Method for re-injecting electrolyte and secondary battery capable of re-injecting electrolyte
By forming functional pores on the aluminum sheet of the soft-pack secondary battery and coating it with insulating material, the problem of performance degradation caused by electrolyte consumption is solved, and electrolyte re-injection and sealing are achieved, thus maintaining stable battery performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LG ENERGY SOLUTION LTD
- Filing Date
- 2021-12-22
- Publication Date
- 2026-06-12
AI Technical Summary
Existing pouch-type secondary batteries suffer from electrolyte depletion during repeated charge and discharge processes, leading to performance degradation and difficulty in effectively refilling electrolyte.
By forming functional holes in aluminum sheets and coating their inner circumferential surfaces with insulating and chemically resistant materials, combined with a polymer layer, electrolyte re-injection and sealing are achieved, preventing oxidation of the aluminum sheets and current conduction.
It enables easy re-injection and drainage of the electrolyte, prevents leakage, and maintains stable battery performance.
Smart Images
Figure CN116472644B_ABST
Abstract
Description
[0001] Cross-references to related applications
[0002] This application claims priority to Korean Application No. 10-2020-0182659, filed on December 23, 2020, the entire contents of which are incorporated herein by reference. Technical Field
[0003] This invention relates to a method for re-injecting electrolyte and a secondary battery capable of re-injecting electrolyte. Background Technology
[0004] Recently, extensive research and development have been conducted on rechargeable batteries because, unlike primary batteries, they are rechargeable and offer the potential for smaller size and increased capacity. With technological advancements and increasing demands for mobile devices, the need for rechargeable batteries as a power source has surged.
[0005] Based on the shape of the battery casing, secondary batteries are classified into coin-shaped batteries, cylindrical batteries, prismatic batteries, and pouch batteries. In secondary batteries, the electrode assembly installed in the battery casing has a stacked structure of electrodes and separators, and is a rechargeable and dischargeable power generation element.
[0006] Electrode assemblies can be broadly classified into wound electrode assemblies, which are formed by inserting a separator between sheet-shaped positive and negative electrodes coated with active materials; stacked electrode assemblies, in which multiple positive and negative electrodes with separators inserted are stacked sequentially; and stacked folded electrode assemblies, which are formed by winding a stacked cell with a long separator.
[0007] Recently, pouch cells, which have a structure in which stacked or stacked folded electrode components are embedded in aluminum laminated sheets, have attracted much attention due to their low manufacturing cost, light weight, and ease of shape modification, and their usage is gradually increasing.
[0008] However, there is a problem that the electrolyte is consumed during the repeated charging and discharging of the secondary battery, resulting in a deterioration in performance.
[0009] [Prior Art Documents] (Patent Documents) Korean Patent Publication No. 10-2014-0015647 Summary of the Invention
[0010] Technical issues
[0011] One aspect of the present invention is to provide a method for re-injecting electrolyte and a secondary battery capable of re-injecting electrolyte, wherein the method facilitates the re-injection of electrolyte.
[0012] Technical solution
[0013] According to an embodiment of the present invention, a method for re-injecting electrolyte is a method for re-injecting electrolyte into an electrode assembly and a secondary battery in which the electrolyte is housed in a pouch. The pouch may include an aluminum sheet having functional pores and a polymer layer laminated on the aluminum sheet. The method may include a re-injection step of injecting additional electrolyte into the pouch through the functional pores by opening them, and a sealing step of sealing the functional pores after the re-injection step.
[0014] Furthermore, according to one embodiment of the present invention, a secondary battery capable of refilling electrolyte includes an electrode assembly and a pouch housing the electrode assembly, wherein electrodes and separators are alternately stacked and bonded to each other, and the pouch includes an aluminum sheet and a polymer layer laminated with the aluminum sheet, wherein functional pores are formed in the aluminum sheet, and a coating portion is provided on the inner circumferential surface of the functional pores in the aluminum sheet.
[0015] Beneficial effects
[0016] According to the present invention, the secondary battery uses a pouch with a polymer layer laminated on an aluminum sheet having functional pores, thereby facilitating the reinjection of electrolyte through the functional pores. In the secondary battery, gas inside the pouch can pass through the functional pores through the polymer layer and be easily discharged to the outside. Attached Figure Description
[0017] Figure 1 This is a plan view showing the state of a secondary battery before the electrode assembly is housed in a pouch, as described in an embodiment of the present invention, using a method for re-injecting electrolyte.
[0018] Figure 2 It is along Figure 1 The cross-sectional view taken by line AA′ in the diagram.
