Solid-state battery cell, solid-state battery monomer, solid-state battery and power utilization device

Abstract

The utility model relates to a solid-state battery cell, a solid-state battery monomer, a solid-state battery and a power utilization device. The solid-state battery cell comprises a positive electrode part, a solid electrolyte part and a negative electrode part which are stacked, wherein the positive electrode part and the negative electrode part are isolated by the solid electrolyte part; the positive electrode part comprises a positive electrode body and a positive electrode lug part connected to the positive electrode body, and the negative electrode part comprises a negative electrode body and a negative electrode lug part connected to the negative electrode body; at the edge of at least one side extending along the width direction of the solid-state battery cell, the solid-state battery cell is provided with a first composite groove and a second composite groove, the first composite groove is used for accommodating at least one part of the positive electrode lug part, and the second composite groove is used for accommodating at least one part of the negative electrode lug part. At the moment, in the width direction of the solid-state battery cell, the solid-state battery cell is provided with an active expansion region which is consistent with the first composite groove and the second composite groove in height in a space region except the positive and negative electrode lug parts. The solid-state battery cell can be used for improving the volume energy density of the battery.

Description

Technical Field

[0001] The present application relates to the technical field of solid-state batteries, and further relates to solid-state battery cells, solid-state battery monomers, solid-state batteries, and electrical devices. Background Art

[0002] The statements herein only provide background information related to the present application and do not necessarily constitute prior art.

[0003] Solid-state batteries use non-flammable solid electrolytes to replace the organic electrolytes in traditional liquid secondary batteries, greatly improving the safety of the batteries, and are considered to be the new generation of batteries closest to industrialization. Further improving the energy density is of great significance for promoting the industrialization of solid-state batteries. Summary of the Utility Model

[0004] According to various embodiments and examples of the present application, the present application provides a solid-state battery cell, a solid-state battery monomer, a solid-state battery, and an electrical device. The solid-state battery cell can be used to improve the energy density of the battery.

[0005] In a first aspect, the present application provides a solid-state battery cell provided with an active expansion region.

[0006] In some embodiments, the present application provides a solid-state battery cell including a stacked positive electrode portion, a solid electrolyte portion, and a negative electrode portion, the positive electrode portion and the negative electrode portion being separated by the solid electrolyte portion; the positive electrode portion includes a positive electrode body and a positive electrode ear connected to the positive electrode body, and the negative electrode portion includes a negative electrode body and a negative electrode ear connected to the negative electrode body;

[0007] Denote the height direction of the solid-state battery cell as the Y direction, the width direction as the X direction, and the thickness direction as the Z direction; the X direction, the Y direction, and the Z direction are perpendicular to each other;

[0008] At least one side edge extending along the X direction, the solid-state battery cell is provided with two composite grooves, respectively denoted as a first composite groove and a second composite groove; the first composite groove is used to accommodate at least a part of the positive electrode ear, and the second composite groove is used to accommodate at least a part of the negative electrode ear.

[0009] The solid-state battery cell is provided with a first composite groove at the positive electrode tab portion for the positive electrode tab to bend inward, and a second composite groove at the negative electrode tab portion for the negative electrode tab to bend inward. At this time, an active expansion region is provided in a region that is at the same height as the first composite groove and the second composite groove and is located outside the first composite groove and the second composite groove in the width direction of the solid-state battery cell; that is, in the width direction of the solid-state battery cell, an active expansion region with the same height as the first composite groove and the second composite groove is provided in the space region outside the positive electrode tab and the negative electrode tab of the solid-state battery cell, enabling the solid-state battery cell to better utilize the space at the tab, thereby greatly increasing the space volume occupied by the electrode portion in the solid-state battery cell and significantly improving the volume energy density of the solid-state battery cell and the solid-state battery. The two composite grooves can also provide a protective effect on the tab portion and reduce the risk of tab breakage.

[0010] In some embodiments, in the solid-state battery cell, an active region that is at the same height as the first composite groove and the second composite groove in the Y direction and is located outside the first composite groove and the second composite groove in the X direction is denoted as the active expansion region;

[0011] The height of the positive electrode body at the active expansion region is higher than the height of the positive electrode body at the first composite groove, and the height of the negative electrode body at the active expansion region is higher than the height of the negative electrode body at the second composite groove;

[0012] Denote the height of the positive electrode body in the Y direction as H P , denote the height of the negative electrode body in the Y direction as H N , denote the height of the solid-state battery cell in the Y direction as H0; Denote the height region of the solid-state battery cell in the Y direction where the two composite grooves are provided as the active expansion region, and denote the maximum height of the active expansion region in the Y direction as H Δ , satisfying H Δ >0; H P >(H0 - H Δ ) and H N >(H0 - H Δ ).

