Batteries and electrical devices

Abstract

The present embodiment provides a battery and an electric device. The battery includes a housing including an electric cavity, a battery cell accommodated in the electric cavity, the battery cell having a pressure relief means on a first wall thereof, and a vent passage arranged to communicate with the inside of the battery cell through the pressure relief means when the pressure relief means is operated, where the battery satisfies 0.05wh / (kg·°C)≦a / b≦25wh / (kg·°C), where a is the gravimetric energy density of the battery cell and b is the melting point of a target structure for forming the vent passage. The battery and the electric device of the present embodiment can improve the safety performance of the battery.

Description

[Technical Field]

[0001] This application relates to the field of battery technology, and more particularly to batteries and electrical devices. [Background technology]

[0002] With the continuous advancement of battery technology, various new energy industries using batteries as energy storage devices are developing rapidly. In addition to improving battery performance, safety issues are also an issue that cannot be ignored in the development of battery technology. If battery safety issues cannot be addressed, the battery cannot be used. Therefore, how to improve battery safety is a technical issue that must be resolved as soon as possible in battery technology. Summary of the Invention

[0003] The present embodiment provides a battery and an electrical device that can improve the safety performance of the battery.

[0004] In a first aspect, there is provided a battery including a housing including an electrical cavity, a battery cell housed in the electrical cavity, the battery cell having a pressure release means provided on a first wall of the battery cell, and a discharge passage arranged to communicate with the interior of the battery cell through the pressure release means when the pressure release means is activated, wherein the battery satisfies 0.05wh / (kg·°C)≦a / b≦25wh / (kg·°C), where a is the weight energy density of the battery cell and b is the melting point of a target structure for forming the discharge passage.

[0005] Therefore, in the battery of the present embodiment, by rationally setting the a / b value, the waste matter inside the battery cell can be discharged in a timely manner, thereby improving the safety of the battery.

[0006] If the a / b value is too small, the melting point of the target structure will be set relatively high and the weight energy density a of the battery cell will be relatively small. Correspondingly, when thermal runaway occurs in the battery cell, the temperature of the discharged material will be low, and the temperature resistance of the target structure may exceed the temperature of the discharged material, which may result in the discharged material being restricted to the periphery of the pressure relief means and not being able to pass through the discharge passage for discharge. If the discharged material cannot be discharged in a timely manner away from the area where the pressure relief means is located, this may cause thermal diffusion between the battery cells, posing a risk of the battery exploding. Therefore, it is not preferable to make the a / b value small.

[0007] Conversely, a large a / b ratio is also undesirable. Due to structural limitations of the battery cell itself, there is an upper limit to the weight energy density a of the battery cell. Similarly, there is a lower limit to the melting point b of the target structure used to form the exhaust passage. Therefore, if the a / b ratio is too large, the b ratio will be too small for a given a value of a. This means that the melting point b of the target structure used to form the exhaust passage will be too low, further weakening the target structure. For example, if the melting point b of the target structure is too low, even a slight change in the battery temperature could cause the target structure to melt, further reducing the sealing of the exhaust passage. If the exhaust passage is destroyed and the battery cell experiences thermal runaway, this could affect the exhaust route and reduce the safety of the battery.

[0008] In some embodiments, when the battery satisfies 0.06Wh / (kg·°C)≦a / b≦15Wh / (kg·°C), the weight energy density a of the battery cell is more appropriate, and the melting point b of the target structure is neither too high nor too low, improving the performance of the battery cell and allowing internal emissions to be discharged in a timely and rapid manner when the battery cell experiences thermal runaway, thereby improving the safety of the battery.

[0009] In some embodiments, the weight energy density a of the battery cell ranges from 100 Wh / kg to 3505 Wh / kg. If the weight energy density a of the battery cell is too small, the battery's energy needs cannot be met, and if the weight energy density a of the battery cell is too large, the battery cell becomes difficult to process and is difficult to realize.

[0010] In some embodiments, the melting point b of the target structure ranges from 100°C to 2000°C. If the melting point b of the target structure is too low, the selectable materials are limited, the target structure strength is insufficient, and the exhaust passage strength may be reduced, which may lead to poor sealing. Conversely, if the melting point b of the target structure is too high, exhaust from the battery cells may not be able to be exhausted through the exhaust passage in a timely manner, which may cause thermal diffusion between the battery cells and affect the safety of the battery.

[0011] In some embodiments, the electrical cavity includes a second wall, and the first wall faces the second wall. That is, the pressure release means of the battery cell faces the wall of the electrical cavity, not the other battery cells. This makes it easy to provide a relief structure in the wall of the electrical cavity to provide relief space for deformation of the pressure release means, improves the space utilization rate of the battery, reduces the risk that a battery cell that has experienced thermal runaway will cause thermal runaway in other battery cells, and improves the safety of the battery.

[0012] In some embodiments, the target structure includes the second wall, which allows the effluent discharged from the pressure release means to pass through the second wall and be discharged from the battery cell. By appropriately setting the melting point of the second wall, the effluent discharged from the pressure release means can quickly destroy the second wall and be discharged from the battery cell, further improving the safety of the battery.

[0013] In some embodiments, the exhaust passage includes a first passage, which is used to exhaust the exhaust discharged from the pressure relief means to the electrical cavity. When the battery includes a first passage, at least a portion of the exhaust discharged through the pressure relief means of the battery cell passes through the first passage and is discharged to the electrical cavity in which the battery cell is located, which is simple in structure and easy to implement.

[0014] In some embodiments, the battery further includes a connecting structure, the connecting structure being disposed between the first wall and the second wall and used to form at least a portion of the first passageway, and the target structure includes the connecting structure. The connecting structure forms at least a portion of the first passageway, and when thermal runaway is not occurring in the battery cell, the connecting structure provides relative fixation between the first wall and the second wall and sealing between the first wall and the second wall. By rationally designing the specific shape and position of the connecting structure, the position of the first passageway can be adjusted and directional discharge of effluent passing through the first passageway can be achieved, thereby improving battery safety. Furthermore, when the target structure includes the connecting structure, by rationally designing the melting point of the connecting structure, effluent passing through the pressure release means can be smoothly discharged through at least a portion of the first passageway formed by the connecting structure, thereby improving battery safety.

[0015] In some embodiments, the connection structure is provided with a flow path, and the first passage includes the flow path. The effluent discharged through the pressure release means can pass through the flow path and be discharged into the electrical cavity. In this way, by rationally setting the position of the flow path, directional discharge of the effluent can be achieved, reducing the impact of the effluent on individual components in the electrical cavity and further improving the safety of the battery.

[0016] In some embodiments, the connection structure is used to break when the pressure release means is activated to form a gap between the first wall and the second wall, and the first passage includes the gap. In this way, the target structure for forming the first passage can include the connection structure, and by rationally selecting the material of the connection structure, an appropriate melting point of the connection structure can be obtained, and the connection structure is broken when the pressure release means is activated to further form a gap and form the first passage. The connection structure does not require any additional structure, is simpler, and can also ensure the sealing of the battery cell during normal use.

[0017] In some embodiments, the connecting structure is provided with a relief opening corresponding to the pressure release means, and the relief opening provides a deformation space (space for deformation of the pressure release means) when the pressure release means operates, preventing the connecting structure from blocking the pressure release means and preventing the pressure release means from not operating in a timely manner, and allowing the relief opening to quickly discharge exhaust that has passed through the pressure release means.

[0018] In some embodiments, the vent passage includes a second passage, the second passage being used to vent effluent vented by the pressure relief means from the electrical cavity.

[0019] In some embodiments, the second wall is provided with a pressure relief area corresponding to the pressure relief means, and the pressure relief area is used to form at least a part of the second passage. The second wall is a wall of the electrical cavity, and the effluent discharged through the pressure relief means can be discharged from the electrical cavity through the pressure relief area of ​​the second wall. That is, the pressure relief area is at least a part of the second passage for discharging the effluent. For example, the effluent may be discharged into a collection cavity to prevent a large amount of effluent from entering the electrical cavity, leading to short circuits between battery cells or thermal diffusion, and further affecting the safety of the battery.

[0020] In some embodiments, the pressure relief area is a through-hole penetrating the second wall, the through-hole extending in the thickness direction of the second wall, and the second passageway includes the through-hole. When the pressure relief area is a through-hole, processing is facilitated and effluents discharged through the pressure relief means can be quickly discharged. However, when the pressure relief area is a through-hole, the pressure relief means is exposed, which makes the pressure relief means susceptible to external environmental influences during use of the battery, potentially leading to breakdown of the pressure relief means.

[0021] In some embodiments, the battery further includes a sealing structure, the sealing structure being used to seal the through-hole and being broken when the pressure release means is activated to form at least a part of the second passageway through the through-hole, and the target structure including the sealing structure. When the pressure release area is the through-hole, the melting point of the sealing structure can be appropriately set to maintain the sealability of the electrical cavity and protect the pressure release means from the influence of the external environment during normal use of the battery cell. Meanwhile, when thermal runaway occurs in the battery cell, the sealing structure can be broken in a timely manner to expose the through-hole and form the second passageway, allowing the waste from the battery cell to pass through the through-hole and be discharged from the electrical cavity, thereby avoiding thermal runaway and improving the safety of the battery.

