Solid state battery cell fabrication

Abstract

The invention provides solid state battery cell fabrication. A method includes disposing a double-sided positive electrode assembly between a pair of single-sided negative electrode assemblies such that a positive electrode coating of the double-sided positive electrode assembly directly contacts a solid electrolyte separator layer of the single-sided negative electrode assembly to form a solid state electrode assembly; and applying pressure to each of the single-sided negative electrode assemblies to compress the solid state electrode assemblies and establish ionic contact between the positive electrode coating and the solid electrolyte separator layer.

Description

Technical Field

[0001] The present disclosure relates to battery manufacturing technology. Background Art

[0002] Solid-state batteries are energy storage devices that differ from traditional lithium-ion batteries, which use liquid electrolytes. Solid-state batteries use solid electrolytes, usually ceramic or solid polymers, to conduct ions between the positive and negative electrodes of the battery. Summary of the invention

[0003] A method for manufacturing a solid-state battery cell includes arranging a double-sided positive electrode assembly between a pair of single-sided negative electrode assemblies so that the positive electrode coating of the double-sided positive electrode assembly directly contacts the solid electrolyte separator layer of the single-sided negative electrode assembly to form a solid-state electrode assembly; and applying pressure to each of the single-sided negative electrode assemblies to compress the solid-state electrode assembly and establish ionic contact between the positive electrode coating and the solid electrolyte separator layer to form a solid-state battery cell, wherein the collector of the single-sided negative electrode assembly defines the outer surface of the solid-state battery cell.

[0004] A method for manufacturing multiple solid-state battery cells includes: arranging a double-sided positive electrode assembly defining multiple positive electrode tabs between a pair of single-sided negative electrode assemblies defining multiple negative electrode tabs, so that the positive electrode coating of the double-sided positive electrode assembly directly contacts the solid electrolyte separator layer of the single-sided negative electrode assembly to form a solid electrode assembly; applying pressure to each of the single-sided negative electrode assemblies to compress the solid electrode assembly and establish ionic contact between the positive electrode coating and the solid electrolyte separator layer to form an extended solid-state battery preform; and cutting the extended solid-state battery preform to form multiple solid-state battery cells so that each of the multiple solid-state battery cells has one of the positive electrode tabs and one of the negative electrode tabs.

[0005] A method for manufacturing multiple solid-state battery cells includes: arranging a double-sided positive electrode assembly defining multiple positive electrode tabs between a pair of single-sided negative electrode assemblies defining multiple negative electrode tabs, so that the positive electrode coating of the double-sided positive electrode assembly directly contacts the solid electrolyte separator layer of the single-sided negative electrode assembly to form a solid electrode assembly; applying pressure to each of the single-sided negative electrode assemblies to compress the solid electrode assembly and establish ionic contact between the positive electrode coating and the solid electrolyte separator layer to form an extended solid-state battery preform; and winding the extended solid-state battery preform to form a wound battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figures 1 to 4 Shown is the cell design and process using a one-step multilayer calendering process.

[0007] Figures 5 to 7 Shown with Figures 1 to 4 A similar one-step calendering process is shown.

[0008] Figures 8 to 14 Another method for manufacturing solid-state battery cells is shown. DETAILED DESCRIPTION

[0009] As required, detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely examples of the present invention that can be implemented in various forms and alternative forms. The drawings are not necessarily drawn to scale; some features may be enlarged or minimized to show details of specific components. Therefore, the specific structural details and functional details disclosed herein are not to be interpreted as limiting, but only as a representative basis for teaching those skilled in the art to adopt the present invention in various ways.

[0010] The typical lithium-ion battery process involves coating the electrode layers, stacking or winding the electrodes with an insulating separator, and then filling them with a liquid electrolyte. An alternative is to use a solid electrolyte in a solid-state battery.

[0011] Solid-state batteries can potentially provide electric vehicle battery solutions with higher energy density compared to conventional lithium-ion batteries. When a solid electrolyte is placed between the anode and cathode, it can physically separate the electrodes, which can eliminate the need for separators and subsequent electrolyte filling steps. However, electrolytes in solid form face challenges in terms of contact resistance with the solid particles around them that complete the space between the filling active materials. Traditional solid-state battery assemblies require high area pressure or isostatic pressure to laminate multiple electrodes and separators together. In order to achieve higher capacity for the production of solid-state batteries, alternative manufacturing processes may be required.

[0012] Here, a solid-state battery cell design is proposed that can be manufactured in a process similar to that of lithium-ion batteries while reducing the contact resistance between solid particles. Specifically, this approach can utilize high line pressure and roll-to-roll processing during calendaring to minimize the interface resistance between the electrode and the solid electrolyte separator layer.

