used to monitor, protect, and manage the working state of the battery pack. The BMS can monitor and balance the voltage and temperature of each single cell, and can also control the power and protection functions during the charging and discharging process of the battery pack.

[0041] An embodiment of the present application provides a single cell 20, which includes a housing 21, an electrode assembly, and an electrolyte.

[0042] Taking the square single cell 20 as an example, the housing 21 is configured to be made of a metal material with certain mechanical strength and corrosion resistance. Suitable metal materials include nickel or steel. The housing 21 has a hollow inner cavity, and the electrode assembly is received in the inner cavity of the housing 21. The housing 21 is used to fix and protect the electrode assembly.

[0043] The electrode assembly includes a positive electrode plate, a separator, and a negative electrode plate. The separator is disposed between the positive electrode plate and the negative electrode plate and is used to separate the positive electrode plate and the negative electrode plate. The electrode assembly can wind the positive electrode plate, the separator, and the negative electrode plate to form a wound core assembly, or can stack the positive electrode plate, the separator, and the negative electrode plate to form a stacked sheet assembly.

[0044] The electrolyte is filled inside the battery 20, so that internal battery structures such as the positive electrode plate and the negative electrode plate are fully immersed in the electrolyte. The electrolyte serves as an ion transport carrier between the positive electrode plate and the negative electrode plate, maintaining the continuity of electron transport inside the battery, enabling the battery to charge and discharge normally.

[0045] The housing 21 further includes a top cover assembly, which is connected to the open end at the top of the housing and is used to seal the open end of the housing. Usually, a positive electrode terminal and a negative electrode terminal are provided on the top cover assembly. The positive electrode plate is electrically connected to the positive electrode terminal through a positive electrode tab, and the negative electrode plate is electrically connected to the negative electrode terminal through a negative electrode tab. Or at least one positive electrode terminal is provided on the top cover assembly. The positive electrode plate is electrically connected to the positive electrode terminal through a positive electrode tab, and the negative electrode plate is electrically connected to the housing or the negative electrode terminal at the bottom of the housing through a negative electrode tab. Or at least one negative electrode terminal is provided on the top cover assembly. The negative electrode plate is electrically connected to the negative electrode terminal through a negative electrode tab, and the positive electrode plate is electrically connected to the housing or the positive electrode terminal at the bottom of the housing through a positive electrode tab.

[0046] In the related art, the single cell in a power battery pack or an energy storage battery pack further includes an explosion-proof valve, and the explosion-proof valve is crucial for the safety performance of the single cell. The explosion-proof valve is usually disposed on the top cover assembly and is located between the positive electrode terminal and the negative electrode terminal, or between two positive electrode terminals, or between two negative electrode terminals. When the power battery pack is used in a new energy vehicle, the height space of the accommodation cavity in the new energy vehicle where the battery pack can be installed is limited. When the explosion-proof valve is disposed on the top of the single cell, an exhaust passage needs to be provided above the explosion-proof valve, and this exhaust passage will further increase the height design dimension of the battery pack, thereby causing the design dimension of the battery pack to exceed the installation height dimension of the battery accommodation cavity of the new energy vehicle.

[0047] Furthermore, when there are multiple terminals on the top cover assembly, the multiple terminals can be one of the positive electrode terminals and the negative electrode terminals or both. The size of the cover plate of the top cover assembly is limited, so that the size available for installing the explosion-proof valve on the top cover assembly is limited, further restricting the design dimension of the explosion-proof valve and thus affecting the explosion-proof performance of the explosion-proof valve.

[0048] Furthermore, when the explosion-proof valve is installed at the bottom of the housing, the explosion-proof valve will be soaked by the electrolyte and thus corroded by the electrolyte, affecting its normal use.

[0049] In the embodiment of the present application, the structure of the explosion-proof valve is further optimized, so as to reduce the situation that the design dimension of the battery pack exceeds the installation height dimension of the battery accommodation cavity of the new energy vehicle due to the design of the explosion-proof valve on the single cell.