[0022] In some embodiments, the sealing structure is provided on a surface of the second wall facing the first wall, and / or the sealing structure is provided on a surface of the second wall facing away from the first wall. When the sealing structure is provided on the surface of the second wall facing the first wall, the sealing structure is close to the pressure relief means and can be quickly broken by the discharge from the pressure relief means, avoiding affecting the operation of the pressure relief means and allowing the discharge to be discharged to the collection cavity in a timely manner. When the sealing structure is provided on the surface of the second wall facing away from the first wall, the distance between the pressure relief means and the sealing structure provides a deformation space for the operation of the pressure relief means and avoiding affecting the pressure relief means.

[0023] In some embodiments, the pressure relief region is a weakened region of the second wall, which is ruptured to form at least a portion of the second passageway when the pressure relief means is activated. When the pressure relief means is activated, the weakened region is ruptured, allowing effluent from the battery cell having the pressure relief means to pass through the weakened region and escape from the electrical cavity, for example, to enter the collection cavity. By providing the pressure relief region as a weakened region, the second wall is sealed when the pressure relief means is not activated, for example, during normal battery use, effectively protecting the pressure relief means from being ruptured and broken by external forces. Furthermore, when thermal runaway occurs in the battery cell, the weakened region is ruptured in a timely manner to allow effluent to escape from the electrical cavity, avoiding thermal runaway and improving battery safety.

[0024] In some embodiments, when the target structure includes the weakened region, the melting point of the weakened region can be reasonably set so that the weakened region has sufficient strength during normal use of the battery cell, maintains the sealing of the electrical cavity, and protects the pressure relief means from the influence of the external environment. Meanwhile, when thermal runaway occurs in the battery cell, the weakened region can be broken in a timely manner, for example, melted in a timely manner to form a second passage, so that the discharged matter of the battery cell can pass through the broken pressure relief region and be discharged from the electrical cavity, thereby avoiding thermal runaway and improving the safety of the battery.

[0025] In some embodiments, the thickness of the weakened region is less than the thickness of a region of the second wall surrounding the weakened region, and reducing the thickness of the weakened region reduces its strength, allowing the effluent to quickly destroy the weakened region by melting and breaking, and allowing the effluent to be evacuated in a timely manner.

[0026] In some embodiments, the second wall is provided with a groove corresponding to the pressure release means, with an opening facing the pressure release means, and the weakened area is the bottom wall of the groove. In this way, the opening of the groove corresponds to the pressure release means, and the inside of the groove provides a deformation space for the pressure release means, and by providing the bottom wall as the weakened area, processing is facilitated.

[0027] In some embodiments, the housing further includes a collection cavity for collecting the effluent discharged through the second passage when the pressure release means is activated. The collection cavity can collect and / or process the effluent in a concentrated manner and discharge the effluent to the outside of the battery. For example, the collection cavity may contain a liquid, such as a cooling medium, for further lowering the temperature of the effluent received in the collection cavity, or a component for containing the liquid may be provided.

[0028] In some embodiments, the battery further includes an isolation member for isolating the electrical cavity from the collection cavity, wherein the isolation member is employed to isolate the electrical cavity from the collection cavity, i.e., the electrical cavity housing the battery cells and bus components and the collection cavity collecting waste are separated to avoid mutual influence therebetween.

[0029] In some embodiments, the isolation piece is used to form at least part of the second passageway, such that effluent passing through the pressure relief means can pass through the isolation piece and out of the electrical cavity, for example directly into a collection cavity.

[0030] In a second aspect, there is provided an electrical device including a battery according to the first aspect, the battery being used to provide electrical energy to the electrical device.

[0031] In some embodiments, the electrical device is a vehicle, a watercraft, or a spacecraft. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a structural schematic diagram of a vehicle disclosed in an embodiment of the present application; [Figure 2] 1 is a structural schematic diagram of a type of battery disclosed in an embodiment of the present application. [Figure 3] FIG. 2 is a structural schematic diagram of another battery disclosed in an embodiment of the present application. [Figure 4] 1 is an exploded structural schematic diagram of a battery disclosed in an embodiment of the present application. [Figure 5] 1 is a schematic diagram of the local structure of a battery disclosed in an embodiment of the present application. [Figure 6] FIG. 2 is a structural schematic diagram of another battery disclosed in an embodiment of the present application. [Figure 7] FIG. 2 is a structural schematic diagram of another battery disclosed in an embodiment of the present application. [Figure 8] FIG. 2 is a structural schematic diagram of another battery disclosed in an embodiment of the present application.

[0033] In the drawings, the figures may not be drawn to scale. DETAILED DESCRIPTION OF THE INVENTION

[0034] The following describes the embodiments of the present application in more detail with reference to the drawings and examples. The detailed description of the following examples and the drawings are used to exemplify the principles of the present application, but cannot be used to limit the scope of the present application, i.e., the present application is not limited to the described examples.

[0035] In the description of this application, unless otherwise specified, "multiple" means two or more (including two), and any direction or positional relationship indicated by terms such as "up," "down," "left," "right," "inside," and "outside" is intended solely to facilitate and simplify the description of this application and does not indicate or imply that the depicted devices or elements must have a particular orientation, be configured, or operate in a particular direction, and should not be understood as limiting this application. Furthermore, terms such as "first," "second," and "third" are merely descriptive and should not be understood as indicating or implying relative importance. "Perpendicular" does not mean perpendicular in the strict sense, but has a margin of error. "Parallel" does not mean parallel in the strict sense, but has a margin of error.

[0036] Any directional terms used in the following description refer to the directions shown in the drawings and do not limit the specific structure of the present application. In the description of the present application, unless otherwise specified or limited, technical terms such as "attached," "connected," and "connection" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration, and may be directly connected or indirectly connected via an intermediate medium. Those skilled in the art will be able to understand the specific meanings of these terms in the present application according to the specific circumstances.

[0037] In the embodiments of the present application, the same reference numerals denote the same parts, and for the sake of brevity, detailed descriptions of the same parts will be omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various parts in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely examples and do not limit the present application in any way.

[0038] In the present application, the battery cells may include lithium ion secondary batteries, lithium ion primary batteries, lithium-sulfur batteries, sodium lithium ion batteries, sodium ion batteries, magnesium ion batteries, etc., but are not limited thereto in the embodiments of the present application. The battery cells may be cylindrical, flat, rectangular, or have other shapes, but are not limited thereto in the embodiments of the present application. Battery cells are generally broadly divided into three types depending on the packaging method: prismatic battery cells, prismatic battery cells, and soft pouch battery cells, but are not limited thereto in the embodiments of the present application.

[0039] The battery referred to in the embodiments of this application refers to a single physical module containing one or more battery cells to provide higher voltage and / or capacity. For example, the battery referred to in this application may include a battery module or a battery pack. The battery typically includes a housing for packaging one or more battery cells. The housing can prevent liquids and other foreign objects from affecting the charging and discharging of the battery cells.

[0040] A battery cell includes an electrode assembly consisting of a positive electrode sheet, a negative electrode sheet, and a separator, and an electrolyte. The battery cell operates primarily through the transfer of metal ions between the positive and negative electrode sheets. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The portion of the current collector not coated with the positive electrode active material layer protrudes from the portion coated with the positive electrode active material layer, and the portion of the current collector not coated with the positive electrode active material layer is called a positive electrode tab. For example, in a lithium-ion battery, the positive electrode current collector may be made of aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is applied to the surface of the negative electrode current collector, and the current collector not coated with the negative electrode active material layer protrudes from the current collector coated with the negative electrode active material layer. The current collector not coated with the negative electrode active material layer is called a negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. To allow a large current to pass without fusing, the positive electrode tab is formed by stacking multiple pieces, and the negative electrode tab is formed by stacking multiple pieces. The separator may be made of polypropylene (PP) or polyethylene (PE), for example. The electrode assembly may have a wound structure or a stacked structure, and the embodiments of the present application are not limited thereto.

[0041] The development of battery technology requires simultaneous consideration of various design factors, such as performance parameters like energy density, cycle life, discharge capacity, and charge / discharge rate, as well as battery safety. Safety hazards for batteries primarily arise during the charging and discharging processes. To improve battery safety, a pressure relief device is typically provided for battery cells. The pressure relief device is an element or component that operates to release the internal pressure or temperature of a battery cell when the internal pressure or temperature reaches a predetermined threshold. The predetermined threshold can be adjusted according to different design needs. For example, the predetermined threshold may be determined by one or more materials of the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell. The pressure relief device may be a pressure- or temperature-sensitive element or structure, i.e., the pressure relief device operates to form a passage for releasing the internal pressure or temperature when the internal pressure or temperature of the battery cell reaches a predetermined threshold.

