Battery pack, safety control method thereof, and power consumption device

Abstract

An embodiment of the present application provides a battery pack, a safety control method thereof, and a power consumption device, in which the battery pack (200) includes a housing assembly (201), a plurality of battery cells (100) provided in the housing assembly (201), and a safety protection mechanism (1) provided in the housing assembly (201) and having a first state and a second state, where when the safety protection mechanism (1) is in the first state, the plurality of battery cells (100) are insulated from the housing assembly (201), and when a preset trigger condition is satisfied, the safety protection mechanism (1) is in the second state, and when the safety protection mechanism (1) is in the second state, at least some of the battery cells (100) are electrically connected to the housing assembly (201).

Description

[Technical Field]

[0001] The present application relates to the field of battery technology, and in particular to a battery pack and its safety control method, and a power consumption device. [Background technology]

[0002] Batteries such as lithium-ion batteries are already widely used in electric vehicles due to their advantages such as high energy density, high power density, high cycle life, and long storage life.

[0003] However, improving the in-use safety of batteries in electric vehicles has traditionally been one of the industry's biggest challenges. Summary of the Invention

[0004] The purpose of this application is to improve the safety of batteries during use.

[0005] According to a first aspect of the present application, there is provided a battery pack including: a housing assembly; a plurality of battery cells provided in the housing assembly; and a safety protection mechanism provided in the housing assembly and having a first state and a second state, wherein when the safety protection mechanism is in the first state, the plurality of battery cells are insulated from the housing assembly, and when a preset trigger condition is satisfied, the safety protection mechanism is in the second state, and when the safety protection mechanism is in the second state, at least some of the battery cells are electrically connected to the housing assembly.

[0006] In this embodiment, when an abnormal battery cell is detected and a preset trigger condition is met, the battery pack can change the safety protection mechanism from a first state to a second state, thereby causing at least some of the battery cells to be electrically connected to the housing assembly in an autonomous and controllable manner, and forming an equipotential body between at least some of the battery cells and the housing assembly, thereby preventing high-voltage ignition from occurring within the battery pack and timely adjusting the battery pack from the abnormal state to a stable and controllable state.

[0007] Furthermore, inside the battery pack, at least some of the battery cells are electrically connected to the housing assembly, causing a breakdown point to appear, and by switching the high-voltage system within the battery pack to multiple equipotential components, the battery pack can be protected and the safety of its operation can be improved.

[0008] In some embodiments, when the security mechanism is in the second state, the number of battery cells electrically connected to the housing assembly is at least three.

[0009] In this embodiment, when the battery pack satisfies a preset trigger condition, the safety protection mechanism is put into a second state, and at least three battery cells are electrically connected to the housing assembly, thereby forming at least three breakdown points within the battery pack, reducing the voltage division between two breakdown points across the entire high-voltage load, reducing the risk of high-voltage ignition, and allowing the battery pack to be timely adjusted from an abnormal state to a stably controllable state, thereby improving the safety of the battery cells within the battery pack as well as the safety of the control electrical box connected to the battery pack.

[0010] In some embodiments, when the safety mechanism is in the second state, all of the battery cells are electrically connected to the housing assembly.

[0011] In this embodiment, when the battery pack satisfies a preset trigger condition, the safety protection mechanism is put into a second state, and all battery cells in the battery pack are electrically connected to the housing assembly, thereby forming a breakdown point in each battery cell in the battery pack and minimizing the voltage division between the two breakdown points of the entire high-voltage load. Even if an abnormality occurs in any one battery cell, the risk of high-voltage ignition is reduced, and the battery pack can be timely adjusted from an abnormal state to a stably controllable state, which not only improves the safety of the battery cells in the battery pack but also improves the safety of the control electrical box connected to the battery pack.

[0012] In some embodiments, the safety protection mechanism includes a plurality of sub-protective members, each of which is arranged in one-to-one correspondence with the plurality of battery cells, and each of which has a first state and a second state, and the sub-protective members are configured to insulate the corresponding battery cell from the housing assembly in the first state and to electrically connect the corresponding battery cell to the housing assembly in the second state.

[0013] This embodiment corresponds to installing multiple sub-protective elements in a one-to-one correspondence with multiple battery cells and installing the safety protection mechanism as multiple independent sub-protective elements, which allows for flexible installation of the sub-protective elements for a specific number of battery cells located in specific positions, simplifies the structure of the sub-protective elements, reduces the volume of the sub-protective elements, and facilitates installation in a compact internal space of the battery pack. Furthermore, even if a sub-protective element malfunctions after the battery pack has been operating for a long period of time, the safety protection function can be achieved by relying on the derating of other sub-protective elements, further improving the operational safety of the battery pack.

[0014] In some embodiments, the safety mechanism is provided between the battery cell and the bottom or top wall of the housing assembly.

[0015] This embodiment can achieve safety protection for some or all of the battery cells in the same layer by simply adding a predetermined amount of space in the height direction of the battery pack, thereby ensuring a compact internal space of the battery pack while protecting a larger number of battery cells using a minimum amount of space, thereby improving the operational safety of the battery pack.

[0016] In some embodiments, the predetermined trigger condition includes at least one of the following: a temperature inside the housing assembly reaching a predetermined temperature; an air pressure inside the housing assembly reaching a predetermined pressure; a smoke density inside the housing assembly reaching a predetermined density; and a battery management system of the battery pack emitting an electrical signal indicating an abnormality in a battery cell.

[0017] This embodiment facilitates accurate determination of the occasion when the safety protection mechanism switches to the second state, making it possible to quantitatively determine whether an abnormality has occurred in the battery pack, ensuring safety when an abnormality occurs in the battery pack, and preventing the safety protection mechanism from being inadvertently turned on.

[0018] In some embodiments, the safety mechanism is configured to transition from a first state to a second state by mechanical action when a preset trigger condition is met.

[0019] In this embodiment, when a preset trigger condition is met, the safety protection mechanism can be changed into a different state through mechanical operation, which ensures reliable operation and thereby realizes reliable safety protection for the battery cell, and is advantageous in realizing bidirectional switching between the first state and the second state.

[0020] In some embodiments, the safety protection mechanism includes a plurality of sub-protective elements each installed on a different battery cell, each sub-protective element having a first state and a second state, the battery cell includes a housing, the sub-protective elements are provided in the housing, and the sub-protective elements are configured to generate a mechanical action by the expansion force of the housing to change from the first state to the second state when a preset trigger condition is satisfied.

[0021] In this embodiment, the safety protection mechanism is configured as multiple independent sub-protective members, which allows for flexible installation of the sub-protective members for a specific number and specific positions of battery cells, simplifies the structure of the sub-protective members, reduces their volume, and facilitates installation in a compact interior space of the battery pack. Furthermore, even if a sub-protective member malfunctions after the battery pack has been in operation for a long period of time, the safety protection function can be achieved by relying on the derating of other sub-protective members, thereby further improving the operational safety of the battery pack.

[0022] Furthermore, by providing the sub-protective member in the housing, when an abnormality occurs in the battery cell, the expansion force generated inside acts on the housing, causing the housing to deform and causing a mechanical movement in the sub-protective member, changing it from a first state to a second state. This method of triggering the operation of the sub-protective member eliminates the need to install a status monitoring member, and by directly utilizing the structural change in the battery cell itself when an abnormality occurs to activate the sub-protective member, it simplifies the structure and control method of the battery pack safety protection system, reduces malfunction of the sub-protective member due to failure of electronic components, improves the operational reliability of the sub-protective member, and thereby improves the operational safety of the battery pack.

[0023] In some embodiments, the housing is provided with a pressure relief member, and the sub-protective member is provided on the pressure relief member, and is configured such that when the pressure relief member receives an expansion force and is turned on, it generates a mechanical action and changes from a first state to a second state.

[0024] In this embodiment, a sub-protective element is provided on the pressure relief element. When thermal runaway occurs in the battery cell and the internal pressure exceeds a preset pressure, the pressure relief element is turned on. After the pressure relief element is turned on, a part of the structure moves outward and opens. The movement range of the pressure relief element during its opening process is relatively large, so that the sub-protective element generates a mechanical movement to reliably drive the sub-protective element to change from the first state to the second state, and the sub-protective element is turned on in a timely manner, thereby improving the safety of the battery pack operation.

[0025] In some embodiments, the sub-protective member includes an elastic element and a wrap, the elastic element is connected between the housing and the wrap, and when the sub-protective member is in the second state, the wrap is electrically connected to the housing assembly.

[0026] In this embodiment, the expansion of the battery cell housing can be utilized to act on the wrap by the elastic element, and the elastic action applied to the wrap by the elastic element makes it easier to electrically connect the wrap and the housing assembly, and even if the electrical connection is maintained for a short time, the high voltage of the battery cell can be quickly released, preventing the occurrence of high-voltage ignition and improving the operational safety of the battery pack.

[0027] In some embodiments, the safety protection mechanism includes a plurality of sub-protective members each installed on a different battery cell, each sub-protective member having a first state and a second state, wherein the sub-protective members include a conductive portion, an insulating portion, and a heating portion, the conductive portion is connected to the battery cell, the insulating portion covers the conductive portion, and a gap is formed between the conductive portion and the insulating portion, the heating portion is provided in the gap, and the sub-protective members are configured to be changed from the first state to the second state by the heating portion releasing heat to destroy the insulating portion.

[0028] In this embodiment, when a preset trigger condition is met, the heat emitted by the heating unit is used to destroy the insulating unit, thereby establishing an electrical connection between the conductive unit and the housing assembly, and the heat emission is used to change the sub-protective member from the first state to the second state. This structure does not require the installation of a complex movement mechanism within the housing assembly, reducing the complexity of the structure, ensuring the insulating performance of the sub-protective member in the first state, and improving the reliability of the sub-protective member switching to the second state, thereby improving the operational safety of the battery pack.

[0029] In some embodiments, the heating portion includes a coil configured to be energized when a preset trigger condition is met to generate a magnetic field to heat and break down the insulation.

[0030] In this embodiment, when a preset trigger condition is met, the coils in the multiple sub-protective elements are spontaneously energized, and the current in the coils is used to generate a magnetic field and release heat, which can then be used to destroy the insulation. This method allows the amount of heat released to be flexibly controlled, ensuring the removal of the insulation and thereby ensuring the sub-protective elements are turned on when an abnormality occurs in the operation of the battery pack. Furthermore, this embodiment allows the controller to more accurately determine the occasion for turning on the safety protection mechanism and spontaneously control the multiple sub-protective elements to be turned on, which is advantageous for realizing synchronous turning on of multiple sub-protective elements.

