Soft package battery

Abstract

The utility model provides a soft package battery which comprises a shell, a battery cell, a gas-guide tube, a positive tab and a negative tab, the interior of the shell is divided into a first air bag, a battery cell cavity and a second air bag which are arranged in sequence, the first air bag and the battery cell cavity are vacuumized and heat-sealed, and the second air bag and the battery cell cavity are vacuumized and heat-sealed; the battery cell is arranged in the battery cell cavity; the two groups of air guide pipes are positioned in the shell, one group of air guide pipes are connected between the first air bag and the battery cell cavity, and the other group of air guide pipes are connected between the battery cell cavity and the second air bag; and the positive tab and the negative tab are respectively connected with a positive plate and a negative plate of the battery cell. The two sides of the battery cell cavity are respectively provided with the first air bag and the second air bag, and the distances from the air in the battery cell cavity to the first air bag and the second air bag are the same, so that the problem that the migration path of the air in the battery cell is relatively long due to the air far away from the air bags does not exist, the problem that black spots appear on the edge of a pole piece is avoided, and the performance and the safety of the battery are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a soft-pack battery. Background Technique

[0002] Soft-pack batteries are widely used in mobile devices, electric vehicles, energy storage systems and other fields due to their advantages such as high energy density, good safety performance and light weight. Currently, the production of soft-pack batteries usually uses aluminum-plastic film as the outer shell. After the electrode sheets are stacked, they are placed in the outer shell, a certain amount of electrolyte is injected, and it is "activated" through the formation process. The current positive electrode lithium supplementation technology is widely used, and most of the lithium supplementation agents will decompose to produce gas. If the electrode sheets or the electrolyte absorb water during the production process, or when a lithium supplementation agent is added to the battery due to capacity requirements, the battery is prone to generate more gas during formation, causing the battery to bulge or even crack, and the electrolyte to overflow, thereby affecting the battery performance.

[0003] In view of the above problems, the current common solution is to set an air bag on one side of the battery cell to collect and temporarily store the gas generated during the formation stage, and evacuate the gas and cut off the air bag after the formation is completed. However, the above method has the following disadvantages:

[0004] (1) When the soft-pack battery is formed, the gas at the end far from the air bag has a long migration path in the battery cell and is difficult to be completely discharged to the air bag, resulting in poor contact between the electrode sheet on one side of the battery cell and the electrolyte, and then causing black spots on the edge of the negative electrode sheet, ultimately affecting the performance of the soft-pack battery;

[0005] (2) When the gas generated by the formation of the traditional soft-pack battery is discharged to the air bag, it is easy to carry away the electrolyte. During the vacuum pumping, second sealing and cutting processes, the excess electrolyte in the air bag will be pumped out, resulting in insufficient liquid retention of the soft-pack battery. Content of the Utility Model

[0006] In view of this, the utility model provides a soft-pack battery to solve the technical problem that the gas at the end far from the air bag has a long migration path in the battery cell and is difficult to be completely discharged to the air bag, resulting in poor contact between the electrode sheet on one side of the battery cell and the electrolyte, and affecting the battery performance as mentioned in the above background technique.

[0007] The technical solution of the utility model is realized as follows:

[0008] The utility model provides a soft-pack battery, including a housing, a battery cell, an air duct, a positive electrode tab and a negative electrode tab, wherein:

[0009] The interior of the housing is divided into a first air bag, a battery cell cavity and a second air bag which are arranged in sequence. A vacuum heat seal is provided between the first air bag and the battery cell cavity, and a vacuum heat seal is provided between the second air bag and the battery cell cavity;

[0010] The battery cell is arranged in the battery cell cavity;

[0011] The air ducts are located inside the housing and there are two sets of them. One set of air ducts is connected between the first airbag and the battery cell cavity, and the other set of air ducts is connected between the battery cell cavity and the second airbag;

[0012] The positive electrode tab and the negative electrode tab penetrate into the battery cell cavity from outside the housing and are respectively connected to the positive electrode plate and the negative electrode plate of the battery cell.