[0050] Reference Figure 2a 、 Figure 2b and Figure 2c , the housing 21 of the battery 20 includes a top wall 211 and a bottom wall 212 which are oppositely arranged, and a plurality of side walls 213 connected between the top wall 211 and the bottom wall 212. The plurality of side walls 213 include a first side wall 2131 and a second side wall 2132 which are oppositely arranged, and a third side wall 2133 and a fourth side wall 2134 which are oppositely arranged. Taking a blade battery as an example, the surface areas of the first side wall 2131 and the second side wall 2132 are smaller than the surface areas of the third side wall 2133 and the fourth side wall 2134. In one example, the plurality of side walls 213 and the bottom wall 212 are integrally formed into a main housing with an open structure, and the top wall 211 is provided as a top cover assembly and is connected to the open end of the main housing. The top cover assembly generally includes structures such as a cover plate and a lower plastic. The cover plate is welded to the main housing, and the lower plastic is fixed to the cover plate.

[0051] The battery 20 further includes a terminal 31, and the terminal 31 is fixed on the lower plastic. At least two terminals 31 are spaced apart on the top wall 211, and the two terminals 31 can be one of the positive electrode terminals and the negative electrode terminals or both.

[0052] The battery 20 further includes an explosion-proof valve 40, and the explosion-proof valve 40 is disposed on at least one side wall 213. Specifically, the explosion-proof valve 40 is provided as one, and one explosion-proof valve 40 can be disposed on the first side wall 2131 or the second side wall 2132, or the explosion-proof valve 40 is provided as at least two, and at least two explosion-proof valves 40 are respectively disposed on the first side wall 2131 and the second side wall 2132.

[0053] By disposing the explosion-proof valve 40 on at least one side wall 213 of the battery 20, the technical problem that the design size of the battery pack caused by the explosion-proof valve design exceeds the installation height of the battery accommodation cavity of the new energy vehicle or the energy storage battery cabinet can be improved.

[0054] Continue to refer to Figure 2c , taking the explosion-proof valve 40 disposed on the first side wall 2131 as an example, the first side wall 2131 includes a first side edge 21311 and a second side edge 21312 that are oppositely disposed, the top wall 211 is connected to the top ends of the first side edge 21311 and the second side edge 21312, and the bottom wall 212 is connected to the bottom ends of the first side edge 21311 and the second side edge 21312.

[0055] The distance between the center of the explosion-proof valve 40 and the top wall 211 is set as h, and the height of the first side wall 2131 is set as H. In a square battery, the height H of the first side wall 2131 is the distance between the top wall 211 and the bottom wall 212. In a preferred embodiment, the ratio of the distance h between the center of the explosion-proof valve 40 and the top wall 211 to the height H of the first side wall 2131, that is, h / H satisfies: 0.25 ≤ h / H ≤ 0.5. In a specific embodiment, h / H can be 0.25, 0.30, 0.35, 0.40, 0.45, 0.5, and the values between any two of the above or the range between any two of the above values.

[0056] The inventor found through research that when the ratio of the distance h between the center of the explosion-proof valve 40 and the top wall 211 to the height H of the first side wall 2131, that is, h / H < 0.25, the distance between the explosion-proof valve 40 and the top wall 211 is too close. The top wall 211 is usually set as a top cover assembly structure, and the top cover assembly usually includes structures such as a cover plate, a lower plastic, and a pole. The pole is fixed on the lower plastic part, the cover plate is welded to the main housing, and the explosion-proof valve 40 is usually provided with a notch structure. High-energy laser is used in the welding process of the cover plate and the main housing, and the high heat of the laser will affect the stability of the notch of the explosion-proof valve 40, thereby causing the opening pressure of the explosion-proof valve 40 to be unstable, and further affecting the safety performance of the battery 20.

[0057] Further, the inventors also found that when the ratio of the distance h between the center of the explosion-proof valve 40 and the top wall 211 to the height H of the first side wall 2131, i.e., h / H > 0.5, the distance between the explosion-proof valve 40 and the bottom wall 212 is too close. The free electrolyte usually deposits at the bottom of the battery 20, causing the electrolyte to submerge or at least partially submerge the explosion-proof valve 40. On the one hand, it will corrode the explosion-proof valve 40, thereby affecting the normal valve opening of the explosion-proof valve 40. On the other hand, when the explosion-proof valve 40 opens, a pressure relief hole is formed in the explosion-proof valve 40, and the electrolyte will spray out through the pressure relief hole of the explosion-proof valve 40, thus generating a risk of combustion, greatly affecting the safety performance of the battery 20.

