Battery cell assembly, battery pack and electric equipment

Abstract

The embodiment of the utility model provides a battery cell assembly, a battery pack and electric equipment, and relates to the technical field of energy storage. The battery cell assembly comprises a cover plate and an alarm device, the cover plate is provided with a pole, the pole comprises a protector, a battery cell is connected with an external port through the protector to form a current path, and when the protector meets a disconnection condition, the current path is disconnected; the off condition includes at least one of a current exceeding a first threshold and a temperature exceeding a second threshold. The alarm device is connected with the protector and gives an alarm when the temperature exceeds a third threshold value, and the third threshold value is smaller than the second threshold value. According to the embodiment of the invention, prompting and alarming can be carried out and the external circuit can be timely disconnected under the condition of short circuit or overheating in the battery cell, so that the safety of the battery pack is improved.

Description

Technical Field

[0001] Embodiments of the present application relate to the technical field of energy storage, and in particular, to a cell assembly, a battery pack, and an electrical device. Background Art

[0002] With the rapid development of economy and technology, battery packs are more and more widely used. A battery pack is a power source that provides power for electrical devices (such as electric vehicles, electric trains, electric bicycles, golf carts, etc.), and its safety performance is crucial.

[0003] A battery pack usually has multiple cells, and the positive and negative electrodes of each cell are conducted through aluminum bars connected by welding. During the operation of the cells, heat is often generated and the temperature rises, and even overcurrent or short circuit may occur. Long-term high temperature will make the cells prone to spraying valves or catching fire, and the safety protection performance of the battery pack is relatively low. Utility Model Content

[0004] Embodiments of the present application provide a cell assembly, a battery pack, and an electrical device to improve the safety protection performance of the battery pack and the electrical device.

[0005] Embodiments of the present application provide the following technical solutions:

[0006] In a first aspect of embodiments of the present application, a cell assembly is provided, including: a cover plate and an alarm device. The cover plate has a terminal post, and the terminal post includes a protector. The cell is connected to an external port through the protector to form a current path. When the protector meets the disconnection condition, the current path is disconnected; the disconnection condition includes at least one of the current exceeding a first threshold and the temperature exceeding a second threshold;

[0007] The alarm device is connected to the protector, and the alarm device gives an alarm when the temperature exceeds a third threshold, and the third threshold is less than the second threshold.

[0008] In a possible implementation manner, the alarm device includes a temperature sensor, a normally open temperature control switch, and an alarm connected in series. When the temperature exceeds the third threshold, the normally open temperature control switch closes and the alarm gives an alarm.

[0009] In a possible implementation manner, the cover plate includes a positive cover plate and a negative cover plate. Both the positive cover plate and the negative cover plate include a cover plate body and the terminal post provided in the cover plate body;

[0010] The alarm device is provided on the cover plate body of the positive cover plate and / or the negative cover plate.

[0011] In a possible implementation manner, the cover plate body of the positive cover plate and the negative cover plate further includes a fireproof layer.

[0012] In a possible implementation, the second threshold is 55 °C and the third threshold is 40 °C.

[0013] In a possible implementation, the cover body includes a cover surface layer, an insulating layer provided on one side of the cover surface layer, and a lead-out layer provided on the side of the insulating layer away from the cover surface layer;

[0014] Through holes are provided in the cover surface layer, the insulating layer, and the lead-out layer, the pole column is provided in the through holes, and the protector is communicated with the lead-out layer.

[0015] In a possible implementation, the pole column further includes a connecting portion and a pole column cover;

[0016] The connecting portion is provided on the side of the protector adjacent to the lead-out layer and abuts against the lead-out layer, and a part of the connecting portion also extends into the through hole of the lead-out layer. The pole column cover is provided on the side of the protector away from the connecting portion to form the external port.

[0017] In a possible implementation, the end face of the connecting portion (22) facing the pole column cover (23) includes a first central region and a first edge region surrounding the first central region, and the protector (21) is opposite to the first central region of the connecting portion (22); and / or,

[0018] [[ID=--]]The end face of the pole column cover (23) facing the connecting portion (22) includes a second central region and a second edge region surrounding the second central region, and the protector (21) is opposite to the second central region of the pole column cover (23).

[0019] In a possible implementation, the pole column further includes a protection ring, and the protection ring is sleeved on the protector;

[0020] Both ends of the protection ring are in contact with the connecting portion and the pole column cover respectively.

