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 progress of battery technology, various new energy industries using batteries as energy storage devices are developing rapidly. In addition to improving the performance of batteries, the development of battery technology also requires safety issues. If the safety issues of a battery cannot be ensured, the battery cannot be used. Therefore, how to improve the safety of a battery is a technical problem that must be solved as soon as possible in battery technology. Summary of the Invention

[0003] The present embodiments provide batteries and electrical devices that can improve the safety performance of the batteries.

[0004] In a first aspect, there is provided a battery including a housing including an electrical cavity, a battery cell accommodated in the electrical cavity, the battery cell having a first wall provided with a pressure release means, and a discharge passage arranged to communicate with the inside of the battery cell through the pressure release means when the pressure release means is operated, wherein 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 discharge passage.

[0005] Therefore, in the battery of the embodiment of the present application, 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 is set relatively high and the weight energy density a of the battery cell is relatively small. Correspondingly, the temperature of the discharged material discharged when thermal runaway occurs in the battery cell will be low, and the temperature resistance of the target structure will exceed the temperature of the discharged material, so that the discharged material will be restricted to the periphery of the pressure relief means and may not be 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 will cause thermal diffusion between the battery cells, and there is a risk of the battery exploding, so it is not preferable to make the a / b value small.

[0007] Conversely, it is not preferable to increase the a / b value. Due to the structural limitations of the battery cell itself, the weight energy density a of the battery cell has an upper limit, and similarly, the melting point b of the target structure for forming the exhaust passage also has a lower limit. Therefore, if the a / b value is too large, and the a value is constant, the b value becomes too small, that is, the melting point b of the target structure for forming the exhaust passage becomes too low, which leads to 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, which may further reduce the sealing performance of the exhaust passage, and if the exhaust passage is destroyed and the battery cell goes into thermal runaway, it may affect the exhaust path of the exhaust and reduce the safety of the battery.

[0008] In some embodiments, the battery satisfies 0.06wh / (kg·°C)≦a / b≦15wh / (kg·°C), so that the gravimetric energy density a of the battery cell is more appropriate and the melting point b of the target structure is not too large or too small, thereby 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 is in the range of 100Wh / kg to 3505Wh / kg. If the weight energy density a of the battery cell is too small, the battery 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 difficult to realize.

[0010] In some embodiments, the melting point b of the target structure is in the range of 100° C. to 2000° C. If the melting point b of the target structure is too small, the selectable materials are limited, and the strength of the target structure is insufficient, 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 of the battery cell cannot be discharged through the exhaust passage in a timely manner, which may further cause thermal diffusion between the battery cells, affecting the safety of the battery.

[0011] In some embodiments, the electrical cavity includes a second wall, and the first wall faces the second wall, i.e., the pressure relief means of the battery cell faces the wall of the electrical cavity, not the other battery cells, which makes it easy to provide an escape structure on the wall of the electrical cavity to provide an escape space for the deformation of the pressure relief means, improves the space utilization rate of the battery, and also reduces the risk that a battery cell that has experienced thermal runaway will cause thermal runaway in other battery cells, thereby improving the safety of the battery.

[0012] In some embodiments, the target structure includes the second wall, i.e., the effluent discharged from the pressure release means can pass through the second wall and be discharged from the battery cell. In this way, by rationally 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, which further improves the safety of the battery.

[0013] In some embodiments, the exhaust passage includes a first passage, which is used to exhaust exhausted from the pressure relief means to the electrical cavity. When the battery includes a first passage, at least a portion of the exhaust exhausted through the pressure relief means of the battery cell passes through the first passage and is exhausted 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 connection structure, the connection structure being disposed between the first wall and the second wall, the connection structure being used to form at least a portion of the first passage, and the target structure including the connection structure. The connection structure realizes at least a portion of the first passage, and when no thermal runaway occurs in the battery cell, the connection structure realizes the relative fixation between the first wall and the second wall and the sealing between the first wall and the second wall, while the specific form and position of the connection structure can be reasonably set to adjust the position of the first passage, and further realize the directional discharge of the effluent that has passed through the first passage, thereby improving the safety of the battery. In addition, when the target structure includes a connection structure, the melting point of the connection structure can be reasonably set to allow the effluent that has passed through the pressure release means to be smoothly discharged through at least a portion of the first passage formed by the connection structure, thereby improving the safety of the battery.

[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 be discharged into the electrical cavity through the flow path, and the position of the flow path can be rationally set to realize directional discharge of the effluent, which reduces the impact of the effluent on individual components in the electrical cavity and further improves the safety of the battery.

[0016] In some embodiments, the connection structure is used to break and form a gap between the first wall and the second wall when the pressure release means is operated, 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, a suitable melting point of the connection structure can be obtained, and the connection structure is broken and further forms a gap when the pressure release means is operated to form the first passage, and the connection structure does not need to have an additional structure, is more simple, and can also ensure the sealing property during normal use of the battery cell.

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

[0018] In some embodiments, the vent passage includes a second passage, the second passage being used to vent effluent vented from 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 to a collection cavity to prevent a large amount of the effluent from entering the electrical cavity, leading to short circuit or thermal diffusion between battery cells, 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 direction is the thickness direction of the second wall, and the second passage includes the through hole. When the pressure relief area is a through hole, the processing is easy and the discharged matter 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, and the pressure relief means is easily affected by the external environment during the use of the battery, which may even lead to the breakdown of the pressure relief means.

