Resin layers of a solid-state battery with anode overhang

Abstract

A solid-state battery with a specific structure and methods for forming the same are discussed. The solid-state battery comprises a compact solid-state battery cell including a separator-anode laminate, a plurality of solid resin layers defining a frame located around and extending from a perimeter of a separator side of the separator-anode laminate, and a cathode disposed within the frame and in direct contact with the separator side such that adjacent outer surfaces of the frame and the cathode are flush.

Description

FIELD OF TECHNOLOGYThis disclosure relates to a cell structure for lithium ion battery cells.GENERAL STATE OF THE ARTIn solid state batteries, applying pressure to individual layers of the battery may help increase their interlayer contact and conductivity, which may result in better battery performance.SUMMARYIn one aspect, an all-solid-state battery comprises a compact all-solid-state battery cell including a separator anode laminate, a plurality of solid resin layers defining a frame disposed around and extending from a periphery of a separator side of the separator anode laminate, and a cathode disposed within the frame and in direct contact with the separator side such that adjacent outer surfaces of the frame and the cathode are flush.The all-solid-state battery may further include an electrical tab attached to an anode side of the separator-anode laminate. A separator portion of the separator-anode laminate may be sulfide-based. A separator portion of the separator-anode laminate may be based on silicon. The thickness of the cathode may be less than 40 μm. A modulus of elasticity of the solid resin layers may be within 10% of a modulus of elasticity of the cathode.In another aspect, a lithium ion battery includes a cathode, a separator laminated with an anode, and a solid resin frame printed on the separator and overlapped by the anode, such that the cathode can be placed inside the solid resin frame and compressed with the separator, the anode, and the solid resin layer to form a battery cell. The battery cell may further include an electrical tab connected to the anode and extending from a side opposite the separator. The solid frame may have a modulus of elasticity that is within 10% of that of the cathode. The solid resin layer may have either a thickness greater than a thickness of the cathode or a thickness less than the thickness of the cathode. The solid resin layer may be made of a thermosetting material. The separator may be based on porous polyethylene. In other configurations, the separator may be sulfide based and the anode may be silicon composite based.In another aspect, a method includes printing a solid resin frame around a perimeter of a separator side of a separator-anode laminate. arranging a cathode on the separator side and inside the solid resin frame and compressing the solid resin frame, the separator anode laminate, and the cathode such that adjacent outer surfaces of the solid resin frame and the cathode are flush to form a compact lithium ion battery cell. In some configurations, at least 400 megapascals (MPa) may be applied during the compression step.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1A is a top view of a cathode-sized mask on an anode, according to an embodiment; FIG. 1B is a plan view of a cathode-sized mask on a separator side of a separator-anode laminate according to an embodiment; FIG. 1C is a plan view of a plurality of resin layers on an assembly according to an embodiment; FIG. 1D is a top view of a cathode including an assembly according to an embodiment; FIG. 1E is a schematic cross-sectional view of the assembly of FIG. 1D along line V-V, according to an embodiment; FIG. 1F is a schematic cross-sectional view of the compact assembly of FIG. 1D along line V-V after the compressing step, according to an embodiment; and FIG. 2 is a flow diagram of an assembly process according to an embodiment.DETAILED DESCRIPTIONEmbodiments are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. The figures are not necessarily to scale. Some features could be exaggerated or minimized to show details of specific components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art.Various features illustrated and described with respect to any of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not expressly illustrated or described. The illustrated combinations of features provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of this disclosure could be desired for specific applications or implementations.Solid state batteries in an anode overhang configuration where the cathode is smaller in dimension than the combined separator-anode laminate may have cracks on the solid state separator, particularly around the edge of the cathode after application of pressure. These cracks may be caused by the accumulation of stress at these points.The proposed assembly process includes printing a solid resin around a cathode. This step is intended to distribute pressure more evenly during the compression phase. By selecting a resin having similar properties, such as a modulus of elasticity, to the cathode, the edge of the cathode is less likely to become a primary pressure point, which may help mitigate cracking. Even if the resin is not flush with the cathode, the presence of the resin adjacent the cathode edge may help maintain a gap between the compressed cathode and an uncompressed anode. This spacing may reduce the likelihood of a short circuit.FIG. 1A illustrates a top view of a cathode-sized mask 12 on an anode 10, FIG. 1B illustrates a top view of a cathode-sized mask 12 on a separator side 14 of a separator-anode laminate 16, according to an embodiment. The separator-anode laminate 16 may have various material compositions including, but not limited to, a sulfide-based separator portion 14 and an anode portion 10 that may be silicon-based, thereby providing increased ionic conductivity or energy capacity. In some configurations, the separator portion 14 may be porous polyethylene. FIG. 1C shows a top view of a plurality of resin layers 20 on the separator side 14 of the separator-anode laminate 16 with an electrical tab 18. the electrical tab 18 may be attached to the anode side 10 of the separator-anode laminate 16 and extend from a side opposite the separator 14 to facilitate external electrical connection. The solid resin layers 20 may be printed on the inside of the cathode-sized mask 12 in such a manner as to form a solid resin frame 20. The frame 20 may extend away from a periphery of the separator side 14 to receive a cathode. After the frame 20 is formed, the cathode-sized mask 12 may be removed.FIG. 1D illustrates a plan view of a cathode 22 placed inside the resin frame 20 constituting the battery cell 24. The cathode 22 is disposed within the frame 20 in direct contact with the separator side 14 of the separator-anode laminate 16. The material selected for the solid resin layer 20 may be a thermosetting material. In addition, the resin 20 may