Lithium ion battery cell, manufacturing method and lithium ion battery

Abstract

The invention discloses a lithium ion battery cell, a manufacturing method and a lithium ion battery; it relates to the technical field of lithium ion battery manufacturing; the manufacturing method comprises the following steps: S1, preparation of a first metal film; S2, connection of a non-woven fabric, the end of the first metal film is compositely connected to the non-woven fabric by an adhesive, the width of the non-woven fabric is smaller than the width of the first metal film; S3, preparation of a pole piece, coating an active slurry on the first metal film and the overlapping part of the first metal film and the non-woven fabric, the active slurry is solidified to form an active material layer, thereby obtaining a pole piece; S4, preparation of a pole ear, coating a heat conductive layer on the surface of the non-woven fabric away from the first metal layer, and plating a second metal layer on the heat conductive layer, thereby obtaining a lithium ion battery cell; the invention has the beneficial effects of avoiding burrs at the connection between the pole ear and the pole piece, and preventing the burrs from piercing the diaphragm so that the positive electrode and the negative electrode are in direct contact and thus generating a short circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium ion battery manufacturing, and more specifically, to a lithium ion battery cell, a manufacturing method and a lithium ion battery. Background Art

[0002] As a green and environmentally friendly new energy, lithium-ion batteries have the advantages of good reliability, high safety, small size, and light weight. They have been widely used in digital products, electric vehicles, military products, etc. With the country's strong support for new energy, the development of lithium-ion batteries is in full swing, but the requirements for the service life, safety, and low cost of lithium-ion batteries are also getting higher and higher. At present, lithium-ion batteries are also developing in the direction of long life, high safety, high rate, and low cost.

[0003] However, with the development of lithium-ion batteries over time, many problems have arisen in the use of lithium-ion batteries, such as safety and energy density. As far as safety is concerned, one of the reasons is that the diaphragm is punctured by burrs at the connection between the pole ear and the pole piece, causing the positive and negative pole pieces to contact each other and short-circuit, causing the battery to heat up. The heat cannot be transferred, causing fires or even explosions. The current battery cells are made of pure metal, which also makes the battery too heavy, affecting the battery energy density. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a lithium ion battery cell, a manufacturing method and a lithium ion battery, which avoid burrs at the connection between the pole ear and the pole piece, and prevent the burrs from piercing the diaphragm so that the positive and negative electrodes are in direct contact and thus cause a short circuit.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a method for manufacturing a lithium-ion battery cell, the improvement of which is that the manufacturing method comprises the following steps:

[0006] S1, preparing a first metal film, using a vacuum coating method to coat a first metal layer on a film substrate to obtain a first metal film;

[0007] S2, connecting the non-woven fabric, the end of the first metal film is compositely connected to the non-woven fabric by an adhesive, and the width of the non-woven fabric is smaller than the width of the first metal film;

[0008] S3, preparing the electrode sheet, coating the first metal film and the overlapping part of the first metal film and the non-woven fabric with active slurry, and forming an active material layer after the active slurry is cured, thereby obtaining the electrode sheet, wherein the active slurry is made by mixing a conductive agent, a binder and a negative electrode active material;

[0009] S4, preparation of the tab, coating a thermally conductive layer on the surface of the non-woven fabric away from the first metal layer, and after the thermally conductive layer is solidified, vacuum coating is used to coat a second metal layer on the thermally conductive layer, thereby producing a lithium-ion battery cell.

[0010] Furthermore, in the step S1, the film substrate is a PE film, a PP film or a PET film.

[0011] Furthermore, in step S3, the material of the first metal layer of the electrode is copper;

[0012] At this time, the active slurry is mixed by 5-10 parts of a conductive agent, 60-70 parts of a binder and 20-30 parts of a negative electrode active material; wherein the conductive agent includes artificial graphite and a mixed solvent composed of ethyl acetate and tetrahydrofuran, the mass ratio of ethyl acetate to tetrahydrofuran is 3:2, and the mass ratio of artificial graphite to the mixed solvent is 1-3:1.5-5; the binder is butadiene rubber, and the negative electrode active material is acetylene carbon black or carbon nanotubes.

