Surface treatment of lithium ion battery components

Abstract

The present disclosure provides surface treatment of lithium ion battery components. The invention relates to a manufacturing method for forming an electrode. In one provided method, an oxide layer is removed from a surface of a metal current collector via ionization. The solventless dry powder agglomerates of active material, binder, and conductive agent are then calendered onto a surface of a metal current collector to form an electrode.

Description

Technical Field

[0001] In at least one aspect, a method for making a lithium-ion battery is provided. Background Art

[0002] The manufacture of battery electrodes has traditionally utilized a wet process involving solvents, requiring long drying times and solvent recovery systems. While widely used, this process has also caused several problems. Dry electrode processes have emerged as an alternative to address these issues by eliminating the need for solvents, thereby simplifying the manufacturing process.

[0003] However, utilizing dry processes can present its own challenges, such as reduced adhesion between the composite layer and the metal substrate, which can lead to delamination. This delamination can impact battery performance, increasing resistance and reducing energy capacity and lifetime. Attempts to increase adhesion, such as applying a carbon primer coating or etching the metal surface, have been explored, but these introduce additional processing steps. Summary of the Invention

[0004] In one aspect of the present disclosure, a manufacturing method is provided. The manufacturing method includes removing an oxide layer from the surface of a metal current collector via ionization, and then rolling a solvent-free dry agglomerate of an active material, a binder, and a conductive agent onto the surface of the metal current collector to form an electrode. The ionization source can be a laser. The surface and the ionization source can be separated by a distance in the range of 0 to 1.25 m. The metal current collector can be a foil. In embodiments where the metal current collector is a foil, the foil can be an aluminum foil or a copper foil. The manufacturing method can also include cutting the electrode into individual electrode assemblies.

[0005] In another aspect of the present disclosure, another manufacturing method is provided. The manufacturing method includes ionizing the surface of a metal foil current collector and bonding a solvent-free agglomerate of an active material, a binder, and a conductive agent to the surface of the metal current collector to form an electrode. The ionization source can be a laser. The surface and the ionization source can be separated by a distance in the range of 0 to 1.25 m. The metal current collector can be a foil. In embodiments where the metal current collector is a foil, the foil can be an aluminum foil or a copper foil. The manufacturing method can also include cutting the electrode into individual electrode assemblies. The bonding can include lamination, and in other embodiments, the bonding can include calendaring.

[0006] In another aspect of the present disclosure, another manufacturing method is provided. The manufacturing method includes oxidizing the surface of a metal current collector by exposing it to an ionization source, and laminating a solvent-free dry powder agglomerate of an active material, a binder, and a conductive agent onto the surface of the metal current collector to form an electrode. The ionization source can be a laser. The metal current collector can be a foil. The manufacturing method can also include cutting the electrode into individual electrode assemblies. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For a further understanding of the nature, objects and advantages of the present disclosure, reference should be made to the following detailed description, read in conjunction with the following drawings, in which like reference numerals represent like elements, and wherein:

[0008] Figure 1 is a schematic diagram of a manufacturing apparatus according to one or more aspects of the present disclosure;

[0009] Figure 2A and Figure 2B is a schematic diagram of a battery component according to one or more embodiments of the present disclosure;

[0010] Figure 3 is a flow chart of a manufacturing method according to one or more embodiments of the present disclosure;

[0011] Figure 4 is a flow chart of a manufacturing method according to one or more embodiments of the present disclosure; and

[0012] Figure 5 is a flow chart of a manufacturing method according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0013] Reference will now be made in detail to the presently preferred compositions, embodiments, and methods of the present invention. The drawings are not necessarily drawn to scale. However, it should be understood that the disclosed embodiments are merely illustrative of the present invention, which may be embodied in various forms and alternatives. Therefore, the specific details disclosed herein are not to be construed as limiting, but merely as a representative basis for any aspect of the present invention and / or for teaching one skilled in the art to employ the present invention in various ways.

[0014] The present disclosure relates to a method designed to improve efficiency and reduce the overhead associated with battery manufacturing. A continuous online process that avoids the addition of foreign materials is envisioned. The process is characterized in that it utilizes an online surface treatment of a metal foil (a component in the battery construction). In one aspect of the present disclosure, a technique for surface treatment is proposed that involves applying a laser or other light source, either alone or in combination. The method is designed to activate a binder material on the surface of a composite film, thereby increasing the adhesion between the layers. This enhancement is crucial for reducing interlayer resistance, which in turn contributes to excellent battery performance.

[0015] One of the advantages of this method is that it has the potential to simplify the manufacturing process, thereby reducing the time and energy associated with production. By focusing on activating the binder material through surface treatment, the process aims to eliminate the need for additional materials, thereby simplifying the manufacturing line.

[0016] Furthermore, the process's adaptability to surface treatment using a variety of light sources provides application flexibility, ensuring it can be tailored to meet specific manufacturing needs. This adaptability extends to the treatment of different metal foil materials, such as aluminum and copper, highlighting the method's versatility.

