CN216563327U

CN216563327U - Battery case packaging structure

Info

Publication number: CN216563327U
Application number: CN202122858241.8U
Authority: CN
Inventors: 王虞越
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-11-22
Filing date: 2021-11-22
Publication date: 2022-05-17
Anticipated expiration: 2031-11-22

Abstract

The utility model relates to a battery shell packaging structure which comprises a cylinder body with openings at two ends, a first end cover and a second end cover, wherein the first end cover and the second end cover are used for sealing the openings at two ends of the cylinder body, the cylinder body is made of an anticorrosive insulating soft material, the first end cover and the second end cover are respectively made of conductive metal and provided with a pole column, a positive plate and a negative plate of a battery cell are respectively welded with the first end cover or the second end cover, the peripheral surface of the end cover is provided with a coating layer made of the same material as the cylinder body, and the peripheral part of the end cover, which is combined with the cylinder body, is curled, compressed and sealed in a hot melting mode. Compared with the prior art, the utility model has the advantages of low shell cost, less packaging procedures, high packaging efficiency and the like.

Description

Battery case packaging structure

Technical Field

The utility model relates to the technical field of batteries, in particular to the field of packaging of shell structures of batteries such as lithium ion batteries and sodium ion batteries.

Background

The existing packaging structure and method for the shell structure of batteries such as lithium ion batteries, sodium ion batteries and the like mainly comprise three types:

firstly, a cylindrical steel shell 10 and an end cover 20 are packaged, as shown in fig. 6, a battery core is arranged in the steel shell 10 and serves as a negative electrode, an end cover serves as a positive electrode, an explosion-proof pressure relief device is generally arranged on the end cover structure, the end cover 20 is placed in a steel shell 10 rolling groove, and sealing is achieved by edge pressing.

Secondly, as shown in fig. 7, the square aluminum case 30 and the cover plate 40 are packaged together, the cover plate 40 is generally provided with an explosion-proof pressure relief device, the positive pole and the negative pole are arranged on the cover plate, and the joint of the aluminum case 30 and the cover plate 40 is sealed by laser welding.

And thirdly, in the aluminum-plastic composite film packaging structure, as shown in fig. 8, a pit is punched in advance on an aluminum-plastic composite film 50, a pit is punched on the aluminum-plastic composite film, a battery cell is placed in the pit, the aluminum-plastic composite film is subjected to edge sealing and sealing by hot pressing, and pressure relief is generally performed by self deformation of the aluminum-plastic composite film.

The existing packaging structure has the following disadvantages. Firstly, for the structure adopting the metal shell, the production cost is high, most metal shells adopt a multistep stretching and shell punching process, the metal materials are more, the die is complex, the shells need to be pasted with films in advance for protection when aluminum shell batteries are produced, and the shells need to be cleaned for oil removal and nickel plating for rust prevention when cylindrical steel shell batteries are produced. In addition, an end cover (plate) packaged by a cylindrical steel shell and a square aluminum shell is generally provided with an explosion-proof pressure relief device, and the manufacturing process is complicated. The square aluminum shell needs to adopt a laser welding mode, the sealing is realized by overlapping welding spots and welding spots, and the equipment such as a laser welding machine and the like is expensive. Secondly, for the structure that adopts the plastic-aluminum complex film casing, need dash hole in advance, top side seal, cut gasbag and secondary seal, efficiency is slow, seals the process complicacy, and the equipment prices such as dashing hole machine that uses are expensive.

SUMMERY OF THE UTILITY MODEL

The present invention is directed to provide a battery case package structure with high reliability, fast package speed, simple structure and low material cost, which overcomes the above-mentioned drawbacks of the prior art.

The technical scheme adopted by the utility model for solving the technical problems is as follows:

the utility model provides a battery case packaging structure, includes both ends open-ended barrel and is used for sealing this barrel both ends open-ended first end cover and second end cover, the barrel is anticorrosive insulating soft materials, first end cover and second end cover are made by conductive metal respectively and are equipped with utmost point post, and battery cell's positive plate and negative plate weld with first end cover or second end cover respectively, and the peripheral surface of end cover has the coating of the same material with the barrel, and this end cover periphery compresses tightly and hot melt is sealed with barrel joint part turn-up.

Further:

the first end cap and the second end cap are folded inwards along the edges.