[0031] In some embodiments, the insulating portion divides the gap between the conductive portion and the insulating portion into a first cavity and a second cavity, the first cavities of each of the multiple sub-protective members are connected to each other and contain an oxidizer, the second cavities of each of the multiple sub-protective members are connected to each other and contain a reducing agent, and the heating portion includes an oxidizer and a reducing agent, and is configured to react the oxidizer and the reducing agent by heating the conductive portion when a predetermined trigger condition is met, and destroy the insulating portion by the heat released by the reaction.

[0032] In this embodiment, if a preset trigger condition is met, heat generated when an abnormality occurs in a specific battery cell can be transferred to the corresponding conductive part, which melts the portion of the insulating part located between the first and second cavities of the insulating part. The oxidant and reductant then undergo a chemical reaction, releasing heat. The released heat is then used to destroy the insulating part, which in turn melts the insulating part located between the first and second cavities of the sub-protective parts corresponding to other battery cells. This causes the oxidant and reductant to react sequentially along the array path of the multiple battery cells, destroying all of the insulating parts in the multiple sub-protective parts. This embodiment can passively turn on the sub-protective parts when an abnormality occurs in the battery pack, thereby enabling the safety protection mechanism to be activated more timely and quickly.

[0033] In some embodiments, the battery pack further includes a controller configured to, when receiving a signal that satisfies a preset trigger condition, issue an activation signal to the safety mechanism, causing the safety mechanism to change from the first state to the second state.

[0034] In this embodiment, when an abnormality occurs in the operation of the battery pack, the controller automatically controls the safety protection mechanism to be turned on, and the controller can comprehensively evaluate the received signals, for example, only when the detection signal exceeds a predetermined threshold for a predetermined period of time to finally determine that a predetermined trigger condition is met, thereby preventing accidental deviation of the collected signals of the status monitoring component, more accurately determining when to turn on the safety protection mechanism, and preventing the battery pack from being discarded due to erroneous activation of the safety protection mechanism. Furthermore, the automatic control method can also cause the controller to take other safety protection measures after the safety protection mechanism is turned on, such as powering off or cooling the battery pack, or automatically turning on a pressure relief member on the housing assembly.

[0035] In some embodiments, the security mechanism is configured to change from the first state to the second state directly as a function of a preset trigger condition.

[0036] In this embodiment, when an abnormality occurs in the operation of the battery pack, there is no need for the controller to determine the environmental change and then issue an ON signal to the safety protection mechanism. Instead, the safety protection mechanism is passively turned on by directly relying on the environmental change of the housing assembly, which allows the safety protection mechanism to be turned on more timely and quickly. When the battery pack enters runaway mode, an equipotential body is quickly formed between the battery cells and the housing assembly, which forms multiple breakdown points within the battery pack and reduces the voltage division at the two breakdown points of the entire high-voltage load, preventing instantaneous high-voltage ignition and allowing the battery pack to quickly adjust from an abnormal state to a stable, controllable state, thereby avoiding further deterioration.

[0037] In some embodiments, the battery cell includes a housing, and the safety mechanism is configured to electrically connect the housing with the housing assembly when in the second state.

[0038] In this embodiment, if an abnormality occurs in the operation of the battery pack, the housing is electrically connected to the housing assembly, and the housing has a relatively large surface area, which makes it easy to install the safety protection mechanism, ensures reliable operation of the safety protection mechanism, and is located away from the electrical connections of the battery cells, preventing the operation of the safety protection mechanism from affecting the electrical connections. Furthermore, since the battery cells are covered with an insulating layer when the battery pack is operating normally, the insulation performance between the battery cells and the housing assembly can be reliably guaranteed when the safety protection mechanism is installed.

[0039] In some embodiments, the battery cells include a housing, the housing is provided with electrode terminals, and the battery pack further includes a bus bar member configured to electrically connect the electrode terminals of two of the battery cells, wherein the safety protection mechanism is configured to electrically connect at least one of the electrode terminals and the bus bar member to the housing assembly when in the second state.

[0040] In this embodiment, if an abnormality occurs in the battery pack, the safety protection mechanism operates to electrically connect at least one of the electrode terminals and the bus bar members to the housing assembly, and multiple battery cells in the battery pack are electrically connected via the bus bar members. Therefore, by simply installing at least one sub-protection member for multiple battery cells that are electrically connected, safety protection for the electrically connected multiple battery cells can be achieved, reducing the number of sub-protection members and simplifying the structure of the safety protection mechanism, reducing the space occupied by the safety protection mechanism within the housing assembly, and improving the energy density of the battery pack.

[0041] In some embodiments, the plurality of battery cells are divided into a plurality of battery modules, and the plurality of battery cells in each battery module are connected in series, in parallel, or in series-parallel fashion via busbar members. The safety protection mechanism includes a plurality of conductive members, and at least one conductive member is installed in each battery module. The conductive member is connected to an electrode terminal that is not connected to the busbar member. The exterior of the conductive member is covered with an insulating layer, and is configured to be electrically connected to the housing assembly after the insulating layer is broken, thereby changing from a first state to a second state.

[0042] In this embodiment, the safety protection mechanism is configured as a plurality of conductive members, which are used to be electrically connected to the housing assembly when a preset trigger condition is met, thereby enabling a plurality of battery cells in a battery module to be electrically connected to the housing assembly, reducing the number of conductive members, simplifying the structure of the safety protection mechanism, reducing the space occupied by the safety protection mechanism in the housing assembly, and improving the energy density of the battery pack.

[0043] According to a second aspect of the present application, there is provided a power consuming device, said power consuming device including a battery pack according to any of the above embodiments, wherein the battery pack is used to provide electrical energy to the power consuming device.

[0044] According to a third aspect of the present application, there is provided a safety control method for a battery pack, the safety control method comprising: placing a safety protection mechanism in a housing assembly of the battery pack in a first state to isolate the plurality of battery cells in the housing assembly from the housing assembly; and changing the safety mechanism from a first state to a second state when a preset trigger condition is met, so as to electrically connect at least some of the battery cells with the housing assembly.

[0045] In this embodiment, when an abnormal battery cell is detected and a preset trigger condition is met, the battery pack can change the safety protection mechanism from a first state to a second state, thereby causing at least some of the battery cells to be electrically connected to the housing assembly in an autonomous and controllable manner, and forming an equipotential body between at least some of the battery cells and the housing assembly, thereby preventing high-voltage ignition from occurring within the battery pack and timely adjusting the battery pack from the abnormal state to a stable and controllable state.

[0046] Furthermore, inside the battery pack, at least some of the battery cells are electrically connected to the housing assembly, causing a breakdown point to appear, and by switching the high-voltage system within the battery pack to multiple equipotential components, the battery pack can be protected and the safety of its operation can be improved.

[0047] In some embodiments, changing the security mechanism from the first state to the second state when a preset trigger condition is met comprises: When the controller receives a signal that satisfies a preset trigger condition, the controller issues an activation signal to the safety protection mechanism, causing the safety protection mechanism to change from the first state to the second state.

[0048] In this embodiment, when an abnormality occurs in the operation of the battery pack, the controller automatically controls the safety protection mechanism to be turned on, and the controller can comprehensively evaluate the received signals, for example, only when the detection signal exceeds a predetermined threshold for a predetermined period of time to finally determine that a predetermined trigger condition is met, thereby preventing accidental deviation of the collected signals of the status monitoring component, more accurately determining when to turn on the safety protection mechanism, and preventing the battery pack from being discarded due to erroneous activation of the safety protection mechanism. Furthermore, the automatic control method can also cause the controller to take other safety protection measures after the safety protection mechanism is turned on, such as powering off or cooling the battery pack, or automatically turning on a pressure relief member on the housing assembly. [Brief explanation of the drawings]

[0049] In order to more clearly explain the technical solutions of the embodiments of the present application, the following briefly introduces the drawings that need to be used in the embodiments of the present application, it is obvious that the drawings described below are only some embodiments of the present application, and those skilled in the art can derive other drawings based on the drawings without any creative efforts, and the drawings are not necessarily drawn to actual scale. [Figure 1]1A to 1C are structural schematic diagrams of some embodiments in which the battery pack of the present application is installed in a vehicle. [Figure 2] 1A-1C are exploded views of some embodiments of the battery pack of the present application. [Figure 3] 1A-1C are structural schematic diagrams of some embodiments of battery cells of the present application. [Figure 4] 1A-1C are exploded schematic views of some embodiments of battery cells of the present application. [Figure 5] 1 is a schematic diagram of a first embodiment of a battery pack of the present application, showing a safety protection mechanism in a first state; [Figure 6] FIG. 6 is a plan view of FIG. 5. [Figure 7] FIG. 6 is a side view of the sub-protective member in FIG. 5. [Figure 8] 6 is a schematic diagram of the safety mechanism in FIG. 5 in a second state; [Figure 9] FIG. 9 is an enlarged view of a portion A in FIG. 8. [Figure 10] FIG. 2 is a schematic diagram of an electrical connection state between a battery cell and a housing assembly in the battery pack of the present application. [Figure 11] 1 is a schematic diagram of the working principle of the safety protection mechanism in the battery pack of the present application; [Figure 12] FIG. 10 is a front view of a sub-protective member in a second embodiment of the battery pack of the present application. [Figure 13A] FIG. 13 is a side view of FIG. 12. [Figure 13B] FIG. 13B is a structural schematic diagram of a modified embodiment of FIG. 13A. [Figure 14] FIG. 10 is a structural schematic diagram of a safety protection mechanism in a third embodiment of the battery pack of the present application. [Figure 15] FIG. 15 is a plan view of FIG. [Figure 16] FIG. 16 is an enlarged view of a portion B in FIG. [Figure 17] 1 is a flowchart of some embodiments of a battery pack safety control method of the present application. [Figure 18] 1A to 1C are structural schematic diagrams of some embodiments of the safety control device of the battery pack of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0050] The following describes in more detail the embodiments of the present application in conjunction with the drawings and examples. The detailed description of the embodiments and the drawings are for illustrative purposes only to explain the principles of the present application, but are not intended to limit the scope of the present application, i.e., the present application is not limited to the described embodiments.

[0051] In describing the embodiments of the present application, the term "plurality" refers to two or more (including two); similarly, "sets" refers to two or more (including two sets); and "plurality" refers to two or more (including two).

[0052] This application employs descriptions of orientations or positional relationships indicated by terms such as "upper," "lower," "top," "bottom," "front," "rear," "inner," and "outer," which are for the purpose of describing this application only and do not indicate or imply that the referenced devices have a particular orientation or must be configured and operated in a particular orientation, and therefore cannot be understood as limitations on the scope of protection of this application.

