A helium injection device for lithium batteries

Abstract

The application discloses a lithium battery helium injection device, which comprises a rack, a vacuum box arranged on the rack, a gas injection and exhaust mechanism arranged on the top of the vacuum box, a feeding mechanism in sliding connection with the rack, and a clamping mechanism, a puncturing mechanism, a stretching mechanism and a packaging mechanism arranged on the side wall of the vacuum box; the vacuum box comprises a box body fixed on the rack and a cover plate in sliding connection with the rack, the box body is fixed on the rack, and a positioning groove is arranged at the bottom of the box body; the gas injection and exhaust mechanism is arranged on the cover plate. The lithium battery helium injection device can seal the inside of a soft lithium battery and fill it with helium, and the whole helium filling process can effectively avoid the residual helium on the surface of the battery cell. The lithium battery helium injection device is used to fill the soft lithium battery with helium, and then the soft lithium battery is placed in a sealed cavity, and a helium detector is used to detect whether the battery cell is leaking. The leakage of the helium in the soft lithium battery is detected, and the packaging quality of the soft lithium battery can be accurately and quickly judged.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of soft lithium battery airtightness detection, in particular to a lithium battery helium injection device, a soft lithium battery helium injection method and a soft lithium battery airtightness detection method. BACKGROUND

[0002] Lithium battery is one of the most commonly used battery types on electric vehicles, which rapidly occupies most of the electric vehicle battery market due to its high energy density and long cycle life, therefore, the performance of lithium battery affects the overall performance of electric vehicles. At present, lithium power battery mainly has cylindrical, soft package and square three kinds, square hard shell battery is widely used by power battery manufacturers due to its high safety performance and long cycle life.

[0003] If the lithium battery is poorly sealed, it will cause serious consequences such as serious performance decline, electrolyte leakage, battery swelling and even explosion, which seriously affects the service life and safety of lithium ion battery, therefore, the performance of lithium battery sealing is very important. According to the needs of production process, the battery package must be sealed after completion.

[0004] At present, the battery evacuation and helium filling process mainly adopts the helium filling technology of reducing pressure flow control: first, the vacuum helium cup is lowered and sealed with the battery injection port; then, the battery is vacuumized, and helium is injected into the battery at a certain pressure. During the evacuation and helium filling process, the injection pressure and injection flow rate of helium are adjusted through the pressure reducing valve and the throttle valve respectively, the on-off of the helium injection pipeline is controlled by using the solenoid valve combined with the pressure gauge after helium injection, and finally the internal pressure of the battery after helium filling is close to the normal pressure. This method is suitable for cylindrical and square shell batteries, and the two kinds of batteries have the design of injection port, which is convenient to use. Soft lithium battery has no injection port design, due to the limitation of technology, at present, only hard package battery can be effectively sealed and detected, and there is no accurate and fast detection method for the airtightness detection of soft lithium battery. SUMMARY

[0005] The present application provides a battery helium injection device to solve the above technical problems.

[0006] In order to solve the above technical problems, the technical scheme of the present application is: a lithium battery helium injection device, the lithium battery helium injection device comprises a rack, a vacuum box arranged on the rack, a gas injection and exhaust mechanism arranged on the top of the vacuum box, a feeding mechanism mounted on the rack, and a clamping mechanism, a piercing mechanism, a stretching mechanism and a packaging mechanism arranged on the side wall of the vacuum box; the vacuum box comprises a box body fixed on the rack and a cover plate in sliding connection with the rack, the box body is fixed on the rack, and the bottom of the box body is provided with a positioning groove; the gas injection and exhaust mechanism is arranged on the cover plate.

[0007] Further, the upper edge of the box is provided with a sealing ring.

[0008] Further, a first support plate is arranged above the cover plate, the first support plate is connected with the cover plate through a cover plate pressurizing cylinder, the first support plate is connected with a first guide rail arranged on the rack through a first sliding block, and the first sliding block is connected with a cover plate driving cylinder.

[0009] Further, the gas injection and exhaust mechanism comprises a second support plate, the second support plate is fixedly connected with the cover plate through the first support plate, a helium injection needle driving device is fixedly arranged on the second support plate, a helium injection needle is connected below the helium injection needle driving device, and the lower end of the helium injection needle penetrates through the cover plate.