The barrel is an aluminum-plastic composite film, the aluminum-plastic composite film comprises three layers, the middle layer is an aluminum foil, the inner layer is formed by compounding one or more than one of PET or PP, PE and PVDF engineering plastic materials, and the outer layer is formed by compounding one or more than one of PET or PP, PE, PVDF and PA engineering plastic materials.

The cylinder body is formed by compounding one or more than one of PET, PP, PE, PVDF and PA engineering plastic materials.

The first end cover is made of aluminum metal and serves as a battery positive end, and the second end cover is made of aluminum metal, copper nickel plating or iron nickel plating and serves as a battery negative end.

The inner surface of the periphery of the end cover is provided with a coating made of the same material as the cylinder body, and the inner surface of the periphery of the end cover is curled to wrap the joint part of the cylinder body for pressing and hot melting sealing.

And a temperature sensor is fixed at the center of any one of the first end cover and the second end cover, extends into the middle position inside the battery, is insulated from the battery core, and keeps a distance from the other end cover.

And the end cover fixed with the temperature sensor is also provided with a pressure sensor.

The pressure sensor and the temperature sensor are integrated.

The pressure sensor and the temperature sensor are arranged separately, and the pressure sensor can be arranged on the inner side surface of the end cover.

Compared with the prior art, the utility model has the following beneficial effects:

the cost of the shell is low, and can be reduced by 50% or more compared with the existing metal shell;

the packaging process is less, compared with the battery packaged by the aluminum-plastic composite film, the battery packaged by the aluminum-plastic composite film needs to be punched with pits in advance, and the processes of reserving an air bag, punching the air bag later, sealing for the second time and the like are needed in the manufacturing process;

the efficiency is high, and compared with a battery packaged by an aluminum metal shell, the aluminum shell battery needs laser welding of the metal shell; the equipment that the encapsulation was used is few and cheap, and jar body main part only need cut length as required, and the sealed spinning sealing equipment that only needs the same type of upper and lower lid.

Drawings

FIG. 1 is a schematic view of a battery housing packaging structure according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a cylindrical body of an embodiment of a battery housing package according to the present invention;

FIG. 3 is a schematic view showing a rectangular parallelepiped barrel according to an embodiment of the battery case packaging structure of the present invention;

fig. 4 is a schematic diagram of a battery cell after being loaded into a barrel in a packaging process according to an embodiment of the battery case packaging structure of the present invention;

FIG. 5 is a schematic diagram of a battery case packaging structure according to an embodiment of the present invention, in which an end cap is covered on a can and is bonded to the can by crimping and hot-melt sealed;

FIG. 6 is a schematic diagram of another embodiment of a battery housing package structure according to the present invention;

fig. 7 is a schematic view of a first prior art battery housing packaging arrangement;

fig. 8 is a schematic view of a second prior art battery housing packaging arrangement;

fig. 9 is a schematic view of a third prior art battery housing packaging arrangement.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

A battery case packaging structure, for example lithium ion and sodium ion battery's shell packaging structure, as shown in fig. 5, includes both ends open-ended barrel 1 and is used for sealing this barrel both ends open-ended first end cover 2 and second end cover 3, barrel 1 is anticorrosive insulating soft materials, first end cover 2 and second end cover 3 are made by conductive metal respectively and are equipped with utmost point post, and battery electricity core 4's positive plate and negative pole piece weld with first end cover or second end cover respectively, the peripheral surface of end cover has the coating of the same material with the barrel, and this end cover periphery and barrel combine some turn-ups to compress tightly and hot melt sealed.

In some embodiments, as shown in fig. 5, the inner surface of the end cover periphery has a coating made of the same material as the cylinder, the inner surface of the end cover periphery is crimped around the cylinder joint portion and pressed and hot-melted and sealed, and a hot-melting sealing layer 7 is arranged between the inner surface of the end cover periphery and the cylinder.

In some embodiments, as shown in FIG. 1, the first end cap edge 21 and the second end cap edge 31 are folded inwardly to achieve a reduced outer edge.

In some embodiments, the barrel is an aluminum-plastic composite film, the aluminum-plastic composite film comprises three layers, the middle layer is an aluminum foil, the inner layer can be formed by compounding PET, or one or more of PP, PE and PVDF engineering plastic materials, and the outer layer can be formed by compounding PET, or one or more of PP, PE, PVDF and PA engineering plastic materials. The intermediate layer aluminum foil plays a role in supporting, sealing and rapid heat dissipation, the inner layer plays a role in insulation and corrosion prevention, and the outer layer plays a role in insulation and scratch prevention.