[0053] It should be noted that the terms "first," "second," "third," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance. "Perpendicular" does not mean strictly perpendicular, but has a margin of error. "Parallel" does not mean strictly parallel, but has a margin of error. All directions appearing in the following description refer to directions shown in the drawings and do not limit the specific structure of this application.

[0054] It should be further explained that in the description of this application, unless otherwise clearly defined or limited, the terms "attached," "connected," and "coupled" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection, and may be a direct connection or an indirect connection via an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific circumstances.

[0055] The term "embodiment" as used herein means that the particular feature, structure, or characteristic described in connection with the embodiment may be included in at least some embodiments of the present application. Appearances of this phrase in various locations throughout the specification do not necessarily all refer to the same embodiment, nor are they mutually exclusive, independent, or alternative embodiments. Those skilled in the art can explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0056] The battery cells may include lithium ion secondary batteries, lithium ion primary batteries, lithium-sulfur batteries, sodium lithium ion batteries, sodium ion batteries, magnesium ion batteries, etc., but the embodiments of the present application are not limited thereto. The battery cells may have a cylindrical, flat, rectangular, or other shape, but the embodiments of the present application are not limited thereto. Battery cells are generally divided into three types based on packaging methods: cylindrical battery cells, rectangular battery cells, and pouch battery cells, but the embodiments of the present application are not limited thereto.

[0057] Current battery cells typically include a case and an electrode assembly housed within the case, with the case filled with an electrolyte. The electrode assembly is typically formed by stacking or winding a first electrode plate and a second electrode plate of opposite polarity, and typically includes an insulating member, such as a separator, between the first and second electrode plates. The portions of the first and second electrode plates coated with active material constitute the main body of the electrode assembly, while the portions of the first and second electrode plates not coated with active material constitute the first and second tabs, respectively. In a lithium-ion battery, the first electrode plate may be a positive electrode plate, including a positive electrode current collector and a positive electrode active material layer disposed on both sides of the positive electrode current collector. The material of the positive electrode current collector may be, for example, aluminum, and the positive electrode active material may be, for example, lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The second electrode plate may be a negative electrode plate, including a negative electrode current collector and a negative electrode active material layer disposed on both sides of the negative electrode current collector. The material of the negative electrode current collector may be, for example, copper, and the negative electrode active material may be, for example, graphite or silicon. Alternatively, the first electrode plate may be a negative electrode plate, and the second electrode plate is accordingly a positive electrode plate. The first tab and the second tab may both be located at one end of the body portion, or may be located at both ends of the body portion. During charging and discharging of the battery cell, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs are connected to the terminals to form a current circuit.

[0058] Current batteries still pose a relatively large potential safety risk during use, for example, the entire battery system may experience high-voltage fire during use. The inventors' research has revealed that this phenomenon occurs when a battery cell in a battery pack experiences thermal runaway, making it difficult for the generated high-temperature, flammable smoke to be quickly discharged and accumulating inside the casing, creating a high-temperature, high-pressure environment. This can lead to localized damage to the insulation design within the battery pack, resulting in high voltage in some battery cells. Furthermore, when the above problem occurs in a battery pack, the number and locations of high-voltage fires that occur are unclear, making it impossible to timely adjust the battery from an abnormal state to a stable, controllable state.

[0059] Furthermore, after the discharged materials in the battery cells are sputtered onto the electrical connection structure through the explosion-proof valve, a short circuit is likely to occur, or high-voltage ignition may affect other battery cells, and thus the thermal diffusion phenomenon of the battery cells may cause high-voltage arcing.As can be seen from this, thermal runaway not only has a high temperature effect, but can also worsen and cause high-voltage ignition in the battery pack.

[0060] In order to solve the above problems, the inventors came up with the idea of ​​autonomously controlling the voltage of a battery cell to a safe and stable level when thermal runaway or other abnormal phenomena occur during battery cell operation, thereby avoiding high-voltage ignition as much as possible.

[0061] Based on this improved concept, the present application proposes a battery pack, which includes: a housing assembly; a plurality of battery cells provided in the housing assembly; and a safety protection mechanism provided in the housing assembly and having a first state and a second state, wherein when the safety protection mechanism is in the first state, the plurality of battery cells are insulated from the housing assembly, and when a preset trigger condition is satisfied, the safety protection mechanism is in the second state, and when the safety protection mechanism is in the second state, at least some of the battery cells are electrically connected to the housing assembly.

[0062] In such a battery pack, when a preset trigger condition is met due to the occurrence of an abnormal battery cell, the safety protection mechanism can be changed from a first state to a second state, thereby causing at least some of the battery cells to be spontaneously and controllably electrically connected to the housing assembly, causing a breakdown point to appear inside the battery pack, causing at least some of the battery cells and the housing assembly to form an equipotential body, switching the high-voltage system within the battery pack to multiple equipotential components, preventing the occurrence of high-voltage ignition phenomena within the battery pack, and timely adjusting the battery pack from an abnormal state to a stably controllable state, thereby protecting the battery pack and improving the operational safety of the battery pack.

[0063] The battery cell of the embodiment of the present application is applied to a battery and a power consuming device that uses the battery.

[0064] The power consuming devices may be mobile phones, portable devices, laptops, battery cars, electric cars, steamships, spacecraft, electric toys and power tools, etc., for example, spacecraft include airplanes, rockets, space shuttles and spaceships, etc., electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric steamship toys and electric plane toys, etc., and power tools include metal cutting power tools, polishing power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, hammer drills, concrete vibrators and electric planers.

[0065] 1 , the power consumption device may be a vehicle 300, for example, a new energy vehicle, which may be a pure electric vehicle, a hybrid vehicle, or a range extender vehicle, or the power consumption device may be a drone or a steamship, etc. Specifically, the vehicle 300 may include an axle 301, wheels 302 connected to the axle 301, a motor 303, a controller 304, and a battery pack 200, where the motor 303 is used to drive the axle 301 to rotate, the controller 304 is used to control the operation of the motor 303, and the battery pack 200 may be installed at the bottom, head, or rear of the vehicle 300 and used to provide electrical energy for the operation of the motor 303 and other components in the vehicle.

[0066] As shown in FIG. 2 , the battery pack 200 includes a housing assembly 201 and battery cells 100. The battery pack 200 may include one or more battery cells 100. When the battery pack 200 includes multiple battery cells 100, the multiple battery cells 100 may be connected in series, parallel, or series-parallel. A series-parallel connection means that the multiple battery cells 100 may be connected in series or parallel. The multiple battery cells 100 may first be connected in series, parallel, or series-parallel to form a battery module, and then the multiple battery modules may be further connected in series, parallel, or series-parallel to form a whole and housed in the housing assembly 201. All the battery cells 100 may be directly connected in series, parallel, or series-parallel, and then the whole consisting of all the battery cells 100 may be housed in the housing assembly 201.

[0067] The interior of the housing assembly 201 has a hollow structure. For example, the housing assembly 201 may include a housing 201A and a cover 201B. The housing 201A is engaged with the cover 201B. For example, the housing 201A and the cover 201B may both be hollow rectangular parallelepipeds, each with only one side open. The opening of the housing 201A and the opening of the cover 201B may be disposed opposite each other, and the housing 201A and the cover 201B may be engaged with each other to form a housing having a sealed chamber. The housing 201A may be a rectangular parallelepiped with an opening and the cover 201B may be plate-shaped, or the cover 201B may be a rectangular parallelepiped with an opening and the housing 201A may be plate-shaped. The housing 201A and the cover 201B may be disposed opposite each other and engaged to form the housing assembly 201 having a sealed chamber. At least one battery cell 100 is combined with one another in parallel, series, or series-parallel connection, and then placed in a sealed chamber formed after the housing 201A and the cover 201B are engaged with each other.

[0068] In order to more clearly understand the improved principle of the battery pack of the present application, the structure of the battery cell 100 will be first described in detail.

[0069] 3 and 4, a battery cell 100 includes a case 10, an electrode assembly 30, an end cap 50, two electrode terminals 51 with opposite polarities, and two adapters 40. The case 10 has an opening 101, and the end cap 50 is fitted over the opening 101. The end cap 50 and the case 10 are connected to form a housing 100' for the battery cell 100. The outer surface of the housing 100' may be coated with an insulating layer 20 to improve the insulation of the battery cell 100. The end cap 50 may be provided with two electrode terminals 51 with opposite polarities.

[0070] The electrode assembly 30 is disposed within the case 10, which is filled with an electrolyte. Depending on actual usage needs, one or more electrode assemblies 30 may be provided. The electrode assembly 30 is formed by stacking or winding a first electrode plate and a second electrode plate of opposite polarity, and typically a separator is provided between the first electrode plate and the second electrode plate. The coated portions of the first electrode plate and the second electrode plate constitute the main body of the electrode assembly 30, and the uncoated portions of the first electrode plate and the second electrode plate respectively constitute two tabs 30' of opposite polarity. Each of the two tabs 30' is electrically connected to an electrode terminal 51 of the same polarity via an adapter 40.

[0071] Optionally, the end cap 50 may further include a pressure relief member 52, which is an element or member that operates to release the internal pressure or temperature of the battery cell 100 when the internal pressure or temperature reaches a predetermined threshold. The design of this threshold varies according to design needs. The threshold may be determined by one or more of the materials of the first electrode plate, the second electrode plate, the electrolyte, and the separator of the battery cell 100. The pressure relief member 52 may take the form of an explosion-proof valve, an air valve, a pressure relief valve, a safety valve, etc., and may specifically be a pressure- or temperature-sensitive element or structure. That is, when the internal pressure or temperature of the battery cell 100 reaches a predetermined threshold, the pressure relief member 52 operates, or a fragile structure provided in the pressure relief member 52 breaks, thereby forming an opening or channel for releasing the internal pressure or temperature.

[0072] The term "operation" referred to in this application refers to the pressure relief member 52 operating or being activated to a certain state, thereby releasing the internal pressure and temperature of the battery cell 100. The operation of the pressure relief member 52 may include, but is not limited to, rupturing, crushing, tearing, or opening of at least a portion of the pressure relief member 52. When the pressure relief member 52 is operated, the internal waste of the battery cell 100 is discharged to the outside through the operating portion. In this manner, pressure and temperature relief can be generated in the battery cell 100 when the pressure or temperature is controllable, thereby avoiding the occurrence of potentially more serious accidents.