[0042] In the design of conventional pressure relief means, attention is focused on releasing the high pressure and heat inside the battery cell, that is, discharging the discharged material from the battery cell to the outside of the battery cell through the pressure relief means. However, how to design a discharge path for the high-temperature and high-pressure discharged material after it has been discharged from the battery cell so that the discharged material can be discharged in a timely and smooth manner to avoid causing further safety issues to the battery is an issue that needs to be resolved urgently.

[0043] Therefore, the present embodiment provides a battery and an electric device that can solve the above-mentioned problems. The battery of the present embodiment includes a housing, a battery cell, and a vent passage. The battery cell is accommodated in an electrical cavity of the housing. A pressure release means is provided on a first wall of the battery cell. When the pressure release means is activated, the vent passage is connected to the interior of the battery cell through the pressure release means, so that effluent inside the battery cell can be discharged through the pressure release means and the vent passage. The battery satisfies 0.05wh / (kg·°C)≦a / b≦25wh / (kg·°C), where a is the weight energy density of the battery cell and b is the melting point of the target structure for forming the vent passage. If the a / b value is too small, the melting point of the target structure will be set relatively high and the weight energy density of the battery cell will be relatively small. Correspondingly, the temperature of the effluent discharged when thermal runaway occurs in the battery cell will be low, and the temperature resistance of the target structure may exceed the temperature of the effluent, causing the effluent to be restricted around the pressure relief means and unable to pass through the discharge passage for discharge. If the effluent cannot be discharged in a timely manner away from the area where the pressure relief means is located, it will cause thermal diffusion between the battery cells, posing a risk of the battery exploding. Therefore, it is not preferable to make the a / b value small.

[0044] Conversely, a large a / b ratio is also undesirable. Due to structural limitations of the battery cell itself, there is an upper limit to the weight energy density of the battery cell. Similarly, there is a lower limit to the melting point of the target structure forming the exhaust passage. Therefore, if the a / b ratio is too large, the b ratio will be too small for a given a value of a. That is, the melting point b of the target structure forming the exhaust passage will be too low, further resulting in insufficient strength of the target structure. For example, if the melting point b of the target structure is too low, even a slight change in the battery temperature may cause the target structure to melt, further reducing the sealing performance of the exhaust passage. If the exhaust passage is destroyed and the battery cell experiences thermal runaway, this may affect the exhaust path and reduce battery safety. Therefore, it is undesirable to make the a / b ratio in the present examples too large or too small.

[0045] The technical solutions described in the embodiments of the present application are applicable to various electrical equipment that uses batteries.

[0046] The electric device may be a vehicle, a mobile phone, a portable device, a laptop computer, a boat, a spacecraft, an electric toy, or an electric tool. The vehicle may be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range-extended electric vehicle, etc. The spacecraft may include an airplane, a rocket, a space shuttle, a spaceship, etc. The electric toy may be a game console, an electric toy car, an electric toy boat, an electric toy airplane, or other stationary or mobile electric toy. The electric tool may be, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, an electric planer, or other metal cutting power tools, grinding power tools, assembly power tools, or railroad power tools. The embodiments of the present application do not have any particular limitations on the electric equipment.

[0047] In the following embodiments, for convenience of explanation, an electric device will be described using a vehicle as an example.

[0048] For example, FIG. 1 shows a structural schematic diagram of a vehicle 1 according to one embodiment of the present application. The vehicle 1 may be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range-extender electric vehicle. A motor 40, a controller 30, and a battery 10 may be provided inside the vehicle 1. The controller 30 controls the battery 10 to supply power to the motor 40. For example, the battery 10 may be provided at the bottom, top, or rear of the vehicle 1. The battery 10 is used to power the vehicle 1, for example, as an operating power source for the vehicle 1. The battery 10 may be applied to the electrical system of the vehicle 1, for example, to control the power required for starting, navigating, and driving the vehicle 1. In another embodiment of the present application, the battery 10 not only functions as an operating power source for the vehicle 1 but also as a power source for driving the vehicle 1, thereby providing driving power to the vehicle 1 as a replacement or partial replacement for gasoline or natural gas.

[0049] To meet various power consumption needs, a battery may include multiple battery cells, which may be connected in series, parallel, or series-parallel, where series-parallel connection refers to a combination of series and parallel connections. A battery is also called a battery pack. For example, multiple battery cells may be connected in series, parallel, or series-parallel to form a battery module, and then multiple battery modules may be connected in series, parallel, or series-parallel to form a battery. That is, multiple battery cells may directly form a battery, or may first form a battery module, and then the battery module may form a battery.

[0050] 2 is a structural schematic diagram of a battery 10 in an embodiment of the present invention. As shown in Fig. 2, the battery 10 may include a housing 11 including an electrical cavity 11a, a battery cell 20 housed in the electrical cavity 11a, the battery cell 20 having a pressure release means 211 provided on a first wall 21 of the battery cell 20, and a discharge passage 13 arranged to communicate with the interior of the battery cell 20 through the pressure release means 211 when the pressure release means 211 is activated, wherein the battery satisfies 0.05wh / (kg·°C)≦a / b≦25wh / (kg·°C), where a is the weight energy density of the battery cell 20 and b is the melting point of the target structure for forming the discharge passage 13.

[0051] As will be understood, as shown in FIG. 2 , the electrical cavity 11a of the housing 11 of the present embodiment is used to accommodate at least one battery cell 20, i.e., the electrical cavity 11a provides a mounting space for the battery cell 20. The electrical cavity 11a may be sealed or unsealed. The shape of the electrical cavity 11a may be determined depending on the one or more battery cells 20 to be accommodated. For example, although FIG. 2 shows the electrical cavity 11a as a rectangular parallelepiped, the present embodiment is not limited thereto.

[0052] As can be understood, the pressure release means 211 of the present embodiment is used to release the internal pressure or temperature of the battery cell 20 by being activated when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold. The value of the threshold may vary depending on design needs. The threshold may depend on one or more materials of the positive electrode sheet, the negative electrode sheet, the electrolyte, and the separator in the battery cell 20.

[0053] The term "operation" as used herein means that the pressure relief means 211 operates or is activated to a certain state, thereby releasing the internal pressure and temperature of the battery cell 20. Operation by the pressure relief means 211 may include, but is not limited to, cases where at least a portion of the pressure relief means 211 is damaged, crushed, broken, or opened. When the pressure relief means 211 operates, high-temperature and high-pressure materials inside the battery cell 20 are discharged to the outside from the activated location. In this way, by releasing the pressure or temperature of the battery cell 20 when the pressure or temperature is controllable, it is possible to avoid potentially more serious accidents.

[0054] The emissions from the battery cell 20 referred to in this application include, but are not limited to, electrolyte, dissolved or decomposed positive and negative electrode sheets, separator fragments, high-temperature and high-pressure gases due to reactions, flames, etc.

[0055] The pressure release means 211 according to the present embodiment is provided in the first wall 21 of the battery cell 20, and may be a part of the first wall 21, or may be a separate structure from the first wall 21 and fixed to the first wall 21 by, for example, welding. For example, when the pressure release means 211 is a part of the first wall 21, the pressure release means 211 can be formed by providing a notch in the first wall 21, and the thickness of the first wall 21 corresponding to the notch is smaller than the thickness of the other areas of the pressure release means 211 excluding the notch. The notch is the thinnest part of the pressure release means 211. When the internal pressure of the battery cell 20 increases due to excessive gas generated by the battery cell 20 and reaches a threshold value, or when the internal temperature of the battery cell 20 increases due to heat generated by an internal reaction of the battery cell 20 and reaches a threshold value, the pressure release means 211 can burst at the cut location to connect the inside and outside of the battery cell 20, and the gas pressure and temperature can be released to the outside by the rupture of the pressure release means 211, thereby avoiding the explosion of the battery cell 20.

[0056] Furthermore, for example, the pressure release means 211 may be a separate structure from the first wall 21, and the pressure release means 211 may take the form of, for example, an explosion-proof valve, a gas valve, a pressure release valve, or a safety valve, specifically, a pressure-sensitive or temperature-sensitive element or structure; that is, when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold, the pressure release means 211 operates, or a weak structure provided in the pressure release means 211 is broken to form an opening or passage for releasing the internal pressure or temperature.

[0057] In this embodiment, the battery 10 satisfies the following relationship: 0.05Wh / (kg·°C)≦a / b≦25Wh / (kg·°C), where a is the weight energy density of the battery cell, and b is the melting point of the target structure for forming the exhaust passage. By rationally setting the a / b value, exhaust from inside the battery cell 20 can be exhausted in a timely manner, improving the safety of the battery 10.

[0058] If the a / b value is too small, the melting point b of the target structure will be set relatively high, and the weight energy density a of the battery cell 20 will be relatively small. Correspondingly, the temperature of the effluent discharged when the battery cell 20 experiences thermal runaway will be low, and the temperature resistance of the target structure may exceed the temperature of the effluent, causing the effluent to be restricted around the pressure release means and unable to pass through the discharge passage 13 for discharge. If the effluent cannot be discharged in a timely manner away from the area where the pressure release means 211 is located, it will cause thermal diffusion between the battery cells 20, posing a risk of the battery 10 exploding. Therefore, it is not preferable to make the a / b value small.