[0058] Through experimental tests on the installation position of the explosion-proof valve 40 and the valve opening pressure range of the explosion-proof valve 40, the inventors found that when the ratio of the distance h between the center of the explosion-proof valve 40 and the top wall 211 to the height H of the side wall 213, i.e., h / H satisfies: 0.25 ≤ h / H ≤ 0.5, the valve opening pressure range of the explosion-proof valve 40 is 0.7 MPa to 0.9 MPa. When h / H satisfies: h / H < 0.25, or when h / H satisfies: h / H > 0.5, the valve opening pressure range of the explosion-proof valve 40 is 0.6 MPa to 1.0 MPa. Thus, it can be seen that when h / H satisfies: 0.25 ≤ h / H ≤ 0.5, the stability of the valve opening pressure of the explosion-proof valve 40 is significantly greater than when h / H < 0.25 or h / H > 0.5.

[0059] In a further preferred embodiment, the inventors found through research that when the ratio of the distance h between the center of the explosion-proof valve 40 and the top wall 211 to the height H of the side wall 213, i.e., the ratio of h / H, is set to 1 / 3, the stability of the valve opening pressure of the explosion-proof valve 40, the influence of the high-energy laser used in the welding process between the top wall and the side wall on the indentation of the explosion-proof valve 40, and the influence of the electrolyte on the corrosion of the explosion-proof valve are in an optimized state, which is beneficial to improving the safety performance of the battery 20.

[0060] By arranging the explosion-proof valve 40 on at least one side wall 213 of the housing 21, correspondingly, the exhaust passage of the explosion-proof valve 40 does not need to be designed in the top space of the single battery, thus effectively enabling the design size of the battery pack to exceed the installation height size of the battery accommodation cavity of the new energy vehicle.

[0061] Further, by arranging the explosion-proof valve 40 on at least one side wall 213 of the housing 21 and arranging the pole 31 on the top wall 211, on the one hand, it can improve the problem that the limited size of the top wall 211 cannot design multiple poles and the explosion-proof valve 40 at the same time. On the other hand, separating the design of the explosion-proof valve 40 and the pole 31 enables the gas-electric structure of the battery 20 to be separated, allowing the explosion-proof valve 40 to release the high-pressure gas generated inside the battery in a timely manner, improving the safety performance of the battery.

[0062] Furthermore, the explosion-proof valve 40 is disposed on the side wall 213, which can effectively improve the problem that the explosion-proof valve 40 is corroded by being immersed in the electrolyte, as compared with disposing the explosion-proof valve 40 on the bottom wall 212.

[0063] Continue to refer to Figure 2c , the first side wall 2131 includes a first side edge 21311 and a second side edge 21312 that are oppositely disposed, the distance between the first side edge 21311 and the second side edge 21312 is set as the width w of the first side wall 2131, and the distance from the center of the explosion-proof valve 40 to the first side edge 21311 or the second side edge 21312 is d. In a preferred embodiment, d / w satisfies: 1 / 3 < d / w < 2 / 3. The inventors studied the ratio relationship between the distance d from the center of the explosion-proof valve 40 to the first side edge 21311 or the second side edge 21312 and the width w of the first side wall 2131 where the explosion-proof valve 40 is located and the opening pressure range of the explosion-proof valve 40, and found that when d / w satisfies: d / w ≤ 1 / 3, or d / w ≥ 2 / 3, the opening pressure of the explosion-proof valve 40 is 0.6 MPa to 1.0 MPa, while when d / w satisfies: 1 / 3 < d / w < 2 / 3, the opening pressure of the explosion-proof valve 40 is 0.7 MPa to 0.9 MPa. Thus, it can be seen that when d / w satisfies: 1 / 3 < d / w < 2 / 3, the stability of the opening pressure of the explosion-proof valve 40 is significantly greater than the stability of the opening pressure of the explosion-proof valve 40 when d / w ≤ 1 / 3 or d / w ≥ 2 / 3.

[0064] In a further preferred embodiment, the axis where the center of the explosion-proof valve 40 is located coincides with the central axis where the first side wall 2131 is located, that is, the distance from the center of the explosion-proof valve 40 to the first side edge 21311 is the same as the distance from the center of the explosion-proof valve 40 to the second side edge 21312, that is, d / w = 1 / 2. When d / w = 1 / 2, since the explosion-proof valve 40 is located on the central axis of the first side wall 2131 and the distance from the center of the explosion-proof valve 40 to the first side edge 21311 is the same as the distance from the center of the explosion-proof valve 40 to the second side edge 21312, under the action of the internal air pressure of the battery, the deformation amounts generated at each part of the explosion-proof valve 40 are relatively balanced, which is beneficial to maintaining the consistency and stability of the opening pressure of the explosion-proof valve 40.

