CN109671983B

CN109671983B - Battery cell

Info

Publication number: CN109671983B
Application number: CN201710961662.9A
Authority: CN
Inventors: 唐威; 甘承宏; 陈光辉; 张柏清
Original assignee: Dongguan Nvt Technology Co Ltd
Current assignee: Dongguan Nvt Technology Co Ltd
Priority date: 2017-10-16
Filing date: 2017-10-16
Publication date: 2024-06-07
Anticipated expiration: 2037-10-16
Also published as: CN109671983A

Abstract

The invention provides a battery unit which comprises a battery and a circuit board assembly. The battery includes a pouch and an electrode assembly received in the pouch. The wrapping bag has main part and top banding, and electrode assembly holds in the main part, and top banding links to each other and sets up in the front of main part along fore-and-aft direction, and electrode assembly's electrode terminal wears out in the top banding. The circuit board assembly is connected to the electrode terminal of the electrode assembly and is arranged in an accommodating space surrounded by the upper surface of the top sealing edge and the front end surface of the main body. The battery unit further comprises first insulating glue, and the first insulating glue at least covers the front end face of the main body, the upper surface of the top sealing edge and the section of the top sealing edge. The circuit board assembly is arranged in the accommodating space, so that space is saved, and the energy density of the battery unit is improved. The first insulating adhesive covers the top edge sealing, so that the insulation of the top edge sealing can be realized, the packaging bag can be prevented from being damaged under the extrusion of the circuit board assembly, the short circuit of the battery is prevented, and the safety performance of the battery unit is improved.

Description

Battery cell

Technical Field

The invention relates to the field of batteries, in particular to a battery unit.

Background

In the existing flexible-package secondary battery, a metal layer section in an aluminum plastic film can be exposed at the edge of a packaging edge of the packaging bag (usually made of the aluminum plastic film), the metal layer section is exposed, the risk of short circuit of an electric element is caused, and the metal layer section is easily corroded when exposed in the air, so that the safety quality problem exists.

In the prior art, the insulating tape is generally used for pasting and wrapping the packaging edge section layer, but the insulating tape needs a specific structural design, occupies the space of the secondary battery, reduces the energy density, and meanwhile, the insulating tape needs more materials and has low production benefit. In addition, the secondary battery needs to be connected with the circuit board to form the battery cell, but the space occupied by the circuit board is large, further reducing the energy density of the battery cell.

Disclosure of Invention

In view of the problems in the background art, it is an object of the present invention to provide a battery cell that can improve the safety performance and energy density of the battery cell and simplify the manufacturing process.

In order to achieve the above object, the present invention provides a battery unit including a battery and a circuit board assembly. The battery includes a pouch and an electrode assembly received in the pouch. The wrapping bag has main part and top banding, and electrode assembly holds in the main part, and top banding links to each other and sets up in the front of main part along fore-and-aft direction, and electrode assembly's electrode terminal wears out in the top banding. The circuit board assembly is connected to the electrode terminal of the electrode assembly and is arranged in an accommodating space surrounded by the upper surface of the top sealing edge and the front end surface of the main body. The battery unit further comprises first insulating glue, and the first insulating glue at least covers the front end face of the main body, the upper surface of the top sealing edge and the section of the top sealing edge.

The beneficial effects of the invention are as follows:

In the battery unit, the circuit board assembly can be arranged in the accommodating space formed by the upper surface of the top sealing edge and the front end surface of the main body, so that the space is saved, and the energy density of the battery unit is improved. Because the first insulating glue covers the section of the top sealing edge, the insulation of the top sealing edge can be realized, and meanwhile, because the first insulating glue also covers the upper surface of the top sealing edge and the front end surface of the main body, when the battery unit is impacted, the first insulating glue can avoid the packaging bag from being damaged under the extrusion of the circuit board assembly, the short circuit of the battery is prevented, and the safety performance of the battery unit is improved. In addition, the first insulating adhesive can be arranged on the packaging bag in a spraying, brushing or dispensing mode, the process is simple, the occupied space is small, and the energy density of the battery unit is further improved.

Drawings

Fig. 1 is a top view of a battery cell according to the present invention.

Fig. 2 is a cross-sectional view taken along line A-A of fig. 1.

Fig. 3 is an enlarged view of a portion of the dashed box in fig. 2.