[0013] Furthermore, in step S3, the material of the first metal layer of the pole piece is aluminum;

[0014] At this time, the active slurry is mixed with 10-20 parts of a conductive agent, 60-70 parts of a binder and 10-30 parts of a negative electrode active material; wherein the conductive agent is a mixture of one of lamellar graphite, graphene, carbon nanotubes or carbon fibers and diisobutyl ester and isobutyl methacrylate, wherein the ratio of diisobutyl ester to methacrylate is 1:2 by mass, and its mass accounts for 70-80% of the conductive agent, the binder is butadiene rubber, and the negative electrode active material is any one of lithium cobalt oxide, lithium manganese oxide and lithium iron phosphate.

[0015] Furthermore, in the step S2, after the active slurry is coated on the first metal film and the overlapping portion of the first metal film and the non-woven fabric, it is baked at 90-100° C. for 1-2 minutes to solidify the active slurry.

[0016] Furthermore, in the step S2, an adhesive is applied at 4-8 cm from the end of the first metal film, and the non-woven fabric and the first metal film are composited by rolling.

[0017] Furthermore, in step S4, the thermal conductive layer is prepared by mixing 10-20 parts of an auxiliary agent, 50-60 parts of an adhesive and 10-15 parts of aluminum nitride powder.

[0018] Furthermore, the auxiliary agent is composed of 30-40 parts of sodium methylene bisnaphthalene sulfonate and 60-70 parts of carbon nanotubes.

[0019] Furthermore, in the step S4, after coating the heat-conducting layer, the heat-conducting layer is baked at 50-100° C. for 5-6 minutes to solidify the heat-conducting layer.

[0020] Furthermore, in step S4, the material of the second metal layer is nickel or aluminum.

[0021] On the other hand, the present invention also provides a lithium ion battery cell, which is improved in that it includes a film substrate, a first metal layer, an active material layer, a non-woven fabric, a heat conductive layer and a second metal layer;

[0022] The first metal layer is plated on the film substrate to form a first metal film; one end of the non-woven fabric is compositely connected to the end of the first metal film through an adhesive, and the width of the non-woven fabric is smaller than the width of the first metal film;

[0023] The heat-conducting layer is coated on the surface of the non-woven fabric away from the first metal layer, and the second metal layer is plated on the outer surface of the heat-conducting layer.

[0024] In the above structure, the film substrate is a PE film, a PP film or a PET film.

[0025] In the above structure, the material of the first metal layer is copper or aluminum, and the material of the second metal layer is nickel or aluminum.

[0026] On the other hand, the present invention further provides a lithium ion battery, the improvement of which lies in that the battery cell of the lithium ion battery is obtained by the above-mentioned method for manufacturing the battery cell of the lithium ion battery.

[0027] The beneficial effect of the present invention is that it avoids the occurrence of burrs at the welding joints caused by the welding connection of the pole ears and pole pieces in traditional battery cells, which may pierce the diaphragm during subsequent battery use, causing the positive and negative electrodes to directly contact and cause a battery short circuit, leading to battery combustion or even explosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a schematic flow chart of a method for manufacturing a lithium-ion battery cell.

[0029] Figure 2 It is a schematic structural diagram of a first metal film and a non-woven fabric in a method for manufacturing a lithium-ion battery cell of the present invention.

[0030] Figure 3 It is a schematic cross-sectional view of a pole piece produced in step S3 of a method for producing a lithium-ion battery cell of the present invention.

[0031] Figure 4 It is a cross-sectional schematic diagram of a lithium-ion battery cell of the present invention. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0033] The following will clearly and completely describe the concept, specific structure and technical effects of the present invention in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by technicians in this field without creative work are all within the scope of protection of the present invention. In addition, all the connection / connection relationships involved in the patent do not refer to the direct connection of components, but refer to the formation of a better connection structure by adding or reducing connection accessories according to the specific implementation situation. The various technical features in the invention can be combined interchangeably without conflicting with each other.