[0021] In a possible implementation, the cover further includes an isolation ring, a gasket, and a sealing ring, and the isolation ring, the gasket, and the sealing ring are all sleeved on the pole column;

[0022] The gasket is provided on the cover body, the sealing ring is provided between the pole column and the gasket, and the isolation ring is provided on the side of the gasket away from the cover body and abuts against the pole column cover.

[0023] A second aspect of the embodiments of the present application provides a battery pack, including a housing, a battery cell disposed in the housing, and the battery cell assembly as described above that is buckled on the housing.

[0024] A third aspect of the embodiments of the present application provides an electrical device, including the battery pack as described above.

[0025] In the battery cell assembly, battery pack, and electrical device provided by the embodiments of the present application, the electrode cover plate has a pole column. The pole column includes a protector. The protector is connected to the battery cell and to an external port to form a current path, and disconnects the current path when the current exceeds a first threshold and / or the temperature exceeds a second threshold. An alarm device is connected to the protector. The alarm device gives an alarm when the temperature exceeds a third threshold, and the third threshold is less than the second threshold. By providing the protector and the alarm device, it is possible to give a prompt alarm when the temperature exceeds the third threshold in the case of an internal short circuit or overheat of the battery cell, and to disconnect from the external circuit in time when the current exceeds the first threshold and / or the temperature exceeds the second threshold, improving the safety of the battery pack and the electrical device.

[0026] In addition to the technical problems solved by the embodiments of the present application described above, the technical features constituting the technical solutions, and the beneficial effects brought by these technical features of the technical solutions, other technical problems that can be solved by the battery cover plate, battery pack, and electrical device provided by the embodiments of the present application, other technical features included in the technical solutions, and the beneficial effects brought by these technical features will be further described in detail in the specific implementation manners. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a circuit connection diagram of the battery cell assembly and the battery cell provided by the embodiments of the present application;

[0029] Figure 2 It is another circuit connection diagram of the battery cell assembly and the battery cell provided by the embodiments of the present application;

[0030] Figure 3 It is an exploded view of the positive electrode cover plate provided by the embodiments of the present application;

[0031] Figure 4 It is a schematic diagram of the housing and the battery cell provided by the embodiments of the present application;

[0032] Figure 5Cross-sectional view of the positive electrode cover plate provided by the embodiment of the present application;

[0033] Figure 6 Exploded view of the negative electrode cover plate provided by the embodiment of the present application;

[0034] Figure 7 Cross-sectional view of the negative electrode cover plate provided by the embodiment of the present application.

[0035] Explanation of reference numerals:

[0036] 10 - battery cell; 20 - terminal post;

[0037] 21 - protector; 22 - connecting part;

[0038] 23 - terminal post cover; 24 - protection ring;

[0039] 30 - alarm device; 31 - connecting wire;

[0040] 41 - cover plate surface layer; 42 - insulating layer;

[0041] 43 - lead-out layer; 44 - fireproof layer;

[0042] 45 - explosion-proof valve; 46 - explosion-proof valve protection piece;

[0043] 51 - isolation ring; 52 - gasket;

[0044] 53 - sealing ring; 60 - housing. Detailed implementation manners

[0045] As in the background art, the safety protection performance of the battery pack in the related art is relatively low. Through research, it is found that the reason is as follows: Multiple battery cells are often connected in series through aluminum bars. The existing aluminum bars are usually of an integral aluminum plate structure, and the current-carrying capacity at each place is similar. When an abnormal situation occurs in the battery pack, such as an overcurrent or short circuit of a single battery cell, on the one hand, it is difficult to quickly disconnect the connection with adjacent battery cells, so that all the battery cells in the entire battery pack are at risk of overcurrent or short circuit, and the battery pack is prone to thermal diffusion; on the other hand, there is a lack of detection and alarm for the temperature inside the battery pack, and it is difficult to give a prompt in time, so the safety protection performance of the battery pack is relatively low.

[0046] In view of the above technical problems, an embodiment of the present application provides a battery cover plate, a battery pack and an electrical device, which includes a cover plate and an alarm device. The cover plate has a pole column, and the pole column includes a protector. The protector is connected to the battery cell and an external port to form a current path, and disconnects the current path when the current exceeds a first threshold and / or the temperature exceeds a second threshold. The alarm device is connected to the protector, and the alarm device gives an alarm when the temperature exceeds a third threshold. By providing the protector and the alarm device, it is possible to give a prompt alarm and disconnect from the external circuit in time in case of internal short circuit or overheating of the battery cell, thereby improving the safety of the battery pack and the electrical device.

