Ultrathin lithium-manganese soft package battery and preparation method thereof

Abstract

The invention discloses an ultrathin lithium-manganese soft package battery and a preparation method thereof, and relates to the technical field of ultrathin lithium-manganese soft package batteries, the ultrathin lithium-manganese soft package battery comprises a diaphragm-positive electrode combination body, the diaphragm-positive electrode combination body comprises a positive electrode and a diaphragm which are bonded through hot pressing, and the diaphragm-positive electrode combination body is folded by taking the diaphragm as an inner layer to form a U-shaped structure; the negative electrode is connected with a negative electrode lug, the negative electrode is placed in the U-shaped diaphragm-positive electrode combination body, and the two surfaces of the negative electrode are attached to the diaphragm; the lower-layer aluminum-plastic film is connected with a positive tab, the diaphragm-positive electrode combination body is placed on the lower-layer aluminum-plastic film, and the bottom surface of the diaphragm-positive electrode combination body is attached to the positive tab; and the periphery of the upper-layer aluminum plastic film is correspondingly connected with the periphery of the lower-layer aluminum plastic film in a sealing manner. The upper-layer aluminum-plastic film and the lower-layer aluminum-plastic film do not need shell punching to form positioning pits, one-time sealing forming is achieved, the problem of repeated sealing positioning depending on shell edge punching does not need to be considered, and the problem of poor packaging caused by repeated sealing pressing on a roll core can be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ultra-thin lithium-manganese soft package battery, and particularly relates to an ultra-thin lithium-manganese soft package battery and a preparation method thereof. BACKGROUND

[0002] The ultra-thin lithium-manganese soft package battery is widely used in smart cards such as financial cards and logistics positioning cards due to its thin thickness (<0.5 mm). In a traditional lithium-manganese soft package battery process, an aluminum plastic film shell is punched, a current collector of a positive plate is welded with a positive tab to form a positive group, a negative electrode is pressure-connected with a negative tab to form a negative group, the positive group and the negative group are pasted or wound into a roll core, then the roll core is put into the shell, top sealed, liquid injected, one sealed, vacuum double sealed, pre-discharged and cut, folded and ironed to form a battery. The traditional process has a shallow punching depth, and cannot position the position of the positive plate. When the sealing is performed by using the depth of the pit to position, the battery is prone to inaccurate positioning, resulting in poor sealing.

[0003] A Chinese patent application with the application number 201910184650.9 discloses a primary lithium-manganese ultra-thin battery and a preparation method thereof. The patent content is that an aluminum plastic film shell is punched, then a positive tab is laser cleaned, the positive tab is welded, and the shell is sealed multiple times. The process is complex, the yield is low, and the process cannot be applied to batch supply.

[0004] Therefore, there is a need for an ultra-thin lithium-manganese soft package battery and a preparation method thereof without punching, which is stable in structure and convenient for batch production. SUMMARY

[0005] The present application aims to solve the problems in the background art, and provides an ultra-thin lithium-manganese soft package battery and a preparation method thereof without punching, which is stable in structure and convenient for batch production.

[0006] The technical scheme of the present application is as follows: an ultra-thin lithium-manganese soft package battery comprises: a diaphragm-positive electrode combination, the diaphragm-positive electrode combination comprising a hot-pressed and bonded positive electrode and a diaphragm, the diaphragm-positive electrode combination being folded in half with the diaphragm as the inner layer to form a U-shaped structure; a negative electrode, the negative electrode being connected with a negative tab, and the negative electrode being placed in the U-shaped diaphragm-positive electrode combination and being attached to the diaphragm on both sides; a lower aluminum plastic film, the lower aluminum plastic film being connected with a positive tab, and the diaphragm-positive electrode combination being placed on the lower aluminum plastic film and being attached to the positive tab on the bottom surface; an upper aluminum plastic film, the upper aluminum plastic film being arranged above the diaphragm-positive electrode combination and being sealed and connected with the lower aluminum plastic film around.

[0007] Preferably, the positive electrode comprises a current collector and positive electrode active material coated on one side of the current collector, the separator-positive electrode combination is formed by hot pressing and bonding the separator to the positive electrode active material on the positive electrode, and the separator-positive electrode combination is fully infiltrated with electrolyte.