[0013] In the above-mentioned solid-state battery cell structure, the height of the positive electrode body at the active expansion region is higher than the height of the positive electrode body at the first composite groove, and the height of the negative electrode body at the active expansion region is higher than the height of the negative electrode body at the second composite groove, enabling the solid-state battery cell to better utilize the space at the tab, thereby greatly increasing the space volume occupied by the electrode portion in the solid-state battery cell and significantly improving the volume energy density of the solid-state battery cell and the solid-state battery.

[0014] In some embodiments, H NIt is equal to H0. At this time, the space at the tab can be utilized to the greatest extent to set the electrode active material layer, thereby maximizing the volumetric energy density of the solid-state battery cell and the solid-state battery.

[0015] In some embodiments, the utilization rate ψ of the active expansion region in the Y direction Y = H Δ / H0×100%;

[0016] The solid-state battery cell satisfies one or more of the following characteristics:

[0017] H Δ ≥0.05 mm;

[0018] ψ Y ≥0.05%.

[0019] In some embodiments, the solid-state battery cell satisfies one or more of the following characteristics:

[0020] 0.05 mm ≤ H Δ ≤1 mm;

[0021] 0.1% ≤ ψ Y ≤2%.

[0022] By regulating one or both of the height parameter h of the active expansion region Δ and the utilization rate parameter ψ Y within the aforementioned range, it is beneficial to better utilize the space in the height direction at the tab position.

[0023] In some embodiments, the width of the solid-state battery cell in the X direction is denoted as W0, and the width of the active expansion region in the X direction is denoted as W Δ , and the utilization rate ψ of the active expansion region in the X direction X = W Δ / W0×100%;

[0024] The solid-state battery cell satisfies one or more of the following characteristics:

[0025] W Δ ≥50 mm;

[0026] ψ X ≥60%.

[0027] In some embodiments, the solid-state battery cell satisfies one or more of the following characteristics:

[0028] 50 mm ≤ W Δ ≤1000 mm;

[0029] 60% ≤ ψ X≤95%.

[0030] By regulating one or both of the width parameter w of the active expansion region Δ and the utilization rate parameter ψ X within the aforementioned range, it is beneficial to better utilize the space in the width direction at the tab position.

[0031] In some embodiments, the projected area of the solid-state battery cell along the Z direction is denoted as A0, and the projected area of the active expansion region along the Z direction is denoted as A Δ , and the two-dimensional utilization rate ψ of the active expansion region A = A Δ / A0 × 100%;

[0032] The solid-state battery cell satisfies: ψ A ≥0.04%.

[0033] In some embodiments, the solid-state battery cell satisfies: 0.04% ≤ ψ A ≤1.5%.

[0034] By regulating the two-dimensional utilization rate ψ of the active expansion region A within the aforementioned range, it is beneficial to better comprehensively utilize the idle space at the tab.

[0035] In some embodiments, the stretching height of the positive tab in the Y direction when in the stretched state is greater than the height of the first composite groove in the Y direction;

[0036] The stretching height of the negative tab in the Y direction when in the stretched state is greater than the height of the second composite groove in the Y direction.

[0037] By reserving a certain stretching height for the positive tab or the negative tab, it is convenient to use it as a flexible tab to connect to a rigid tab in subsequent processes.

[0038] In some embodiments, the positive tab includes a positive tab bending portion located within the first composite groove; the negative tab includes a negative tab bending portion located within the second composite groove.

[0039] At least a part of each of the positive tab and / or the negative tab in the solid-state battery cell can be bent inward into the corresponding composite groove. When sufficient height of the positive and negative tabs is reserved, it is beneficial to further increase the volume occupancy rate of the electrode portion in the solid-state battery cell, and can greatly improve the volume energy density of the solid-state battery cell and the solid-state battery.

[0040] In some embodiments, the width of the positive tab in the X direction is less than the width of the first composite groove in the X direction;

[0041] The width of the negative electrode tab in the X direction is less than the width of the second composite groove in the X direction.

[0042] In some embodiments, in the X direction, there are gaps between the positive electrode tab and the two side edges of the first composite groove, and there are gaps between the negative electrode tab and the two side edges of the second composite groove.

[0043] By leaving a certain gap for the two side edges of the corresponding electrode tabs at the composite groove, a suitable moving space can be reserved for the positive and negative electrode tabs, and it also allows the positive and negative electrode tabs to be bent into the composite groove more conveniently.