[0073] Here, the emissions from the battery cell 100 mentioned herein include, but are not limited to, electrolyte, dissolved or split positive and negative electrode plates, separator fragments, high-temperature and high-pressure gases (e.g., combustible gases such as CH4 and CO) generated by the reaction, flames, etc.

[0074] In some embodiments, as shown in FIGS. 5 to 9 , the present application provides a battery pack 200, which includes a housing assembly 201, a plurality of battery cells 100 provided in the housing assembly 201, and a safety protection mechanism 1 provided in the housing assembly 201 and having a first state and a second state, wherein when the safety protection mechanism 1 is in the first state, the plurality of battery cells 100 are insulated from the housing assembly 201, and when a preset trigger condition is satisfied, the safety protection mechanism 1 is in the second state, and when the safety protection mechanism 1 is in the second state, at least some of the battery cells 100 are electrically connected to the housing assembly 201.

[0075] The structure of the housing assembly 201 has been described in detail above. A plurality of battery cells 100 may be directly connected in series, parallel, or series-parallel to be integrated into the battery pack 200. Alternatively, as shown in FIGS. 5 and 6 , a plurality of beams 201C are provided within the housing 201A of the housing assembly 201. The beams 201C divide the interior space of the housing 201A into a plurality of receiving cavities 201D, and a plurality of battery cells 100 are provided within each receiving cavity 201D and connected in series, parallel, or series-parallel to form a battery module 200′. The housing assembly 201 may be manufactured using a metal material, such as aluminum, steel, or other alloy material. An insulating layer may be provided on the exterior of the housing assembly 201 to improve the operational safety of the battery pack 200.

[0076] The safety protection mechanism 1 is provided in the housing assembly 201, and may be provided selectively at at least one of the following positions: between the battery cell 100 and the bottom wall of the housing 201A; between the battery cell 100 and the side wall of the housing 201A; between the battery cell 100 and the beam 201C; and between the battery cell 100 and the top wall of the cover 201B. The installation position of the safety protection mechanism 1 may be selected to facilitate electrical connection between the battery cell 100 and the housing assembly 201. Optionally, the safety protection mechanism 1 may be directly attached to the inner wall of the housing assembly 201, or may be attached to the inner wall of the housing assembly 201 via a fixing plate; for example, the fixing plate may be a water-cooling plate or an underguard plate, or may be fixed to the battery cell 100.

[0077] The security mechanism 1 has a first state and a second state, the first state being the initial state of the security mechanism 1 and the second state being the ON state of the security mechanism 1.

[0078] Optionally, the security mechanism 1 can only change unilaterally from the first state to the second state, and cannot recover to the first state after reaching the second state.

[0079] Optionally, the safety protection mechanism 1 may be switched between a first state and a second state. For example, the safety protection mechanism 1 may be configured to be in the second state and to return to the first state when a preset trigger condition is no longer present. After the safety risk of the battery pack 200 is reduced, the safety protection mechanism 1 may be controlled to be off, thereby disconnecting all of the battery cells 100 from the housing assembly 201. Because some of the battery cells 100 electrically connected to the housing assembly 201 may lose electrical connection due to the shaking and vibration of the vehicle while it is running, this reduces the number of battery cells 100 with breakdown points, thereby increasing the voltage division between adjacent breakdown points. In this case, electrical connections still exist between the housing assembly 201 and some of the battery cells 100, which poses an operational risk when an operator removes the discarded battery pack 200. Automatically restoring the safety protection mechanism 1 to the first state reduces operational risks when an operator removes the discarded battery pack 200, thereby improving operational safety.

[0080] When all the battery cells 100 in the battery pack 200 are operating normally, the safety protection mechanism 1 is in a first state, and all the battery cells 100 in the battery pack 200 are insulated from the housing assembly 201, ensuring the insulation performance when the battery pack 200 is operating normally. The outer surface of the housing 100' of the battery cells 100 may be covered with an insulating layer 20. For example, the insulating layer 20 may be made of, but is not limited to, a PET (polyethylene terephthalate) film, a PI (polyimide) film, a PP (polypropylene) film, a PBT (polybutylene terephthalate) film, a PVC (polyvinyl chloride) film, or a PPS (polyphenylene sulfide) film. The insulating layer 20 may be attached to the surface of the housing 100' by adhesive.

[0081] When a thermal runaway or other abnormality occurs in a battery cell 100 in the battery pack 200 and a preset trigger condition is met, preventing the battery pack 200 from operating normally, the safety protection mechanism 1 changes from a first state to a second state, and at least some of the battery cells 100 in the battery pack 200 are electrically connected to the housing assembly 201, thereby stabilizing and controlling the voltage of the battery pack 200. Optionally, any conductive portion of the battery cell 100 may be electrically connected to the housing assembly 201. For example, the conductive portion of the battery cell 100 may be the housing 100′, the electrode terminal 51, or a bus bar member connected to the electrode terminal 51. Optionally, the battery cell 100 may be electrically connected to the housing assembly 201 itself, or may be electrically connected to a structural component provided in the housing assembly 201 and conductively connected to the housing assembly 201, thereby electrically connecting the battery cell 100 to the housing assembly 201 via the structural component.

[0082] As shown in FIG. 10 , the operating principle of such a battery pack 200 is that, when the battery pack 200 operates normally, a plurality of preset lap points are formed between the plurality of battery cells 100 and the housing assembly 201 by the safety protection mechanism 1; when the safety protection mechanism 1 is in a first state, the safety protection mechanism 1 is not activated, and the preset lap points are in a state where the battery cells 100 and the housing assembly 201 are disconnected; and when an abnormality occurs in a battery cell 100 in the battery pack 200, the safety protection mechanism 1 is activated, and the state is changed from the first state to the second state, and the preset lap points are in a state where the battery cells 100 are electrically connected to the housing assembly 201.

[0083] In this embodiment, when an abnormal battery cell 100 is detected and a preset trigger condition is met, the battery pack 200 can change the safety protection mechanism 1 from a first state to a second state, thereby causing at least some of the battery cells 100 to be electrically connected to the housing assembly 201 in an autonomous and controllable manner, and causing at least some of the battery cells 100 and the housing assembly 201 to form an equipotential body, thereby preventing high-voltage ignition from occurring within the battery pack 200 and timely adjusting the battery pack 200 from an abnormal state to a stably controllable state.

[0084] Furthermore, inside the battery pack 200, at least some of the battery cells 100 are electrically connected to the housing assembly 201, causing a breakdown point to appear, and by switching the high-voltage system within the battery pack 200 to multiple equipotential components, the battery pack 200 can be protected and the safety of the operation of the battery pack 200 can be improved.

[0085] In some embodiments, when the security mechanism 1 is in the second state, the number of battery cells 100 electrically connected to the housing assembly 201 is at least three.

[0086] Here, the structures in which the at least three battery cells 100 are electrically connected to the housing assembly 201 may be the same or may not be completely the same.

[0087] In this embodiment, when the battery pack 200 satisfies a preset trigger condition, the safety protection mechanism 1 is put into a second state, and at least three battery cells 100 are electrically connected to the housing assembly 201, thereby forming at least three breakdown points within the battery pack 200, reducing the voltage division between two breakdown points across the entire high-voltage load and reducing the risk of high-voltage ignition. The battery pack 200 can be timely adjusted from an abnormal state to a stably controllable state, which not only improves the safety of the battery cells 100 within the battery pack 200, but also improves the safety of the control electrical box connected to the battery pack 200.

[0088] In some embodiments, when the safety mechanism 1 is in the second state, all of the battery cells 100 are electrically connected to the housing assembly 201 .

[0089] Here, the structures by which all the battery cells 100 are electrically connected to the housing assembly 201 may be the same, but do not have to be completely the same.

[0090] In this embodiment, when the battery pack 200 satisfies a preset trigger condition, the safety protection mechanism 1 is put into the second state, and all of the battery cells 100 in the battery pack 200 are electrically connected to the housing assembly 201, thereby forming a breakdown point in each of the battery cells 100 in the battery pack 200 and minimizing the voltage division between the two breakdown points of the entire high-voltage load. Even if an abnormality occurs in any one of the battery cells 100, the risk of high-voltage ignition is reduced, and the battery pack 200 can be timely adjusted from an abnormal state to a stably controllable state, which not only improves the safety of the battery cells 100 in the battery pack 200 but also improves the safety of the control electrical box connected to the battery pack 200.

[0091] In some embodiments, the safety protection mechanism 1 includes a plurality of sub-protective members 1', which are arranged in one-to-one correspondence with a plurality of battery cells 100, and each sub-protective member 1' has a first state and a second state, and the sub-protective member 1' is configured to insulate the corresponding battery cell 100 from the housing assembly 201 in the first state, as shown in Figures 5 and 6, and to electrically connect the corresponding battery cell 100 to the housing assembly 201 in the second state, as shown in Figure 8.

[0092] Here, the multiple sub-protective members 1' are structurally independent from one another, and the multiple sub-protective members 1' may be controlled independently from one another or in conjunction with one another. For example, one sub-protective member 1' may be installed for each battery cell 100 in the battery pack 200.

[0093] Alternatively, the sub-protective member 1' can only change unilaterally from the first state to the second state, and cannot return to the first state after reaching the second state.

[0094] Optionally, the sub-protective member 1' may be switched between a first state and a second state. For example, the sub-protective member 1' may be configured to be in the second state and to return to the first state when a preset trigger condition is no longer present. After the safety risk of the battery pack 200 is reduced, the sub-protective member 1' may be automatically returned to the first state. This reduces operational risks when an operator removes a discarded battery pack 200, thereby improving operational safety.

[0095] When all the battery cells 100 in the battery pack 200 are operating normally, the multiple sub-protective members 1' are all in the first state, and all the multiple battery cells 100 in the battery pack 200 are insulated from the housing assembly 201, thereby ensuring the insulation performance when the battery pack 200 is operating normally.

[0096] When thermal runaway or other abnormality occurs in a battery cell 100 in the battery pack 200, a preset trigger condition is met and the battery pack 200 cannot operate normally, and all of the multiple sub-protective members 1' are changed from a first state to a second state, and all of the multiple battery cells 100 in the battery pack 200 on which the sub-protective members 1' are installed are electrically connected to the housing assembly 201.

[0097] Alternatively, if a sub-protective member 1' is installed corresponding to each of the multiple battery cells 100, some of the sub-protective members 1' can be flexibly controlled to be turned on, so that the internal high voltage of the battery pack 200 can be switched to different charging members to meet different needs.