[0008] Further, the positive electrode has a thickness of 60-120 microns, and the current collector is an aluminum foil with a thickness of 10-25 microns. The separator has a thickness of 10-20 microns, and the separator comprises a film base material and a PVDF coating arranged on both sides of the film base material. The negative electrode is a lithium strip with a thickness of 50-70 microns.

[0009] Preferably, the film base material is made of PP or PE, the positive electrode tab is made of stainless steel or nickel, and the negative electrode tab is made of nickel.

[0010] Preferably, the lower aluminum plastic film is provided with a top sealing edge, and when the separator-positive electrode combination is placed on the lower aluminum plastic film, the U-shaped opening of the separator-positive electrode combination faces the top sealing edge.

[0011] Further, one end of the negative electrode tab is provided with a first punched hole, and the end with the first punched hole is riveted to the negative electrode, and the other end of the negative electrode tab extends out of the negative electrode and is provided with a negative electrode tab adhesive connected to the inner surface of the top sealing edge.

[0012] Further, the positive electrode tab is provided with a positive electrode tab adhesive connected to the inner surface of the top sealing edge, and one end of the positive electrode tab extending into the lower aluminum plastic film is provided with a second punched hole for closely contacting the bottom surface of the separator-positive electrode combination.

[0013] Preferably, the upper aluminum plastic film and the lower aluminum plastic film are both in the original state of planar sheet film structure and are respectively attached to the upper and lower surfaces of the separator-positive electrode combination for vacuum sealing connection.

[0014] The application also provides a preparation method of the above ultra-thin lithium-manganese soft pack battery, comprising: A positive electrode with positive electrode active material on one side is used, the separator is attached to the positive electrode active material for hot pressing to obtain a separator-positive electrode combination, and electrolyte is added for standing; The negative electrode tab is riveted to the negative electrode, the negative electrode attached to the separator is placed at one end of the separator-positive electrode combination, and the other end of the separator-positive electrode combination is folded to form a U-shaped structure with the negative electrode clamped inside; The positive electrode tab is connected to the lower aluminum plastic film, the separator-positive electrode combination with the negative electrode clamped inside is placed on the lower aluminum plastic film with the bottom surface attached to the positive electrode tab, and the negative electrode tab is connected to the lower aluminum plastic film; The upper aluminum plastic film is placed above the separator-positive electrode combination, and the lower aluminum plastic film is vacuum sealed around the four sides, and then pre-discharge, battery punching and forming are sequentially performed to obtain the ultra-thin lithium-manganese soft pack battery product.

[0015] Preferably, the negative tab is riveted to the negative electrode, specifically comprising: The negative tab is riveted to the negative electrode, specifically comprising: The negative tab is riveted to the negative electrode, specifically comprising: The positive tab is connected to the lower layer of aluminum plastic film, specifically comprising: The positive tab is connected to the lower layer of aluminum plastic film, specifically comprising:

[0016] Further, when the separator-positive electrode combination with the negative electrode clamped is placed on the lower layer of aluminum plastic film with the positive tab, the U-shaped opening of the separator-positive electrode combination faces the top sealing edge; The negative tab is connected to the lower layer of aluminum plastic film, specifically comprising:

[0017] The thickness of the finished product of the ultra-thin lithium-manganese soft-pack battery is less than or equal to 0.5 mm.

[0018] The beneficial effects of the present application are: 1. The upper layer of aluminum plastic film and the lower layer of aluminum plastic film of the present application do not need to punch the shell to form a positioning pit, and one-time sealing forming is not needed to consider the problem of positioning by punching the shell edge multiple times, which can avoid the problem of poor packaging of the winding core caused by multiple sealing.

[0019] 2. The separator-positive electrode combination of the present application, in which the positive electrode and the separator are hot-pressed into a whole, can reduce the gap between the separator and the electrode sheet and reduce the interface impedance; the negative electrode sheet is clamped inside and folded to form a U-shaped structure, which has the advantages that the separator and the positive electrode sheet are hot-pressed and fixed, the position of the separator will not move after the battery post-process, and the positive electrode sheet will not be exposed outside the separator, avoiding the short circuit of the battery caused by the contact between the positive electrode sheet and the negative electrode sheet; the existing technology is a single-layer positive electrode sheet and a single-layer negative electrode sheet, and the contact area of the electrode sheet is small, and the U-shaped structure increases the contact area of the positive electrode sheet and the negative electrode sheet by 1 times, increasing the large current or low temperature power output of the battery.