[0059] Conversely, a large a / b ratio is also undesirable. Due to structural limitations of the battery cell 20 itself, the weight energy density a of the battery cell 20 has an upper limit. Similarly, the melting point b of the target structure forming the exhaust passage 13 also has a lower limit. Therefore, if the a / b ratio is too large, the b ratio will be too small for a given a value of a. That is, the melting point b of the target structure forming the exhaust passage 13 will be too low, further resulting in insufficient strength of the target structure. For example, if the melting point b of the target structure is too low, even a slight change in the battery temperature could cause the target structure to melt, reducing the sealing stability of the exhaust passage 13. Furthermore, if the exhaust passage 13 is destroyed and the battery cell 20 experiences thermal runaway, this could affect the exhaust path for the exhaust, potentially reducing the safety of the battery 10.

[0060] Therefore, it is not preferable that the value of a / b in the present embodiment is too large or too small. For example, the values ​​of a / b are 0.05wh / (kg·°C), 0.06wh / (kg·°C), 0.08wh / (kg·°C), 0.1wh / (kg·°C), 0.18wh / (kg·°C), 0.4wh / (kg·°C), 0.5wh / (kg·°C), 0.64wh / (kg·°C), 1wh / (kg·°C), 1.4wh / (kg·°C), 3wh / (kg·°C), 4wh / (kg·°C), 5wh / (kg·°C), 6wh / (kg·°C), 7wh / (kg·°C), 8wh / (kg·°C), 9wh / (kg·°C), 10wh / (kg·°C), 11wh / (kg·°C), 12wh / (kg·°C), 13wh / (kg·°C), 14wh / (kg·°C), 15wh / (kg·°C), 16wh / (kg·°C), 17wh / (kg·°C), 18wh / (kg·°C), 19wh / (kg·°C), 20wh / (kg·°C), 22wh / (kg·°C), 23wh / (kg·°C), 24wh / (kg·°C), 25wh / (kg·°C), 26wh / (kg·°C), 27wh / (kg·°C), 28wh / (kg·°C), 29wh / (kg·°C), 30wh / (kg·°C), 31wh / (kg·°C), 32wh / (kg·°C), 33 It may be set to h / (kg·℃), 5wh / (kg·℃), 7wh / (kg·℃), 9wh / (kg·℃), 11wh / (kg·℃), 13wh / (kg·℃), 15wh / (kg·℃), 17wh / (kg·℃), 19wh / (kg·℃), 21wh / (kg·℃), 23wh / (kg·℃) or 25wh / (kg·℃).

[0061] For example, if the battery 10 satisfies 0.06 wh / (kg·°C)≦a / b≦15 wh / (kg·°C), the weight energy density a of the battery cell 20 is appropriate and the melting point b of the target structure is neither too high nor too low, improving the performance of the battery cell 20 and enabling internal emissions to be discharged in a timely and rapid manner when the battery cell 20 experiences thermal runaway, thereby improving the safety of the battery 10.

[0062] In the present embodiment, the value of the weight energy density a of the battery cell 20 may be set according to the actual application. For example, the range of the value of the weight energy density a of the battery cell 20 is 100 Wh / kg to 3505 Wh / kg. If the weight energy density a of the battery cell 20 is too small, the energy needs of the battery 10 cannot be met, and if the value of the weight energy density a of the battery cell 20 is too large, the processing of the battery cell 20 becomes more difficult, making it difficult to realize. Therefore, the weight energy density a of the battery cell 20 may be set to typically 100 Wh / kg, 120 Wh / kg, 150 Wh / kg, 200 Wh / kg, 250 Wh / kg, 300 Wh / kg, 350 Wh / kg, 400 Wh / kg, 420 Wh / kg, 450 Wh / kg, 500 Wh / kg, 800 Wh / kg, 1000 Wh / kg, 1500 Wh / kg, 2000 Wh / kg, 2500 Wh / kg, or 3505 Wh / kg. For example, depending on the performance of the battery 10 and the difficulty of processing it, the weight energy density a of the battery cell 20 may be set to a range of 100 Wh / kg to 1500 Wh / kg.

[0063] In the present embodiment, the melting point b of the target structure of the battery 10 may be set according to the actual application. For example, the melting point b of the target structure may range from 100°C to 2000°C. If the melting point b of the target structure is too low, the materials that can be selected are limited, and the target structure may have insufficient strength, which may further reduce the strength of the exhaust passage and lead to poor sealing. Conversely, if the melting point b of the target structure is too high, the exhaust from the battery cells 20 may not be able to be discharged in a timely manner through the exhaust passage 13, and may further cause thermal diffusion between the battery cells 20, which may affect the safety of the battery 10. Therefore, the melting point b of the target structure may be set to typically 100°C, 200°C, 300°C, 400°C, 500°C, 600°C, 660°C, 700°C, 800°C, 900°C, 1000°C, 1200°C, 1400°C, 1500°C, 1600°C, 1700°C, 1800°C, or 2000°C. Also, for example, taking into consideration the temperature of the discharged material when the battery cell 20 experiences thermal runaway, the melting point b of the target structure may be set to a range of 100°C to 1700°C.

[0064] The following describes, by way of example, the discharge passage 13 and target structure according to an embodiment of the present invention with reference to the drawings.

[0065] 2, the electrical cavity 11a according to the present embodiment can be used to accommodate other components, such as a bus component 30. That is, the electrical cavity 11a provides a mounting space for the battery cells 20 and the bus component 30. The bus component 30 is used to electrically connect multiple battery cells 20 together, for example, in series, parallel, or series-parallel connection. The bus component 30 can be connected to electrode terminals 212 of the battery cells 20 to electrically connect the battery cells 20 together. In some embodiments, the bus component 30 can be fixed to the electrode terminals 212 of the battery cells 20 by welding.

[0066] Each battery cell 20 according to the present embodiment may include at least two electrode terminals 212, each of which includes at least one positive electrode terminal 212a and at least one negative electrode terminal 212b. The electrode terminals 212 according to the present embodiment are electrically connected to tabs of an electrode assembly inside the battery cell 20 to export electrical energy.

[0067] As can be understood, in the present embodiment, each electrode terminal 212 may be provided on any one wall, and multiple electrode terminals 212 may be provided on the same wall or different walls of the battery cell 20. For example, as shown in FIG. 2, if each battery cell 20 includes two electrode terminals 212, the two electrode terminals 212 may be located on the same wall. Specifically, as shown in FIG. 2, the two electrode terminals 212 may be located on a wall opposite the first wall 21. In this way, when the pressure release means 211 of the first wall 21 operates, the two electrode terminals 212 are not affected or only affected to a small extent, thereby preventing short circuits between the battery cells 20. Alternatively, the two electrode terminals 212 may be located on other walls; the present embodiment is not limited to this.

[0068] Similarly, for example, in the case where each battery cell 20 includes two electrode terminals 212, unlike the situation shown in FIG. 2, the two electrode terminals 212 may be located on different walls. FIG. 3 shows another structural schematic diagram of the battery 10 according to the present embodiment. As shown in FIG. 3, the two electrode terminals 212 of the battery cell 20 may be located on two opposing walls of the battery cell 20, respectively. Alternatively, the two electrode terminals 212 of the battery cell 20 may be located on two intersecting walls, and the present embodiment is not limited to this.

[0069] As can be understood, as shown in Figures 2 and 3, the exhaust passage 13 according to the present embodiment may include a first passage 131 and / or a second passage 132, wherein the first passage 131 is used to exhaust the exhaust discharged from the pressure relief means 211 to the electrical cavity 11a, and the second passage 132 is used to exhaust the exhaust discharged from the pressure relief means 211 from the electrical cavity 11a.

[0070] If the battery 10 includes the first passage 131 but not the second passage 132, the effluent discharged through the pressure release means 211 of the battery cells 20 passes through the first passage 131 and is discharged into the electrical cavity 11a in which the battery cells 20 are located, eliminating the need to provide a separate passage for discharging the effluent from the electrical cavity 11a, and simplifying the structure of the housing 11. However, since the effluent discharged from the battery cells 20 has high temperature and pressure characteristics and may contain a large amount of metal particles, discharging the effluent directly into the electrical cavity 11a is likely to cause short circuits between the battery cells 20, thermal diffusion, and even battery 10 explosion, which is detrimental to the safety of the battery 10.

[0071] Therefore, the battery 10 may be provided with a second passage 132. Specifically, if the battery 10 includes the second passage 132 but does not include the first passage 131, all of the effluent discharged through the pressure release means 211 of the battery cells 20 must pass through the second passage 132 to be discharged from the electrical cavity 11b, and the effluent will have no effect on the battery cells 20 in the electrical cavity 11b, effectively avoiding thermal diffusion and short-circuiting of the battery cells 20 due to the effluent, and further improving the safety of the battery 10. In addition, the second passage 132 allows the effluent from the battery cells 20 to be collected in a concentrated manner, preventing the effluent from affecting other components.

