Lithium ion battery component with polar binder

Abstract

The present disclosure provides a lithium ion battery component with a polar binder. A lithium ion battery component is presented. The invention relates to a lithium ion battery component having an electrode with a current collector and an electrode sheet laminated thereon, the electrode sheet comprising a conductive agent and a polarity-crosslinkable B-A-B binder, the binder mechanically binding the conductive agent in a spatially stable dispersion, the spatially stable dispersion is configured to allow volume expansion of the electrode sheet during charging of the electrode and to facilitate volume shrinkage of the electrode sheet during discharging of the electrode.

Description

Technical Field

[0001] The present disclosure relates to electrode materials for lithium-ion batteries. Background Art

[0002] In the development of lithium-ion battery (LIB) electrodes, traditional manufacturing techniques typically rely on the use of solvents to mix and adhere active materials and conductors to form electrode films. These methods present certain challenges. In addition, the drying process required to remove the solvent can be energy-intensive and may affect the integrity of the electrode structure.

[0003] Polytetrafluoroethylene (PTFE), a binder widely used in the manufacture of LIB electrodes due to its chemical stability and mechanical strength, presents challenges. Despite PTFE's beneficial properties, its inherent non-polar nature can lead to poor adhesion and cohesion with the polar surfaces of conductors and active materials. This can result in suboptimal dispersion of these components. To address these challenges, there is growing interest in developing solvent-free methods for producing LIB electrodes. Summary of the Invention

[0004] In one aspect of the present disclosure, a lithium-ion battery component is provided. The lithium-ion battery component includes an electrode having a current collector and an electrode sheet laminated thereon. The electrode sheet includes a conductive agent and a polar cross-linkable BAB binder. The binder mechanically binds the conductive agent in a sterically stable dispersion. The sterically stable dispersion is configured to allow volume expansion of the electrode sheet during electrode charging and promote volume contraction of the electrode sheet during electrode discharge. The B group in the polar cross-linkable BAB binder can be an acrylate or epoxy resin. The A group in the polar cross-linkable BAB binder can be a polyurethane, epoxy resin, or ethylene glycol. The conductive agent can include carbon black and carbon nanotubes. The electrode sheet includes an active material. The active material can include lithium. In other configurations, the active material can include graphite. The polar cross-linkable BAB binder can have a viscosity of at least 500 centipoise at 25 degrees Celsius. The polar cross-linkable BAB binder can have a molecular weight of at least 200 g / mol.

[0005] In another aspect of the present disclosure, a method is proposed. The method begins by mixing a gel-oligomer with a conductive agent to form a spatially dispersed mixture. The electrode active material is then added to the spatially dispersed mixture to form a self-supporting electrode film, and the self-supporting electrode film is rolled with a current collector to form a laminated electrode. The gel-oligomer can be a polar cross-linkable BAB binder. The B group in the polar cross-linkable BAB binder can be selected from one of an acrylate or an epoxy resin. The A group in the polar cross-linkable BAB binder can be selected from one of a polyurethane, an epoxy resin, or an ethylene glycol.

[0006] In another aspect of the present disclosure, a lithium-ion battery is provided. The lithium-ion battery comprises: a separator; and a pair of electrodes sandwiching the separator, at least one of the electrodes comprising an electrode sheet laminated with a current collector, the electrode sheet comprising a conductive agent, the conductive agent being sterically stabilized by a polar cross-linkable BAB binder that mechanically bonds the dispersed conductive agent. The B group in the polar cross-linkable BAB binder may be selected from one of an acrylate or an epoxy resin. The A group in the polar cross-linkable BAB binder may be selected from one of a polyurethane, an epoxy resin, or an ethylene glycol. The conductive agent may comprise carbon black and carbon nanotubes. The electrode sheet may comprise an active material. The polar cross-linkable BAB binder may have a viscosity of at least 500 centipoise at 25 degrees Celsius. In some configurations, the polar cross-linkable BAB binder has a molecular weight of at least 200 g / mol. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic diagram of a BAB binder and its substituents according to any one or more aspects of the present disclosure;

[0008] Figure 2 is a schematic diagram of a lithium ion according to any one or more aspects of the present disclosure;

[0009] Figure 3 is a schematic diagram of a manufacturing process according to any one or more aspects of the present disclosure; and

[0010] Figure 4 is a flow chart of a manufacturing process according to any one or more aspects of the present disclosure. DETAILED DESCRIPTION

[0011] Embodiments are described herein. However, it should be understood that the disclosed embodiments are merely examples and that other embodiments may take various and alternative forms. The drawings are not necessarily drawn to scale. Some features may be exaggerated or minimized to illustrate details of particular components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art.

