CN220066052U

CN220066052U - Battery cell

Info

Publication number: CN220066052U
Application number: CN202321224196.3U
Authority: CN
Inventors: 李树军; 张庆; 杨维领; 何绪苗
Original assignee: Liyang Zhongke Haina Technology Co ltd
Current assignee: Liyang Zhongke Haina Technology Co ltd
Priority date: 2023-05-19
Filing date: 2023-05-19
Publication date: 2023-11-21
Anticipated expiration: 2033-05-19

Abstract

The utility model belongs to the technical field of batteries, and discloses a battery. The battery is provided with two polar posts, one of which is a positive polar post and the other of which is a negative polar post, and is characterized in that the battery comprises at least one top cover, and at least one polar post is arranged on the top cover. At least one pole of the battery is provided with a conductive piece, and the pole provided with the conductive piece is connected with the top cover in an insulating way. The conductive piece is provided with a connecting end and a free end, the connecting end is in conductive connection with the pole, the free end extends towards the direction close to the top cover and is arranged at intervals with the top cover, the conductive piece can deform when being heated, the free end can be in contact with the top cover after deformation, and when the free end is in contact with the top cover, the battery is in external short circuit. The battery can quickly release the energy in the battery before thermal runaway, so that the safety problems such as thermal runaway caused by the temperature rise of the battery cell are avoided.

Description

Battery cell

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery.

Background

The secondary battery has a wide operating temperature range and a long service life due to good charge and discharge performance, and is widely used in various fields. At the same time, the safety performance is increasingly paid attention to. In the use process of the secondary battery, the problems that lithium (sodium) dendrites are separated out from the negative electrode to puncture the diaphragm, the diaphragm is melted or contracted and the like can occur. These problems easily cause short circuits, raise the internal temperature of the battery, and when the temperature rises to about 100 ℃, the SEI film (solid electrolyte interface film) starts to dissolve, further causing the formation of chain-type heat release inside the battery, causing thermal runaway, and eventually causing safety problems such as ignition of the battery.

At present, solutions to thermal runaway are mostly initiated from structural and material aspects. The measures in terms of materials, such as adding flame retardant into a heat-resistant PP material diaphragm or electrolyte; the structure is used for realizing the fusing of the anode and the cathode under a certain pressure condition. The material changes and structural design are not effective in preventing safety problems. For example, the separator has an increased resistance to high temperatures, but still has its limits, and beyond the temperature range there is still a risk of shrinkage leading to short circuits; the introduction of the flame retardant reduces the conductivity and mobility of lithium ions and weakens the electrochemical performance of the battery. The structural design not only increases the cost but also cannot completely block the thermal runaway. The measures can only reduce the intensity of thermal runaway to a certain extent, so that the battery can reach the safe use degree, and the safety problem caused by the thermal runaway cannot be completely solved.

Therefore, there is a need to provide a battery to solve the above problems.

Disclosure of Invention

The utility model aims to provide a battery which can quickly release energy in the battery before thermal runaway, so that safety problems such as thermal runaway caused by the increase of the temperature of a battery cell are avoided.

To achieve the purpose, the utility model adopts the following technical scheme:

the battery is provided with two polar posts, wherein one of the two polar posts is a positive polar post, the other is a negative polar post, the battery comprises at least one top cover, and at least one polar post is arranged on the top cover;

at least one pole of the battery is provided with a conductive piece, and the pole provided with the conductive piece is connected with the top cover in an insulating way;

the conductive piece is provided with a connecting end and a free end, the connecting end is in conductive connection with the pole, the free end extends towards the direction close to the top cover and is arranged with the top cover at intervals, the conductive piece can be deformed when being heated, the free end can be in contact with the top cover after deformation, and when the free end is in contact with the top cover, the battery is in external short circuit.

Optionally, the conductive member includes a first metal sheet and a second metal sheet stacked in a vertical direction, and an expansion coefficient of the first metal sheet is smaller than an expansion coefficient of the second metal sheet.

Optionally, the first metal sheet is located on a side close to the top cover.

Optionally, an insulating sheet is disposed between the first metal sheet and the top cover, one end of the insulating sheet is connected with the first metal sheet, and the other end of the insulating sheet is abutted to the top cover.

Optionally, the first metal sheet and the second metal sheet are joined by rolling.

Optionally, the ratio of the thicknesses of the second metal sheet and the first metal sheet is 1.5 to 5.

Optionally, the distance from the free end of the conductive piece to the top cover is 0.2-2.0 mm.

Optionally, the connection end and the pole are welded.