[0010] Further, a first limiting device is arranged on the helium injection needle driving device.

[0011] Further, the feeding mechanism comprises a lifting cylinder and a connecting plate, a second guide rail is fixedly arranged on the rack, the connecting plate is connected with the second guide rail through a second sliding block, a mechanical hand is connected with the lifting cylinder through the connecting plate, and the mechanical hand comprises a clamping jaw and a clamping jaw cylinder connected with the clamping jaw.

[0012] Further, a second limiting device is arranged above the lifting cylinder.

[0013] Further, the material clamping mechanism comprises a pressing plate arranged symmetrically on both sides of the positioning groove and a pressing plate driving device connected with each pressing plate.

[0014] Further, guide sleeves are arranged on both sides of the pressing plate driving device, guide columns are sleeved with the guide sleeves, and the guide columns are connected with the pressing plates.

[0015] Further, the piercing mechanism comprises at least one pair of convex and concave knife molds matched with each other, the convex and concave knife molds are symmetrically arranged on both sides of the positioning groove, the convex and concave knife molds are both connected with a piercing mechanism driving device, sealing devices are arranged on the convex and concave knife molds, the convex knife mold protrudes from the sealing device, and the concave knife mold is recessed towards the sealing device.

[0016] Further, the shapes of the convex and concave knife molds are ellipse, circle or square.

[0017] Further, the sealing device is sealing rubber.

[0018] Further, the stretching mechanism comprises at least two vacuum suction cups, and the two vacuum suction cups are symmetrically arranged on both sides of the material clamping mechanism.

[0019] Further, the packaging mechanism comprises a sealing head, a sealing head driving device, a packaging plate and a heating device, one end of the sealing head away from the material clamping mechanism is connected with the sealing head driving device, the other end of the sealing head is connected with the packaging plate, and the packaging plate is connected with the heating device.

[0020] The lithium battery helium injection device provided by the application can effectively avoid the residual of helium on the outer surface of the battery cell, and can effectively improve the precision of the helium injection device.

[0021] To solve the above technical problems, the application further provides a method for injecting helium into a soft lithium battery, which uses the lithium battery helium injection device described above.

[0022] Further, the soft lithium battery comprises one or a plurality of battery cell structures, the battery cell structure comprises a battery cell, the battery cell comprises two tabs and an intermediate region, the battery cell is externally packaged with a packaging bag, and one end of the tab extends out of the packaging bag.

[0023] Further, the packaging bag is an aluminum plastic film.

[0024] Further, the two tabs are arranged on the same side of the battery cell, or the two tabs are arranged on the two sides of the battery cell.

[0025] Further, the method for injecting helium into the soft package lithium battery comprises the following steps:

[0026] Step one, feeding and positioning: the feeding mechanism grabs the battery structure to be filled with helium, and places it at the positioning groove; the clamping mechanism clamps the battery structure; and the cover plate seals the box.

[0027] Step two, puncturing a hole: the puncturing mechanism punctures the packaging bag to form a puncture hole.

[0028] Step three, exhausting: the vacuum box is vacuumized to exhaust the air in the packaging bag, and then the puncture hole is sealed.

[0029] Step four, injecting helium: the stretching mechanism stretches the packaging bag outward, and the gas injection and exhaust mechanism injects helium into the packaging bag.

[0030] Step five, packaging: the packaging mechanism packages the packaging bag filled with helium.

[0031] Step seven, second vacuumization: the helium outside the packaging line and the helium on the outer surface of the packaging bag are exhausted, then the vacuum box is opened, the feeding mechanism takes out the battery structure filled with helium from the vacuum box, and the injection of helium is completed.

[0032] Further, it further comprises step eight, cutting: after the battery structure is taken out from the vacuum box, the packaging bag is cut.

[0033] The application also provides a method for injecting helium into a soft package lithium battery, which injects helium into the soft lithium battery by using the above lithium battery helium injection device, and then puts the soft package lithium battery into a sealed cavity to detect whether the battery structure leaks by using a helium detector.