[0065] Refer to Figure 2d, the projected area of the explosion-proof valve 40 on the first side wall 2131 is m, and the surface area of the first side wall 2131 is M. In a preferred embodiment, the ratio between the projected area m of the explosion-proof valve 40 on the first side wall 2131 and the surface area M of the first side wall 2131 is m / M, and m / M is preferably set to: 0.025 ≤ m / M ≤ 0.2. Among them, the ratio between m / M can be 0.03, 0.05, 0.06, 0.08, 0.09, 0.10, 0.11, 0.13, 0.15, 0.16, 0.18, 0.2, as well as the values between any two of the above or the range between any two of the above values.

[0066] The inventor found through research that when the ratio m / M between the projected area m of the explosion-proof valve 40 on the first side wall 2131 and the surface area M of the first side wall 2131 is set to be less than 0.025, the pressure relief area corresponding to the explosion-proof valve 40 is too small, and the exhaust speed of the explosion-proof valve 40 after opening the valve is slow, which will further lead to the risk of the housing 21 bursting. When the ratio m / M between the projected area m of the explosion-proof valve 40 on the first side wall 2131 and the surface area M of the first side wall 2131 is set to be greater than 0.2, a relatively large opening area needs to be reserved on the first side wall 2131 where the explosion-proof valve 40 is located for the design of the explosion-proof valve, which will further result in insufficient strength of the first side wall 2131 itself. Especially in the blade battery, when the explosion-proof valve 40 is arranged on the first side wall 2131 with a small surface area, since the surface area of the first side wall 2131 itself is small, it is crucial to balance the structural strength of the first side wall 2131 itself and the exhaust speed of the explosion-proof valve 40.

[0067] In a further preferred embodiment, the ratio between the projected area m of the explosion-proof valve 40 on the first side wall 2131 and the surface area M of the first side wall 2131 is set to 0.08. When m / M is set to 0.08, the battery 20 has an outstanding effect in balancing the opening speed of the explosion-proof valve 40 and maintaining the strength of the housing 21, which is beneficial to improving the overall performance of the battery 20.

[0068] Continue to refer to Figure 3a and Figure 3b , when multiple pole posts 31 are provided on the top wall 211, if the explosion-proof valve 40 is further arranged on the top wall 211, and there is not enough space reserved on the top wall 211 for the design of the explosion-proof valve 40, which will further result in too small a projected area of the explosion-proof valve 40 designed on the top wall 211, so that the explosion-proof valve 40 designed on the top wall 211 will lead to a slow exhaust speed after opening the valve, further resulting in the risk of the housing 21 bursting. Therefore, when multiple pole posts 31 are provided on the top wall 211 of the battery, the explosion-proof valve 40 is preferably arranged on the side wall 213.

[0069] Refer to Figure 2b andFigure 4 In an embodiment provided by the present application, an installation hole for installing the explosion-proof valve 40 is provided on the side wall 213. The explosion-proof valve 40 is separately arranged from the side wall 213. After the explosion-proof valve 40 is separately formed, the explosion-proof valve 40 is then connected to the side wall 213. The explosion-proof valve 40 is preferably welded to the side wall 213. The explosion-proof valve 40 includes a first main body portion 41 and a first strengthening portion 42, and the first strengthening portion 42 is located inside the first main body portion 41. The first main body portion 41 is provided with a first scoring portion 411, and the first scoring portion 411 is configured as a non-closed arc shape, and the first strengthening portion 42 is configured to extend inside the first scoring portion 411.

[0070] When high-pressure air flow is generated inside the battery 20, the explosion-proof valve 40 deforms under the high-pressure force. Since the wall thickness where the first scoring portion 411 is located is relatively thin, when the pressure value received by the first scoring portion 411 exceeds the rated pressure value, the first scoring portion 411 will break to form a pressure relief port, and the high-pressure air flow inside the battery 20 is discharged through the pressure relief port. By configuring the first scoring portion 411 as a non-closed arc shape and arranging the first strengthening portion 42 inside the first scoring portion 411, the first strengthening portion 42 is used to enhance the overall structural strength of the explosion-proof valve 40 and prevent the explosion-proof valve 40 from deforming severely when subjected to external extrusion. Further, the first strengthening portion 42 can also prevent the explosion-proof valve 40 from being separated from the side wall 213 as a whole after the first scoring portion 411 breaks, thereby causing serious electrolyte spillage.