[0034] Example 1

[0035] Reference Figure 1 As shown, the present invention discloses a method for manufacturing a lithium-ion battery cell. Specifically, the manufacturing method comprises the following steps:

[0036] S1. Preparation of a first metal film, using a vacuum coating method to plate a first metal layer 20 on a film substrate 10 to obtain a first metal film 50; in this embodiment, the film substrate 10 is a PE film, and the material of the first metal layer 20 is copper, that is, a copper-plated layer is formed;

[0037] S2, connection of the non-woven fabric 30, applying adhesive 4 cm from the end of the first metal film 50, and realizing the compounding of the non-woven fabric 30 and the first metal film 50 by rolling; in this scheme, after the active slurry is applied to the first metal film 50 and the overlapping part of the first metal film 50 and the non-woven fabric 30, it is baked at 90° C. for 2 minutes to solidify the active slurry and form an active material layer 40;

[0038] Furthermore, the width of the non-woven fabric 30 is smaller than the width of the first metal film 50. Figure 2 As shown, the distance between the upper edge of the non-woven fabric 30 and the upper edge of the first metal film 50 is L, L=2 cm, and the distance between the lower edge of the non-woven fabric 30 and the lower edge of the first metal film 50 is L2, L2=2 cm;

[0039] S3, preparation of the electrode sheet, coating the first metal film 50 and the overlapping part of the first metal film 50 and the non-woven fabric 30 with active slurry, and forming an active material layer 40 after the active slurry is cured, thereby obtaining the electrode sheet, wherein the active slurry is made by mixing a conductive agent, a binder and a negative electrode active material;

[0040] In step S3, the active slurry is mixed with 10 parts of a conductive agent, 70 parts of a binder and 30 parts of a negative electrode active material. It can be understood that in this embodiment, the number of conductive agents, binders and negative electrode active materials is used to reflect the ratio of the three. In this embodiment, the weight ratio of the conductive agent, the binder and the negative electrode active material is 10:70:30. Similarly, the same meaning is also expressed in the following embodiments, and this article will not explain it in detail. Among them, the conductive agent includes artificial graphite and a mixed solvent composed of ethyl acetate and tetrahydrofuran. The mass ratio of ethyl acetate to tetrahydrofuran is 3:2, and the mass ratio of artificial graphite to the mixed solvent is 3:5; the binder is butadiene rubber, and the negative electrode active material is acetylene carbon black;

[0041] S4, preparation of the pole ear, coating a heat-conducting layer 60 on the surface of the non-woven fabric 30 away from the first metal layer 20, and after the heat-conducting layer 60 is cured, a second metal layer 70 is plated on the heat-conducting layer 60 by vacuum coating, and the second metal layer 70, the heat-conducting layer 60 and the non-woven fabric 30 constitute the pole ear; in this solution, the material of the second metal layer 70 is nickel, so as to obtain a lithium-ion battery cell; in addition, for the curing method of the heat-conducting layer 60, a specific embodiment is provided, after coating the heat-conducting layer 60, baking at 50°C for 6 minutes to cure the heat-conducting layer 60; due to the added heat-conducting layer 60, when the lithium-ion battery is heated inside, the heat can be promptly conducted away from the pole ear, so that the temperature inside the lithium-ion battery drops rapidly, reducing the possibility of explosion and combustion of the lithium-ion battery.

[0042] In the step S4, the heat-conducting layer 60 is made by mixing 10 parts of an auxiliary agent, 50 parts of an adhesive and 10 parts of aluminum nitride powder, and the auxiliary agent is composed of 30 parts of sodium methylene bisnaphthalene sulfonate and 6 parts of carbon nanotubes.

[0043] Through the above process, the structure of the lithium-ion battery cell is as follows: Figure 4 As shown, the thickness of the active material layer 40 on the non-woven fabric 30 is H1, the thickness of the thermal conductive layer 60 is H2, and the thickness of the second metal layer 70 is H3, H1 = H2 + H3. Therefore, the upper surface of the second metal layer 70 is on the same horizontal plane as the upper surface of the active material layer 40.

[0044] Through the above process, the present invention provides a method for manufacturing a lithium-ion battery cell. The entire manufacturing method does not require welding or other methods, which avoids the burrs that appear at the welding point between the pole ear and the pole piece in the traditional welding process, and prevents the burrs from piercing the diaphragm so that the positive and negative electrodes are in direct contact and short circuit, thereby improving the safety performance of the lithium-ion battery. In addition, since there is no welding process, the quality of the lithium-ion battery is greatly reduced, the energy density is improved, and the process and manufacturing cost are correspondingly reduced. In addition, through the connection process of the non-woven fabric 30 and the first metal film 50 in step S2, it is not easy to break at the connection point, which improves the tensile strength of the battery cell.

