阅读说明：本技术 一种动力电池防爆结构及其动力电池 (Power battery explosion-proof structure and power battery thereof ) 是由 郭彬彬 符远翔 于 2021-03-18 设计创作，主要内容包括：本发明公开了一种动力电池防爆结构及其动力电池。防爆结构包括泄压孔及防爆膜。泄压孔直接在盖板上加工成型。防爆膜中间为铝箔,铝箔被热塑性塑料包裹。通过加压、加热的方式,将防爆膜固定在泄压孔外表面。热塑性塑料与盖板粘接在一起,并且部分热塑性塑料填充进入泄压孔,起到提高粘接强度的作用。防爆原理为：当动力电池内部发生热失效,产生高温、高压内部环境,高温使热塑性塑料软化或熔化,进而降低防爆膜与盖板的粘接强度,高压使防爆膜被冲开,实现动力电池内部泄压和防爆功能。有益效果是：防爆结构原材料易于获取且可国产化、加工工艺简单、机构巧妙,可以显著降低动力电池制造成本。(The invention discloses a power battery explosion-proof structure and a power battery thereof. The explosion-proof structure comprises a pressure relief hole and an explosion-proof membrane. The pressure relief hole is directly formed on the cover plate in a machining mode. The middle of the explosion-proof film is an aluminum foil which is wrapped by thermoplastic plastics. The explosion-proof membrane is fixed on the outer surface of the pressure relief hole in a pressurizing and heating mode. The thermoplastic plastic is bonded with the cover plate, and part of the thermoplastic plastic is filled into the pressure relief holes, so that the bonding strength is improved. The explosion-proof principle is as follows: when the internal of the power battery is thermally disabled, a high-temperature and high-pressure internal environment is generated, the thermoplastic plastic is softened or melted at high temperature, the bonding strength between the explosion-proof film and the cover plate is further reduced, the explosion-proof film is broken at high pressure, and the internal pressure relief and explosion-proof functions of the power battery are realized. The beneficial effects are that: the explosion-proof structure has the advantages of easily obtained raw materials, localization, simple processing technology and ingenious mechanism, and can obviously reduce the manufacturing cost of the power battery.)

1. The utility model provides a power battery explosion-proof construction, comprises pressure release hole and rupture membrane, its characterized in that: the rupture disk is connected with a plurality of pressure relief holes, and part of the rupture disk material is filled into the pressure relief holes.

2. The power battery explosion-proof structure of claim 1, wherein: the middle of the explosion-proof film is an aluminum foil which is wrapped by thermoplastic plastics; or the upper layer of the explosion-proof membrane is aluminum foil, and the lower layer of the explosion-proof membrane is thermoplastic plastic.

3. The power battery explosion-proof structure according to claim 2, characterized in that: the overall dimension of the aluminum foil is larger than that of the pressure relief hole area, and the outer edge of the aluminum foil exceeds the outer edge of the pressure relief hole by more than 0.5mm, preferably 3-10 mm.

4. The power battery explosion-proof structure of claim 3, wherein: the pressure relief holes are multiple and are in a circular shape, an oval shape, a square shape or a combination thereof.

5. A power battery comprises a top cover, an electric core assembly, electrolyte and a shell, and is characterized in that: comprising an explosion-proof construction according to claims 1-4.

6. The power cell of claim 5, wherein: the explosion-proof structure is arranged on the top cover or the shell.

Technical Field

The invention relates to the field of electrochemical energy storage devices, in particular to an explosion-proof structure of a power battery and the power battery.

Background

Under the consensus of low-carbon economy and carbon neutralization, strategic planning supporting the development of new energy automobiles and wind-solar power generation and energy storage systems is provided in main countries around the world, the power battery industry is developed at a high speed, and the safety of the power battery is also generally regarded.

The power battery material is sensitive to moisture and oxygen and is usually designed into a sealing structure. The power battery has high energy density and flammable electrolyte, and in order to improve the safety performance of the power battery, a turnover piece open circuit structure or an explosion-proof valve pressure relief structure is usually designed.

The trip plate breaking structure or the explosion-proof valve pressure relief structure is usually an aluminum foil structural member. However, such aluminum foil is required to have excellent formability, high elongation, high strength, and high corrosion resistance. The common imported model MFX2 is expensive and is a raw material of a neck clamp.

In addition, the pressure relief structure of the explosion-proof valve of the power battery is mainly formed by welding an aluminum foil and a cover plate together through laser. And the laser welding mode has higher equipment investment cost and operation cost.

Disclosure of Invention

In order to realize the localization of raw materials of the power battery and reduce the manufacturing cost, the invention discloses an explosion-proof structure of the power battery and the power battery thereof, and the technical scheme is as follows:

the utility model provides a power battery explosion-proof structure comprises pressure release hole and rupture membrane, and rupture membrane links together with a plurality of pressure release holes to rupture membrane part material is filled and is got into the pressure release hole.