[0071] Continue to refer to Figure 2b and Figure 4 The first scoring portion 411 includes a first section 4111, a second section 4112, and a third section 4113. The first section 4111 is connected between one end of the second section 4112 and one end of the third section 4113. The other end of the second section 4112 and the other end of the third section 4113 are oppositely arranged, and the other end of the second section 4112 and the other end of the third section 4113 are spaced apart.

[0072] The first strengthening portion 42 includes a first part 421, a second part 422, and a third part 423. One end of the first part 421, one end of the second part 422, and one end of the third part 423 are connected to each other. The other end of the first part 421 is close to the midpoint of the virtual connection line between the other end of the second section 4112 and the other end of the third section 4113 of the first scoring portion 411. The other end of the second part 422 of the first strengthening portion 42 is close to the second section 4112 of the first scoring portion 411, and the other end of the third part 423 of the first strengthening portion 42 is close to the third section 4113 of the first scoring portion 411.

[0073] By configuring the first notch portion 411 into three segments, the first reinforcing portion 42 into three parts, and each segment of the first notch portion 411 corresponding to a part of the first reinforcing portion 42, the overall strength of the explosion-proof valve 40 is kept balanced, and the opening thresholds corresponding to various parts of the first notch portion 411 are basically the same, which is beneficial to maintaining the stability of the overall opening pressure of the explosion-proof valve 40.

[0074] In a specific implementation, the overall structure of the explosion-proof valve 40 is elliptical. The first segment 4111 of the first notch portion 411 is configured as a straight line. The second segment 4112 and the third segment 4113 of the first notch portion 411 are configured as arc segments symmetrically arranged with respect to the first segment 4111. The first part 421, the second part 422, and the third part 423 of the first reinforcing portion 42 are all configured as straight lines, and the intersection points of the first part 421, the second part 422, and the third part 423 are basically located at the center of the first notch portion 411.

[0075] The explosion-proof valve 40 is usually formed by stamping an aluminum shell, and the wall thickness of the explosion-proof valve 40 itself is relatively thin. Therefore, when the battery is externally squeezed, the explosion-proof valve 40 connected to the side wall 213 is prone to deformation. In order to improve the deformation problem of the explosion-proof valve 40, in another embodiment provided in the present application, the explosion-proof valve 40 is configured to be integrally formed with the side wall 213. Since there is no weld between the explosion-proof valve 40 and the side wall 213, the problem that the explosion-proof valve 40 is severely deformed after being subjected to an external force can be effectively improved.

[0076] Reference Figure 2b and Figure 5 , the explosion-proof valve 40 includes a second main body portion 43 and a second reinforcing portion 44. The second reinforcing portion 44 is located on the second main body portion 43. The second main body portion 43 includes a second notch portion 431. The second notch portion 431 defines at least part of the contour shape of the explosion-proof valve 40, and the second notch portion 431 is configured as a non-closed arc structure. The second reinforcing portion 44 is arranged close to the second notch portion 431.

[0077] By integrally forming the explosion-proof valve 40 with the side wall 213, the second notch portion 431 on the explosion-proof valve 40 is configured to be formed by stamping on the side wall 213, which can effectively improve the problem that the explosion-proof valve 40 is severely deformed after being subjected to an external force.

[0078] When a high-pressure air flow is generated inside the battery 20, the explosion-proof valve 40 deforms under the high-pressure force. Since the wall thickness where the second notch portion 431 is located is relatively thin, when the pressure value received by the second notch portion 431 exceeds the rated pressure value, the second notch portion 431 will break to form a pressure relief port, and the high-pressure air flow inside the battery 20 is discharged through the pressure relief port. By arranging the second strengthening portion 44 close to the second notch portion 431, the second strengthening portion 44 is used to enhance the structural strength of the explosion-proof valve 40, prevent the explosion-proof valve 40 from deforming severely when subjected to external extrusion. Further, the second strengthening portion 44 can also prevent the explosion-proof valve 40 from being separated from the side wall 213 as a whole after the second notch portion 431 breaks, thereby avoiding serious electrolyte spillage.