[0045] In summary, the lithium-ion battery provided by the present invention, on the one hand, avoids the burrs at the welding joints caused by the welding connection of the pole ears and pole pieces in the traditional battery, which may pierce the diaphragm during the subsequent use of the battery, causing the positive and negative electrodes to directly contact and cause the battery to short-circuit, causing the battery to burn or even explode. In addition, the present invention uses a material with an inner layer of heat-conducting material, which can conduct away the heat generated by the battery, thereby improving the safety performance of the battery.

[0046] Example 2

[0047] Reference Figure 1 As shown, the present invention discloses a method for manufacturing a lithium-ion battery cell. Specifically, the manufacturing method comprises the following steps:

[0048] S1, preparing the first metal film 50, using a vacuum coating method to plate a first metal layer 20 on a film substrate 10 to obtain the first metal film 50; in this embodiment, the film substrate 10 is a PE film, and the material of the first metal layer 20 is copper, that is, a copper-plated layer is formed;

[0049] S2, connection of the non-woven fabric 30, coating adhesive at 8 cm from the end of the first metal film 50, and realizing the compounding of the non-woven fabric 30 and the first metal film 50 by rolling; in this scheme, after coating the first metal film 50 and the overlapping part of the first metal film 50 and the non-woven fabric 30 with active slurry, baking at 100° C. for 1 min to solidify the active slurry and form an active material layer 40;

[0050] Furthermore, the width of the non-woven fabric 30 is smaller than the width of the first metal film 50. Figure 2 As shown, the distance between the upper edge of the non-woven fabric 30 and the upper edge of the first metal film 50 is L, L=3 cm, and the distance between the lower edge of the non-woven fabric 30 and the lower edge of the first metal film 50 is L2, L2=3 cm;

[0051] S3, preparation of the electrode sheet, coating the first metal film 50 and the overlapping part of the first metal film 50 and the non-woven fabric 30 with active slurry, and forming an active material layer 40 after the active slurry is cured, thereby obtaining the electrode sheet, wherein the active slurry is made by mixing a conductive agent, a binder and a negative electrode active material;

[0052] In step S3, the active slurry is prepared by mixing 5 parts of a conductive agent, 60 parts of a binder and 20 parts of a negative electrode active material; wherein the conductive agent comprises artificial graphite and a mixed solvent composed of ethyl acetate and tetrahydrofuran, the mass ratio of ethyl acetate to tetrahydrofuran is 3:2, and the mass ratio of artificial graphite to the mixed solvent is 1:1.5; the binder is butadiene rubber, and the negative electrode active material is carbon nanotubes;

[0053] S4, preparation of the pole ear, coating a heat-conducting layer 60 on the surface of the non-woven fabric 30 away from the first metal layer 20, and after the heat-conducting layer 60 is cured, a second metal layer 70 is plated on the heat-conducting layer 60 by vacuum coating, and the second metal layer 70, the heat-conducting layer 60 and the non-woven fabric 30 constitute the pole ear; in this solution, the material of the second metal layer 70 is nickel, so as to obtain a lithium-ion battery cell; in addition, for the curing method of the heat-conducting layer 60, a specific embodiment is provided, after coating the heat-conducting layer 60, baking at 100°C for 5 minutes to cure the heat-conducting layer 60; due to the added heat-conducting layer 60, when the lithium-ion battery generates heat inside, the heat can be promptly conducted away from the pole ear, so that the temperature inside the lithium-ion battery drops rapidly, reducing the possibility of explosion and combustion of the lithium-ion battery.

[0054] In the step S4, the heat-conducting layer 60 is made by mixing 20 parts of an auxiliary agent, 60 parts of an adhesive and 15 parts of aluminum nitride powder, and the auxiliary agent is composed of 40 parts of sodium methylene bisnaphthalene sulfonate and 70 parts of carbon nanotubes.

[0055] Through the above process, the structure of the lithium-ion battery cell is as follows: Figure 4 As shown, the thickness of the active material layer 40 on the non-woven fabric 30 is H1, the thickness of the thermal conductive layer 60 is H2, and the thickness of the second metal layer 70 is H3, H1 = H2 + H3. Therefore, the upper surface of the second metal layer 70 is on the same horizontal plane as the upper surface of the active material layer 40.