[0044] In some embodiments, the solid-state battery cell has a laminated structure.

[0045] In some embodiments, the positive electrode body includes at least one layer of positive electrode layer, and each positive electrode layer is provided with grooves corresponding to the first composite groove and the second composite groove respectively. A positive electrode tab is provided at the groove corresponding to the first composite groove in at least one layer of the positive electrode layer;

[0046] The negative electrode body includes at least one layer of negative electrode layer, and each negative electrode layer is provided with grooves corresponding to the second composite groove and the first composite groove respectively. A negative electrode tab is provided at the groove corresponding to the second composite groove in at least one layer of the negative electrode layer;

[0047] The solid electrolyte part includes at least one layer of solid electrolyte layer, and any adjacent positive electrode layer and negative electrode layer are isolated by the solid electrolyte layer; each solid electrolyte layer is provided with empty grooves corresponding to the first composite groove and the second composite groove respectively.

[0048] In some of these embodiments, the positive electrode body includes at least one layer of positive electrode layer, and each positive electrode layer independently includes a positive electrode current collector layer and a positive electrode active material layer located on at least one side of the positive electrode current collector layer. Each positive electrode layer is provided with a positive electrode tab groove, and all the positive electrode tab grooves in the positive electrode body together form a part of the first composite groove. The positive electrode current collector layer in at least one layer of the positive electrode layer is connected with a positive electrode tab at the corresponding positive electrode tab groove, and all the positive electrode tabs connected by the positive electrode body together form at least a part of the positive electrode tab;

[0049] The negative electrode body includes at least one layer of negative electrode layers. Each negative electrode layer independently includes a negative electrode current collector layer and a negative electrode active material layer located on at least one side of the negative electrode current collector layer. All the negative electrode layers are provided with negative electrode tab grooves. All the negative electrode tab grooves in the negative electrode body together form a part of the first composite groove. The negative electrode current collector layer in at least one layer of the negative electrode layers is connected with a negative electrode tab at the corresponding negative electrode tab groove. All the negative electrode tabs connected to the negative electrode body together form at least a part of the negative electrode tab portion.

[0050] When the solid-state battery cell adopts the aforementioned stacked structure, at the first composite groove, the concave space for the positive electrode tab to bend inward can be formed by combining the positive electrode tab groove on the positive electrode layer, the empty groove on the negative electrode layer, and the empty groove on the solid electrolyte layer; at the second composite groove, the concave space for the negative electrode tab to bend inward can be formed by combining the negative electrode tab groove on the negative electrode layer, the empty groove on the positive electrode layer, and the empty groove on the solid electrolyte layer.

[0051] In some embodiments, the number of layers of the positive electrode layers in the positive electrode body is multiple; the number of layers of the negative electrode layers in the negative electrode body matches the number of layers of the positive electrode layers in the positive electrode body.

[0052] When the number of layers of the positive electrode layers in the positive electrode body is multiple and the number of layers of the negative electrode layers in the negative electrode body is multiple and matching, the stacked structure corresponds to a multi-layer stacked structure. At this time, using the aforementioned active expansion region structure design is beneficial to gain more volumetric energy density at the tab space.

[0053] In some embodiments, multiple positive electrode layers in the positive electrode body are connected with the positive electrode tab; multiple negative electrode layers in the negative electrode body are connected with the negative electrode tab.

[0054] When multiple positive electrode layers in the positive electrode body are all connected with the positive electrode tab and multiple negative electrode layers in the negative electrode body are all connected with the negative electrode tab, it is more beneficial to save the waste of the internal space of the shell caused by the stacking of multiple tabs.

[0055] In the second aspect of the present application, a solid-state battery cell is provided, which includes the solid-state battery cell described in the first aspect of the present application.

[0056] In the third aspect of the present application, a solid-state battery is provided, which includes the solid-state battery cell described in the first aspect of the present application.

[0057] In some embodiments, the solid-state battery is a all-solid-state battery.

[0058] In the fourth aspect of the present application, an electrical device is provided, which includes at least one of the solid-state battery cell described in the first aspect of the present application, the solid-state battery cell described in the second aspect of the present application, and the solid-state battery described in the third aspect of the present application.

[0059] The solid - state battery cell and the solid - state battery including the aforementioned solid - state battery cells increase the volume of the electrode body at the tab height, improve the space occupancy rate of the electrode active material layer, and can greatly improve the volumetric energy density.