[0047] In order to make the above objects, features and advantages of the embodiments of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0048] An embodiment of the present application provides an electrical device, which can be a television, an electronic watch, an e-book, a desktop computer, a laptop computer, a tablet computer, a mobile phone, an AR device (Augmented Reality), a VR device (Virtual Reality), etc., or can also be a known electrical device such as an electric vehicle, an electric ship, an electric tool, etc. The present application does not make specific limitations thereto.

[0049] The electrical device includes a battery pack. A battery pack refers to a device that can convert chemical energy into electrical energy and provides electrical energy for the electrical device. The battery pack can be a polymer battery pack. For example, the battery pack can be a lithium-ion power battery pack, which has advantages such as high energy density, low self-discharge, and good discharge performance. The battery pack can also be a sodium-ion battery pack or a sodium-lithium-ion battery pack.

[0050] Referring to Figures 1 to 7 , the battery pack includes a housing 60, a battery cell 10 disposed in the housing 60, and a battery cell assembly buckled on the housing 60. The housing 60 has a receiving cavity, and the battery cell 10 is disposed in the receiving cavity to support and protect the battery cell 10. Openings are further formed at both ends of the housing 60 to facilitate the placement of the battery cell 10, and the material of the housing 60 can be an insulating material.

[0051] The battery cell 10 is used to store and release electrical energy and is the core component of the battery. The battery cell 10 can be a wound core, that is, the battery cell 10 has a wound structure. In other examples, the battery cell 10 can also be a stacked core, that is, the battery cell 10 has a stacked structure. The battery cell 10 includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet. When the battery cell 10 works, active ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode sheet and the negative electrode sheet, and the separator is used to prevent the positive electrode sheet and the negative electrode sheet from short-circuiting and allow the active ions to pass through.

[0052] Among them, the positive electrode sheet forms the positive electrode of the battery cell 10 and includes a positive electrode sheet current collector and positive electrode active material disposed on at least one surface of the positive electrode current collector. The negative electrode sheet forms the negative electrode of the battery cell 10 and includes a negative electrode sheet current collector and negative electrode active material disposed on at least one surface of the negative electrode sheet current collector. The positive electrode sheet current collector and the negative electrode sheet current collector can both adopt existing structures and materials, and the positive electrode active material and the negative electrode active material can both adopt existing materials, which will not be elaborated here.

[0053] The battery cell assembly is used to cooperate with the housing 60 to seal the battery cell 10 therein. The battery cell assembly includes a cover plate and an alarm device 30. The cover plate has a pole column 20, and the pole column 20 includes a protector 21. The battery cell 10 is connected to an external port through the protector 21 to form a current path. When the protector 21 meets the disconnection condition, the current path is disconnected. The disconnection conditions include at least one of the current exceeding a first threshold and the temperature exceeding a second threshold.

[0054] Among them, the protector 21 can be a fuse. The fuse selects the specification model according to the magnitude of the charge and discharge current (i.e., the working current) of the designed battery cell 10 so that the first threshold is adapted to the battery cell 10. When a self-short circuit occurs inside the battery cell 10, the current exceeds the working current, and the fuse automatically disconnects. The protector 21 can also be an insulation-conductive transition body that automatically disconnects according to the temperature rise, etc. The second threshold is adapted to the working current of the battery cell 10. For example, the second threshold is 55 °C.

[0055] By using the protector 21 to disconnect the current path when the current exceeds the first threshold and / or the temperature exceeds the second threshold, the battery cell 10 can be timely disconnected from the outside world in the case of an internal short circuit or overheating of the battery cell 10, avoiding continuous short circuit or overheating of other battery cells 10, thereby reducing heat diffusion and thermal runaway and improving the safety of the battery pack.

[0056] The alarm device 30 is arranged on the cover plate, and the alarm device 30 is supported and fixed by electrodes. The alarm device 30 is connected to the protector 21. Exemplarily, the alarm device 30 is connected in parallel with the two end pins of the fuse of the negative cover plate, and is conducted by the connecting wire 31 embedded in the cover plate to form a current branch. The alarm device 30 gives an alarm when the temperature exceeds the third threshold, where the third threshold is less than the second threshold. For example, the third threshold is 40 °C. With such a setting, when the battery cell 10 has an internal short circuit or overheating, it can prompt personnel to operate on the battery pack, improving the safety of the battery pack.

