A single cell and a battery pack

Abstract

The application provides a single battery and a battery pack, and belongs to the technical field of batteries. The single battery comprises a shell, an electrode assembly, a top cover sheet, a pole, a deformation sheet and a conductive part. The electrode assembly is accommodated in the shell. The top cover sheet is connected with one end of the shell along a first direction. The pole is provided through the top cover sheet. The deformation sheet is a temperature sensing deformation sheet. The deformation sheet comprises a first deformation part and a second deformation part which are connected with each other. The first deformation part is fixedly connected with the pole. The second deformation part is arranged around the first deformation part. The conductive part comprises a conductive body and an insulating part which are connected with each other. The insulating part is fixedly connected with the first deformation part. The second deformation part is electrically connected with the conductive body. The second deformation part is configured to be separated from the conductive body when the temperature of the pole exceeds a preset temperature. In the single battery provided by the application, the deformation sheet is a temperature sensing deformation sheet. When the overcharging temperature is high, the deformation of the deformation sheet can cut off the electrical connection between the pole and the conductive body, so as to ensure the safety of the battery.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a single cell battery and a battery pack. Background Technology

[0002] Batteries play a vital role as energy storage units across various industries. For example, power batteries are widely used in new energy vehicles and other fields. A power battery pack can consist of multiple individual cells connected in series to form a battery module for charging and discharging. During the charging and discharging process, the power battery typically uses a BMS (Battery Management System) to monitor changes in voltage and current and calculate the state of charge.

[0003] If there is a problem with the voltage sampling, it may lead to overcharging of the battery. When the power battery is overcharged, it may cause safety accidents such as thermal runaway or thermal diffusion, resulting in poor safety. Utility Model Content

[0004] In view of this, the purpose of this application is to overcome the shortcomings of the prior art and provide a single cell battery and a battery holder.

[0005] In a first aspect, this application provides a single-cell battery having a first orientation, including: case, The electrode assembly is housed within the housing; A top cover plate is connected to one end of the housing along the first direction; The pole is inserted into the top cover plate; The deformable sheet is a temperature-sensitive deformable sheet. The deformable sheet is located on the side of the electrode post away from the electrode assembly. The deformable sheet includes a first deformable part and a second deformable part that are connected to each other. The first deformable part is fixedly connected to the electrode post, and the second deformable part is arranged around the first deformable part. A conductive element is located on the side of the deformable piece away from the electrode assembly along the first direction. The conductive element includes a conductive body and an insulating element connected along the first direction. The insulating element is fixedly connected to the first deformable part. The second deformable part is connected to the conductive body. The second deformable part is configured to separate from the conductive body when the electrode temperature exceeds a preset temperature.

[0006] In some embodiments, the conductive body is disposed around the insulating member, a portion of the second deformable portion near the first deformable portion is connected to the insulating member, and a portion of the second deformable portion away from the first deformable portion abuts against the conductive body.

[0007] In some embodiments, along the first direction, the conductive element has a first end and a second end disposed opposite to each other, the second end being located on the side away from the pole post, the cross-sectional area of ​​the conductive element gradually decreasing from the second end to near the first end, the insulating element being located at the first end, and the first end being fixedly connected to the first deformable portion.

[0008] In some embodiments, the single cell further has a second direction perpendicular to the first direction, the diameter of the insulating member gradually decreases from the second end to the first end along the first direction, and the maximum diameter of the insulating member along the second direction is greater than the diameter of the first deformed portion along the second direction.

[0009] In some embodiments, the single cell further includes a fixing part fixedly connected to the electrode post, the fixing part being located on the side of the top cover sheet opposite to the electrode assembly along the first direction, and the fixing part being arranged around the electrode post, the second deformation part being configured to separate from the conductive body when the temperature of the electrode post exceeds a preset temperature, and the second deformation part being connected to the fixing part.

[0010] In some embodiments, the single cell further has a second direction perpendicular to the first direction, and the diameter of the second deformed portion along the second direction is greater than the maximum diameter of the conductive element along the second direction.

[0011] In some embodiments, the second deformation portion is configured to separate from the conductive body when the electrode temperature exceeds a preset temperature, and a portion of the second deformation portion near the first deformation portion is connected to the electrode.

[0012] In some embodiments, the thickness of the second deformed portion along the first direction is less than the thickness of the insulating member along the first direction.

