Surface treatment of lithium-ion battery components

Abstract

The disclosure relates to manufacturing methods for forming electrodes. In one provided method, an oxidized layer is removed from a surface of a metal current collector by ionization. A solvent-free dry powder agglomeration of active materials, binders, and conductive agents is then calendered onto the surface of the metal current collector to form an electrode.

Description

FIELD OF TECHNOLOGY

[0001] In at least one aspect, methods for manufacturing lithium-ion batteries are provided. BACKGROUND

[0002] Battery electrode manufacturing traditionally uses a wet process involving solvents, requiring long drying times and solvent recycling systems. Despite its widespread use, this process raises some concerns. The dry electrode process has emerged as an alternative to address these issues by eliminating the need for solvents, thereby simplifying the manufacturing process.

[0003] However, using the dry process can present its own challenges, such as reduced adhesion between the composite material layer and the metal substrate, which can lead to delamination. This delamination can impair battery performance, increase resistance, and reduce energy capacity and lifetime. Attempts to increase adhesion, such as applying carbon primer coatings or etching the metal surface, have been investigated, but require additional processing steps. SUMMARY

[0004] In one aspect of the disclosure, a manufacturing method is presented. The manufacturing method involves removing an oxidized layer from a surface of a metal current collector by ionization and then calendering a solvent-free dry agglomeration of active materials, binders, and conductive agents onto the surface of the metal current collector to form an electrode. The ionization source may be a laser. The surface and the ionization source may be separated by a distance ranging from 0 to 1.25 m. The metal current collector may be a foil. In embodiments where the metal current collector is a foil, it may be aluminum foil or copper foil. The manufacturing method may further include cutting the electrode into individual electrode assemblies.

[0005] In another aspect of the disclosure, another manufacturing method is presented. The manufacturing method includes ionizing a surface of a metal foil current collector and bonding a solvent-free agglomeration of active materials, binders, and conductive agents onto the surface of the metal current collector to form an electrode. The ionization source may be a laser. The surface and the ionization source may be separated by a distance ranging from 0 to 1.25 m. The metal current collector may be a foil. In embodiments where the metal current collector is a foil, it may be aluminum foil or copper foil. The manufacturing method may further include cutting the electrode into individual electrode assemblies. The bonding may include lamination, and in other embodiments, the bonding may include calendering.

[0006] In another aspect of the disclosure, another manufacturing method is presented. The manufacturing method includes oxidizing a surface of a metal current collector by exposure to an ionization source and laminating a solvent-free dry powder agglomeration of active materials, binders, and conductive agents onto the surface of the metal current collector to form an electrode. The ionization source may be a laser. The metal current collector may be a foil. The manufacturing method may further include cutting the electrode into individual electrode assemblies. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For a fuller understanding of the nature, objects, and advantages of the present disclosure, reference should be made to the following detailed description taken in conjunction with the following drawings, in which like reference numerals designate like elements and in which: Fig. 1 is a schematic illustration of a manufacturing facility according to one or more aspects of the disclosure; Fig. 2A and Fig. 2B are schematic views of a battery component according to one or more embodiments of the disclosure; Fig. 3 is a flow diagram of a manufacturing method according to one or more embodiments of the disclosure; Fig. 4 is a flow diagram of a manufacturing method according to one or more embodiments of the disclosure; and Fig. 5 is a flow diagram of a manufacturing method according to one or more embodiments of the disclosure. DETAILED DESCRIPTION

[0008] Description will now be made in detail of presently preferred compositions, embodiments, and methods of the present invention. The figures are not necessarily to scale. It should be understood, however, that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for any aspect of the invention and / or as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0009] This disclosure relates to an approach designed to increase efficiency and reduce the effort associated with battery manufacturing. A continuous in-line process is contemplated that avoids the addition of foreign materials. The process features the use of in-line surface treatment for metal foils, a component in the construction of batteries. In one aspect of the disclosure, a surface treatment technique is presented that includes the application of laser or other light sources, either singly or in combination. This process is designed to activate bonding materials on the surface of the composite foil, thereby increasing the adhesion force between layers. Such an improvement is crucial for reducing interlayer resistance, which in turn contributes to superior battery performance.

[0010] One of the advantages of this approach is its potential to optimize the manufacturing process, reducing both the time and energy associated with production. By focusing on the activation of binding materials through surface treatment, the processes aim to eliminate the need for additional materials, simplifying the manufacturing chain.

[0011] Furthermore, the process's adaptability to utilize different light sources for surface treatment offers flexibility in application, ensuring it can be tailored to specific manufacturing requirements. This adaptability extends to the treatment of different metal foil materials, such as aluminum and copper, underscoring the process's versatility.