[0021] In some embodiments, the battery further includes a sealing structure, the sealing structure is used to seal the through-hole, the sealing structure is used to break when the pressure release means operates to form at least a part of the second passage through the through-hole, and the target structure includes the sealing structure. When the pressure release area is a through-hole, the melting point of the sealing structure can be reasonably set to maintain the sealing of the electrical cavity during normal use of the battery cell and protect the pressure release means from the influence of the external environment, while 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 passage, so that the exhaust of the battery cell can pass through the through-hole to exhaust from the electrical cavity, 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 a 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 the influence on the operation of the pressure relief means and allowing the discharge to be discharged into the collection cavity in a timely manner. When the sealing structure is provided on a 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 can avoid the influence on the pressure relief means.

[0023] In some embodiments, the pressure relief area is a weakened area of ​​the second wall, which is broken to form at least a part of the second passage when the pressure relief means is operated. When the pressure relief means is operated, the weakened area is broken so that the effluent from the battery cell provided with the pressure relief means can pass through the weakened area to be discharged from the electrical cavity, for example, through the weakened area to enter the collection cavity. By providing the pressure relief area as a weakened area, when the pressure relief means is not operated, for example, during the normal use of the battery, the second wall can be sealed to effectively protect the pressure relief means from being broken and damaged by external forces, and when thermal runaway occurs in the battery cell, the weakened area can be broken in a timely manner to discharge the effluent from the electrical cavity, to avoid thermal runaway, and to improve the safety of the battery.

[0024] In some embodiments, when the target structure includes the weakened area, the melting point of the weakened area can be reasonably set so that the weakened area has sufficient strength during the 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 area can be destroyed 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 destroyed pressure relief area 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 area is less than the thickness of the area of ​​the second wall surrounding the weakened area, and by reducing the thickness of the weakened area, its strength is reduced, allowing the effluent to quickly destroy the weakened area by melting and breaking, and to evacuate the effluent in a timely manner.

[0026] In some embodiments, the second wall is provided with a groove corresponding to the pressure release means and 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, 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 operated. The collection cavity can collect and / or process the effluent in a centralized manner and discharge the effluent to the outside of the battery. For example, the collection cavity may include a liquid, such as a cooling medium, for further lowering the temperature of the effluent placed 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 and the collection cavity, the isolation member being employed to isolate the electrical cavity and 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 component is used to form at least a portion of the second passageway, such that effluent passing through the pressure relief means can pass through the isolation component 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 description of the drawings]

[0032] [Figure 1] 1 is a structural schematic diagram of a vehicle disclosed in an embodiment of the present application; [Diagram 2] FIG. 1 is a structural schematic diagram of a type of battery disclosed in an embodiment of the present application. [Diagram 3] FIG. 2 is a structural schematic diagram of another battery disclosed in an embodiment of the present application. [Figure 4] FIG. 2 is an exploded structural schematic diagram of a battery disclosed in an embodiment of the present application. [Diagram 5] FIG. 2 is a schematic diagram showing 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 PREFERRED EMBODIMENTS

[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 illustratively explain 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 the directions or positional relationships of terms such as "upper", "lower", "left", "right", "inner", "outer", etc. are intended only to facilitate and simplify the description of this application, and do not indicate or imply that the devices or elements shown have a particular orientation, are configured, or must operate in a particular direction, and should not be understood as limiting this application. In addition, terms such as "first", "second", "third", etc. are merely for descriptive purposes, and should not be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but has a margin of error. "Parallel" is not strictly parallel, but has a margin of error.

[0036] Any directional terms used in the following description are 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 be fixedly connected, detachably connected, or integrated, and may be directly connected or indirectly connected via an intermediate medium. Those skilled in the art can understand the specific meaning of these terms in the present application according to the specific situation.

[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, and the overall thickness, length, width, and other dimensions of the integrated device are merely illustrative and do not limit the present application.

[0038] In the present application, the battery cell may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, or a magnesium ion battery, etc., and there is no limitation thereto in the embodiments of the present application. The battery cell may be a cylinder, a flat body, a rectangular parallelepiped, or other shape, and there is no limitation thereto in the embodiments of the present application. Battery cells are generally broadly divided into three types, namely, a prismatic battery cell, a rectangular battery cell, and a soft pouch battery cell, depending on the packaging method, and there is no limitation thereto in the embodiments of the present application.

[0039] The battery referred to in the embodiments of the present application means a single physical module including one or more battery cells to provide higher voltage and / or capacity. For example, the battery referred to in the present application may include a battery module or a battery pack. The battery usually 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] The 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 is mainly operated by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer, the positive electrode active material layer is applied to the surface of the positive electrode collector, the current collector on which the positive electrode active material layer is not applied protrudes from the current collector on which the positive electrode active material layer is applied, and the current collector on which the positive electrode active material layer is not applied is a positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganate, 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, the current collector on which the negative electrode active material layer is not applied protrudes from the current collector on which the negative electrode active material layer is applied, and the current collector on which the negative electrode active material layer is not applied is 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. The positive electrode tab is formed by stacking a plurality of pieces, and the negative electrode tab is formed by stacking a plurality of pieces, so that a large current can pass without melting. The material of the separator may be polypropylene (PP) or polyethylene (PE), or the like. In addition, the electrode assembly may be a wound type structure or a stacked type structure, and the embodiment of the present application is not limited thereto.

[0041] The development of battery technology requires simultaneous consideration of various design factors, such as performance parameters such as energy density, cycle life, discharge capacity, charge / discharge rate, and the like, and furthermore, the safety of the battery must be considered. For batteries, safety hazards are mainly caused by the charging and discharging process, and in order to improve the safety performance of the battery, it is common to provide a pressure relief means for the battery cell. The pressure relief means is an element or component that operates to release the internal pressure or temperature when the internal pressure or temperature of the battery cell reaches a certain threshold. The certain threshold can be adjusted according to different design needs. For example, the certain threshold may be determined by one or more materials of the positive electrode sheet, the negative electrode sheet, the electrolyte, and the separator in the battery cell. The pressure relief means may be a pressure-sensitive or temperature-sensitive element or structure, i.e., when the internal pressure or temperature of the battery cell reaches a certain threshold, the pressure relief means operates to form a passage for releasing the internal pressure or temperature.