[0013] On the basis of the above technical solutions, preferably, the housing is prepared by punching, cutting and hot-pressing an aluminum-plastic film. The aluminum-plastic film includes a folding line, a bottom film area and a cover film area. The bottom film area and the cover film area are symmetrically arranged on both sides of the folding line. The bottom film area is provided with a first bulging area, a second bulging area and a third bulging area; the cover film area is provided with a fourth bulging area, a fifth bulging area and a sixth bulging area. After the aluminum-plastic film is folded along the folding line, the first bulging area and the fourth bulging area together form the first airbag, the second bulging area and the fifth bulging area together form the battery cell cavity, and the third bulging area and the sixth bulging area together form the second airbag.

[0014] On the basis of the above technical solutions, preferably, a number of mutually parallel installation grooves are provided on one side of the first bulging area, the third bulging area, the fourth bulging area and the sixth bulging area close to the battery cell cavity. The installation grooves of the first bulging area and the fourth bulging area form a first placement area after folding, and the installation grooves of the third bulging area and the sixth bulging area form a second placement area after folding. The air ducts are placed in both the first placement area and the second placement area.

[0015] On the basis of the above technical solutions, preferably, the air duct includes a straight pipe section and a bent pipe section. The straight pipe section is placed in the installation groove, and the bent pipe section is arranged at one end of the straight pipe section close to the battery cell cavity. The opening of the bent pipe section faces the bottom of the battery cell cavity.

[0016] On the basis of the above technical solutions, preferably, the sum of the diameters of the air ducts placed in all the first placement areas is greater than or equal to half of the longitudinal length of the first airbag, and the sum of the diameters of the air ducts placed in all the second placement areas is greater than or equal to half of the longitudinal length of the second airbag.

[0017] On the basis of the above technical solutions, preferably, after heat-sealing the aluminum-plastic film, a first side seal, a second side seal, a top seal, a first middle seal and a second middle seal are formed. The first side seal and the second side seal are respectively located on both sides of the housing, the top seal is located at the top of the housing, the first middle seal is located between the first bulging area and the second bulging area, and the second middle seal is located between the first bulging area and the second bulging area.

[0018] Based on the above technical solutions, preferably, the first side seal, the top seal, and the first middle seal enclose the first airbag.

[0019] Based on the above technical solutions, preferably, the top seal, the first middle seal, and the second middle seal enclose the battery cell cavity.

[0020] Based on the above technical solutions, preferably, the second side seal, the top seal, and the second middle seal enclose the second airbag.

[0021] Based on the above technical solutions, preferably, after the first airbag and the second airbag are punctured and the gas is extracted, the finished product of the soft-pack battery is obtained by heat-sealing along the first middle seal and the second middle seal and cutting off the first airbag and the second airbag.

[0022] The soft-pack battery of the present utility model has the following beneficial effects compared with the prior art:

[0023] (1) By dividing the inside of the housing into a first airbag, a battery cell cavity, and a second airbag arranged in sequence, the first airbag and the second airbag are respectively arranged on both sides of the battery cell cavity. The gas in the battery cell cavity can enter the first airbag and the second airbag on both sides through the air duct and then be completely evacuated by pumping, solving the problem in the prior art that the gas on the far airbag side has a long migration path in the battery cell during the high-voltage formation process, and the gas generated at the far airbag end cannot be discharged in time, resulting in black spots at the edge of the electrode sheet, thereby improving the performance and safety of the battery; and the design of the double airbags of the first airbag and the second airbag can not only effectively discharge the gas generated during formation, but also prevent the internal pressure of the battery from being too high, thereby improving the service life of the battery;

[0024] (2) By the air duct including a straight pipe section and a bent pipe section, the straight pipe section is placed in the installation groove, the bent pipe section is arranged at one end of the straight pipe section close to the battery cell cavity, and the opening of the bent pipe section faces the bottom of the battery cell cavity. The length of the air duct is longer, which can extend the flow path of the electrolyte, and the distance from the gas at the bottom of the battery cell cavity to the air duct is shorter, so as to reduce the discharge of the electrolyte while discharging as much gas as possible, thereby ensuring the liquid retention amount of the battery;