[0098] This embodiment corresponds to installing a plurality of sub-protective members 1' in a one-to-one correspondence with a plurality of battery cells 100 and installing the safety protection mechanism 1 as a plurality of independent sub-protective members 1', which allows for flexible installation of the sub-protective members 1' for a specific number of battery cells 100 located in specific positions, simplifies the structure of the sub-protective members 1', reduces the volume of the sub-protective members 1', and facilitates installation in a compact internal space of the battery pack 200. Furthermore, even if a faulty sub-protective member 1' occurs after the battery pack 200 has operated for a long period of time, the safety protection function can be achieved by relying on the derating of other sub-protective members 1', thereby further improving the operational safety of the battery pack 200.

[0099] In some embodiments, the safety mechanism 1 is now provided between the battery cell 100 and the bottom or top wall of the housing assembly 201 .

[0100] Here, when multiple battery cells 100 are installed in a single layer, providing the safety protection mechanism 1 between the battery cell 100 and the bottom wall or top wall of the housing assembly 201 is advantageous for selectively realizing electrical connection between some or all of the battery cells 100 and the housing assembly 201 when a preset trigger condition is met. When multiple battery cells 100 are installed in two layers, providing the safety protection mechanism 1 between the battery cell 100 and the bottom wall or top wall of the housing assembly 201 is advantageous for selectively realizing electrical connection between some or all of the battery cells 100 in the same layer and the housing assembly 201 when a preset trigger condition is met. If the safety protection mechanism 1 is simultaneously provided between the bottom wall of the housing assembly 201 and the battery cell 100 closest to the bottom wall and between the top wall of the housing assembly 201 and the battery cell 100 closest to the top wall, safety protection for all of the battery cells 100 can be achieved.

[0101] In this embodiment, safety protection for some or all of the battery cells 100 in the same layer can be achieved by simply adding a predetermined space in the height direction of the battery pack 200. This allows the battery pack 200 to have a compact internal space while protecting a larger number of battery cells 100 using a minimum amount of space, thereby improving the operational safety of the battery pack 200.

[0102] 11 , the preset trigger condition includes at least one of the following: the temperature inside the housing assembly 201 reaches a preset temperature; the air pressure inside the housing assembly 201 reaches a preset pressure; the smoke density inside the housing assembly 201 reaches a preset density; and the battery management system 205 of the battery pack 200 emits an electrical signal indicating an abnormality in the battery cell 100. The above conditions may be arbitrarily selected and combined, and the preset trigger condition may be determined to be reached when one of the conditions is satisfied, or when all of the conditions are satisfied.

[0103] Optionally, a status monitoring member 203 is installed within the housing assembly 201, which is configured to detect environmental parameters within the housing assembly 201 to determine whether a preset trigger condition is met, and determine that the preset trigger condition is met when the detection signal exceeds a preset threshold, for example, to detect at least one of the temperature, air pressure, and smoke concentration inside the housing assembly 201.

[0104] For example, the status monitoring member 203 may be a temperature detection member attached to the inner wall of the housing assembly 201 to collect the temperature of the housing assembly 201 or the temperature of the internal region, or attached to the end cap 50 of the battery cell 100 to collect the temperature of the end cap 50. If the temperature inside the housing assembly 201 exceeds a preset temperature, thermal runaway or excessive heat generation may occur inside the battery pack 200, so safety protection needs to be turned on in a timely manner.

[0105] For example, the status monitoring member 203 may be a pressure detection member that is installed inside the housing assembly 201 to collect the air pressure of the housing assembly 201, and if the air pressure inside the housing assembly 201 exceeds a preset pressure, the air pressure inside the housing assembly 201 may not be released in a timely manner due to thermal runaway occurring inside the battery pack 200, so safety protection needs to be turned on in a timely manner.

[0106] For example, the status monitoring member 203 may be a smoke detection member that is installed inside the housing assembly 201 to collect the smoke density of the housing assembly 201; if the smoke density inside the housing assembly 201 exceeds a preset density, thermal runaway may occur inside the battery pack 200, causing sparks or smoke in the battery cell 100 to be ejected into the housing assembly 201; in this case, safety protection needs to be turned on in a timely manner.

[0107] Alternatively, the battery management system 205 may generate an electrical signal indicating an abnormality in the battery cell 100 to determine whether a preset trigger condition is met. The battery management system 205 may acquire a detection signal from the status monitoring component 203 and determine that the preset trigger condition is met if the detection signal exceeds a preset threshold, or may monitor in real time whether the operating electrical signal (including voltage, current, or other parameters) of each battery cell 100 is within a preset parameter range and determine that an abnormality exists in the operation of the battery cell 100 if the preset parameter range is exceeded. In either of these two cases, the battery management system 205 may generate an electrical signal indicating that the battery cell 100 is abnormal.

[0108] Both the signals collected by the status monitoring member 203 and the signals emitted by the battery management system 205 can be received by the controller 204, and the controller 204 is configured to determine whether the signals collected by the monitoring member 203 exceed a predetermined threshold, and when the predetermined threshold is exceeded and / or when the controller 204 receives an electrical signal indicating that the battery cells 100 are abnormal, change the safety protection mechanism 1 to a second state and electrically connect at least some of the battery cells 100 to the housing assembly 201.

[0109] Alternatively, the environment within the housing assembly 201 may directly be the preset trigger condition of the safety protection mechanism 1, and the preset trigger condition is met when an environmental parameter within the housing assembly 201 exceeds a preset threshold. For example, the temperature within the housing assembly 201 reaches a preset temperature, the air pressure within the housing assembly 201 reaches a preset pressure, and / or the smoke density within the housing assembly 201 reaches a preset density.

[0110] This embodiment facilitates accurate determination of the occasion when the safety protection mechanism 1 switches to the second state, making it possible to quantitatively determine whether an abnormality has occurred in the battery pack 200, ensuring safety when an abnormality occurs in the battery pack 200, and preventing the safety protection mechanism 1 from being inadvertently turned on.

[0111] In some embodiments, the safety mechanism 1 is configured to transition from a first state to a second state by mechanical action when a pre-defined trigger condition is met.

[0112] Here, the mechanical operation may be a movement, such as a linear movement or a swinging movement, occurring in a member of the safety protection mechanism 1.

[0113] In this embodiment, when a preset trigger condition is met, the safety protection mechanism 1 can be changed in state by mechanical operation, and the operation is reliable, thereby realizing reliable safety protection of the battery cell 100 and advantageously realizing bidirectional switching between the first state and the second state.

[0114] In some embodiments, as shown in Figures 5 to 9, the safety protection mechanism 1 includes multiple sub-protective members 1' each installed on a different battery cell 100, and each sub-protective member 1' has a first state and a second state. The battery cell 100 includes a housing 100', and the sub-protective members 1' are installed in the housing 100'. When a preset trigger condition is met, the expansion force of the housing 100' generates a mechanical action, causing the sub-protective member 1' to change from the first state to the second state.

[0115] Here, the sub-protective member 1' is provided in the housing 100' of the battery cell 100, and can be deformed by utilizing the expansion force received by the housing 100' to generate mechanical movement in the sub-protective member 1' and drive it to change from a first state to a second state.

[0116] Alternatively, this expansion force can cause the housing 100' to protrude outward, for example, the case 10 or the end cap 50 to protrude outward, or this expansion force can cause the pressure relief member 52 to turn on and open outward, for example, the pressure relief member 52 is an explosion-proof valve, which is still partially connected to the end cap 50 after being turned on, and the remaining part moves outward and opens, generating a mechanical movement in the sub-protective member 1' to change from the first state to the second state.

[0117] Alternatively, this expansion force may be due to expansion occurring during operation of the electrode assembly 30, or due to expansion occurring when thermal runaway occurs in the battery cell 100. Since the largest surface of the battery cell 100 has the largest amount of expansion, the sub-protective member 1' may be provided on the largest surface of the battery cell 100 to ensure its operation, or may be provided on any surface other than the largest surface of the battery cell 100 and still remain within the protection range. For example, in an embodiment in which multiple battery cells 100 are placed flat within the housing assembly 201, i.e., the thickness direction of the electrode assembly 30 of the battery cell 100 coincides with the thickness direction of the battery pack 200, and the surface of the battery cell 100 facing the top wall or bottom wall of the housing assembly 201 is the largest surface, the sub-protective member 1' may be provided on the surface of the battery cell 100 facing the top wall or bottom wall of the housing assembly 201.

[0118] In this embodiment, the safety protection mechanism 1 is installed as a plurality of independent sub-protective members 1', which allows the sub-protective members 1' to be flexibly installed for a specific number of battery cells 100 located in specific positions, simplifies the structure of the sub-protective members 1', reduces the volume of the sub-protective members 1', and facilitates installation in a compact internal space of the battery pack 200. Furthermore, even if a faulty sub-protective member 1' occurs after the battery pack 200 has operated for a long period of time, the safety protection function can be achieved by relying on the derating of other sub-protective members 1', thereby further improving the operational safety of the battery pack 200.

[0119] Furthermore, by providing the sub-protective member 1' in the housing 100', when an abnormality occurs in the battery cell 100, the expansion force generated inside acts on the housing 100', causing the housing 100' to deform, causing a mechanical movement in the sub-protective member 1', changing it from a first state to a second state. This method of triggering the operation of the sub-protective member 1' eliminates the need for a status monitoring member 203, and by directly utilizing the structural change in the battery cell 100 when an abnormality occurs to activate the sub-protective member 1', it simplifies the structure and control method of the safety protection system of the battery pack 200, reduces malfunctions of the sub-protective member 1' due to failure of electronic components, improves the operational reliability of the sub-protective member 1', and thereby improves the operational safety of the battery pack 200.

[0120] In some embodiments, as shown in Figures 5 to 9, the housing 100' is provided with a pressure relief member 52, and the sub-protective member 1' is provided on the pressure relief member 52, and is configured so that the pressure relief member 52 is turned on by receiving an expansion force, thereby generating a mechanical operation and changing from a first state to a second state.

[0121] Here, the specific structure of the pressure relief member 52 has been described in detail above. The pressure relief member 52 may be provided on the case 10 or the end cap 50. In order to facilitate the installation of sub-protective members 1' for more battery cells 100, the sub-protective members 1' may be provided on the surface facing the bottom wall or top wall of the housing assembly 201 of the battery cell 100, and accordingly, the pressure relief member 52 is provided on the surface facing the bottom wall or top wall of the housing assembly 201 of the case 10.