[0034] To solve the above technical problems, the application also provides a method for detecting the air tightness of a soft package lithium battery, which injects helium into the soft lithium battery by using the above lithium battery helium injection device, and then puts the soft package lithium battery into a sealed cavity to detect whether the battery structure leaks by using a helium detector. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1a is a schematic diagram of a battery structure of a soft package lithium battery according to an embodiment of the application;

[0036] Figure 1b is a schematic diagram of a battery structure after the puncturing mechanism punctures the packaging bag according to an embodiment of the application;

[0037] Figure 1c A sealed device of a specific embodiment of the present application seals the puncture hole, and a schematic diagram of a structure of an electric core of a vacuum chuck adsorbed package bag;

[0038] Figure 1d A schematic diagram of a structure of an electric core of a lithium battery of a specific embodiment of the present application after helium injection is completed and cutting is completed;

[0039] Figure 1e A schematic diagram of a structure of an electric core of a soft package lithium battery of another specific embodiment of the present application;

[0040] Figure 2 A schematic diagram of a structure of an electric core of a lithium battery of a specific embodiment of the present application after helium injection is completed and cutting is completed;

[0041] Figure 3 A schematic diagram of a structure of an electric core of a lithium battery of a specific embodiment of the present application after helium injection is completed and cutting is completed;

[0042] Figure 4 A schematic diagram of a structure of an electric core of a lithium battery of a specific embodiment of the present application after helium injection is completed and cutting is completed;

[0043] Figure 5a A schematic diagram of a structure of an electric core of a lithium battery of a specific embodiment of the present application after helium injection is completed and cutting is completed;

[0044] Figure 5b A schematic diagram of a structure of an electric core of a lithium battery of a specific embodiment of the present application after helium injection is completed and cutting is completed. DETAILED DESCRIPTION

[0045] In order to further clarify the technical means and effects of the present application for achieving the predetermined purposes, the following describes the specific embodiments, methods, steps, structures, features and effects of the battery helium injection device according to the present application in detail in combination with the preferred embodiments and the drawings.

[0046] The foregoing and other technical contents, features and effects of the present application will be clearly presented in the detailed description of the preferred embodiments in combination with the drawings. Through the description of the specific embodiments, the technical means and effects of the present application for achieving the predetermined purposes can be more deeply and specifically understood. However, the drawings are provided for reference and illustration only, and are not used to limit the present application.

[0047] Please refer to Figure 1a , Figure 1b , Figure 1c , Figure 1d and Figure 1eAn electric cell structure 100, comprising an electric cell 101, two tabs 102 are arranged on the same side of the electric cell 101, or one tab 102 is arranged on each side of the electric cell 101, that is, one tab 102 is arranged on each side of the electric cell 101, the electric cell 101 is externally packaged with a packaging bag 103, one end of the tab 102 extends out of the packaging bag 103, the width of the packaging bag 103 is greater than the width of the electric cell 101, the part of the packaging bag 103 wider than the electric cell 101 is used for subsequent processes such as piercing, pulling, injecting helium, packaging, etc. The packaging bag 103 can be an aluminum plastic film or other packaging material.

[0048] Please refer to Figure 2 、 Figure 3 and Figure 4 A helium injection device 200 for lithium batteries can be used to inject helium into the above-mentioned electric cell structure 100,

[0049] The helium injection device for lithium batteries comprises a rack 300, a vacuum box arranged on the rack 300, a gas injection and exhaust mechanism arranged on the top of the vacuum box, a feeding mechanism mounted on the rack, and a clamping mechanism, a piercing mechanism, a stretching mechanism and a packaging mechanism arranged on the side wall of the vacuum box; the vacuum box comprises a box body 401 fixed on the rack 300 and a cover plate 402 in sliding connection with the rack 300, the box body 401 is fixed on the rack 300, and the bottom of the box body 401 is provided with a positioning groove 406; the gas injection and exhaust mechanism is arranged on the cover plate 402.

[0050] The box body 401 is fixed on the rack 300, and the bottom of the box body 401 is provided with a positioning groove 406 for positioning the electric cell structure 100.