Optionally, a plurality of conductive members are provided, and a plurality of conductive members are provided along the circumferential direction of the pole.

Optionally, an insulating member is sleeved on the periphery of the pole provided with the conductive member.

The beneficial effects are that:

according to the battery provided by the utility model, the conductive piece is arranged on the pole, and the conductive piece has the characteristic of thermal deformation. Under normal conditions, the conductive piece is not contacted with the top cover, so that the conductive piece and the top cover cannot conduct electricity, when the internal temperature of the battery cell reaches the preset temperature, the conductive piece structure deforms and the top cover contacts, so that the conductive piece is connected with the top cover in a conductive way, the battery is in an external short circuit, and the electric quantity of the battery is rapidly released, and therefore, the occurrence of safety problems such as thermal runaway and the like caused by the temperature rise of the battery cell is avoided.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following description will briefly explain the drawings needed in the description of the embodiments of the present utility model, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the contents of the embodiments of the present utility model and these drawings without inventive effort for those skilled in the art.

Fig. 1 is a schematic view of a partial structure of a battery according to the present utility model;

fig. 2 is a schematic diagram of a partial structure of a battery according to the present utility model;

fig. 3 is a side view of a partial structure of a battery provided by the present utility model (a conductive member is provided on a positive electrode post, and a conductive member is not provided on a negative electrode post);

fig. 4 is a side view of a partial structure of a battery provided by the present utility model (no conductive member is provided on the positive electrode post, and a conductive member is provided on the negative electrode post);

fig. 5 is a side view of a partial structure of a battery provided by the present utility model (conductive members are provided on both the positive electrode post and the negative electrode post);

fig. 6 is a schematic view of a partial structure of a battery provided by the present utility model (conductive members are disposed on both the positive electrode post and the negative electrode post);

fig. 7 is a schematic view of a partial structure of a battery (a pole is disposed on a top cover) according to the present utility model.

In the figure:

100. a top cover; 110. a positive electrode post; 120. a negative electrode column; 200. a conductive member; 210. a first metal sheet; 220. a second metal sheet; 300. an insulating sheet; 400. an insulating member.

Detailed Description

The following description of the embodiments of the present utility model will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first location" and "second location" are two distinct locations and wherein the first feature is "above," "over" and "over" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is level above the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model.

Referring to fig. 1 and 2, the present embodiment provides a battery having two poles, one of which is a positive pole 110 and the other of which is a negative pole 120. Further, the battery includes at least one top cap 100, and at least one electrode post is disposed on the top cap 100. At least one of the poles of the battery is provided with a conductive member 200, and the pole provided with the conductive member 200 is connected with the top cover 100 in an insulating manner. The conductive member 200 has a connection end and a free end, the connection end is electrically connected with the pole, the free end extends to a direction close to the top cover 100 and is arranged at intervals with the top cover 100, the conductive member 200 can be deformed when being heated, the free end can be contacted with the top cover 100 after deformation, and when the free end is contacted with the top cover 100, external short circuit occurs to the battery.

In the above battery, the conductive member 200 is provided on the post, so that the conductive member 200 has a thermal deformation characteristic. Under normal conditions, the conductive piece 200 and the top cover 100 are not contacted, so that the conductive piece 200 and the top cover 100 are not conductive, when the internal temperature of the battery cell reaches the preset temperature, the structure of the conductive piece 200 is deformed and contacts with the top cover 100, so that the conductive piece 200 is in conductive connection with the top cover 100, the battery is subjected to external short circuit, and the electric quantity of the battery is rapidly released, and therefore, the occurrence of safety problems such as thermal runaway and the like caused by the temperature rise of the battery cell is avoided.

It is understood that the preset temperature is less than the temperature at which thermal runaway of the battery cells occurs, and the specific size is set according to the characteristics of the battery. The battery may be a cylindrical battery or a square battery, and the number of the top cover 100 may be one or two.

Further, the conductive member 200 includes a first metal sheet 210 and a second metal sheet 220 disposed in a vertical direction, and the expansion coefficient of the first metal sheet 210 is smaller than that of the second metal sheet 220. Illustratively, the first metal sheet 210 may be nickel or iron or the like having a small expansion coefficient, and the second metal sheet 220 may be copper having a large expansion coefficient. After the temperature rises, the metal sheet with a large expansion coefficient is deformed greatly, and the metal sheet with a small expansion coefficient is deformed little. Since the second metal sheet 220 has a larger tensile deformation than the first metal sheet 210, the conductive member 200 is bent upward by heat to contact the top cover 100, thereby realizing an external positive-negative short circuit. The electric energy in the battery is rapidly released through the external short circuit, and the electric quantity is rapidly reduced. After the electricity consumption, the energy supply is lost in the battery, and the heat release is stopped, so that the safety problem caused by thermal runaway is avoided.