[0122] In this embodiment, the sub-protective member 1' is provided on the pressure relief member 52. When thermal runaway occurs in the battery cell 100 and the internal pressure exceeds a predetermined pressure, the pressure relief member 52 is turned on. After the pressure relief member 52 is turned on, a portion of the structure moves outward and opens. The opening movement of the pressure relief member 52 is relatively large, so that the sub-protective member 1' generates a mechanical movement to reliably drive the sub-protective member 1' to change from the first state to the second state, thereby turning on the sub-protective member 1' in a timely manner and improving the safety of the operation of the battery pack 200.

[0123] In some embodiments, as shown in FIG. 9, the sub-protective member 1′ includes an elastic element 11 and a wrap 12, the elastic element 11 is connected between the housing 100′ and the wrap 12, and when the sub-protective member 1′ is in the second state, the wrap 12 is electrically connected to the housing assembly 201.

[0124] Here, the elastic element 11 may be a spring, and there may be one, two or more elastic elements 11, as long as they can stably support the wrap 12. The wrap 12 may be made of metal material and may have a rectangular, circular or other shaped wrap plate. As shown in FIG. 7, in the first state, the wrap plate may be installed parallel to the surface of the housing 100', and the lengths of all the elastic elements 11 are the same.

[0125] For example, one end of the elastic element 11 is connected to the pressure relief member 52, and the other end of the elastic element 11 is connected to the wrap 12. The pressure relief member 52 may be provided on a surface facing the bottom wall or top wall of the housing assembly 201 of the battery cell 100, and a weakened portion may be provided at the connection point of the pressure relief member 52 with the main body part of the housing 100′. The pressure relief member 52 may have an oval or rectangular shape, and two elastic elements 11 are provided on the pressure relief member 52 along its longitudinal direction at an interval, and the two elastic elements 11 jointly support the wrap 12.

[0126] The operating principle of the sub-protective member 1' shown in FIG. 9 is as follows. When thermal runaway occurs inside the battery cell 100, the weak portion is torn by air pressure, causing one side of the pressure relief member 52 to open outward, thereby acting on the elastic element 11 to move the wrap 12 toward the housing assembly 201 until the wrap 12 is electrically connected to the housing assembly 201. Because the wrap 12, elastic element 11, and pressure relief member 52 are all made of conductive materials, this corresponds to an electrical connection between the battery cell 100 and the housing assembly 201. Since there is no external force to return the pressure relief member 52 to its original position after it opens, the wrap 12 can maintain its electrical connection with the housing assembly 201. For example, the wrap 12 may be electrically connected by contacting the housing assembly 201. Optionally, the elastic element 11 may be installed in a portion of the housing 100' other than the pressure relief member 52.

[0127] In this embodiment, the expansion of the housing 100' of the battery cell 100 is utilized to cause the elastic element 11 to act on the wrap 12, and the elastic action applied by the elastic element 11 to the wrap 12 makes it easier to establish an electrical connection between the wrap 12 and the housing assembly 201, and even if the electrical connection is maintained for a short time, the high voltage of the battery cell 100 can be quickly released, preventing the occurrence of high-voltage ignition and improving the operational safety of the battery pack 200.

[0128] In some embodiments, as shown in Figures 12 and 13A, the safety protection mechanism 1 includes multiple sub-protective members 1' each installed on a different battery cell 100, and each sub-protective member 1' has a first state and a second state, where the sub-protective member 1' includes a conductive portion 13, an insulating portion 14, and a heating portion 15, the conductive portion 13 is connected to the battery cell 100, the insulating portion 14 covers the conductive portion 13, and a gap is formed between the conductive portion 13 and the insulating portion 14, the heating portion 15 is disposed in the gap, and the sub-protective member 1' is configured to be changed from the first state to the second state by the heating portion 15 releasing heat to destroy the insulating portion 14.

[0129] Here, the conductive portion 13 may be connected to the housing 100' of the battery cell 100, for example, to the case 10 or the end cap 50. In FIGS. 12 and 13A, the conductive portion 13 may be connected to the pressure relief member 52 or to the electrode terminal 51. The conductive portion 13 may be manufactured using a metal material and may have a columnar structure protruding from the battery cell 100, for example, a cylindrical structure. The insulating portion 14 may be designed as a tubular structure and inserted outside the conductive portion 13. The insulating portion 14 may completely cover the end of the conductive portion 13 away from the battery cell 100, and the side surfaces of the insulating portion 14 and the conductive portion 13 may be in contact with each other or may have a gap. For example, there may be a gap between the side surface of the insulating portion 14 and the side surface of the conductive portion 13, and the end surface of the insulating portion 14 may be in contact with the end surface of the conductive portion 13. The insulating portion 14 may be manufactured using any insulating material.

[0130] When the battery cell 100 operates normally, the end face of the insulating part 14 facing away from the battery cell 100 contacts the housing assembly 201, and the heating part 15 does not emit heat. When a preset trigger condition is met, the heating part 15 emits heat to destroy the insulating part 14, causing the insulating part 14 to melt or split using the heat, thereby bringing the end face of the conductive part 13 facing away from the battery cell 100 into direct contact with the housing assembly 201, thereby achieving an electrical connection between the conductive part 13 and the housing assembly 201. To achieve this goal, the thickness of the insulating part 14 is made very thin.

[0131] In this embodiment, when a preset trigger condition is met, the heat emitted by the heating unit 15 is used to destroy the insulating unit 14, thereby establishing an electrical connection between the conductive unit 13 and the housing assembly 201. The heat generated by the heating unit 15 is greater than the melting point of the insulating unit 14, and a structure in which the heat emission is used to change the sub-protective member 1' from the first state to the second state does not require the installation of a complex movement mechanism within the housing assembly 201, thereby reducing the complexity of the structure, ensuring the insulating performance of the sub-protective member 1' in the first state, and improving the reliability of the sub-protective member 1' switching to the second state, thereby improving the operational safety of the battery pack 200.

[0132] In some embodiments, as shown in FIG. 13A, the heating portion 15 includes a coil 15A configured to be energized when a preset trigger condition is met, generating a magnetic field to heat and destroy the insulating portion 14.

[0133] Here, the coil 15A may be extrapolated outside the heating unit 15, and the controller 204 can pass an alternating current through it to generate a magnetic field, which releases heat and destroys the insulating unit 14. On the other hand, if an abnormal event such as thermal runaway occurs in the battery cell 100, the generated heat is transferred to the insulating unit 14 via the conductive unit 13, promoting the destruction of the insulating unit 14.

[0134] In this embodiment, when a preset trigger condition is met, the coils 15A in the multiple sub-protective elements 1' are spontaneously energized, and the current in the coils 15A is used to generate a magnetic field and release heat, which can then be used to destroy the insulating element 14. This method allows the amount of heat released to be flexibly controlled, ensuring the removal of the insulating element 14, thereby ensuring the sub-protective elements 1' are turned on when an abnormality occurs in the operation of the battery pack 200. Furthermore, this embodiment allows the controller 204 to more accurately determine the occasion for turning on the safety protection mechanism 1 and spontaneously control the multiple sub-protective elements 1' to be turned on, which is advantageous for realizing the synchronized turning on of multiple sub-protective elements 1'.

[0135] In some embodiments, as shown in FIG. 13B , the insulating portion 14 divides the gap between the conductive portion 13 and the insulating portion 14 into a first cavity 16 and a second cavity 17, the first cavities 16 of each of the multiple sub-protective members 1′ are connected to each other and contain an oxidizing agent 15B, the second cavities 17 of each of the multiple sub-protective members 1′ are connected to each other and contain a reducing agent 15C, the heating portion 15 contains the oxidizing agent 15B and the reducing agent 15C, and when a predetermined trigger condition is met, the conductive portion 13 is heated to cause the oxidizing agent 15B and the reducing agent 15C to react with each other, and the heat released by the reaction destroys the insulating portion 14.

[0136] Here, although only the structure of a single sub-protective member 1' is visible in Figure 13B, there are multiple sub-protective members 1' installed in parallel in the front-to-back direction of this schematic diagram, and the first cavity 16 and the second cavity 17 extend until they are flush with the side of the battery cell 100, so that the first cavities 16 of each of the multiple sub-protective members 1' are connected to each other, and the second cavities 17 of each of the multiple sub-protective members 1' are connected to each other.

[0137] In this embodiment, if a preset trigger condition is met, heat generated when an abnormality occurs in a specific battery cell 100 can be transferred to the corresponding conductive part 13, and the conductive part 13 melts the part of the insulating part 14 located between the first cavity 16 and the second cavity 17. The oxidizing agent 15B and the reducing agent 15C then undergo a chemical reaction, releasing heat. The released heat is used to destroy the insulating part 14, and at the same time, this heat melts the insulating part 14 located between the first cavity 16 and the second cavity 17 in the sub-protective member 1' corresponding to another battery cell 100, causing the oxidizing agent 15B and the reducing agent 15C to react sequentially along the arrangement path of the multiple battery cells 100, destroying all of the insulating parts 14 in the multiple sub-protective members 1'. This ensures that the multiple sub-protective members 1' are turned on when an abnormality occurs in the operation of the battery pack 200. In this embodiment, the sub-protective member 1' can be passively turned on by utilizing the heat generated when an abnormality occurs in the battery cell 100, and the safety protection mechanism 1 can be turned on more timely and quickly.

[0138] In some embodiments, the battery pack 200 further includes a controller 204 configured to, when receiving a signal that satisfies a preset trigger condition, issue an activation signal to the safety protection mechanism 1, causing the safety protection mechanism 1 to change from the first state to the second state.

[0139] Here, the controller 204 can receive a monitoring signal from the state monitoring member 203 and determine that a preset trigger condition is met when it determines that the detection signal exceeds a preset threshold, or can receive a signal indicating an abnormality in the battery cell 100 issued by the battery management system 205 and determine that the preset trigger condition is met in this case. When the preset trigger condition is met, the controller 204 changes the safety protection mechanism 1 from the first state to the second state by automatically issuing an activation signal to the safety protection mechanism 1. Specifically, the controller 204 can change all of the multiple sub-protection members 1' to the second state by simultaneously or separately issuing activation signals to the multiple sub-protection members 1'.

[0140] In this embodiment, when an abnormality occurs in the operation of battery pack 200, controller 204 automatically controls safety protection mechanism 1 to be turned on, and controller 204 can comprehensively evaluate the received signals, for example, only when the detection signal exceeds a predetermined threshold for a predetermined period of time can it be determined that a predetermined trigger condition is met, thereby preventing accidental deviation of the collected signals of status monitoring member 203, more accurately determining when to turn on safety protection mechanism 1, and preventing battery pack 200 from being discarded due to erroneous activation of safety protection mechanism 1. Furthermore, the automatic control method can also cause controller 204 to take other safety protection measures after safety protection mechanism 1 is turned on, such as powering off or cooling battery pack 200, or automatically turning on a pressure relief member on housing assembly 201.