In some embodiments, the cylinder comprises only one layer and is compounded by one or more than one of PET, PP, PE, PVDF and PA engineering plastic materials.

For a lithium ion battery, the first end cap is made of aluminum metal as the battery positive end and the second end cap is made of copper, copper nickel or iron nickel as the battery negative end.

For a sodium ion battery, the first end cap is made of aluminum metal as the battery positive terminal and the second end cap is also made of aluminum metal as the battery negative terminal.

The central parts of the surfaces of the first end cover and the second end cover are provided with welding surfaces for welding the pole columns, and the pole columns are internally provided with threads which can be externally connected to realize power output. One of the first end cover and the second end cover is reserved with a liquid injection hole as a liquid injection channel, and the liquid injection channel is plugged by a ball or a cylinder which is made of the same material as the end cover after liquid injection. The first end cover and the second end cover are respectively connected with a positive plate aluminum foil and a negative plate copper foil (the negative plate of the sodium ion battery can be an aluminum foil) of the battery cell through laser spot welding or ultrasonic welding, and the periphery of the end cover is combined with the barrel body, and sealing and insulation can be realized through edge curling hot melting or hot melting after edge curling. The outer edge part is shaped, so that the purposes of reducing the outer edge, namely no edge angle and reducing the total height of the battery are achieved.

The packaging method of the battery case packaging structure, as shown in fig. 1 to 5, includes the following steps:

➀ the raw material of the cylinder with two open ends is made of antiseptic insulating soft material, and the size of the cross section of the raw material of the cylinder is the same as that of the battery to be packaged.

➁ cutting the raw material of the cylinder according to the height of the battery to be packaged to obtain a cylinder with two open ends, wherein the shape of the cylinder can be a cylinder as shown in figure 2 or a cuboid as shown in figure 3; the barrel is made of an aluminum-plastic composite film, the aluminum-plastic composite film comprises three layers, the middle layer is an aluminum foil, the inner layer is formed by compounding one or more of PET or PP, PE and PVDF engineering plastic materials, and the outer layer is formed by compounding one or more of PET or PP, PE, PVDF and PA engineering plastic materials. The cylinder body can also be compounded by one or more than one of PET or PP, PE, PVDF and PA engineering plastic materials.

➂ the battery cell is loaded into the cylinder with one end having a positive electrode plate 41 such as aluminum foil and the other end having a negative electrode plate 42 such as copper foil, and the sodium ion battery can also be aluminum foil, as shown in fig. 4.

➃ the first end cap 2 is covered on the upper end of the cylinder 1, the first end cap 2 is welded with the positive plate of the battery cell 4 by laser spot welding or ultrasonic welding, the peripheral surface of the first end cap 2 is coated with a coating made of the same material as the cylinder, and the periphery of the end cap and the combination part of the cylinder are curled, compressed and sealed by hot melting. The first end cover is hermetically connected with the cylinder body; covering a second end cover 3 at the lower end of the cylinder body 1, welding the second end cover 3 and a negative plate of the battery core 4 in a laser spot welding or ultrasonic welding mode, coating the peripheral surface of the end cover on the periphery of the second end cover 3, which is made of the same material as the cylinder body, and crimping, pressing, hot melting and sealing the joint part of the periphery of the end cover and the cylinder body; the first end cap and the second end cap are respectively made of conductive metal and provided with a pole 5, as shown in fig. 5;

➄ setting a liquid injection hole 6 on the first or second end cap, injecting electrolyte into the barrel from the liquid injection hole, closing the liquid injection hole, and shaping by pressing edge as shown in FIG. 1.

In some embodiments, the inner surface of the periphery of the end cover is provided with a coating made of the same material as the cylinder body, the inner surface of the periphery of the end cover is crimped and wrapped on the joint part of the cylinder body to be pressed and sealed in a hot melting mode, and a hot melting sealing layer 7 is arranged between the inner surface of the periphery of the end cover and the cylinder body.

In some embodiments, as shown in fig. 1, the edge-pressing reshaping in step ➄ is to fold the first end cap edge 21 and the second end cap edge 31 inward to achieve corner-free outer edges and reduced cell height.