[0020] 3. The present application adopts a positive tab punching structure, and the positive tab is directly connected to the lower layer of aluminum plastic film through the tab glue, and the punched end is in contact with the positive current collector, compared with the existing technology in which the positive tab is connected to the current collector or the current collector port is laser cleaned and then connected to the current collector, the present application does not need to reserve a welding position on the positive electrode sheet, fully utilizes the battery space, and improves the battery capacity.

[0021] 4. In the present application, the positive tab and the positive tab are connected by tight contact, and the edge of the through hole on the positive tab will form a micro burr structure during processing (such as stamping or laser cutting). These burrs can be embedded in the current collector layer on the surface of the positive tab, which is beneficial to increase the contact with the positive tab, and the positive current collector can be embedded in the through hole on the positive tab, which is beneficial to increase the contact between the two and improve the charge transfer efficiency.

[0022] 5. In the present application, the separator-positive combination adds electrolyte from the separator, so that the separator and the positive electrode are fully infiltrated. The prior art needs to reserve an air bag bag on the aluminum plastic film of the shell after sealing, then the injection needle is put into the air bag to inject liquid, and finally the air bag bag is cut off by vacuum two-sealing, which causes a large waste of aluminum plastic film. The shell of the present application does not need to reserve an air bag bag, and there is no waste of air bag bag of aluminum plastic film, saving material cost and process cost.

[0023] 6. In the present application, the negative tab is placed on the negative tab (lithium strip), and when riveting by pressure, the lithium strip can be embedded in the through hole of the negative tab, which is beneficial to increase the contact between the two and improve the charge transfer efficiency.

[0024] 7. The plane aluminum plastic film vacuum packaging process of the present application can shorten the production rhythm, and the no-pit design can reduce the packaging wrinkle rate of the aluminum plastic film and improve the utilization rate. The traditional process needs to go through top sealing→side sealing→liquid injection→tail sealing→vacuum two-sealing and other independent sealing processes. After each sealing, it needs to be transferred to the next station. The present application only needs to complete all sealing through vacuum one-sealing, which saves multiple sealing and is efficient and fast.

[0025] 8. In the present application, the tab with double-sided tab glue is used, which is convenient for the tab to quickly melt and seal with the upper and lower aluminum plastic films.

[0026] 9. In the present application, the process of heat pressing→folding→tab group embedding→one-time vacuum packaging realizes full-process online continuous operation, shortens the production rhythm, reduces the equipment floor space, and at the same time eliminates the quality risks such as tab group misplacement and shell deformation in the transfer process.

[0027] 10. The one-time lithium-manganese ultra-thin CP042039 soft package battery prepared in the present application has a capacity increased by 13% compared with the existing product, which greatly improves the battery capacity. This is because the traditional positive tab connection mode is to reserve an aluminum current collector on the positive tab, and then the reserved area is welded with the positive tab. The welding area wastes effective space (no active material and no power output), which leads to less battery capacity. In the present application, the positive tab does not need to reserve an aluminum current collector, and the same size space has a higher utilization rate. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 Negative tab structure plan view Figure 2 Negative tab structure plan view Figure 3 Negative tab structure plan view Figure 4 Negative tab structure plan view Figure 5 Positive tab-separator combination plan view Figure 6 Positive tab-separator combination plan view Figure 7 Negative tab on negative plan view Figure 8 Negative on positive-separator combination plan view Figure 9 Positive-separator combination folded into U shape plan view Figure 10 Positive-separator combination folded into U shape plan view Figure 11 Positive tab welded to lower layer of aluminum plastic film plan view Figure 12 Positive-separator combination with negative sandwiched between placed on lower layer of aluminum plastic film plan view Figure 13 Upper layer of aluminum plastic film plan view Figure 14 Finished product ultra-thin lithium manganese soft-pack battery schematic diagram

[0029] Wherein: 1-positive electrode 2-separator 3-negative electrode 4-lower layer of aluminum plastic film (4.1-top edge) 5-upper layer of aluminum plastic film 6-negative tab 7-first punched hole 8-positive tab 9-second punched hole 10-current collector 11-positive active material 12-positive-separator combination 3.1-negative tab adhesive 8.1-positive tab adhesive. DETAILED DESCRIPTION

[0030] Embodiments of the present application are described in detail below, in which like reference numerals refer to like elements or elements with similar functions throughout the description. The embodiments described below are exemplary, and are intended to explain the present application, and are not to be understood as limiting the present application.