Fig. 4 is a schematic view of the battery of fig. 3.

Fig. 5 is an exploded view of a battery cell according to the present invention.

Fig. 6 is a schematic view of a battery cell according to the present invention.

Fig. 7 is a cross-sectional view of the battery of fig. 6.

Fig. 8 is an enlarged view of a portion of the dashed box in fig. 7.

Fig. 9 is a schematic view of a package bag of a battery cell according to the present invention.

Fig. 10 is a right side view of a battery cell according to the present invention before the coating.

Fig. 11 is a right side view of the battery cell according to the present invention after the coating.

Fig. 12 is a left side view of a battery cell according to the present invention before the coating.

Fig. 13 is a left side view of a battery of the battery cell according to the present invention after the coating.

Fig. 14 is a top view of a battery cell according to the present invention before gumming.

Fig. 15 is a top view of a battery cell according to the present invention after the coating.

Fig. 16 is a bottom view of a battery cell according to the present invention before gluing.

Fig. 17 is a bottom view of the battery unit according to the present invention after the coating.

Fig. 18 is a rear view of a battery cell according to the present invention before the coating.

Fig. 19 is a rear view of a battery of the battery cell according to the present invention after the coating.

Fig. 20 is a front view of a battery cell according to the present invention before the coating.

Fig. 21 is a front view of a battery cell according to the present invention after the coating.

Wherein reference numerals are as follows:

1 cell 1132 second flange

11 Packaging bag 12 electrode assembly

111 Main body 121 electrode terminal

1111 Front end face 2 circuit board assembly

1112 Side 3 first insulating glue

1113 Top surface 4 second insulating glue

1114 Rear end face 5 insulating tape

1115 Bottom surface F packaging film

112 Top edge banding F1 inner fusion layer

1121 Upper surface F2 outer insulation layer

1122 Section F3 metal layer

1123 Lower surface X front-rear direction

113 Side edge banding Y left-right direction

1131 First fold Z up and down

Detailed Description

The battery cell of the present invention will be described in detail with reference to the accompanying drawings.

Referring to fig. 1 to 21, a battery unit according to the present invention includes a battery 1 and a circuit board assembly 2. The battery 1 includes a package 11 and an electrode assembly 12 housed in the package 11. The package bag 11 has a main body 111 and a top seal 112, the electrode assembly 12 is accommodated in the main body 111, the top seal 112 is connected to the main body 111 and provided in front of the main body 111 in the front-rear direction X, and the electrode terminal 121 of the electrode assembly 12 is penetrated from the top seal 112. The circuit board assembly 2 is connected to the electrode terminal 121 of the electrode assembly 12, and is disposed in a receiving space defined by the upper surface 1121 of the top seal 112 and the front end surface 1111 of the main body 111. The battery cell further includes a first insulating adhesive 3, and the first insulating adhesive 3 covers at least the front end surface 1111 of the main body 111, the upper surface 1121 of the top sealing rim 112, and the cross section 1122 of the top sealing rim 112.

Electrode assembly 12 also includes a positive electrode tab, a negative electrode tab, and a separator separating the positive and negative electrode tabs. The positive electrode sheet, the negative electrode sheet, and the separator may be wound together to form the wound electrode assembly 12, or may be sequentially laminated to form the laminated electrode assembly 12. The electrode assembly 12 may have two electrode terminals 121 connected to the positive electrode tab and the negative electrode tab, respectively. The electrode terminals 121 protrude outside the package bag 11 to electrically connect the electrode assembly 12 with the circuit board assembly 2. The package 11 also accommodates an electrolyte.

The circuit board assembly 2 may include a printed circuit board, and the electrode terminals 121 are electrically connected with the printed circuit board.

The packaging bag 11 can be formed by sealing and connecting an upper packaging film F and a lower packaging film F. In one embodiment, referring to fig. 9, a depression may be punched in one packaging film F, then the electrode assembly 12 is placed in the depression, and finally the two packaging films F are sealed and connected at the periphery of the depression to form the package 11. The portion of the two-layer packaging film F surrounding the electrode assembly 12 is the main body 111 of the packaging bag 11, and the portion of the two-layer packaging film F sealed and connected to close the recess is the packaging edge (wherein the packaging edge located in front of the main body and penetrated by the electrode 121 is the top sealing edge 112). In alternative embodiments, both layers of packaging film F may be stamped with dimples.