The pressure relief holes are multiple and are in a circular shape, an oval shape, a square shape or a combination thereof.

The middle of the explosion-proof film is an aluminum foil which is wrapped by thermoplastic plastics. Alternatively, when the insulation requirement of the power battery application occasion is not high, the upper layer is aluminum foil, and the lower layer is thermoplastic plastic.

The aluminum foil is made of the same material as the cover plate, the overall size of the aluminum foil is larger than that of the pressure relief hole area, and the outer edge of the aluminum foil exceeds the outer edge of any pressure relief hole by more than 0.5mm, preferably 3-10 mm.

The thermoplastic plastic can be softened or melted into any shape at a certain temperature, and the shape is not changed after cooling; when the temperature of the power battery use environment is less than 60 ℃, PE is preferred, and when the temperature is more than 60 ℃, PP is preferred.

A power battery comprises a top cover, an electric core assembly, electrolyte and a shell, and is characterized in that: by applying the explosion-proof structure, the pressure relief channel space can be released according to the practical application of the power battery, and the explosion-proof structure can be arranged on the top cover or the shell.

The invention is characterized in that: the power battery explosion-proof structure comprises a pressure relief hole and an explosion-proof membrane. The pressure relief hole can be directly machined and formed on the cover plate. The middle of the explosion-proof film is an aluminum foil which is wrapped by thermoplastic plastics. The explosion-proof membrane is fixed on the outer surface of the pressure relief hole in a pressurizing and heating mode. The thermoplastic plastic is bonded with the cover plate of the pressure relief hole, and part of the thermoplastic plastic is filled into the pressure relief hole, so that the bonding strength is improved. The aluminum foil material is consistent with the cover plate material, such as 3003 or 1060 which are commonly used.

When the internal of the power battery is thermally disabled and generates a high-temperature and high-pressure internal environment, the thermoplastic plastic is softened or melted at high temperature, so that the bonding strength between the explosion-proof film and the cover plate is reduced, the explosion-proof film is broken at high pressure, and the internal pressure relief and explosion prevention of the power battery are realized.

The invention has the beneficial effects that: the explosion-proof structure has the advantages of easily obtained raw materials, localization, simple processing technology and ingenious structure, and obviously reduces the manufacturing cost of the power battery.

Drawings

FIG. 1: an explosion-proof structure schematic diagram of a power battery.

FIG. 2: a schematic diagram of a pressure relief hole of an explosion-proof structure of a power battery.

FIG. 3: a schematic diagram of an explosion-proof membrane structure of an explosion-proof structure of a power battery.

FIG. 4: a schematic diagram of an embodiment of a pressure relief hole expansion of an explosion-proof structure of a power battery.

In the figure, a cover plate 1, a positive pole component 2, a negative pole component 3, a liquid injection hole 4, a pressure relief hole 5, a thermoplastic material 6, an aluminum foil 7, an explosion-proof membrane 20, a top cover 100 and an explosion-proof valve 567.

Detailed Description

The invention and its advantages are explained in detail below with reference to the accompanying drawings and detailed description.

Referring to fig. 1: a power battery explosion-proof structure schematic diagram, fig. 2: a schematic diagram of a pressure relief hole structure of an explosion-proof structure of a power battery is used as a structure processing and assembling process of a pressure relief hole 5 and the like on a cover plate 1 explained as a preferred scheme.

And a positive pole mounting hole (not marked in the figure), a negative pole mounting hole (not marked in the figure), a liquid injection hole 4 and a double-sided groove (not marked in the figure) of a cover plate pressure relief hole area are formed on the cover plate 1 through machining. And then a pressure relief hole 5 is machined in a pressure relief hole area (not marked in the figure) of the cover plate.

The small diameter of the vent 5 is designed to enhance the effect of securing the rupture disk 20, but there is a possibility that the thermoplastic material 6 will block the vent 5, causing an increase in venting pressure. The number of the pressure relief holes 5 is multiple, and in order to strengthen the effect of fixing the explosion-proof membrane 20, a circle of pressure relief holes 5 are needed to be designed around the inner ring of the aluminum foil 7. The diameter and the number of the pressure relief holes 5 can be comprehensively evaluated according to a pressure relief pressure target value and the service life of the power battery.

The positive pole assembly 2 and the negative pole assembly 3 are respectively installed in a positive pole mounting hole (not marked in the figure) and a negative pole mounting hole (not marked in the figure), and the installation mode is an industry general technology and is not described in detail herein.