[0031] In the description of the present application, it should be understood that the terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0032] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited. The devices not described in detail in the present application are commonly used devices in the art.

[0033] The following specific examples further illustrate the present application.

[0034] Example 1 As Figures 1-14 shown, the present embodiment provides an ultra-thin lithium manganese soft pack battery, which comprises a separator-positive electrode combination 12, a negative electrode 3, a lower layer of aluminum plastic film 4, and an upper layer of aluminum plastic film 5. The specific structure of the separator-positive electrode combination 12 includes a hot-pressed and bonded positive electrode 1 and a separator 2, as shown in Figure 5 The separator 2 and the positive electrode 1 are both long strips with consistent length direction, the edges of the separator 2 slightly exceed the positive electrode 1, the positive electrode 1 includes a current collector 10 and a positive electrode active material 11 coated on one side of the current collector 10, the separator 2 is bonded to the positive electrode active material 11 to form a separator-positive electrode combination 12, the separator-positive electrode combination 12 is fully soaked with electrolyte, and the separator-positive electrode combination 12 is folded in length direction to form a U-shaped structure with the separator 2 as the inner layer, and the length after folding is only half of the original length.

[0035] The negative electrode 3 is connected with a negative electrode tab 6, the negative electrode 3 is placed in the U-shaped separator-positive electrode combination 12 and adheres to the separator 2 on both sides, and the negative electrode tab 6 extends out of the U-shaped opening of the separator-positive electrode combination 12. In some preferred examples, as shown in Figures 1-2 the negative electrode tab 6 is provided with a negative electrode tab adhesive 6.1, the negative electrode tab adhesive 6.1 is clamped on both sides of the negative electrode tab 6, the tab adhesive is a thermoplastic plastic material in solid state at room temperature, and can realize the connection and installation of the tab after melting. In some preferred examples, one end (lower end) of the negative electrode tab 6 is provided with a first punching hole 7, as shown in Figure 1 Figure 7 ​As shown, the end (lower end) of the first punched hole 7 of the negative tab 6 is riveted to the negative electrode 3, and the first punched hole 7 can make the riveting of the negative tab 6 more compact. The negative tab rubber 6.1 is arranged on the end of the negative tab 6 extending out of the separator-positive electrode combination 12.

[0036] The lower layer of aluminum plastic film 4 is a rectangle with a size corresponding to the U-shaped separator-positive electrode combination 12, and the top sealing edge 4.1 is arranged on the lower layer of aluminum plastic film 4. The positive tab 8 is connected to the top sealing edge 4.1 of the lower layer of aluminum plastic film 4. In some preferred examples, as shown in FIG. 2, the positive tab 8 is connected to the top sealing edge 4.1 of the lower layer of aluminum plastic film 4. Figures 3-4 As shown, the positive tab 8 is provided with the positive tab rubber 8.1, and the positive tab rubber 8.1 is arranged on both sides of the positive tab 8. The tab rubber is a thermoplastic material in a solid state at room temperature, and can be connected and installed to the tab after being heated and melted. The positive tab rubber 8.1 is fused and welded with the inner surface of the top sealing edge 4.1, and the positive tab 8 is fixed to the lower layer of aluminum plastic film 4. In some preferred examples, the positive tab 8 is provided with the second punched hole 9 at the end (middle lower end) extending into the lower layer of aluminum plastic film 4, which is used to tightly contact the bottom surface of the separator-positive electrode combination 12. Figure 11 The outer layer of the separator-positive electrode combination 12 is the current collector 10, and the burrs generated during the processing of the second punched hole 9 are beneficial to increase the contact between the positive tab 8 and the current collector 10. At the same time, the current collector 10 can be embedded into the second punched hole 9, which is beneficial to increase the contact between the positive tab 8 and the current collector 10, and improve the charge transfer efficiency.

