A solid-state battery

Abstract

The utility model relates to a solid-state battery, including a battery cell, an upper cover and a lower cover, wherein the battery cell is arranged between the upper cover and the lower cover, and both the upper cover and the lower cover are U-shaped structures, wherein the upper cover is arranged above the lower cover, and a protrusion is arranged at the lower end of the upper cover, and the protrusion extends toward the center line direction of the solid-state battery; grooves are provided on the outer walls on both sides of the lower cover, and the protrusion extends into the grooves, and the width of the groove in the vertical direction is greater than the width of the protrusion in the vertical direction. The outer shell of the solid-state battery is arranged as two upper and lower U-shaped structures, the protrusion is arranged on the upper cover, and the groove is arranged on the lower cover, for assembling the solid-state battery, and the size of the groove is greater than the size of the protrusion, so as to absorb the thickness reduction caused by the compression of the battery cell.

Description

Technical Field

[0001] The utility model relates to the technical field of solid-state batteries, in particular to a solid-state battery. Background Art

[0002] Solid-state batteries are batteries that use solid electrodes and solid electrolytes. They abandon the liquid electrolytes used in traditional lithium-ion batteries and use solid electrolytes instead. Solid-state batteries have advantages including high safety, high energy density, long cycle life, fast charging, and a wide operating temperature range. However, solid-state batteries also have problems such as high impedance and high cost. In order to ensure the reliable operation and low resistivity of the cells in solid-state batteries, hundreds of megawatts of compression force are required during the assembly process, which will reduce the thickness of the cells.

[0003] The shell of an existing solid-state battery includes two L-shaped packaging shells, and two end plates are arranged to surround the battery cell. The two L-shaped packaging shells and the two end plates are fixed by welding. When assembling the solid-state battery, this type of shell cannot absorb the thickness reduction caused by the compression of the battery cell, and it is difficult to ensure the reliable operation of the battery cell. Utility Model Content

[0004] In order to solve the technical problem that the solid-state battery cannot absorb the thickness reduction caused by the compression of the battery core, the utility model provides a solid-state battery.

[0005] To achieve the above-mentioned purpose, the utility model provides a solid-state battery, including a battery cell, an upper cover and a lower cover, the battery cell is arranged between the upper cover and the lower cover, the upper cover and the lower cover are both U-shaped structures, the upper cover is arranged above the lower cover, and a protrusion is arranged at the lower end of the upper cover, and the protrusion extends toward the center line direction of the solid-state battery; grooves are opened on the outer walls on both sides of the lower cover, the protrusion extends into the grooves, and the width of the grooves in the vertical direction is greater than the width of the protrusion in the vertical direction.

[0006] Furthermore, the end of the protrusion extends upward to form a barb structure.

[0007] Furthermore, the upper end of the groove extends upward and enters the interior of the lower cover, and the upper end structure of the groove cooperates with the barb structure.

[0008] Furthermore, an inclined surface is provided at the lower end of the groove, and the inclined surface extends from the bottom of the groove to the outer wall of the lower cover, and the height of the inclined surface on the bottom side of the groove is higher than the height of the inclined surface on the outer wall side of the lower cover.

[0009] Furthermore, the upper cover and the lower cover include a metal plate and an extension plate, the length of the extension plate is greater than the length of both sides of the U-shaped structure of the metal plate, the upper and lower sides of the battery cell are in contact with the metal plate, and the side walls of the battery cell are in contact with the extension plate.

[0010] Furthermore, the metal plate of the upper cover is an aluminum plate, the metal plate of the lower cover is a copper plate, the extension plate wrapping the aluminum plate is a first extension plate, and the extension plate wrapping the copper plate is a second extension plate.

[0011] Further, the protrusion is arranged at the end of the first extension plate, and the groove is arranged on the outer wall of the second extension plate.

[0012] Furthermore, the extension plate is made of elastic insulating material.

[0013] Furthermore, holes are drilled at the bending positions of the metal plate U-shaped structure, and the extension plates are wrapped around both sides of the metal plate U-shaped structure by injection molding.

[0014] Furthermore, it also includes soft insulating glue, and the soft insulating glue is distributed on at least two side surfaces of the battery core not covered by the upper cover and the lower cover.