In the cover plate pressure relief hole area (not marked in the figure), a double-sided groove (not marked in the figure) is machined. The explosion-proof film 20 is used for reducing the weight of the cover plate and improving the energy density of the power battery, and the explosion-proof film 20 is used for installing. The depth design of the pressure relief hole 5 can be comprehensively evaluated according to the target value of the pressure relief pressure and the service life of the power battery.

Referring to fig. 1: a power battery explosion-proof structure schematic diagram, fig. 3: a schematic diagram of the explosion-proof membrane structure of the explosion-proof structure of the power battery is provided, which illustrates the process of processing the explosion-proof membrane 20 and assembling with the pressure relief hole 5 to form the explosion-proof valve 567.

Thermoplastic 6, preferably PE when the power cell application ambient temperature is <60 ℃; PP is preferred when the power cell application environment temperature is >60 degrees in a high temperature environment. The thickness of the thermoplastic plastic 6 can be comprehensively evaluated according to the target value of the pressure relief pressure and the service life of the power battery. The outer edge of the thermoplastic plastic 6 exceeds the outer edge of the aluminum foil 7 by more than 0.5mm, preferably 3-10 mm.

The main function of the aluminium foil 7 is to prevent moisture from entering the interior of the power cell. The external dimension of the aluminum foil 7 is larger than the whole dimension of the pressure relief hole area (not marked in the figure), and the outer edge of the aluminum foil 7 exceeds the outer edge of any pressure relief hole 5 by more than 0.5mm, preferably 3-10 mm. The thickness of the aluminum foil 7 is preferably 0.01 to 0.50 mm. In order to prevent chemical corrosion between metals, the material of the aluminum foil 7 is consistent with that of the cover plate 1, such as the commonly used model 3003 or 1060.

In the first embodiment of the rupture disk 20, the three layers of thermoplastic 6, aluminum foil 7 and thermoplastic 6 are hot-pressed and combined to form the rupture disk. In the second embodiment of the rupture disk 20, the aluminum foil 7 is formed by coating with the thermoplastic plastic 6 by injection molding. In the third embodiment of the rupture membrane 20, when the insulation requirement of the power battery application occasion is not high, two layers of materials, namely the thermoplastic plastic 6 and the aluminum foil 7, are subjected to hot-pressing composite molding.

The explosion-proof membrane 20 is placed in a cover plate pressure relief hole area (not marked in the figure), the cylinder is used for driving a heating jig to heat the explosion-proof membrane 20 and the cover plate pressure relief hole area (not marked in the figure), the cylinder is used for applying pressure, the explosion-proof membrane 20 is connected with the pressure relief hole 5, and the thermoplastic material 6 of the explosion-proof membrane is filled into the pressure relief hole 5. By controlling the heating temperature and the air pressure of the air cylinder, the quantity of the thermoplastic material 6 filled into the pressure relief holes 5 in the part of the rupture membrane and the bonding strength between the rupture membrane 20 and the cover plate 1 and the pressure relief holes 5 are controlled. The pressure relief hole 5 and the rupture disk 20 are bonded together by a hot pressing method to form an explosion-proof valve 567.

Referring to fig. 4: in a schematic diagram of an embodiment of a pressure relief hole expansion of an explosion-proof structure of a power battery, an embodiment of the pressure relief hole 5 can be selected from a combination of a round type and a square type. The round pressure relief holes 5 around can strengthen the bonding force between the explosion-proof membrane 20 and the pressure relief holes 5 and improve the sealing performance of the explosion-proof membrane 20 on the power battery. The square pressure relief hole 5 can improve the processing and forming efficiency of the pressure relief hole 5 and reduce the manufacturing cost, but the sealing performance and the service life of the power battery are slightly inferior to the prior scheme shown in fig. 2.

A power battery comprises a top cover 1, a core assembly (not shown), an electrolyte (not shown) and a shell (not shown), and is characterized in that: the explosion-proof structure is applied. The pressure relief channel space can be realized according to the practical application of the power battery, and the explosion-proof structure can be arranged on the top cover or the shell. The power battery is generally assembled together in a series and/or parallel stacking mode in application, the pressure relief channel space is larger in the direction of the top cover, and the explosion-proof structure is preferably arranged on the top cover 1. The manufacturing process of the power battery is an alternative industry common technology, and detailed description is not expanded here.

Appropriate changes and modifications to the embodiments described above will become apparent to those skilled in the art from the disclosure and teachings of the foregoing description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

The foregoing is considered as illustrative of the preferred embodiments of the invention and is not to be construed as limiting the invention in any way. Those skilled in the art can make numerous possible variations and modifications to the present invention, or modify equivalent embodiments to equivalent variations, without departing from the scope of the invention, using the teachings disclosed above. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention should fall within the protection scope of the technical scheme of the present invention, unless the technical spirit of the present invention departs from the content of the technical scheme of the present invention.