Wire mesh current collector for electrode of battery cell with enhanced contact contact and reduced resistance
By coating and annealing metal coating on the wire mesh current collector of the battery pack electrode, combined with the arrangement of the active material layer, the problem of insufficient contact at the grid contacts is solved, which significantly reduces the internal resistance and improves the performance of the electrode and Battery endurance.
Patent Information
- Application Number
- CN202311429144.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-06-21
- Filing Date
- 2023-10-30
- Publication Date
- 2024-12-24
AI Technical Summary
The wire mesh current collector of the battery pack electrode lacks sufficient physical and electrical contact at the mesh contacts, resulting in an increase in internal resistance, affecting the performance and range of the electrode.
By immersing the wire mesh current collector in a metal salt bath to apply a metal coating and enhancing the physical and electrical contacts of the mesh contacts during annealing above the metal melting temperature of the metal coating below the metal melting temperature of the wire mesh current collector, In conjunction with the arrangement of anode or cathode active material layers, the strength and stiffness of the wire mesh current collector are improved.
It effectively reduces the internal resistance of the electrode, improves the physical strength and electrical contact of the electrode, enhances the rate performance of the lithium metal anode, and improves the adhesion of lithium to the current collector surface.
Smart Images
Figure CN119181809A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to wire mesh current collectors for electrodes of battery cells, and more particularly to methods of coating wire mesh current collectors for battery cells to enhance junction contact and reduce electrical resistance. Background Art
[0002] The information provided in this section is for the purpose of generally introducing the background of the present disclosure. No admission is made, either explicitly or implicitly, that the work of the presently named inventors described in this section is prior art to the present disclosure, nor is it admitted that the work is prior art to the present disclosure, as described in this section, which may not otherwise be identified as prior art at the time of filing.
[0003] Electric vehicles (EVs), such as battery electric vehicles (BEVs), hybrid electric vehicles, and / or fuel cell vehicles, include one or more motors and a battery system, which includes one or more battery cells, modules, and / or packs. A battery control module is used to control the charging and / or discharging of the battery system during charging and / or driving. EV manufacturers are committed to improving power density to increase the range of EVs. Summary of the invention
[0004] A method for manufacturing a current collector for an electrode of a battery cell includes providing a wire mesh current collector, the wire mesh current collector including a plurality of first wires and a plurality of second wires to be superimposed to form a plurality of grid contacts. The diameters of the plurality of first wires and the plurality of second wires are 4 μm to 100 μm. The method includes coating the wire mesh current collector with a metal coating by immersing the wire mesh current collector in a bath including a metal salt.
[0005] In other features, the plurality of first wires and the plurality of second wires of the wire mesh current collector are made of one or more metals selected from copper, stainless steel, brass, bronze, zinc, aluminum and alloys thereof. The metal coating comprises a metal selected from indium (In), tin (Sn), bismuth (Bi), zinc (Zn), nickel (Ni) and alloys thereof.
[0006] In other features, the method includes annealing the wire mesh current collector after coating the wire mesh current collector to enhance physical and electrical contact at the plurality of mesh junctions. The annealing is performed at a temperature above the melting temperature of the metal of the metal coating and below the melting temperature of the metal of the plurality of first wires and the plurality of second wires of the wire mesh current collector.
[0007] In other features, the method includes disposing an anode active material layer adjacent to a wire mesh current collector. The method includes disposing a cathode active material layer adjacent to a wire mesh current collector. The method includes coating the wire mesh current collector with a slurry comprising an anode active material. The method includes coating the wire mesh current collector with a slurry comprising a cathode active material.
[0008] In other features, the wire mesh current collector is immersed in the bath in discrete sections. The wire mesh current collector is immersed in the bath continuously from a roll.
[0009] A method for manufacturing a current collector for an electrode of a battery cell includes providing a wire mesh current collector, the wire mesh current collector including a plurality of first wires and a plurality of second wires to be superimposed to form a grid contact. The diameters of the plurality of first wires and the plurality of second wires are 4 μm to 100 μm. The plurality of first wires and the plurality of second wires of the wire mesh current collector are made of a metal selected from copper, stainless steel, brass, bronze, zinc, aluminum and alloys thereof. The method includes immersing the wire mesh current collector in a bath including a metal salt to coat the wire mesh current collector. The metal salt includes a metal selected from indium (In), tin (Sn), bismuth (Bi), zinc (Zn) and alloys thereof. The method includes annealing the wire mesh current collector after the wire mesh current collector passes through the bath.