Due to the adoption of the technical scheme, the utility model has the following technical effects:

in the existing lithium ion and sodium ion batteries, moisture is a natural enemy, the packaging material and the packaging mode need to prevent moisture permeation and invasion for a long time, and the manufacturing process needs to pay special attention to moisture removal and how to prevent water, and the using process needs to prevent water, so the battery manufacturing industry always strives to improve the packaging effect of the batteries to achieve the best waterproof effect. The shell wall of the existing cylindrical steel shell packaged battery is made of economical and cheap metal, and can effectively prevent moisture from invading, but the rolling groove and edge pressing seal of the positive and negative electrode combination part is mechanical seal. The shell wall of the existing square aluminum shell packaged battery is made of economical and cheap metal, although the existing square aluminum shell packaged battery can effectively prevent water from invading, the joint of the positive and negative metal poles and the cover plate is made of organic insulating material, and different materials are sealed and not welded. By adopting the packaging structure and the packaging method, the sealing and combining part is made of the same anticorrosive and insulating soft material such as an organic insulating material, and the sealing effect is better in a welding mode.

The middle layer of the aluminum-plastic composite membrane of the existing aluminum-plastic composite membrane packaged battery is aluminum foil packaging and is heat seal sealing, although the middle layer of the aluminum-plastic composite membrane can effectively prevent water from invading, the internal pressure of the battery is increased along with the time lapse of the heat seal sealing seam after packaging, and the electrolyte is easy to leak from the heat seal sealing seam. The heat seal seam is made of organic materials, and external moisture can also enter the heat seal seam due to natural aging over time, and gas is generated by electrolysis or gas is generated by material deterioration, so that the battery swells and the service life is shortened. Under the interaction between the inside and the outside, the sealing failure of the aluminum-plastic composite film packaged battery is the main short plate compared with the batteries of other existing packaging modes. This is also one of the main reasons why the packaged battery of this technology fails in its life cycle. The sealing part of the insulating soft material such as the aluminum-plastic composite film is sealed by welding, the metal blank pressing at the outer edge of the cover plate deforms to generate pressure to seal the sealing part again and is kept continuously in the life cycle of the battery, and the edge metal pressure at the sealing part is kept to greatly improve the bonding force and reliability of the sealing part, so that the electrolyte leakage caused by the increase of the internal pressure of the battery is effectively prevented, the external moisture is prevented from entering the battery, the possibility of gas generation caused by the deterioration of the internal material of the battery is reduced, the battery failure is prevented, and the service life of the battery is prolonged.

In the existing lithium ion battery, if the internal failure of the battery or the short circuit of the battery caused by external force occurs, the internal pressure of the battery is rapidly increased and thermal failure occurs, and if the pressure reaches a certain critical point, the pressure cannot be relieved, and the battery explodes. Therefore, the existing batteries adopting the cylindrical and aluminum shell packaging modes are provided with safety explosion-proof valves, namely, before the internal pressure reaches a certain critical point, the explosion-proof valves are broken to release the pressure. The explosion-proof valve is generally arranged on the cover plate, and has a complex structure and high cost. The battery shell packaging structure and the method of the utility model have the advantages that the cylinder body is made of insulating soft materials such as the aluminum-plastic composite film, the internal pressure of the aluminum-plastic composite film is increased when the battery is out of control, so that the cylinder body deforms and expands until the battery is broken, the cylinder body plays the role of an explosion-proof valve, a special explosion-proof valve is not needed, the structure is simple, the cost is low, and the reliability is high.

The technical field is always striving to improve the gravimetric specific energy of the battery, and the selection of light materials with the same function is one of effective ways. The battery with the metal shell such as the prior cylinder, the aluminum shell and the like has the advantages that the can body is made of metal, the wall is thicker, the using amount is more, and the weight is heavy, and by adopting the battery shell packaging structure and the method, the weight of the can body is reduced to 20 percent or less of the original weight, the using amount of the metal is greatly reduced, and the gravimetric specific energy of the battery is improved.

In the conventional battery with a metal shell such as a cylinder, an aluminum shell and the like, once the height of the battery is changed, the cost and the efficiency of a special mold are increased when the shell is stretched, and by adopting the packaging structure and the method of the battery shell, the length of a cylinder can be freely cut without a special mold and without leftover materials.

The traditional aluminum-shell battery needs laser welding sealing, the equipment is expensive, and the welding efficiency is low.