[0042] In the conventional design proposals for pressure relief means, attention is mainly paid to 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 the discharge path for the high temperature and high pressure discharged material after it is discharged from the battery cell, so as to ensure that the discharged material is discharged in a timely and smooth manner to avoid causing further safety problems to the battery, is one of the problems that needs to be solved 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 discharge passage, the battery cell is accommodated in an electrical cavity of the housing, a pressure relief means is provided on a first wall of the battery cell, and the discharge passage is connected to the inside of the battery cell through the pressure relief means when the pressure relief means operates, so that the discharged matter inside the battery cell can be discharged through the pressure relief means and the discharge 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 a target structure for forming the discharge passage. If the a / b value is too small, the melting point of the target structure is set relatively high and the weight energy density of the battery cell is relatively small. Correspondingly, the temperature of the exhaust material discharged when thermal runaway occurs in the battery cell will be low, and the temperature resistance of the target structure will exceed the temperature of the exhaust material, which may result in the exhaust material being restricted to the periphery of the pressure relief means and unable to pass through the exhaust passage for discharge. If the exhaust material 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, and there is a risk of the battery exploding, so it is not preferable to make the a / b value small.

[0044] Conversely, it is not preferable to make the a / b value large. Due to the structural limitations of the battery cell itself, there is an upper limit to the weight energy density of the battery cell, and similarly, there is a lower limit to the melting point of the target structure forming the exhaust passage. Therefore, if the a / b value is too large, and the a value is constant, the b value becomes too small, that is, the melting point b of the target structure forming the exhaust passage becomes too low, which leads to 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, which may further reduce the sealing property of the exhaust passage, and if the exhaust passage is destroyed and the battery cell goes into thermal runaway, it may affect the exhaust path of the exhaust, which may reduce the safety of the battery. Therefore, it is not preferable to make the a / b value in the present embodiment 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, a ship, 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-extender electric vehicle, etc. The spacecraft may include an airplane, a rocket, a space shuttle, a spaceship, etc. The electric toy may include a stationary or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, or an electric plane toy. The electric tool may include, 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 plane, or other metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools. In the embodiments of the present application, there is no particular limitation 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, as shown in FIG. 1, a structural schematic diagram of a vehicle 1 according to an embodiment of the present application, the vehicle 1 may be a gasoline vehicle, a natural gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range extender electric vehicle, etc. A motor 40, a controller 30, and a battery 10 may be provided inside the vehicle 1. The controller 30 is used to control the battery 10 to supply power to the motor 40. For example, the battery 10 may be provided at the bottom, head, or rear of the vehicle 1. The battery 10 can be applied to power the vehicle 1, for example, the battery 10 can be used as an operating power source for the vehicle 1, and can be applied to the electrical system of the vehicle 1, for example, used to control the working power when the vehicle 1 is started, navigated, or driven. In another embodiment of the present application, the battery 10 not only functions as an operating power source for the vehicle 1, but also functions as a driving power source for the vehicle 1, and can provide driving force to the vehicle 1 as a replacement or partial replacement for gasoline or natural gas.

[0049] In order to meet various power usage needs, a battery may include multiple battery cells, among which multiple battery cells may be connected in series, parallel, or series-parallel, where series-parallel connection means a mixture 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 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] Fig. 2 shows a schematic diagram of the structure of a battery 10 in an embodiment of the present application. As shown in Fig. 2, the battery 10 may include a housing 11 including an electric cavity 11a, a battery cell 20 accommodated in the electric cavity 11a, the battery cell 20 having a pressure relief means 211 provided on a first wall 21 of the battery cell 20, and a discharge passage 13 arranged to communicate with the inside of the battery cell 20 through the pressure relief means 211 when the pressure relief means 211 operates, where 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 a target structure for forming the discharge passage 13.

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

[0052] As can be understood, the pressure release means 211 of the present embodiment is used to operate and release the internal pressure or temperature of the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold value. The value of the threshold value may vary according to design needs. The threshold value 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" referred to in this application 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. The operation by the pressure relief means 211 may include, but is not limited to, cases where at least a part of the pressure relief means 211 is broken, 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 operated location as discharge. In this way, by releasing the pressure or temperature of the battery cell 20 in a situation where the pressure or temperature is controllable, it is possible to avoid a potentially more serious accident.

[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 embodiment of the present application is provided in the first wall 21 of the battery cell 20, and the pressure release means 211 may be a part of the first wall 21, or may be a separate structure from the first wall 21 and may be 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 cut in the first wall 21, and the thickness of the first wall 21 corresponding to the cut is smaller than the thickness of other areas of the pressure release means 211 excluding the cut. The cut is the thinnest part of the pressure release means 211. When too much gas is generated by the battery cell 20, causing the internal pressure to rise and reach a threshold value, or when the heat from the reaction inside the battery cell 20 causes the internal temperature of the battery cell 20 to rise and reach 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] Also, for example, the pressure release means 211 may be a structure separate 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 destroyed to form an opening or passage for releasing the internal pressure or temperature.

[0057] In the present embodiment, the battery 10 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 exhaust passage. By rationally setting the a / b value, the 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 is set relatively high, and the weight energy density a of the battery cell 20 is relatively small. Correspondingly, the temperature of the discharged material discharged when the battery cell 20 experiences thermal runaway will be low, and the temperature resistance of the target structure will exceed the temperature of the discharged material, so that the discharged material will be restricted to the periphery of the pressure relief means and may not be able to pass through the discharge passage 13 for discharge. If the discharged material cannot be discharged in a timely manner away from the area where the pressure relief means 211 is located, it will cause thermal diffusion between the battery cells 20, and there is a risk of the battery 10 exploding, so it is not preferable to make the a / b value small.

