Top cover assembly, battery monomer, battery and electric device

Abstract

The utility model relates to a top cover assembly and a battery monomer, the top cover assembly comprises a top cover sheet, a pole, an insulation assembly and an electrochromic film, and the electrochromic film is pasted on the outer surface of the top cover sheet and is conductively connected with the top cover sheet. The top cover piece and the shell are not electrified under normal conditions, so that the electrochromic film presents an initial color. And when the insulation assembly fails, the top cover plate is conducted with the pole, so that the top cover plate and the shell are electrically connected with the negative tab of the battery cell assembly through the pole. At the moment, lithium ions are more easily embedded into the shell, so that the shell is subjected to electrochemical corrosion. Meanwhile, as the top cover plate is negatively charged, the color of the electrochromic film is changed. In other words, once the risk that the shell is corroded occurs, the electrochromic film can prompt the risk through color change, and therefore measures can be taken conveniently and timely to avoid more serious consequences caused by aggravation of corrosion. In addition, the utility model also provides a battery and an electric device.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy, and in particular to a top cover assembly, a battery cell, a battery and an electric device. Background Art

[0002] Aluminum shells are widely used in lithium-ion batteries due to their advantages such as light weight, low cost and high safety. The lithium embedding potential of aluminum shells is higher, so power battery manufacturers generally wrap a sealing rubber ring on the outside of the pole to isolate the pole and the aluminum shell to prevent corrosion of the aluminum shell. However, during production and use, the sealing rubber ring may be damaged, causing the negative pole and the aluminum shell to be conductive, thereby making the aluminum shell charged. In this way, lithium ions are more easily embedded in the aluminum shell to form an alloy, causing electrochemical corrosion of the aluminum shell. Over time, the corrosion process will continue. Moreover, the process of electrochemical corrosion of the aluminum shell is difficult to detect, and the final result may be serious problems such as electrolyte leakage due to increased corrosion. Utility Model Content

[0003] Based on this, it is necessary to provide a top cover assembly and a battery cell that can promptly indicate the corrosion risk of the shell in order to address the above-mentioned problem.

[0004] A top cover assembly includes a top cover sheet, a pole, an insulating assembly and an electrochromic film, wherein the top cover sheet has an outer surface and an inner surface on both sides in the thickness direction, the top cover sheet is provided with a mounting hole which passes through in the thickness direction, the pole is passed through the mounting hole, the insulating assembly is arranged between the pole and the top cover sheet to insulate the pole from the top cover sheet, and the electrochromic film is attached to the outer surface of the top cover sheet and is conductively connected to the top cover sheet.

[0005] In one embodiment, the electrochromic film is annular and is arranged along the circumference of the pole.

[0006] In one embodiment, a crimping ring protruding outward is formed at one end of the pole, and the crimping ring presses the electrochromic film against the outer surface of the top cover sheet and exposes the side of the electrochromic film, and the crimping ring and the electrochromic film are separated by the insulating component.

[0007] In one embodiment, an annular step is formed on the edge of the crimping ring facing the outer surface of the top cover sheet, and the electrochromic film is accommodated in an accommodating space enclosed by the annular step and the outer surface of the top cover sheet.

[0008] In one of the embodiments, the pole is provided with a liquid injection hole penetrating along the thickness direction.

[0009] In one embodiment, the electrochromic film is a tungsten trioxide film, a nickel oxide film, a metal phthalocyanine film, a viologen compound film, a tetrathiafulvalene film or a conductive polymer film.

[0010] In one embodiment, the electrochromic film is an ethyl viologen-based organic film.

[0011] A battery cell, comprising:

[0012] A shell having at least one end open;

[0013] A battery cell assembly housed in the housing;

[0014] As in any one of the above preferred embodiments, the top cover assembly covers the opening at one end of the shell, and the pole is electrically connected to the negative pole ear of the battery cell assembly.

[0015] The above-mentioned top cover assembly and battery cell, top cover sheet and shell are not charged under normal circumstances, so the electrochromic film shows the initial color. When the insulating component fails, the top cover sheet is connected to the pole, so the top cover sheet and the shell will be electrically connected to the negative pole ear of the battery cell assembly through the pole. At this time, lithium ions are more easily embedded in the shell, causing electrochemical corrosion of the shell. At the same time, since the top cover sheet is negatively charged, the electrochromic film will show color changes. In other words, once the risk of corrosion of the shell occurs, the electrochromic film can indicate the risk through color changes, so that timely measures can be taken to avoid more serious consequences due to increased corrosion.

[0016] In addition, the utility model also provides a battery and an electricity-using device.