[0025] (3) By the sum of the diameters of the air ducts placed in all the first placement areas being greater than or equal to half of the longitudinal length of the first airbag, and the sum of the diameters of the air ducts placed in all the second placement areas being greater than or equal to half of the longitudinal length of the second airbag, the flow rate of gas flow is ensured, so that the gas can be quickly and completely discharged into the first airbag and the second airbag, improving the reliability and stability of the device. Description of the Drawings

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Figure 1 It is a cross-sectional view of the soft-pack battery of the present invention;

[0028] Figure 2 It is a schematic structural view of the housing of the present invention unfolded into an aluminum-plastic film;

[0029] Figure 3 It is a schematic structural view of the air duct of the present invention.

[0030] Explanation of reference numerals: 1 - housing, 2 - battery cell, 3 - air duct, 4 - positive electrode tab, 5 - negative electrode tab;

[0031] 100 - aluminum-plastic film, 110 - folding line, 120 - bottom film area, 121 - first bulging area, 122 - second bulging area, 123 - third bulging area, 130 - cover film area, 131 - fourth bulging area, 132 - fifth bulging area, 133 - sixth bulging area, 140 - installation groove;

[0032] 11 - first air bag, 12 - battery cell cavity, 13 - second air bag, 14 - first side seal, 15 - second side seal, 16 - top seal, 17 - first middle seal, 171 - first placement area, 18 - second middle seal, 181 - second placement area; 31 - straight pipe section, 32 - bent pipe section. Detailed implementation manners

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0034] Refer to Figures 1-3 As shown, this embodiment proposes a soft-pack battery, including a housing 1, a battery cell 2, an air duct 3, a positive electrode tab 4, and a negative electrode tab 5, wherein:

[0035] The interior of the housing 1 is partitioned into a first airbag 11, a battery cell cavity 12, and a second airbag 13 that are arranged in sequence. The first airbag 11 and the second airbag 13 are respectively disposed on both sides of the battery cell cavity 12. A vacuum is drawn and heat-sealed between the first airbag 11 and the battery cell cavity 12, and a vacuum is drawn and heat-sealed between the second airbag 13 and the battery cell cavity 12;

[0036] The battery cell 2 is disposed in the battery cell cavity 12;

[0037] The air ducts 3 are located inside the housing 1 and there are two groups. One group of the air ducts 3 is connected between the first airbag 11 and the battery cell cavity 12, and the other group of the air ducts 3 is connected between the battery cell cavity 12 and the second airbag 13;

[0038] The positive electrode tab 4 and the negative electrode tab 5 penetrate into the battery cell cavity 12 from outside the housing 1 and are respectively connected to the positive electrode plate and the negative electrode plate of the battery cell 2.

[0039] In the soft-pack battery proposed in this embodiment, since the interior of the housing 1 is partitioned into a first airbag 11, a battery cell cavity 12, and a second airbag 13 that are arranged in sequence, and the first airbag 11 and the second airbag 13 are respectively provided on both sides of the battery cell cavity 12, the gas in the battery cell cavity 12 can enter the first airbag 11 and the second airbag 13 on both sides through the air ducts 3 and then be completely evacuated by pumping. This solves the problem in the prior art that during the high-voltage formation process, the gas on the far airbag side has a long migration path inside the battery cell 2, and the gas generated at the far airbag end cannot be discharged in time, resulting in black spots at the edge of the electrode plate, thereby improving the performance and safety of the battery; moreover, the design of the double airbags of the first airbag 11 and the second airbag 13 can not only effectively discharge the gas generated during formation, but also prevent the internal pressure of the battery from being too high, thereby increasing the service life of the battery.