[0015] The above technical solution of the utility model has the following advantages compared with the prior art:

[0016] (1) The outer shell of the solid-state battery is set as two upper and lower U-shaped structures, a protrusion is set on the upper cover, and a groove is set on the lower cover for assembling the solid-state battery, and the size of the groove is larger than the size of the protrusion to absorb the thickness reduction caused by the compression of the battery cell;

[0017] (2) The end of the protrusion of the upper cover extends upward to form a hook, and the upper end of the groove cooperates with the end structure of the protrusion to ensure that the lower cover clamps the upper cover. In addition, an inclined surface is provided at the lower end of the groove, so that when the thickness of the battery decreases due to the pressing force, the protrusion can continue to move downward along the inclined portion of the groove to avoid damage to the protrusion caused by the pressing force;

[0018] (3) The electrode unit is a copper-aluminum composite structure, with one side being aluminum and the other side being copper. The aluminum surface is connected to the positive electrode material, and the copper surface is connected to the negative electrode material. The upper cover is configured as a composite structure of an aluminum plate and plastic, and the lower cover is configured as a composite structure of a copper plate and plastic, wherein the aluminum plate is used as the positive electrode and the copper plate is used as the negative electrode. The plastic is used as an insulating plate to isolate the electrode unit inside the battery cell from direct contact with the copper plate and the aluminum plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a structural schematic diagram of a solid-state battery of the utility model;

[0021] Figure 2 This is a schematic diagram of the structure of a battery cell in a solid-state battery of the utility model;

[0022] Figure 3 It is a structural side view of the solid-state battery of the utility model.

[0023] Explanation of the reference numerals in the accompanying drawings in the specification: upper cover-1; protrusion-11; battery cell-2; lower cover-3; groove-31; positive electrode material layer-4; copper-aluminum composite current collector-5; negative electrode material layer-6; solid electrolyte layer-7; soft insulating glue-8. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the utility model, but not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary persons in the field without creative work should fall within the scope of protection of the utility model.

[0025] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0026] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0027] The utility model is described in detail with reference to the schematic diagram. When describing the embodiments of the utility model, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general proportion, and the schematic diagrams are only examples, which should not limit the scope of protection of the utility model. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0028] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, left, right, inside and outside" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0029] In the present utility model, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or an integrated connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two original components. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to specific circumstances.

[0030] Embodiment 1

[0031] Reference below Figure 1 and Figure 2 , describes a solid-state battery according to an embodiment of the utility model, including a battery cell 2, an upper cover 1 and a lower cover 3, the battery cell 2 is arranged between the upper cover 1 and the lower cover 3, the upper cover 1 and the lower cover 3 are both U-shaped structures, the upper cover 1 is arranged above the lower cover 3, forming a rectangular structure with a hollow interior, the battery cell 2 is placed in the rectangular structure, a protrusion 11 is arranged at the lower end of the upper cover 1, the protrusion 11 extends toward the center line direction of the solid-state battery, grooves 31 are provided on the outer walls on both sides of the lower cover 3, the protrusion 11 extends into the groove 31, the upper cover 1 and the lower cover 3 are fixed in the vertical direction, thereby realizing the fixation of the internal battery cell 2, further, the width of the groove 31 in the vertical direction is greater than the width of the protrusion 11 in the vertical direction, so that the upper cover 1 can move up and down on the lower cover 3 in the vertical direction.

[0032] It should be noted that solid-state batteries have a large impedance and a high cost. The large impedance is mainly reflected in the difficulty in sufficient contact between the internal structures of the battery cell 2, which in turn forms an interface resistance. In order to reduce the resistance, it is necessary to provide a clamping force of hundreds of megahertz when actually assembling the battery cell 2. During the clamping process, the thickness of the battery cell 2 will decrease accordingly. In the solid-state battery in this embodiment, the protrusion 11 of the upper cover 1 cooperates with the groove 31 of the lower cover 3 to fix the battery cell 2. After fixation, a clamping force is applied to the upper cover 1 to press the battery cell 2 downward to reduce the thickness of the battery cell 2. When the thickness of the battery cell 2 is reduced, since the width of the groove 31 in the vertical direction is greater than the width of the protrusion 11 in the vertical direction, the protrusion 11 can move in the groove 31 to absorb the reduction in thickness of the battery cell 2 caused by the clamping force during assembly, thereby achieving the fixing effect of the upper cover 1 and the lower cover 3 on the battery cell 2.