The two layers of packaging films F can be formed by folding one packaging film in half, or can be two independent packaging films.

The packaging film F has an inner fusion layer F1, an outer insulating layer F2, and a metal layer F3 located between the inner fusion layer F1 and the outer insulating layer F2. The inner fusion layer F1 may be polypropylene, the outer insulating layer F2 may be nylon, and the metal layer F3 may be aluminum foil. The inner fusion layers F1 of the two packaging films are fused together through hot pressing, so that sealing connection is realized. The packaging film F is subjected to a process of punching and cutting during the process of forming the packaging bag 11, and therefore, the metal layer F3 is exposed at the edge (for example, the section 1122 of the top seal 112) of the package edge (for example, the top seal 112 and the side seal 113 described later) formed after the packaging film F is sealed and connected, and the metal layer F3 is easily connected to other elements and causes a short circuit, so that the edge of the package edge needs to be subjected to an insulating process.

Since the main body 111 of the package bag 11 is required to house the electrode assembly 12, the main body 111 protrudes in the up-down direction Z with respect to the top seal 112, thereby forming a front end surface 1111, a side surface 1112, and a top surface 1113.

In the battery cell according to the present invention, the circuit board assembly 2 may be disposed in the receiving space defined by the upper surface 1121 of the top seal 112 and the front end surface 1111 of the main body 111, thereby saving space and improving the energy density of the battery cell. Because the first insulating glue 3 covers the cross section 1122 of the top sealing edge 112, insulation of the top sealing edge 112 (that is, avoiding exposure of the metal layer F3) can be achieved, and meanwhile, because the first insulating glue 3 also covers the upper surface 1121 of the top sealing edge 112 and the front end surface 1111 of the main body 111, when the battery unit is impacted, the first insulating glue 3 can avoid the packaging bag 11 from being damaged under extrusion of the circuit board assembly 2, prevent the battery 1 from being shorted, and improve the safety performance of the battery unit. In addition, the first insulating glue 3 can be arranged on the packaging bag 11 in a spraying, brushing or dispensing mode, the process is simple, the occupied space is small, and the energy density of the battery unit is further improved.

The first insulating glue 3 may also cover the lower surface 1123 of the top sealing edge 112.

The portion of the electrode terminal 121 of the electrode assembly 12 protruding from the package bag 11 is folded back and fixed to the circuit board assembly 2. The electrode terminals 121 are folded back to save space and improve the energy density of the battery cell. When the battery 1 and the circuit board assembly 2 are assembled, the circuit board assembly 2 may be directly disposed in front of the battery 1 in the front-rear direction X and fixedly connected with the electrode terminal 121, and then the electrode terminal 121 is folded back to turn over the circuit board assembly 2 to an accommodating space surrounded by the upper surface 1121 of the top seal 112 and the front end surface 1111 of the main body 111.

The thickness of the first insulating paste 3 may be 0.03mm to 2mm, preferably 0.1mm to 0.3mm. Since the first insulating adhesive 3 needs to protect the package bag 11 (the upper surface 1121 of the top sealing edge 112 and the front end surface 1111 of the main body 111) from the impact force of the circuit board assembly 2, a large thickness is required to effectively insulate the circuit board assembly 2 from the package bag 11.

The packaging bag 11 further has two side sealing edges 113, which are connected to the main body 111 and are disposed on two sides of the main body 111 along the left-right direction Y, and each side sealing edge 113 is bent and fixed to a side surface 1112 of the main body 111; the battery unit further comprises two layers of second insulating glue 4 respectively disposed on two sides of the main body 111 along the left-right direction Y, and each second insulating glue 4 at least covers the corresponding side edge 113 and the exposed portion of the side surface 1112 of the main body 111. The two side seals 113 are two of the package edges formed by the two-layer packaging film F, and in order to increase the energy density of the battery 1, the side seals 113 are typically bent and fixed to the side 1112 of the main body 111.

Since the second insulating adhesive 4 covers the exposed portions of the side 1112 and the side edge 113 of the main body 111, the second insulating adhesive 4 can improve the fixing strength of the side edge 113 while realizing the insulation of the side edge 113, prevent the side edge 113 from being opened when the battery unit oscillates, and improve the safety performance of the battery unit.