[0019] Figure 3 This is a plan view illustrating a method for re-injecting electrolyte into a secondary battery according to an embodiment of the present invention.
[0020] Figure 4 It is along Figure 3 The cross-sectional view taken from line BB′ in the diagram.
[0021] Figure 5 It is shown Figure 4 An enlarged cross-sectional view of region C in the image.
[0022] Figure 6 This is a cross-sectional view illustrating the concept of a re-injection step in a method for re-injecting electrolytes according to an embodiment of the present invention.
[0023] Figure 7 This is a cross-sectional view illustrating the concept of a sealing process applied in a method for re-injecting electrolyte according to an embodiment of the present invention. Detailed Implementation
[0024] The objectives, beneficial effects, and technical features of this invention will be illustrated by the embodiments described below with reference to the accompanying drawings. It should be noted that identical or similar components in the drawings are indicated by the same reference numerals wherever possible, even if they are shown in different drawings. This invention may be implemented in different forms and should not be construed as limited to the embodiments described herein. Furthermore, detailed descriptions of unnecessary related well-known techniques that might obscure the subject matter of this invention will be excluded.
[0025] Re-injection of electrolytes
[0026] Figure 1 This is a plan view showing the state of a secondary battery before the electrode assembly is housed in a pouch, according to a method for re-injecting electrolyte applied according to an embodiment of the present invention. Figure 2 It is along Figure 1 The cross-sectional view taken by line AA′ in the diagram. Figure 3 This is a plan view illustrating a method for re-injecting electrolyte into a secondary battery according to an embodiment of the present invention. Figure 4 It is along Figure 3 The cross-sectional view taken from line BB′ in the diagram. Figure 5 It is shown Figure 4 An enlarged cross-sectional view of region C in the image.
[0027] Figure 6 This is a cross-sectional view illustrating the concept of a re-injection step in a method for re-injecting electrolytes according to an embodiment of the present invention. Figure 7 This is a cross-sectional view illustrating the concept of a sealing process applied in a method for re-injecting electrolyte according to an embodiment of the present invention. Figure 6 and Figure 7 By magnification Figure 4 The diagram in region C illustrates corresponding examples of the re-injection and sealing processes.
[0028] like Figures 1 to 7 As shown, according to an embodiment of the present invention, the method for re-injecting electrolyte into a secondary battery is a method for re-injecting electrolyte into a secondary battery 100, wherein the electrode assembly 120 and the electrolyte of the secondary battery 100 are housed in a pouch 110. The pouch 110 includes an aluminum sheet 113 having functional holes 113a formed therein, and polymer layers 111 and 116 laminated on the aluminum sheet 113. The method includes a re-injection step of injecting additional electrolyte into the pouch 110 through the functional holes 113a, and a sealing step of sealing the functional holes 113a after the re-injection step.
[0029] Furthermore, such as Figures 1 to 5As shown, the method of re-injecting electrolyte into a secondary battery 100 according to an embodiment of the present invention is a method of re-injecting electrolyte into an electrode assembly 120 assembled by alternately stacking electrodes and a separator, and into a secondary battery 100 in which the electrolyte is contained in a pouch 110.
[0030] The flexible pack 110 includes an aluminum sheet 113 with functional holes 113a and polymer layers 111 and 116 laminated on the aluminum sheet 113. A coating portion 113b may be formed on the inner circumferential surface of the functional holes 113a in the aluminum sheet 113. The coating portion 113b may contain an insulating and chemically resistant material. Therefore, after forming holes in the portions of polymer layers 111 and 116 corresponding to the functional holes 113a, re-injecting electrolyte during a subsequent electrolyte re-injection process, and then sealing by a sealing process, can prevent the aluminum sheet 113 from being oxidized due to contact between the electrolyte and the functional holes 113a, or can prevent current from being conducted between the electrode assembly 120 and the aluminum sheet 113 through the functional holes 113a. For example, the coating portion 113b may contain silicon, but the material of the coating portion 113b is not limited to this.
[0031] like Figure 4 and Figure 6 As shown, in the re-injection process, additional electrolyte is injected into the pouch 110 through the functional orifice 113a. During the re-injection process, the portion of the polymer layers 111 and 116 covering the functional orifice 113a can be opened using tool P.
[0032] In one embodiment, during the re-injection process, additional electrolyte is injected through the functional pore 113a by piercing a portion of the polymer layers 111 and 116 that covers the functional pore 113a.
[0033] In another embodiment, during the re-injection process, additional electrolyte is injected through the functional pore 113a by passing an injection needle through a portion of the polymer layers 111 and 116 that covers the functional pore 113a.