[0013] In some embodiments, the second deformable portion is connected to the first deformable portion to form a groove, the groove being located on the side away from the electrode post along the first direction, and the groove being recessed along the first direction towards the electrode assembly.

[0014] Secondly, this application provides a battery pack including the aforementioned single battery cell.

[0015] The embodiments of this application have the following advantages: by providing a deformable sheet between the terminal and the conductive element, the deformable sheet includes a first deformable portion and a second deformable portion, and the conductive element includes a conductive body and an insulating element, and a portion of the second deformable portion is electrically connected to the conductive body, the first deformable portion is fixedly connected to the terminal on one side along the first direction, and the first deformable portion is fixedly connected to the insulating element on the other side along the first direction, thereby ensuring the stability of the connection between the fixing element and the terminal; in addition, the deformable sheet is a temperature-sensitive deformable sheet, when an overcharge temperature is high, the second deformable portion separates from the conductive body, thereby disconnecting the terminal from the conductive body through the deformable sheet to ensure the safety of the battery.

[0016] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This paper shows a schematic diagram of the structure of a single-cell battery from one perspective, based on some embodiments of this application. Figure 2 This invention provides a schematic diagram of the top cover sheet in a single-cell battery from one perspective, based on some embodiments of the present application. Figure 3 A cross-sectional view of a first embodiment of a top cover sheet in a single-cell battery provided by some embodiments of this application is shown; Figure 4 It shows Figure 3 Enlarged view of section A in the middle; Figure 5 A cross-sectional view of a second embodiment of a top cover sheet in a single-cell battery provided by some embodiments of this application is shown; Figure 6 It shows Figure 5 Enlarged view of section B; Figure 7 This illustration shows a schematic diagram of the internal structure of a single-cell battery according to some embodiments of this application.

[0019] Explanation of key component symbols: 100-Housing; 200-Electrode assembly; 300-Top cover plate; 410-Electrode post; 420-Fixing part; 500-Deformable piece; 600-Conductive component; 610-Conductive body; 620-Insulating component; 630-First end; 640-Second end; 510-First deformable part; 520-Second deformable part.

[0020] Z - First direction; X - Second direction. Detailed Implementation

[0021] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0022] It should be noted that when an element is said to be "fixed" to another element, it can be directly on the other element or there may be an intervening element. When an element is said to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element. Conversely, when an element is said to be "directly" on another element, there is no intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0023] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] 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 one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the template description is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 7 As shown, some embodiments of this application provide a single-cell battery, mainly used to prevent overheating, aging and melting of the single-cell battery, and to improve the safety of the single-cell battery during charging and discharging.

[0027] The single cell includes a casing 100, an electrode assembly 200, a top cover plate 300, a terminal post 410, a deformable plate 500, and a conductive component 600.

[0028] The electrode assembly 200 is housed within the housing 100, so that the housing 100 provides a limiting and protective function for the electrode assembly 200, thereby ensuring the stability of the electrode assembly 200 within the housing 100.

[0029] The top cover plate 300 is connected to one end of the housing 100 along the first direction Z, and seals the housing 100 with the top cover plate 300 to limit the electrode assembly 200 along the first direction Z, thereby further ensuring the stability of the electrode assembly 200 within the housing 100. The connection method between the housing 100 and the top cover plate 300 includes any one of snap-fit, adhesive, welding, thermofusion connection, and threaded connection, which can be specifically set according to the actual situation.

[0030] The electrode post 410 is inserted through the top cover plate 300 along the first direction Z. That is, a part of the electrode post 410 is located on the side of the top cover plate 300 facing the housing 100 along the first direction Z, and a part of the electrode post 410 is exposed on the side of the top cover plate 300 away from the housing 100 along the first direction Z. This part of the electrode post 410 located inside the housing 100 is electrically connected to the tab on the electrode assembly 200.

[0031] The deformable piece 500 is located on the side of the electrode post 410 away from the electrode assembly 200. The deformable piece 500 includes a first deformable part 510 and a second deformable part 520 connected to each other. The first deformable part 510 is fixedly connected to the electrode post 410. The connection method between the first deformable part 510 and the electrode post 410 includes any one of hot melt connection, bonding, welding or snap-fit, which can be specifically set according to the actual situation.