[0051] The working principle of the helium injection device 200 of the lithium battery is as follows: the feeding mechanism grabs the battery cell structure 100, and places the battery cell structure 100 at the positioning groove 406; the clamping mechanism clamps the battery cell structure 100; the cover plate 402 slides along the rack 300 to cover the box 401, thereby sealing the vacuum box; the puncturing mechanism punctures the packaging bag 103 of the battery cell structure 100 to form a puncture hole 104; the vacuum box starts to be vacuumized; the air in the packaging bag 103 is discharged along the puncture hole 104 and is completely discharged, and then the sealing device 704 seals the puncture hole 104; the stretching mechanism slightly pulls the packaging bag 103 outward; the gas injection and exhaust mechanism injects helium into the packaging bag 103; the clamping force of the clamping mechanism is appropriately reduced, and the packaging bag 103 is inflated due to the injection of helium; then the packaging mechanism packages the packaging bag 103 along the outer edge of the battery cell 101; the second vacuumization and exhaust are performed to completely discharge the helium on the outer surface of the packaging bag 103, and the helium in the packaging bag 103 outside the packaging line 105 is completely discharged through the gas injection and exhaust mechanism, which can effectively avoid the adsorption of helium, thereby avoiding the influence of the helium molecules adsorbed on the surface of the battery cell structure 100 on the accuracy of the later leakage test, and being beneficial to improving the precision of the helium detection of the soft lithium battery; after the vacuum exhaust is completed, the vacuum box is opened, the feeding mechanism takes out the packaged battery cell structure 100 from the vacuum box, cuts the packaging bag 103, and completes the injection of helium.

[0052] The first support plate 404 is arranged above the cover plate 402, the first support plate 404 is connected with the cover plate 402 through the cover plate pressurizing cylinder 405, and the first support plate 404 is slidably connected with the first guide rail 301 arranged on the rack 300 through the first sliding block 302; the first sliding block 302 is connected with a cover plate driving cylinder (not shown in the figure), the cover plate driving cylinder drives the first sliding block 302 to drive the first support plate 404 to slide along the first guide rail 301, thereby driving the cover plate 402 to slide to the upper side of the box 401, and then the cover plate pressurizing cylinder 405 drives the cover plate 402 to press the box 401 downward, thereby sealing the vacuum box. The sealing ring 403 is arranged at the upper edge of the box 401, which is more helpful for the sealing property of the vacuum box and prevents air leakage. After the packaging mechanism packages the battery cell structure 100, the cover plate 402 returns to the original position.

[0053] The gas injection and exhaust mechanism comprises a second support plate 1001 fixedly connected with the cover plate 402 through the first support plate 404; the second support plate 1001 is fixed with a helium injection needle driving device 1002, and the helium injection needle driving device 1002 is connected with a helium injection needle 1003 below; the lower end of the helium injection needle 1003 penetrates through the cover plate 402. When the cover plate 402 covers the box body 401, the helium injection needle 1003 is opposite to the positioning groove 406 in the box body 401, that is, opposite to the upper part of the battery cell structure 100 to be filled with helium. The helium injection needle driving device 1002 is provided with a first limiting device 1004 for limiting the movement area of the helium injection needle 1003, so as to ensure that the helium injection needle 1003 accurately penetrates the packaging bag 103 and avoids penetrating the battery cell 101.

[0054] The working principle of the gas injection and exhaust mechanism is as follows: the helium injection needle driving device 1002 drives the helium injection needle 1003 to penetrate the packaging bag 103, and the helium injection needle 1003 injects helium into the packaging bag 103. After the battery cell structure 100 is packaged by the packaging mechanism, the second vacuum exhaust is performed, and the helium in the packaging bag 103 outside the packaging line 105 is completely exhausted by the gas injection and exhaust mechanism, which can effectively avoid the adsorption of helium, thereby avoiding the influence of the helium molecules adsorbed on the surface of the battery cell structure 100 on the accuracy of the later leakage test, and improving the precision of the helium detection of the soft lithium battery.

[0055] Please refer to Figure 2 , Figure 3 and Figure 4 , the feeding mechanism is used for conveying the battery cell structure 100. The feeding mechanism comprises a lifting cylinder 501 and a connecting plate 502, the rack 300 is fixed with a second guide rail 303, and the connecting plate 502 is slidably connected with the second guide rail 303 through a second sliding block 304. The lifting cylinder 501 is connected with a mechanical hand through the connecting plate 502, and the mechanical hand comprises a clamping jaw and a clamping jaw cylinder 505 connected with the clamping jaw. The lifting cylinder 501 is provided with a second limiting device 506 above, which is used for limiting the lifting area of the mechanical hand, so as to limit the position of the battery cell structure 100.