[0037] The U-shaped separator-positive electrode combination 12 is arranged on the lower layer of aluminum plastic film 4, and the U-shaped opening of the U-shaped separator-positive electrode combination 12 faces the top sealing edge 4.1. The negative tab rubber 6.1 is fused and welded with the inner surface of the top sealing edge 4.1, and the negative tab 6 is fixed to the lower layer of aluminum plastic film 4.

[0038] The upper layer of aluminum plastic film 5 corresponds to the lower layer of aluminum plastic film 4 in shape, and the upper layer of aluminum plastic film 5 is arranged above the separator-positive electrode combination 12 and is sealed and connected with the lower layer of aluminum plastic film 4 around.

[0039] In some preferred examples, the positive electrode 1 has a thickness of 60-120 μm (more preferably, the thickness is 85 μm), and the current collector 10 is an aluminum foil with a thickness of 10-25 μm. The positive tab 8 is a stainless steel tab or a nickel tab.

[0040] In some preferred examples, the separator 2 has a thickness of 10-20 μm, and the separator 2 includes a film base material and a PVDF (polyvinylidene fluoride) coating arranged on both sides of the film base material. The film base material is made of PP (polypropylene) or PE (polyethylene).

[0041] In some preferred examples, the negative electrode 3 is a lithium strip with a thickness of 50-70 μm (more preferably, the thickness is 50 μm). The negative tab 6 is a nickel tab.

[0042] In the present application, the lower layer of aluminum plastic film 4 and the upper layer of aluminum plastic film 5 are both in the original state of a flat sheet film structure, and neither needs to be punched to form a positioning pit. The existing ultra-thin soft package battery sealing machine can be used to realize one-time sealing and molding, which can avoid the problem of poor packaging of the punched shell multiple times pressed on the roll core, and improve the yield.

[0043] Example 2 The present application provides a preparation method of an ultra-thin lithium manganese soft package battery, comprising: The positive electrode 1 with a positive active material 11 on one side is used to bond the positive active material 11 and the diaphragm 2 by hot pressing to obtain a diaphragm-positive electrode combination 12. The hot pressing parameters are: temperature 70-100℃, pressure 0.2-0.5Mpa, time 2-3s, and electrolyte is added and left standing. The negative tab 6 with negative tab glue 6.1 on both sides of the negative tab 6 is used. The first punch hole 7 is opened at one end of the negative tab 6, and the end with the first punch hole 7 is riveted with the negative electrode 3. The negative electrode 3 is placed at one end of the diaphragm-positive electrode combination 12, and the other end of the diaphragm-positive electrode combination 12 is folded to form a U-shaped structure with the negative electrode 3 inside. The positive tab 8 with positive tab glue 8.1 on both sides of the positive tab 8 is used. The second punch hole 9 is opened at one end of the positive tab 8, and the end with the second punch hole 9 is inserted into the lower layer of aluminum plastic film 4. The positive tab glue 8.1 is fusion welded with the inner surface of the top sealing edge 4.1 on the lower layer of aluminum plastic film 4 to fix the positive tab 8. The diaphragm-positive electrode combination 12 with the negative electrode 3 is placed on the lower layer of aluminum plastic film 4, and the outer layer of the diaphragm-positive electrode combination 12 is the current collector 10. The bottom surface of the current collector 10 is bonded with the positive tab 8. The U-shaped opening of the diaphragm-positive electrode combination 12 faces the top sealing edge 4.1. The negative tab glue 6.1 is fusion welded with the inner surface of the top sealing edge 4.1 to fix the negative tab 6. The upper layer of aluminum plastic film 5 is covered on the diaphragm-positive electrode combination 12, and the lower layer of aluminum plastic film 4 is vacuum sealed around. The preparation method includes pre-discharge, battery punching and molding, and an ultra-thin lithium manganese soft package battery product is obtained.