[0013] In some lithium-ion battery designs, both the cathode and the anode are double-sided coated on the current collector. In one proposed design, one electrode is single-sided coated, while the counter electrode is double-sided coated. The calendering step is used to press the two single-sided coated electrodes and the double-sided coated electrode together and remove pores and gaps in and between the electrodes. Prior to the calendering step, at least one of the electrodes may need to be laminated with a solid electrolyte layer. In the previous step, the electrodes may be additionally calendered or not calendered.

[0014] Anode and cathode electrode rolls with or without solid electrolyte separator laminations may be slotted or cut to a specific size. Three layers including two single coatings and one double coating may be fed into a calender at room temperature or elevated temperature and pressed together by calender rollers to form an ABA unit layer. The high line pressure of the calender applied continuously to the rolling electrode allows the removal of gaps and pores within the ABA unit layer, thereby reducing the contact resistance within the unit. The ABA unit layer may then be wound or stacked into multiple unit layers.

[0015] The proposed method can be applied to solid-state battery cells with anodes, cathodes and separators of the same size. The reason is that in lithium-ion battery cells, the overhang of the anode can help prevent short circuits caused by the presence of ion-conducting electrolyte in areas outside the electrode edge (resulting in possible excessive deposition of lithium), while in solid-state batteries, the ion paths are only limited in the presence of solid electrolytes. By making all three layers of the cell identical, there are no ion-conducting paths outside the direct contact areas between the anode, separator and cathode, and there can be no local oversupply of lithium. As an example, two layers of anode laminated with separators and one layer of double-sided coated cathode of the same size can be calendered together and then cut to make individual units.

[0016] A possible advantage of having an overhang is to reduce the possibility of short circuits at the electrode edges. The coating layer can first be slotted to form tabs during calendering, and then the three layers are pressed into a unit layer and cut into individual units. Patterned coatings on double-sided coating layers can be used to allow overhang designs. Alternatively, the coating layer can be slotted and cut into individual electrode sizes, which are then pressed into a unit layer. The individual units are then stacked together to form a battery cell with multiple stacks.

[0017] In another example, both electrodes can be coated and grooved continuously before the multilayer calendering step. After being pressed into unit layers, the unit layers can be wound to form prismatic cells or cylindrical cells. Because only metal-to-metal contact is involved in the stacking or winding process, high voltage is not required to form a solid electrolyte interface. In addition, compared with alternative stacking of electrodes in some soft-pack battery cell designs, a unit stacking process eliminates the need for high-precision alignment during the stacking process and can significantly reduce processing time. The process can also allow continuous calendering, cutting and stacking.

[0018] Figures 1 to 4 Shown is the cell design and process using a one-step multilayer calendering process. Figures 1 to 4A double-sided positive electrode assembly 22 and a pair of single-sided negative electrode assemblies 24 are shown. The double-sided positive electrode assembly 22 is composed of a cathode coating 38 and a cathode current collector 40. The double-sided positive electrode assembly 22 includes two layers of cathode coating 38, wherein the cathode current collector 40 is between the cathode coatings 38. The double-sided positive electrode assembly 22 also defines a positive tab 36. The single-sided negative electrode assembly 24 is composed of a positive coating 26, a solid electrolyte 28, and an anode current collector 30. In the single-sided negative electrode assembly 24, the positive coating 26 is placed between the solid electrolyte layer 28 and the anode current collector 30. The single-sided negative electrode assembly 24 also defines a negative tab 34. According to one embodiment, at the interface of the double-sided positive electrode assembly 22 and the single-sided negative electrode assembly 24, the surface areas of the electrode assemblies 22, 24 are the same. According to another embodiment, at the interface of the double-sided positive electrode assembly 22 and the single-sided negative electrode assembly 24, the surface areas of the electrode assemblies 22, 24 are different.

[0019] refer to Figure 1 The double-sided positive electrode assembly 22 is arranged between the pair of single-sided negative electrode assemblies 24 so that the solid electrolyte layer 28 is in direct contact with the cathode coating 38 of the double-sided positive electrode assembly 22 to form a solid electrode assembly 21.

[0020] refer to Figure 2 and Figure 3 , pressure is applied to each of the single-sided negative electrode assemblies 24 to compress the solid-state electrode assembly 21 and establish ionic contact between the positive electrode coating 26 and the solid electrolyte separator layer 28 to form a solid-state battery cell 20. The pressure applied to each of the single-sided negative electrode assemblies 24 is a calendering step in the process for forming the solid-state battery cell 20. Applying pressure to the single-sided negative electrode assembly 24 removes pores and gaps in and between any layers of the solid-state electrode assembly 21. The anode current collector 30 of the single-sided negative electrode assembly 24 defines the outer surface of the solid-state battery cell 20. According to one embodiment, when the surface areas of the double-sided positive electrode assembly 22 and the single-sided negative electrode assembly 24 are different, the single-sided negative electrode assembly 24 is overhung over the double-sided positive electrode assembly 22. In the solid-state battery cell 20, the overhang of the single-sided negative electrode assembly 24 can help prevent short circuits caused by the presence of ion-conducting electrolytes in areas outside the electrode edges (which may cause lithium ions to be excessively deposited). Figure 4 Shown in Figures 1 to 3 The finished solid-state battery cell 20 after the calendering process is shown in FIG.