[0056] The working principle of the feeding mechanism is as follows: the clamping jaw cylinder 505 drives the clamping jaw to clamp the battery cell structure 100, slides along the second guide rail 303 to the upper side of the box 401, the lifting cylinder 501 drives the mechanical hand to descend through the connecting plate 502, sends the battery cell structure 100 to the positioning groove 406 in the vacuum box, and the feeding mechanism returns to the original position; after the helium injection process is completed, the clamping jaw cylinder 505 drives the clamping jaw to clamp the battery cell structure 100, the lifting cylinder 501 drives the mechanical hand to ascend, and the battery cell structure 100 is transferred to the next process. The mechanical hand can be provided with two, which facilitates the balance of the material during the grabbing process.

[0057] Please refer to Figure 2 , Figure 3 and Figure 4 , the material clamping mechanism includes two pressing plates 601 symmetrically arranged on both sides of the positioning groove 406 and a pressing plate driving device 602 connected with each pressing plate 601; the pressing plate driving device 602 drives the two pressing plates 601 to move towards each other, clamping the battery cell structure 100, and the position of the pressing plate 601 is above the positioning groove 406. The part of the packaging bag 103 which is wider than the pressing plate 601 is used for subsequent process of piercing and pulling open.

[0058] Please refer to Figure 4 , guide sleeves 603 are arranged on both sides of the pressing plate driving device 602, guide columns 604 are sleeved with the guide sleeves 603, the guide columns 604 are connected with the pressing plates, and the pressing plate driving device 602 drives the guide sleeves 603 to slide along the guide columns 604, which can effectively ensure the stable movement of the pressing plates.

[0059] Please refer to Figure 1b and 1c , Figure 2 , Figure 3 and Figure 4 , in combination with Figure 5a and Figure 5b , Figure 1b is a schematic view of the battery cell structure 100 after the piercing mechanism pierces the packaging bag 103; Figure 1c is a schematic view of the battery cell structure in which the sealing device 704 seals the piercing hole 104 and the vacuum suction cup 801 adsorbs the packaging bag 103; Figure 4is a structure diagram of a piercing mechanism of a helium injection device for lithium batteries after piercing a packaging bag 103. The piercing mechanism is used to pierce the packaging bag 103 to generate a piercing hole 104 on the packaging bag 103, and the piercing hole 104 is used to discharge gas in the packaging bag 103. The piercing mechanism includes at least one pair of convex cutter dies 701 and concave cutter dies 702 that are symmetrically arranged on both sides of the positioning groove 406 and point to the upper edge of the packaging bag 103. The convex cutter dies 701 and the concave cutter dies 702 are connected with a piercing mechanism driving device 703, and the convex cutter dies 701 and the concave cutter dies 702 are provided with sealing devices 704. The convex cutter dies 701 protrude from the sealing devices 704, and the concave cutter dies 702 are recessed to the sealing devices 704. The convex cutter dies 701 and the concave cutter dies 702 can be any shape such as an ellipse, a circle, or a square. The sealing devices 704 can be sealing rubbers, and the sealing devices 704 are used to seal the holes cut by the convex cutter dies 701 and the concave cutter dies 702. The convex cutter dies 701 and the sealing rubbers are organically combined, and the concave cutter dies 702 and the sealing rubbers are organically combined to realize a set of devices that have both piercing and sealing functions.

[0060] The working principle of the piercing mechanism is as follows: the piercing mechanism driving device 703 drives the convex cutter dies 701 and the concave cutter dies 702 to move towards the battery cell structure 100, and the convex cutter dies 701 and the concave cutter dies 702 work in cooperation to pierce the upper edge of the packaging bag 103 to generate a piercing hole 104. The piercing hole 104 has the same shape as the convex cutter dies 701 and the concave cutter dies 702, and the piercing hole 104 is used to discharge gas in the packaging bag 103 during the vacuum pumping process of the vacuum box. After the piercing hole 104 is generated, the convex cutter dies 701 and the concave cutter dies 702 return to the original position, the vacuum box is pumped, and the gas in the packaging bag 103 is discharged through the piercing hole 104. After the gas in the packaging bag 103 is discharged, the piercing mechanism driving device 703 drives the convex cutter dies 701 and the concave cutter dies 702 to move towards the battery cell structure 100, and the sealing devices 704 on the convex cutter dies 701 and the concave cutter dies 702 seal the piercing hole 104 to prevent helium in the packaging bag 103 from leaking during the helium injection process.

