Shell for secondary battery and secondary battery

Abstract

The utility model provides a shell for a secondary battery and the secondary battery. The shell comprises a thermochromism glass shell body, the color of the thermochromic glass shell can be changed according to different heat; and the protective film is arranged on the inner wall of the thermochromic glass shell and is used for preventing the thermochromic glass shell from being corroded by electrolyte. Compared with the prior art, the battery with the thermochromic glass shell provided by the utility model has the advantages that when the battery works to generate heat, different colors can be changed according to different heat generated by each part of the battery; the method is used for solving the problems that complex component equipment needs to be used for monitoring the surface temperature of a battery in the prior art, only point-like monitoring can be carried out on most batteries, and the overall temperature distribution condition of the battery cannot be conveniently and rapidly detected. Therefore, the problems that the internal temperature of the battery cannot be conveniently and rapidly detected and the detection cost cannot be saved at present are solved.

Description

Technical Field

[0001] The utility model relates to the field of secondary batteries, and specifically to a secondary battery housing and a secondary battery Background Art

[0002] In today's rapidly developing technological environment, energy demand continues to rise, with fossil fuels dominating, accounting for up to 80% of energy consumption. While fossil fuels provide the necessary power for the operation of society, at the same time, their consumption has also led to a series of environmental problems, such as global warming, extreme climate events, and deteriorating air quality, which pose a direct threat to human health and ecological security. Therefore, it has become crucial to find and develop clean, renewable energy alternatives.

[0003] In this context, battery technology, especially batteries for energy storage and power, has become a key component in achieving this transformation. The market demand for high energy density and lightweight batteries is becoming increasingly urgent, especially in electric transportation and renewable energy storage. This demand has driven the rapid development and widespread application of high-capacity, new battery technologies. However, these advanced battery systems, especially lithium-ion batteries, are often accompanied by safety risks, mainly due to their insufficient thermal stability when overcharged or other forms of abuse.

[0004] If the heat generated by the battery during the charging and discharging process is not effectively managed, it may cause the internal temperature to be too high, causing the so-called "thermal runaway" phenomenon. This will not only accelerate the degradation of battery performance, but may also trigger the instability of internal chemicals, leading to fire or explosion, which has been confirmed in some publicly reported accidents. At present, the monitoring of battery temperature mainly relies on thermocouples or thermistors that directly measure the surface temperature of the battery, or use infrared thermal imaging technology. These methods have their own advantages and disadvantages: traditional thermistors can only monitor the local temperature of the battery and cannot reflect the overall situation; although infrared thermal imaging can provide comprehensive temperature distribution data, the equipment is expensive and difficult to integrate in some application scenarios.

[0005] In addition, these technologies often fail to respond to microscopic temperature changes inside the battery in real time, especially in large battery packs, where differences in the status of individual cells inside may lead to uneven overall performance and even cause safety hazards. Therefore, the market urgently needs a solution that can accurately monitor battery temperature in real time and is cost-effective and easy to integrate.

[0006] In view of this, it is imperative to develop an innovative, efficient and safe battery temperature monitoring technology. Utility Model Content

[0007] One of the purposes of the utility model is to provide a shell for a secondary battery shell to solve the technical problems that the overall temperature inside the battery is difficult to monitor in real time and the infrared thermal imaging technology for overall monitoring is costly.

[0008] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0009] A secondary battery housing, comprising:

[0010] Thermochromic glass shell; the thermochromic glass shell can change color according to the heat;

[0011] The protective film is arranged on the inner wall of the thermochromic glass shell and is used to prevent the thermochromic glass shell from being corroded by the electrolyte.

[0012] Preferably, the thermochromic glass housing comprises a first glass layer, a second glass layer and a thermochromic polymer layer, and the thermochromic polymer layer is disposed between the first glass layer and the second glass layer.

[0013] Preferably, the first glass layer is a glass layer on the outer side of the battery, the second glass layer is a glass layer close to the battery cell side, and the thickness of the first glass layer is greater than the thickness of the second glass layer.

[0014] Preferably, the thickness of the first glass layer is 3-4 mm; the thickness of the second glass layer is 2-3 mm.

[0015] Preferably, the light transmittance of the first glass layer and the second glass layer are both ≥80%.

[0016] Preferably, the thermochromic polymer layer includes at least one of a thermochromic coating layer and a thermochromic solid particle layer.

[0017] Preferably, the first glass layer and the second glass layer are both organic glass layers.

[0018] Preferably, the thermochromic polymer layer contains thermochromic particles.

[0019] Preferably, the thermochromic particles are metal oxide particles, such as Fe2O3, PbO, HgO, VO2 particles or modified particles thereof.

[0020] Preferably, the thermochromic glass shell is in the shape of a square shell or a cylindrical shell.

[0021] Preferably, the protective film is a PTFE film or a PEEK film.