Further, the first metal sheet 210 is located at a side close to the top cover 100. Since the first metal sheet 210 has a small expansion coefficient, the free end is bent toward the top cover 100 after the conductive member 200 is deformed by heat, and the conductive member 200 is in contact with the top cover 100.

It is understood that the conductive member 200 may further include a third metal sheet, a fourth metal sheet, a fifth metal sheet, etc., where a plurality of metal sheets are stacked and the expansion coefficients of the plurality of metal sheets gradually decrease from the bottom of the pole toward the top cover 100. The number of the metal sheets is set according to the use requirement, and is not particularly limited herein.

Further, an insulating sheet 300 is provided between the first metal sheet 210 and the top cover 100, and one end of the insulating sheet 300 is connected to the first metal sheet 210 and the other end is abutted against the top cover 100. The insulating sheet 300 can keep the distance between the conductive member 200 and the top cover 100 fixed, and avoid the change of the distance between the conductive member 200 and the top cover 100 caused by vibration or other factors during use. As can be appreciated, before the preset temperature, the increase of the distance between the conductive element 200 and the top cover 100 will cause the conductive element 200 to still not contact with the top cover 100 after the cell reaches the preset temperature, and the energy releasing function of the conductive element 200 is disabled; and a decrease in the distance between the conductive member 200 and the top cap 100 will cause an external short circuit of the battery before reaching a preset temperature. Illustratively, the material of the insulating sheet 300 may be insulating plastic. In the present embodiment, the insulating sheet 300 is disposed in the vertical direction, and in other embodiments, the insulating sheet 300 may be disposed obliquely as needed. In this embodiment, one end of the insulating sheet 300 is fixedly connected to the first metal sheet 210, and the other end is abutted to the top cover 100 without being fixedly connected to avoid affecting the deformation of the conductive member 200. In other embodiments, one end of the insulating sheet 300 may be fixedly connected to the top cover 100, and the other end may abut against the first metal sheet 210 without being fixedly connected.

Further, at normal temperature, the first metal sheet 210 and the second metal sheet 220 have the same width and length dimensions, and the length dimension ranges from 5 to 100mm and the width dimension ranges from 5 to 30mm by rolling and bonding, and specifically can be adjusted according to the battery capacity. By adopting such a connection, it is possible to avoid separation of the first metal sheet 210 and the second metal sheet 220 when they are deformed.

Further, the ratio of the thicknesses of the second metal sheet 220 and the first metal sheet 210 is 1.5 to 5, and may be 1.5, 3, 4.5, 5, or the like, for example. The metal sheet with larger expansion coefficient is positioned on the lower layer, and the thickness is thicker, so that the metal sheet is ensured to be bent upwards by enough deformation amount during deformation. The thickness of the second metal sheet 210 with a larger expansion coefficient can be properly increased to increase the overall deformation of the conductive member 200, so that the first metal sheet 210 contacts the top cover 100 earlier, if an external short circuit is required to occur at a lower temperature. The thickness of the first and second metal sheets 210 and 220 is in the range of 0.5 to 2.0mm.

Further, the distance from the free end of the conductive member 200 to the top cover 100 is 0.2 to 2.0mm, and may be, for example, 0.2mm, 0.5mm, 1.0mm, 1.5mm, 2.0mm, or the like, which may be adjusted according to a predetermined temperature requirement.

Further, the connection end of the conductive member 200 is welded to the post. And a welding connection mode is adopted, so that the connection is convenient and reliable.

Further, the plurality of conductive members 200 are provided, and the plurality of conductive members 200 are provided along the circumferential direction of the pole. In this embodiment, the pole under the top cover 100 is prismatic, and one conductive member 200 is connected to each surface in the circumferential direction. In other embodiments, the number of conductive elements 200 may be two, five, ten, etc. The increased number of conductive members 200 can increase the overcurrent capability at the time of external short circuit, or can increase the overcurrent capability by increasing the cross-sectional area of the metal sheet.

Further, an insulator 400 is provided around the outer circumference of the pole provided with the conductive member 200.