[0072] Alternatively, the battery 10 may include both the first passage 131 and the second passage 132. When the battery cell 20 experiences thermal runaway or other abnormality, high-temperature and high-pressure effluent generated within the battery cell 20 is discharged toward the pressure relief means 211 of the battery cell 20. This effluent is typically very powerful and destructive. If only one passage is provided, it may pierce the structure of the passage or one or more structures surrounding the passage, causing further safety issues. Therefore, it is conceivable to split the effluent discharged through the pressure relief means 211 into two passages for joint discharge. This not only increases the discharge rate and reduces the risk of explosion of the battery 10, but also achieves directional and dispersed discharge, thereby avoiding the impact of the effluent on other components and improving the safety and stability of the battery 10.

[0073] For convenience of explanation, the present embodiment will be described mainly by taking an example in which the discharge passage 13 of the battery 10 includes a first passage 131 and a second passage 132, but the present embodiment is not limited thereto.

[0074] Specifically, as shown in FIGS. 2 and 3 , the housing 11 of the present embodiment may further include a collection cavity 11b used to collect and / or process effluent discharged through the pressure release means 211 when the pressure release means 211 is activated. For example, the collection cavity 11b may be used to collect effluent discharged through the second passage 132 when the pressure release means 211 is activated and discharge the effluent to the outside of the battery 10. The collection cavity 11b is used to collect effluent and may be sealed or unsealed. In some embodiments, the collection cavity 11b may contain air or other gas. Optionally, the collection cavity 11b may contain a liquid, such as a cooling medium, to further cool the effluent entering the collection cavity 11b, or a component containing the liquid may be provided. Optionally, the gas or liquid in the collection cavity 11b may flow circulatoryly.

[0075] Optionally, as shown in Figures 2 and 3, the battery 10 of this embodiment further includes an isolation member 114 for isolating the electrical cavity 11a and the collection cavity 11b. Here, "isolation" means separation, and does not necessarily mean sealing. Specifically, the isolation member 114 is used to isolate the electrical cavity 11a and the collection cavity 11b, i.e., the electrical cavity 11a for accommodating the battery cells 20 and the collection cavity 11b for collecting waste are separated from each other.

[0076] In the present embodiment, the isolation component 114 may include a wall shared by the electrical cavity 11 a and the collection cavity 11 b. As shown in Figures 2 and 3, the isolation component 114 (or a part thereof) can directly function as a wall shared by the electrical cavity 11 a and the collection cavity 11 b, thus making it possible to minimize the distance between the electrical cavity 11 a and the collection cavity 11 b, thereby saving space and improving the space utilization rate of the housing 11.

[0077] Optionally, the isolation component 114 of the present embodiment may be a thermal management component, which is used to regulate the temperature of the battery cell 20. Specifically, the isolation component 114 is used to accommodate a fluid for regulating the temperature of the battery cell 20. When lowering the temperature of the battery cell 20, the isolation component 114 may accommodate a cooling medium to regulate the temperature of the battery cell 20. In this case, the isolation component 114 may also be referred to as a cooling component, cooling system, or cooling plate. The isolation component 114 may also be used for heating, although this embodiment is not limited thereto. Optionally, the fluid in the isolation component 114 may circulate to achieve a better temperature regulation effect.

[0078] As can be understood, the housing 11 of the present embodiment can be realized in various ways, and the present embodiment is not limited thereto. For example, taking Figures 2 and 3 as an example, for the electrical cavity 11a, the housing 11 can include a first cover 110 having an opening, and an isolation piece 114 can be fitted to the opening of the first cover 110. Thus, the wall forming the electrical cavity 11a includes the first cover 110 and the isolation piece 114. The first cover 110 can also be realized in various ways. For example, the first cover 110 may be a hollow, one-piece structure with an open end, or the first cover 110 may include a first portion and a second portion with two opposing sides each having an opening, the first portion fitting over the opening on one side of the second portion to form the open-ended first cover 110, and the isolation member 114 fitting over the opening on the other side of the second portion to form the electrical cavity 11 a. The corresponding collection cavity 11 b may further include a protective member 115, which is used to protect the isolation member 114, and which may form the collection cavity 11 b together with the isolation member 114, i.e., the wall of the collection cavity 11 b includes the protective member 115 and the isolation member 114.

[0079] 2 and 3, the housing 11 may include a sealed second cover, which is used to form the electrical cavity 11a, or an isolation member 114 may be provided inside the cover to isolate the electrical cavity 11a and the collection cavity 11b from the inside of the cover. The second cover may be implemented in various ways, for example, the second cover may include a third portion and a fourth portion, with an opening on one side of the fourth portion forming a semi-sealed structure, the isolation member 114 provided inside the fourth portion, and the third portion fitting over the opening of the fourth portion to form a more sealed second cover.

[0080] For convenience of explanation, the present application will be described mainly using the housing 11 shown in FIGS. 2 and 3 as an example, but the present application is not limited to this.

[0081] 4 shows a schematic exploded view of a battery 10 according to an embodiment of the present invention, which may correspond to the battery 10 shown in FIG. 2. As shown in FIG. 4, the battery 10 according to the present invention may include a housing 11, which includes a first cover 110, an isolation member 114, and a protective member 115, wherein the first cover 110 and the isolation member 114 form an electrical cavity 11a, and the isolation member 114 and the protective member 115 form a collecting cavity 11b. Specifically, as shown in FIG. 4, the first cover 110 further includes a first part 111 and a second part 112 having openings on opposite sides, wherein the first part 111 is used to cover the opening on one side of the second part 112 to form the first cover 110 having an open end, and the isolation part 114 is used to cover the opening on the opposite side of the second part 112 to form the electrical cavity 11a.

[0082] In this embodiment, the electrical cavity 11a has multiple walls, and the pressure release means 211 is provided on the first wall 21 of the battery cell 20, which may be any one of the walls facing the electrical cavity 11a of the battery cell 20. It should be understood that the shape of the battery cell 20 in this embodiment may be set according to actual applications. For example, although this embodiment mainly uses a rectangular parallelepiped battery cell 20 as an example, this embodiment is not limited thereto. For example, the battery cell 20 may be cylindrical or have other shapes. The first wall 21 may be any one of the walls of the battery cell 20.

[0083] In this embodiment, as shown in FIG. 4 , the electrical cavity 11 a includes a second wall 12, and the first wall 21 faces the second wall 12. That is, the pressure relief means 211 of the battery cell 20 faces the wall of the electrical cavity 11 a, not the other battery cells 20. This facilitates the provision of a relief structure in the wall of the electrical cavity 11 a, which is used to provide relief space for the pressure relief means 211 for modification. This improves the space utilization rate of the battery 10 and reduces the risk of a battery cell 20 experiencing thermal runaway causing thermal runaway in other battery cells 20, thereby improving the safety of the battery 10.

[0084] 4 illustrates an example in which the first wall 21 of the battery cell 20, where the pressure release means 211 is located, faces the isolation component 114, i.e., the isolation component 114 is used to form at least a part of the second wall 12. Specifically, as shown in FIG. 4, the pressure release means 211 is provided on the first wall 21 of the battery cell 20, which is the bottom wall of the battery cell 20, and the isolation component 114 is used on at least a part of the second wall 12 of the electrical cavity 11a, with the first wall 21 facing the isolation component 114. The isolation component 114 is used to isolate the electrical cavity 11a from the collection cavity 11b, and the isolation component 114 is also used to form at least a part of the second passage 132, so that the discharged matter that has passed through the pressure release means 211 passes through the isolation component 114 and is discharged from the electrical cavity 11a. For convenience of explanation, the present embodiment mainly takes the case where the second wall 12 is the isolation member 114 as an example, but the present embodiment is not limited thereto.

[0085] For example, the second wall 12 may be another wall of the electrical cavity 11a of the housing 11. For example, the second wall 12 may be any one wall of the second portion 112.

[0086] 4, the housing 11 may further include at least one beam 113, which is located between the plurality of battery cells 20 and serves to increase the structural strength of the housing 11. The beam 113 may also be used to divide the electrical cavity 11a into at least two sub-electrical cavities. For example, when the housing 11 in FIG. 4 is provided with one beam 113, the beam 113 can divide the electrical cavity 11a into two sub-electrical cavities, left and right, and the beam 113 is considered to be one wall of the electrical cavity 11a.