[0010] In other features, the annealing is performed at a temperature above the melting temperature of the metal in the metal salt and below the melting temperature of the metal used in the wire mesh current collector. The method includes arranging an anode active material layer adjacent to the wire mesh current collector. The method includes arranging a cathode active material layer adjacent to the wire mesh current collector. The method includes coating the wire mesh current collector with a slurry comprising an anode active material. The method includes coating the wire mesh current collector with a slurry comprising a cathode active material.
[0011] In other features, the wire mesh current collector is immersed in the bath in discrete sections. The wire mesh current collector is immersed in the bath continuously from a roll.
[0012] The present disclosure relates to the following solutions:
[0013] Scheme 1. A method for manufacturing a current collector for an electrode of a battery cell, comprising:
[0014] A wire mesh current collector is provided, which includes a plurality of first wires and a plurality of second wires stacked to form a plurality of grid joints.
[0015] wherein the diameters of the plurality of first wires and the plurality of second wires are 4 μm to 100 μm; and
[0016] The wire mesh current collector is coated with the metal coating by immersing it in a bath containing a metal salt.
[0017] Option 2. The method according to Option 1, wherein the plurality of first wires and the plurality of second wires of the wire mesh current collector are made of one or more metals selected from copper, stainless steel, brass, bronze, zinc, aluminum and alloys thereof.
[0018] Option 3. A method according to Option 1, wherein the metal coating comprises a metal selected from the group consisting of indium (In), tin (Sn), bismuth (Bi), zinc (Zn), nickel (Ni) and alloys thereof.
[0019] Option 4. The method according to Option 1 further comprises annealing the wire mesh current collector after coating the wire mesh current collector to enhance physical and electrical contacts at the plurality of mesh junctions.
[0020] Option 5. A method according to Option 4, wherein the annealing is performed at a temperature higher than the melting temperature of the metal of the metal coating and lower than the melting temperature of the metal of the plurality of first wires and the plurality of second wires of the wire mesh current collector.
[0021] Option 6. The method according to Option 1 further includes arranging an anode active material layer adjacent to the wire mesh current collector.
[0022] Option 7. The method according to Option 1 further includes arranging a cathode active material layer adjacent to the wire mesh current collector.
[0023] Option 8. The method according to Option 1 further comprises coating the wire mesh current collector with a slurry containing an anode active material.
[0024] Option 9. The method according to Option 1 further comprises coating the wire mesh current collector with a slurry containing a cathode active material.
[0025] Option 10. The method according to Option 1, wherein the wire mesh current collector is immersed in a bath in discrete sections.
[0026] Option 11. A method according to Option 1, wherein the wire mesh current collector is continuously immersed in the bath from a coil.
[0027] Solution 12. A method for manufacturing a current collector for an electrode of a battery cell, comprising:
[0028] providing a wire mesh current collector, which includes a plurality of first wires and a plurality of second wires stacked to form a grid junction,
[0029] wherein the diameters of the plurality of first wires and the plurality of second wires are 4 μm to 100 μm, and
[0030] wherein the plurality of first wires and the plurality of second wires of the wire mesh current collector are made of a metal selected from the group consisting of copper, stainless steel, brass, bronze, zinc, aluminum and alloys thereof;
[0031] immersing the wire mesh current collector in a bath including a metal salt to coat the wire mesh current collector,
[0032] wherein the metal salt comprises a metal selected from the group consisting of indium (In), tin (Sn), bismuth (Bi), zinc (Zn) and alloys thereof; and
[0033] The wire mesh current collector is annealed after passing through the bath.
[0034] Option 13. A method according to Option 12, wherein the annealing is performed at a temperature higher than the melting temperature of the metal in the metal salt and lower than the melting temperature of the metal used in the wire mesh current collector.
[0035] Option 14. The method according to Option 12 further includes arranging an anode active material layer adjacent to the wire mesh current collector.
[0036] Option 15. The method according to Option 12 further includes arranging a cathode active material layer adjacent to the wire mesh current collector.
[0037] Option 16. The method according to Option 12 further comprises coating the wire mesh current collector with a slurry containing an anode active material.
[0038] Option 17. The method according to Option 12 further comprises coating the wire mesh current collector with a slurry containing a cathode active material.
[0039] Option 18. A method according to Option 12, wherein the wire mesh current collector is immersed in a bath in discrete sections.
[0040] Option 19. A method according to Option 12, wherein the wire mesh current collector is continuously immersed in the bath from a roll.