[0033] It should be noted that, refer to Figure 2 The battery cell 2 includes a plurality of electrode units, and the electrode units are internally connected in series, that is, the plurality of electrode units are stacked layer by layer, and ions are transferred between the upper and lower electrode units, so that the battery cell forms a stacked core in the form of an internal series connection. The battery cell has the characteristics of very high voltage and low capacity. The plurality of electrode units at least include a copper-aluminum composite current collector 5, a positive electrode material layer 4, a negative electrode material layer 6 and a solid electrolyte layer 7. The positive electrode material layer 4 and the negative electrode material layer 6 are arranged on the upper and lower surfaces of the copper-aluminum composite current collector 5. One or more solid electrolyte layers 7 are arranged on the surface of the positive electrode material layer 4 or the negative electrode material layer 6. Furthermore, one side of the copper-aluminum composite current collector 5 is aluminum, and the other side is copper. The positive electrode material layer 4 is in contact with the aluminum surface, and the negative electrode material layer 6 is in contact with the copper surface. The copper-aluminum composite current collector 5 can be hot-pressed or extruded to embed and combine the two materials of copper and aluminum into a special structure with aluminum on one side and copper on the other side. The positive and negative electrode materials are integrated on a foil through a composite copper-aluminum foil. The positive electrode material layer 4 is coated on the aluminum surface, and the negative electrode material layer 6 is coated on the copper surface. One or more solid dielectric layers 7 are sprayed on the surface of the positive or negative electrode material layer to form a series structure. Ions are transferred through a solid electrolyte, and then multiple electrode units are stacked to form an internal series connection, so that the battery cell 2 forms a high-voltage series electrode cell.

[0034] Furthermore, an insulating layer is provided around the positive electrode material layer 4 or blank space is left around the positive electrode material layer 4 to ensure that the positive electrode material layer 4 maintains a certain distance from the negative electrode material layer 6 to reduce the risk of short circuit. In this embodiment, the electrode units are directly stacked and connected in series without the need for internal pole ears, and there is no problem of pole ear wrinkling, which avoids production problems caused by pole ear wrinkling and improves manufacturing efficiency. The battery cell 2 itself can be regarded as a "grouping" process, which can improve space utilization, achieve lower internal resistance, higher energy density and current output, and no complicated connection is required in the subsequent packaging process.

[0035] In one embodiment, referring to Figure 3 The end of the protrusion 11 on the upper cover 1 extends upward to form a hook structure, and the upper end of the groove 31 extends upward to enter the interior of the lower cover 3. The upper end structure of the groove 31 cooperates with the hook structure. When the upper cover 1 moves upward, the hook structure of the protrusion 11 is tightly buckled in the groove 31 of the lower cover 3, further ensuring the fixing effect of the battery cell 2, and also preventing the upper cover 1 and the lower cover 3 from separating due to the battery cell 2 expanding due to charging during operation.

[0036] In one embodiment, referring to Figure 3 An inclined surface is arranged at the lower end of the groove 31, and the inclined surface extends from the bottom of the groove 31 to the outer wall of the lower cover 3. The height of the inclined surface on one side of the bottom of the groove 31 is higher than the height of the inclined surface on one side of the outer wall of the lower cover 3. A downwardly extending inclined surface is formed at the lower end of the groove 31, which is convenient for providing a travel track for the protrusion 11 to avoid damaging the protrusion 11.

[0037] It should be noted that, as a preferred embodiment, one side of the barb structure of the protrusion 11 is an inclined surface. When one side of the barb structure is an inclined surface, the inclination angle of the inclined surface at the lower end of the groove 31 is the same as the inclination angle of the inclined surface of the barb structure, so that when the clamping force is pressed downward, when the protrusion 11 exceeds the groove 31, the protrusion 11 can move downward along the inclined surface of the groove 31 to avoid damage to the protrusion 11.

[0038] In one embodiment, referring to Figure 3 The upper cover 1 and the lower cover 3 include a metal plate and an extension plate. The metal plate is a U-shaped structure. The two sides of the metal plate are wrapped with the extension plate, and the length of the extension plate is greater than the length of the two sides of the U-shaped structure of the metal plate. The upper and lower sides of the battery cell 2 are in direct contact with the metal plate, and the side wall of the battery cell 2 is in contact with the extension plate. The metal plate of the upper cover 1 is an aluminum plate 12, and the metal plate of the lower cover 3 is a copper plate. The extension plate wrapped with the aluminum plate 12 is a first extension plate 13, and the protrusion 11 is arranged at the end of the first extension plate 13. The extension plate wrapped with the copper plate 32 is a second extension plate 33, and the groove 31 is arranged on the outer wall of the second extension plate 33.

