Battery and electric device

Abstract

The utility model relates to a battery and an electric device. The battery comprises an electric connecting piece and battery monomers, the electric connecting piece is used for electrically connecting at least two battery monomers, and each battery monomer comprises a tab and a pole; a positive temperature coefficient element is electrically connected between the tab and the pole, and / or the positive temperature coefficient element is electrically connected between the pole and the electric connecting piece, and / or the pole is the positive temperature coefficient element. The battery and the electric device provided by the utility model have relatively high safety.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a battery and an electrical device. Background Technology

[0002] With the rapid development of the new energy industry, battery safety, as a crucial component, has gradually gained attention. Overcharging due to unforeseen factors such as charging malfunctions, BMS (Battery Management System) control failures, or circulating current-induced overcharging poses significant safety risks. Furthermore, when multiple battery cells are connected in parallel, thermal runaway in one cell can easily trigger thermal runaway in other connected cells, further exacerbating safety hazards. Utility Model Content

[0003] Therefore, it is necessary to provide a battery and power device that can improve battery safety in response to the above problems.

[0004] A battery, the battery comprising an electrical connector and battery cells, the electrical connector being used to electrically connect at least two battery cells, the battery cells comprising tabs and terminals;

[0005] A positive temperature coefficient element is electrically connected between the tab and the post, and / or a positive temperature coefficient element is electrically connected between the post and the electrical connector, and / or the post is a positive temperature coefficient element.

[0006] In some embodiments, a positive temperature coefficient element is electrically connected between the tab and the post, or a positive temperature coefficient element is electrically connected between the post and the electrical connector, or the post is a positive temperature coefficient element.

[0007] In some embodiments, the positive temperature coefficient element electrically connected between the tab and the post, and / or the positive temperature coefficient element between the post and the electrical connector is a positive temperature coefficient resistor.

[0008] In some embodiments, the positive temperature coefficient element electrically connected between the tab and the post, and / or the element between the post and the electrical connector is a sheet element or a filament element.

[0009] In some embodiments, the positive temperature coefficient element is a phase change element.

[0010] In some embodiments, the surface of the electrode post facing the tab is recessed to form a first slot, and the positive temperature coefficient electrically connected between the tab and the electrode post is at least partially engaged in the first slot.

[0011] In some embodiments, a second slot is provided on the surface of the electrode post facing away from the tab, and the positive temperature coefficient element electrically connected between the electrode post and the electrical connector is at least partially inserted into the second slot.

[0012] In some embodiments, the positive temperature coefficient element electrically connected between the electrode and the electrical connector is fully inserted into the second slot.

[0013] In some embodiments, the battery cells are arranged in rows to form battery packs, and a heat insulation element is provided between each two adjacent battery cells in the battery pack, and / or between each two adjacent rows of battery packs.

[0014] An electrical device comprising a battery as described in any of the above embodiments.

[0015] Compared with the prior art, this application has the following beneficial effects:

[0016] When the aforementioned battery and electrical device charge series- or parallel battery cells with a stable current within a certain range, and the battery experiences overcharging due to unforeseen factors, abnormally generating heat that diffuses into the battery's internal environment, the temperature and resistance of the positive temperature coefficient elements (PTC elements) of each battery cell rise rapidly. Consequently, the voltage of each battery cell's PTC element and the voltage of each battery cell also increase rapidly. This can be quickly detected by a battery status monitoring system, which will issue an abnormal signal, thereby cutting off the battery's charging circuit and allowing the battery to quickly stop overcharging. When battery cells are connected in parallel, if one battery cell experiences thermal runaway due to unforeseen reasons, the heat generated by the thermally runaway battery cell diffuses into the battery's internal environment, causing an increase in the resistance of the PTC elements of both the thermally runaway battery cell and the other battery cells connected in parallel that have not experienced thermal runaway. Simultaneously, other battery cells connected in parallel with the thermally runaway cell that have not experienced thermal runaway discharge to the thermally runaway cell, forming a discharge circuit with it. In each discharge circuit, the resistance of the positive temperature coefficient element increases, causing the discharge circuit current to drop rapidly, thus protecting the battery cells that have not experienced thermal runaway and providing a high level of safety. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a single battery cell in one embodiment of this application;

[0018] Figure 2 for Figure 1 The diagram shows a cross-sectional view of a single battery cell taken along the AA direction.