[0079] Continue to refer to Figure 5 , the second notch portion 431 includes a fourth section 4311, a fifth section 4312, and a sixth section 4313. One end of the fourth section 4311 is connected to the fifth section 4312, and the other end of the fourth section 4311 is connected to the sixth section 4313. One end of the fifth section 4312 is disposed opposite to one end of the sixth section 4313 to form a first gap 451, and the other end of the fifth section 4312 is disposed opposite to the other end of the sixth section 4313 to form a second gap 452.

[0080] The second strengthening portion 44 includes a fourth part 441 and a fifth part 442 that are spaced apart. The fourth part 441 is disposed within the first gap 451, and the fifth part 442 is located within the second gap 452.

[0081] By constructing the second notch portion 431 into three sections, and the fourth section 4311 of the second notch portion 431 is respectively connected to the fifth section 4312 and the sixth section 4313, when the fourth section 4311 deforms under high-pressure action, it will further drive the fifth section 4312 and the sixth section 4313 to deform and then break, so that the overall structure of the second notch portion 431 is conducive to pressure relief. By respectively arranging two parts of the strengthening portion 44 within the first gap 451 and the second gap 452 formed at both ends of the fifth section 4312 and both ends of the sixth section 4313, the explosion-proof valve 40 is maintained at an appropriate strength. When the explosion-proof valve 40 is subjected to external extrusion, the explosion-proof valve 40 will not deform severely. When the explosion-proof valve 40 is subjected to internal high pressure and reaches the rated high pressure, the second notch portion 431 of the explosion-proof valve 40 will break to form a pressure relief port, but the explosion-proof valve 40 as a whole will not be separated from the side wall 213, avoiding serious electrolyte spillage.

[0082] In a specific implementation, the fifth section 4312 and the sixth section 4313 of the second notched portion 431 are constructed as a non-closed arc shape, and the two ends of the fifth section 4312 and the sixth section 4313 are arranged opposite to each other, and the fourth section 4311 can be a straight line section, the fourth section 4311 is located on the central axis of the explosion-proof valve 40, one end of the fourth section 4311 is connected to the midpoint of the fifth section 4312, and the other end of the fourth section 4311 is connected to the midpoint of the sixth section 4313. In other optional examples, the fourth section 4311 can also be two connected arcs, the connection point of the two arcs is located at the center of the explosion-proof valve 40, the two arcs are arranged in back to back, and the two ends of each arc are respectively connected to the fifth section 4312 and the sixth section 4313, so that the overall structure of the explosion-proof valve 40 is a central symmetrical structure.

[0083] The fourth portion 441 and the fifth portion 442 of the second reinforcing portion 44 may be in a straight line shape or an arc shape.

[0084] The embodiment of the present application also provides a battery pack 1, which includes a box body 10 and at least two battery modules arranged inside the box body 10, wherein the at least two battery modules include an upper battery module and a lower battery module arranged along the height direction of the box body 10, thereby facilitating the improvement of the energy density of the battery pack. Each battery module includes a plurality of batteries, and at least one side wall of each battery is provided with an explosion-proof valve, and a pole is provided on the top wall of each battery.

[0085] For a battery pack having an upper battery module and a lower battery module, the multiple batteries in the two battery modules are arranged relatively densely. If an explosion-proof valve is provided on the top wall of the battery in each battery module, when thermal runaway occurs in the lower battery module, the explosion-proof valve of the lower battery module will open to discharge high-pressure airflow, which will further impact the upper battery module, thereby causing thermal runaway of the upper battery module, and very likely causing thermal runaway or even thermal explosion of the entire battery pack, thereby greatly reducing the safety performance of the entire battery pack.

[0086] In the embodiment of the present application, the explosion-proof valve of each battery in the battery pack arranged with the upper battery module and the lower battery module is set on the side wall of the battery. When the lower battery module has thermal runaway, the high-pressure airflow derived from the opening of the explosion-proof valve flows into both sides of the box, thereby effectively reducing the impact on the upper battery module.

[0087] refer to Figure 6The box body 10 of the battery pack 1 includes a plurality of side panels 11 enclosing a battery cavity 110, the side panels 11 include an inner panel and an outer panel, a hollow cavity is provided between the inner panel and the outer panel, the interval between the inner panel and the outer panel is provided as an exhaust channel 13, a plurality of through holes 14 are further provided on the inner panel, the plurality of through holes 14 are provided one-to-one correspondingly to the plurality of explosion-proof valves 40 provided on the plurality of batteries 20, and the through holes 14 are used to connect the explosion-proof valves 40 with the exhaust channel 13.