[0039] Specifically, the upper cover 1 includes an aluminum plate 12 and a first extension plate 13. The aluminum plate 12 is a U-shaped structure. The aluminum plate 12 is in contact with the battery cell 2. The aluminum plate 12 is used as the positive electrode of the entire battery. The first extension plate 13 is wrapped on both sides of the aluminum plate 12. The first extension plate 13 extends downward. The protrusion 11 is arranged at the end of the first extension plate 13 and is connected to the lower cover 3. The first extension plate 13 is an insulating material. In actual application, the first extension plate 13 can use plastic as an insulating material to isolate the electrode unit from contacting the aluminum plate 12. The lower cover 3 includes a copper plate 32 and a second extension plate 33. The copper plate 32 is a U-shaped structure. The copper plate 32 In contact with the battery cell 2, the copper plate 32 is the negative output terminal and is used as the negative electrode of the entire battery. The second extension plate 33 is wrapped on both sides of the copper plate 32. The second extension plate 33 extends upward. The groove 31 is arranged on the outer wall of the second extension plate 33 so that the protrusion 11 extends into the groove 31 to fix the internal battery cell 2. The second extension plate 33 is an insulating material. Similar to the above embodiment, the second extension plate 33 can use plastic as an insulating material to isolate the electrode unit from contact with the copper plate 32. The composite method between the plastic and the aluminum plate 12 or the copper plate 32 is: drilling holes on the side of the aluminum plate 12 or the copper plate 32 to facilitate injection molding of plastic parts.

[0040] It should be noted that the extension plate is an elastic insulating material. When the first extension plate 13 or the second extension plate 33 is elastic, when the upper cover 1 is subjected to a clamping force, there is a certain buffer in the contact between the protrusion 11 and the groove 31, which can play a certain protective effect. In addition, the upper cover 1 and the lower cover 3 also contain metal materials, which can withstand greater pressure and ensure stable internal operation. In addition, it also prevents the aluminum plate 12 and the copper plate 32 from directly contacting the internal battery cell 2 to cause a short circuit.

[0041] In one embodiment, referring to Figure 1 The solid-state battery of the present application also includes a soft insulating glue 8, which is distributed at least on two side surfaces of the battery cell 2 not covered by the upper cover 1 and the lower cover 3. The soft insulating glue 8 is used on both sides of the battery cell 2 not covered by the upper cover 1 and the lower cover 3 to connect and fix multiple motor units into a whole. Structural glue can be used in actual application. When the thickness of the battery cell 2 is reduced, in order to avoid gaps between the battery cell 2 and the upper and lower covers, insulating sealant can be used to fill the gaps.

[0042] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A solid-state battery, comprising a battery cell (2), an upper cover (1) and a lower cover (3), wherein the battery cell (2) is arranged between the upper cover (1) and the lower cover (3), characterized in that: The upper cover (1) and the lower cover (3) are both U-shaped structures, the upper cover (1) is arranged above the lower cover (3), a protrusion (11) is arranged at the lower end of the upper cover (1), and the protrusion (11) extends in the direction of the center line of the solid-state battery; Grooves (31) are provided on the outer walls on both sides of the lower cover (3), the protrusion (11) extends into the groove (31), and the width of the groove (31) in the vertical direction is greater than the width of the protrusion (11) in the vertical direction.

2. The solid-state battery according to claim 1, characterized in that: The end of the protrusion (11) extends upward to form a barb structure.

3. The solid-state battery according to claim 2, characterized in that: The upper end structure of the groove (31) cooperates with the barb structure.

4. The solid-state battery according to claim 1, characterized in that: An inclined surface is provided at the lower end of the groove (31), the inclined surface extending from the bottom of the groove (31) to the outer wall of the lower cover (3), and the height of the inclined surface on one side of the bottom of the groove (31) is higher than the height of the inclined surface on one side of the outer wall of the lower cover (3).

5. The solid-state battery according to claim 1, characterized in that: The upper cover (1) and the lower cover (3) comprise a metal plate and an extension plate, wherein the metal plate is a U-shaped structure, the two sides of the metal plate wrap around the extension plate, the length of the extension plate is greater than the length of the two sides of the U-shaped structure of the metal plate, the upper and lower sides of the battery cell (2) are in contact with the metal plate, and the side wall of the battery cell (2) is in contact with the extension plate.

6. The solid-state battery according to claim 5, characterized in that: The metal plate of the upper cover (1) is an aluminum plate (12), the metal plate of the lower cover (3) is a copper plate, the extension plate wrapping the aluminum plate (12) is a first extension plate (13), and the extension plate wrapping the copper plate (32) is a second extension plate (33).

7. The solid-state battery according to claim 6, characterized in that: The protrusion (11) is arranged at the end of the first extension plate (13), and the groove (31) is arranged on the outer wall of the second extension plate (33).

8. The solid-state battery according to any one of claims 5 to 7, characterized in that: The extension plate is made of elastic insulating material.

9. The solid-state battery according to claim 5, characterized in that: Holes are drilled at the bending positions of the U-shaped structure of the metal plate, and the extension plates are wrapped around two sides of the U-shaped structure of the metal plate by injection molding.

10. The solid-state battery according to claim 1, characterized in that: It also includes soft insulating glue (8), and the soft insulating glue (8) is distributed on at least two side surfaces of the battery core (2) not covered by the upper cover (1) and the lower cover (3).

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