[0041] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims and drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] The present disclosure will be more fully understood from the detailed description and accompanying drawings, in which:
[0043] Figure 1 is a side cross-sectional view of one embodiment of a battery cell including an electrode having a coated wire mesh current collector according to the present disclosure;
[0044] Figure 2A and 2B is a plan view illustrating the tensile strength of an uncoated wire mesh current collector in two directions;
[0045] Figure 3A and 3B An embodiment of a method of coating and optionally annealing a wire mesh current collector according to the present disclosure is illustrated;
[0046] Figure 4A is a side view illustrating one embodiment of a wire mesh current collector after coating according to the present disclosure;
[0047] Figure 4B is an enlarged side view illustrating one embodiment of a wire mesh current collector after coating according to the present disclosure;
[0048] Figure 5A is a side view illustrating one embodiment of a wire mesh current collector after coating and annealing according to the present disclosure; and
[0049] Figure 5B is an enlarged side view illustrating one embodiment of a wire mesh current collector after coating and annealing.
[0050] In the drawings, reference numerals may be repeated to designate similar and / or identical elements. DETAILED DESCRIPTION
[0051] The battery cell includes an anode electrode, a cathode electrode, and a separator arranged in a stack in a predetermined order. The anode electrode includes an anode active layer arranged on one or both sides of an anode current collector. The cathode electrode includes a cathode active layer arranged on one or both sides of a cathode current collector. In some embodiments, the anode active material layer or the cathode active material layer includes a metal layer arranged adjacent to the current collector. In other embodiments, the anode active material layer or the cathode active material layer includes a coating applied to the anode current collector or the cathode current collector. The coating may include one or more anode active materials or cathode active materials, one or more binders, and one or more conductive fillers.
[0052] The anode and cathode current collectors may include foil, wire mesh, or expanded metal. For example, the wire mesh current collector may include wires made of copper (Cu), stainless steel (SS), brass, bronze, zinc (Zn), aluminum (Al), and alloys thereof (e.g., Cu-100 or SS-100). The wire mesh current collector may be made of wires having a thickness of 4 μm to 100 μm (e.g., 30 μm). In some embodiments, the wire mesh current collector has about 100 to 300 openings per square inch (e.g., 100).
[0053] The wires of the wire mesh current collector cross each other at the mesh junctions. Although the wires touch each other at the mesh junctions, the wires are not rigidly connected. As a result, the wire mesh current collector has low strength, stiffness, and / or resistance to deformation, making it difficult to handle during electrode manufacturing. For example, electrode manufacturing may include the use of a roll-to-roll manufacturing method that requires handling of the wire mesh current collector.
[0054] The present disclosure relates to methods for improving the strength and stiffness of wire mesh used as a three-dimensional current collector (3DCC) in an electrode of a battery cell. The gaps and / or lack of sufficient physical and / or electrical contact between the wires crossing at the mesh junctions of the wire mesh current collector increase the internal resistance of the current collector. The increased resistance increases heat generation and / or reduces the performance of the anode electrode and / or cathode electrode using the wire mesh current collector.
[0055] The wire mesh current collector according to the present disclosure is coated with a metal coating to increase rigidity and reduce resistance. In some embodiments, the metal coating is applied using electrodeposition. In some embodiments, the mesh junctions of the wire mesh current collector are further strengthened by annealing the coated wire mesh after applying the metal coating. Annealing remelts the coating. The molten coating further enters the mesh junctions of the wire mesh current collector under the action of capillary forces. The molten coating cools, solidifies, and more rigidly connects the cross wires at the mesh junctions.
[0056] In some embodiments, the metal coating comprises a metal material having a melting point lower than the melting temperature of the metal of the wire of the wire mesh current collector so that annealing can be optionally performed after coating. In some embodiments, the metal coating comprises one or more metals selected from tin (Sn), indium (In), bismuth (Bi), zinc (Zn), nickel (Ni) and alloys thereof. When the melting temperature of the metal in the metal coating is higher than the metal of the wire of the wire mesh current collector, annealing can be omitted. For example, if the wire of the wire mesh current collector is made of Cu and the metal coating comprises Ni, annealing is not performed because the melting temperature of Ni is higher than that of copper (Cu).
[0057] Reference now Figure 1 , the battery cell 10 includes cathode electrodes 20-1, 20-2, ..., and 20-C, where C is an integer greater than 1. The cathode electrode 20 includes a cathode active material layer 24 arranged on one or both sides of a cathode current collector 26. The battery cell 10 includes anode electrodes 40-1, 40-2, ..., and 40-A, where A is an integer greater than 1. The anode electrode 40 includes an anode active material layer 42 arranged on one or both sides of an anode current collector 46. The cathode electrode 20, the anode electrode 40, and the separator 32 are arranged in a predetermined order in the housing 50. For example, the separator 32 is arranged between the cathode electrode 20 and the anode electrode 40. The anode current collector 46 and / or the cathode current collector 26 include a wire mesh coated or coated and annealed as described below.
