TWI529996B - Soft package lithium battery package structure - Google Patents

Description

Soft pack lithium battery package structure

The invention relates to a lithium battery package structure, in particular to a package structure of a soft lithium battery.

Since most high-power electronic products such as automobiles, mobile phones, and notebook computers have used nickel-cadmium batteries or lead-acid batteries in the past, lead and cadmium metals generated by such batteries are likely to cause environmental pollution, so most of them are now Lithium-ion batteries are substituted. Lithium batteries can be divided into primary batteries using lithium metal or lithium alloy as negative electrode materials, non-aqueous electrolyte solutions, and rechargeable batteries that rely on lithium ions to move between the positive and negative electrodes to generate electricity, and we generally use them in the 3C industry. Its automotive industry is a lithium-ion battery, referred to as a lithium battery.

Please refer to FIG. 1 and FIG. 2 , which are schematic diagrams and cross-sectional views of a conventional soft pack lithium battery package structure. According to the conventional lithium battery, there is mainly a soft case 10, and the current product of the soft case 10 is formed by the corresponding joining of two aluminum plastic films 11, 12, and the inner side of the commonly used aluminum plastic film 11, 12 The adhesive layer has an adhesive layer, and the adhesive layer has a viscosity after being melted by heat, so that the two aluminum plastic films 11 and 12 can be pressed together by a thermal compression bonding process.

The soft case 10 is covered with an electrode sheet group 20 and pole tips 21 and 22 for conducting positive electrodes and negative electrodes, and the pole tips 21 and 22 are partially exposed outside the soft case 10. In practice, the electrode assembly 20 is composed of a plurality of positive electrode sheets and a plurality of negative electrode sheets. After being composed, the pole tips 21 and 22 are electrically connected to the positive/negative electrodes of the electrode sheet group 20, respectively, and finally, the circumferences of the two aluminum plastic films 11 and 12 are directly pressed by thermocompression in a thermocompression manner. Package. The upper and lower surfaces of the pole shanks 21 and 22 for conducting the positive and negative electrodes may be provided with a sealing portion 13 which is bonded to the surfaces of the pole shanks 21 and 22 so that the aluminum plastic films 11 and 12 are in the pole shank 21 22, the pressure is up to the airtight function, or the aluminum plastic film 11, 12 is directly pressed by heat, so that the two aluminum plastic film 11 is adhered to the sealing portions of the upper and lower surfaces of the pole shanks 21, 22, respectively. 13.

However, during the charging/discharging process of the lithium battery, the internal combustion of the soft shell will cause the soft shell 10 to expand due to overheating, and the gas will form an outward stress 30, wherein the aluminum plastic film 11, 12 and the pole The sealing portion 13 connected to the shank 21, 22, the stress 30 will continuously impact the sealing portion 13, because the direction in which the aluminum plastic film 11, 12 expands outward is the same as the direction of degumming, and the stress 30 will directly impact. The bonding effect of the aluminum plastic films 11 and 12 at the sealing portion 13 is also softened and flowed by the hot gas to reduce the viscosity, and the impact of the stress 30 causes the aluminum plastic film 11 to be coated on the poles 21 and 22. The portion 13 is easy to generate pores, so that the electrolyte in the soft shell 10 will flow out through the pores, causing damage to the battery, which greatly degrades the service life of the battery.

Therefore, in order to solve the problem that the conventional soft-pack lithium battery package structure has insufficient stress in the sealing portion of the exposed pole shank, the present invention provides two corresponding joint pieces at the press-fit of each pole shank, and the pole shank is added. The bonding effect at the nip is used to correspond to the stress of the gas generated inside the soft-packed lithium battery during the charging/discharging process due to overheating.

In order to achieve the above object, the present invention discloses a soft lithium battery encapsulation junction. The structure is applied to a two-piece coating film to form a soft shell package for wrapping a lithium battery, and a two-pole handle electrically connected to the electrode tab group, and the two-pole handle portion is exposed. The soft case is characterized in that the periphery of the cover film is press-fitted at the pressing position of each pole shank to provide two correspondingly joined joint pieces, wherein the joint piece can be made of the same material as the cover film. Cut into pieces. Each of the engaging pieces has a first pressing area and a second pressing area, and the engaging faces of the first pressing areas of the two engaging pieces are correspondingly engaged and the poles are clamped in the middle, and the first pressures are The middle portion of the joint portion is respectively engaged on the two surfaces of the pole shank; and the second nip portion is located above the first nip portion, and the second nip portions are respectively folded away from the pole shank to the first The pressing area is respectively fixed, and the second pressing areas are respectively press-fitted and fixed with two pieces of aluminum plastic film.