[0040] In some embodiments, the housing 1 is prepared by punching, cutting, and hot-pressing an aluminum-plastic film 100. The aluminum-plastic film 100 includes a folding line 110, a bottom film region 120, and a cover film region 130. The bottom film region 120 and the cover film region 130 are symmetrically arranged on both sides of the folding line 110. The bottom film region 120 is provided with a first bulging region 121, a second bulging region 122, and a third bulging region 123; the cover film region 130 is provided with a fourth bulging region 131, a fifth bulging region 132, and a sixth bulging region 133. After the aluminum-plastic film 100 is folded along the folding line 110, the first bulging region 121 and the fourth bulging region 131 together form the first airbag 11, the second bulging region 122 and the fifth bulging region 132 together form the battery cell cavity 12, and the third bulging region 123 and the sixth bulging region 133 together form the second airbag 13. Through the above process, a sealed housing 1 is obtained, and the interior of the housing 1 is partitioned into a first airbag 11, a battery cell cavity 12, and a second airbag 13 arranged in sequence. The first airbag 11 and the second airbag 13 are respectively arranged on both sides of the battery cell cavity 12. The distance from the gas in the battery cell cavity 12 to the first airbag 11 and the second airbag 13 is the same, and there is no problem of a long gas migration path in the battery cell 2 due to the gas far from the airbag, avoiding the problem of black spots at the edges of the electrode sheets caused by the gas generated at the end far from the airbag not being discharged in time.

[0041] In some embodiments, a plurality of mutually parallel mounting grooves 140 are provided on one side of the first bulging region 121, the third bulging region 123, the fourth bulging region 131, and the sixth bulging region 133 close to the battery cell cavity 12. The mounting grooves 140 of the first bulging region 121 and the fourth bulging region 131 form a first placement area 171 after folding, and the mounting grooves 140 of the third bulging region 123 and the sixth bulging region 133 form a second placement area 181 after folding. The air guide tubes 3 are placed in both the first placement area 171 and the second placement area 181. Through the air guide tubes 3 placed in both the first placement area 171 and the second placement area 181, the gas in the battery cell cavity 12 can enter the first airbag 11 and the second airbag 13 on both sides through the air guide tubes 3, and then the air is completely exhausted by pumping.

[0042] In some embodiments, the air duct 3 includes a straight pipe section 31 and a bent pipe section 32. The straight pipe section 31 is placed in the installation groove 140, and the bent pipe section 32 is arranged at one end of the straight pipe section 31 close to the battery cell cavity 12. The opening of the bent pipe section 32 faces the bottom of the battery cell cavity 12. By arranging the bent pipe section 32 at one end of the straight pipe section 31 close to the battery cell cavity 12 and the opening of the bent pipe section 32 facing the bottom of the battery cell cavity 12, the length of the air duct 3 is longer, which can extend the flow path of the electrolyte. The distance from the gas at the bottom of the battery cell cavity 12 to the air duct 3 is shorter, so as to reduce the discharge of the electrolyte while discharging as much gas as possible, thereby ensuring the liquid retention amount of the battery.

[0043] In some embodiments, the sum of the diameters of the air ducts 3 placed in all the first placement areas 171 is greater than or equal to half of the longitudinal length of the first air bag 11, and the sum of the diameters of the air ducts 3 placed in all the second placement areas 181 is greater than or equal to half of the longitudinal length of the second air bag 13. Through the above settings, the flow rate of gas flow can be ensured, so that the gas can be quickly and completely discharged into the first air bag 11 and the second air bag 13, improving the reliability and stability of the device.

[0044] In some embodiments, after the aluminum plastic film 100 is heat-sealed, a first side seal 14, a second side seal 15, a top seal 16, a first middle seal 17 and a second middle seal 18 are formed. The first side seal 14 and the second side seal 15 are respectively located on both sides of the housing 1, the top seal 16 is located at the top of the housing 1, the first middle seal 17 is located between the first bulging area 121 and the second bulging area 122, and the second middle seal 18 is located between the first bulging area 121 and the second bulging area 122. After heat-sealing, a sealed housing 1 is formed, which does not affect the formation operation.