have an elastic modulus that is within 10% of that of the cathode 22. In other configurations, the resin 20 may have a modulus of elasticity greater than the modulus of elasticity of the cathode 22. FIG. 1E illustrates a cross-sectional view of the lithium-ion battery cell 24 of FIG. 1D along line V-V. FIG. 1F is a schematic cross-sectional view of the lithium-ion battery cell 24 of FIG. 1D along line V-V after the step of compressing. During the compressing step, the cathode 22, the separator-anode laminate 16, and the solid resin frame 20 are compressed, which may increase the interfacial contact and overall integrity of the battery cell 24. After the step of compressing, the cathode may have a thickness of less than 40 μm. The adjacent outer surfaces of the frame 20 and the cathode 22 may be flush. In some configurations, the thickness of the solid resin frame 20 may be within, greater than, or less than 10% of the thickness of the cathode 22.FIG. 2 shows a flow diagram of an assembly process according to an embodiment. Beginning with block one 26, a solid resin frame is printed around a perimeter of a separator side of a separator-anode laminate. The separator may be based on porous polyethylene. In other configurations, the separator may be sulfide based and the anode may be silicon composite based. An electrical tab may be attached to an anode side of the separator-anode laminate. The printing process may employ techniques such as 3D printing or screen printing. At block two 28, a cathode is disposed on the separator side and within the solid resin frame. The materials used for the solid resin may have a modulus of elasticity that is within 10% of a modulus of elasticity of the cathode. At block three 30, the solid resin frame, the separator anode laminate, and the cathode are compressed such that adjacent outer surfaces of the solid resin frame and the cathode are flush to form a compact lithium-ion battery cell. The step of compressing block three 30 may comprise a pressure to be applied of at least 400 MPa.The algorithms, methods, or processes disclosed or proposed herein may be executable or implemented by a computer, controller, or processing device, which may include any dedicated electronic control unit or programmable electronic control unit. Likewise, the algorithms, methods, or processes may be stored in many forms as computer or controller executable data and instructions, including, without limitation, information permanently stored on non-writable storage media such as read-only memory devices and information alterably stored on writeable media such as compact discs, random access memory devices, or other magnetic and optical media. The algorithms, methods, or processes may also be implemented in software executable objects. Alternatively, the algorithms, methods, or processes may be implemented in whole or in part using suitable hardware components, such as application specific integrated circuits, field programmable gate arrays, state machines, or other hardware components or devices, or a combination of firmware, hardware, and software components.While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms covered by the claims. The terms 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 these disclosed subject matters.As described above, the features of various embodiments may be combined to form further embodiments of the disclosure that may not be expressly described or illustrated. While various embodiments could have been described as providing or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art will understand that one / more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to, strength, durability, market capacity, appearance, packaging, size, maintenance capacity, weight, matable, ease of assembly, etc. Thus, embodiments 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 particular applications.According to the present invention, there is provided an all-solid-state battery comprising: a compact all-solid-state battery cell including a separator anode laminate, a plurality of solid resin layers defining a frame located around and extending from a periphery of a separator side of the separator anode laminate, and a cathode disposed within the frame and in direct contact with the separator side such that adjacent outer surfaces of the frame and the cathode are flush.According to one embodiment, the invention is further characterized by an electrical tab attached to an anode side of the separator-anode laminate.According to an embodiment, a separator portion of the separator anode laminate is based on sulfide.According to an embodiment, an anode portion of the separator-anode laminate is based on silicon.According to an embodiment, a thickness of the cathode is less than 40 μm.According to an embodiment, a modulus of elasticity of the solid resin layers is within 10% of a modulus of elasticity of the cathode.According to the present invention, there is provided a lithium ion battery including: a cathode; a separator and an anode stacked together; and a solid resin frame printed on the separator and overlapped by the anode, such that the cathode can be placed inside the solid resin frame and compressed with the separator, the anode, and the solid resin frame to form a battery cell.According to an embodiment, the invention is further characterized by an electrical tab connected to the anode and extending from a side opposite to the separator.According to an embodiment, the solid resin frame has a modulus of elasticity within 10% of the modulus of elasticity of the cathode.According to an embodiment, the solid resin frame has a modulus of elasticity that is greater than the modulus of elasticity of the cathode.According to an embodiment, the solid resin frame has a modulus of elasticity that is smaller than the modulus of elasticity of the cathode.According to an embodiment, the solid resin frame has a thickness within 10% of a thickness of the cathode.According to an embodiment, the solid resin frame has a thickness that is greater than a thickness of the cathode.According to an embodiment, the solid resin frame has a thickness that is smaller than a thickness of the cathode.According to one embodiment, the solid resin frame is made of a thermosetting material.According to one embodiment, the separator is based on porous polyethylene.According to one embodiment, the separator is based on sulfide.According to one embodiment, the anode is based on silicon composite.According to the present invention, a method includes: printing a solid resin frame around a periphery of a separator side of a separator anode laminate; disposing a cathode on the separator side and within the solid resin frame; and compressing the solid resin frame, the separator anode laminate, and the cathode such that adjacent outer surfaces of the solid resin frame and the cathode are flush to form a compact lithium ion battery cell.In one aspect of the invention, at least 400 MPa is applied during compression of the solid resin frame, the separator anode laminate, and the cathode.