[0012] The various features shown and described with reference to any one of the accompanying drawings may be combined with features shown in one or more other drawings to produce embodiments not explicitly shown or described. The combinations of features shown provide representative embodiments for typical applications. However, for specific applications or implementations, various combinations and modifications of features may be desired consistent with the teachings of this disclosure.

[0013] The present disclosure relates to the manufacture of lithium ion battery (LIB) components and to increasing the adhesion in electrode structures by assembling them. Gel-type crosslinkable oligomers are introduced as binding agents. These oligomers are polar binding agents and adopt the form of crosslinkable BAB-type monomers and / or oligomers. The specific physical properties of BAB-type binding agents are a viscosity of at least 500 centipoise and a molecular weight of at least 200 grams per mole at 25 degrees Celsius. These properties enable the binding agent to act as a liquid gel, thereby promoting the solvent-free dispersion of conductors and electrode materials.

[0014] The binder design includes two different types of functional groups. The 'A' component is substituted with polar groups (such as polyurethane, epoxy resin and ethylene glycol), which promote particle dispersion and adhesion to the current collector. The 'B' component includes groups such as acrylates and epoxy resins, which are central to forming a strong film after the binder cures. The use of BAB binders is adaptable, allowing them to be used independently or in combination with other binders including PTFE.

[0015] A lithium-ion battery component according to one or more aspects of the present disclosure comprises an electrode having a current collector and an electrode sheet laminated on top. The sheet may include a conductive agent mixed with a polar cross-linkable BAB binder to achieve a dispersion that supports volume changes of the electrode sheet during the charge and discharge cycles of the battery. The conductive agent (such as carbon black and carbon nanotubes) is selected based on its contribution to the conductivity of the electrode. The active material used for the energy storage and release capabilities of the battery may be lithium, graphite, etc.

[0016] The manufacturing process according to one or more aspects of the present disclosure involves mixing a gel-oligomer binder with a conductive agent to produce a uniformly dispersed mixture. After the active material is added, this results in the formation of a self-supporting electrode film. The subsequent step of rolling the film with the current collector ultimately results in a laminated electrode in which the conductive agent is mechanically bonded in a configuration that facilitates volume adjustment. In an assembled battery according to one or more embodiments, a separator and a pair of electrodes are provided, at least one of which integrates the disclosed electrode sheet and current collector arrangement. This arrangement is intended to maintain the dimensional stability and mechanical integrity of the electrode. By the methods outlined, gel-type cross-linkable oligomers can be incorporated into lithium-ion batteries.

[0017] Now refer to Figure 1, a schematic diagram of a BAB-type binder 10 is shown. The BAB-type binder 10 can be a gel-type cross-linkable oligomer incorporated into a lithium-ion battery. The binder 10 has one A functional group 12 and two B functional groups 14. Although one A functional group and two B functional groups are shown, the BAB-type binder 10 can have one or more of each corresponding functional group. The A group 12 can be substituted by polyurethane, epoxy resin, ethylene glycol or any other suitable group. The A group 12 substituent is selected from polar functional groups that promote particle dispersion and surface adhesion to the collector. The B group 14 can be substituted by acrylate, epoxy resin or any other suitable group. For the mechanical robustness of the binder, the B group 14 substituent is selected from a cross-linkable moiety. An example of a suitable BAB-type binder is diurethane dimethacrylate. The BAB-type binder 10 is a gel-type cross-linkable oligomer that has initial solvent-like properties for spatial dispersion and provides durable electrode film properties through strong cross-linking between its molecules after curing. Steric stabilization refers to the process used to prevent particles within a dispersion from clumping together. In the context of lithium-ion battery manufacturing, steric stabilization is achieved by coating the surface of conductive agents such as carbon black and carbon nanotubes with macromolecules, such as gel-type crosslinkable oligomers 10. This coating helps maintain a uniform dispersion of these agents within the binder matrix, achieving consistent conductivity throughout the electrode. Additionally, it accommodates volume changes during the battery's charge and discharge cycles.

