Method for manufacturing a lithium battery cell

Abstract

The present invention provides a method for manufacturing a lithium battery core, and the steps thereof include: providing an outer bag, a plurality of electrode sheets and a conduit. At least a part of the edge of the outer bag is pressed to form a sealing edge, and an electrode chamber is formed inside the outer bag. The electrode sheets are accommodated in the electrode chamber. The sealing edge is strip-shaped and an air chamber is formed within the sealing edge. The air chamber communicates with the electrode chamber. The conduit is clamped in the sealing edge. The two ends of the conduit are respectively an inner end and an outer end. The inner end communicates with the air chamber and there is a spacing between the inner end and the electrode chamber. The outer end is exposed outside the outer bag; an electrolyte is injected into the electrode chamber through the conduit; the air chamber is pressed to form a secondary sealing edge; the secondary sealing edge is cut to remove the conduit. Thereby, the structure of the sealing edge is uniform so as to avoid the connection of different structures, and thus when the sealing edge is folded, no gap will be generated between different structures.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a lithium battery core, and more particularly to a method for manufacturing a soft-pack lithium battery core. Background Art

[0002] The general method for manufacturing a lithium battery core nowadays is roughly as follows: First, a stack of electrodes is placed into a packaging bag, the periphery of the packaging bag is sealed, and then the air inside the packaging bag is exhausted. Next, an electrolyte is injected into the packaging bag. In the foregoing manufacturing method, air can be exhausted and the electrolyte can be filled through the pores reserved on the sealed periphery. However, this manufacturing method is not easy to process because the pores are difficult to control, and leakage is likely to occur at the sealed edge.

[0003] Another feasible manufacturing method is to place the electrodes and the electrolyte into a larger packaging bag, place the electrodes and the electrolyte on one side inside the packaging bag and then seal the packaging bag. Next, air is squeezed into the other side inside the packaging bag, and then the packaging bag is transversely heat-sealed to separate the air and the electrodes in different spaces. Then, the part of the packaging bag that accommodates the air is cut off. This manufacturing method requires discarding the excess electrolyte and packaging bag waste, which not only increases the material cost but also increases the cost of treating toxic waste. Summary of the Invention

[0004] The present invention provides a method for manufacturing a soft-pack lithium battery core to solve the above problems existing in the prior art.

[0005] The present invention provides a method for manufacturing a lithium battery core, and its steps include: Step a: providing an outer bag, several electrode sheets, and a conduit. At least a part of the edge of the outer bag is pressed to form a sealed edge, and an electrode chamber is formed inside the outer bag. The electrode sheets are accommodated in the electrode chamber. The sealed edge is strip-shaped and an air chamber is formed inside the sealed edge. The air chamber communicates with the electrode chamber. The conduit is clamped in the sealed edge. The two ends of the conduit are respectively an inner end and an outer end. The inner end communicates with the air chamber and there is a spacing between the inner end and the electrode chamber. The outer end is exposed outside the outer bag; Step b: injecting an electrolyte into the electrode chamber through the conduit; Step c: hot-pressing and sealing the air chamber to form a secondary sealed edge; Step d: cutting the secondary sealed edge to remove the conduit.

[0006] In the method for manufacturing a lithium battery core of the present invention, the inner end of the conduit is connected to the edge of the air chamber. The air chamber is conical and has a tip and a blunt end. The blunt end is connected to the electrode chamber, and the tip is connected to the conduit. The tip of the air chamber is connected to the inner end of the conduit. A spacing is formed between the tip of the air chamber and the outer edge of the sealed edge. The sealed edge includes an air chamber sealed edge located between the air chamber and the outer edge of the sealed edge, and the conduit is clamped in the air chamber sealed edge.

[0007] In the method for manufacturing a lithium battery core of the present invention, the steps further include exhausting the gas inside the electrode chamber through the conduit. Connect the outer end of the conduit to a negative pressure device to exhaust the gas inside the electrode chamber.

[0008] The manufacturing method of the lithium battery cell of the present invention connects the outer end of the conduit to a liquid injection device to inject the electrolyte into the electrode chamber.

[0009] In the manufacturing method of the lithium battery cell of the present invention, the conduit is located outside the secondary edge sealing.

[0010] The manufacturing method of the lithium battery cell of the present invention is easy to degas and inject liquid through the conduit, and after the gas chamber is sealed as the secondary edge sealing, the conduit can be completely removed from the edge sealing, thereby making the structure of the edge sealing uniform to avoid the connection of different structures, so that when the edge sealing is folded, no gap will be generated between different structures. Description of the Drawings

[0011] Figure 1 is a flowchart of the manufacturing method of the lithium battery cell of the preferred embodiment of the present invention.

[0012] Figure 2 is a schematic diagram of the semi-finished battery cell in the manufacturing method of the lithium battery cell of the preferred embodiment of the present invention.