In addition, the packaging bag 11 that is generally used is formed by folding a single packaging film F in half, and in this case, the rear end of the side seal 113 in the front-rear direction X is both the folded portion of the packaging film F and the side 1112 of the main body 111 needs to be folded, so that the folded junction is easily broken, which results in exposure of the metal layer F3 and even leakage. Since the second insulating adhesive 4 covers the rear end of the side seal 113 in the front-rear direction X, the purpose of insulation and sealing can be achieved, preventing the metal layer F3 from being exposed. Preferably, each second insulating glue 4 further extends onto the rear end face 1114 of the main body 111 to cover two ends of the rear end face 1114 of the main body 111 along the left-right direction Y, so that the insulating effect of the second insulating glue 4 can be further improved, and the bent junction is protected. Further, each second insulating glue 4 extends and is connected as a whole and completely covers the rear end face 1114 of the main body 111, so that the coverage of the second insulating glue 4 can be enlarged, the bonding strength and sealing effect of the second insulating glue 4 can be improved, and the insulating effect of the rear end face 1114 of the main body 111 can be enhanced.

Each second insulating paste 4 may also extend onto the top surface 1113 of the main body 111 to cover both ends of the top surface 1113 of the main body 111 in the left-right direction Y. Thus, the coverage area of the second insulating adhesive 4 can be enlarged, and the bonding strength and sealing effect of the second insulating adhesive 4 can be improved. Further, the two layers of the second insulating glue 4 extend and are integrally connected, and completely cover the top surface 1113 of the main body 111 and the bottom surface 1115 of the main body 111 (of course, only the top surface 1113 of the main body 111 or the bottom surface 1115 of the main body 111 may be covered). Thus, the package 11 is coated with an insulating paste on all exposed surfaces thereof, thereby improving insulation and sealability of the package 11.

The thickness of the second insulating paste 4 is 0.02mm to 0.5mm, preferably 0.05mm to 0.15mm. The second insulating glue 4 has the main function of realizing the insulation of the side sealing edge 113, and is less impacted by the outside, so that the second insulating glue can have smaller thickness relative to the first insulating glue 3, thereby saving space and improving the energy density of the battery unit.

The side seal 113 may take on different fold configurations. For example, in one embodiment, each side seal 113 is of a single layer construction. Of course, in another embodiment, referring to fig. 6-8, each side edge 113 is folded into a first fold 1131 and a second fold 1132, and the first fold 1131 with a free end sandwiches the second fold 1132 with the side 1112 of the main body 111. Since the portion of the side seal 113 where the metal layer F is exposed is located on the free end of the first flange 1131, and the first flange 1131 is clamped between the second flange 1132 and the side 1112 of the main body 111, the double-layer structure can further improve the insulation effect of the side seal 113.

A molding scheme of the battery cell is described in detail below.

1) Firstly, fixing the battery 1 (the secondary battery after finishing the preamble process such as edge folding), adjusting the position of the spray gun so that the spraying direction is perpendicular to (of course, other angles are also possible) the left side 1112 of the main body 111, and then spraying glue by the spray gun and moving along the front-rear direction X, thereby coating insulating glue on the side edge 113 of the packaging bag 11 and the exposed portion of the side 1112 of the main body 111 (as shown in fig. 13);

2) The position of the spray gun (the position of the battery 1 can also be adjusted) is adjusted so that the spraying direction of the spray gun is perpendicular to the top surface 1113 of the main body 111, and then the spray gun is moved forward along the left end of the top surface 1113 in the front-rear direction X and is coated with insulating glue; when the spray gun moves to the boundary of the section 1122 of the top sealing edge 112, the spray gun moves in the left-right direction Y and coats the upper surface 1121 of the top sealing edge 112 with insulating glue; when the spray gun moves to the right end of the top sealing edge 112, the spray gun moves backwards along the front-back direction X and is coated with insulating glue (as shown in fig. 15), wherein the spraying amount can be properly increased when the upper surface 1121 of the top sealing edge 112 is coated with insulating glue;

3) Adjusting the position of the spray gun so that the spraying direction is perpendicular to the right side 1112 of the main body 111, and then spraying glue and moving the spray gun in the front-rear direction X, thereby coating insulating glue on the side edge 113 of the packaging bag 11 and the exposed portion of the side 1111 of the main body 111 (as shown in fig. 11);