[0019] Figure 3This is a cross-sectional view of a battery cell cut along the AA direction in another embodiment of this application.

[0020] Icon labels:

[0021] 10. Battery cells;

[0022] 11. Outer shell; 111. Receiving cavity; 12. Electrode assembly; 121. Electrode tab; 13. Electrode post; 131. First slot; 132. Second slot; 14. Positive temperature coefficient element. Detailed Implementation

[0023] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0024] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0026] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0027] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0028] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0029] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0030] Overcharging of batteries due to unforeseen factors such as charging malfunctions, BMS (Battery Management System) control failures, or circulating current-induced overcharging poses significant safety risks. Furthermore, when multiple battery cells are connected in parallel, thermal runaway in one cell can easily trigger thermal runaway in other cells connected in parallel, further exacerbating safety hazards.

[0031] Please see Figure 1 and Figure 2To alleviate the aforementioned problems, the applicant, after in-depth research, designed a new battery. This battery includes an electrical connector and battery cells 10. The electrical connector is used to electrically connect at least two battery cells 10. Each battery cell 10 includes a tab 121 and a terminal 13. A positive temperature coefficient element 14 is electrically connected between the tab 121 and the terminal 13, and / or, a positive temperature coefficient element 14 is electrically connected between the terminal 13 and the electrical connector, and / or, the terminal 13 is a positive temperature coefficient element 14.

[0032] Specifically, the battery cell 10 includes a housing 11 and an electrode assembly 12. The housing 11 has a receiving cavity 111, and the electrode assembly 12 is disposed within the receiving cavity 111 of the housing 11, and the electrode assembly 12 has tabs 121. A terminal post 13 is disposed on the housing 11, and both the terminal post 13 and the electrical connector are located outside the receiving cavity 111. When the positive temperature coefficient element 14 is electrically connected between the tab 121 and the terminal post 13, the positive temperature coefficient element 14 is located within the receiving cavity 111 of the housing 11. When the positive temperature coefficient element 14 is electrically connected between the terminal post 13 and the electrical connector, the positive temperature coefficient element 14 is located outside the receiving cavity 111 of the housing 11.

[0033] The tab 121 includes a positive tab and a negative tab, and the terminal 13 includes a positive terminal and a negative terminal. A positive temperature coefficient element 14 is electrically connected between the tab 121 and the terminal 13. This can be understood as: a positive temperature coefficient element 14 is electrically connected between the positive tab and the positive terminal, and / or, a positive temperature coefficient element 14 is electrically connected between the negative tab and the negative terminal. A positive temperature coefficient element 14 is electrically connected between the terminal 13 and the electrical connector. This can be understood as: a positive temperature coefficient element 14 is electrically connected between the positive terminal and the electrical connector, and / or, a positive temperature coefficient element 14 is electrically connected between the negative terminal and the electrical connector. The positive temperature coefficient element 14 disposed between the tab 121 and the terminal 13, and the positive temperature coefficient element 14 disposed between the terminal 13 and the electrical connector, can be connected to the terminal 13 by welding, crimping, riveting, or other connection methods. The terminal 13 being a positive temperature coefficient element 14 can be understood as: the positive terminal and / or the negative terminal being a positive temperature coefficient element 14. When the electrode 13 is a positive temperature coefficient element 14, the electrode 13 can be formed by combining a positive temperature coefficient material with a metal material.

[0034] Preferably, a positive temperature coefficient element 14 is electrically connected between the tab 121 and the terminal 13, or a positive temperature coefficient element 14 is electrically connected between the terminal 13 and the electrical connector, or the terminal 13 is a positive temperature coefficient element 14. In this way, only one and at most two positive temperature coefficient elements 14 need to be provided within the battery cell 10 or between the battery cell 10 and the electrical connector. This design helps to reduce the number of positive temperature coefficient elements 14, simplify the battery structure, and reduce battery manufacturing costs.