[0088] When thermal runaway occurs to some of the batteries 20 in the battery pack 1, the explosion-proof valves 40 where these batteries 20 are located are all arranged on the side wall 213. By correspondingly arranging through holes 14 and exhaust channels 13 on the side panels 11 of the box body 10, the high-pressure airflow discharged from the explosion-proof valves 40 where these batteries 20 are located after the valves are opened enters the exhaust channel 13 through the through holes 14, thereby reducing the impact of the thermal runaway of these batteries 20 on other batteries 20 inside the battery pack 1.

[0089] refer to Figure 7 The box body 10 also includes an end plate 12 connected to one end of the side plate 11. The end plate 12 is provided with a hollow inner cavity. The inner cavity of the end plate 12 is connected to the inner cavity of the side plate 11. At least one exhaust port 15 is also provided on the end plate 12. The exhaust port 15 is used to discharge the gas inside the exhaust channel 13. Alternatively, the exhaust port 15 can also be provided on the side plate 11. Alternatively, when there are multiple exhaust ports 15, a part of the exhaust ports 15 are provided on the side plate 11, and a part of the exhaust ports 15 are provided on the end plate 12. The position of the exhaust port 15 is designed and adjusted according to the equipment installation situation inside the battery accommodating cavity of the new energy vehicle or energy storage battery cabinet to which the battery pack 1 is applicable.

[0090] The high-pressure airflow discharged through the explosion-proof valve 40 escapes to the outside of the box body 10 through the through hole 14 , the exhaust channel 13 and the exhaust port 15 , thereby preventing thermal runaway from occurring inside the box body 10 .

[0091] Continue to refer Figure 6 and Figure 7 The battery cavity 110 and the electrical cavity 120 inside the box body 10 are separated. The battery cavity 110 is used to accommodate the battery module, and the electrical cavity 120 is used to accommodate the BMS. The exhaust channel 13 is arranged on one side of the battery cavity 110, and the exhaust channel 13 is arranged in the cavity wall of the battery cavity 110 and does not extend to the side where the electrical cavity 120 is located.

[0092] By configuring the exhaust passage 13 to extend only on one side of the battery chamber 110 , it is helpful to reduce the impact of the high-pressure airflow on the stable operation of components such as the BMS or the high-voltage box arranged inside the electrical chamber 120 .

[0093] Experimental verification

[0094] The present application further sets up examples and comparative examples to test the opening pressure of the battery. The setting parameters of the explosion-proof valves of the batteries provided in the examples and comparative examples are as shown in Table 1 and Table 2 below.

[0095] Test method for the opening pressure: Clamp the two sides with larger surface areas of the battery with steel plates to simulate the state of the battery in the battery pack. Drill a hole in the top wall of the battery, and inflate the battery through the hole at a pressure increasing rate of 0.03 MPa / s until the valve opens, and record the air pressure value.

[0096] Table 1 Record table for the opening pressure test of the explosion-proof valve of the battery

[0097]

[0098]

[0099] In Table 1, h is set as the height between the center of the explosion-proof valve and the top wall of the battery, and H is the height of the battery. According to the test data of the opening pressure in Table 1, it can be known that when h / H satisfies: 1 / 4 ≤ h / H ≤ 1 / 2, the opening pressure of the explosion-proof valve is 0.7 MPa to 0.9 MPa. When h / H is set to: h / H < 1 / 4 or h / H > 1 / 2, the opening pressure of the explosion-proof valve is in the range of 0.6 MPa to 1.0 MPa. Therefore, when the position of the explosion-proof valve satisfies 1 / 4 ≤ h / H ≤ 1 / 2, the opening pressure of the explosion-proof valve is relatively stable.

[0100] Table 2 Record table for the opening pressure test of the explosion-proof valve of the battery

[0101]

[0102] In Table 2, d is set as the distance between the center of the explosion-proof valve and the side of the battery, and W is the width of the side wall of the battery. According to the test data of the opening pressure in Table 2, it can be known that when d / W satisfies: 1 / 3 < d / w < 2 / 3, the opening pressure of the explosion-proof valve is 0.7 MPa to 0.9 MPa. When d / W is set to d / w greater than or equal to 1 / 3, or d / w greater than or equal to 2 / 3, the opening pressure of the explosion-proof valve is 0.6 MPa to 1.0 MPa. Therefore, when the position of the explosion-proof valve satisfies 1 / 3 < d / w < 2 / 3, the opening pressure of the explosion-proof valve is relatively stable.