The present utility model is described in further detail below:

example 1

Referring to fig. 3, in the present embodiment, the conductive member 200 is disposed on the positive electrode post 110, the conductive member 200 is not disposed on the negative electrode post 120, the negative electrode post 120 is electrically connected to the top cover 100, and the positive electrode post 110 is electrically connected to the top cover 100 in an insulating manner. When the conductive member 200 is deformed by heat and contacts the top cap 100, the conductive connection of the conductive member 200, the top cap 100 and the negative electrode post 120 is shorted.

Example two

Referring to fig. 4, in the present embodiment, the conductive member 200 is disposed on the negative electrode post 120, the conductive member 200 is not disposed on the positive electrode post 110, the negative electrode post 120 is connected to the top cover 100 in an insulating manner, and the positive electrode post 110 is connected to the top cover 100 in an electrically conductive manner. When the conductive member 200 is deformed by heat and contacts the top cap 100, the conductive connection of the conductive member 200, the top cap 100 and the positive electrode post 110 is shorted.

Example III

Referring to fig. 5 and 6, in the present embodiment, conductive members 200 are provided on the positive electrode post 110 and the negative electrode post 120, and the positive electrode post 110 and the negative electrode post 120 are connected with the top cover 100 in an insulating manner. When both conductive members 200 are deformed by heat and contact with the top cover 100, the top cover 100 electrically connects the two conductive members 200 to generate an external short circuit.

Example IV

Referring to fig. 7, in the present embodiment, the battery has two top caps 100, and one terminal is provided on each top cap 100. One of the poles is provided with a conductive member 200, the pole provided with the conductive member 200 is connected with the top cover 100 in an insulating manner, and the pole not provided with the conductive member 200 is connected with the top cover 100 in an electrically conductive manner. When the conductive member 200 is deformed by heat and contacts the top cover 100, the conductive member 200, the top cover 100, the battery case, and the terminal conductive connection of the unconnected conductive member are shorted.

Example five

In this embodiment, the battery has two top covers 100, and one pole is provided on each top cover 100. Each pole is provided with a conductive member 200, and each pole is connected with the top cover 100 in an insulating manner. When the conductive member 200 is deformed by heat and contacts the top cover 100, the conductive connection of the conductive member 200, the top cover 100, and the battery case is short-circuited.

It is to be understood that the above examples of the present utility model are provided for clarity of illustration only and are not limiting of the embodiments of the present utility model. Various obvious changes, rearrangements and substitutions can be made by those skilled in the art without departing from the scope of the utility model. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the utility model are desired to be protected by the following claims.

Claims

1. A battery having two poles, one of which is a positive pole (110) and the other of which is a negative pole (120), characterized in that the battery comprises at least one top cover (100), at least one of the poles being provided on the top cover (100);

at least one of the poles of the battery is provided with a conductive piece (200), and the pole provided with the conductive piece (200) is connected with the top cover (100) in an insulating way;

the conductive piece (200) is provided with a connecting end and a free end, the connecting end is in conductive connection with the pole, the free end extends towards the direction close to the top cover (100) and is arranged at intervals with the top cover (100), the conductive piece (200) can be deformed when being heated, the free end can be in contact with the top cover (100) after deformation, and when the free end is in contact with the top cover (100), the battery is in external short circuit.

2. The battery according to claim 1, wherein the conductive member (200) includes a first metal sheet (210) and a second metal sheet (220) stacked in a vertical direction, and wherein a coefficient of expansion of the first metal sheet (210) is smaller than a coefficient of expansion of the second metal sheet (220).

3. The battery according to claim 2, wherein the first metal sheet (210) is located on a side close to the top cover (100).

4. The battery according to claim 2, wherein an insulating sheet (300) is provided between the first metal sheet (210) and the top cover (100), one end of the insulating sheet (300) is connected to the first metal sheet (210), and the other end of the insulating sheet (300) is abutted to the top cover (100).

5. The battery according to claim 2, wherein the first metal sheet (210) and the second metal sheet (220) are joined by rolling.

6. The battery according to claim 2, wherein the ratio of the thickness of the second metal sheet (220) to the first metal sheet (210) is 1.5 to 5.

7. The battery according to any one of claims 1 to 6, wherein the distance from the free end of the conductive member (200) to the top cover (100) is 0.2 to 2.0mm.

8. The battery of any one of claims 1-6, wherein the connection end and the post are welded together.

9. The battery according to any one of claims 1 to 6, wherein a plurality of the conductive members (200) are provided, and a plurality of the conductive members (200) are provided along the circumferential direction of the post.

10. The battery according to any one of claims 1 to 6, wherein an insulating member (400) is provided around the outer circumference of the pole provided with the conductive member (200).