[0013] Figure 3 is another schematic diagram of the semi-finished battery cell in the manufacturing method of the lithium battery cell of the preferred embodiment of the present invention.

[0014] Figure 4 is a schematic diagram of the degassing step in the manufacturing method of the lithium battery cell of the preferred embodiment of the present invention.

[0015] Figure 5 is a schematic diagram of the liquid injection step in the manufacturing method of the lithium battery cell of the preferred embodiment of the present invention.

[0016] Figure 6 is a schematic diagram of the sealing step in the manufacturing method of the lithium battery cell of the preferred embodiment of the present invention.

[0017] Figure 7 is another schematic diagram of the sealing step in the manufacturing method of the lithium battery cell of the preferred embodiment of the present invention.

[0018] Figure 8 is a schematic diagram of the trimming step in the manufacturing method of the lithium battery cell of the preferred embodiment of the present invention.

[0019] Figure 9 is a schematic diagram of the lithium battery cell manufactured by the manufacturing method of the lithium battery cell of the preferred embodiment of the present invention.

[0020] In the figure:

[0021] 100: Outer bag; 101: Electrode chamber; 102: Gas chamber; 102a: Tip; 102b: Blunt end; 110: Sealing edge; 111: Gas chamber sealing edge; 112: Secondary sealing edge; 200: Electrode sheet; 210: Tab; 300: Tube; 310: Inner end; 320: Outer end; a - e: Steps. Detailed implementation manner

[0022] Refer to Figure 1 , a preferred embodiment of the present invention provides a method for manufacturing a lithium battery core, which includes the following steps.

[0023] Refer to Figure 1 And Figure 2 , first, in step a, a battery core semi-finished product is provided, which includes an outer bag 100, several electrode sheets 200, and a tube 300.

[0024] At least a part of the edge of the outer bag 100 is pressed to form a sealing edge 110. In this embodiment, the edge of the outer bag 100 is rectangular and has four side edges, and at least two of the side edges are connected to form the sealing edge 110. In this embodiment, the four side edges of the edge of the outer bag 100 are connected to form the sealing edge 110. Moreover, the sealing edge 110 is strip-shaped and forms an electrode chamber 101 inside the outer bag 100. The inner part of the sealing edge 110 is not pressed to form a gas chamber 102, and the gas chamber 102 communicates with the electrode chamber 101. Specifically, the sealing edge 110 includes a gas chamber sealing edge 111 located between the gas chamber 102 and the outer edge of the sealing edge 110, and a distance is formed between the gas chamber 102 and the outer edge of the sealing edge 110 through the gas chamber sealing edge 111.

[0025] Each of the electrode sheets 200 is stacked and arranged, and the stacked electrode sheets 200 are accommodated in the electrode chamber 101. The stacked electrode sheets 200 are provided with a pair of tabs 210. Each electrode sheet 200 is respectively connected to the corresponding pole, and each tab 210 is respectively clamped in the sealing edge 110 of the outer bag 100 and penetrates through the outer bag 100. Preferably, the pair of tabs 210 are arranged on the same side edge of the edge of the outer bag 100. Moreover, the gas chamber 102 and the pair of tabs 210 are respectively arranged on different side edges of the edge of the outer bag 100.

[0026] The tube 300 is clamped in the sealing edge 110. The two ends of the tube 300 are respectively an inner end 310 and an outer end 320. The inner end 310 communicates with the gas chamber 102 and has a distance from the electrode chamber 101. The outer end 320 is exposed outside the outer bag 100. Specifically, the tube 300 is clamped in the gas chamber sealing edge 111. The inner end 310 of the tube 300 is preferably connected to the edge of the gas chamber 102. However, the inner end 310 of the tube 300 can also penetrate into the gas chamber 102, but there still needs to be a distance between the inner end 310 of the tube 300 and the electrode chamber 101.

[0027] As shown Figure 3 in the figure, the present invention does not limit the shape of the gas chamber 102. However, the gas chamber 102 is preferably conical with a tip 102a and a blunt end 102b. The blunt end 102b of the gas chamber 102 is connected to the electrode chamber 101, and the tip 102a of the gas chamber 102 is connected to the inner end 310 of the conduit 300. This can reduce the flow resistance caused by the shape of the gas chamber 102 during the degassing and liquid injection processes; in addition, it can also prevent the formation of dead corners in the gas chamber 102, thereby avoiding the electrolyte remaining in the dead corners of the gas chamber 102.