[0103] The embodiments of the present invention have been introduced in detail above. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A battery, characterized in that, Comprising: A housing, the housing includes a top wall and a bottom wall arranged oppositely, and a plurality of side walls arranged between the top wall and the bottom wall, and at least one terminal post is arranged on the top wall; At least one explosion-proof valve, the explosion-proof valve is arranged on the side wall; Wherein, the distance between the center of the explosion-proof valve and the top wall is set as h, the height of the side wall is set as H, and h / H satisfies: 1 / 4 ≤ h / H ≤ 1 / 2.

2. The battery according to claim 1, wherein The side wall includes a first side and a second side which are oppositely arranged. The distance between the first side and the second side is set as the width w of the side wall. The distance from the center of the explosion-proof valve to the first side or the second side is d, and d / w satisfies: 1 / 3 < d / w < 2 / 3 。 3. The battery according to claim 2, characterized in that, The projected area of the explosion-proof valve on the side wall is m, the surface area of the side wall is M, and m / M satisfies: 0.025 ≤ m / M ≤ 0.

2.

4. The battery according to claim 3, characterized in that, h / H = 1 / 3, and / or, d / w = 1 / 2, and / or, m / M = 0.

08.

5. The battery according to any one of claims 1-4, characterized in that, The explosion-proof valve is separately arranged from the side wall and connected to the side wall. The explosion-proof valve includes a first main body portion and a first reinforcing portion located on the first main body portion. The first main body portion is provided with a first scoring portion, and the first scoring portion is configured as a non-closed arc shape, and the first reinforcing portion is configured to extend inside the first scoring portion.

6. The battery according to claim 5, characterized in that, The first scoring portion includes a first section, a second section and a third section. The first section is connected between one end of the second section and one end of the third section, and the other ends of the second section and the third section are arranged oppositely; the first reinforcing portion includes a first part, a second part and a third part. One end of the first part, one end of the second part and one end of the third part are connected to each other. The other end of the first part is close to the midpoint of the virtual connection line of the other ends of the second section and the third section. The other end of the second part is close to the second section, and the other end of the third part is close to the third section.

7. The battery according to any one of claims 1 to 4, characterized in that, The explosion-proof valve is configured to be integrally formed with the side wall. The explosion-proof valve includes a second main body portion and a second reinforcing portion located on the second main body portion. The second main body portion is provided with a second scoring portion, and the second reinforcing portion is arranged close to the second scoring portion.

8. The battery according to claim 7, characterized in that, The second scoring portion includes a fourth section, a fifth section and a sixth section. One end of the fourth section is connected to the fifth section, and the other end of the fourth section is connected to the sixth section. The two ends of the fifth section and the two ends of the sixth section are arranged oppositely to form a first interval and a second interval. The second reinforcing portion includes a fourth part and a fifth part arranged at intervals. The fourth part is arranged in the first interval, and the fifth part is arranged in the second interval.

9. A battery pack, characterized in that, The battery pack includes a box body and at least two battery modules arranged in the box body. Each battery module includes a plurality of batteries according to any one of claims 1-8. The battery module includes an upper battery module and a lower battery module arranged along the height direction of the box body.

10. The battery pack according to claim 9, wherein, The box body includes a side plate. The side plate is provided with an exhaust passage and a plurality of through holes. The plurality of through holes are arranged in one-to-one correspondence with the plurality of explosion-proof valves. The through holes are used to communicate the explosion-proof valve with the exhaust passage.

11. The battery pack according to claim 10, wherein, The box body further includes an end plate connected to one end of the side plate, and at least one exhaust port is further provided on the end plate for discharging the gas inside the exhaust passage; and / or, the exhaust port is arranged on the side plate.

12. The battery pack according to claim 10, characterized in that, The box body includes a battery chamber and an electrical chamber arranged at intervals. The battery chamber is used to accommodate the battery module, the electrical chamber is used to accommodate the battery management system, and the exhaust passage is arranged in the chamber wall of the battery chamber.

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