[0059] Conversely, it is not preferable to increase the a / b value. Due to the structural limitations of the battery cell 20 itself, the weight energy density a of the battery cell 20 has an upper limit, and similarly, the melting point b of the target structure forming the exhaust passage also has a lower limit. Therefore, if the a / b value is too large, and the a value is constant, the b value becomes too small, that is, the melting point b of the target structure forming the exhaust passage 13 becomes too low, which leads to 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, reducing the sealing stability of the exhaust passage 13, and furthermore, if the exhaust passage 13 is destroyed and the battery cell 20 goes into thermal runaway, it may affect the exhaust path of the exhaust, thereby 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), 21wh / (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), 32 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, when the battery 10 satisfies 0.06wh / (kg·°C)≦a / b≦15wh / (kg·°C), the weight energy density a of the battery cell 20 is appropriate and the melting point b of the target structure is not too large or too small, 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 weight energy density a of the battery cell 20 is 100Wh / kg to 3505Wh / 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 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 100wh / kg, 120wh / kg, 150wh / kg, 200wh / kg, 250wh / kg, 300wh / kg, 350wh / kg, 400wh / kg, 420wh / kg, 450wh / kg, 500wh / kg, 800wh / kg, 1000wh / kg, 1500wh / kg, 2000wh / kg, 2500wh / kg, or 3505wh / 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 100wh / kg to 1500wh / 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, while the strength of the target structure may be insufficient, which may further lead to a decrease in the strength of the exhaust passage and poor sealing. Conversely, if the melting point b of the target structure is too high, the exhaust material of the battery cell 20 may not be able to be exhausted 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 usually set to 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. In addition, for example, taking into consideration the temperature of the discharged material discharged 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 only, the discharge passage 13 and target structure according to an embodiment of the present invention with reference to the drawings.

[0065] In the present embodiment, as shown in FIG. 2, the electrical cavity 11a according to the present embodiment is further used to accommodate other components, for example, the bus component 30, that is, the electrical cavity 11a provides a mounting space for the battery cell 20 and the bus component 30. The bus component 30 is used to realize an electrical connection between the multiple battery cells 20, for example, a series connection, a parallel connection, or a series-parallel connection. The bus component 30 can realize an electrical connection between the battery cells 20 by connecting to the electrode terminals 212 of the battery cells 20. 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 in 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 in 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, each electrode terminal 212 in the embodiment of the present application may be provided on any one of the walls, and the 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, in the case where 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 facing the first wall 21, so that when the pressure release means 211 of the first wall 21 operates, the two electrode terminals 212 are not affected or only slightly affected, and short-circuiting between the battery cells 20 can be avoided. Alternatively, the two electrode terminals 212 may be located on other walls, and the embodiment of the present application is not limited thereto.

[0068] Similarly, for example, in a 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 embodiment of the present application. As shown in FIG. 3, the two electrode terminals 212 of the battery cell 20 may be located on two walls that are provided so as to face each other, respectively. Alternatively, the two electrode terminals 212 of the battery cell 20 may be located on two intersecting walls, and the embodiment of the present application is not limited to this.

[0069] As can be understood, as shown in Figures 2 and 3, the exhaust passage 13 in the embodiment of the present application may include a first passage 131 and / or a second passage 132, in which 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] When the battery 10 includes the first passage 131 but does not include the second passage 132, the waste discharged through the pressure release means 211 of the battery cell 20 passes through the first passage 131 and is discharged to the electrical cavity 11a in which the battery cell 20 is located, eliminating the need to provide another passage for discharging the waste from the electrical cavity 11a, and making the structure of the housing 11 simple and easy to implement. However, since the waste discharged from the battery cell 20 has high temperature and high pressure characteristics and may contain a large amount of metal particles, discharging the entire waste directly into the electrical cavity 11a is likely to cause a short circuit between the battery cells 20 and thermal diffusion, and may even lead to an explosion of the battery 10, 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, the exhaust discharged through the pressure release means 211 of the battery cell 20 must pass through the second passage 132 to be discharged from the electrical cavity 11b, and the exhaust does not affect the battery cell 20 in the electrical cavity 11b at all, effectively avoiding thermal diffusion and short circuit of the battery cell 20 caused by the exhaust, and further improving the safety of the battery 10. In addition, the second passage 132 allows the exhaust of the battery cell 20 to be collected in a concentrated manner, and prevents the exhaust from affecting other components.

[0072] Alternatively, the battery 10 may include 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 discharge generated inside the battery cell 20 is discharged toward the arrangement direction of the pressure release means 211 of the battery cell 20. Such discharge is usually very powerful and destructive. If only one passage is provided, it may break through the structure of the passage or one or more structures around the passage, causing further safety problems. Therefore, it is conceivable to divide the discharged discharged through the pressure release means 211 into two passages and discharge them jointly, which not only increases the discharge speed to reduce the risk of explosion of the battery 10, but also achieves directional and dispersed discharge to avoid the impact of the discharged discharge on other components, thereby improving the safety and stability of the battery 10.

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

[0074] Specifically, as shown in FIG. 2 and FIG. 3, the housing 11 of the embodiment of the present application may further include a collection cavity 11b used to collect and / or process the effluent discharged through the pressure release means 211 when the pressure release means 211 is operated, for example, to collect the effluent discharged through the second passage 132 when the pressure release means 211 is operated, and to discharge the effluent to the outside of the battery 10. The collection cavity 11b is used to collect the effluent, and may be sealed or not sealed. 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, for further lowering the temperature of the effluent entering the collection cavity 11b, or a component for containing the liquid may be provided. Furthermore, 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 the present embodiment further includes an isolation part 114 for isolating the electrical cavity 11a and the collecting cavity 11b. Here, "isolation" means to be separated, and does not have to be sealed. Specifically, the isolation part 114 is used to isolate the electrical cavity 11a and the collecting cavity 11b, that is, the electrical cavity 11a for accommodating the battery cell 20 and the collecting cavity 11b for collecting waste are isolated from each other.