[0056] Through the above process, the present invention provides a method for manufacturing a lithium-ion battery cell. The entire manufacturing method does not require welding or other methods, which avoids the burrs that appear at the welding point between the pole ear and the pole piece in the traditional welding process, and prevents the burrs from piercing the diaphragm so that the positive and negative electrodes are in direct contact and short circuit, thereby improving the safety performance of the lithium-ion battery. In addition, since there is no welding process, the quality of the lithium-ion battery is greatly reduced, the energy density is improved, and the process and manufacturing cost are correspondingly reduced. In addition, through the connection process of the non-woven fabric 30 and the first metal film 50 in step S2, it is not easy to break at the connection point, which improves the tensile strength of the battery cell.

[0057] In summary, the lithium-ion battery provided by the present invention, on the one hand, avoids the burrs at the welding joints caused by the welding connection of the pole ears and pole pieces in the traditional battery, which may pierce the diaphragm during the subsequent use of the battery, causing the positive and negative electrodes to directly contact and cause the battery to short-circuit, causing the battery to burn or even explode. In addition, the present invention uses a material with an inner layer of heat-conducting material, which can conduct away the heat generated by the battery, thereby improving the safety performance of the battery.

[0058] Example 3

[0059] Reference Figure 1 As shown, the present invention discloses a method for manufacturing a lithium-ion battery cell. Specifically, the manufacturing method comprises the following steps:

[0060] S1. Preparation of the first metal film 50: vacuum coating is used to coat the first metal layer 20 on the film substrate 10 to obtain the first metal film 50; in this embodiment, the film substrate 10 is a PP film, and the material of the first metal layer 20 is aluminum, that is, an aluminum-plated layer is formed;

[0061] S2, connection of the non-woven fabric 30, applying adhesive 4 cm from the end of the first metal film 50, and realizing the compounding of the non-woven fabric 30 and the first metal film 50 by rolling; in this scheme, after the active slurry is applied to the first metal film 50 and the overlapping part of the first metal film 50 and the non-woven fabric 30, it is baked at 90° C. for 2 minutes to solidify the active slurry and form an active material layer 40;

[0062] Furthermore, the width of the non-woven fabric 30 is smaller than the width of the first metal film 50. Figure 2 As shown, the distance between the upper edge of the non-woven fabric 30 and the upper edge of the first metal film 50 is L, L=2 cm, and the distance between the lower edge of the non-woven fabric 30 and the lower edge of the first metal film 50 is L2, L2=2 cm;

[0063] S3, preparation of pole pieces, coating the first metal film 50 and the overlapping part of the first metal film 50 and the non-woven fabric 30 with active slurry, and forming an active material layer 40 after curing the active slurry, thereby obtaining a pole piece, wherein the active slurry is mixed with a conductive agent, a binder and a negative electrode active material; in step S3, the active slurry is mixed with 10 parts of a conductive agent, 60 parts of a binder and 10 parts of a negative electrode active material; wherein the conductive agent is composed of lamellar graphite and diisobutyl ester and isobutyl methacrylate in a mass ratio of 1:2, and the solvent accounts for 70% of the mass of the entire conductive agent, the binder is butadiene rubber, and the negative electrode active material is lithium cobalt oxide.

[0064] S4, preparation of the pole ear, coating a heat-conducting layer 60 on the surface of the non-woven fabric 30 away from the first metal layer 20, and after the heat-conducting layer 60 is cured, a second metal layer 70 is plated on the heat-conducting layer 60 by vacuum coating, and the second metal layer 70, the heat-conducting layer 60 and the non-woven fabric 30 constitute the pole ear; in this solution, the material of the second metal layer 70 is aluminum, thereby obtaining a lithium-ion battery cell; in addition, for the curing method of the heat-conducting layer 60, a specific embodiment is provided, after coating the heat-conducting layer 60, baking at 75°C for 5.5 minutes to cure the heat-conducting layer 60; due to the added heat-conducting layer 60, when the lithium-ion battery generates heat inside, the heat can be promptly conducted away from the pole ear, so that the temperature inside the lithium-ion battery drops rapidly, reducing the possibility of explosion and combustion of the lithium-ion battery.