[0058] Reference now Figures 2A to 2B , the anode current collector and / or the cathode current collector comprises a wire mesh 70, which comprises a plurality of first wires 74 spaced at predetermined intervals and extending parallel to each other in a first direction. The wire mesh 70 comprises a plurality of second wires 76 spaced at certain intervals and extending parallel to each other in a second direction different from the first direction. The plurality of first wires 74 and the plurality of second wires 76 are interwoven up and down with each other. In some embodiments, the first direction and the second direction are transverse, although other angles may be used.
[0059] If not coated or not coated and annealed, the screen 70 exhibits anisotropy in its mechanical properties. Figure 2A When pulled in the direction of , the stiffness of the exemplary copper wire mesh is about 22N / mm and the peak load is about 8N. Figure 2B When pulled in the direction of the center, the stiffness is extremely low ~0.06 N / mm, and the peak load is about 1.5 to 2 N. In addition to the low stiffness, the electrical contact between the wire mesh wires at the mesh junctions varies with position. This in turn causes the resistance of the wire mesh current collector to vary.
[0060] The coating or coating and annealing of the wire mesh current collector as described herein improves the strength and rigidity of the wire mesh current collector. Therefore, the wire mesh current collector has improved manufacturability because they are easier to use due to the increased strength. The coated or coated and annealed wire mesh current collector also provides enhanced contact between the plurality of first wires and the plurality of second wires at the grid junction, which reduces resistance and improves the rate performance of the lithium metal anode (LMA). In addition, some coatings (such as In, Sn, Bi and Zn) are lithium-philic, which improves the attachment of lithium to the current collector surface.
[0061] Reference now Figure 3A and 3B , showing methods 100 and 100' of coating a wire mesh current collector 110. Figure 3A In some embodiments, the coating and / or annealing method is a continuous roll-to-roll method. The wire mesh current collector 110 is immersed in a bath 126 and a metal coating is deposited on the wire mesh current collector 110. In some embodiments, the bath includes a metal salt. In some embodiments, the wire mesh current collector 110 is chemically coated or electrochemically coated. In some embodiments, a negative current is applied to the wire mesh current collector 110 during the chemical coating process.
[0062] The wire mesh current collector 110 passes over roller 114, enters bath 126, and passes under roller 132 located in bath 126. In some embodiments, roller 114 is connected to a power source that supplies current, while roller 132 and / or bath 126 are grounded. After passing through bath 126, the coated wire mesh current collector 134 passes over roller 136 and under roller 138, and then passes through heater 144, which is configured to anneal the wire mesh current collector 110 at a temperature above the melting temperature of the metal used for coating. Although a specific arrangement of rollers is shown, the rollers can be arranged in other configurations.
[0063] exist Figure 3B In the process, discrete sections of the wire mesh current collector 110 are immersed in a bath 126 for a predetermined time to chemically coat, deposit, or electroplate a metal coating onto the wire mesh current collector 110. The discrete sections of the wire mesh current collector 110 may be optionally annealed by a heater after coating.
[0064] In some embodiments, the coated wire mesh current collector 134 is heated by a heater 144 at a predetermined temperature higher than the melting temperature of the metal coating to re-melt and flow the metal coating. The molten coating enters between the wires of the wire mesh under the action of capillary forces. The wire mesh is allowed to cool and the metal coating is re-solidified. The metal coating is re-solidified at the metal junctions to rigidly connect the plurality of first wires and the plurality of second wires at the mesh junctions. The rigid connection increases the physical strength of the wire mesh and reduces the internal resistance of the wire mesh.
[0065] In some embodiments, the coating has a thickness of 1 nm to 1 μm. In some embodiments, the heater 144 heats the coated wire mesh current collector for a predetermined time of 10 seconds to 30 minutes. In some embodiments, the heater heats the coated wire mesh current collector for a predetermined time of 1 minute to 10 minutes.
[0066] In some embodiments, the melting point of the metal in the coating is lower than the melting temperature of the material used for wire mesh current collector 110. In other embodiments, a coating material (e.g., Ni) with a higher melting temperature than the metal (e.g., Cu) used for the wires of the wire mesh current collector may be used and annealing omitted.