[0032] In this embodiment, the second deformable portion 520 is disposed around the first deformable portion 510, and the second deformable portion 520 is deformable relative to the first deformable portion 510. It should be noted that both the first deformable portion 510 and the second deformable portion 520 are conductive.

[0033] Additionally, the conductive element 600 is located on the side of the deformable piece 500 facing away from the electrode assembly 200 along the first direction Z. The conductive element 600 includes a conductive body 610 and an insulating element 620 connected along the first direction Z. The insulating element 620 is fixedly connected to the first deformable part 510, and the second deformable part 520 is electrically connected to the conductive body 610. Thus, the conductive element 600 is electrically connected to the electrode post 410 through the first deformable part 510 and the second deformable part 520. The second deformable part 520 is configured to separate from the conductive body 610 when the temperature of the electrode post 410 exceeds a preset temperature.

[0034] It is understood that the deformable sheet 500 provided in this application has a second deformable part 520 that can undergo a first deformation when the temperature is greater than a preset temperature value, and disconnect the second deformable part 520 from the conductive body 610; the second deformable part 520 can undergo a second deformation when the temperature is equal to or less than the preset temperature value, and abut the deformable sheet against the conductive body 610 and be electrically connected to the conductive body 610.

[0035] Specifically, in this embodiment, the second deformation part 520 is a temperature-sensitive deformation sheet. When an overcharge temperature is high, the deformation sheet can cut off the electrical connection between the terminal and the conductive body to ensure the safety of the battery.

[0036] For example, the deformable sheet 500 can undergo a first deformation when the temperature is greater than a preset temperature value, and disconnect the second deformable part 520 from the conductive body 610, thereby disconnecting the deformable sheet 500 from the conductive body 610; the second deformable part 520 can undergo a second deformation when the temperature is equal to or less than the preset temperature value, causing the second deformable part 520 to abut against the conductive body 610, and electrically connecting the second deformable part 520 to the conductive body 610, thereby electrically connecting the deformable sheet 500 to the conductive body 610.

[0037] It is understandable that by providing an insulating member 620 between the conductive body 610 and the deformable piece 500, when the temperature of the deformable piece 500 exceeds a preset temperature value, it indicates that the temperature of the single cell has increased during charging and discharging. The second deformable part 520 can deform, and the second deformable part 520 and the conductive body 610 are disconnected. The insulating member 620 forms an insulating barrier between the first deformable part 510 and the conductive body 610, thereby ensuring that the conductive body 610 and the terminal post 410 are disconnected. This prevents the single cell from overheating, aging, and melting, improves the safety of the single cell during charging and discharging, and thus protects the electrode assembly 200.

[0038] When the temperature of the terminal 410 in the single cell is less than or equal to the preset temperature, it indicates that the temperature in the single cell is not high. At this time, the second deformation part 520 does not deform relative to the first deformation part 510, so as to ensure the stability of the connection between the second deformation part 520 and the conductive body 610.

[0039] like Figures 4 to 6 As shown, in some embodiments of this application, the conductive body 610 is disposed around the insulating member 620, and a portion of the second deformable portion 520 near the first deformable portion 510 is connected to the insulating member 620, so that the insulating member 620 forms an insulating barrier between the conductive body 610 and the first deformable portion 510 to prevent the first deformable portion 510 from directly contacting the conductive body 610, thereby ensuring the quality of the insulating barrier between the insulating member 620 and the conductive body 610.

[0040] The connection method between the conductive body 610 and the insulating component 620 includes any one of snap-fit, adhesive, threaded connection, and tenon-mortise connection, which can be specifically set according to the actual situation.

[0041] In this configuration, a portion of the second deformable portion 520 away from the first deformable portion 510 is electrically connected to the conductive body 610, thereby electrically connecting the first deformable portion 510 to the conductive body 610 through the second deformable portion 520, and thus electrically connecting the conductive body 610 to the pole post 410 through the deformable piece 500.

[0042] It should be noted that the side of the second deformable part 520 facing the conductive body 610 abuts against the conductive body 610, thereby forming an electrical connection between the second deformable part 520 and the conductive body 610. In other words, the second deformable part 520 and the conductive body 610 are movably connected.

