Battery convenient to recycle

Abstract

The utility model discloses a battery convenient to recycle, which comprises a functional current collector, the functional current collector comprises a macromolecule base membrane, an upper metal layer arranged on the upper side surface of the macromolecule base membrane, and a lower metal layer arranged on the lower side surface of the macromolecule base membrane; the edge of the functional current collector is provided with a connecting point, the polymer base film is fixedly connected with the upper metal layer and the lower metal layer at the connecting point, and the polymer base film, the upper metal layer and the lower metal layer are in a mutually independent state at other parts except the connecting point. And the mutually independent state is that the parts can be attached and contacted but are not mutually fixed. According to the utility model, metal materials and high polymer materials on the functional current collector can be conveniently recycled, and the cost is saved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a battery technical field, concretely relates to a battery convenient for recycling. BACKGROUND

[0002] With the rapid rise of new energy industry, the application scope of lithium ion electron is wider and wider, and the current collector is an indispensable active material carrier of lithium ion battery, which plays a crucial role in safety and electrical performance; the main role of the current collector is to carry electrode active material, collect and output the current generated by the active material, and input the electrode current to the active material; the current collector requires high purity, high conductivity, good chemical and electrochemical stability, high mechanical strength, and good combination with electrode active material.

[0003] Because the traditional current collector accounts for a large proportion in cost, and has greater safety hazards in the needling experiment, therefore, selecting the functional current collector (multi-layer current collector) can effectively reduce the raw material cost and improve the battery safety performance. The high molecular substrate layer in the middle of the functional current collector has good insulation performance and flame retardant performance, and the surface metal conductive layer is thin, which can be fused after short circuit, and can effectively improve the safety of battery use. Although the existing functional current collector has improved safety performance, recycling is more complex, the high molecular substrate layer in the middle needs to be separated from the surface metal conductive layer, and the recycling rate is low. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a battery convenient for recycling to solve the above problems, make the used material more easily recycled, save cost, and meet the requirements of environmental protection and sustainable development.

[0005] To achieve the above purpose, the utility model provides a technical scheme:

[0006] A battery convenient for recycling, comprising a functional current collector, wherein the functional current collector comprises a high molecular base film, an upper metal layer arranged on the upper side of the high molecular base film, and a lower metal layer arranged on the lower side of the high molecular base film.

[0007] The functional current collector is provided with a connecting point at the edge, the high molecular base film is fixedly connected with the upper metal layer and the lower metal layer at the connecting point, the high molecular base film and the upper metal layer and the lower metal layer are in a mutually independent state at other parts outside the connecting point, and the mutually independent state is that the high molecular base film and the upper metal layer and the lower metal layer can be attached and contacted but are not fixed to each other.

[0008] To optimize the above technical scheme, the specific measures taken also include:

[0009] The fixed connection between the high molecular base film and the upper metal layer and the lower metal layer at the connecting point is welding or riveting.

[0010] The connecting points are arranged within 8mm from the edge of the functional fluid.

[0011] The connecting points are arranged on at least two opposite edges of the functional fluid.

[0012] Further, the connecting points are arranged on all edges of the functional fluid.

[0013] The connecting points are arranged continuously to form a connecting band along the edge of the functional fluid, or are arranged at intervals to form discrete connecting points along the edge of the functional fluid.

[0014] Further, the welding is formed by laser or ultrasonic, and the riveting is formed by roll welding.

[0015] The functional fluid comprises a recycling area and a scrap area, the recycling area and the scrap area are separated parts formed by cutting along a cutting line arranged on the functional fluid, the part within the cutting line is the recycling area, and the part outside the cutting line is the scrap area; the cutting line is arranged on the inner side of the connecting points.

[0016] Further, the high-molecular base film and the upper and lower metal layers are in a state of mutual independence at other parts outside the connecting points before the functional fluid is recycled.

[0017] As an optional solution, the functional fluid is composed of an upper metal foil, a high-molecular base film and a lower metal foil which are laminated, and the upper metal foil, the high-molecular base film and the lower metal foil are fixedly connected at the connecting points on the edges.

[0018] As an optional solution, the functional fluid is composed of a high-molecular base film and upper and lower metal preparation layers arranged on both sides of the high-molecular base film, and the high-molecular base film and the metal preparation layers are fixedly connected at the connecting points on the edges, and the high-molecular base film and the metal preparation layers can be separated under the erosion of electrolyte to form a state of mutual independence except the connecting points.