[0034] Polymer layers 111 and 116 may include a first polymer layer 116 and a second polymer layer 111. The first polymer layer 116, the aluminum sheet 113, and the second polymer layer 111 are stacked sequentially from the inside out in a flexible package 110 housing the electrode assembly 120. The first polymer layer 116 and the second polymer layer 111 may be formed on both surfaces of the aluminum sheet 113 and cover the functional holes 113a formed in the aluminum sheet 113. The first polymer layer 116 and the second polymer layer 111 may each comprise a polymer material. Therefore, the first polymer layer 116 and the second polymer layer 111 covering the functional holes 113a may each comprise a polymer material permeable to gases such as CO and CO2, thereby allowing internal gases to escape and preventing electrolyte leakage through the functional holes 113a.
[0035] In the re-injection process, the electrolyte can be injected into the flexible package 110 through the functional hole 113a by opening the portion covering the functional hole 113a of the first polymer layer 116 and the second polymer layer 111. In the flexible package 110, a nylon layer 112 can be further laminated between the aluminum sheet 113 and the second polymer layer 111. In the re-injection process, the electrolyte can be injected into the flexible package 110 through the functional hole 113a by opening the portion covering the functional hole 113a of the first polymer layer 116, the nylon layer 112, and the second polymer layer 111.
[0036] In one embodiment, the first polymer layer 116 may be made of polypropylene (PP) material, and the second polymer layer 111 may be made of polyethylene terephthalate (PET) material.
[0037] In another embodiment, in the first polymer layer 116, the inner layer housing the electrode assembly 120 may be made of polypropylene (PP), while the outer layer facing the aluminum sheet 113 may be made of polyphthalamide (PPA). The second polymer layer 111 may be made of polyethylene terephthalate (PET).
[0038] like Figure 4 and Figure 7 As shown, in the sealing process, the functional hole 113a can be sealed after the re-injection process.
[0039] In the sealing process, the functional hole 113a can be sealed by sealing the opening in the second polymer layer 111 that corresponds to the functional hole 113a. Alternatively, the functional hole 113a can be sealed by filling the opening in the second polymer layer 111 with a sealing material R.
[0040] In one embodiment, during the sealing process, resin material R can be used to seal the opening portion in the second polymer layer 111.
[0041] In another embodiment, during the sealing process, the same material as the second polymer layer 111 can be used to seal the opening portion of the second polymer layer 111.
[0042] Therefore, the opening portion in the second polymer layer 111 is sealed with the same material as the second polymer layer 111. The material of the second polymer layer 111 includes a polymer material that allows CO and CO2 gases to pass through, so that even if the injected portion is sealed by a sealing process after the electrolyte is re-injected, the internal gas can still be discharged, and the electrolyte can be prevented from leaking through the functional hole 113a.
[0043] Secondary batteries capable of being refilled with electrolyte
[0044] In the following, a secondary battery capable of refilling electrolyte according to an embodiment of the present invention will be described.
[0045] like Figures 1 to 4 As shown, a rechargeable secondary battery 100 capable of electrolyte refilling according to an embodiment of the present invention includes an electrode assembly 120 assembled by alternating stacking of electrodes and a separator, and a soft pack 110 housing the electrode assembly 120. The soft pack 110 includes an aluminum sheet 113 and polymer layers 111 and 116 laminated with the aluminum sheet 113. Functional pores 113a are formed in the aluminum sheet 113.
[0046] The rechargeable secondary battery 100 according to an embodiment of the present invention is a secondary battery 100 that applies the electrolyte injectable method according to the above embodiment. Therefore, the same content as in the above embodiment will be omitted or briefly described, and the differences of this embodiment will be focused on.
[0047] More specifically, in the rechargeable secondary battery 100 according to an embodiment of the present invention, the electrode assembly 120 is a rechargeable power element and is assembled by alternating stacking of electrodes and separators.
[0048] Electrodes may include positive and negative electrodes, and positive electrodes, diaphragms, and negative electrodes may be arranged alternately.
[0049] Furthermore, the electrode assembly 120 may further include electrode leads 130 connected to the electrode ends. The electrode assembly 120 can be electrically connected to an external device via the electrode leads 130.
[0050] The soft package 110 can accommodate the electrode assembly 120, and a receiving portion for accommodating the electrode assembly 120 can be formed in the soft package 110.
[0051] In addition, the flexible package 110 may include an aluminum sheet 113 and polymer layers 111 and 116 laminated with the aluminum sheet 113.