[0043] In this embodiment, by movably connecting the second deformation part 520 to the conductive body 610, when the temperature of the single cell rises, the second deformation part 520 can deform relative to the first deformation part 510 when the temperature is greater than a preset temperature value. The second deformation part 520 deforms along the first direction Z towards the terminal post 410, so that the second deformation part 520 moves away from the conductive body 610 and disconnects the second deformation part 520 from the conductive body 610, thereby disconnecting the conductive body 610 from the terminal post 410 to prevent the single cell from overheating, aging, and melting.

[0044] like Figure 4 and Figure 6 As shown, in some embodiments of this application, along the first direction Z, the conductive member 600 has a first end 630 and a second end 640 disposed opposite each other. The second end is located on the side away from the pole post. The cross-sectional area of ​​the conductive member 600 gradually decreases from the second end 640 to near the first end 630. The insulating member 620 is located at the first end 630, and the first end 630 is fixedly connected to the pole post 410. That is, the projection of the second end 640 along the first direction Z onto the plane of the top cover 300 covers the insulating member 620, thereby improving the convenience and stability of connecting the second deformable part 520 to the conductive body 610.

[0045] like Figure 4 and Figure 6 As shown, in some embodiments of this application, the single cell battery also has a second direction X perpendicular to the first direction Z, the diameter of the insulating member 620 gradually decreases from the second end 640 to the first end 630 along the first direction Z, and the maximum diameter of the insulating member 620 along the second direction X is greater than the diameter of the first deformed portion 510 along the second direction X.

[0046] It is understandable that the projection of the first end 630 onto the plane of the top cover plate 300 along the first direction Z covers the first deformable part 510. Since the insulating member 620 is provided at the first end 630, the first deformable part 510 is insulated from the conductive body 610 through the first end 630, so as to prevent the first deformable part 510 from being directly connected to the conductive body 610.

[0047] In this embodiment, the deformable piece 500 is used to deform when the temperature of the electrode post 410 exceeds a preset temperature, and the deformed second deformable part 520 is fixedly connected to the electrode post 410. That is, when the temperature of the electrode post 410 exceeds the preset temperature, the second deformable part 520 deforms towards the electrode post 410, spaced apart from the conductive body 610, and connected to the electrode post 410. When the temperature of the electrode post 410 is lower than the preset temperature, the second deformable part 520 deforms towards the conductive body 610 and connects to the conductive body 610 to prevent the temperature of the single cell from becoming too high and to ensure the safety of the single cell.

[0048] like Figure 4 and Figure 6 As shown, in some embodiments of this application, the diameter of the second deformable portion 520 along the second direction X is larger than the diameter of the conductive member 600 along the second direction X, so that the projection of the second deformable portion 520 along the first direction Z onto the plane where the top cover plate 300 is located can completely cover the projection of the conductive member 600 along the first direction Z onto the plane where the top cover plate 300 is located. That is, along the first direction Z, the second deformable portion 520 at least partially overlaps with the conductive body 610 in the conductive member 600, so as to ensure that the second deformable portion 520 can be electrically connected to the conductive body 610, thereby ensuring the stability of the connection between the second deformable portion 520 and the conductive body 610.

[0049] It is understood that the shape of the conductive element 600 can be any of the following: a pyramid, a cone, or a frustum.

[0050] like Figures 3 to 6 As shown, in some embodiments of this application, the single battery cell further includes a fixing part 420 fixedly connected to the electrode post 410. The fixing part 420 is located on the side of the top cover plate 300 away from the electrode assembly 200 along the first direction Z, and the fixing part 420 is arranged around the electrode post 410. The second deformation part 520 is configured to separate from the conductive body 610 when the temperature of the electrode post 410 exceeds a preset temperature, and to disconnect the second deformation part 520 from the conductive body 610. The second deformation part 520 is connected to the fixing part 420 so that the fixing part 420 limits the second deformation part 520 in the first direction Z, so as to ensure the stability of the second deformation part 520 in the fixing part 420.

[0051] In some embodiments, the thickness of the second deformable portion 520 along the first direction Z is less than the thickness of the insulating member 620 along the first direction Z. By reducing the thickness of the second deformable portion 520 in the first direction, the stress resisting deformation generated by the second deformable portion 520 during deformation is reduced, so that the second deformable portion 520 is easier to deform.