[0141] In some embodiments, the security mechanism 1 is configured to change from the first state to the second state directly upon the action of a preset trigger condition.

[0142] Here, the state of the safety protection mechanism 1 is changed directly by the influence of the environment within the housing assembly 201, for example, the state of the safety protection mechanism 1 can be changed by the influence of pressure, temperature or smoke within the housing assembly 201.

[0143] In this embodiment, when an abnormality occurs in the operation of battery pack 200, there is no need for controller 204 to determine the environmental change and then issue an ON signal to safety protection mechanism 1. Instead, safety protection mechanism 1 is passively turned on by directly relying on the environmental change of housing assembly 201, so that safety protection mechanism 1 can be turned on more timely and quickly. When battery pack 200 enters a runaway state, an equipotential body is quickly formed between battery cell 100 and housing assembly 201, multiple breakdown points are formed within battery pack 200, and the voltage division at the two breakdown points of the entire high-voltage load can be reduced, preventing instantaneous high-voltage ignition. Battery pack 200 can be timely adjusted from an abnormal state to a stable, controllable state, and further deterioration can be avoided.

[0144] In some embodiments, the battery cell 100 includes a housing 100', and the safety mechanism 1 is configured to electrically connect the housing 100' with the housing assembly 201 when in the second state.

[0145] If an abnormality occurs in the battery pack 200, the temperature inside the housing assembly 201 rises, and since the insulating layer 20 covering the housing 100' of the battery cell 100 has a relatively low melting point, the insulating layer 20 melts, and the safety protection mechanism 1 operates to electrically connect the housing 100' to the housing assembly 201. Alternatively, the safety protection mechanism 1 can operate to destroy the insulating layer 20, thereby electrically connecting the housing 100' to the housing assembly 201.

[0146] In this embodiment, if an abnormality occurs in the operation of the battery pack 200, the housing 100' is electrically connected to the housing assembly 201, and since the housing 100' has a relatively large surface area, it is easy to install the safety protection mechanism 1, ensures reliable operation of the safety protection mechanism 1, and is located away from the electrical connection parts of the battery cells 100, preventing the operation of the safety protection mechanism 1 from affecting the electrical connection parts. Furthermore, since the battery cells 100 are covered by the insulating layer 20 when the battery pack 200 is operating normally, the insulation performance between the battery cells 100 and the housing assembly 201 can be reliably guaranteed when the safety protection mechanism 1 is installed.

[0147] In some embodiments, as shown in Figures 14 to 16, the battery cell 100 includes a housing 100', and the housing 100' is provided with electrode terminals 51, and the battery pack 200 further includes a bus bar member 202 configured to electrically connect the electrode terminals 51 of two of the battery cells 100, and wherein the safety protection mechanism 1 is configured to electrically connect at least one of the electrode terminals 51 and the bus bar member 202 to the housing assembly 201 when in the second state.

[0148] Here, the electrode terminals 51 may be attached toward the top wall of the housing assembly 201, and the busbar members 202 may connect the electrode terminals 51 of two adjacent battery cells 100, thereby realizing a series connection, a parallel connection, or a series-parallel connection of the multiple battery cells 100. The safety protection mechanism 1 may be provided on the housing assembly 201, the electrode terminals 51, or the busbar members 202, and electrically connects at least one of the electrode terminals 51 and the busbar members 202 to the housing assembly 201 when a preset trigger condition is satisfied. When the battery pack 200 operates normally, the busbar members 202 may be covered with an insulating layer, and when an abnormality occurs in the battery pack 200 and the temperature inside the housing assembly 201 rises, the insulating layer on the busbar members 202 can be melted, thereby realizing an electrical connection between the busbar members 202 and the housing assembly 201.

[0149] In this embodiment, if an abnormality occurs in the battery pack 200, the safety protection mechanism 1 operates to electrically connect at least one of the electrode terminals 51 and the bus bar members 202 to the housing assembly 201, and the multiple battery cells 100 in the battery pack 200 are electrically connected via the bus bar members 202. Therefore, by simply installing at least one sub-protection member 1' for the multiple battery cells 100 that are electrically connected, safety protection for the multiple electrically connected battery cells 100 can be achieved, the number of sub-protection members 1' can be reduced, the structure of the safety protection mechanism 1 can be simplified, the space occupied by the safety protection mechanism 1 within the housing assembly 201 can be reduced, and the energy density of the battery pack 200 can be improved.

[0150] In some embodiments, as shown in FIGS. 14 to 16 , the plurality of battery cells 100 are divided into a plurality of battery modules 200′, and the plurality of battery cells 100 in each battery module 200′ are connected in series, parallel, or series-parallel via bus bar members 202, and the safety protection mechanism 1 includes a plurality of conductive members 18, and each battery module 200′ is provided with at least one conductive member 18, one end of which is connected to an electrode terminal 51 that is not connected to the bus bar member 202, and the conductive member 18 is connected to the electrode terminal 51 that is not connected to the bus bar member 202, and the exterior of the conductive member 18 is covered with an insulating layer, and is configured to be electrically connected to the housing assembly 201 after the insulating layer is broken, thereby changing from a first state to a second state.

[0151] Here, a plurality of beams 201C are provided within the housing 201A of the housing assembly 201, and the plurality of beams 201C divide the internal area of ​​the housing 201A into a plurality of accommodating cavities 201D. For example, the plurality of beams 201C may be installed parallel or vertically, and a plurality of battery cells 100 are provided within each accommodating cavity 201D, and are connected in series, parallel, or series-parallel to form a battery module 200'.

[0152] The conductive member 18 corresponds to the sub-protective member 1′ and may have a thin plate or sheet-like structure, and may be designed as a rectangle or other elongated shape. The conductive member 18 may adopt the same structure as the bus bar member 202 to reduce the number of parts. For the same battery module 200′, the electrode terminals 51 of multiple battery cells 100 are electrically connected via the bus bar member 202. Generally, the electrode terminals 51 of the battery cells 100 located at the outermost sides of the electrical connection path are not connected to the bus bar member 202. The conductive member 18 may be connected to the electrode terminals 51 that are not connected to the bus bar member 202 and are closer to the housing assembly 201. When a preset trigger condition is met, the bus bar member 202 can be easily electrically connected to the housing assembly 201.

[0153] Optionally, in the first state, the exterior of the conductive member 18 is covered with an insulating layer, and the conductive member 18 abuts against the housing assembly 201 while maintaining insulation. If a thermal runaway or other abnormality occurs in the battery pack 200, if a preset trigger condition is met, the temperature inside the housing assembly 201 may be relatively high and exceed the melting point of the insulating layer, causing the insulating layer to melt or break, and the conductive member 18 and the housing assembly 201 to come into direct contact and be electrically connected. For example, the conductive member 18 may abut against the top wall or bottom wall of the housing assembly 201, or the conductive member 18 may abut against a side wall of the housing assembly 201 via its end.

[0154] Optionally, the housing assembly 201 includes a housing 201A and two lids 201B, the housing 201A has two opposing openings, and the two lids 201B seal the two openings, respectively.

[0155] In this embodiment, the safety protection mechanism 1 is configured as a plurality of conductive members 18, which are used to be electrically connected to the housing assembly 201 when a preset trigger condition is met, thereby enabling the plurality of battery cells 100 in the battery module 200′ to be electrically connected to the housing assembly 201, reducing the number of conductive members 18 and simplifying the structure of the safety protection mechanism 1, reducing the space occupied by the safety protection mechanism 1 in the housing assembly 201, and improving the energy density of the battery pack 200.

[0156] Next, the present application provides a safety control method for the battery pack 200, and in some embodiments, as shown in FIG. 17, the safety control method includes:

[0157] S110: The safety protection mechanism 1 in the housing assembly 201 of the battery pack 200 is set to a first state, thereby isolating the plurality of battery cells 100 in the housing assembly 201 from the housing assembly 201.

[0158] S120, if a preset trigger condition is met, change the safety protection mechanism 1 from a first state to a second state, so as to electrically connect at least some of the battery cells 100 with the housing assembly 201;

[0159] In this embodiment, when an abnormal battery cell 100 is detected and a preset trigger condition is met, the battery pack 200 can change the safety protection mechanism 1 from a first state to a second state, thereby causing at least some of the battery cells 100 to be electrically connected to the housing assembly 201 in an autonomous and controllable manner, and causing at least some of the battery cells 100 and the housing assembly 201 to form an equipotential body, thereby preventing high-voltage ignition from occurring within the battery pack 200 and timely adjusting the battery pack 200 from an abnormal state to a stably controllable state.

[0160] Furthermore, inside the battery pack 200, at least some of the battery cells 100 are electrically connected to the housing assembly 201, causing a breakdown point to appear, and by switching the high-voltage system within the battery pack 200 to multiple equipotential components, the battery pack 200 can be protected and the safety of the operation of the battery pack 200 can be improved.

[0161] In some embodiments, changing the safety mechanism 1 from the first state to the second state in S120 when a preset trigger condition is met includes: When the controller 204 receives a signal that satisfies a preset trigger condition, the controller 204 issues an activation signal to the safety protection mechanism 1, causing the safety protection mechanism 1 to change from the first state to the second state.

[0162] In this embodiment, when an abnormality occurs in the operation of battery pack 200, controller 204 automatically controls safety protection mechanism 1 to be turned on, and controller 204 can comprehensively evaluate the received signals, for example, only when the detection signal exceeds a predetermined threshold for a predetermined period of time can it be determined that a predetermined trigger condition is met, thereby preventing accidental deviation of the collected signals of status monitoring member 203, more accurately determining when to turn on safety protection mechanism 1, and preventing battery pack 200 from being discarded due to erroneous activation of safety protection mechanism 1. Furthermore, the automatic control method can also cause controller 204 to take other safety protection measures after safety protection mechanism 1 is turned on, such as powering off or cooling battery pack 200, or automatically turning on a pressure relief member on housing assembly 201.

[0163] The controller 204 described in this disclosure may be a general-purpose processor, a programmable logic controller (abbreviated as PLC), a digital signal processor (abbreviated as DSP), an application specific integrated circuit (abbreviated as ASIC), a field-programmable gate array (abbreviated as FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware assembly, or any suitable combination thereof for performing the functions described in this disclosure.

[0164] The present application also provides a safety control device for the battery pack 200, which includes a memory for storing instructions and a processor for executing the instructions to cause the safety control device to execute and realize the safety control method for the battery pack 200 described in the above embodiments.