[0052] Aluminum sheet 113 can be formed into aluminum sheet layers.
[0053] Functional hole 113a can be formed in aluminum sheet 113. Functional hole 113a can be formed on aluminum sheet 113, and its size is approximately 1 to 9 mm.
[0054] Functional aperture 113a may be formed to penetrate aluminum sheet 113 relative to the stacking direction of aluminum sheet 113 and polymer layers 111 and 116.
[0055] Functional hole 113a may be formed between electrode assembly 120 in soft package 110 and outer peripheral surface of soft package 110.
[0056] Additionally, a functional hole 113a can be formed on the side of the aluminum sheet 130 where the electrode lead 130 is located.
[0057] Polymer layers 111 and 116 may include a first polymer layer 116 and a second polymer layer 111. The first polymer layer 116 and the second polymer layer 111 may be formed on both surfaces of the aluminum sheet 113 and cover the functional holes 113a formed in the aluminum sheet 113. The first polymer layer 116 and the second polymer layer 111 may each comprise a polymer material. Therefore, the first polymer layer 116 and the second polymer layer 111 covering the functional holes 113a may each comprise a polymer material permeable to gases such as CO and CO2, thereby allowing internal gases to escape and preventing electrolyte leakage through the functional holes 113a.
[0058] like Figure 4 and Figure 5 As shown, the coating portion 113b can be disposed on the inner circumferential surface of the functional hole 113a in the aluminum sheet 113.
[0059] The coating portion 113b can be used to cover the entire inner circumferential surface of the functional hole 113a in the aluminum sheet 113. The coating portion 113b can contain an insulating and chemically resistant material. Therefore, by forming holes in the portions of polymer layers 111 and 116 corresponding to the functional hole 113a, re-injecting electrolyte, and then sealing, the aluminum sheet 113 can be prevented from being oxidized due to contact between the electrolyte and the functional hole 113a, or current can be prevented from being conducted between the electrode assembly 120 and the aluminum sheet 113 through the functional hole 113a. That is, the coating portion 113b is formed along the inner circumferential surface of the functional hole 113a, thereby preventing direct contact between the electrolyte and the aluminum sheet 113 when the electrolyte enters the functional hole 113a in the aluminum sheet 113 through the pore portion of the first polymer layer 116 after the pore portion of the first polymer layer 116 is formed. Then, the pore portion of the second polymer layer 111 is sealed after re-injection of electrolyte. Furthermore, the coating portion 113b is formed along the inner peripheral surface of the functional hole 113a, thereby preventing the electrode assembly 120 from directly contacting the aluminum sheet 113 through the holes in the first polymer layer 116.
[0060] For example, the coating portion 113b may contain silicon, but the material of the coating portion 113b of the present invention is not limited thereto.
[0061] Furthermore, the first polymer layer 116, the aluminum sheet 113, and the second polymer layer 111 can be stacked from the inside out in the flexible package 110 housing the motor assembly 120. In the flexible package 110, the first polymer layer 116, the aluminum sheet 113, and the second polymer layer 111 can be stacked and adhered, with each layer having a thickness of approximately 10 to 90 μm. Furthermore, in the flexible package 110, a nylon layer 112 can be further laminated between the aluminum sheet 113 and the second polymer layer 111. The nylon layer 112 is made of nylon material, allowing gas to permeate through it. Corresponding pores can be formed in the nylon layer 112 when the portions of the first polymer layer 116 and the second polymer layer 111 corresponding to the functional pores 113a in the aluminum sheet 113 form pores for electrolyte re-injection.
[0062] The second polymer layer 111 can be made of polyethylene terephthalate (PET) material.
[0063] In one embodiment, the first polymer layer 116 may be made of polypropylene (PP) material.
[0064] In another embodiment, in the first polymer layer 116, the inner layer housing the electrode assembly 120 may be made of polypropylene (PP) material, while the outer layer facing the aluminum sheet 113 may be made of polyphthalamide (PPA) material.
[0065] like Figure 3As shown, the sealing portion S can be formed on the outer peripheral surface of the flexible package 110 to seal the interior of the flexible package 110. The sealing portion S can be formed by heat-welding the outer peripheral surface of the flexible package 110 in a third or fourth direction.
[0066] Although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto, and those skilled in the art can implement the present invention in various ways within the scope of the technical concept of the present invention.
[0067] Furthermore, the scope of this invention may be defined by the appended claims.