[0022] Preferably, the protective film is arranged on the inner wall of the thermochromic glass shell by bonding or coating.

[0023] The second object of the utility model is to provide a secondary battery, comprising a shell, a top cover sealed and mounted on the top of the shell, and a battery cell arranged inside the shell, wherein the shell is the shell for the secondary battery mentioned above.

[0024] Preferably, the inner wall of the secondary battery housing is provided with a groove, and the bottom of the top cover is provided with a flange matching with the groove.

[0025] The beneficial effects of the utility model are as follows: the utility model is a secondary battery housing, comprising: a thermochromic glass shell; the thermochromic glass shell can change color according to different heat; a protective film is arranged on the inner wall of the thermochromic glass shell to prevent the thermochromic glass shell from being corroded by the electrolyte. When the battery is working and generating heat, the shell can change color according to the different heat generated by various parts of the battery, which is convenient for direct observation by the naked eye; it can solve the problem that the existing battery surface temperature monitoring requires the use of complex components and equipment, and most of them can only monitor in a point-like manner, and cannot conveniently and quickly detect the overall temperature distribution of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of a battery based on a thermochromic glass shell according to the utility model;

[0027] In the figure: 1-thermochromic glass shell; 2-protective film; 3-top cover; 4-battery cell; 5-groove; 6-flange; 7-ear; 8-liquid injection hole. DETAILED DESCRIPTION

[0028] In order to make the technical solution and advantages of the utility model clearer, the utility model and its beneficial effects will be further described in detail below in combination with specific implementation methods and drawings of the specification, but the implementation methods of the utility model are not limited thereto.

[0029] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "fixed" 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. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The standard parts used in the utility model can all be purchased from the market, and special-shaped parts can be customized according to the instructions and the drawings. The specific connection methods of each part adopt the conventional means such as mature bolts, rivets, welding, etc. in the existing technology. The machinery, parts and equipment all adopt the conventional models in the existing technology, and the circuit connection adopts the conventional connection method in the existing technology, which will not be described in detail here.

[0031] According to the first aspect of the present application, the utility model provides a secondary battery housing, comprising:

[0032] Thermochromic glass housing 1; the thermochromic glass housing 1 can change color according to the heat;

[0033] The protective film 2 is arranged on the inner wall of the thermochromic glass housing 1 to prevent the thermochromic glass housing 1 from being corroded by the electrolyte.

[0034] During the operation of the battery, the battery cell 4 generates heat during the charge and discharge process, and the heat is transferred to the thermochromic glass shell 1. The thermochromic glass shell 1 changes into different colors with the heat, so that the temperature distribution of the battery during operation can be observed with the naked eye, thereby reducing safety hazards.

[0035] In one embodiment of the present application, the thermochromic glass housing 1 includes a first glass layer, a second glass layer, and a thermochromic polymer layer, wherein the thermochromic polymer layer is disposed between the first glass layer and the second glass layer.

[0036] In one embodiment of the present application, the thermochromic glass shell 1 includes a first glass layer and a second glass layer, the thickness of the first glass layer is greater than the second glass layer, the second glass layer is close to the heating cell, the thinner it is, the faster the heat conduction, so that the thermochromic polymer layer develops color faster; the first glass layer with a relatively high thickness can provide rigidity, making the battery less likely to be damaged, and plays a role in protecting the battery. In one embodiment of the present application, the transmittance of the first glass layer and the second glass layer are both ≥80%, and the use of materials with high transmittance can enable users to clearly identify the temperature changes of the battery with the naked eye, thereby improving the safety performance of the battery.

[0037] In one embodiment of the present application, the first glass layer and the second glass layer are both PMMA organic glass layers. They have good optical properties, high transparency, and can withstand outdoor aging. They have good mechanical properties and can resist inorganic acids, alkalis, and greases. Their good light transmittance enables the naked eye to directly observe the temperature changes inside the battery.

[0038] In one embodiment of the present application, the thermochromic polymer layer contains thermochromic particles. From the perspective of thermodynamics, thermochromic materials are divided into reversible thermochromic materials and irreversible thermochromic materials. The present application uses reversible thermochromic materials. When the material is heated to a certain temperature range, the color will change and present a new color. When the temperature returns to the initial temperature, the color will return to the original color. The color change is reversible, and this material can be used repeatedly.

[0039] In one embodiment of the present application, the thermochromic particles are metal oxide particles, such as Fe2O3, PbO, HgO, VO2 particles or modified particles thereof. Of course, other thermochromic particles can also be used as long as the thermochromic requirements are met. Preferably, the present application uses vanadium dioxide (VO2) particles or doped VO2 particles; vanadium dioxide is a transition metal oxide whose optical properties change reversibly with changes in temperature. VO2 can tolerate repeated heating and cooling cycles without being easily damaged. Its phase change temperature is 68°C, and the optical properties before and after the phase change change greatly.