[0076] In the present embodiment, the isolation component 114 may include a wall shared by the electrical cavity 11a and the collection cavity 11b. 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 11a and the collection cavity 11b, thus making the distance between the electrical cavity 11a and the collection cavity 11b as short as possible, thus saving space and improving the space utilization rate of the housing 11.

[0077] Optionally, the isolation component 114 in the embodiment of the present application may be a thermal management component, and the thermal management component is used to adjust the temperature of the battery cell 20. Specifically, the isolation component 114 is used to accommodate a fluid for adjusting the temperature of the battery cell 20. When the temperature of the battery cell 20 is to be lowered, the isolation component 114 may accommodate a cooling medium to adjust the temperature of the battery cell 20, in which case the isolation component 114 may also be called a cooling component, a cooling system, or a cooling plate. The isolation component 114 may also be used for heating, and there is no limitation thereto in the embodiment of the present application. Optionally, in order to obtain a better temperature adjustment effect, the fluid in the isolation component 114 may flow circulatoryly.

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

[0079] 2 and 3, the housing 11 may include a second cover that is hermetically sealed, and the second cover 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 from the inside of the cover and further isolate the collecting cavity 11b. The second cover may be realized in various ways, for example, the second cover may include a third part and a fourth part, and one side of the fourth part has an opening to form a semi-sealed structure, the isolation member 114 is provided inside the fourth part, and the third part is fitted to the opening of the fourth part to form a second cover that is hermetically sealed.

[0080] For convenience of explanation, the present application will be explained mainly using the housing 11 shown in FIG. 2 and FIG. 3 as an example, but the embodiment of the present application is not limited thereto.

[0081] Fig. 4 shows an exploded structural schematic diagram of a battery 10 according to an embodiment of the present application, and for example, Fig. 4 may correspond to the battery 10 shown in Fig. 2. As shown in Fig. 4, the battery 10 according to the embodiment of the present application may include a housing 11, which includes a first cover 110, an isolation part 114, and a protective part 115, in which the first cover 110 and the isolation part 114 are used to form an electrical cavity 11a, and the isolation part 114 and the protective part 115 are used to 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 an opening on each of opposing sides, in which the first part 111 is used to cover an 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 an opening on the opposite side of the second part 112 to form the electrical cavity 11a.

[0082] In the present 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 is understood that the shape of the battery cell 20 in the present embodiment may be set according to the actual application. For example, the present application mainly takes the rectangular parallelepiped battery cell 20 as an example, but the present embodiment is not limited thereto, for example, the battery cell 20 may be a cylinder or other shapes. The first wall 21 may be any one of the walls of the battery cell 20.

[0083] In the present embodiment, as shown in FIG. 4 , the electrical cavity 11a includes the second wall 12, and the first wall 21 faces the second wall 12, i.e., the pressure relief means 211 of the battery cell 20 faces the wall of the electrical cavity 11a, not the other battery cells 20. This makes it easy to provide an escape structure in the wall of the electrical cavity 11a, which is used to provide an escape space for the pressure relief means 211 for modification, thereby improving the space utilization rate of the battery 10 and reducing the risk of a battery cell 20 causing thermal runaway in other battery cells 20, thereby improving the safety of the battery 10.

[0084] For example, FIG. 4 shows an example in which the first wall 21 of the battery cell 20 where the pressure release means 211 is located faces the isolation part 114, that is, the isolation part 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, the first wall 21 is the bottom wall of the battery cell 20, the isolation part 114 is used on at least a part of the second wall 12 of the electrical cavity 11a, and the first wall 21 faces the isolation part 114. In addition, the isolation part 114 is used to isolate the electrical cavity 11a and the collecting cavity 11b, and the isolation part 114 is also used to form at least a part of the second passage 132, and thus the discharged matter passing through the pressure release means 211 passes through the isolation part 114 to be discharged from the electrical cavity 11a. For convenience of explanation, the embodiment of the present application mainly takes the case where the second wall 12 is the isolation part 114 as an example, but the embodiment of the present application 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] Also, for example, as shown in Fig. 4, the housing 11 further includes at least one beam 113, where the beam 113 is located between the multiple battery cells 20, and the beam 113 is used to increase the structural strength of the housing 11. Also, the beam 113 is 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, a left one and a right one, and the beam 113 is considered as one wall of the electrical cavity 11a.

[0087] Therefore, the second wall 12 may be a beam 113, and the embodiment of the present application is not limited thereto. Specifically, the beam 113 may be a hollow structure, and the hollow structure is used to form the collection cavity 11b, that is, the beam 113 is a wall shared by the electrical cavity 11a and the collection cavity 11b. Specifically, when the isolation part 114 and the protective member 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 part of the collection cavity 11b formed by the isolation part 114 and the protective member 115 is connected to the hollow structure of the beam 113, 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 is mainly described using an example in which the isolation part 114 is the second wall 12, but the present embodiment is not limited to this, and the relevant 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, in the present embodiment, the target structure includes the second wall 12, that is, the effluent discharged from the pressure relief means 211 can pass through the second wall 12 and be discharged from the battery cell 20. In this manner, by rationally setting the melting point of the second wall 12, the effluent discharged from the pressure relief means 211 can quickly destroy the second wall 12 and be discharged from the battery cell 20, which further improves the safety of the battery 10.