[0057] In some possible examples, the cover plate includes a positive cover plate and a negative cover plate. The positive cover plate and the negative cover plate are respectively buckled on the openings at both ends of the housing. The positive cover plate is connected to the positive electrode plate of the battery cell 10 through an ear (such as a positive ear), and the negative cover plate is connected to the negative electrode plate of the battery cell 10 through another ear (such as a negative ear).

[0058] Both the positive cover plate and the negative cover plate include a cover plate body and a pole column 20 arranged in the cover plate body, and a protector 21 is arranged in each pole column 20. By embedding the protector 21 in the pole column 20 of the positive cover plate and embedding the protector 21 in the pole column 20 of the negative cover plate, the battery cell 10 ( Figure 1 and Figure 2 shown as G1), the protectors 21 of the two pole columns 20 ( Figure 1 and Figure 2 shown as F1 and F2), and the external ports ( Figure 1 and Figure 2 shown as X1 and X2) form a current path.

[0059] Refer to Figure 1 and Figure 2 , when the battery cell 10 is in a normal working state, the current passes through the pole column 20 of the positive cover plate, the external port, and the pole column 20 of the negative cover plate from the positive ear of the battery cell 10 to complete a normal current cycle. The protector 21 inside each pole column 20 is in a normal working state at this time, and the alarm device 30 is not working. When the battery cell 10 is in an abnormal working state, this battery cell assembly can play a triple protection role for the battery pack. Specifically:

[0060] When there is only a micro short circuit inside the battery cell 10, at this time, the temperature of the battery cell 10 exceeds the normal working temperature, but there is no obvious self - short - circuit phenomenon. The alarm device 30 gives an alarm according to the rising temperature when the temperature exceeds the third threshold.

[0061] When there is an obvious self - short - circuit phenomenon inside the battery cell 10, and the internal current does not exceed the upper limit of the working current of each protector 21 (that is, the current does not exceed the first threshold) or the temperature of the battery cell 10 does not exceed the second threshold, the alarm device 30 can continuously perform its function.

[0062] When the internal current exceeds the upper limit of the operating current of each protector 21 (i.e., the current exceeds the first threshold) or the temperature of the battery cell 10 exceeds the second threshold, the protector 21 disconnects at this time, forming an open circuit point to prevent the entire battery pack from being damaged.

[0063] In some possible embodiments, referring to Figure 1 and Figure 2 , the alarm device 30 includes a temperature sensor, a normally open temperature control switch B1, and an alarm LS1 connected in series. When the temperature of the battery cell 10 exceeds the third threshold, the normally open temperature control switch B1 closes, and the alarm LS1 gives an alarm.

[0064] Among them, one end of the normally open temperature control switch B1 is connected to one end of the alarm LS1, the other end of the normally open temperature control switch B1 is connected to one end of the temperature sensor, and the other ends of the temperature sensor and the alarm LS1 are respectively connected to both ends of the protector 21. The normally open temperature control switch is selected according to the operating temperature of the battery cell 10. Under overheating conditions, the normally open temperature control switch closes to make the alarm work, and the alarm can be a buzzer or the like.

[0065] Among them, the alarm device 30 further includes an external protective case. Electronic components such as a normally open temperature sensor and an alarm are arranged inside the external protective case. The external protective case plays a role in protecting against collision, moisture, and other current conduction for the electronic components inside it, and its base material can be selected from common rigid plastics. The normally open temperature sensor and the buzzer are connected by wires and led out through the wires.

[0066] In some possible embodiments, the alarm device 30 is arranged on the cover body of the positive electrode cover plate and / or the negative electrode cover plate. In this way, it is possible to prevent the battery pack from being conducted through the alarm device 30 connected in parallel with the protector 21, so as to ensure that the protector 21 can timely disconnect the current path. The cover body of one of the positive electrode cover plate and the negative electrode cover plate further includes a fireproof layer 44. Exemplarily, the alarm device 30 is arranged on the cover body of the negative electrode cover plate, and the cover body of the positive electrode cover plate includes the fireproof layer 44. The fireproof layer 44 does not burn under high temperature conditions and can isolate heat transfer, and common silicate materials are used as the base material.