[0017] A battery comprises a plurality of battery cells as described in the above preferred embodiments.

[0018] An electrical device comprises the battery monomer as described in the above preferred embodiment or the battery as described in the above preferred embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 This is a schematic diagram of the structure of a battery cell in a preferred embodiment of the utility model;

[0021] Figure 2 for Figure 1An enlarged schematic diagram of a local A in the battery cell shown;

[0022] Figure 3 for Figure 1 A cross-sectional view of the top cover assembly in the battery cell is shown. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0026] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0028] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0029] The utility model discloses an electric device, a battery and a battery cell. The electric device includes the battery or the battery cell, and can be provided with electric energy by the battery or the battery cell. The electric device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, an energy storage device, an amusement equipment, an elevator and a lifting device, etc. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy or an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator and an electric planer, etc. The energy storage device can be an energy storage wall, a base station energy storage, a container energy storage, etc. The amusement equipment can be a carousel, a jumping machine, etc. This application does not impose any special restrictions on the above-mentioned electrical devices.

[0030] The above-mentioned battery can be a battery pack or a battery module. When the above-mentioned battery is a battery pack, the battery pack specifically includes a battery management system (BMS) and a plurality of the above-mentioned battery cells. The plurality of battery cells can be electrically connected in series, in parallel, or in a mixture of series and parallel, and communicated with the battery management system to form a battery pack, and the above-mentioned battery management system controls and monitors the working status of each battery cell. In addition, the plurality of battery cells can also be first connected in series and / or in parallel, and form a battery module with the module management system, and then the plurality of battery modules are electrically connected in series, in parallel, or in a mixture of series and parallel, and together with the battery management system form a battery pack.

[0031] The battery pack or battery module may be mounted on a supporting structure such as a box, a frame, or a bracket, and the battery cells and the battery management system may be electrically connected via a busbar. The battery cells may be lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, and their outer contours may be cylindrical, flat, rectangular, or other shapes, but are not limited thereto. Specifically, in the present embodiment, the battery cells are lithium-ion prismatic batteries.

[0032] See also Figure 1 The battery cell 10 in the preferred embodiment of the present invention includes a top cover assembly 100, a shell 200 and a battery cell assembly (not shown).

[0033] The housing 200 is a hollow structure, and has a receiving space for accommodating the battery cell assembly, electrolyte and other components. The housing 200 is preferably an aluminum housing because of its advantages of light weight, low cost and high safety. An opening (not shown) is formed at at least one end of the housing 200, and the battery cell assembly can be loaded into the housing 200 through the opening of the housing 200.

[0034] The battery cell assembly is the core component of the battery cell 10 and is housed in the housing 200. The battery cell assembly has a positive ear (not marked in the figure) and a negative ear (not marked in the figure), and the positive ear and the negative ear are respectively led out from the positive electrode sheet and the negative electrode sheet. The positive ear and the negative ear can be located at the same end of the battery cell assembly or at opposite ends of the battery cell assembly. For the long strip battery cell assembly in this embodiment, since its end face size is small, the positive ear and the negative ear are distributed at opposite ends of the battery cell assembly.

[0035] The shape of the battery cell assembly matches the housing 200. Specifically, since the battery cell 10 in this embodiment is a square battery, the outer contour of the housing 200 is a rectangular parallelepiped, so the battery cell assembly is also a rectangular parallelepiped. In addition, since the positive and negative tabs of the battery cell assembly are located at opposite ends of the battery cell assembly, openings are formed at both ends of the housing 200 to facilitate the positive and negative tabs to be led out respectively.

[0036] Please also read Figure 2 and Figure 3 The top cover assembly 100 includes a top cover sheet 110 , a pole 120 , an insulating assembly 130 and an electrochromic film 140 .

[0037] The top cover sheet 110 is generally formed of metal, which can be aluminum or stainless steel. The top cover sheet 110 has an outer surface and an inner surface on both sides of the thickness direction, respectively, and the outer surface and the inner surface refer to the surface facing the outside and the inside of the housing 200 when the top cover assembly 100 is installed in the housing 200. The top cover sheet 110 is provided with a mounting hole (not marked in the figure) that passes through in the thickness direction, and the pole 120 is inserted into the mounting hole.

[0038] The pole 120 can be formed of a metal material with good conductivity such as copper and aluminum, and can be installed in the mounting hole by riveting. Specifically, in the present embodiment, the pole 120 is provided with a liquid injection hole 121 that penetrates along the thickness direction. The electrolyte can be injected into the shell 200 through the liquid injection hole 121, and the liquid injection hole 121 can be sealed by welding the cover plate and inserting the sealing plug after the liquid injection is completed. In this way, there is no need to open another hole on the top cover sheet 110, which helps to improve the structural strength of the top cover sheet 110.