Wherein, the first nip of each of the engaging pieces is identical to the second nip, and the width of the second nip of each of the engaging pieces is the same as the width of the surrounding of the covering film.

Wherein the middle portion of the first nip of each of the engaging pieces is extended downwardly along the pole shank to have a third nip area, and the width of the third nip area is greater than the width of the pole shank so that the pole shank is located The third nip of the two surface engaging sheets is correspondingly engaged and the pole shank is clamped in the middle for increasing the joint fixing effect.

Wherein, the coating film is an aluminum-plastic composite film or a plastic composite film, and the inner side of the coating film has an adhesive layer, and the adhesive layer has a viscosity after being melted by heat, and the corresponding two coating film can be pressed through a thermal compression bonding process. Hehe.

The invention has the advantages that two pieces of correspondingly joined engaging pieces are provided at the nip of each pole shank at the periphery of the covering film, by the first pressure of each piece of the engaging pieces The concave fold of the joint zone and the second press-fit section corresponds to the hot gas in the soft shell, because the first press-fit area of the joint piece and the second press-fit area are integrally formed, so the concave fold will have a more conventional technique. The better physical structure increases the stress of the coating film at the pinch of the pole shank, thus resisting the upward stress of the hot gas generated when the battery is discharged, avoiding the problem of electrolyte outflow of the soft-packed lithium battery, and prolonging the service life of the battery.

10‧‧‧Soft shell

11, 12‧‧‧Aluminum plastic film

20‧‧‧electrode sheet

21, 22‧‧‧

13‧‧‧Fitting Department

30‧‧‧ stress

(this invention)

100‧‧‧Soft shell

101, 102‧‧‧ Press

110, 120‧‧‧ coating film

200‧‧‧electrode sheet

210, 220‧‧‧ pole

300‧‧‧Joint piece

310‧‧‧First nip

320‧‧‧Second nip

330‧‧‧ Third nip

400‧‧‧ stress

1 is a schematic view of a conventional lithium battery package structure.

2 is a cross-sectional view showing a conventional lithium battery package structure.

3 is an exploded perspective view of the lithium battery package structure of the present invention.

4 is an exploded perspective view of the lithium battery package structure of the present invention.

FIG. 5 is a schematic perspective view of a lithium battery package structure of the present invention.

6 is a schematic cross-sectional view showing a lithium battery package structure of the present invention.

The detailed description of the present invention and the technical description of the present invention are further illustrated by the embodiments, but it should be understood that these embodiments are for illustrative purposes only and are not to be construed as limiting.

Please refer to FIG. 3 and FIG. 4 , which are schematic diagrams showing the package structure of the soft lithium battery of the present invention. The invention discloses a soft-package lithium battery package structure, which is applied to the nips 101 and 102 around the two cover films 110 and 120 to form a soft shell 100, and the cover films 110 and 120 are aluminum-plastic. a composite film or a plastic composite film, wherein the inner sides of the coating films 110 and 120 have a bonding surface of an adhesive layer, and the adhesive layer has a viscosity after being melted by heat, so The joint faces that are in contact with each other around the sheet coating films 110, 120 may be fixed by thermocompression bonding.

The soft case 100 is used to wrap the electrode sheet set 200 of the lithium battery, and the two pole handles 210 and 220 electrically connected to the two poles of the electrode sheet set 200, and the two pole handles 210 and 220 are partially exposed to the soft shell. Package 100. In the present embodiment, the two pole shanks 210 and 220 are illustrated on the same side of the soft package 100.

The present invention is characterized in that the peripheral nips 101, 102 of the cover film 110, 120 are provided with two correspondingly engaging engaging sheets 300 at the pressing positions of each of the pole shanks 210, 220, wherein the preferred embodiment is The bonding sheet 300 is cut out from the same material as the coating films 110 and 120.

Each of the engaging pieces 300 has a first pressing area 310 and a second pressing area 320. The two surfaces of each of the pole pieces 210 and 220 are respectively clamped by the first pressing area 310 of the two engaging pieces 300. The first nip 310 of the bonding piece 300 is correspondingly engaged by the bonding surface having the bonding layer and the pole shank 210 (220) is clamped in the middle, and the middle sections of the first nips 310 are respectively engaged with the pole shank a second surface of the 210 (220); and a second nip 320 above the first nip 310, the second nip 320 is folded away from the pole shank 210 (220) to the first a pressing portion 310, that is, a shape in which the concave portion is formed downward between the first pressing portion 310 and the second pressing portion 320, and at this time, the second pressing portion 320 of the two bonding sheets 300 has a bonding surface of the bonding layer. In addition, the second nip area 320 can be pressed and fixed corresponding to the nips 101, 102 around the coating films 110, 120, respectively.