[0067] The cover body of the positive electrode cover plate and the negative electrode cover plate where the alarm device 30 is not arranged also includes a fireproof layer 44. By separately arranging the alarm device 30 and the fireproof layer 44 on the cover bodies of the positive electrode cover plate and the negative electrode cover plate, on the one hand, it is possible to prevent the flame from spreading outward under the condition of internal short circuit of the battery cell 10 and improve the safety of the battery pack. On the other hand, it is possible to avoid the influence of the heat insulation and fire resistance effect of the fireproof layer 44 on the alarm device 30 and ensure that the alarm device 30 can normally monitor the temperature of the battery cell 10.

[0068] Referring to Figures 3 to 7, the cover body includes a cover surface layer 41, an insulating layer 42 disposed on one side of the cover surface layer 41, and a lead-out layer 43 disposed on the side of the insulating layer 42 away from the cover surface layer 41. Through holes are provided in the cover surface layer 41, the insulating layer 42, and the lead-out layer 43. The protector 21 is disposed in the through hole and communicates with the lead-out layer 43. The lead-out layer 43, the insulating layer 42, and the cover surface layer 41 are stacked in sequence, and the lead-out layer 43 is connected to the ear adjacent to the battery cell 10.

[0069] Among them, the cover surface layer 41 has a certain strength and is resistant to deformation, and a common aluminum alloy is used as the base material. The insulating layer 42 has sufficient strength and excellent insulation to prevent short circuit between the lead-out layer 43 and the cover surface layer 41 from causing safety problems, and common insulating plastics or insulating ceramics are used as the base material.

[0070] In some possible examples, the positive cover further includes a fireproof layer 44, and the fireproof layer 44 is disposed between the insulating layer 42 and the lead-out layer 43. The cover surface layer 41, the insulating layer 42, and the fireproof layer 44 of the positive cover are fastened and fixed through corresponding card slots and buckles, and the lead-out layer 43 is fastened on the fireproof layer 44. The insulating layer 42 of the negative cover is a top spacer ring, and the cover surface layer 41 and the top spacer ring of the negative cover are fastened and fixed through corresponding card slots and buckles, and the lead-out layer 43 is fastened on the top spacer ring.

[0071] In some possible examples, the negative cover further includes an explosion-proof valve 45 and an explosion-proof valve protection piece 46 disposed on the explosion-proof valve 45. The explosion-proof valve 45 is an important component to ensure the safe use of the battery pack. When the internal pressure of the battery pack rises to a certain value, the explosion-proof valve 45 is broken through, avoiding the occurrence of the battery pack bulging and exploding, and common aluminum alloy or stainless steel is used as the base material. The explosion-proof valve 45 is connected to the cover surface layer 41 of the negative cover by laser welding.

[0072] The through hole penetrates the cover surface layer 41, the insulating layer 42, and the lead-out layer 43 to install the pole column 20, and the protector 21 of the pole column 20 also communicates with the lead-out layer 43. In the example where the positive cover includes the fireproof layer 44, the pole column 20 also penetrates the fireproof layer 44. The pole column 20 and the lead-out layer 43 are connected by brazing to play a role in current conduction. For example, the pin at the first end of the fuse and the lead-out layer 43 are connected by brazing to form a current path.

[0073] Refer to Figures 2 to 7 , the pole column 20 further includes a connecting portion 22 and a pole column cover 23. The connecting portion 22 is disposed on the side of the protector 21 adjacent to the lead-out layer 43 and abuts against the lead-out layer 43, and a part of the connecting portion 22 also extends into the through hole of the lead-out layer 43. The pole column cover 23 is disposed on the side of the protector 21 away from the connecting portion 22 to form an external port.

[0074] Such as Figures 2 to 7As shown, the terminal post cover 23 is disposed above the protector 21, and the connecting portion 22 is disposed below the protector 21. The connecting portion 22 may be stepped, penetrate through the through hole of the lead-out layer 43, and abut against the surface of the lead-out layer 43 adjacent to the cover plate surface 41. By providing the connecting portion 22, the connection between the terminal post 20 and the lead-out layer 43 can be achieved. The terminal post cover 23 can be connected to the pin of the second end of the fuse by soldering to form an external port, thereby forming a current path, that is, the terminal post cover 23, both ends of the fuse, and the lead-out layer 43 are connected by soldering to form a current path.