[0061] Please refer to Figure 2 , Figure 3 and Figure 4The stretching mechanism comprises at least two vacuum suction cups 801 and a vacuum suction cup driving device 802 connected with the vacuum suction cups 801, and the positions of the vacuum suction cups 801 are directed to the middle position of the packaging bag 103; the stretching mechanism can also be provided with two vacuum suction cups 801, and the two vacuum suction cups 801 are symmetrically arranged on both sides of the material clamping mechanism, that is, on both sides of the lithium cell structure 100 to be filled with helium.

[0062] The working principle of the stretching mechanism is as follows: the vacuum suction cup driving device 802 drives the vacuum suction cup 801 to adsorb the outer surface of the packaging bag 103, and then the vacuum suction cup driving device 802 drives the vacuum suction cup 801 to pull the packaging bag 103 apart by a distance, so that the packaging bag 103 is deformed to a certain extent, and the helium gas is injected into the packaging bag 103.

[0063] Please refer to Figure 1d and Figure 4 , Figure 1d is a schematic view of the lithium cell structure 100 after the helium filling and cutting are completed; the packaging mechanism is used for packaging the lithium cell structure 100 after the helium gas is injected. The packaging mechanism comprises a sealing head 901, a sealing head driving device 902, a packaging plate 903 and a heating device (not shown in the figure), one end of the sealing head 901 away from the material clamping mechanism is connected with the sealing head driving device 902, the other end of the sealing head 901 is connected with the packaging plate 903, the packaging plate 903 is connected with the heating device, and the heating device is used for heating the packaging plate 903. The sealing head driving device 902 drives the sealing head 901 to drive the sealing head driving device 902 to move towards the packaging bag 103, so as to realize the heat sealing of the packaging bag 103, and the packaging line 105 is along the outer edge of the lithium cell; the puncture hole 104 generated by the puncture mechanism and the position of the packaging bag 103 adsorbed by the vacuum suction cup 801 of the stretching mechanism are all outside the packaging line 105, and after the lithium cell structure 100 is packaged by the packaging mechanism, the air tightness of the packaging bag 103 can be effectively guaranteed.

[0064] The lithium battery helium injection device 200 provided by the application can fill helium in the soft lithium battery in a sealed manner, and the whole helium filling process can effectively avoid the residual helium on the outer surface of the lithium cell. The lithium battery helium injection device is used to fill helium in the soft lithium battery, and then the soft lithium battery is placed in a sealed cavity, and a helium detector is used to detect whether the lithium cell leaks. The leakage of helium in the soft lithium battery can accurately and quickly judge the packaging quality of the soft lithium battery.

[0065] A method for injecting helium into a soft lithium battery, wherein the lithium battery helium injection device 200 is used to inject helium into the soft lithium battery, and the method comprises the following steps:

[0066] Step one, feeding: the feeding mechanism grabs the battery structure 100 and places it in the positioning groove, and the clamping mechanism clamps the battery structure 100, and the cover plate 402 covers the box 401;

[0067] Step two, piercing: the piercing mechanism pierces the packaging bag 103 to form a piercing hole 104;

[0068] Step three, exhaust: the vacuum box is evacuated, and the air in the battery structure 100 is exhausted along the piercing hole 104 and is exhausted,

[0069] Step four, the sealing device 704 seals the piercing hole 104;

[0070] Step five, helium injection: the stretching mechanism pulls the packaging bag 103 of the battery structure 100 outward by a distance, and the packaging bag 103 deforms to a certain extent, the helium injection needle injects helium into the packaging bag 103, and the pressure of the clamping mechanism is reduced, and the packaging bag 103 is inflated due to the injection of helium;

[0071] Step six, packaging: the packaging mechanism packages the packaging bag 103 along the outer edge of the battery 101, which can be packaged by heat sealing; the packaging line 105 is along the edge of the battery, the piercing hole 104, and the packaging bag position adsorbed by the vacuum chuck 801 are all outside the packaging line 105, and after the packaging bag 103 is further packaged, the air tightness of the battery structure 100 can be effectively guaranteed.