[0017] Now refer to Figures 1 to 2B , Figure 1 A manufacturing apparatus 10, as outlined in one or more aspects of the present disclosure, is shown. The apparatus includes an initial reactor 12 for dry-mixing active material, a binder, and a conductive agent to produce a dry powder mixture 14. This mixture is then processed by rollers 16 into an active material layer 18. Simultaneously, a web foil 20, unrolled at rollers 22, is surface-treated by an ionization source 24, which may be a laser, plasma, or corona source. This step increases the surface adhesion of the web foil 20 by ionizing or oxidizing the surface of the web foil 20. The foil 20 can be made of a variety of metals, such as aluminum, copper, or any other suitable material. Following surface treatment, the active material layer 18 is combined with the treated web foil 26 by calendaring at rollers 28 to produce an electrode 30. The treatment process, intended to increase adhesion, requires removing the oxide layer from the foil using the ionization source 24, which is positioned at a specific distance to effectively treat the surface of the foil, now referred to as the treated web foil 26. As shown, both sides of the foil 20 can be surface-treated and calendared, enabling the production of double-sided electrodes. However, the process can be similarly applied to single-sided electrodes.

[0018] Figure 2A The web foil 20 is shown in its original state before surface treatment, having a relatively smooth and possibly oxidized surface that may limit adhesion to the active material layer 20 . Figure 2B The treated web foil 26 is shown after application of an ionization source 24, which may be a laser, plasma, or corona source. The treated foil 26 exhibits changes in the surface texture of the foil, including increased roughness and microstructures that increase surface adhesion. These modifications result from removing the oxide layer and increasing the surface area of ​​the foil, thereby increasing bonding capabilities with the active material layer 18 for electrode construction.

[0019] Figure 3is a flow chart of a manufacturing method 32 according to one or more embodiments of the present disclosure. Initially, at step 34, the oxide layer is removed from the surface of the metal current collector via ionization, which may affect the electrical and mechanical properties of the metal current collector. The process involves the use of an ionization source, such as a laser, which can be controlled to effectively remove the oxide layer without altering the underlying current collector. The optimal distance between the surface and the ionization source can be maintained in the range of 0 to 1.25 meters to achieve uniform oxide removal. In a final step 36, a solvent-free dry powder agglomerate of active material, binder and conductive agent is calendered onto the surface of the metal current collector to form an electrode.

[0020] Figure 4 is a flow chart of a manufacturing method 38 according to one or more embodiments of the present disclosure. Initially, at step 40, the surface of the metal foil current collector is ionized. This step can remove impurities and modify the surface structure, potentially increasing its ability to bond with electrode materials. The process can involve the use of an ionization source, such as a laser, which can be controlled to perform effective surface modification without altering the underlying current collector. The laser can be focused at an optimal distance between the surface and the ionization source in the range of 0 to 1.25 meters to achieve uniform treatment.

[0021] In the final step 42, the solvent-free agglomerate of active material, binder, and conductive agent is bonded to the surface of a metal current collector to form an electrode. This bonding can be achieved by methods such as lamination or calendaring, depending on the desired properties in electrode production. Method 34 is applicable to a variety of current collectors, such as foil current collectors, including those made of aluminum or copper. The method may also include a further step of cutting the electrodes into individual assemblies for practical use in battery manufacturing.

[0022] Figure 5 A flow chart 44 is shown according to one or more embodiments of the present disclosure. At step 46, the surface of the metal current collector is oxidized by exposure to an ionization source. This step intentionally oxidizes the surface, which may affect the electrical and mechanical properties of the metal current collector. The ionization source (such as a laser) can be precisely controlled to effectively oxidize the surface without changing the current collector below. The optimal distance between the surface and the ionization source can be maintained in the range of 0 to 1.25 meters to achieve uniform oxidation.

[0023] In the final step 48, the solvent-free dry powder agglomerates of active material, binder, and conductive agent are laminated onto the oxidized surface of a metal current collector to form the electrode. This process involves bonding the agglomerates to the current collector, potentially increasing the adhesion and uniformity of the electrode layer. The current collector can be any suitable current collector, such as aluminum or copper. The method can also include cutting the electrodes into individual assemblies for use in battery manufacturing.

[0024] Throughout this specification (including the appended claims), unless explicitly described otherwise, the word "comprises" and variations such as "comprises" or "comprising" will be understood to mean including the stated elements, steps, or components but not omitting any other elements, steps, components, or groups thereof. This interpretation also applies to the terms "include" and "have" and their derivatives.

[0025] Unless otherwise indicated, the term "about" when used in conjunction with numerical values ​​in this document refers to a variation of ±5% from the specified amount. This term is intended to encompass minor variations that may occur due to manufacturing tolerances or measurement inaccuracies. For example, "about 50" should be interpreted to mean from 47.5 to 52.5.

[0026] As used herein, the term "substantially free" means that a composition, method, or article is free of a specified component (e.g., a solvent) or has only an insignificant amount of the component such that the absence does not materially affect the basic or novel characteristics of the composition, method, or article. For example, a process described as "substantially solvent-free" means that no solvent is present.