[0044] When the negative tab glue 6.1 and the inner surface of the top sealing edge 4.1 are fusion welded, and the positive tab glue 8.1 and the inner surface of the top sealing edge 4.1 are fusion welded, the welding conditions are consistent: temperature 120-150℃, time 2-3s.

[0045] The preparation method of the present application is applied to CP042039 soft package battery, and the application of the present application to other types of batteries also has a guiding effect. Combined with the specific structure of Example 1, the preparation method of the ultra-thin lithium manganese soft package battery is as follows: The positive electrode 1 with positive active material 11 on one side can be purchased or prefabricated. It can be prefabricated according to the following process: use an aluminum foil with a thickness of 20μm and a width of 420mm as the current collector 10, and use a continuous coating process to coat one side of the current collector 10 with positive electrode slurry (common positive electrode slurry is made from raw materials including manganese dioxide, conductive agent and glue). Roll forming is used to form positive active material 11 on one side of the current collector 10, resulting in a whole roll of positive electrode material with a thickness of 85μm. The 420mm wide roll of positive electrode is slit into small rolls with a width of 25mm using a slitting machine. The small rolls of positive electrode with a width of 25mm are dried in an oven to remove water and punched with a mold to obtain a positive electrode sheet of a preset size, that is, the positive electrode 1 with positive active material 11 on one side.

[0046] S1: Preparation of the separator-positive electrode complex like Figures 5-6 As shown, the rolled-up separator 2 is bonded to the side of the positive electrode 1 containing the positive electrode active material 11 and then hot-pressed (heating temperature 70℃, pressure 0.35~0.5Mpa, heating time 3s) to obtain a separator-positive electrode composite 12. The separator 2 is then cut using a laser. After cutting, the size of the separator 2 is adapted to the positive electrode 1, with its dimensions slightly larger than those of the positive electrode 1. Electrolyte is added to the separator 2 in multiple batches and allowed to stand, allowing the electrolyte to be fully absorbed by the separator 2 and the positive electrode active material 11 of the positive electrode 1.

[0047] S2: Preparation of negative electrode assembly like Figures 1-2 As shown, a negative electrode tab 6 with built-in negative electrode adhesive 6.1 is used. The negative electrode adhesive 6.1 is sandwiched between the two sides of the negative electrode tab 6. The adhesive is a thermoplastic material that is solid at room temperature, and can be used to connect and fix the electrode tab after heating and melting. Figure 7 As shown, at one end of the negative electrode tab 6 ( Figure 7 The first punch 7 (Φ1.5mm) is made at the middle and lower end, and the end where the first punch 7 is located is riveted to the negative electrode 3 to obtain the negative electrode group. The setting of the first punch 7 can make the negative electrode tab 6 more tightly riveted. The negative electrode 3 is a lithium strip with a thickness of 50μm.

[0048] S3: Preparation of U-shaped structure like Figure 8 As shown, the negative electrode 3 is attached to the separator 2 and placed at one end of the separator-positive electrode adhesive 12. Figure 8 (Middle and upper end), the other end of the diaphragm-positive electrode adhesive 12 ( Figure 8 The lower middle section is folded 180° along a pre-set fold line to form a U-shaped structure that clamps the negative electrode 3 inside. The fold line is as follows: Figure 8 As shown by the horizontal dashed line, the axis of symmetry is perpendicular to the length direction. A gap of approximately 0.5mm is left between the fold line and the lower end of the negative electrode 3 to avoid squeezing the negative electrode 3 during the folding process, ensuring the flatness of the negative electrode 3. The separator-positive electrode adhesive 12 sandwiched inside the negative electrode 3 is as follows... Figures 9-10The core is formed.

[0049] S4: positive and negative assembly As Figures 3-4 shown, the positive lug 8 is provided with the positive lug rubber 8.1, the positive lug rubber 8.1 is provided on both sides of the positive lug 8, and the second punching hole 9 (Φ1.5mm) is provided at one end of the positive lug rubber 8.1, as Figure 11 shown, the end of the second punching hole 9 is pasted into the lower layer of aluminum plastic film 4 in a planar sheet shape, and the positive lug rubber 8.1 is fused and welded with the inner surface of the top sealing edge 4.1 of the lower layer of aluminum plastic film 4 by using a heat sealing machine, so that the positive lug 8 is fixedly connected to the top sealing edge 4.1, the width of the top sealing edge 4.1 is about 3-4mm, the fusion temperature is 120-150℃, and the time is 2s. Figure 11