[0028] Referring to Figure 1 , Figure 4 and Figure 5 , following step a, in the liquid injection step b, an electrolyte is injected into the electrode chamber 101 through the conduit 300. Preferably, in this embodiment, an additional degassing step e may be included between step a and step b. In step e, the gas in the electrode chamber 101 is discharged through the conduit 300. In step e, the outer end 320 of the conduit 300 is connected to a negative pressure device (not shown in the figure) to discharge the gas in the electrode chamber 101. The present invention does not limit the form of the negative pressure device, and the negative pressure device can be an air pump or a syringe, etc., which can generate a pressure difference in the gas. In step b, the outer end 320 of the conduit 300 is connected to a liquid injection device (not shown in the figure) to inject the electrolyte into the electrode chamber 101. The present invention does not limit the form of the liquid injection device, and it can be a liquid pump and its pipeline is connected to the conduit 300 to pump the electrolyte.

[0029] Referring to Figure 1 and Figure 6 , following step b, in the sealing step c, the gas chamber 102 is hot-pressed and sealed to form a secondary seal 112. In this embodiment, the inner end 310 of the conduit 300 is connected to the edge of the gas chamber 102. Therefore, after the gas chamber 102 is pressed, the conduit 300 is located outside the secondary seal 112. However, when the inner end 310 of the conduit 300 penetrates into the gas chamber 102, the inner end 310 of the conduit 300 is located inside the secondary seal 112 after the gas chamber 102 is pressed, but there still needs to be a distance between the inner end 310 of the conduit 300 and the electrode chamber 101. Furthermore, as shown Figure 7 in the figure, only a part of the gas chamber 102 can be pressed to form the secondary seal 112 that closes the electrode chamber 101.

[0030] Referring to Figure 1 and Figures 6 to 9 , following step c, in the trimming step d, the secondary seal 112 is trimmed to remove the conduit 300. Moreover, the gas chamber 102 and the pair of electrode tabs 210 are respectively arranged on different sides of the edge of the outer bag 100. Therefore, the conduit 300 can be removed while avoiding the electrode tabs 210.

[0031] The manufacturing method of the battery core of the present invention facilitates degassing and liquid injection through the conduit 300, and after the air chamber 102 is sealed with the secondary seal 112, the conduit 300 can be completely removed from the seal 110. The manufacturing method of the battery core of the present invention described above is made into Figure 9 the lithium battery core shown, thereby making the structure of the seal 110 of the lithium battery core uniform to avoid the connection of different structures (i.e., the outer bag 100 itself and the conduit 300). Therefore, when the seal 110 is folded, stress concentration will not cause gaps at the connection between different structures.

[0032] The above-described embodiments are merely preferred embodiments cited to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are within the protection scope of the present invention. The protection scope of the present invention is subject to the claims.

Claims

1. A method for manufacturing a battery cell, characterized in that, Including: Step a: Provide an outer bag, several electrode sheets, and a catheter. At least a part of the edge of the outer bag is pressed to form a sealing edge, and an electrode chamber is formed around the inner periphery of the outer bag. Each of the electrode sheets is accommodated in the electrode chamber. The sealing edge is strip-shaped, and an air chamber is formed within the sealing edge. The air chamber communicates with the electrode chamber. The catheter is clamped in the sealing edge. Two ends of the catheter are respectively an inner end and an outer end. The inner end communicates with the air chamber and there is a spacing between the inner end and the electrode chamber. The outer end is exposed outside the outer bag, and another spacing is formed between the air chamber and the outer edge of the sealing edge; Step b: Inject an electrolyte into the electrode chamber through the catheter; Step c: Press the air chamber to form a secondary sealing edge; and Step d: Cut the sealing edge together with the secondary sealing edge to remove the catheter.

2. The manufacturing method of the battery cell according to claim 1, characterized in that, The inner end of the catheter is connected to the edge of the air chamber.

3. The manufacturing method of the battery cell according to claim 1, characterized in that, The air chamber is conical and has a tip and a blunt end. The blunt end is connected to the electrode chamber, and the tip is connected to the catheter.

4. The manufacturing method of the battery cell according to claim 3, characterized in that, The tip of the air chamber is connected to the inner end of the catheter.

5. The method for manufacturing a battery cell according to claim 1, wherein, The sealing edge includes an air chamber sealing edge located between the air chamber and the outer edge of the sealing edge, and the catheter is clamped in the air chamber sealing edge.

6. The method for manufacturing a battery cell according to claim 1, characterized in that, Between step a and step b, there is also a step e of discharging the gas in the electrode chamber through the catheter.

7. The manufacturing method of the battery cell according to claim 6, characterized in that, In step e, connect the outer end of the catheter to a negative pressure device to discharge the gas in the electrode chamber.

8. The manufacturing method of the battery cell according to claim 1, characterized in that, In step b, connect the outer end of the catheter to a liquid injection device to inject the electrolyte into the electrode chamber.

9. The method for manufacturing a battery cell according to claim 1, characterized in that, In step c, the catheter is located outside the secondary sealing edge.

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