[0090] Optionally, at least a part of the first passage 131 in the embodiment of the present application may be provided between the first wall 21 and the second wall 12, where the first passage 131 may be realized in various ways. For example, as shown in FIG. 2 to FIG. 4, the battery 10 further includes a connection structure 14, the connection structure 14 is provided between the first wall 21 and the second wall 12, the connection structure 14 is used to form at least a part of the first passage 131, and the target structure includes the connection structure 14. When at least a part of the first passage 131 is realized by the connection structure 14, when the battery cell 20 does not generate thermal runaway, the connection structure 14 realizes the relative fixation between the first wall 21 and the second wall 12 and the sealing between the first wall 21 and the second wall 12, while the specific shape and position of the connection structure 14 can be reasonably set to adjust the position of the first passage 131, and further realize the directional discharge of the waste that has passed through the first passage 131, 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 by passing 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 connection structure 14 can realize at least a part of the first passage 131 in various ways. FIG. 5 shows a schematic diagram of a local structure of a battery 10 in the present embodiment, for example, FIG. 5 shows a schematic diagram of a local structure of the battery 10 shown in FIG. 4, and FIG. 5 shows a top view of the schematic structure of the battery 10. For example, as shown in FIG. 4 and FIG. 5, the connection structure 14 is provided with a flow path 141, and the first passage 131 includes a flow path 141. The effluent discharged through the pressure release means 211 can be discharged into the electrical cavity 11a through the flow path 141. In this way, the position of the flow path 141 can be reasonably set to realize directional discharge of the effluent, which reduces the impact of the effluent on individual components in the electrical cavity 11a, and further improves the safety of the battery 10.

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

[0093] As can be understood, the dimensions of the flow passage 141 in the embodiment of the present application may be set according to the actual application. For example, the radial dimension of the flow passage 141 is less than 2 mm or 2 mm, and the radial direction of the flow passage 141 is perpendicular to the flow direction of the waste in the flow passage 141, thereby avoiding the dimension of the flow passage 141 being too large to avoid excessive waste flowing through the flow passage 141, and also avoiding the size of the particles of the waste flowing through the flow passage 141 being too large, and has a filtering effect on the waste, and further reduces the influence of the waste of the thermal runaway battery cell 10 on other battery cells 20, and avoids the thermal diffusion of the battery 10 as much as possible. Specifically, when the flow passage 141 is a through hole, the radial dimension of the flow passage 141 may be the maximum value of the hole diameter of the flow passage 141, and when the flow passage 141 is a groove, the radial dimension of the flow passage 141 may be the maximum value of the depth or width of the groove, but the embodiment of the present application is not limited thereto.

[0094] As can be understood, a filler may be provided in the flow passage 141, the connection structure 14 includes the filler, and the target structure includes the filler. By reasonably setting the melting point of the filler, the filler can be used to seal the flow passage 141 when the pressure release means 211 is not working, and can be destroyed, for example melted, when the pressure release means 211 is working, so that the flow of the flow passage 141 is conducted, and the sealing of the electrical cavity 11a can be improved to avoid affecting or destroying the battery cell 20 when the battery cell 20 is not generating thermal runaway. Wherein, the material of the filler can be selected according to the actual application, for example, the material of the filler can 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 connection structure 14. As shown in Figs. 4 to 5, the connection 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 connection 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 connection 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 connection structure 14, i.e., the opening of the groove faces the second wall 12.

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

[0097] As can be understood, the extending direction of the flow passage 141 in the embodiment of the present application may be set according to the actual application. For example, the extending direction of the flow passage 141 can be reasonably set according to the positional relationship between the electrode terminal 212 of the battery cell 20 and the pressure release means 211, thereby preventing the discharged matter from affecting the electrode terminal 212 and the bus part 30 connected to the electrode terminal 212.

[0098] For example, as shown in Figures 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 provided to face the first wall 21, the extension direction of the flow path 141 is not limited. For example, the flow path 141 may include one or more X-direction first flow paths 141a extending along a first direction X provided in the connection structure 14 and / or one or more Y-direction second flow paths 141b extending along a second direction Y provided in the connection structure 14, or the flow path 141 may further include flow paths in other directions provided in the connection structure 14, and the embodiment of the present application is not limited thereto. In that case, the first direction X and the second direction Y are perpendicular to each other, and for example, the first direction X may be the thickness direction of the battery cell 20 as shown in Figures 4 and 5. Furthermore, the altitude 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, unlike 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 with the first wall 21, or the electrode terminal 212 is located on the first wall 21, the direction of the flow path 141 can be reasonably set to avoid the influence of the discharge on the electrode terminal 212, for example, to avoid a short circuit between different bus components 30 connected to the electrode terminal 212 caused by metal scrap in the discharge, and further improve the safety of the battery 10.

[0100] In the embodiment of the present application, the connection structure 14 may form at least a part of the first passage 131 in another manner. For example, the connection structure 14 is used to be broken when the pressure release means 211 operates 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 connection structure 14, and the material of the connection structure 14 can be reasonably selected to obtain a suitable melting point of the connection structure 14, so that the connection structure 14 is broken when the pressure release means 211 operates to form a gap to form the first passage, and the connection structure 14 does not need to have an additional structure, which is more simple and can ensure the sealing property of the battery cell 20 during normal use.

[0101] Specifically, in the embodiment of the present application, the destruction of the connection structure 14 includes the destruction of at least a part of the connection structure 14. For example, when the pressure release means 211 operates, only the exterior of the connection structure 14 is destroyed, and the internal parts of the exposed part of the connection structure 14 are not destroyed, or the internal structure of the connection structure 14 is destroyed, for example, the connection structure 14 may be a multi-layer structure, and some structural layers of the multi-layer structure may be destroyed, or the entire connection structure 14 may be destroyed, and the embodiment of the present application is not limited thereto.