[0072] Step seven, second vacuum exhaust: the residual helium in the packaging bag 103 outside the packaging line 105 is exhausted by the gas injection and exhaust mechanism, which can effectively avoid helium adsorption, thereby avoiding the influence of the helium molecules adsorbed on the surface of the battery structure 100 on the accuracy of the later leak detection, and improving the precision of the soft lithium battery helium detection; after the vacuum exhaust is completed, the helium injection needle 1003 is withdrawn, and then the vacuum box is opened; the helium in the outer surface of the packaging bag 103 can also be completely exhausted, which can effectively avoid the adsorption of helium on the inner and outer surfaces of the packaging bag 103, thereby avoiding the influence of the helium molecules adsorbed on the surface of the battery structure 100 on the accuracy of the later leak detection, and improving the precision of the soft lithium battery helium detection; after the vacuum exhaust is completed, the gas injection and exhaust mechanism, the piercing mechanism, and the stretching mechanism are all returned to the original position;

[0073] Step eight, cutting: the vacuum box is opened, the mechanical hand of the feeding mechanism clamps the packaging bag 103, the clamping mechanism is returned to the original position, the feeding mechanism takes out the packaged battery structure 100 from the vacuum box, and the battery structure 100 is conveyed to the cutting station, and the packaging bag is cut, which can also be cut by a cutting tool. After cutting, the excess packaging bag 103 can be folded towards the battery 101, so that the battery structure is neat and has better air tightness.

[0074] The application discloses a kind of soft package lithium battery air tightness inspection method, using above-mentioned lithium battery helium injection device to soft lithium package battery helium is filled, then soft package lithium battery is placed into to closed cavity, whether the cell is detected by helium detector leakage.Detect the helium leakage of soft package lithium battery, the quality of the packaging of soft package lithium battery can be accurately, quickly judged.

[0075] The above is only the preferred embodiment of the application, not any form of limitation on the application, although the application has been disclosed as above with the preferred embodiment, however, not to limit the application, any person skilled in the art, without departing from the technical solution of the application, can use the above disclosed technical content to make some changes or modifications for equivalent embodiments of equivalent changes, but as long as it does not deviate from the technical solution of the application, according to the technical essence of the application, any simple modification, equivalent change and modification of the above embodiments are still within the scope of the technical solution of the application.

Claims

1. A lithium battery helium injection device, characterized by, The helium injection device of the lithium battery comprises a rack, a vacuum box arranged on the rack, a gas injection and exhaust mechanism arranged on the top of the vacuum box, a feeding mechanism mounted on the rack, and a clamping mechanism, a piercing mechanism, a stretching mechanism and a packaging mechanism arranged on the side wall of the vacuum box; the vacuum box comprises a box body fixed on the rack and a cover plate in sliding connection with the rack, the box body is fixed on the rack, and the bottom of the box body is provided with a positioning groove; the gas injection and exhaust mechanism is arranged on the cover plate; a first support plate is arranged above the cover plate, the first support plate is connected with the cover plate through a cover plate pressurizing cylinder, and the first support plate is in sliding connection with a first guide rail arranged on the rack through a first sliding block; the first sliding block is connected with a cover plate driving cylinder; the gas injection and exhaust mechanism comprises a second support plate, the second support plate is fixedly connected with the cover plate through the first support plate; a helium injection needle driving device is fixedly arranged on the second support plate, a helium injection needle is connected below the helium injection needle driving device, and the lower end of the helium injection needle penetrates through the cover plate; the piercing mechanism comprises at least one pair of convex and concave knife molds matched with each other, the convex and concave knife molds are symmetrically arranged on both sides of the positioning groove, the convex and concave knife molds are both connected with a piercing mechanism driving device, sealing devices are arranged on the convex and concave knife molds, the convex knife mold protrudes from the sealing device, and the concave knife mold is recessed to the sealing device; the stretching mechanism comprises at least two vacuum suction cups, and the two vacuum suction cups are symmetrically arranged on both sides of the clamping mechanism.