[0050] As Figure 12 shown, the diaphragm-positive electrode adhesive body 12 clamping the negative electrode 3 is placed on the lower layer of aluminum plastic film 4, the U-shaped opening of the diaphragm-positive electrode adhesive body 12 faces the top sealing edge 4.1, and the negative lug rubber 6.1 is fused and welded with the inner surface of the top sealing edge 4.1 by using a heat sealing machine, so that the negative lug 6 is fixedly connected to the top sealing edge 4.1, and the fusion temperature is 120-150℃ and the time is 2s.

[0051] S5: product packaging The upper layer of aluminum plastic film 5 in a planar sheet shape is covered on the diaphragm-positive electrode adhesive body 12, aligned with the lower layer of aluminum plastic film 4 around, and then vacuum sealed to seal the four edges at one time, and the vacuum sealing parameters are: vacuum degree ≤-95kpa, temperature: 130-140℃, time: 3.5s. The pre-discharge, battery punching forming are sequentially carried out, and the ultra-thin lithium manganese soft package battery product is prepared, as Figure 13 shown. Figure 14

[0052] Performance test The size and battery performance of the primary lithium manganese ultra-thin CP042039 soft package battery prepared by the present application are tested, wherein the primary lithium manganese ultra-thin CP042039 soft package battery prepared by the present application is compared with a certain brand of battery in the market (prepared according to the traditional lithium manganese soft package battery process in the background art), and the results are shown in the following table 1.

[0053] Table 1 From the above table 1, it can be seen that the capacity of the primary lithium manganese ultra-thin CP042039 soft package battery prepared by the present application is increased by 13% compared with the certain brand in the market, and the unique structure and preparation method of the present application greatly improve the battery capacity.

[0054] ​​The above merely describes preferred embodiments of the present application, and is not intended to limit the present application in any form; any person skilled in the art can easily implement the present application according to the drawings and the above description; however, any person skilled in the art can make some changes, modifications and equivalent changes of the above disclosed technical contents without departing from the technical solution of the present application, and the equivalent embodiments of the present application are still within the protection scope of the present application.

Claims

1. An ultra-thin lithium manganese pouch cell, characterized in that, The application relates to a lithium battery, which comprises the following parts: a diaphragm-positive electrode combination (12) comprising a hot-press-bonded positive electrode (1) and diaphragm (2), the diaphragm-positive electrode combination (12) being folded in a U-shaped structure with the diaphragm (2) as the inner layer; a negative electrode (3) with a negative electrode tab (6) connected thereto, the negative electrode (3) being placed in the U-shaped diaphragm-positive electrode combination (12) and being attached to the diaphragm (2) on both sides; a lower layer of aluminum plastic film (4) with a positive electrode tab (8) connected thereto, the diaphragm-positive electrode combination (12) being placed on the lower layer of aluminum plastic film (4) and being attached to the positive electrode tab (8) on the bottom; an upper layer of aluminum plastic film (5) being arranged above the diaphragm-positive electrode combination (12) and being sealedly connected with the lower layer of aluminum plastic film (4) around.

2. The ultra-thin lithium-manganese soft-pack battery of claim 1, wherein, The positive electrode (1) comprises a current collector (10) and positive electrode active material (11) arranged on one side of the current collector (10), the diaphragm-positive electrode combination (12) being formed by hot-press bonding of the diaphragm (2) and the positive electrode active material (11) on the positive electrode (1), and the diaphragm-positive electrode combination (12) being fully soaked with electrolyte.

3. The ultra-thin lithium-manganese soft-pack battery of claim 2, wherein, The thickness of the positive electrode (1) is 60-120 mu m, and the current collector (10) is an aluminum foil with a thickness of 10-25 mu m; The thickness of the diaphragm (2) is 10-20 mu m, and the diaphragm (2) comprises a film base material and PVDF coating arranged on both sides of the film base material; The negative electrode (3) is a lithium strip with a thickness of 50-70 mu m.