[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 relief means 211, and the relief opening 142 is used to provide a deformation space when the pressure relief means 211 operates, preventing the connecting structure 14 from blocking the pressure relief means 211 and preventing the pressure relief means 211 from not operating in a timely manner, and the relief opening 142 allows the discharged matter that has passed through the pressure relief 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 deformation space for the pressure relief means 211, so that the discharged matter through the pressure relief means 211 can flow out 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 through the relief opening 142 to the electrical cavity 11a. 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 in 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 opening 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 in the embodiment of the present application may be provided according to actual applications, for example, the connection structure 14 may include at least one of a bracket, a heat conductive 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 cell 20 provided between the first wall 21 and the second wall 12.

[0106] Optionally, the connection structure 14 may include a thermal conduction pad provided between the first wall 21 and the second wall 12, so that the thermal conduction pad can dissipate heat from the battery cell 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 cell 20 to the thermal management component to timely adjust the temperature of the battery cell 20 and ensure normal use of the battery cell 20. For example, as shown in FIGS. 4 to 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 connection 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 Figures 4 to 5, the connection structure 14 may include a sealing pad, which 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, affixing 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 can be understood, the thermal conduction pad, the sealing pad and the binder may be used alone or in combination. For example, as shown in Fig. 4-5, the sealing pad may be provided on at least one edge of the thermal conduction pad, for example, the sealing pad may be provided on two opposite edges of the thermal conduction pad, respectively, to dissipate heat and improve the sealing between the first wall 21 and the second wall 12. And the binder may be used to fix the sealing pad and the thermal conduction pad to the battery cell 20 or to the second wall 12, to improve the stability of the battery 10.

[0110] As will be understood, the materials of the thermal conduction pad, the sealing pad and the binder in the embodiments of the present application can all be selected according to the actual application. For example, the material of the thermal conduction pad may include thermally conductive silica gel. Also, for example, the material of the sealing pad may include at least one of silicone rubber, polypropylene (PP), soluble polytetrafluoroethylene (Polyfluoroalkoxy, PFA) and polyimide (PI). For example, the material of the binder may include at least one of epoxy structural adhesive, acrylate structural adhesive, polyimide structural adhesive, maleimide structural adhesive, urethane structural adhesive and acrylic structural adhesive. Also, for example, the material of the binder layer may include a polymer adhesive and a thermally conductive material, the material of the polymer adhesive may include at least one of epoxy resin, organic silica gel and polyimide, and the thermally conductive material may be Al. 2 O 3 , ZnO, BeO, AlN, Si 3 N4, BN, SiC, B 4 C, carbon nanotubes, and graphite nanosheets, but the embodiments of the present application are not limited thereto.

[0111] Optionally, the first passage 131 of the embodiment of the present application 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 embodiment of the present application, and the gap is used to form at least a part of the first passage 131, thus reducing the sealing requirement of the electrical cavity 11a, especially the sealing requirement of the second wall 12, thereby reducing the processing difficulty of the battery 10 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 can 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] In the present embodiment, as shown in Figures 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, i.e., 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 the effluent from entering the electrical cavity 11a and causing a short circuit between the battery cells 20 or thermal diffusion, thereby affecting 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 can be understood, the pressure relief area 121 of the embodiment of the present application can be realized in various ways. FIG. 6 and FIG. 7 respectively show possible structural schematic diagrams of the battery 10 of the embodiment of the present application. As shown in FIG. 6 and FIG. 7, the pressure relief area 121 is a through hole penetrating the second wall 12, the through direction is the thickness direction of the second wall 12, and the second passage 132 includes a through hole. When the pressure relief area 121 is a through hole, it is convenient for processing, and the exhaust discharged through the pressure relief means 211 can be quickly released. However, when the pressure relief area 121 is a through hole, the pressure relief means 211 is exposed, and the pressure relief means 211 is easily affected by the external environment during the use of the battery 10, which may even lead to the breakdown of the pressure relief means 211.

[0117] 6 and 7, the battery 10 further includes a sealing structure 15, the sealing structure 15 is used to seal the through-hole, the sealing structure 15 is used to break the through-hole to form at least a part of the second passage 132 when the pressure release means 211 operates, and the target structure includes the sealing structure 15. When the pressure release area 121 is a through-hole, the melting point of the sealing structure 15 can be reasonably set to maintain the sealing of the electrical cavity 11a and protect the pressure release means 211 from the external environment during the normal use of the battery cell 20; meanwhile, when the battery cell 20 generates thermal runaway, the sealing structure 15 is broken in a timely manner to expose the through-hole and form the second passage 132, so that the exhaust of the battery cell 20 can pass through the through-hole and be exhausted 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 embodiment of the present application may be set according to the actual application. For example, as shown in FIG. 6, the sealing structure 15 is provided on the surface facing the first wall 21 of the second wall 12, and / or, for example, for convenience of processing, as shown in FIG. 7, the sealing structure 15 is provided on the surface facing the first wall 21 of the second wall 12. Also, as shown in FIG. 6, when the sealing structure 15 is provided on the surface facing the first wall 21 of the second wall 12, the sealing structure 15 is at a small distance from the pressure release means 211, and is quickly broken by the discharge of the pressure release means 211, so that the influence on the operation of the pressure release means 211 can be avoided, and the discharge can be timely discharged into the collection cavity 11b. As shown in FIG. 7, when the sealing structure 15 is provided on the surface facing the first wall 21 of the second wall 12, 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, and the influence on the pressure release means 211 can be avoided.