[0068] [Explanation of reference numerals in the attached figures] 100: Secondary battery
[0069] 110: Soft Pack
[0070] 111: Second polymer layer; 112: Nylon layer
[0071] 113: Aluminum sheet
[0072] 113a: Functional hole
[0073] 113b: Coating section
[0074] 116: First polymer layer; 120: Electrode assembly; 130: Electrode lead.
Claims
1. A method for reinjecting an electrolyte into a secondary battery, wherein an electrode assembly and an electrolyte are housed in a pouch, the pouch comprising an aluminum sheet having functional pores and a polymer layer laminated on the aluminum sheet covering the functional pores, the polymer layer not filling the functional pores to leave the functional pores hollow prior to reinjection of the electrolyte, the method comprising: In the re-injection process, additional electrolyte is injected into the pouch through the functional pores by opening the portion of the polymer layer that covers them; as well as The sealing process, following the re-injection process, seals the functional pores by sealing the opened portions of the polymer layer that correspond to the functional pores.
2. The method according to claim 1, wherein, In the re-injection process, the additional electrolyte is injected through the functional pores by piercing the portion of the polymer layer that covers the functional pores.
3. The method according to claim 1, wherein, In the re-injection process, the additional electrolyte is injected through the functional pores by inserting an injection needle into the portion of the polymer layer that covers the functional pores.
4. The method according to claim 1, wherein, The polymer layer includes a first polymer layer and a second polymer layer. The first polymer layer, the aluminum sheet, and the second polymer layer are stacked from the inside out in the soft package housing the electrode assembly, and In the re-injection process, the electrolyte is injected into the pouch through the functional pores by opening the portions of the first polymer layer and the second polymer layer that cover the functional pores.
5. The method according to claim 4, wherein, In the sealing process, the functional hole is sealed by sealing the opening portion in the second polymer layer that corresponds to the functional hole.
6. The method according to claim 5, wherein, In the sealing process, a resin material is used to seal the opening portion of the second polymer layer.
7. The method according to claim 5, wherein, In the sealing process, the opening portion of the second polymer layer is sealed using the same material as the second polymer layer.
8. The method according to claim 4, wherein, The first polymer layer is made of polypropylene (PP) material, and the second polymer layer is made of polyethylene terephthalate (PET) material.
9. The method according to claim 4, wherein, The inner layer of the first polymer layer housing the electrode assembly is made of polypropylene (PP), and the outer layer of the first polymer layer facing the aluminum sheet is made of polyphthalamide (PPA). The second polymer layer is made of polyethylene terephthalate (PET) material.
10. The method according to claim 1, wherein, A coating portion is formed on the inner circumferential surface of the functional hole on the aluminum sheet.
11. The method according to claim 10, wherein, The coating portion contains insulating and chemically resistant materials.
12. A secondary battery capable of refilling with electrolyte, the secondary battery comprising: Electrode assembly in which electrodes and diaphragms are alternately stacked and bonded together; as well as A flexible package, wherein the electrode assembly is housed within the flexible package. The flexible package comprises an aluminum sheet and a polymer layer. Functional pores are formed in the aluminum sheet, and the polymer layer is stacked on top of the aluminum sheet and covers the functional pores. The polymer layer does not fill the functional pores, leaving the functional pores hollow before electrolyte re-injection, and A coating portion is provided on the inner circumferential surface of the functional hole in the aluminum sheet.
13. The secondary battery according to claim 12, wherein, The coating is applied to cover the entire inner circumferential surface of the functional holes in the aluminum sheet.
14. The secondary battery according to claim 12, wherein, The coating portion contains insulating and chemically resistant materials.
15. The secondary battery according to claim 12, wherein, The coating portion contains silicon.
16. The secondary battery according to claim 12, wherein, The functional hole penetrates the aluminum sheet relative to the stacking direction of the aluminum sheet and the polymer layer.
17. The secondary battery according to claim 12, wherein, The polymer layer includes a first polymer layer and a second polymer layer. The first polymer layer, the aluminum sheet, and the second polymer layer are stacked from the inside out in a soft package that houses the electrode assembly.
18. The secondary battery according to claim 17, wherein, The first polymer layer is made of polypropylene (PP) material, and the second polymer layer is made of polyethylene terephthalate (PET) material.
19. The secondary battery according to claim 17, wherein, The inner layer of the first polymer layer housing the electrode assembly is made of polypropylene (PP), and the outer layer of the first polymer layer facing the aluminum sheet is made of polyphthalamide (PPA). The second polymer layer is made of polyethylene terephthalate (PET) material.
20. The secondary battery according to claim 18, wherein, The functional hole is formed between the electrode assembly and the outer peripheral surface of the flexible package.