[0065] In the step S4, the heat-conducting layer 60 is made by mixing 20 parts of an auxiliary agent, 60 parts of an adhesive and 15 parts of aluminum nitride powder, and the auxiliary agent is composed of 40 parts of sodium methylene bisnaphthalene sulfonate and 70 parts of carbon nanotubes.

[0066] Through the above process, the structure of the lithium-ion battery cell is as follows: Figure 4 As shown, the thickness of the active material layer 40 on the non-woven fabric 30 is H1, the thickness of the thermal conductive layer 60 is H2, and the thickness of the second metal layer 70 is H3, H1 = H2 + H3. Therefore, the upper surface of the second metal layer 70 is on the same horizontal plane as the upper surface of the active material layer 40.

[0067] Through the above process, the present invention provides a method for manufacturing a lithium-ion battery cell. The entire manufacturing method does not require welding or other methods, which avoids the burrs that appear at the welding point between the pole ear and the pole piece in the traditional welding process, and prevents the burrs from piercing the diaphragm so that the positive and negative electrodes are in direct contact and short circuit, thereby improving the safety performance of the lithium-ion battery. In addition, since there is no welding process, the quality of the lithium-ion battery is greatly reduced, the energy density is improved, and the process and manufacturing cost are correspondingly reduced. In addition, through the connection process of the non-woven fabric 30 and the first metal film 50 in step S2, it is not easy to break at the connection point, which improves the tensile strength of the battery cell.

[0068] Example 4

[0069] Reference Figure 1 As shown, the present invention discloses a method for manufacturing a lithium-ion battery cell. Specifically, the manufacturing method comprises the following steps:

[0070] S1, preparing the first metal film 50, using a vacuum coating method to coat the first metal layer 20 on the film substrate 10 to obtain the first metal film 50; in this embodiment, the film substrate 10 is a PET film, and the material of the first metal layer 20 is aluminum, that is, an aluminum-plated layer is formed;

[0071] S2, connecting the non-woven fabric 30, applying adhesive at 6 cm from the end of the first metal film 50, and realizing the compounding of the non-woven fabric 30 and the first metal film 50 by rolling; in this scheme, after the active slurry is applied to the first metal film 50 and the overlapping part of the first metal film 50 and the non-woven fabric 30, it is baked at 95° C. for 1.5 min to solidify the active slurry and form an active material layer 40;

[0072] Furthermore, the width of the non-woven fabric 30 is smaller than the width of the first metal film 50. Figure 2 As shown, the distance between the upper edge of the non-woven fabric 30 and the upper edge of the first metal film 50 is L, L = 2.5 cm, and the distance between the lower edge of the non-woven fabric 30 and the lower edge of the first metal film 50 is L2, L2 = 2.5 cm;

[0073] S3, preparation of the electrode sheet, coating the first metal film 50 and the overlapping part of the first metal film 50 and the non-woven fabric 30 with active slurry, and forming an active material layer 40 after the active slurry is cured, thereby obtaining the electrode sheet, wherein the active slurry is made by mixing a conductive agent, a binder and a negative electrode active material;

[0074] In step S3, the active slurry is prepared by mixing 15 parts of a conductive agent, 65 parts of a binder and 20 parts of a negative electrode active material; wherein the conductive agent is composed of carbon nanotubes and a 1:2 ratio of diisobutyl ester and isobutyl methacrylate, and the mixed solvent accounts for 80% of the total conductive agent by mass, the binder is butadiene rubber, and the negative electrode active material is lithium manganate.

[0075] S4, preparation of the pole ear, coating a heat-conducting layer 60 on the surface of the non-woven fabric 30 away from the first metal layer 20, and after the heat-conducting layer 60 is cured, a second metal layer 70 is plated on the heat-conducting layer 60 by vacuum coating, and the second metal layer 70, the heat-conducting layer 60 and the non-woven fabric 30 constitute the pole ear; in this solution, the material of the second metal layer 70 is aluminum, thereby obtaining a lithium-ion battery cell; in addition, for the curing method of the heat-conducting layer 60, a specific embodiment is provided, after coating the heat-conducting layer 60, baking at 80°C for 6 minutes to cure the heat-conducting layer 60; due to the added heat-conducting layer 60, when the lithium-ion battery generates heat inside, the heat can be promptly conducted away from the pole ear, so that the temperature inside the lithium-ion battery drops rapidly, reducing the possibility of explosion and combustion of the lithium-ion battery.