[0035] The positive temperature coefficient element 14 is formed from a positive temperature coefficient material. As an example, the positive temperature coefficient material can be a composite of a polymer (e.g., a crystalline polymer such as polyethylene) and a conductive filler (carbon black, graphite, metal powder, etc.), or it can be formed by chemically and / or physically combining a metal (e.g., Fe, W, Mo, etc.) with vanadium trioxide (V₂O₃). The positive temperature coefficient element 14 is a component whose resistance increases with increasing current. A characteristic of this type of component is that the heat generated when current flows causes its temperature to rise, thereby increasing its resistance. Furthermore, the positive temperature coefficient element 14 needs to be conductive.

[0036] The electrical connector is a metallic conductor, typically an aluminum busbar, used for connecting at least two battery cells 10 in series or parallel via terminals 13. As an example, when the electrical connector connects two battery cells 10 via terminals 13 of the same polarity, parallel connection of the two battery cells 10 is achieved; when the electrical connector connects two battery cells 10 via terminals 13 of opposite polarity, series connection of the two battery cells 10 is achieved.

[0037] In this application, when a series- or parallel-connected battery cell 10 is charged with a current that remains stable within a certain range, and the battery experiences abnormal heat generation due to overcharging caused by unforeseen factors, which then diffuses into the battery's internal environment, the temperature of the positive temperature coefficient element 14 of each battery cell 10 rises rapidly, as does the resistance of the positive temperature coefficient element 14. Consequently, the voltage of both the positive temperature coefficient element 14 and the battery cell 10 increases rapidly. This rapid change in the resistance or voltage of the positive temperature coefficient element 14, or the rapid change in the total voltage of the battery cells 10, can be quickly detected by a battery status monitoring system, which will then issue an abnormal signal, thereby cutting off the battery's charging circuit and allowing the battery to quickly stop overcharging. Simultaneously, since the charging power supply voltage is typically stable within a certain range, the increase in the resistance of the positive temperature coefficient element 14 of each battery cell 10 leads to an increase in the total resistance in the battery charging circuit, thus reducing the current in the battery charging circuit. This reduces battery heat generation and ensures the safety of battery charging.

[0038] It is understandable that, taking the parallel connection of battery cells 10 as an example, each battery cell 10 and the charging power supply form a charging circuit. Taking the series connection of battery cells 10 as an example, all battery cells 10 and the charging power supply together form a charging circuit.

[0039] As an example, taking a monitoring system used to monitor the total voltage of a single battery cell 10, with the positive temperature coefficient element 14 disposed between the tab 121 and the terminal 13, the total voltage of the single battery cell 10 is defined as U. 总 The voltage of the positive temperature coefficient element 14 is U1, and the voltage of the battery cell 10 before the positive temperature coefficient element 14 is installed is U2.总 = U1 + U2. When the resistance of the positive temperature coefficient element 14 rises rapidly, and the current flowing through the battery cell 10 does not change significantly, then U1 increases while U2 remains approximately unchanged. It can be understood that the battery cell 10 before the positive temperature coefficient element 14 is installed has a certain resistance, and this resistance hardly changes with temperature. Furthermore, when the current is stable, the voltage across this resistance also remains essentially unchanged, or can be ignored. When U1 increases while U2 remains approximately unchanged, the voltage U... 总 The voltage will also rise rapidly, thus being quickly detected by the monitoring system, which will then issue an abnormal signal and cut off the battery circuit, allowing the battery to quickly stop overcharging. It is understandable that during normal battery charging, U... 总 The change is very small and can be ignored.

[0040] When battery cells 10 are connected in parallel, if any battery cell 10 experiences thermal runaway due to an unforeseen cause, that battery cell 10 will generate a thermal runaway resistance (a stable value within a certain range, for example, 0mΩ to 100mΩ). Simultaneously, the heat generated by the thermally runaway battery cell 10 diffuses into the internal environment of the battery, causing an increase in the resistance of the positive temperature coefficient element 14 of both the thermally runaway battery cell 10 and the other battery cells 10 connected in parallel that have not experienced thermal runaway. At the same time, the other battery cells 10 connected in parallel that have not experienced thermal runaway discharge to the thermally runaway battery cell 10, forming a discharge circuit with each of them. In each discharge circuit, I = U 电池 / (R1+2R2), where I is the current in the discharge circuit, U 电池 R1 is the voltage of the battery cell 10 that has not experienced thermal runaway during discharge, R2 is the thermal runaway resistance of the battery cell 10 that has experienced thermal runaway, and R2 is the resistance of the positive temperature coefficient element 14. Since both the battery cell 10 that has experienced thermal runaway and the battery cell 10 that has not experienced thermal runaway have one positive temperature coefficient element 14, there are two positive temperature coefficient elements 14 in the discharge circuit. 电池 When the resistance of the positive temperature coefficient element 14 stabilizes within a certain range, it increases, causing the current in the discharge circuit to drop rapidly, thus protecting the battery cells 10 that have not experienced thermal runaway. It is worth noting that the battery cells 10 that have experienced thermal runaway are already damaged and do not require protection.