[0052] like Figure 6 As shown, in some embodiments of this application, the second deformation portion 520 is configured to separate from the conductive body 610 when the temperature of the electrode post 410 exceeds a preset temperature, and a portion of the second deformation portion 520 near the first deformation portion 510 is connected to the electrode post 410 to prevent the first deformation portion 510 from being directly connected to the conductive body 610. This ensures that after the second deformation portion 520 separates from the conductive body 610, both the second deformation portion 520 and the first deformation portion 510 are simultaneously disconnected from the conductive body 610, thereby preventing the electrode post 410 from connecting to the conductive body 610 through the deformable piece 500 when the temperature of the electrode post 410 exceeds the preset temperature, thus ensuring the safety of the battery.

[0053] In addition, in some embodiments of this application, the second deformable portion 520 is connected to the first deformable portion 510 to form a groove. The groove is located on the side away from the electrode post 410 along the first direction Z, and the groove is located at the connection between the first deformable portion 510 and the second deformable portion 520. The groove is recessed along the first direction Z towards the electrode assembly 200. The groove surrounds the first deformable portion 510 to reduce the thickness of the connection between the first deformable portion 510 and the second deformable portion 520, so that the second deformable portion 520 deforms relative to the first deformable portion 510.

[0054] In some embodiments of this application, the deformable sheet 500 includes a first expansion alloy layer, a conductive layer, and a second expansion alloy layer stacked sequentially. In this embodiment, the first expansion alloy layer is an expansion layer alloy Ni. 20 The Mn6 layer, and the second expansion alloy layer is expanded Ni. 36 Layer. In this embodiment, the specific bending of the deformable sheet 500 is 13.5 × 10⁻⁶. -6 / ℃, elastic modulus is 1.62×10 5 N / mm 2 The resistivity is 5.8 μΩ*cm. The deformation temperature of the deformable sheet 500 is 100-260℃.

[0055] It is understandable that the deformation temperature of the deformable sheet 500 can be any value among 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, and 260℃.

[0056] The expansion coefficient of the first expansion alloy layer is greater than that of the second expansion alloy layer, and the first expansion alloy layer is located on the side of the second expansion alloy layer facing the conductive element 600. In other words, the deformable sheet 500 is a bimetallic sheet.

[0057] It should be noted that the larger the coefficient of thermal expansion of an alloy sheet, the greater the deformation (bending) it will produce when the temperature changes. The coefficient of thermal expansion is a physical quantity that refers to the degree of expansion of a material's length, area, or volume when the temperature rises. The larger the coefficient of thermal expansion, the more the material expands or contracts under the same temperature change.

[0058] It should be noted that the first expansion alloy layer is located on the side of the second expansion alloy layer facing the conductive element 600, that is, the second expansion alloy layer is located on the side of the first expansion alloy layer facing the pole post 410, that is, a part of the second expansion alloy layer is fixedly connected to the pole post 410, and a part of the first expansion alloy layer is connected to the insulating element 620.

[0059] It is understandable that both the first and second expansion alloy layers can expand when heated, but the first expansion alloy layer, which has a larger expansion coefficient, elongates more, while the second expansion alloy layer, which has a smaller expansion coefficient, elongates less.

[0060] In other words, when the temperature changes, the deformation and bending degree of the first expansion alloy layer is greater than that of the second expansion alloy layer. It can be understood that when the temperature is higher than the preset temperature, the first expansion alloy layer, the second expansion alloy layer, and the conductive layer bend and deform along the first direction Z, away from the conductive body 610, thereby disconnecting the deformable piece 500 from the conductive body 610. When the temperature is equal to or lower than the preset temperature, the first expansion alloy layer, the second expansion alloy layer, and the conductive layer bend and deform along the first direction Z, closer to the conductive body 610, thereby electrically connecting the deformable piece 500 to the conductive body 610.

[0061] like Figure 4 and Figure 6 As shown, in some embodiments of this application, the first deformable part 510 is welded to the pole post 410 to ensure the stability of the connection between the first deformable part 510 and the pole post 410, thereby ensuring the stability of the connection between the deformable piece 500 and the pole post 410.

[0062] In addition, in this embodiment, the conductive body 610 is provided with a mounting groove on the side facing the pole post 410 along the first direction Z. The insulating member 620 is partially housed in the mounting groove and connected to the groove wall of the mounting groove. The insulating member 620 protrudes at least partially from the mounting groove along the first direction Z.