[0021] Figures 5 to 7 Shown with Figures 1 to 4 A similar one-step calendering process as shown, but Figures 5 to 8 A process is shown where the double-sided positive electrode assembly 22 and the single-sided negative electrode assembly 24 are of the same size. Figure 5The double-sided positive electrode assembly 22 is shown arranged between a pair of single-sided negative electrode assemblies 24. The double-sided positive electrode assembly 22 defines a positive tab 36, and the single-sided negative electrode assembly 24 defines a negative tab 34. The positive electrode coating 26 of the double-sided positive electrode assembly 22 directly contacts the solid electrolyte separator layer 28 of the single-sided negative electrode assembly 24 to form a solid electrode assembly 21. Once the electrode assemblies 22, 24 are arranged, pressure is applied to each of the single-sided negative electrode assemblies 24 to compress the solid electrode assembly 21. Applying pressure to compress the solid electrode assembly 21 establishes ionic contact between the positive electrode coating 26 and the solid electrolyte separator layer 28 to form Figure 6 An expanded solid-state battery preform 32 is shown in FIG. Figure 6 Also shown is cutting of the expanded solid-state battery preform 32 to form a plurality of solid-state battery cells 20 , such that each of the plurality of cells 20 has one of the positive tabs 36 and one of the negative tabs 34 .

[0022] Continue to refer Figures 5 to 7 In one embodiment, the interface of the double-sided positive electrode assembly 22 and the single-sided negative electrode assembly 24 has a surface area that is the same for each of the solid-state battery cells 20. In another embodiment, the interface of the double-sided positive electrode assembly 22 and the single-sided negative electrode assembly 24 has a surface area that is different for each of the solid-state battery cells 20. In the embodiment where the surface area is different for each of the solid-state battery cells 20, the single-sided negative electrode assembly 24 is suspended above the double-sided positive electrode assembly 22.

[0023] Figures 8 to 14 Another method for manufacturing a solid-state battery cell 20 having an arranging step, a pressurizing step, and a winding step is shown. Figure 8 The double-sided positive electrode assembly 22 is shown arranged between a pair of single-sided negative electrode assemblies 24. The double-sided positive electrode assembly 22 defines a plurality of positive tabs 36, and the single-sided negative electrode assembly 24 defines a plurality of negative tabs 34. The positive electrode coating 26 of the double-sided positive electrode assembly 22 directly contacts the solid electrolyte separator layer 28 of the single-sided negative electrode assembly 24 to form the solid electrode assembly 21. Once the electrode assemblies 22, 24 are arranged, pressure (not shown) is applied to each of the single-sided negative electrode assemblies 24. The pressure compresses the solid electrode assembly 21 and establishes ionic contact between the positive electrode coating 26 and the solid electrolyte separator layer 28 to form Fig. 9 The expanded solid-state battery preform 32 shown in FIG. The expanded solid-state battery preform 32 is then wound to form a wound battery cell. The wound battery cell may be a wound cylindrical cell or a wound prismatic cell.

[0024] Figures 8 to 92 shows an embodiment in which the electrode assemblies 22, 24 are grooved to form the negative tab 34 and the positive tab 36 prior to the calendaring / pressing step. According to another embodiment, as Figures 10 to 12 As shown, the electrode assemblies 22 , 24 may be slotted and cut into individual electrode cells and then calendared / pressed into an expanded solid-state battery preform 32 . Figure 13 to Figure 14 The electrode assemblies 22, 24 are shown being successively coated and grooved prior to the multi-layer calendaring step. During the winding process, only metal-to-metal contact is involved, so high pressure is not required to form a solid electrolyte interface.

[0025] The algorithm, method or process disclosed herein can be delivered to or implemented by a computer, controller or processing device, which can include any dedicated electronic control unit or programmable electronic control unit. Similarly, the algorithm, method or process can be stored in various forms as data and instructions that can be executed by a computer or controller, including but not limited to information permanently stored on a non-writable storage medium such as a read-only memory device and information that can be modified and stored on a writable storage medium such as an optical disk, a random access memory device or other magnetic and optical media. The algorithm, method or process can also be implemented by a software executable object. Alternatively, a suitable hardware component (such as an application-specific integrated circuit, a field programmable gate array, a state machine or other hardware component or device) or a combination of firmware, hardware and software components can be used to embody the algorithm, method or process in whole or in part.