[0018] exist Figure 2 , a lithium-ion battery component 16 is shown. The lithium-ion battery component 16 shown is a lithium-ion battery cell. The lithium-ion battery cell 16 has a separator 18 sandwiching a pair of electrodes 20 and 22. The electrode 20 has an electrode sheet 24 laminated with a current collector 26, the current collector having a conductive agent 28 that is spatially stabilized by a polar cross-linkable BAB binder 10, the polar cross-linkable BAB binder mechanically binding the dispersed conductive agent 28 in a spatially stabilized dispersion 30. The spatially stabilized dispersion 30 is configured to allow volume expansion of the electrode sheet 24 during charging of the electrode 20 and to promote volume contraction of the electrode sheet 24 during discharge of the electrode 20. Although the electrode 20 is shown as having an electrode sheet 24, the electrode sheet 24 can be incorporated into either or both electrodes. The conductive agent 28 can be carbon black, carbon nanotubes, or any other material with suitable electrochemical properties. The electrode sheet 24 includes an active material 32. Depending on the application, the active material 32 may be an anode or cathode material, such as lithium or graphite.

[0019] To form the electrode sheet 24, a polar cross-linkable BAB binder 10 is mixed with a conductive agent 28 until the conductor 28 is sterically stable. A suitable active material 32 is then added to the binder 10 along with the sterically stable conductive agent 28 to form the electrode sheet 24. The active material 32 may optionally be mixed with a fibrillated binder such as polytetrafluoroethylene. Figure 3 In the embodiment, the electrode sheet 24 is fed through rollers 34 and laminated with the current collector 26. The laminated electrode 20 may be further cured by thermal curing, a catalytic process, UV curing, electron beam laser application, or any other suitable method to promote crosslinking.

[0020] Figure 4 3 is a flow chart of a manufacturing method according to one or more embodiments of the present disclosure. In box 38, the method 36 begins by mixing a gel-oligomer with a conductive agent to form a spatially dispersed mixture. The gel-oligomer can be a BAB type binder having one or more A functional groups and one or more B functional groups. The A group substituent is selected from polar functional groups that promote particle dispersion and surface adhesion to the collector. The A group substituent can be a polyurethane, epoxy resin, ethylene glycol or any other suitable group. For the mechanical robustness of the binder, the B group substituent is selected from a cross-linkable part. The B group substituent can be an acrylate, epoxy resin or any other suitable group. The conductive agent can be carbon black or carbon nanotubes. Then in box 40, an electrode active material is added to the spatially dispersed mixture to form a self-supporting electrode film. Depending on the application, the active material can be an anode or cathode material, such as lithium or graphite.

[0021] In frame 42, the self-supporting electrode film is rolled with the current collector to form a laminated electrode. In some configurations, the laminated electrode can be further cured by thermal curing, catalytic process, UV curing, electron beam laser application or any other suitable method to promote crosslinking. Thermal curing involves heating the material, which triggers a chemical reaction that leads to crosslinking of polymer chains within the binder. Compared to thermal curing, catalytic curing accelerates the chemical reaction at a lower temperature or in a shorter time. Using ultraviolet light, UV curing triggers the curing process without the need for heating, resulting in rapid crosslinking of the binder.

[0022] Electron beam curing uses high-energy electrons to initiate crosslinking, resulting in very fast cure times and deep penetration into the material. It's an environmentally friendly option that cures materials without solvents, resulting in strong, chemically resistant films. This method is particularly effective when uniform curing across the entire thickness of the material is required.

[0023] 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 these disclosures.

[0024] As previously mentioned, features of the various embodiments may be combined to form additional embodiments of the invention that may not be explicitly described or shown. 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, and the like. 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.

[0025] According to the present invention, a lithium-ion battery component is provided, comprising: an electrode having a current collector and an electrode sheet laminated thereon, the electrode sheet comprising a conductive agent and a polar cross-linkable BAB binder, the binder mechanically binding the conductive agent in a spatially stable dispersion, the spatially stable dispersion being configured to allow volume expansion of the electrode sheet during charging of the electrode and to promote volume contraction of the electrode sheet during discharge of the electrode.

[0026] According to an embodiment, the B group in the polar cross-linkable BAB binder is selected from one of acrylate and epoxy resin.

[0027] According to an embodiment, the A group in the polar cross-linkable BAB binder is selected from one of polyurethane, epoxy resin and ethylene glycol.

[0028] According to an embodiment, the conductive agent includes carbon black and carbon nanotubes.

[0029] According to an embodiment, the electrode sheet comprises an active material.

[0030] According to an embodiment, the active material includes lithium.

[0031] According to an embodiment, the active material comprises graphite.