[0063] The insulating component 620 can be connected to the wall of the mounting groove by any of the following methods: snap-fit, adhesive, or threaded connection. The specific settings can be configured according to the actual situation to improve the stability of the connection between the insulating component 620 and the conductive body 610.

[0064] Secondly, this application provides a battery pack that includes the individual battery cells in any of the above embodiments.

[0065] It is understood that the battery pack has the beneficial effects of the individual cells in any of the above embodiments, which will not be elaborated here.

[0066] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limitations; therefore, other examples of exemplary embodiments may have different values.

[0067] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0068] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this 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 modifications and improvements all fall within the protection scope of this application.

Claims

1. A single-cell battery having a first orientation (Z), characterized in that, include: Casing (100) The electrode assembly (200) is housed within the housing (100); The top cover plate (300) is connected to one end of the housing (100) along the first direction (Z); The pole post (410) is inserted through the top cover plate (300). The deformable sheet (500) is a temperature-sensitive deformable sheet. The deformable sheet (500) is located on the side of the pole post (410) away from the electrode assembly (200). The deformable sheet (500) includes a first deformable part (510) and a second deformable part (520) that are connected to each other. The first deformable part (510) is fixedly connected to the pole post (410), and the second deformable part (520) is arranged around the first deformable part (510). A conductive element (600) is located on the side of the deformable piece (500) facing away from the electrode assembly (200) along the first direction (Z). The conductive element (600) includes a conductive body (610) connected along the first direction (Z) and an insulating element (620). The insulating element (620) is fixedly connected to the first deformable part (510), and the second deformable part (520) is connected to the conductive body (610). The second deformable part (520) is configured to separate from the conductive body (610) when the temperature of the pole piece (410) exceeds a preset temperature.

2. The single-cell battery according to claim 1, characterized in that, The conductive body (610) is disposed around the insulating member (620), a portion of the second deformable portion (520) near the first deformable portion (510) is connected to the insulating member (620), and a portion of the second deformable portion (520) away from the first deformable portion (510) abuts against the conductive body (610).

3. The single-cell battery according to claim 2, characterized in that, Along the first direction (Z), the conductive element (600) has a first end (630) and a second end (640) disposed opposite to each other, the second end (640) being located on the side away from the pole (410), the cross-sectional area of ​​the conductive element (600) being gradually reduced from the second end (640) to near the first end (630), the insulating element (620) being located at the first end (630), and the first end (630) being fixedly connected to the first deformable part (510).

4. The single-cell battery according to claim 3, characterized in that, The single cell also has a second direction (X) perpendicular to the first direction (Z), and the diameter of the insulating member (620) gradually decreases from the second end (640) to the first end (630) along the first direction (Z). The maximum diameter of the insulating member (620) along the second direction (X) is greater than the diameter of the first deformed part (510) along the second direction (X).

5. The single-cell battery according to claim 1, characterized in that, The single cell also includes a fixing part (420) fixedly connected to the electrode post (410). The fixing part (420) is located on the side of the top cover plate (300) facing away from the electrode assembly (200) along the first direction (Z), and the fixing part (420) is arranged around the electrode post (410). The second deformation part (520) is configured to separate from the conductive body (610) when the temperature of the electrode post (410) exceeds a preset temperature, and the second deformation part (520) is connected to the fixing part (420).

6. The single-cell battery according to claim 5, characterized in that, The single cell also has a second direction (X) perpendicular to the first direction (Z), and the diameter of the second deformed part (520) along the second direction (X) is greater than the maximum diameter of the conductive element (600) along the second direction (X).

7. The single-cell battery according to claim 5, characterized in that, The second deformation portion (520) is configured to separate from the conductive body (610) when the temperature of the pole (410) exceeds a preset temperature, and a portion of the second deformation portion (520) near the first deformation portion (510) is connected to the pole (410).

8. The single-cell battery according to any one of claims 1 to 7, characterized in that, The thickness of the second deformed portion (520) along the first direction (Z) is less than the thickness of the insulating member (620) along the first direction (Z).

9. The single-cell battery according to any one of claims 1 to 7, characterized in that, The second deformable portion (520) is connected to the first deformable portion (510) to form a groove. The groove is located on the side away from the pole post (410) along the first direction (Z), and the groove is recessed along the first direction (Z) towards the electrode assembly (200).

10. A battery pack, characterized in that, The single-cell battery includes any one of claims 1 to 9.

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