[0026] Although 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 should be understood that various changes can be made without departing from the spirit and scope of these disclosed materials.

[0027] As previously mentioned, the features of the various embodiments may be combined to form additional embodiments of the present 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 appreciated 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. Therefore, embodiments that are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are within the scope of the present disclosure and may be desirable for a particular application.

Claims

1. A method for manufacturing a solid-state battery cell, the method comprising: Disposing a double-sided positive electrode assembly between a pair of single-sided negative electrode assemblies such that the positive electrode coating of the double-sided positive electrode assembly directly contacts the solid electrolyte separator layer of the single-sided negative electrode assembly to form a solid electrode assembly; as well as Pressure is applied to each of the single-sided negative electrode assemblies to compress the solid-state electrode assembly and establish ionic contact between the positive electrode coating and the solid electrolyte separator layer to form a solid-state battery cell, wherein the collector of the single-sided negative electrode assembly defines an outer surface of the solid-state battery cell.

2. The method of claim 1, wherein the double-sided negative electrode assembly defines a positive tab, and wherein each of the single-sided negative electrode assemblies defines a negative tab.

3. The method of claim 1, wherein at the interface of the double-sided positive electrode assembly and the single-sided negative electrode assembly, the surface areas of the double-sided positive electrode assembly and the single-sided negative electrode assembly are the same.

4. The method of claim 1, wherein at the interface of the double-sided positive electrode assembly and the single-sided negative electrode assembly, the surface areas of the double-sided positive electrode assembly and the single-sided negative electrode assembly are different.

5. The method of claim 4, wherein the surface areas are different such that the single-sided negative electrode assembly overhangs the double-sided positive electrode assembly.

6. A method for manufacturing a plurality of solid-state battery cells, the method comprising: disposing a double-sided positive electrode assembly defining a plurality of positive electrode tabs between a pair of single-sided negative electrode assemblies defining a plurality of negative electrode tabs such that the positive electrode coating of the double-sided positive electrode assembly directly contacts the solid electrolyte separator layer of the single-sided negative electrode assembly to form a solid electrode assembly; applying pressure to each of the single-sided negative electrode assemblies to compress the solid electrode assembly and establish ionic contact between the positive electrode coating and the solid electrolyte separator layer to form an extended solid-state battery preform; as well as The expanded solid-state battery preform is cut to form a plurality of solid-state battery cells, such that each of the plurality of solid-state battery cells has one of the positive electrode tabs and one of the negative electrode tabs.

7. The method of claim 6, wherein at the interface of the double-sided positive electrode assembly and the single-sided negative electrode assembly, the surface area of ​​the double-sided positive electrode assembly and the single-sided negative electrode assembly are the same for each of the solid-state battery cells.

8. The method of claim 6, wherein at the interface of the double-sided positive electrode assembly and the single-sided negative electrode assembly, the surface area of ​​the double-sided positive electrode assembly and the single-sided negative electrode assembly is different for each of the solid-state battery cells.

9. The method of claim 8, wherein the surface areas are different such that for each of the solid-state battery cells, the single-sided negative electrode assembly overhangs the double-sided positive electrode assembly.

10. A method for manufacturing a plurality of solid-state battery cells, the method comprising: disposing a double-sided positive electrode assembly defining a plurality of positive electrode tabs between a pair of single-sided negative electrode assemblies defining a plurality of negative electrode tabs such that the positive electrode coating of the double-sided positive electrode assembly directly contacts the solid electrolyte separator layer of the single-sided negative electrode assembly to form a solid electrode assembly; applying pressure to each of the single-sided negative electrode assemblies to compress the solid electrode assembly and establish ionic contact between the positive electrode coating and the solid electrolyte separator layer to form an extended solid-state battery preform; as well as The expanded solid-state battery preform is wound to form a wound battery cell.

11. The method of claim 10, wherein at the interface of the double-sided positive electrode assembly and the single-sided negative electrode assembly, the surface area of ​​the double-sided positive electrode assembly and the single-sided negative electrode assembly is the same for each of the solid-state battery cells.

12. The method of claim 10, wherein at the interface of the double-sided positive electrode assembly and the single-sided negative electrode assembly, the surface area of ​​the double-sided positive electrode assembly and the single-sided negative electrode assembly is different for each of the solid-state battery cells.

13. The method of claim 12, wherein the surface areas are different such that for each of the solid-state battery cells, the single-sided negative electrode assembly overhangs the double-sided positive electrode assembly.

14. The method of claim 10, wherein the wound battery cell is a wound cylindrical battery cell.

15. The method of claim 10, wherein the wound battery cell is a wound prismatic battery cell.

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