[0039] The insulating assembly 130 is disposed between the pole 120 and the top cover sheet 110 to insulate the pole 120 from the top cover sheet 110. Specifically, the insulating assembly 130 generally includes two parts, the lower part is the lower plastic 132, which can form insulation between the pole 120 and the inner surface of the top cover sheet 110, and the upper part is the sealing rubber ring 131, which can form insulation between the pole 120 and the outer surface of the top cover sheet 110, and can form a seal between the pole 120 and the inner wall of the mounting hole.

[0040] The top cover assembly 100 covers the opening at one end of the shell 200, and the pole 120 is electrically connected to the negative ear of the battery cell assembly. The top cover sheet 110 can be connected to the opening edge of the shell 200 by welding, so as to fix the top cover assembly 110 to the opening of the shell 200. Since the pole 120 is electrically connected to the negative ear of the battery cell assembly, the pole 120 will serve as the negative pole of the battery cell 10. In the case where both ends of the shell 200 are open, the opening at the other end can be covered with an ordinary top cover, so as to form a relatively closed environment inside the shell 200 to isolate the battery cell assembly from the external environment. Compared with the top cover assembly 100, the above-mentioned ordinary top cover does not include the electrochromic film 140, and a positive pole is provided thereon for electrically connecting to the positive ear of the battery cell assembly.

[0041] Furthermore, the electrochromic film 140 is attached to the outer surface of the top cover sheet 110 and is electrically connected to the top cover sheet 110. The electrochromic film 140 has an initial color, such as white, transparent, etc. When the electrochromic film 140 is powered on, the color changes from white or transparent to blue, purple, etc.

[0042] Since the insulating component 130 insulates the pole 120 from the top cover sheet 110, the top cover sheet 110 and the shell are not charged under normal circumstances, so the electrochromic film 140 attached to the top cover sheet 110 presents the initial color. When the insulating component 130 fails, the top cover sheet 110 and the pole 120 will be connected, so the top cover sheet 110 and the shell 200 will also be electrically connected to the negative electrode ear of the battery cell assembly through the pole 120. At this time, the shell 200 is negatively charged, and lithium ions are more easily embedded in the shell 200, resulting in electrochemical corrosion of the shell 200.

[0043] At the same time, the top cover sheet 110 will also be negatively charged, so the electrochromic film 140 attached to the top cover sheet 110 will be energized and change color. In other words, once the risk of corrosion of the housing 200 occurs, the electrochromic film 140 can indicate the risk through color change, so as to facilitate timely measures to avoid more serious consequences due to increased corrosion.

[0044] The electrochromic film 140 can be formed of common electrochromic materials. For example, the electrochromic film 140 can be any one of tungsten trioxide film, nickel oxide film, metal phthalocyanine film, viologen compound film, tetrathiafulvalene film or conductive polymer film.

[0045] It should be noted that electrochromic materials generally have poor viscosity and are difficult to form into films. Therefore, in order to obtain an electrochromic film 140 that meets the requirements for strength and ductility, polymers such as polyacrylonitrile or polypropylene are generally mixed into the corresponding electrochromic material to facilitate film formation.

[0046] Preferably, in the present embodiment, the electrochromic film 140 is an ethyl viologen organic film. Under the action of an electric field, the ethyl viologen organic film can be transformed from colorless (transparent) to blue, with obvious color contrast, which is easy to identify. Moreover, the ethyl viologen organic film has a short color change response time, and the color change usually occurs within 20 seconds of power-on. After the electric field is removed, the ethyl viologen organic film can also be restored from blue to the initial color, so it can be reused.

[0047] During the battery manufacturing process, before the top cover sheet 110 is welded to the shell 200, if the negative pole in a battery cell 10 is folded and connected to the shell 200, the electrochromic film 140 will also change color. With the help of this visual response, it is convenient for employees to screen abnormal situations in time and improve the folding state of the negative pole ear. When the state of the negative pole ear is improved, the shell 200 is discharged and the electrochromic film 140 can be restored to its original color. The battery cell 10 can be offline as a normal product after the above treatment, thereby improving the yield of battery production.

[0048] In this embodiment, the electrochromic film 140 is annular and is disposed along the circumference of the pole 120. In actual application scenarios of the battery cell 10, the pole 120 is generally exposed. Therefore, disposing the electrochromic film 140 along the circumference of the pole 120 can make the electrochromic film 140 easier to detect when it changes color.