[0019] Compared with the prior art, the utility model has the beneficial effects that:

[0020] The high polymer base film of the function current collector of the battery convenient to recycle is in the state of being independent of each other at other parts except the connecting points of the upper metal layer and the lower metal layer, can be attached and contacted but not fixed to each other, after the edge is cut during recycling, the metal layer and the high polymer base film on the inside can be easily separated, the recycling rate of the material and the recycling processing efficiency are improved, the cost is saved, the requirement of sustainable development is met, meanwhile, the connecting points arranged at the edge of the function current collector are used for fixing and connecting the high polymer base film and the upper metal layer and the lower metal layer through the connecting points, the positional relationship between the high polymer base film and the upper metal layer and the lower metal layer is stable during application of the function current collector, the risk of positive and negative electrode short circuit of the battery during application is avoided, and the cycle stability of the battery is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The utility model discloses a function current collector in the battery.

[0022] Figure 2 The utility model discloses a function current collector in the battery.

[0023] Figure 3 The utility model discloses a function current collector in the battery.

[0024] In the drawing: 1 - upper metal layer, 2 - high polymer base film, 3 - lower metal layer, 4 - connecting point, 5 - scattered connecting point, 6 - connecting band, 7 - cutting line. DETAILED DESCRIPTION

[0025] The above content of the utility model will be further explained in the form of embodiment, but this should not be understood as the range of the above subject matter of the utility model is limited to the following embodiment, and the technology realized based on the above content of the utility model belongs to the range of the utility model.

[0026] In the description of the utility model, it also needs to be explained that:

[0027] The orientation or positional relationship in it is the relationship shown in the drawing, is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or component must have a particular orientation, is constructed and operated in a particular orientation, therefore can not be understood as the limitation of the utility model.

[0028] The utility model provides a kind of battery convenient to recycle, including function current collector, function current collector includes high polymer base film 2 and is set on the upper side of high polymer base film 2 upper metal layer 1, lower metal layer 3 is set on the lower side of high polymer base film 2;

[0029] As Figure 1As shown, the functional current collector has connection points at the edge. The polymer base film 2 is fixedly connected to the upper metal layer 1 and the lower metal layer 3 at connection point 4. The polymer base film 2 and the upper metal layer 1 and the lower metal layer 3 are in an independent state at other parts outside the connection point. The independent state means that they can be in contact but are not fixed to each other.

[0030] The connection point is preferably located within 8 mm of the edge of the functional current collector, but other locations can be selected depending on the size of the functional current collector and the need for recycling.

[0031] In some implementations, such as Figure 2 As shown, the connection points are spaced-apart, dispersed connection points 5 forming along the edge of the functional current collector; in other embodiments, such as Figure 3 As shown, the connection points are continuously arranged connecting strips 6 forming along the edge of the functional current collector.

[0032] In some embodiments, connection points are provided at least on two opposite edges of the functional current collector. In a preferred embodiment, connection points are provided on all four edges of the functional current collector.

[0033] The functional current collector includes a recycling area and a scrapping area. The recycling area and the scrapping area are separate parts formed by cutting along the cutting line 7 set on the functional current collector. The part inside the cutting line 7 is the recycling area, and the part outside the cutting line 7 is the scrapping area. The cutting line 7 is set along the inside of the connection point.

[0034] The polymer base film 2 and the upper metal layer 1 and the lower metal layer 3 are in an independent state at other parts except for the connection point. They can exist at any stage before the functional current collector is recycled. That is, it can be easily cut and recycled, removing the waste area containing the connection point outside the cutting line 7, leaving the recycling area inside the cutting line 7. Since the polymer base film 2 and the upper metal layer 1 and the lower metal layer 3 in the recycling area are in an independent state, they can be easily separated, improving the recycling rate and recycling processing efficiency of metal materials and polymer materials.

[0035] The metal layer and polymer base membrane 2 separated in the recycling area are cleaned with chemical reagents to remove residual active substances, classified, and can be reused.

[0036] The connection point set at the edge of the functional current collector in this invention can ensure the positional state of the polymer base film 2, the upper metal layer 1, and the lower metal layer 3 when the functional current collector is in use, so that its positional relationship is stable, avoiding the risk of short circuit between the positive and negative electrodes of the battery caused by structural instability when the functional current collector is in use, and ensuring the cycle stability of the battery.