2. The lithium battery helium injection device of claim 1, wherein, A sealing ring is arranged on the upper edge of the box body.

3. The lithium battery helium injection device of claim 1, wherein, A first limiting device is arranged on the helium injection needle driving device.

4. The lithium battery helium injection device of claim 1, wherein, The feeding mechanism comprises a lifting cylinder and a connecting plate, a second guide rail is fixed on the rack, the connecting plate is in sliding connection with the second guide rail through a second sliding block, the lifting cylinder is connected with a mechanical hand through the connecting plate, and the mechanical hand comprises a clamping jaw and a clamping jaw cylinder connected with the clamping jaw.

5. The lithium battery helium injection device of claim 4, wherein, A second limiting device is arranged above the lifting cylinder.

6. The lithium battery helium injection device of claim 1, wherein, The clamping mechanism comprises pressure plates symmetrically arranged on both sides of the positioning groove and pressure plate driving devices connected with the pressure plates.

7. The lithium battery helium injection device of claim 6, wherein, Guide sleeves are arranged on both sides of the pressure plate driving devices, guide columns are sleeved on the guide sleeves, and the guide columns are connected with the pressure plates.

8. The lithium battery helium injection device of claim 1, wherein, The shapes of the convex and concave knife molds are ellipse, circle or square.

9. The lithium battery helium injection device of claim 1, wherein, The packaging mechanism comprises a sealing head, a sealing head driving device, a packaging plate and a heating device, one end of the sealing head away from the clamping mechanism is connected with the sealing head driving device, the other end of the sealing head is connected with the packaging plate, and the packaging plate is connected with the heating device.

10. A method for helium injection of a soft-pack lithium battery, characterized by, The lithium battery helium injection device of any one of claims 1-9 is used for injecting helium into a soft package lithium battery.

11. The method of Claim 10, wherein the soft-pack lithium battery is injected with helium. The soft package lithium battery comprises one or a plurality of cell structures, the cell structure comprises a cell, the cell comprises two tabs and an intermediate region, the cell is externally packaged with a packaging bag, and one end of the tab extends out of the packaging bag.

12. The method of helium injection of a pouch lithium battery of claim 11, wherein, The packaging bag is an aluminum plastic film.

13. The method of Claim 11, wherein the soft-pack lithium battery is injected with helium. The two tabs are arranged on the same side of the cell, or the two tabs are arranged on the two sides of the cell respectively. The two tabs are arranged on the same side of the cell, or the two tabs are arranged on the two sides of the cell respectively.

14. The method of helium injection of a pouch lithium battery of claim 11, wherein, It comprises the following steps: Step one, feeding and positioning: the feeding mechanism grabs the battery structure to be filled with helium, and places it at the positioning groove; the clamping mechanism clamps the battery structure; and the cover seals the box; Step two, puncturing hole: the puncturing mechanism punctures the packaging bag to generate a puncturing hole; Step three, exhaust: the vacuum box is vacuumized to exhaust the air in the packaging bag, and then the puncturing hole is sealed; Step four, helium injection: the stretching mechanism stretches the packaging bag outward, and the gas injection and exhaust mechanism injects helium into the packaging bag; Step five, packaging: the packaging mechanism packages the packaging bag that has been injected with helium; Step seven, second vacuumization: the helium outside the packaging line and the helium on the surface of the packaging bag are completely exhausted, and then the vacuum box is opened; the feeding mechanism takes out the battery structure after helium injection from the vacuum box, and the helium injection is completed.

15. The method of helium injection of a pouch lithium battery of claim 14, wherein, It further comprises step eight, cutting: after the battery structure is taken out from the vacuum box, the packaging bag is cut.

16. A method of inspecting the air tightness of a pouch lithium battery, characterized by, The lithium battery helium injection device of any one of claims 1-9 is used to fill helium in soft lithium battery, and then the soft lithium battery is put into a closed cavity, and a helium detector is used to detect whether the battery has a leak and detect the helium leakage of the soft lithium battery, so that the packaging quality of the soft lithium battery can be accurately and quickly judged.

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