[0165] 18 is a structural schematic diagram of some embodiments of the safety control device of the battery pack 200 of the present application. The computer device includes a memory 401 and a processor 402.

[0166] The memory 401 is used to store instructions, and the processor 402 is coupled to the memory 401, and the processor 402 is configured to execute and realize the methods related to the above embodiments based on the instructions stored in the memory.

[0167] 18, the computer device further includes a communication interface 403 for information interaction with other devices. At the same time, the computer device includes a bus 404, a processor 402, the communication interface 403, and a memory 401, and completes communication between them via the bus 404.

[0168] The memory 401 may include a high-speed RAM memory and may further include a non-volatile memory, such as at least one magnetic disk memory. The memory 401 may be a memory array. The memory 401 may be divided into blocks, and the blocks may be combined into virtual volumes according to certain rules.

[0169] It should be noted that the processor 402 may be a central processor CPU, or may be an application specific integrated circuit ASIC, or may be configured in one or more integrated circuits that implement embodiments of the present application.

[0170] In addition, the present application further provides a computer-readable storage medium, in which computer instructions are stored, and when the instructions are executed by a processor, the safety control method for the battery pack 200 described in the above embodiment is realized.

[0171] In some other embodiments, a computer-readable storage medium stores computer program instructions, which, when executed by a processor, implement the steps of the safety control method in the above embodiments. As will be apparent to those skilled in the art, the embodiments of the present application may be provided as a method, an apparatus, or a computer program product. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. The present application may also take the form of a computer program product embodied in one or more computer-usable non-transitory storage media (including, but not limited to, magnetic disk memory, CD-ROM, optical memory, etc.) containing computer-usable program code.

[0172] The present application has been described with reference to flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and combinations of flows and / or blocks in the flowcharts and / or block diagrams, may be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to create a machine, whereby the instructions, executed by the processor of the computer or other programmable data processing device, create an apparatus for implementing the functions specified in one or more flows in the flowcharts and / or one or more blocks in the block diagrams.

[0173] These computer program instructions may be stored in a computer-readable memory that causes a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture that includes an instruction apparatus that implements the functions specified in one or more flows of the flowcharts and / or one or more blocks of the block diagrams.

[0174] These computer program instructions may be loaded into a computer or other programmable data processing device, thereby causing the computer or other programmable apparatus to perform a series of operational steps to generate a computer-implemented process, such that the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in one or more flows of the flowcharts and / or one or more blocks of the block diagrams.

[0175] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and equivalents may be substituted for the components therein without departing from the scope of the present application. In particular, unless there is a structural conflict, the technical features recited in each embodiment may be combined in any manner. The present application is not limited to the specific embodiments disclosed in the specification, but includes all technical solutions falling within the scope of the claims. [Explanation of symbols]

[0176] 1 Safety protection mechanism 1' Sub-protective member 11 Elastic element 12 laps 13 Conductive part 14 Insulation section 15 Heating section 15A coil 15B Oxidizer 15C reducing agent 16 First Cavity 17 Second Cavity 18 Conductive material 100 battery cells 100' Housing 10 cases 101 Aperture 20 insulating layer 30 Electrode Assembly 30' Tab 40 adapter 50 End Cap 51 Electrode terminal 52 Pressure relief member 200 battery packs 200' battery module 201 Housing Assembly 201A housing 201B Lid body 201C Beam 201D Storage Cavity 202 Busbar components 203 Condition monitoring components 204 Controller 205 Battery Management System 300 vehicles 301 axle 302 wheels 303 Motor 304 Controller 401 memory 402 processor 403 Communication Interface 404 Bus

Claims

1. A battery pack (200), a housing assembly (201); a plurality of battery cells (100) disposed within the housing assembly (201); a safety protection mechanism (1) disposed within the housing assembly (201), the safety protection mechanism having a first state and a second state, wherein when the safety protection mechanism (1) is in the first state, the plurality of battery cells (100) are insulated from the housing assembly (201), and when a preset trigger condition is satisfied, the safety protection mechanism (1) is in the second state, and when the safety protection mechanism (1) is in the second state, at least some of the battery cells (100) are electrically connected to the housing assembly (201); The battery pack (200) includes a housing (100'), and the safety protection mechanism (1) is configured to electrically connect the housing (100') with the housing assembly (201) when in the second state.

2. 2. The battery pack (200) of claim 1, wherein when the safety protection mechanism (1) is in the second state, the number of the battery cells (100) electrically connected to the housing assembly (201) is at least three.

3. 2. The battery pack (200) of claim 1, wherein when the safety protection mechanism (1) is in the second state, all of the battery cells (100) are electrically connected to the housing assembly (201).

4. The battery pack (200) according to any one of claims 1 to 3, wherein the safety protection mechanism (1) includes a plurality of sub-protective members (1'), each of which is installed in one-to-one correspondence with a plurality of the battery cells (100), and each of the sub-protective members (1') has the first state and the second state, and the sub-protective member (1') is configured to insulate the corresponding battery cell (100) from the housing assembly (201) in the first state and to electrically connect the corresponding battery cell (100) to the housing assembly (201) in the second state.

5. The battery pack (200) according to any one of claims 1 to 3, wherein the safety protection mechanism (1) is provided between the battery cell (100) and a bottom wall or a top wall of the housing assembly (201).

6. The battery pack (200) of any one of claims 1 to 3, wherein the predetermined trigger condition includes at least one of the following: the temperature inside the housing assembly (201) reaches a predetermined temperature; the air pressure inside the housing assembly (201) reaches a predetermined pressure; the smoke density inside the housing assembly (201) reaches a predetermined density; and a battery management system (205) of the battery pack (200) emitting an electrical signal indicating an abnormality in a battery cell (100).

7. 4. The battery pack (200) of claim 1, wherein the safety protection mechanism (1) is configured to transition from the first state to the second state by a mechanical action when the preset trigger condition is met.

8. The safety protection mechanism (1) includes a plurality of sub-protective members (1') each installed on a different battery cell (100), and each of the sub-protective members (1') has the first state and the second state; Here, the sub-protective member (1') is provided in the housing (100'), and the sub-protective member (1') is configured to change from the first state to the second state by generating a mechanical action due to the expansion force of the housing (100') when the predetermined trigger condition is satisfied, a battery pack (200) as described in any one of claims 1 to 3.

9. The battery pack (200) according to claim 8, wherein the housing (100') is provided with a pressure relief member (52), the sub-protective member (1') is provided on the pressure relief member (52), and the pressure relief member (52) is configured to generate mechanical action and change from the first state to the second state when it receives an expansion force and turns on.

10. The battery pack (200) of claim 8, wherein the sub-protective member (1') includes an elastic element (11) and a wrap (12), the elastic element (11) is connected between the housing (100') and the wrap (12), and when the sub-protective member (1') is in the second state, the wrap (12) is electrically connected to the housing assembly (201).

11. The safety protection mechanism (1) includes a plurality of sub-protective members (1') each installed on a different battery cell (100), and each of the sub-protective members (1') has the first state and the second state; Here, the sub-protective member (1') includes a conductive portion (13), an insulating portion (14), and a heating portion (15), the conductive portion (13) is connected to the battery cell (100), the insulating portion (14) covers the conductive portion (13), and a gap is formed between the conductive portion (13) and the insulating portion (14), the heating portion (15) is provided in the gap, and the sub-protective member (1') is configured to be changed from the first state to the second state by the heating portion (15) releasing heat and destroying the insulating portion (14).

12. The battery pack (200) according to claim 11, wherein the heating section (15) includes a coil (15A) configured to be energized when a preset trigger condition is satisfied, thereby generating a magnetic field to heat and destroy the insulating section (14).

13. The insulating portion (14) divides the gap between the conductive portion (13) and the insulating portion (14) into a first cavity (16) and a second cavity (17), the first cavities (16) of each of the plurality of sub-protective members (1') communicate with each other and contain an oxidizing agent (15B), and the second cavities (17) of each of the plurality of sub-protective members (1') communicate with each other and contain a reducing agent (15C), 12. The battery pack (200) according to claim 11, wherein the heating section (15) includes the oxidizing agent (15B) and the reducing agent (15C), and is configured to react the oxidizing agent (15B) with the reducing agent (15C) by heating the conductive section (13) when a preset trigger condition is satisfied, and to destroy the insulating section (14) by heat released by the reaction.

14. 4. The battery pack (200) of claim 1, further comprising a controller (204) configured to, when receiving a signal that satisfies a preset trigger condition, issue an activation signal to the safety protection mechanism (1) to change the safety protection mechanism (1) from the first state to the second state.

15. 4. The battery pack (200) according to claim 1, wherein the safety protection mechanism (1) is configured to change from the first state to the second state directly upon the action of the preset trigger condition.

16. The housing (100') is provided with electrode terminals (51), and the battery pack (200) further includes busbar members (202) configured to electrically connect the electrode terminals (51) of each of the two battery cells (100), Here, the safety protection mechanism (1) is configured to electrically connect at least one of the electrode terminal (51) and the busbar member (202) to the housing assembly (201) when in the second state.

17. 17. The battery pack according to claim 16, wherein the plurality of battery cells are divided into a plurality of battery modules, and the plurality of battery cells in each of the battery modules are connected in series, parallel, or series-parallel via the bus bar members. The safety protection mechanism includes a plurality of conductive members, and at least one of the conductive members is installed in each of the battery modules, and the conductive member is connected to the electrode terminal that is not connected to the bus bar member. The exterior of the conductive member is covered with an insulating layer, and the conductive member is configured to be electrically connected to the housing assembly after the insulating layer is broken, thereby changing from the first state to the second state.

18. A power consuming device, comprising a battery pack (200) according to any one of claims 1 to 3, said battery pack (200) being used to provide electrical energy to said power consuming device.

19. A safety control method for a battery pack (200), comprising: a safety protection mechanism (1) in a housing assembly (201) of the battery pack (200) in a first state, thereby isolating a plurality of battery cells (100) in the housing assembly (201) from the housing assembly (201); and changing the safety protection mechanism (1) from the first state to a second state so as to electrically connect the housings (100') of at least some of the battery cells (100) with the housing assembly (201) when a preset trigger condition is satisfied.

20. changing the safety mechanism (1) from the first state to the second state when the preset trigger condition is satisfied; 20. The safety control method for a battery pack (200) according to claim 19, further comprising: when a controller (204) receives a signal that satisfies a preset trigger condition, issuing an activation signal to the safety protection mechanism (1) by the controller (204), thereby changing the safety protection mechanism (1) from the first state to the second state.

Images