[0041] In some embodiments, the positive temperature coefficient element 14 electrically connected between the tab 121 and the post 13, and / or between the post 13 and the electrical connector, is a positive temperature coefficient resistor (i.e., a PCT resistor). A positive temperature coefficient resistor does not glow red or produce an open flame when heated, and therefore is not easily flammable.

[0042] As an example, a positive temperature coefficient resistor can be formed from a material composed of a polymer (such as crystalline polymers like polyethylene) and conductive fillers (carbon black, graphite, metal powder, etc.).

[0043] In some embodiments, the positive temperature coefficient element 14 electrically connected between the tab 121 and the terminal 13, and / or between the terminal 13 and the electrical connector, is a sheet element or a filament element. Sheet elements or filament elements are smaller in size, occupy less battery space, and are beneficial to improving the battery's space utilization and energy density.

[0044] In some embodiments, the positive temperature coefficient element 14 is a phase change element. The phase change element absorbs heat, causing changes in its shape and resistance, which can be quickly detected by the monitoring system. Therefore, it can promptly cut off the battery circuit, allowing the battery to quickly stop overcharging. As an example, the phase change element can be made of a material formed by chemically and / or physically combining vanadium trioxide (V₂O₃) doped with metals (e.g., Fe, W, Mo, etc.).

[0045] In some embodiments, the surface of the electrode post 13 facing the tab 121 is recessed to form a first slot 131, and the positive temperature coefficient element 14 electrically connected between the tab 121 and the electrode post 13 is at least partially inserted into the first slot 131. Preferably, the positive temperature coefficient element 14 electrically connected between the tab 121 and the electrode post 13 is completely inserted into the first slot 131.

[0046] Specifically, such as Figure 2 As shown, a first slot 131 is formed by recessing the surface of either the positive or negative terminal toward the tab 121. The positive temperature coefficient element 14, which is electrically connected between the tab 121 and the positive or negative terminal, is at least partially inserted into the first slot 131.

[0047] This design can reduce the space occupied by the positive temperature coefficient element 14 inside the battery cell 10, which is beneficial to improving the space utilization and energy density of the battery.

[0048] Please see Figure 1 and Figure 3In some embodiments, a second slot 132 is formed on the surface of the electrode post 13 facing away from the electrode tab 121, and the positive temperature coefficient element 14 electrically connected between the electrode post 13 and the electrical connector is at least partially inserted into the second slot 132. Preferably, the positive temperature coefficient element 14 electrically connected between the electrode post 13 and the electrical connector is completely inserted into the second slot 132.

[0049] Specifically, such as Figure 3 As shown, a second slot 132 is formed by a recess on the surface of either the positive or negative terminal facing away from the tab 121, and the positive temperature coefficient element 14, which is electrically connected between the terminal 13 and the electrical connector, is fully inserted into the second slot 132.

[0050] This design can reduce the space occupied by the positive temperature coefficient element 14 inside the battery, which is beneficial to improving the space utilization and energy density of the battery.

[0051] Please refer to it again. Figure 1 In some embodiments, the battery cells 10 are arranged in rows to form battery packs, and a heat insulation element is provided between every two adjacent battery cells 10 in the battery pack, and / or between every two adjacent battery packs. Preferably, a heat insulation element is provided between every two adjacent battery cells 10 in the battery pack, and between every two adjacent battery packs.

[0052] As an example, battery cells 10 are arranged in rows to form multiple battery rows, with all battery rows arranged along the width direction of the battery and all battery cells 10 in each battery row arranged along the length direction of the battery.