[0027] Unless the context indicates otherwise, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents. For example, reference to "a binder" includes a single binder as well as a mixture of two or more binders. The use of "and / or" in this document is intended to encompass both conjunctive and disjunctive forms of the terms it connects. That is, "A and / or B" should be understood to mean "A, B, or A and B."

[0028] As used herein, "operably connected" or "operably coupled" refers to a configuration of elements in which the elements are arranged so that they can cooperate or interact to achieve a desired function or result. The term is intended to encompass direct connections, indirect connections through intermediate elements, and wireless connections.

[0029] In the context of this disclosure, "enhancement" refers to both qualitative and quantitative changes in a property or performance characteristic when compared to a baseline or standard process, composition, or device. For example, "enhanced adhesion" refers to a measurable increase in the strength of a bond between two materials achieved by the methods described herein.

[0030] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it should be understood that various changes can be made without departing from the spirit and scope of the disclosed material.

[0031] As previously described, features of the various embodiments may be combined to form additional embodiments that may not be explicitly described or shown in this disclosure. Although various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, it will be recognized by those of ordinary skill in the art that one or more features or characteristics may be compromised to achieve desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, strength, durability, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. For this reason, embodiments that are described as being less desirable than other embodiments or prior art implementations with respect to one or more characteristics are within the scope of this disclosure and may be desirable for a particular application.

[0032] According to the present invention, a manufacturing method includes: removing an oxide layer from a surface of a metal current collector via ionization; and calendaring a solvent-free dry powder agglomerate of an active material, a binder, and a conductive agent onto the surface of the metal current collector to form an electrode.

[0033] In one aspect of the invention, the source for ionization is a laser.

[0034] In one aspect of the invention, the surface and the source for ionization are separated by a distance in the range of 0 to 1.25 m.

[0035] In one aspect of the invention, the metal current collector is a foil.

[0036] In one aspect of the invention, the foil is aluminum foil.

[0037] In one aspect of the invention, the foil is a copper foil.

[0038] In one aspect of the invention, the method includes cutting the electrode into individual electrode assemblies.

[0039] According to the present invention, a manufacturing method includes ionizing a surface of a metal current collector and bonding a solvent-free agglomerate of an active material, a binder, and a conductive agent to the surface of the metal current collector to form an electrode.

[0040] In one aspect of the invention, the source for ionization is a laser.

[0041] In one aspect of the invention, the surface and the source for ionization are separated by a distance in the range of 0 to 1.25 m.

[0042] In one aspect of the invention, the metal current collector is a foil.

[0043] In one aspect of the invention, the foil is aluminum foil.

[0044] In one aspect of the invention, the foil is a copper foil.

[0045] In one aspect of the invention, the method includes cutting the electrode into individual electrode assemblies.

[0046] In one aspect of the invention, bonding comprises lamination.

[0047] In one aspect of the invention, joining comprises calendering.

[0048] According to the present invention, a manufacturing method includes oxidizing the surface of a metal current collector by exposure to an ionization source, and laminating a solvent-free dry powder agglomerate of an active material, a binder, and a conductive agent onto the surface of the metal current collector to form an electrode.

[0049] In one aspect of the invention, the ionization source is a laser.

[0050] In one aspect of the invention, the metal current collector is a foil.

[0051] In one aspect of the invention, the method includes cutting the electrode into individual electrode assemblies.

Claims

1. A manufacturing method comprising: Removing the oxide layer from the surface of the metal current collector via ionization; as well as A solvent-free dry powder agglomerate of active material, binder and conductive agent is calendared onto the surface of the metal current collector to form an electrode.

2. The manufacturing method according to claim 1, wherein the source for the ionization is a laser.

3. The manufacturing method of claim 1, wherein the surface and the source for the ionization are separated by a distance in the range of 0 to 1.25 m. The manufacturing method of claim 1 , wherein the metal current collector is a foil. The manufacturing method according to claim 4 , wherein the foil is an aluminum foil. The manufacturing method according to claim 4 , wherein the foil is a copper foil.

7. The manufacturing method according to claim 1, further comprising cutting the electrode into individual electrode assemblies.

8. A manufacturing method comprising: ionizing the surface of the metal current collector; as well as A solvent-free agglomerate of active material, binder, and conductive agent is bonded to the surface of the metal current collector to form an electrode.

9. The manufacturing method of claim 8, wherein the source for the ionization is a laser.

10. The manufacturing method of claim 8, wherein the surface and the source for the ionization are separated by a distance in the range of 0 to 1.25 m.

11. The manufacturing method of claim 8, wherein the metal current collector is a foil.

12. The manufacturing method according to claim 11, wherein the foil is an aluminum foil.

13. The manufacturing method according to claim 11, wherein the foil is a copper foil.

14. The manufacturing method of claim 8, further comprising cutting the electrode into individual electrode assemblies.

15. The manufacturing method of claim 8, wherein the bonding comprises lamination.

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