[0045] In some embodiments, the first side seal 14, the top seal 16 and the first middle seal 17 enclose the first air bag 11. By enclosing the first air bag 11 with the first side seal 14, the top seal 16 and the first middle seal 17, a sealed first air bag 11 is formed. During the exhaust process, the exhaust pipe is not heat-sealed and is in a conductive state. The gas in the battery cell cavity 12 is discharged into the first air bag 11 through the exhaust pipe.

[0046] In some embodiments, the top sealing edge 16, the first middle sealing edge 17, and the second middle sealing edge 18 enclose the battery cell cavity 12. By enclosing the battery cell cavity 12 with the top sealing edge 16, the first middle sealing edge 17, and the second middle sealing edge 18, a sealed battery cell cavity 12 is formed. During the exhaust process, the exhaust pipe is not heat-sealed and is in a conductive state. The battery cell cavity 12 is connected to the first air bag 11 and the second air bag 13 through the exhaust pipe.

[0047] In some embodiments, the second side sealing edge 15, the top sealing edge 16, and the second middle sealing edge 18 enclose the second air bag 13. By enclosing the second air bag 13 with the second side sealing edge 15, the top sealing edge 16, and the second middle sealing edge 18, a sealed second air bag 13 is formed. During the exhaust process, the exhaust pipe is not heat-sealed and is in a conductive state. The gas in the battery cell cavity 12 is discharged into the second air bag 13 through the exhaust pipe.

[0048] In some embodiments, after the first air bag 11 and the second air bag 13 are punctured and the gas is extracted, the finished product of the soft-pack battery is obtained by heat-sealing along the first middle sealing edge 17 and the second middle sealing edge 18 and cutting off the first air bag 11 and the second air bag 13. The exhaust pipe is also heat-sealed along the first middle sealing edge 17 and the second middle sealing edge 18 here to block the exhaust pipe, and then the first air bag 11 and the second air bag 13 are cut off together with the exhaust pipe to obtain the finished product of the soft-pack battery.

[0049] The working principle of this soft-pack battery is as follows: Take a rectangular aluminum-plastic film 100 as the raw material of the outer shell, set a folding line 110 along the length direction of the aluminum-plastic film 100, set one side of the folding line 110 as the bottom film area 120, and set the other side of the folding line 110 as the cover film area 130. Lay the aluminum-plastic film 100 including the bottom film area 120 and the cover film area 130 flat on the table from top to bottom;

[0050] In the bottom film area 120, the first bulging area 121, the second bulging area 122, and the third bulging area 123 with the bulging direction upward are successively extruded from left to right. The first bulging area 121 and the third bulging area 123 are symmetrically distributed on both sides of the second bulging area 122. A number of parallel mounting grooves 140 are evenly extruded on one side of the first bulging area 121 and the third bulging area 123 close to the second bulging area 122;

[0051] In the cover film area 130, the fourth bulging area 131, the fifth bulging area 132, and the sixth bulging area 133 with the bulging direction upward are successively extruded from left to right. The fourth bulging area 131 and the sixth bulging area 133 are symmetrically distributed on both sides of the fifth bulging area 132. A number of parallel mounting grooves 140 are evenly extruded on one side of the fourth bulging area 131 and the sixth bulging area 133 close to the fifth bulging area 132;

[0052] Fold the aluminum-plastic film 100 along the folding line 110, and encapsulate the battery cell 2 with the positive electrode tab 4 and the negative electrode tab 5 between the second bulging area 122 and the fourth bulging area 131. At the same time, encapsulate the three air ducts 3 in the first placement area 171 formed by two groups of mounting grooves 140 between the first bulging area 121 and the fourth bulging area 131, and encapsulate the other three air ducts 3 in the second placement area 181 formed by two groups of mounting grooves 140 between the third bulging area 123 and the sixth bulging area 133;

[0053] Thermally press and seal the folded aluminum-plastic film 100 (the exhaust pipe is not heat-sealed and is in a conductive state);

[0054] After the formation gas in the battery cell cavity 12 is completely discharged into the first air bag 11 and the second air bag 13, puncture the first air bag 11 and the second air bag 13 to extract the gas, and thermally seal along the first middle sealing edge 17 and the second middle sealing edge 18 (heat-seal together with the exhaust pipe). Finally, cut off the first air bag 11 and the second air bag 13 along the first middle sealing edge 17 and the second middle sealing edge 18 together with the air duct 3 to obtain the finished product of the soft-pack battery.