[0012] With reference now to the Fig. 1-2B shows Fig. 1 illustrates a manufacturing facility 10 as set forth in one or more aspects of the disclosure. The apparatus includes an initial reactor 12 for the dry mixing of active materials, binders, and conductive agents, resulting in a dry powder mixture 14. This mixture is then processed by rollers 16 into an active material layer 18. Simultaneously, a web foil 20 unwound from roller 22 is subjected to a surface treatment 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 its surface. The foil 20 may be made of a variety of metals, such as aluminum, copper, or any other suitable material.After surface treatment, the active material layer 18 is combined with the treated web film 26 by calendering on rollers 28, producing an electrode 30. The treatment process, aimed at increasing adhesion, involves removing an oxidized layer from the film using the ionization source 24, which is set at a specific distance to effectively treat the surface of the film, now referred to as the treated web film 26. As shown, the surface treatment and calendering can be performed on both sides of the film 20, enabling the production of two-sided electrodes. However, this process can equally be applied to single-sided electrodes.

[0013] Fig. Figure 2A shows the web film 20 before surface treatment in its initial state with a relatively smooth and possibly oxidized surface, which could limit adhesion to the active material layer 20. Fig. Figure 2B shows the treated web foil 26 after application of the ionization source 24, which can be a laser, plasma, or corona source. The treated foil 26 exhibits changes in the surface texture of the foil, including increased roughness and the creation of microstructures that enhance surface adhesion. These modifications result from the removal of the oxidized layer and an increase in the surface area of ​​the foil, thereby increasing the bonding ability with the active material layer 18 for the electrode structure.

[0014] Fig. 3 shows a flow diagram of a manufacturing method 32 according to one or more embodiments of the disclosure. Initially, at step 34, an oxidized layer is removed from the surface of a metal current collector by ionization, which step can influence the electrical and mechanical properties of the metal current collector. This process involves the use of an ionization source, such as a laser, which can be controlled to effectively remove an oxidized layer without altering the underlying current collector. The optimal distance between the surface and the ionization source can be maintained within a range of 0 to 1.25 meters for uniform oxidation removal. In a final step 36, a solvent-free dry powder agglomeration of active materials, binders, and conductive agents is calendered onto the surface of the metal current collector to form an electrode.

[0015] Fig. 4 shows a flow diagram of a manufacturing method 38 according to one or more embodiments of the disclosure. Initially, at step 40, the surface of a metal foil current collector is ionized. This step can remove contaminants and modify the surface structure, potentially increasing its ability to bond with an electrode material. This process can involve using an ionization source, such as a laser, that can be controlled for effective surface modification without altering the underlying current collector. The laser can be focused at a distance between the surface and the ionization source in a range of 0 to 1.25 meters for uniform treatment.

[0016] In a final step 42, a solvent-free agglomeration of active materials, binders, and conductive agents is bonded to the ionized surface of the metal current collector to form an electrode. This bonding can be achieved by processes such as lamination or calendering, based on the desired properties in electrode production. The process 34 can be applied to a variety of current collectors, such as foil current collectors, including those made of aluminum or copper. The process can also include a further step of cutting the electrode into individual assemblies for practical application in battery manufacturing.

[0017] Fig.5 shows a flowchart 44 according to one or more embodiments of the disclosure. In step 46, the surface of a metal current collector is oxidized by exposing it to an ionization source. This step intentionally oxidizes the surface, which can affect the electrical and mechanical properties of the metal current collector. The ionization source, such as a laser, can be precisely controlled for effective oxidation of the surface without altering the underlying current collector. The optimal distance between the surface and the ionization source can be maintained within a range of 0 to 1.25 meters for uniform oxidation.

[0018] In a final step 48, a solvent-free dry powder agglomeration of active materials, binders, and conductive agents is laminated to the oxidized surface of the metal current collector to form an electrode. This process involves bonding the agglomeration 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. This process may also involve cutting the electrode into individual assemblies for use in battery manufacturing.

[0019] Throughout this specification, including the following claims, it is understood that the word "comprises" and variations such as "comprises" or "comprising" imply the inclusion of the specified elements, steps, or components, but not the omission of other elements, steps, components, or groups thereof, unless explicitly described otherwise. This interpretation also applies to the terms "include" and "comprise" and their derivatives.

[0020] The term "approximately," when used in this publication in conjunction with numerical values, refers to variations of ±5% from the specified quantity, unless otherwise noted. This term is intended to include minor deviations that may occur due to manufacturing tolerances or inaccuracies in measurement. For example, "approximately 50" should be interpreted to mean from 47.5 to 52.5.

[0021] The term "essentially free" as used in this document refers to compositions, processes, or articles that lack the specified component (e.g., a solvent) or that contain only insignificant amounts of the component such that its absence does not significantly affect the basic or novel properties of the composition, process, or article.

[0022] For example, a process described as “essentially solvent-free” implies that no solvents are present.