[0076] In the step S4, the heat-conducting layer 60 is made by mixing 15 parts of an auxiliary agent, 55 parts of an adhesive and 13 parts of aluminum nitride powder, and the auxiliary agent is composed of 35 parts of sodium methylene bisnaphthalene sulfonate and 65 parts of carbon nanotubes.

[0077] Through the above process, the structure of the lithium-ion battery cell is as follows: Figure 4 As shown, the thickness of the active material layer 40 on the non-woven fabric 30 is H1, the thickness of the thermal conductive layer 60 is H2, and the thickness of the second metal layer 70 is H3, H1 = H2 + H3. Therefore, the upper surface of the second metal layer 70 is on the same horizontal plane as the upper surface of the active material layer 40.

[0078] Through the above process, the present invention provides a method for manufacturing a lithium-ion battery cell. The entire manufacturing method does not require welding or other methods, which avoids the burrs that appear at the welding point between the pole ear and the pole piece in the traditional welding process, and prevents the burrs from piercing the diaphragm so that the positive and negative electrodes are in direct contact and short circuit, thereby improving the safety performance of the lithium-ion battery. In addition, since there is no welding process, the quality of the lithium-ion battery is greatly reduced, the energy density is improved, and the process and manufacturing cost are correspondingly reduced. In addition, through the connection process of the non-woven fabric 30 and the first metal film 50 in step S2, it is not easy to break at the connection point, which improves the tensile strength of the battery cell.

[0079] Example 5

[0080] Combination Figure 4As shown, the present invention discloses a lithium-ion battery cell, which is manufactured by any one of the above-mentioned embodiments 1 to 4. Specifically, the lithium-ion battery cell includes a film substrate 10, a first metal layer 20, an active material layer 40, a non-woven fabric 30, a heat-conducting layer 60 and a second metal layer 70, wherein the first metal layer 20 is plated on the film substrate 10 to form a first metal film 50; one end of the non-woven fabric 30 is compositely connected with the end of the first metal film 50 by an adhesive, and the width of the non-woven fabric 30 is smaller than the width of the first metal film 50; the heat-conducting layer 60 is coated on the surface of the non-woven fabric 30 away from the first metal layer 20, and the second metal layer 70 is plated on the outer surface of the heat-conducting layer 60. The material of the first metal layer 20 is copper or aluminum, and the material of the second metal layer 70 is nickel or aluminum.

[0081] Furthermore, the film substrate 10 is any one of a PE film, a PP film and a PET film. In this embodiment, the film substrate 10 is a PE film. Figure 2 As shown, the distance between the upper edge of the non-woven fabric 30 and the upper edge of the first metal film 50 is L1, and its value range is 2-3 cm. The distance between the lower edge of the non-woven fabric 30 and the lower edge of the first metal film 50 is L2, and its value range is also 2-3 cm. Through the connection between the non-woven fabric 30 and the first metal film 50, the active material layer 40 is coated on the first metal film 50, so that the non-woven fabric 30 and the first metal film 50 are connected as a whole. The connection between the non-woven fabric 30 and the first metal film 50 is achieved through rolling and compounding. On the one hand, compared with the welding method, this method avoids the generation of burrs. On the other hand, it can ensure the connection strength between the non-woven fabric 30 and the first metal film 50, and the connection is not easy to break, which improves the tensile strength.

[0082] In this embodiment, if Figure 4 As shown, the thickness of the active material layer 40 on the non-woven fabric 30 is H1, the thickness of the thermal conductive layer 60 is H2, the thickness of the second metal layer 70 is H3, and H1=H2+H3; and, the thickness of the non-woven fabric 30 is H4, and the thickness of the active material layer 40 above the first metal layer 20 is H5, and H5=H2+H3+H4.

[0083] On the other hand, the present invention further discloses a lithium ion battery, the battery cell of which is obtained by the above-mentioned method for manufacturing the lithium ion battery cell.