[0075] In some possible examples, the end face of the connecting portion 22 facing the terminal post cover 23 includes a first central region and a first edge region surrounding the first central region, and the protector 21 is opposite to the first central region of the connecting portion 22; and / or, the end face of the terminal post cover 23 facing the connecting portion 22 includes a second central region and a second edge region surrounding the second central region, and the protector 21 is opposite to the second central region of the terminal post cover 23.

[0076] In this way, the outer peripheral surface of the protector 21 is recessed from the outer peripheral surface of the connecting portion 22, and / or, the outer peripheral surface of the protector 21 is recessed from the outer peripheral surface of the terminal post cover 23. Along the circumferential direction of the terminal post 20, at least one of the connecting portion 22 and the terminal post cover 23 protrudes from the protector 21, which can reduce the damage to the protector 21. Among them, the base material of the connecting portion 22 may be the same as that of the terminal post cover 23, for example, both are metals.

[0077] Continue to refer to Figures 2 to 7 , the terminal post 20 further includes a protection ring 24, and the protection ring 24 is sleeved on the protector 21. By providing the protection ring 24 outside the protector 21 and surrounding the protector 21, it can play a role in heat insulation and insulation against external current, and enable the protector 21 to function safely and stably. Among them, both ends of the protection ring 24 can be aligned with both ends of the protector 21, so that the protector 21 abuts against both the terminal post cover 23 and the connecting portion 22, that is, both ends of the protection ring 24 are in contact with the connecting portion 22 and the terminal post cover 23 respectively. The outer peripheral surface of the protection ring 24 can be aligned with the outer peripheral surfaces of the terminal post cover 23 and the end of the connecting portion 22 adjacent to each other. The base material of the protection member can be ceramics, etc.

[0078] Both the positive electrode cover plate and the negative electrode cover plate further include an isolation ring 51, a gasket 52, and a sealing ring 53. The isolation ring 51, the gasket 52, and the sealing ring 53 are all sleeved on the terminal post 20. The gasket 52 is disposed on the cover plate body, the sealing ring 53 is disposed between the terminal post 20 and the gasket 52, and the isolation ring 51 is disposed on the side of the gasket 52 away from the cover plate body and abuts against the terminal post cover 23.

[0079] Specifically, the sealing ring 53 is sleeved on the terminal post 20 and abuts against the terminal post 20, for example, it contacts the outer peripheral surface of the protection ring 24. The gasket 52 is sleeved on the sealing ring 53 and abuts against the sealing ring 53 to play the role of insulation and sealing, preventing the internal electrolyte from permeating. Among them, the cover plate body is correspondingly provided with a groove, the bottom wall of the groove is correspondingly provided with a through hole, and the gasket 52 is correspondingly arranged in the groove. The isolation ring 51 is sleeved on the terminal post 20 and is located on the side of the gasket 52 away from the cover plate body. The isolation ring 51 abuts against both the terminal post cover 23 and the gasket 52 to ensure insulation isolation between the terminal post 20 and the cover plate surface layer 41. The base material of the isolation ring 51 can be ceramics or the like.

[0080] It can be understood that the terminal post 20 (including the protector 21, the connecting part 22 and the terminal post cover 23), the protection ring 24, the gasket 52, the sealing ring 53, the cover plate body, the insulating layer 42, the fireproof layer 44 and the lead-out layer 43 form the positive electrode cover plate. The terminal post 20 (including the protector 21, the connecting part 22 and the terminal post cover 23), the protection ring 24, the gasket 52, the sealing ring 53, the cover plate body, the insulating layer 42 (i.e., the top spacer ring), the lead-out layer 43 and the explosion-proof valve 45 form the negative electrode cover plate.

[0081] In summary, in the embodiment of the present application, the battery cell assembly includes an electrode cover plate and an alarm device 30. The cover plate has a terminal post 20, and the terminal post 20 includes a protector 21. The protector 21 is configured to: be connected to the battery cell 10 and an external port to form a current path, and disconnect the current path when the current exceeds the first threshold and / or the temperature exceeds the second threshold. The alarm device 30 is connected to the protector 21, and the alarm device 30 gives an alarm when the temperature exceeds the third threshold, and the third threshold is less than the second threshold. By setting the protector 21 and the alarm device 30, it is possible to give a prompt alarm and disconnect from the external circuit in time in the case of internal short circuit or overheat of the battery cell 10, improving the safety of the battery pack.