Wherein, a middle portion of the first nip 310 of each of the engaging pieces 300 extends downwardly along the pole shank 210 (220) to form a third nip 330 (shown in FIG. 4), and the third The width of the nip 330 is greater than the width of the pole shank 210 (220), so that the third nip 330 of the bonding piece 300 on the two surfaces of the pole shank 210 (220) is correspondingly engaged, and the pole shank 210 is 220) is clamped in the middle to increase the joint fixing effect.

In practice, the bonding glue may be added to the upper and lower surfaces of the pole shanks 210 and 220, and the bonding glue is disposed on the middle portion of the first nip 310 and the third nip region 330 of each of the bonding sheets 300, so that each The joints of the engaging pieces 300 on the pole shanks 210, 220 are airtight.

Wherein, the first nip 310 and the second nip 320 of each of the bonding sheets 300 are optimally the same, and the width of the second nip 320 of each of the bonding sheets 300 is optimally the same as the foregoing two The widths of the peripheral nips 101, 102 of the sheet covering films 110, 120 are the same.

Referring to FIG. 5 and FIG. 6 , the present invention performs thermal compression bonding according to a known pressing process, thereby completing the packaging of the soft package 100 and completing the package structure of the soft lithium battery. In this way, at the exposed portions of the peripheral poles 210 and 220 of the soft package 100, two sheets of correspondingly joined engaging sheets 300 are provided at the press-fit portions of the pole pieces 210 and 220 around the covering films 110 and 120.

When the lithium battery is charged/discharged due to overheating and internal gas is generated to expand the soft package 100, the gas in the soft package 100 will form an outward pressure 400, wherein the pole shank The nip of 210, 220 (FIG. 6 is illustrated by the pole shank 210), by the first nip 310 of the bonding piece 300 and the concave fold of the second nip 320, in the first nip 310 and The structural recess formed by the second nip 320 will have a better bonding effect than the conventional direct bonding, so that the bonding piece 300 and the pole The debonding direction of the joint of the shank 210, 220 and the covering film 110, 120 is opposite to the direction of the stress 400, and the bonding piece 300 passes through the first nip 310 and the second nip 320, respectively. 220 and the cover film 110, 120 combined, having a larger joint area than the prior art; thus, the cover film 110, 120 at the press-fit of each pole shank 210, 220, because of the mutual engagement of two The gusset 300 will provide the best structural reinforcement through the structure of the gussets 300. The soft hull 100 will more effectively block the outward expansion of the soft crust 100 as it expands at each pole shank 210, 220. It reduces the gas generated by the discharge of the battery and generates a gap by external force, which causes the electrolyte to flow out and prolongs the service life of the battery.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

100‧‧‧Soft shell

101, 102‧‧‧ Press

110, 120‧‧‧ coating film

200‧‧‧electrode sheet

210, 220‧‧‧ pole

300‧‧‧Joint piece

310‧‧‧First nip

320‧‧‧Second nip

Claims (7)

A soft package lithium battery package structure, which is applied to a two-piece cover film and is pressed around to form a soft shell package for encapsulating a lithium battery, and a two-pole handle electrically connected to the electrode tab group. And the two-pole shank portion is exposed to the soft shell, wherein the periphery of the covering film is press-fitted at the pressing position of each pole shank to provide two corresponding engaging pieces, each of which has a first a pressing area and a second pressing area, the engaging faces of the first nip of the two engaging pieces are correspondingly engaged and the pole shank is clamped in the middle, and the middle sections of the first nip of the two engaging pieces are respectively engaged a second surface of the pole shank; and a second nip area above the first nip area, wherein the second nip area of each of the engaging pieces is folded downward from the pole shank to the first nip area, respectively, and The second pressing regions are respectively press-fitted and fixed to the coating film. The soft pack lithium battery package structure according to claim 1, wherein the first nip area and the second nip area of each of the joint sheets are the same. The soft pack lithium battery package structure according to claim 1, wherein a width of the second nip of each of the bonding sheets is the same as a width of the periphery of the coating film. The soft pack lithium battery package structure of claim 1, wherein a middle portion of the first nip of each of the engaging pieces extends downward along the pole shank to provide a third nip, and the third pressure The width of the lands is greater than the width of the pole shank such that the third nip of the gussets on the surface of the pole shank is correspondingly engaged and the pole shank is clamped in the middle. The soft pack lithium battery package structure according to claim 1, wherein the coating film is an aluminum-plastic composite film. The soft pack lithium battery package structure according to claim 1, wherein the coating film is a plastic composite film. The soft pack lithium battery package structure according to claim 1, wherein the bonding sheet and the coating film are made of the same material.