Claims

An all-solid-state battery comprising: a compact all-solid-state battery cell including a separator anode laminate, a plurality of solid resin layers defining a frame located around and extending from a periphery of a separator side of the separator anode laminate, and a cathode disposed within the frame and in direct contact with the separator side such that adjacent outer surfaces of the frame and the cathode are flush.The all-solid-state battery of claim 1, further comprising an electrical tab attached to an anode side of the separator-anode laminate.The all-solid-state battery of claim 1, wherein a separator portion of the separator-anode laminate is sulfide-based.The all-solid-state battery of claim 1, wherein an anode portion of the separator-anode laminate is silicon-based.The all solid state battery of claim 1, wherein a thickness of the cathode is less than 40 μm.The all-solid-state battery according to claim 1, wherein a modulus of elasticity of the solid resin layers is within 10% of a modulus of elasticity of the cathode.A lithium ion battery comprising: a cathode; a separator and an anode stacked together; and a solid resin frame printed on the separator and overlapped by the anode, such that the cathode can be placed inside the solid resin frame and compressed with the separator, the anode, and the solid resin frame to form a battery cell.The lithium ion battery of claim 7, further comprising an electrical tab connected to the anode and extending from a side opposite the separator.The lithium ion battery of claim 7, wherein the solid resin frame has a modulus of elasticity that is within 10% of the modulus of elasticity of the cathode.The lithium ion battery according to claim 7, wherein the solid resin frame has a modulus of elasticity greater than the modulus of elasticity of the cathode.The lithium ion battery according to claim 7, wherein the solid resin frame has a modulus of elasticity smaller than the modulus of elasticity of the cathode.The lithium ion battery of claim 7, wherein the solid resin frame has a thickness that is within 10% of a thickness of the cathode.The lithium ion battery of claim 7, wherein the solid resin frame has a thickness greater than a thickness of the cathode.A method comprising: printing a solid resin frame around a periphery of a separator side of a separator anode laminate; disposing a cathode on the separator side and within the solid resin frame; and compressing the solid resin frame, the separator anode laminate, and the cathode such that adjacent outer surfaces of the solid resin frame and the cathode are flush to form a compact lithium ion battery cell.The method of claim 14, wherein at least 400 MPa is applied during compression of the solid resin frame, the separator-anode laminate, and the cathode.

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