[0119] FIG. 8 shows another possible structural schematic diagram of the battery 10 of the embodiment of the present application. As shown in FIG. 8, the pressure release area 121 is a weak area of ​​the second wall 12, which is broken when the pressure release means 211 is operated to form at least a part of the second passage 132. When the pressure release means 211 is operated, the weak area is broken, and the discharged material from the battery cell 20 provided with the pressure release means 211 passes through the weak area to be discharged from the electrical cavity 11a, for example, through the weak area to enter the collection cavity 11b. By making the pressure release area 121 a weak area, when the pressure release means 211 is not operated, for example, during the normal use of the battery 10, the second wall 12 is in a sealed state, effectively protecting the pressure release means 211 from failure due to external force destruction, and when the battery cell 20 experiences thermal runaway, the weak area is broken in a timely manner to discharge the discharged material from the electrical cavity 11a, avoiding thermal runaway and improving the safety of the battery 10.

[0120] As can be understood, when the target structure includes a weak area, by reasonably setting the melting point of the weak area, the weak area has sufficient strength during the 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; meanwhile, when the battery cell 20 generates thermal runaway, the weak area can be destroyed in a timely manner, for example, melted in a timely manner to form the second passage 132, so that the discharged matter of the battery cell 20 can pass through the destroyed pressure relief area 121 and be discharged from the electrical cavity 11a, thereby avoiding thermal runaway and improving the safety of the battery 10.

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

[0122] 2, the second wall 12 is provided with a groove that corresponds to the pressure release means 211 and has an 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 the bottom wall is made the weakened area for convenience in processing.

[0123] As can be understood, the first passage 131 in the embodiment of the present application 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 housing 11 of the battery 10, which is used to discharge the effluent passing through the first passage 131 from the housing 11, thereby avoiding thermal diffusion caused by the accumulation of the effluent in the housing 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 for 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, when the collection cavity 11b is not provided, the effluent may be discharged directly from the housing 11. Alternatively, for example, the collection cavity 11b is provided to discharge the effluent to the collection cavity 11b, but since the space of the collection cavity 11b is limited, a second balancing valve may be provided on the wall of the housing 11 to discharge the effluent discharged from the second passage 132 from the housing 11, thereby, for example, discharging the effluent from the battery 10 through the collection cavity 11b, avoiding thermal diffusion or explosion due to 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 on the wall forming the collection cavity 11b.

[0125] The battery 10 of the embodiment of the present application 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, and the discharge passage 13 is connected to the inside of the battery cell 20 through the pressure relief means 211 when the pressure relief means 211 operates, so that the discharged matter inside the battery cell 20 can be discharged through 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. By rationally setting the a / b value, the discharged matter inside the battery cell 20 can be discharged in a timely manner, and the safety of the battery 10 is improved.

[0126] Although the present application has been described with reference to the preferred embodiments, various modifications can be made and the elements thereof can 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 can 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) including 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 inside of the battery cell (20) through the pressure release means (211) when the pressure release means (211) is operated; Including, Here, the battery is characterized in that it 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 a target structure for forming the exhaust passage (13).

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

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

4. The battery according to any one of claims 1 to 3, characterized in that the melting point b value of the target structure is in the range of 100°C to 2000°C.

5. 5. The battery according to claim 1, wherein the electrical cavity (11a) includes a second wall (12), and the first wall (21) faces the second wall (12).

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

7. 7. The battery according to claim 5 or 6, characterized in that the exhaust passage (13) includes a first passage (131), the first passage (131) being used to exhaust exhaust from the pressure relief means (211) to the electrical cavity (11a).

8. 8. The battery of claim 7, further comprising 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 comprising the connection structure (14).

9. The battery according to claim 8, characterized in that the connection structure (14) is provided with a flow path (141), and the first passage (131) includes the flow path (141).

10. 10. The battery of claim 8 or 9, wherein the connection structure (14) is adapted to be broken when the pressure release means (211) is operated to form a gap between the first wall (21) and the second wall (12), and the first passage (131) includes the gap.

11. The battery according to any one of claims 8 to 10, characterized in that the connection 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.

12. The battery according to any one of claims 5 to 11, characterized in that 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 relief means (211).

13. The battery of claim 12, characterized in that the second wall (12) is provided with a pressure relief area (121) corresponding to the pressure relief means (211), the pressure relief area (121) being used to form at least a part of the second passage (132).

14. The battery of claim 13, 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.

15. The battery of claim 14, 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 operated to cause the through hole to form at least a portion of the second passage (132), and the target structure comprising the sealing structure (15).

16. the sealing structure (15) is provided on the face of the second wall (12) facing the first wall (21); and / or 16. The battery according to claim 15, characterized in that the sealing structure (15) is provided on a face of the second wall (12) remote from the first wall (21).

17. 14. The battery of claim 13, wherein the pressure relief area (121) is a weakened area of ​​the second wall (12), the weakened area being adapted to break when the pressure relief means (211) is activated to form at least a portion of the second passageway (132).

18. The battery of claim 17 , wherein the target structure comprises the weakened area.

19. 19. A battery according to claim 17 or 18, characterized in that the thickness of the weakened area is smaller than the thickness of the area of ​​the second wall (12) situated around the weakened area.

20. The battery according to any one of claims 17 to 19, characterized in that 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 a bottom wall of the groove.

21. The housing (11) is The battery according to any one of claims 12 to 20, further comprising a collection cavity (11b) for collecting discharged matter discharged through the second passage (132) when the pressure release means (211) is operated.

22. 22. The battery of claim 21, further comprising an isolation component (114) for isolating the electrical cavity (11a) and the collection cavity (11b).

23. 23. The battery of claim 22, wherein the isolation piece (114) is used to define at least a portion of the second passageway (132).

24. An electrical device comprising a battery according to any one of claims 1 to 23, characterized in that said battery is used to provide electrical energy to said electrical device.

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