[0087] Therefore, the second wall 12 may be a beam 113, but the present embodiment is not limited thereto. Specifically, the beam 113 may be a hollow structure, which is used to form the collecting cavity 11b, i.e., the beam 113 is a wall shared by the electrical cavity 11a and the collecting cavity 11b. Specifically, when the isolation part 114 and the protective part 115 can be used to form part of the collection cavity 11b, and the hollow structure of the beam 113 can also be used to form part of the collection cavity 11b, i.e., when the hollow structure of the beam 113 is connected to the part of the collection cavity 11b formed by the isolation part 114 and the protective part 115, and when the pressure release means 211 is arranged facing the beam 113, i.e., when the beam 113 as the second wall 12 faces the first wall 21 on which the pressure release means 211 is located, the discharged matter discharged through the pressure release means 211 can pass through the beam 113 and enter the collection cavity 11b.

[0088] As will be understood, for convenience of explanation, the present embodiment will be mainly described using an example in which the isolation component 114 is the second wall 12, but the present embodiment is not limited to this, and the related explanations can also be applied to the case in which the beam 113 is the second wall 12 or the wall of another electrical cavity 11a is the second wall 12, and will not be repeated here for the sake of brevity.

[0089] 4 , the target structure includes the second wall 12, which means that the effluent discharged from the pressure release means 211 can pass through the second wall 12 and be discharged from the battery cell 20. By rationally setting the melting point of the second wall 12 in this way, the effluent discharged from the pressure release means 211 can quickly destroy the second wall 12 and be discharged from the battery cell 20, further improving the safety of the battery 10.

[0090] Optionally, at least a portion of the first passage 131 in the present embodiment may be formed between the first wall 21 and the second wall 12, and the first passage 131 may be realized in various ways. For example, as shown in FIGS. 2 to 4 , the battery 10 further includes a connection structure 14, which is formed between the first wall 21 and the second wall 12 and is used to form at least a portion of the first passage 131, and the target structure includes the connection structure 14. When at least a portion of the first passage 131 is formed by the connection structure 14, the connection structure 14 can achieve relative fixation between the first wall 21 and the second wall 12 and sealing between the first wall 21 and the second wall 12 when the battery cell 20 is not experiencing thermal runaway. Meanwhile, by rationally designing the specific shape and position of the connection structure 14, the position of the first passage 131 can be adjusted and directional discharge of waste matter passing through the first passage 131 can be achieved, thereby improving the safety of the battery 10. In addition, when the target structure includes a connecting structure 14, by rationally setting the melting point of the connecting structure 14, the discharged matter that has passed through the pressure release means 211 can be smoothly discharged through at least a portion of the first passage 131 formed by the connecting structure 14, thereby improving the safety of the battery 10.

[0091] In the present embodiment, the connecting structure 14 can realize at least a portion of the first passage 131 in various ways. FIG. 5 shows a schematic diagram of the local structure of one type of battery 10 in the present embodiment. For example, FIG. 5 is a schematic diagram of the local structure of the battery 10 shown in FIG. 4 , and FIG. 5 is a top view of the structure of the battery 10. For example, as shown in FIGS. 4 and 5 , the connecting structure 14 is provided with a flow path 141, and the first passage 131 includes the flow path 141. The effluent discharged through the pressure release means 211 can pass through the flow path 141 and be discharged into the electrical cavity 11a. In this way, by rationally configuring the position of the flow path 141, the effluent can be discharged in a directional manner, reducing the impact of the effluent on individual components in the electrical cavity 11a and further improving the safety of the battery 10.

[0092] Specifically, as shown in Figures 4 and 5, the flow path 141 of the present embodiment includes a through hole and / or a groove that penetrates the connection structure 14, making it easy to process and allowing waste to pass through quickly.

[0093] It should be understood that the dimensions of the flow passage 141 in the present embodiment may be set according to actual applications. For example, the radial dimension of the flow passage 141 may be less than 2 mm or 2 mm, and the radial direction of the flow passage 141 may be perpendicular to the flow direction of the effluent within the flow passage 141. This prevents the flow passage 141 from being too large, thereby preventing excessive effluent from flowing through the flow passage 141 and preventing the effluent particles from being too large, thereby filtering the effluent and reducing the impact of the effluent from a thermal runaway battery cell 10 on other battery cells 20 and minimizing thermal diffusion of the battery 10. Specifically, if the flow passage 141 is a through hole, the radial dimension of the flow passage 141 may be the maximum diameter of the hole of the flow passage 141. If the flow passage 141 is a groove, the radial dimension of the flow passage 141 may be the maximum depth or width of the groove, but the present embodiment is not limited thereto.

[0094] As can be understood, a filler may be provided in the flow path 141, and the connection structure 14 may include the filler, and the target structure may include the filler. By appropriately setting the melting point of the filler, the filler can be used to seal the flow path 141 when the pressure relief means 211 is not operating, and can be destroyed, for example, melted, when the pressure relief means 211 is operating, thereby allowing the flow in the flow path 141 to be conducted, improving the sealing of the electrical cavity 11a when the battery cell 20 is not experiencing thermal runaway, and preventing the battery cell 20 from being affected or destroyed. The material of the filler can be selected according to actual applications, and for example, the material of the filler may include polystyrene foam and / or plastic, but the embodiment of the present application is not limited thereto.

[0095] In the present embodiment, the flow path 141 is a groove provided in the connecting structure 14. As shown in FIGS. 4 to 5 , the connecting structure 14 may include a plurality of flow paths 141, and the plurality of flow paths 141 may be grooves facing the surface of the first wall 21 provided in the connecting structure 14, i.e., the opening of the groove faces the surface of the first wall 21, and / or may be grooves facing the surface of the second wall 12 provided in the connecting structure 14, i.e., the opening of the groove faces the second wall 12. For example, in FIGS. 4 and 5 , the flow path 141 is a groove facing the surface of the second wall 12 provided in the connecting structure 14, i.e., the opening of the groove faces the second wall 12.

[0096] In some embodiments, the connecting structure 14 is provided with a plurality of flow paths 141 extending along at least one direction, at least one of which is parallel to the first wall 21, i.e., the plurality of flow paths 141 extending along one or more directions on a surface with a larger area of ​​the connecting structure 14. By providing a plurality of flow paths 141, the discharge direction of the exhaust can be dispersed, and damage to components in that direction can be avoided when high-temperature exhaust is discharged in a single direction.

[0097] It is understood that the extending direction of the flow path 141 in the present embodiment may be set according to the actual application. For example, by rationally setting the extending direction of the flow path 141 according to the positional relationship between the electrode terminal 212 of the battery cell 20 and the pressure release means 211, it is possible to prevent the discharged matter from affecting the electrode terminal 212 and the bus component 30 connected to the electrode terminal 212.

[0098] 4 and 5, when the electrode terminal 212 and the pressure release means 211 are not located on the same wall and the wall on which the electrode terminal 212 is located does not intersect with the first wall 21, for example, when the wall on which the electrode terminal 212 is located is disposed opposite the first wall 21, the extending direction of the flow channel 141 is not limited. For example, the flow channel 141 may include one or more X-direction first flow channels 141a extending along a first direction X provided in the connection structure 14 and / or one or more Y-direction second flow channels 141b extending along a second direction Y provided in the connection structure 14. Alternatively, the flow channel 141 may further include flow channels in other directions provided in the connection structure 14, but this embodiment is not limited thereto. The first direction X and the second direction Y are perpendicular to each other. For example, the first direction X may be the thickness direction of the battery cell 20, as shown in FIGS. 4 and 5. Furthermore, the height direction Z of the battery cell 20 in this embodiment is perpendicular to the first direction X and the second direction Y.

[0099] In addition, for example, different from that shown in Figures 4 and 5, if the electrode terminal 212 is located on another wall, for example, the electrode terminal 212 is located on a wall intersecting the first wall 21, or the electrode terminal 212 is located on the first wall 21, by rationally setting the direction of the flow path 141, the influence of the discharged material on the electrode terminal 212 can be avoided, for example, short-circuiting between different bus components 30 connected to the electrode terminal 212 caused by metal scrap in the discharged material can be avoided, and the safety of the battery 10 can be further improved.

[0100] In the present embodiment, the connecting structure 14 may form at least a part of the first passage 131 in another manner. For example, the connecting structure 14 is used to be broken when the pressure release means 211 is activated to form a gap between the first wall 21 and the second wall 12, and the first passage 131 includes the gap. In this way, the target structure for forming the first passage 131 may include the connecting structure 14. By rationally selecting the material of the connecting structure 14, an appropriate melting point of the connecting structure 14 can be obtained. When the pressure release means 211 is activated, the connecting structure 14 is broken to form a gap and form the first passage. This eliminates the need for additional structures in the connecting structure 14, which is simpler and ensures the sealing of the battery cell 20 during normal use.

[0101] Specifically, in this embodiment, the destruction of the connecting structure 14 includes the destruction of at least a portion of the connecting structure 14. For example, when the pressure release means 211 operates, only the exterior of the connecting structure 14 may be destroyed, without destroying the exposed internal components of the connecting structure 14, or the internal structure of the connecting structure 14 may be destroyed. For example, if the connecting structure 14 has a multi-layer structure, some structural layers of the multi-layer structure may be destroyed, or the entire connecting structure 14 may be destroyed; this is not a limitation of this embodiment.