[0082] In this specification, the embodiments or implementation manners are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0083] It should be noted that the embodiments referred to as "an embodiment", "embodiment", "exemplary embodiment", "some embodiments", etc. in the specification may include specific features, structures or characteristics, but not necessarily each embodiment includes the specific feature, structure or characteristic. In addition, such phrases do not necessarily refer to the same embodiment. Moreover, when combining a specific feature, structure or characteristic with an embodiment, it is within the knowledge scope of those skilled in the art to implement such a feature, structure or characteristic in combination with other embodiments, whether explicitly or implicitly described.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell assembly, characterized in that, include: A cover plate and an alarm device (30), wherein the cover plate has a pole (20), the pole (20) includes a protector (21), the battery cell (10) is connected to an external port via the protector (21), forming a current path; the protector (21) disconnects the current path when a disconnection condition is met; the disconnection condition includes at least one of a current exceeding a first threshold value and a temperature exceeding a second threshold value; The alarm device (30) is connected to the protector (21), and the alarm device (30) issues an alarm when the temperature exceeds a third threshold value, wherein the third threshold value is smaller than the second threshold value.

2. The cell assembly according to claim 1, wherein, The alarm device (30) comprises a temperature sensor, a normally open temperature control switch and an alarm connected in series. When the temperature exceeds the third threshold, the normally open temperature control switch is closed and the alarm sounds an alarm.

3. The cell assembly according to claim 2, wherein The cover plate includes a positive cover plate and a negative cover plate, and the positive cover plate and the negative cover plate each include a cover plate body and the pole (20) arranged in the cover plate body; The alarm device (30) is arranged on the cover plate body of the positive electrode cover plate and / or the negative electrode cover plate.

4. The cell assembly according to claim 3, wherein The cover plate body of one of the positive electrode cover plate and the negative electrode cover plate further includes a fireproof layer (44).

5. The cell assembly according to claim 2, wherein, The second threshold is 55°C, and the third threshold is 40°C.

6. The cell assembly according to any one of claims 1-5, characterized in that, The cover plate body comprises a cover plate surface layer (41), an insulating layer (42) arranged on one side of the cover plate surface layer (41), and a lead-out layer (43) arranged on a side of the insulating layer (42) away from the cover plate surface layer (41); The cover plate surface layer (41), the insulating layer (42) and the lead layer (43) are all provided with through holes, the pole (20) is arranged in the through hole, and the protector (21) is connected to the lead layer (43).

7. The cell assembly according to claim 6, wherein The pole (20) further includes a connecting portion (22) and a pole cover (23); The connecting portion (22) is arranged on a side of the protector (21) adjacent to the lead-out layer (43) and abuts against the lead-out layer (43); a portion of the connecting portion (22) also extends into a through hole of the lead-out layer (43); and the pole cover (23) is arranged on a side of the protector (21) away from the connecting portion (22) to form the external port.

8. The battery core assembly according to claim 7, characterized in that: The end surface of the connecting portion (22) facing the pole cover (23) includes a first central area and a first edge area surrounding the first central area, and the protector (21) is opposite to the first central area of the connecting portion (22); and / or, The end surface of the pole cover (23) facing the connecting portion (22) includes a second central area and a second edge area surrounding the second central area, and the protector (21) is opposite to the second central area of the pole cover (23).

9. The cell assembly according to claim 7, wherein The pole (20) further includes a protective ring (24), and the protective ring (24) is sleeved on the protector (21); Both ends of the protection ring (24) are in contact with the connecting portion (22) and the pole cover (23) respectively.

10. The cell assembly according to claim 7, wherein The cover plate further comprises an isolation ring (51), a gasket (52) and a sealing ring (53), wherein the isolation ring (51), the gasket (52) and the sealing ring (53) are all sleeved on the pole (20); The gasket (52) is arranged on the cover body, the sealing ring (53) is arranged between the pole (20) and the gasket (52), and the isolation ring (51) is arranged on a side of the gasket (52) away from the cover body and abuts against the pole cover (23).

11. A battery pack, characterized in that, The invention comprises a shell (60), a battery cell (10) arranged in the shell (60), and a battery cell assembly according to any one of claims 1 to 10, which is fastened to the shell (60).

12. An electrical device, characterized in that, Including the battery pack according to claim 11.

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