[0040] In one embodiment of the present application, the shape of the thermochromic glass housing 1 is a square housing or a cylindrical housing. That is, the housing of the present application can be used for square shell batteries or cylindrical batteries, and of course can also be used for batteries of other shapes, such as special-shaped batteries.

[0041] In one embodiment of the present application, the protective film 2 is a PTFE film or a PEEK film. Of course, the protective film 2 can also be made of other materials as long as it can meet the requirements of an insulating film resistant to electrolyte corrosion. Preferably, the protective film 2 is a polytetrafluoroethylene film (PTFE). The PTFE film is insoluble in strong acids, strong alkalis and organic solvents and is resistant to corrosion by strong oxidants, which can effectively prevent the electrolyte from corroding the PMMA glass.

[0042] In one embodiment of the present application, the protective film 2 is disposed on the inner wall of the thermochromic glass housing 1 by bonding or coating.

[0043] According to the second aspect of the present application, Figure 1 As shown, the present application provides a secondary battery, including a shell, a top cover 3 sealed and mounted on the top of the shell, and a battery cell 4 arranged inside the shell, and the shell is the above-mentioned shell for the secondary battery. Among them, the pole ear 7 of the battery cell 4 is electrically connected to the top cover 3; the top cover 3 includes 3 top cover pieces, a plastic bracket mounted on the bottom of the top cover 3 pieces, and a positive pole column and a negative pole column mounted on the top cover 3 pieces, and the top cover 3 pieces are provided with a liquid injection hole 8 and an explosion-proof valve.

[0044] The secondary battery may be a lithium-ion battery or a sodium-ion battery, and the size of the housing may be adjusted according to the size of the battery cell 4 .

[0045] In one embodiment of the present application, the inner wall of the secondary battery housing is provided with a groove 5, and the bottom of the top cover 3 is provided with a flange 6 that matches the groove 5. The concave-convex matching structure can seal the top cover 3 and the thermochromic glass housing 1, and glue can be applied therebetween for bonding, and the type of glue can be selected from room temperature vulcanized silicone rubber, organic silica gel, dry glue, UV glue, epoxy glue, etc.; preferably, the glue used in the present application is epoxy resin high temperature resistant ab glue.

[0046] The secondary battery adopts a shell based on a thermochromic glass shell 1. When the battery is working and generating heat, the shell can change colors according to the different heat generated by various parts of the battery, which is convenient for direct observation by the naked eye. It can solve the problem that the existing battery surface temperature monitoring requires the use of complex components and equipment, and most of them can only be monitored in a point-like manner, and cannot quickly and conveniently detect the overall temperature distribution of the battery.

[0047] According to the disclosure and teaching of the above description, the technicians in the field of the utility model can also change and modify the above implementation. Therefore, the utility model is not limited to the above specific implementation, and any obvious improvement, replacement or modification made by the technicians in this field on the basis of the utility model belongs to the protection scope of the utility model. In addition, although some specific terms are used in this specification, these terms are only for the convenience of explanation and do not constitute any limitation to the utility model.

Claims

1. A secondary battery casing, characterized in that: include: Thermochromic glass housing; The thermochromic glass shell can change color according to the heat; A protective film, disposed on the inner wall of the thermochromic glass shell, for preventing the thermochromic glass shell from being corroded by the electrolyte; The thermochromic glass shell comprises a first glass layer, a second glass layer and a thermochromic polymer layer, wherein the thermochromic polymer layer is arranged between the first glass layer and the second glass layer; the thermochromic polymer layer comprises one of a thermochromic coating layer and a thermochromic solid particle layer.

2. The secondary battery casing according to claim 1, wherein: The first glass layer is the glass layer on the outer side of the battery, the second glass layer is the glass layer close to the battery cell side, and the thickness of the first glass layer is greater than the thickness of the second glass layer.

3. The secondary battery casing according to claim 1, wherein: The thickness of the first glass layer is 3-4 mm; the thickness of the second glass layer is 2-3 mm.

4. The secondary battery casing according to claim 1, wherein: The light transmittance of the first glass layer and the second glass layer are both ≥80%.

5. The secondary battery casing according to claim 1, wherein: The shape of the thermochromic glass shell is a square shell or a cylindrical shell.

6. The secondary battery casing according to claim 1, characterized in that: The protective film is arranged on the inner wall of the thermochromic glass shell by bonding or coating.

7. A secondary battery, characterized in that: The invention comprises a shell, a top cover sealed and mounted on the top of the shell, and a battery cell arranged inside the shell, wherein the shell is the shell according to any one of claims 1 to 6.

8. The secondary battery according to claim 7, characterized in that: The inner wall of the shell is provided with a groove, and the bottom of the top cover is provided with a flange matched with the groove.

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