[0084] The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A method for manufacturing a lithium-ion battery cell, characterized in that: The manufacturing method comprises the following steps: S1. Preparation of a first metal film, by vacuum coating a first metal layer on a film substrate to obtain a first metal film; the film substrate is a PE film, a PP film or a PET film; S2, connecting the non-woven fabric, the end of the first metal film is compositely connected to the non-woven fabric by an adhesive, and the width of the non-woven fabric is smaller than the width of the first metal film; S3, preparing the electrode sheet, coating the first metal film and the overlapping part of the first metal film and the non-woven fabric with active slurry, and forming an active material layer after the active slurry is cured, thereby obtaining the electrode sheet, wherein the active slurry is made by mixing a conductive agent, a binder and a negative electrode active material; S4, preparation of the tab, coating a thermally conductive layer on the surface of the non-woven fabric away from the first metal layer, and after the thermally conductive layer is solidified, vacuum coating is used to coat a second metal layer on the thermally conductive layer, thereby producing a lithium-ion battery cell.

2. The method for manufacturing a lithium-ion battery cell according to claim 1, characterized in that: In the step S3, the material of the first metal layer of the pole piece is copper; At this time, the active slurry is mixed by 5-10 parts of a conductive agent, 60-70 parts of a binder and 20-30 parts of a negative electrode active material; wherein the conductive agent includes artificial graphite and a mixed solvent composed of ethyl acetate and tetrahydrofuran, the mass ratio of ethyl acetate to tetrahydrofuran is 3:2, and the mass ratio of artificial graphite to the mixed solvent is 1-3:1.5-5; the binder is butadiene rubber, and the negative electrode active material is acetylene carbon black or carbon nanotubes.

3. The method for manufacturing a lithium-ion battery cell according to claim 1, characterized in that: In the step S3, the material of the first metal layer of the pole piece is aluminum; At this time, the active slurry is mixed with 10-20 parts of a conductive agent, 60-70 parts of a binder and 10-30 parts of a negative electrode active material; wherein the conductive agent includes a mixture of one of flake graphite, graphene, carbon nanotubes or carbon fibers and diisobutyl ester and isobutyl methacrylate, the ratio of diisobutyl ester to methacrylate is 1:2 by mass, and the mass accounts for 70-80% of the conductive agent, the binder is butadiene rubber, and the negative electrode active material is any one of lithium cobalt oxide, lithium manganese oxide and lithium iron phosphate.

4. The method for manufacturing a lithium-ion battery cell according to claim 1, characterized in that: In the step S2, after the active slurry is coated on the first metal film and the overlapping portion of the first metal film and the non-woven fabric, it is baked at 90-100° C. for 1-2 minutes to solidify the active slurry.

5. The method for manufacturing a lithium-ion battery cell according to claim 1, characterized in that: In the step S2, an adhesive is applied at 4-8 cm from the end of the first metal film, and the non-woven fabric and the first metal film are laminated by rolling.

6. The method for manufacturing a lithium-ion battery cell according to claim 1, characterized in that: In the step S4, the thermal conductive layer is prepared by mixing 10-20 parts of an auxiliary agent, 50-60 parts of an adhesive and 10-15 parts of aluminum nitride powder.

7. The method for manufacturing a lithium-ion battery cell according to claim 6, characterized in that: The auxiliary agent is composed of 30-40 parts of sodium methylene bisnaphthalene sulfonate and 60-70 parts of carbon nanotubes.

8. The method for manufacturing a lithium-ion battery cell according to claim 1, characterized in that: In the step S4, after coating the heat-conducting layer, the heat-conducting layer is baked at 50-100° C. for 5-6 minutes to solidify the heat-conducting layer.

9. The method for manufacturing a lithium-ion battery cell according to claim 1, characterized in that: In the step S4, the material of the second metal layer is nickel or aluminum.

10. A lithium-ion battery cell, characterized in that: The lithium-ion battery cell is obtained by the method for manufacturing a lithium-ion battery cell according to any one of claims 1 to 9, comprising a film substrate, a first metal layer, an active material layer, a non-woven fabric, a heat-conducting layer and a second metal layer; The first metal layer is plated on the film substrate to form a first metal film; one end of the non-woven fabric is compositely connected to the end of the first metal film through an adhesive, and the width of the non-woven fabric is smaller than the width of the first metal film; The heat-conducting layer is coated on the surface of the non-woven fabric away from the first metal layer, and the second metal layer is plated on the outer surface of the heat-conducting layer.

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