[0049] Furthermore, in the present embodiment, a crimping ring 122 protruding outward is formed at one end of the pole 120 , and the crimping ring 122 presses the electrochromic film 140 against the outer surface of the top cover sheet 110 and exposes the side of the electrochromic film 140 , and the crimping ring 122 and the electrochromic film 140 are separated by an insulating component 130 .

[0050] Since the electrochromic film 140 is only exposed on the side, the color of the circle around the pole 120 will change when the insulating assembly 130 fails. In addition, since the crimping ring 122 covers the electrochromic film 140, it can provide protection for the electrochromic film 140, thereby preventing the electrochromic film 140 from being worn or falling off from the top cover sheet 110, thereby improving the reliability of the top cover assembly 100.

[0051] Furthermore, in this embodiment, an annular step (not shown) is formed on the edge of the crimping ring 122 facing the outer surface of the top cover sheet 110 , and the electrochromic film 140 is accommodated in the accommodation space enclosed by the annular step and the outer surface of the top cover sheet 110 .

[0052] The receiving space enclosed by the annular step and the outer surface of the top cover sheet 110 extends along the circumference of the pole 120, and an opening is formed on its side. The electrochromic film 140 can be well limited in the receiving space, and the opening of the receiving space can expose the side of the electrochromic film 140. Moreover, the provision of the annular step can better accommodate the electrochromic film 140, thereby avoiding the gap between the crimping ring 122 and the outer surface of the top cover sheet 110 being too large due to the electrochromic film 140 occupying the position, which is conducive to improving the sealing performance between the pole 120 and the top cover sheet 110.

[0053] The above-mentioned top cover assembly 100 and battery cell 10, top cover sheet 110 and shell 200 are not charged under normal circumstances, so the electrochromic film 140 presents the initial color. When the insulating assembly 130 fails, the top cover sheet 110 and the pole 120 are conductive, so the top cover sheet 110 and the shell 200 will be electrically connected to the negative pole ear of the battery cell assembly through the pole 120. At this time, lithium ions are more easily embedded in the shell 200, causing electrochemical corrosion of the shell 200. At the same time, since the top cover sheet 110 is negatively charged, the electrochromic film 140 will show a color change. In other words, once the risk of corrosion of the shell 200 occurs, the electrochromic film 140 can indicate the risk through color changes, so that timely measures can be taken to avoid more serious consequences due to increased corrosion.

[0054] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0055] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A top cover assembly, characterized in that: It includes a top cover sheet, a pole, an insulating component and an electrochromic film. The top cover sheet has an outer surface and an inner surface on both sides in the thickness direction. The top cover sheet is provided with a mounting hole that passes through along the thickness direction. The pole is inserted into the mounting hole. The insulating component is arranged between the pole and the top cover sheet to insulate the pole from the top cover sheet. The electrochromic film is attached to the outer surface of the top cover sheet and is conductively connected to the top cover sheet.

2. The top cover assembly according to claim 1, characterized in that: The electrochromic film is annular and arranged along the circumference of the pole.

3. The top cover assembly according to claim 2, characterized in that: A crimping ring protruding outward is formed at one end of the pole, and the crimping ring presses the electrochromic film against the outer surface of the top cover sheet and exposes the side of the electrochromic film, and the crimping ring and the electrochromic film are separated by the insulating component.

4. The top cover assembly according to claim 3, characterized in that: An annular step is formed on the edge of the crimping ring facing the outer surface of the top cover sheet, and the electrochromic film is accommodated in an accommodating space surrounded by the annular step and the outer surface of the top cover sheet.

5. The top cover assembly according to claim 1, characterized in that: The pole is provided with a liquid injection hole penetrating along the thickness direction.

6. The top cover assembly according to claim 1, characterized in that: The electrochromic film is a tungsten trioxide film, a nickel oxide film, a metal phthalocyanine film, a viologene compound film, a tetrathiafulvalene film or a conductive polymer film.

7. The top cover assembly according to claim 6, characterized in that: The electrochromic film is an ethyl viologen-based organic film.

8. A battery cell, characterized in that: include: A shell having at least one end open; A battery cell assembly housed in the housing; As described in any one of claims 1 to 7 above, the top cover assembly covers the opening at one end of the shell, and the pole is electrically connected to the negative electrode ear of the battery cell assembly.

9. A battery, characterized in that: The invention comprises a plurality of battery cells as claimed in claim 8.

10. An electrical device, characterized in that: The invention comprises a battery cell as claimed in claim 8 or a battery as claimed in claim 9.

Images