[0067] In some embodiments, the metal is selected from tin (Sn), indium (In), bismuth (Bi), nickel (Ni), zinc (Zn) and alloys thereof. In some embodiments, the coated wire mesh current collector 134 may be cooled before annealing to solidify the coating. In other embodiments, the coated wire mesh current collector 134 is not completely cooled after bath 126 and before annealing by heater 144.
[0068] Reference now Figure 4A and 4B, showing the wire mesh current collector 134 after applying a metal coating. The wire mesh current collector 134 includes a plurality of first wires 210 extending in a first direction and a plurality of second wires 212 extending in a second direction different from the first direction (e.g., transversely). The plurality of first wires 210 and the plurality of second wires 212 of the wire mesh current collector 134 include a coating 218.
[0069] Reference now Figure 5A and 5B , showing the wire mesh current collector 148 after coating and annealing. The wire mesh current collector 134 includes the plurality of first wires 210 extending in a first direction and the plurality of second wires 212 extending in a second direction different from the first direction (e.g., transverse). The plurality of first wires 210 and the plurality of second wires 212 of the wire mesh current collector 134 include a coating 218. After annealing, at least some of the coating remelts and is drawn between the plurality of first wires 210 and the plurality of second wires 212 by capillary forces as shown at 220.
[0070] The above description is only exemplary and is absolutely not intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in various forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be limited thereto, because after studying the drawings, the specification and the following claims, other modifications will become apparent. It should be understood that one or more steps in the method may be implemented in different orders (or simultaneously) without changing the principles of the present disclosure. In addition, although each embodiment is described above as having certain features, any one or more features described in any embodiment of the present disclosure may be implemented in any other embodiment and / or combined with the features of any other embodiment, even if the combination is not explicitly described. In other words, the embodiments are not mutually exclusive, and the mutual replacement of one or more embodiments is still within the scope of the present disclosure.
[0071] Various terms are used to describe the spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.), including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "on," "under," and "disposed." Unless explicitly described as "directly," when describing the relationship between a first element and a second element in the above disclosure, the relationship can be a direct relationship in which there are no other intervening elements between the first element and the second element, or an indirect relationship in which there are one or more intervening elements (spatially or functionally) between the first element and the second element. The phrase "at least one of A, B, and C" as used herein should be interpreted to mean a logical (A or B or C) using a non-exclusive logical OR, and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."
[0072] In the drawings, the direction of the arrows, as shown by the arrows, generally shows the flow of information (such as data or instructions) that the illustration is concerned with. For example, when component A and component B exchange various information but the information sent from component A to component B is relevant to the illustration, the arrow may point from component A to component B. Such a one-way arrow does not mean that no other information is sent from component B to component A. In addition, for information transmitted from component A to component B, component B may send a request for the information or a receipt to component A.
Claims
1. A method for manufacturing a current collector for an electrode of a battery cell, comprising: A wire mesh current collector is provided, which includes a plurality of first wires and a plurality of second wires stacked to form a plurality of grid joints. wherein the diameters of the plurality of first wires and the plurality of second wires are 4 μm to 100 μm; and The wire mesh current collector is coated with the metal coating by immersing it in a bath containing a metal salt. 2 . The method according to claim 1 , wherein the plurality of first wires and the plurality of second wires of the wire mesh current collector are made of one or more metals selected from copper, stainless steel, brass, bronze, zinc, aluminum and alloys thereof.
3. The method of claim 1, wherein the metal coating comprises a metal selected from the group consisting of indium (In), tin (Sn), bismuth (Bi), zinc (Zn), nickel (Ni), and alloys thereof. 4 . The method of claim 1 , further comprising annealing the wire mesh current collector after coating the wire mesh current collector to enhance physical and electrical contact at the plurality of mesh junctions. 5 . The method of claim 4 , wherein the annealing is performed at a temperature higher than a melting temperature of a metal of the metal coating and lower than a melting temperature of a metal of the plurality of first wires and the plurality of second wires of the wire mesh current collector. The method of claim 1 , further comprising disposing a layer of an anodically active material adjacent to the wire mesh current collector.
7. The method of claim 1, further comprising disposing a cathode active material layer adjacent to the wire mesh current collector.
8. The method of claim 1, further comprising coating the wire mesh current collector with a slurry comprising an anode active material.
9. The method of claim 1, further comprising coating the wire mesh current collector with a slurry comprising a cathode active material.
10. The method of claim 1, wherein the wire mesh current collector is immersed in a bath in discrete sections.