4. The ultra-thin lithium-manganese soft-pack battery of claim 1, wherein, The lower layer of aluminum plastic film (4) is provided with a top sealing edge (4.1), and when the diaphragm-positive electrode combination (12) is placed on the lower layer of aluminum plastic film (4), the U-shaped opening of the diaphragm-positive electrode combination (12) faces the top sealing edge (4.1).

5. The ultra-thin lithium-manganese soft-pack battery of claim 4, wherein, One end of the negative electrode tab (6) is provided with a first punching hole (7), and the end with the first punching hole (7) is riveted to the negative electrode (3), and the other end of the negative electrode tab (6) extends out of the negative electrode (3) and is provided with negative electrode tab rubber (6.1) connected with the inner surface of the top sealing edge (4.1).

6. The ultra-thin lithium-manganese soft-pack battery of claim 4, wherein, The positive electrode tab (8) is provided with positive electrode tab rubber (8.1) connected with the inner surface of the top sealing edge (4.1), and one end of the positive electrode tab (8) extending into the lower layer of aluminum plastic film (4) is provided with a second punching hole (9) for closely contacting the bottom surface of the diaphragm-positive electrode combination (12).

7. The ultra-thin lithium-manganese soft-pack battery of claim 1, wherein, The upper layer of aluminum plastic film (5) and the lower layer of aluminum plastic film (4) are both in the original state of planar sheet-shaped film structure and are vacuum-sealedly connected with the upper and lower surfaces of the diaphragm-positive electrode combination (12) respectively.

8. A method of manufacturing the ultra-thin lithium-manganese soft-pack battery according to any one of claims 1 to 7, characterized by, The application also discloses a preparation method of the lithium battery, which comprises the following steps: a positive electrode (1) with positive electrode active material (11) arranged on one side is adopted, the diaphragm (2) is attached to the positive electrode active material (11) to obtain a diaphragm-positive electrode combination (12) through hot pressing, and electrolyte is added and left to stand; a negative electrode tab (6) is riveted to a negative electrode (3), the negative electrode (3) is attached to the diaphragm (2) and is placed at one end of the diaphragm-positive electrode combination (12), and the other end of the diaphragm-positive electrode combination (12) is folded to form a U-shaped structure with the negative electrode (3) clamped inside. The positive tab (8) is connected with the lower layer of aluminum plastic film (4), the separator-positive adhesion body (12) with the negative electrode (3) sandwiched is placed on the lower layer of aluminum plastic film (4) and the bottom surface is attached to the positive tab (8), and the negative tab (6) is connected with the lower layer of aluminum plastic film (4); The upper layer of aluminum plastic film (5) is covered on the separator-positive adhesion body (12) and vacuum sealed with the lower layer of aluminum plastic film (4) around, and pre-discharge, battery cutting forming are sequentially carried out, and the ultra-thin lithium manganese soft package battery product is prepared. 9.The method of claim 8, wherein the soft pouch cell is a lithium-manganese battery having a thickness of 5 mm or less. The negative tab (6) is riveted on the negative electrode (3), specifically including: The negative tab (6) is provided with negative tab glue (6.1) on both sides, a first punching hole (7) is formed at one end of the negative tab (6), and the end with the first punching hole (7) is riveted with the negative electrode (3); The positive tab (8) is connected with the lower layer of aluminum plastic film (4), specifically including: The positive tab (8) is provided with positive tab glue (8.1) on both sides, a second punching hole (9) is formed at one end of the positive tab (8), and the end with the second punching hole (9) is inserted into the lower layer of aluminum plastic film (4), and the positive tab glue (8.1) is fusion welded with the inner surface of the top sealing edge (4.1) of the lower layer of aluminum plastic film (4) to fix the positive tab (8). 10.The method of claim 9, wherein the soft pouch cell is a lithium-manganese battery. When the separator-positive adhesion body (12) with the negative electrode (3) sandwiched is placed on the lower layer of aluminum plastic film (4) with the positive tab (8), the U-shaped opening of the separator-positive adhesion body (12) faces the top sealing edge (4.1). The negative tab (6) is connected with the lower layer of aluminum plastic film (4), specifically including: the negative tab glue (6.1) is fusion welded with the inner surface of the top sealing edge (4.1) to fix the negative tab (6).

Images