[0037] The fixed connection between the polymer base film 2 and the upper metal layer 1 and the lower metal layer 3 at the connection point can optionally be achieved by welding or riveting.

[0038] In some embodiments, the welding is formed by laser or ultrasound.

[0039] In some embodiments, the riveting is formed by roll welding; the riveting is formed by the welding teeth of roll welding, which is to make the metal layer of two sides and the polymer base film 2 in the concave formed by the welding teeth to produce a tight connection; as a reference, the welding tooth depth can be 30-80 μm.

[0040] Preferably, after the riveting by the welding teeth of roll welding, the edge riveting part is rolled and pressed by a constant roll gap, so that the surface of the functional current collector is overall flat.

[0041] In some embodiments, the functional current collector is composed of an upper metal foil, a polymer base film 2, and a lower metal foil, which are attached together, the upper metal foil serves as the upper metal layer 1, the lower metal foil serves as the lower metal layer 3, and the upper metal foil, the polymer base film 2, and the lower metal foil are fixedly connected at the edge connection points.

[0042] In other embodiments, the functional current collector is composed of a polymer base film 2 and metal preparation layers on the upper and lower sides thereof, the upper metal preparation layer serves as the upper metal layer 1, the lower metal preparation layer serves as the lower metal layer 3, and the polymer base film 2 and the metal preparation layers are fixedly connected at the edge connection points, and the polymer base film 2 and the metal preparation layers on the upper and lower sides thereof can be separated under the erosion of the electrolyte to form a mutually independent state except for the connection points.

[0043] The material of the metal layer of the present application can be selected from copper or aluminum.

[0044] The electrolyte of the present application can be selected from at least one or more mixed substances of ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl carbonate, methyl ethyl carbonate, lithium hexafluorophosphate, phosphorus pentafluoride, and hydrofluoric acid.

[0045] The polymer base film 2 of the present application can be selected from at least one of polypropylene, polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyimide, polypropylene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, polyphenylene sulfide, polyphenyl ether, polystyrene, and polyamide.

[0046] The thickness of the polymer base film 2 can be 2 μm to 12 μm as a reference; the thickness of the metal layer can be 0.5 to 2 μm as a reference.

[0047] The technical solutions of the present application are further described in detail below in combination with specific embodiments:

[0048] Example 1

[0049] The functional current collector is composed of an upper metal foil, a polymer base film 2, and a lower metal foil which are attached together; the polymer base film 2 is a PET film with a thickness of 5 μm; the upper and lower metal foils are copper foils with a thickness of 1 μm.

[0050] The upper metal foil, the polymer base film 2, and the lower metal foil are riveted at the connecting points at the edges 5 mm away by the welding teeth of the roll welding; the continuous riveting of the welding teeth makes the connecting points present as a continuous connecting band 6 formed along the edges of the functional current collector; after riveting, the edges of the riveting are rolled and pressed by a constant roll gap to make them flat.

[0051] When the functional current collector is recycled, the inside of the connecting band 6 is cut, and the part outside the cutting line 7 containing the connecting points is removed, and the material inside is recycled and reused.

[0052] Example 2

[0053] The functional current collector is composed of a polymer base film 2 and metal preparation layers on the upper and lower sides thereof; the polymer base film 2 is a PVC film with a thickness of 6 μm, and a low-molecular-weight PVDF adhesive layer which is soluble in electrolyte is coated on the surface of the polymer base film 2, such as the PVDF adhesive in the Aromat series; The molecular weight of the lithium battery adhesive grade PVDF is generally controlled below 100,000 Da, such adhesive can be easily dissolved in electrolyte and does not affect the cycle performance of the battery;

[0054] The polymer base film 2 and the metal preparation layers are connected and fixed at the connecting points at the edges by laser spot welding, and laser spot welding is performed along the edges 4 mm away from the functional current collector, forming dispersed connecting points 5 along the edges of the functional current collector; after the functional current collector is assembled for use in a battery, the polymer base film 2 and the metal preparation layers on the upper and lower sides thereof gradually separate under the erosion of electrolyte, forming a state of mutual independence except for the connecting points.

[0055] When the functional current collector is recycled, the inside of the connecting points is cut, and the part outside the cutting line 7 containing the connecting points is removed, and the material inside is recycled and reused.