4) Adjusting the position of the spray gun so that the spraying direction of the spray gun is perpendicular to the lower surface 1123 of the top sealing edge 112, and simultaneously covering the boundary of the section 1122 by the spraying range of the spray gun, and then moving in the left-right direction Y and coating insulating glue (as shown in FIG. 17);

5) The position of the spray gun is adjusted so that the spray direction of the spray gun is perpendicular to the rear end face 1114 of the main body 111, and then the spray gun moves in the left-right direction Y and is coated with insulating glue at the rear ends of the two side seal edges 113 in the front-rear direction X and at the two ends of the rear end face 1114 in the left-right direction Y (as shown in fig. 19);

6) The position of the spray gun is adjusted so that the spray direction of the spray gun is perpendicular to the front end surface 1111 of the main body 111, the spray range of the spray gun covers the section 1122 of the top sealing edge 112, and then the spray gun moves in the left-right direction Y and coats insulating glue on the front end surface 1111 of the main body 111 and the section 1122 of the top sealing edge 112;

7) The coated insulating glue is solidified to form a first insulating glue 3 and a second insulating glue 4;

8) The electrode terminal 121 of the electrode assembly 12 is welded to the circuit board assembly 2, and then the electrode terminal 121 is bent to rewind the circuit board assembly 2 into the receiving space defined by the upper surface 1121 of the top seal 112 and the front end surface 1111 of the main body 111.

Alternatively, the glue spreading method may also be a brushing or dispensing method, and the glue spreading or dispensing sequence may be set according to the requirement, and is not limited to the above steps.

The first insulating glue 3 and the second insulating glue 4 of the battery unit have large coverage range, so that the required gluing process is simple and the insulating effect is good. Meanwhile, in the gluing process, the positioning is simple, and the influence of errors is small.

Claims

1. A battery cell comprising a battery and a circuit board assembly;

The battery includes a package bag and an electrode assembly accommodated in the package bag;

The packaging bag is provided with a main body and a top sealing edge, the electrode assembly is accommodated in the main body, the top sealing edge is connected with the main body and arranged in front of the main body along the front-back direction, and an electrode terminal of the electrode assembly penetrates out of the top sealing edge;

It is characterized in that the method comprises the steps of,

The circuit board assembly is connected with the electrode terminal of the electrode assembly and is arranged in an accommodating space surrounded by the upper surface of the top sealing edge and the front end surface of the main body;

The battery unit further comprises first insulating glue, wherein the first insulating glue covers the front end face of the main body, the upper surface of the top sealing edge and the section of the top sealing edge;

The packaging bag is also provided with two side sealing edges which are connected with the main body and arranged at two sides of the main body along the left-right direction, and each side sealing edge is bent and fixed on the side surface of the main body;

The packaging bag is formed by folding a piece of packaging film;

The battery unit further comprises two layers of second insulating glue which are respectively arranged at two sides of the main body along the left-right direction, each second insulating glue covers the corresponding side edge and the exposed part of the side surface of the main body, and the second insulating glue covers the rear end of the side edge along the front-back direction;

The two layers of second insulating glue extend and are connected into a whole and completely cover the bottom surface of the main body.

2. The battery cell of claim 1, wherein the first insulating glue also covers a lower surface of the top seal.

3. The battery cell according to claim 1, wherein the portion of the electrode terminal of the electrode assembly protruding from the pouch is folded back and fixed to the circuit board assembly.

4. The battery cell of claim 1, wherein the first insulating paste has a thickness of 0.03mm to 2mm.

5. The battery cell according to claim 1, wherein each of the second insulating pastes further extends onto the top surface of the main body to cover both ends of the top surface of the main body in the left-right direction.

6. The battery cell according to claim 1, wherein each of the second insulating pastes further extends onto the rear end face of the main body to cover both ends of the rear end face of the main body in the left-right direction.

7. The battery cell of claim 1, wherein the two layers of the second insulating glue extend and are integrally connected and also completely cover the top surface of the body.

8. The battery cell of any one of claims 1-7, wherein the second insulating paste has a thickness of 0.02mm-0.5mm.

9. The battery cell of claim 1, wherein the battery cell comprises a plurality of cells,

Each side edge is of a single-layer structure; or (b)

Each side edge sealing is bent into a first folding edge and a second folding edge, and the first folding edge with the free end clamps between the second folding edge and the side face of the main body.