In some embodiments, as shown in fig. 6, a temperature sensor 8 is fixed at the center of one end cap 2 of the battery casing packaging structure, and the temperature sensor 8 is connected with the battery management system in a communication manner, and the temperature sensor 8 extends into the middle position inside the battery, and is insulated from the battery cell 14 and is kept at a distance from the other end cap 3. The end cover fixed with the temperature sensor can be also provided with a pressure sensor. The pressure sensor may be integral with the temperature sensor or may be separate from the temperature sensor. When separately disposed, the pressure sensor may be disposed on an inner side of the end cap.

During specific packaging, after the battery cell 14 of the battery is wound, the cylinder body 1 is placed, the needle type integrated temperature and pressure sensor is placed in the center of the center hole of the battery cell, the bottom of the sensor is not in contact with the bottom of the battery, the diameter of the sensor is smaller than that of the center hole of the battery cell, and the sensor is insulated from the positive plate and the negative plate of the battery cell. Then the end cover and the cylinder are packaged together to realize sealing. In this embodiment, the pin 81 is disposed in the middle of one of the poles 5. In another embodiment, when the barrel is a cuboid, the two poles are arranged on the same end cover, and the plug pin is arranged between the two poles.

After the packaging is finished, the part of the temperature sensor 8 exposed out of the outer surface of the end cover is a pin 81, and the pin 81 is connected to a BMS or other data processing terminals through a lead wire, so that data uploading and real-time monitoring are realized.

Through embedding temperature sensor and pressure sensor etc. in monomer intelligent battery device electricity core, these sensors are equivalent to battery system's nerve ending, and the small change of battery performance can be detected by the sensor in real time, can in time calculate according to these detected information BMS and judge whether the battery is inside unusual to in time initiative early warning, stop work, arouse extinguishing device or "self-destruction" battery system when appearing unusually, can improve battery system security by a wide margin. And through calculating the detection data, the battery with potential hidden danger can be found in advance, and the target battery can be simply and accurately found during maintenance, so that the maintenance accuracy of the battery system is improved, the maintenance cost is greatly reduced, and the life cycle of the battery system is prolonged.

It should be understood that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same, and those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some technical features; and such modifications and substitutions are intended to be included within the scope of the appended claims.

Claims

1. A battery case packaging structure is characterized in that: the battery cell comprises a cylinder body with two open ends, and a first end cover and a second end cover which are used for sealing the two open ends of the cylinder body, wherein the cylinder body is made of an anticorrosive insulating soft material, the first end cover and the second end cover are respectively made of conductive metal and provided with a pole column, a positive plate and a negative plate of the battery cell are respectively welded with the first end cover or the second end cover, the peripheral surface of the end cover is provided with a coating made of the same material as the cylinder body, and the periphery of the end cover is pressed with the curling of a cylinder body combining part and is sealed by hot melting.

2. The battery case packaging structure according to claim 1, wherein: the first end cap and the second end cap are folded inwards along the edges.

3. The battery case packaging structure according to claim 1, wherein: the barrel is an aluminum-plastic composite film, the aluminum-plastic composite film comprises three layers, the middle layer is an aluminum foil, the inner layer is one of PET or PP, PE and PVDF engineering plastic materials, and the outer layer is one of PET or PP, PE, PVDF and PA engineering plastic materials.

4. The battery case packaging structure according to claim 1, wherein: the cylinder body is made of one of PET or PP, PE, PVDF and PA engineering plastics.

5. The battery case packaging structure according to claim 1, wherein: the first end cover is made of aluminum metal and serves as a battery positive end, and the second end cover is made of aluminum metal, copper nickel plating or iron nickel plating and serves as a battery negative end.

6. The battery case packaging structure according to claim 1, wherein: the inner surface of the periphery of the end cover is provided with a coating made of the same material as the cylinder body, and the inner surface of the periphery of the end cover is curled to wrap the joint part of the cylinder body for pressing and hot melting sealing.

7. The battery case encapsulating structure according to any one of claims 1 to 6, wherein: and a temperature sensor is fixed at the center of any one of the first end cover and the second end cover, extends into the middle position inside the battery, is insulated from the battery core, and keeps a distance from the other end cover.

8. The battery case packaging structure according to claim 7, wherein: and the end cover fixed with the temperature sensor is also provided with a pressure sensor.

9. The battery case enclosing structure according to claim 8, wherein: the pressure sensor and the temperature sensor are integrated.

10. The battery case enclosing structure according to claim 8, wherein: the pressure sensor and the temperature sensor are arranged separately, and the pressure sensor can be arranged on the inner side surface of the end cover.