[0102] In this embodiment, as shown in Figures 4 and 5, the connecting structure 14 is provided with a relief opening 142 corresponding to the pressure release means 211, and the relief opening 142 is used to provide a deformation space when the pressure release means 211 operates, preventing the connecting structure 14 from blocking the pressure release means 211 and preventing the pressure release means 211 from not operating in a timely manner, and the relief opening 142 allows the discharged matter that has passed through the pressure release means 211 to be quickly discharged.

[0103] As can be understood, the relief opening 142 in the connection structure 14 can be used to provide a deformation space for the pressure relief means 211, so that the discharged matter passing through the pressure relief means 211 can be discharged through the relief opening 142 after being discharged from the battery cell 20. The relief opening 142 can be considered as at least a part of the first passage 131, and the discharged matter can be discharged to the electrical cavity 11a through the relief opening 142. The relief opening 142 can also be considered as at least a part of the second passage 132, and the discharged matter can be discharged again from the electrical cavity 11a through the relief opening 142, and the embodiment of the present application is not limited thereto.

[0104] 4 and 5, the relief opening 142 corresponds to at least one pressure release means 211. Optionally, considering that a plurality of battery cells 20 are usually arranged in a specific order within the battery 10, for convenience of processing, the relief opening 142 may simultaneously correspond to a plurality of pressure release means 211. For example, the relief openings 142 provided in the connection structure 14 may correspond to one row of battery cells 20, but the embodiment of the present application is not limited thereto.

[0105] As can be understood, the connection structure 14 of the present embodiment may be provided according to actual applications, and may include, for example, at least one of a bracket, a thermal conduction pad, a sealing pad, and a binder provided between the first wall 21 and the second wall 12. Specifically, the connection structure 14 may include a bracket for supporting and fixing the battery cells 20 provided between the first wall 21 and the second wall 12.

[0106] Optionally, the connection structure 14 may include a thermal conduction pad disposed between the first wall 21 and the second wall 12, thereby allowing the thermal conduction pad to dissipate heat from the battery cells 20 during use of the battery 10. For example, if the second wall 12 is a thermal management component, the thermal conduction pad can conduct heat from the battery cells 20 to the thermal management component to timely adjust the temperature of the battery cells 20 and ensure normal use of the battery cells 20. For example, as shown in FIGS. 4 and 5 , the connection structure 14 may include a thermal conduction pad, which is a portion that provides a plurality of Y-direction second flow paths 141b extending along the second direction Y in the figures.

[0107] Optionally, the connecting structure 14 may include a sealing pad provided between the first wall 21 and the second wall 12 to enhance sealing between the first wall 21 and the second wall 12. For example, as shown in FIGS. 4 and 5, the connecting structure 14 may include a sealing pad, and the sealing pad is a portion having a plurality of X-direction first flow channels 141a extending along the first direction X in the figures.

[0108] Optionally, the connection structure 14 may include a binder disposed between the first wall 21 and the second wall 12, which may be used for fastening, attaching and fastening the battery cells 20 to the second wall 12. For example, the binder included in the connection structure 14 may be used to fasten the battery cells 20 to the second wall 12.

[0109] As will be understood, the thermal conduction pad, sealing pad, and binder may be used alone or in combination. For example, as shown in Figures 4 and 5, a sealing pad may be provided on at least one edge of the thermal conduction pad, for example, sealing pads may be provided on two opposite edges of the thermal conduction pad, thereby dissipating heat and improving the sealing between the first wall 21 and the second wall 12. In addition, a binder may be used to fix the sealing pad and the thermal conduction pad to the battery cell 20 or the second wall 12, thereby improving the stability of the battery 10.

[0110] As will be appreciated, the materials of the thermal conduction pad, sealing pad, and binder in the present embodiment can all be selected according to the actual application. For example, the thermal conduction pad material can include thermally conductive silica gel. For example, the sealing pad material can include at least one of silicone rubber, polypropylene (PP), soluble polytetrafluoroethylene (PFA), and polyimide (PI). For example, the binder material can include at least one of epoxy structural adhesives, acrylate structural adhesives, polyimide structural adhesives, maleimide structural adhesives, urethane structural adhesives, and acrylic structural adhesives. Furthermore, for example, the binder layer material may include a polymer adhesive and a thermally conductive material, the polymer adhesive material may include at least one of epoxy resin, organic silica gel, and polyimide, and the thermally conductive material may include at least one of Al2O3, ZnO, BeO, AlN, Si3N4, BN, SiC, B4C, carbon nanotubes, and graphite nanosheets, but the embodiments of the present application are not limited thereto.

[0111] Optionally, the first passage 131 of the present embodiment can be realized in other ways. For example, a gap may be provided between the first wall 21 and the second wall 12 of the present embodiment, and the gap may be used to form at least a part of the first passage 131, thereby reducing the sealing requirements of the electrical cavity 11a, especially the second wall 12, and thereby reducing the difficulty and improving the processing efficiency of the battery 10.

[0112] As will be understood, the method of realizing at least a portion of the first passage 131 by the connecting structure 14 and the method of realizing at least a portion of the first passage 131 by the gap between the first wall 21 and the second wall 12 may be used alone or in combination with each other. For example, at least a portion of the first passage 131 may be jointly realized by the connecting structure 14 and the gap between the first wall 21 and the second wall 12, and the embodiments of the present application are not limited thereto.

[0113] The second passage 132 of the present embodiment will now be described by way of example with reference to the drawings.

[0114] 4 and 5, the second wall 12 is provided with a pressure release area 121 corresponding to the pressure release means 211, and the pressure release area 121 is used to form at least a part of the second passage 132. The second wall 12 is a wall of the electrical cavity 11a, and the effluent discharged through the pressure release means 211 passes through the pressure release area 121 of the second wall 12 to be discharged from the electrical cavity 11a. That is, the pressure release area 121 is at least a part of the second passage 132, thereby discharging the effluent, for example, into the collection cavity 11b, and preventing a large amount of effluent from entering the electrical cavity 11a and causing short circuits between the battery cells 20 or thermal diffusion, which would affect the safety of the battery 10.

[0115] As can be understood, each pressure release area 121 provided in the second wall 12 may correspond to one or more pressure release means 211. For example, as shown in Fig. 4, the second wall 12 is provided with a plurality of pressure release areas 121, and the plurality of pressure release areas 121 correspond one-to-one to the pressure release means 211 of the plurality of battery cells 20. Also, for example, the second wall 12 may be provided with one or more pressure release areas 121, and each pressure release area 121 may correspond to a plurality of pressure release means 211, and the embodiment of the present application is not limited thereto.

[0116] As will be appreciated, the pressure relief area 121 of the present embodiment can be realized in various ways. FIGS. 6 and 7 respectively show possible structural diagrams of the battery 10 of the present embodiment. As shown in FIGS. 6 and 7, the pressure relief area 121 is a through-hole penetrating the second wall 12, extending in the thickness direction of the second wall 12, and the second passage 132 includes the through-hole. When the pressure relief area 121 is a through-hole, it facilitates processing and allows the discharged effluent to be quickly released through the pressure relief means 211. However, when the pressure relief area 121 is a through-hole, the pressure relief means 211 is exposed, which makes the pressure relief means 211 more susceptible to external environmental influences during use of the battery 10, potentially leading to breakdown of the pressure relief means 211.

[0117] 6 and 7 , the battery 10 may further include a sealing structure 15, which is used to seal the through-hole and is broken when the pressure relief means 211 is activated to form at least a part of the second passage 132, and the target structure may include the sealing structure 15. When the pressure relief region 121 is a through-hole, the melting point of the sealing structure 15 may be appropriately set to maintain the sealing of the electrical cavity 11a and protect the pressure relief means 211 from the external environment during normal use of the battery cell 20. When the battery cell 20 experiences thermal runaway, the sealing structure 15 may be broken in a timely manner to expose the through-hole and form the second passage 132, allowing the waste from the battery cell 20 to pass through the through-hole and escape from the electrical cavity 11a, thereby avoiding thermal runaway and improving the safety of the battery 10.

[0118] Optionally, the position of the sealing structure 15 in the present embodiment may be set according to actual applications. For example, as shown in FIG. 6, the sealing structure 15 may be provided on the surface of the second wall 12 facing the first wall 21, and / or, for example, for processing convenience, the sealing structure 15 may be provided on the surface of the second wall 12 away from the first wall 21, as shown in FIG. 7. Also, when the sealing structure 15 is provided on the surface of the second wall 12 facing the first wall 21 as shown in FIG. 6, the sealing structure 15 is close to the pressure release means 211, allowing it to be quickly destroyed by the discharged material of the pressure release means 211, thereby avoiding the operation of the pressure release means 211 and allowing the discharged material to be discharged into the collection cavity 11b in a timely manner. When the sealing structure 15 is provided on the surface of the second wall 12 away from the first wall 21 as shown in FIG. 7, the distance between the pressure release means 211 and the sealing structure 15 provides a deformation space for the operation of the pressure release means 211, avoiding the impact on the pressure release means 211.