[0055] The above is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A soft pack battery, characterized in that: It includes a shell, a battery cell, an air guide tube, a positive electrode ear and a negative electrode ear, wherein: The interior of the shell is divided into a first air bag, a battery cell cavity and a second air bag which are arranged in sequence, the first air bag and the battery cell cavity are vacuum-sealed, and the second air bag and the battery cell cavity are vacuum-sealed; The battery cell is arranged in the battery cell cavity; The air duct is located in the shell and is provided with two groups, one group of the air duct is connected between the first air bag and the battery cell cavity, and the other group of the air duct is connected between the battery cell cavity and the second air bag; The positive electrode tab and the negative electrode tab penetrate into the battery cell cavity from outside the shell, and are respectively connected to the positive electrode sheet and the negative electrode sheet of the battery cell.

2. The soft pack battery according to claim 1, characterized in that: The shell is made of an aluminum-plastic film through punching, cutting and hot pressing. The aluminum-plastic film includes a folding line, a bottom film area and a cover film area. The bottom film area and the cover film area are symmetrically arranged on both sides of the folding line. The bottom film area is provided with a first bulging area, a second bulging area and a third bulging area; the cover film area is provided with a fourth bulging area, a fifth bulging area and a sixth bulging area. After the aluminum-plastic film is folded along the folding line, the first bulging area and the fourth bulging area jointly form the first air bag, the second bulging area and the fifth bulging area jointly form a battery cell cavity, and the third bulging area and the sixth bulging area jointly form the second air bag.

3. The soft pack battery according to claim 2, characterized in that: The first bulging area, the third bulging area, the fourth bulging area and the sixth bulging area are all provided with a plurality of mutually parallel mounting grooves on a side close to the battery cell cavity; the mounting grooves of the first bulging area and the fourth bulging area are folded in half to form a first placement area; the mounting grooves of the third bulging area and the sixth bulging area are folded in half to form a second placement area; the air ducts are both placed in the first placement area and the second placement area.

4. The soft pack battery according to claim 3, characterized in that: The air guide pipe includes a straight pipe section and a curved pipe section, the straight pipe section is placed in the installation groove, the curved pipe section is arranged at one end of the straight pipe section close to the battery cell cavity, and the opening of the curved pipe section faces the bottom of the battery cell cavity.

5. The soft pack battery according to claim 4, characterized in that: The sum of the diameters of the air ducts placed in the first placement area is greater than or equal to half of the longitudinal length of the first air bag, and the sum of the diameters of the air ducts placed in the second placement area is greater than or equal to half of the longitudinal length of the second air bag.

6. The soft pack battery according to any one of claims 2 to 5, characterized in that: After heat sealing, the aluminum-plastic film forms a first side edge seal, a second side edge seal, a top edge seal, a first middle edge seal, and a second middle edge seal. The first side edge seal and the second side edge seal are respectively located on both sides of the shell, the top edge seal is located on the top of the shell, the first middle edge seal is located between the first bulging area and the second bulging area, and the second middle edge seal is located between the first bulging area and the second bulging area.

7. The soft pack battery according to claim 6, characterized in that: The first side seal, the top seal and the first middle seal form the first air bag.

8. The soft pack battery according to claim 7, characterized in that: The top seal, the first middle seal and the second middle seal form the battery cell cavity.

9. The soft pack battery according to claim 8, characterized in that: The second side seal, the top seal and the second middle seal form the second air bag.

10. The soft pack battery according to claim 9, characterized in that: After the first air bag and the second air bag are punctured and the gas is extracted, the finished soft-pack battery is obtained by heat-sealing along the first middle sealing edge and the second middle sealing edge and cutting off the first air bag and the second air bag.

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