[0056] Example 3

[0057] A battery:

[0058] (1) Preparation of the positive and negative functional current collectors:

[0059] The functional current collectors are prepared by the method of Example 2, wherein the positive functional current collector adopts an aluminum metal layer, and the preparation method is evaporation boat vacuum evaporation, and the thickness of the aluminum metal layer is 0.8 μm; the negative functional current collector adopts a copper metal layer, and the preparation method is magnetic control sputtering + water electroplating (first form a copper layer by magnetic control sputtering, and then thicken the copper layer by water electroplating), and the thickness of the copper metal layer is 0.8 μm;

[0060] (2) Preparation of the pole piece:

[0061] The positive pole piece is prepared by coating a positive pole material layer on a positive pole functional current collector, wherein the positive pole active material is lithium nickel cobalt manganese oxide (LiNi x Co γ Mn 1-x-γ O2, NCM); and the negative pole piece is prepared by coating a negative pole material layer on a negative pole functional current collector, wherein the negative pole active material is irregular carbon powder;

[0062] (3) Selection of the separator:

[0063] The polyethylene separator coated with aluminum oxide ceramic is used as the separator for assembling the battery;

[0064] (4) Preparation of the electrolyte:

[0065] Propylene carbonate, ethylene carbonate and methyl ethyl carbonate are taken, and the above materials are fully mixed according to a mass ratio of 1:1:1 to obtain a carbonate solvent; LiPF6 is added to the above carbonate solvent to prepare a carbonate solution of 1 mol·L -1 LiPF6, and the carbonate solution is used as the electrolyte of the lithium ion battery;

[0066] (5) Assembly of the lithium ion battery:

[0067] The above prepared positive pole piece, separator and negative pole piece are stacked in sequence to prepare a bare battery core; the bare battery core is placed in a lithium battery outer packaging shell, electrolyte is injected after drying, and the lithium ion battery is obtained through processes such as vacuum packaging, standing, formation, shaping and the like;

[0068] After the battery is used and before it is prepared for scrap recycling, the polymer base film 2 and the metal layer of the functional current collector have been separated, and the polymer base film 2 and the metal layer can be conveniently recycled. After the polymer base film 2 and the metal layer are separated, they are cleaned by chemical reagents and classified, and can be reused.

[0069] The above description is only a preferred embodiment of the present application, and does not limit the present application in any form. Any skilled person in the art, without departing from the technical solution of the present application, according to the technical essence of the present application, any simple modification, equivalent replacement and improvement of the above embodiment, all still belong to the protection scope of the technical solution of the present application.

Claims

1. A battery facilitating recycling, characterized by: The functional current collector includes a polymer base film and an upper metal layer arranged on the upper side of the polymer base film and a lower metal layer arranged on the lower side of the polymer base film. The functional current collector is provided with a connecting point at the edge, the polymer base film, the upper metal layer and the lower metal layer are fixedly connected at the connecting point, the polymer base film, the upper metal layer and the lower metal layer are in a mutually independent state at other parts outside the connecting point, and the mutually independent state is that the polymer base film, the upper metal layer and the lower metal layer can be attached to each other but are not fixed to each other.

2. The battery of claim 1, wherein: The fixed connection between the polymer base film, the upper metal layer and the lower metal layer at the connecting point is welding or riveting.

3. The battery of claim 1, wherein: The connecting point is arranged within 8 mm of the edge of the functional current collector.

4. The battery of claim 1, wherein: The connecting point is arranged at at least two opposite edges of the functional current collector.

5. The battery of claim 4, wherein: The connecting point is arranged at all four edges of the functional current collector.

6. The battery of claim 1, wherein: The connecting point is a continuous connecting band arranged along the edge of the functional current collector, or the connecting point is a dispersed connecting point arranged along the edge of the functional current collector.

7. The battery of claim 2, wherein: The welding is formed by laser or ultrasonic, and the riveting is formed by roll welding.

8. The battery of claim 1, wherein: The functional current collector includes a recycling area and a scrap area, the recycling area and the scrap area are separated parts formed by cutting along a cutting line arranged on the functional current collector, the part inside the cutting line is the recycling area, and the part outside the cutting line is the scrap area; and the cutting line is arranged inside the connecting point.

9. The battery of claim 1, wherein: The mutually independent state of the polymer base film, the upper metal layer and the lower metal layer at other parts outside the connecting point exists at any stage before the functional current collector is recycled.

10. The battery of claim 9, wherein: The functional current collector is composed of an upper metal foil, a polymer base film and a lower metal foil which are attached together, and the upper metal foil, the polymer base film and the lower metal foil are fixedly connected at the connecting point at the edge.

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