[0119] FIG. 8 shows another possible structural schematic diagram of the battery 10 according to the present invention. As shown in FIG. 8 , the pressure release area 121 is a weakened area of ​​the second wall 12, which is broken when the pressure release means 211 is activated to form at least a portion of the second passage 132. When the pressure release means 211 is activated, the weakened area is broken, allowing effluent from the battery cell 20 equipped with the pressure release means 211 to pass through the weakened area and exit the electrical cavity 11a, for example, into the collection cavity 11b. By using the pressure release area 121 as a weakened area, the second wall 12 remains sealed when the pressure release means 211 is not activated, for example, during normal use of the battery 10, effectively protecting the pressure release means 211 from failure due to external force. When the battery cell 20 experiences thermal runaway, the weakened area is broken in a timely manner to allow effluent to be discharged from the electrical cavity 11a, thereby avoiding thermal runaway and improving the safety of the battery 10.

[0120] As can be seen, when the target structure includes a weakened region, by reasonably setting the melting point of the weakened region, the weakened region has sufficient strength during normal use of the battery cell 20, maintains the sealing of the electrical cavity 11a, and protects the pressure relief means 211 from the influence of the external environment; and when the battery cell 20 experiences thermal runaway, the weakened region can be broken in a timely manner, for example, melted in a timely manner to form the second passage 132, allowing the discharged matter of the battery cell 20 to pass through the broken pressure relief region 121 and be discharged from the electrical cavity 11a, thereby avoiding thermal runaway and improving the safety of the battery 10.

[0121] The weakened region of the present embodiment may be provided in a form that is easily broken by the effluent, and the present embodiment is not limited thereto. For example, the thickness of the weakened region may be thinner than the thickness of the region surrounding the weakened region of the second wall 12. By making the thickness of the weakened region thinner, its strength is reduced, and the effluent can melt and break the weakened region quickly, allowing the effluent to be discharged in a timely manner.

[0122] 2, the second wall 12 is provided with a groove corresponding to the pressure release means 211, with the opening facing the pressure release means 211, and the weakened area is the bottom wall of the groove. In this way, the opening of the groove corresponds to the pressure release means 211, and the inside of the groove can provide a deformation space for the pressure release means 211, and for convenience in processing, the bottom wall is made the weakened area.

[0123] As can be seen, the first passage 131 in this embodiment can discharge the effluent discharged through the pressure release means 211 to the electrical cavity 11a, and furthermore, a first balancing valve is provided on the wall of the casing 11 of the battery 10, which is used to discharge the effluent that has passed through the first passage 131 from the casing 11, thereby avoiding heat diffusion caused by the accumulation of effluent in the casing 11 and improving the safety of the battery 10. Specifically, in order to timely discharge the effluent from the electrical cavity 11a, the first balancing valve may be provided on the wall forming the electrical cavity 11a.

[0124] Similarly, the second passage 132 can discharge the effluent discharged from the electrical cavity 11a through the pressure release means 211. For example, if the collection cavity 11b is not provided, the effluent may be discharged directly from the housing 11. Alternatively, for example, by providing the collection cavity 11b, the effluent is discharged into the collection cavity 11b. However, since the space of the collection cavity 11b is limited, a second balancing valve may be provided in the wall of the housing 11 to discharge the effluent discharged through the second passage 132 from the housing 11. This allows the effluent to be discharged from the battery 10 through the collection cavity 11b, avoiding thermal diffusion or explosion due to the accumulation of the effluent in the collection cavity 11b of the housing 11 and improving the safety of the battery 10. Specifically, in order to timely discharge the effluent from the collection cavity 11b, the second balancing valve may be provided in the wall forming the collection cavity 11b.

[0125] The battery 10 of this embodiment includes a housing 11, a battery cell 20, and a discharge passage 13. The battery cell 20 is accommodated in an electrical cavity 11a of the housing 11. A pressure relief means 211 is provided on a first wall 21 of the battery cell 20. The discharge passage 13 connects to the interior of the battery cell 20 via the pressure relief means 211 when the pressure relief means 211 is activated, allowing waste from the battery cell 20 to be discharged via the pressure relief means 211 and the discharge passage 13. Furthermore, the battery 10 satisfies 0.05wh / (kg·°C)≦a / b≦25wh / (kg·°C), where a is the weight energy density of the battery cell 20 and b is the melting point of the target structure for forming the discharge passage 13. Rational setting of the a / b value allows waste from the battery cell 20 to be discharged in a timely manner, improving the safety of the battery 10.

[0126] Although the present application has been described with reference to preferred embodiments, various modifications may be made and elements may be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural contradiction, any of the various technical features described in each embodiment may be combined in any manner. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims.

Claims

1. a housing (11) containing an electrical cavity (11a); a battery cell (20) accommodated in the electrical cavity (11a), the battery cell (20) having a pressure release means (211) on a first wall (21) of the battery cell (20); a discharge passage (13) arranged to communicate with the interior of the battery cell (20) through the pressure release means (211) when the pressure release means (211) is activated; Including, wherein the battery satisfies 0.05Wh / (kg ° C)≦a / b≦25Wh / (kg ° C), where a is the weight energy density of the battery cell (20) and b is the melting point of the target structure for forming the discharge passage (13); The electrical cavity (11a) includes a second wall (12), and the first wall (21) faces the second wall (12); the discharge passage (13) includes a first passage (131), which is used to discharge the discharged matter discharged from the pressure release means (211) to the electrical cavity (11a); The battery further includes a connection structure (14), the connection structure (14) being provided between the first wall (21) and the second wall (12), the connection structure (14) being used to form at least a portion of the first passage (131), and the target structure including the connection structure (14).

2. 2. The battery according to claim 1, wherein the battery satisfies 0.06 wh / (kg·° C.)≦a / b≦15 wh / (kg·° C.).

3. 2. The battery according to claim 1, wherein the weight energy density a value of the battery cell (20) is in the range of 100 Wh / kg to 3505 Wh / kg.

4. 4. The battery according to claim 1, wherein the melting point b value of the target structure is in the range of 100°C to 2000°C.

5. 2. The battery of claim 1, wherein the target structure includes the second wall (12).

6. The battery according to claim 1, wherein the connecting structure (14) is provided with a flow path (141), and the first passage (131) includes the flow path (141).

7. 2. The battery of claim 1, wherein the connecting structure (14) is used to be broken when the pressure release means (211) is activated to form a gap between the first wall (21) and the second wall (12), and the first passage (131) includes the gap.

8. 2. The battery according to claim 1, wherein the connecting structure (14) is provided with a relief opening (142) corresponding to the pressure release means (211), and the relief opening (142) is used to provide a deformation space when the pressure release means (211) operates.

9. 2. The battery of claim 1, wherein the exhaust passage (13) includes a second passage (132), the second passage (132) being used to exhaust from the electrical cavity (11a) exhausted from the pressure release means (211).

10. 10. The battery of claim 9, wherein the second wall (12) is provided with a pressure release area (121) corresponding to the pressure release means (211), and the pressure release area (121) is used to form at least a part of the second passage (132).

11. The battery of claim 10, characterized in that the pressure release area (121) is a through hole penetrating the second wall (12), the penetrating direction is in the thickness direction of the second wall (12), and the second passage (132) includes the through hole.

12. The battery of claim 11, further comprising a sealing structure (15), the sealing structure (15) being used to seal the through-hole, the sealing structure (15) being broken when the pressure release means (211) is activated so that the through-hole forms at least a part of the second passage (132), and the target structure comprising the sealing structure (15).

13. the sealing structure (15) is provided on the surface of the second wall (12) facing the first wall (21), and / or 13. The battery according to claim 12, wherein the sealing structure (15) is provided on a surface of the second wall (12) remote from the first wall (21).

14. 11. The battery of claim 10, wherein the pressure release area (121) is a weakened area of ​​the second wall (12), which is adapted to be broken when the pressure release means (211) is activated to form at least a portion of the second passage (132).

15. The battery of claim 14 , wherein the target structure comprises the weakened area.

16. 15. The battery according to claim 14, characterized in that the thickness of the weakened area is less than the thickness of the area of ​​the second wall (12) located around the weakened area.

17. 15. The battery of claim 14, wherein the second wall (12) is provided with a groove corresponding to the pressure release means (211) and with an opening facing the pressure release means (211), and the weakened area is the bottom wall of the groove.

18. The housing (11) 10. The battery of claim 9, further comprising a collection cavity (11b) for collecting effluent discharged through said second passage (132) when said pressure relief means (211) is operated.

19. 19. The battery of claim 18, further comprising an isolation element (114) for isolating the electrical cavity (11a) and the collecting cavity (11b).

20. 20. The battery of claim 19, wherein the isolation piece (114) is used to define at least a portion of the second passageway (132).

21. An electrical device comprising a battery according to any one of claims 1 to 3, characterized in that said battery is used to provide electrical energy to said electrical device.

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