[0032] According to an embodiment, the polar cross-linkable BAB binder has a viscosity of at least 500 centipoise at 25 degrees Celsius.

[0033] According to an embodiment, the polar crosslinkable BAB binder has a molecular weight of at least 200 g / mol.

[0034] According to the present invention, a method includes: mixing a gel-oligomer with a conductive agent to form a spatially dispersed mixture; adding an electrode active material to the spatially dispersed mixture to form a self-supporting electrode film; and rolling the self-supporting electrode film with a current collector to form a laminated electrode.

[0035] In one aspect of the present invention, the gel-oligomer is a polar cross-linkable BAB binder.

[0036] In one aspect of the present invention, the B group in the polar cross-linkable BAB binder is selected from one of acrylate and epoxy resin.

[0037] In one aspect of the present invention, the A group in the polar cross-linkable BAB binder is selected from one of polyurethane, epoxy resin and ethylene glycol.

[0038] According to the present invention, there is provided a lithium ion battery having: a separator; and a pair of electrodes sandwiching the separator, at least one of the electrodes comprising an electrode sheet laminated with a current collector, the electrode sheet having a dispersed conductive agent, the dispersed conductive agent being spatially stabilized by a polar cross-linkable BAB binder that mechanically binds the dispersed conductive agent.

[0039] According to an embodiment, the B group in the polar cross-linkable BAB binder is selected from one of acrylate and epoxy resin.

[0040] According to an embodiment, the A group in the polar cross-linkable BAB binder is selected from one of polyurethane, epoxy resin and ethylene glycol.

[0041] According to an embodiment, the conductive agent includes carbon black and carbon nanotubes.

[0042] According to an embodiment, the electrode sheet comprises an active material.

[0043] According to an embodiment, the polar cross-linkable BAB binder has a viscosity of at least 500 centipoise at 25 degrees Celsius.

[0044] According to an embodiment, the polar crosslinkable BAB binder has a molecular weight of at least 200 g / mol.

Claims

1. A lithium-ion battery component comprising: An electrode having a current collector and an electrode sheet laminated thereon, the electrode sheet comprising a conductive agent and a polar cross-linkable BAB binder, the binder mechanically binding the conductive agent in a sterically stable dispersion, the sterically stable dispersion being configured to allow volume expansion of the electrode sheet during charging of the electrode and to promote volume contraction of the electrode sheet during discharging of the electrode. 2 . The lithium-ion battery component of claim 1 , wherein the B group in the polar cross-linkable BAB binder is selected from one of acrylate and epoxy resin. 3 . The lithium ion battery component of claim 1 , wherein the A group in the polar cross-linkable BAB binder is selected from one of polyurethane, epoxy resin and ethylene glycol.

4. The lithium ion battery component of claim 1, wherein the conductive agent comprises carbon black and carbon nanotubes.

5. The lithium ion battery component of claim 1, wherein the electrode sheet comprises an active material.

6. The lithium-ion battery component of claim 5, wherein the active material comprises lithium.

7. The lithium ion battery component of claim 5, wherein the active material comprises graphite.

8. The lithium ion battery component of claim 1, wherein the polar cross-linkable BAB binder has a viscosity of at least 500 centipoise at 25 degrees Celsius.

9. The lithium ion battery component of claim 1, wherein the polar cross-linkable BAB binder has a molecular weight of at least 200 g / mole.

10. A method comprising: mixing the gel-oligomer with a conductive agent such that a spatially dispersed mixture is formed; adding an electrode active material to the spatially dispersed mixture to form a self-supporting electrode film; as well as The self-supporting electrode film is rolled with a current collector to form a laminated electrode.

11. The method of claim 10, wherein the gel-oligomer is a polar cross-linkable BAB binder. 12 . The method of claim 11 , wherein the B group of the polar cross-linkable BAB binder is selected from one of acrylate and epoxy resin.

13. The method of claim 11, wherein the A group in the polar cross-linkable BAB binder is selected from one of polyurethane, epoxy resin and ethylene glycol.

14. A lithium-ion battery comprising: partitions; as well as A pair of electrodes sandwiching the separator, at least one of the electrodes comprising an electrode sheet laminated with a current collector, the electrode sheet having a dispersed conductive agent spatially stabilized by a polar cross-linkable BAB binder mechanically binding the dispersed conductive agent. 15 . The lithium ion battery of claim 14 , wherein the B group in the polar cross-linkable BAB binder is selected from one of acrylate and epoxy resin.

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