[0053] Specifically, the thermal insulation element can be cardboard, sponge, or other thermal insulation structures. The design of the thermal insulation element can control the thermal runaway of the battery within a small range, thereby reducing the difficulty and cost of overall battery thermal protection. At the same time, it will reduce the high temperature and harmful substances emitted by the battery to the outside world, reducing secondary disasters caused by battery thermal runaway.

[0054] This application also provides an electrical device comprising a battery as described in the above embodiments. The electrical device in this application has the effects of any of the above embodiments, and therefore will not be repeated here.

[0055] The electrical devices can include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0056] It should be understood that the technical solutions described in the embodiments of this application are not limited to the electrical devices described above.

[0057] Please refer to it again. Figure 1 and Figure 2 When the aforementioned battery and electrical device charge series- or parallel battery cells 10 with a current that remains stable within a certain range, and the battery experiences overcharging due to unforeseen factors, abnormally generating heat that diffuses into the battery's internal environment, the temperature of the positive temperature coefficient element 14 of each battery cell 10 rises rapidly, and the resistance of the positive temperature coefficient element 14 of each battery cell 10 also rises rapidly. Consequently, the voltage of the positive temperature coefficient element 14 of each battery cell 10 and each battery cell 10 also increases rapidly. This can be quickly detected by a monitoring system that monitors the battery status, which then issues an abnormal signal, thereby cutting off the battery's charging circuit and allowing the battery to quickly stop overcharging. When battery cells 10 are connected in parallel, if one battery cell 10 experiences thermal runaway due to unforeseen reasons, the heat generated by the thermally runaway battery cell 10 diffuses into the battery's internal environment, causing an increase in the resistance of the positive temperature coefficient element 14 of both the thermally runaway battery cell 10 and the positive temperature coefficient element 14 of the other battery cells 10 connected in parallel that have not experienced thermal runaway. Simultaneously, other battery cells 10 connected in parallel with the thermally runaway battery cell 10 that have not experienced thermal runaway discharge to the thermally runaway battery cell 10, forming a discharge circuit with each of them. In each discharge circuit, the resistance of the positive temperature coefficient element 14 increases, causing the current in the discharge circuit to drop rapidly, thereby protecting the battery cells 10 that have not experienced thermal runaway and providing high safety.

[0058] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery, characterized in that, The battery includes an electrical connector and a battery cell (10). The electrical connector is used to electrically connect at least two battery cells (10). The battery cell (10) includes a tab (121) and a terminal (13). The tab (121) is electrically connected to the post (13) by a positive temperature coefficient element (14), and / or the post (13) is electrically connected to the electrical connector by a positive temperature coefficient element (14), and / or the post (13) is a positive temperature coefficient element (14).

2. The battery according to claim 1, characterized in that, The positive temperature coefficient element (14) electrically connected between the tab (121) and the post (13), and / or the positive temperature coefficient element (14) between the post (13) and the electrical connector is a positive temperature coefficient resistor.

3. The battery according to claim 1, characterized in that, The positive temperature coefficient element (14) electrically connected between the tab (121) and the post (13), and / or the positive temperature coefficient element (14) between the post (13) and the electrical connector is a sheet element or a filament element.

4. The battery according to claim 1, characterized in that, The positive temperature coefficient element (14) is a phase change element.

5. The battery according to claim 1, characterized in that, The surface of the pole post (13) facing the tab (121) is recessed to form a first slot (131), and the positive temperature coefficient electrically connected between the tab (121) and the pole post (13) is at least partially inserted into the first slot (131).

6. The battery according to claim 1, characterized in that, The electrode post (13) has a second slot (132) on its surface facing away from the electrode tab (121), and the positive temperature coefficient element (14) that is electrically connected between the electrode post (13) and the electrical connector is at least partially inserted into the second slot (132).

7. The battery according to claim 6, characterized in that, The positive temperature coefficient element (14) that is electrically connected between the pole (13) and the electrical connector is fully inserted into the second slot (132).

8. The battery according to claim 1, characterized in that, The battery cells (10) are arranged in rows to form a battery pack, and a heat insulation element is provided between each two adjacent battery cells (10) in the battery pack, and / or between each two adjacent rows of battery packs.

9. An electrical device, characterized in that, The electrical device includes a battery as described in any one of claims 1 to 8.

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