[0023] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context dictates otherwise. 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" throughout this specification is intended to include both the conjunctive and disjunctive forms of the terms connected therein. That is, "A and / or B" should be understood to mean "A, B, or A and B."

[0024] "Operatively connected" or "operably coupled," as used in this document, refers to a configuration of elements where the elements are arranged such that they can cooperate or interact to achieve a desired function or result. This term is intended to include direct connections, indirect connections through intermediate elements, and wireless connections.

[0025] In the context of this disclosure, "improved" refers to qualitative and quantitative changes in a property or performance characteristic compared to a baseline or standard process, composition, or apparatus. For example, "improved adhesion" refers to a measurable increase in the bond strength between two materials achieved by the methods described in this document.

[0026] While exemplary embodiments are described above, these embodiments are not intended to describe all possible forms covered by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosed subject matter.

[0027] As previously described, the features of various embodiments may be combined to form further embodiments of the disclosure that may not be explicitly described or illustrated. While various embodiments may have been described as providing advantages or being preferred over other prior art embodiments or implementations with respect to one or more desired characteristics, one of ordinary skill in the art will understand that one or more features or characteristics may be compromised to achieve desired overall system attributes depending on the specific application and implementation. These attributes may include, but are not limited to, strength, durability, market capacity, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc.Thus, embodiments that are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for certain applications.

[0028] According to the present invention, a manufacturing method includes: removing an oxidized layer from a surface of a metal current collector by ionization; and calendering a solvent-free dry powder agglomeration of active materials, binders, and conductive agents on the surface of the metal current collector to form an electrode.

[0029] In one aspect of the invention, a source of ionization is a laser.

[0030] In one aspect of the invention, the surface and a source of ionization are separated by a distance in a range of 0 to 1.25 m.

[0031] In one aspect of the invention, the metal current collector is a foil.

[0032] In one aspect of the invention, the foil is an aluminum foil.

[0033] In one aspect of the invention, the foil is a copper foil.

[0034] In one aspect of the invention, the method includes cutting the electrode into individual electrode assemblies.

[0035] According to the present invention, a manufacturing method includes: ionizing a surface of a metal current collector; and bonding a solvent-free agglomeration of active materials, binders, and conductive agents onto the surface of the metal current collector to form an electrode.

[0036] In one aspect of the invention, a source of ionization is a laser.

[0037] In one aspect of the invention, the surface and a source of ionization are separated by a distance in a range of 0 to 1.25 m.

[0038] In one aspect of the invention, the metal current collector is a foil.

[0039] In one aspect of the invention, the foil is an aluminum foil.

[0040] In one aspect of the invention, the foil is a copper foil.

[0041] In one aspect of the invention, the method includes cutting the electrode into individual electrode assemblies.

[0042] In one aspect of the invention, binding includes lamination.

[0043] In one aspect of the invention, binding includes calendering.

[0044] According to the present invention, a manufacturing method includes: oxidizing a surface of a metal current collector by exposure to an ionization source; and laminating a solvent-free dry powder agglomeration of active materials, binders, and conductive agents on the surface of the metal current collector to form an electrode.

[0045] In one aspect of the invention, an ionization source is a laser.

[0046] In one aspect of the invention, the metal current collector is a foil.

[0047] In one aspect of the invention, the method includes cutting the electrode into individual electrode assemblies.

Claims

[1] Manufacturing process comprising: Removing an oxidized layer from a surface of a metal current collector by ionization; and Calendering a solvent-free dry powder agglomeration of active materials, binders, and conductive agents onto the surface of the metal current collector to form an electrode. [2] A manufacturing method according to claim 1, wherein a source for the ionization is a laser. [3] A manufacturing method according to claim 1, wherein the surface and a source for ionization are separated by a distance in a range of 0 to 1.25 m. [4] The manufacturing method according to claim 1, wherein the metal current collector is a foil. [5] A manufacturing method according to claim 4, wherein the foil is an aluminum foil. [6] A manufacturing method according to claim 4, wherein the foil is a copper foil. [7] The manufacturing method of claim 1, further comprising cutting the electrode into individual electrode assemblies. [8] Manufacturing process comprising: Ionizing a surface of a metal current collector; and Bonding a solvent-free agglomeration of active materials, binders, and conductive agents to the surface of the metal current collector to form an electrode. [9] A manufacturing method according to claim 8, wherein a source for the ionization is a laser. [10] A manufacturing method according to claim 8, wherein the surface and a source of ionization are separated by a distance in a range of 0 to 1.25 m. [11] The manufacturing method according to claim 8, wherein the metal current collector is a foil. [12] A manufacturing method according to claim 11, wherein the foil is an aluminum foil. [13] A 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] A manufacturing method according to claim 8, wherein the bonding includes lamination.

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