[0060] Details of one or more embodiments or examples of the present application are set forth in the following drawings and description. Other features, objects, and advantages of the present application will become apparent from the specification, the drawings, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] To better describe and illustrate the embodiments, examples, or instances provided by the present application, one or more drawings may be referred to. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, the currently described embodiments, examples, or instances, or the best mode currently understood for these applications. Moreover, in all the drawings, the same reference numerals are used to represent the same components. It should also be noted that the drawings are all drawn in simplified forms and are only used to facilitate and clearly assist in the description of the present application. The various dimensions of each component shown in the drawings are arbitrarily shown, which may be accurate or may not be drawn to actual scale. For example, to make the illustration clearer, the dimensions of some components in the drawings are appropriately exaggerated. Unless otherwise specified, the components in the drawings are not drawn to scale. The present application does not limit each dimension of each component.

[0062] In the drawings:

[0063] Figure 1 is a schematic structural view of a solid - state battery cell in an embodiment of the present application; where (a) is a front view, and (A - A), (B - B), and (C - C) are cross - sectional views at the A - A, B - B, and C - C positions respectively; the dashed lines are reference lines.

[0064] Figure 2 is a schematic view of the preparation process of the positive electrode plate and the negative electrode plate in an embodiment of the present application; where (a) corresponds to three structures involved in the preparation process of the positive electrode plate from left to right, which are the positive electrode current collector film material, the positive electrode multi - layer body formed by laminating a positive electrode active region with a positive electrode concave blank region on the surface of the positive electrode current collector film material, and the positive electrode plate including the positive electrode tab formed by die - cutting; (b) corresponds to three structures involved in the preparation process of the negative electrode plate from left to right, which are the negative electrode current collector film material, the negative electrode multi - layer body formed by laminating a negative electrode active region with a negative electrode concave blank region on the surface of the negative electrode current collector film material, and the negative electrode plate including the negative electrode tab formed by die - cutting.

[0065] Figure 3 is a schematic view of a solid - state battery cell according to an embodiment of the present application.

[0066] Figure 4 For Figure 3 the exploded view of a solid - state battery cell of an embodiment of the present application as shown.

[0067] Figure 5 The schematic diagram of a battery module of an embodiment of the present application.

[0068] Figure 6 The schematic diagram of a battery pack of an embodiment of the present application.

[0069] Figure 7 For Figure 6 the exploded view of a battery pack of an embodiment of the present application as shown.

[0070] Figure 8 The schematic diagram of an electrical device using a solid - state battery of an embodiment of the present application as a power source.

[0071] Explanation of reference numerals:

[0072] 10, positive electrode layer; 20, solid electrolyte layer; 30, negative electrode layer; 1300, positive electrode ear; 1302, first composite groove; 3300, negative electrode ear; 3302, second composite groove; X is the X - direction; Y is the Y - direction; Z is the Z - direction; 100, positive electrode plate; 111, positive electrode current collector film material; 120, positive electrode active region; 121, positive electrode inner concave blank region; 130, positive electrode ear; 122, positive electrode ear groove; 124, first empty groove; 300, negative electrode plate; 311, negative electrode current collector film material; 320, negative electrode active region; 321, negative electrode inner concave blank region; 330, negative electrode ear; 322, negative electrode ear groove; 324, second empty groove; 1, battery pack; 2, upper box body; 3, lower box body; 4, battery module; 5, solid - state battery cell; 51, housing; 52, solid - state battery core; 53, cover plate; 6, electrical device. Detailed embodiments

[0073] Hereinafter, some embodiments of the solid - state battery core, solid - state battery cell, solid - state battery, and electrical device of the present application are described in detail with appropriate reference to the drawings. However, there may be cases where non - essential detailed descriptions are omitted. For example, there are cases where detailed descriptions of well - known matters and repeated descriptions of actually identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter recited in the claims.

[0074] The "range" disclosed in this application can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The ranges defined in this way can include or exclude the end values. Any end value can be independently included or excluded, and any combination can be made, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 - 120 and 80 - 110 are listed for a specific parameter, ranges of 60 - 110 and 80 - 120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are also listed, the following ranges are all contemplated: 1 - 3, 1 - 4, 1 - 5, 2 - 3, 2 - 4, and 2 - 5. In this application, unless otherwise specified, the numerical range "a - b" represents an abbreviated representation of any real number combination between a and b, where both a and b are real numbers. For example, the numerical range "0 - 5" means that all real numbers between "0 - 5" are fully listed herein, and "0 - 5" is only an abbreviated representation of these numerical combinations. Additionally, when stating that a certain parameter is an integer ≥2, it is equivalent to listing the parameter as integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For example, when stating that a certain parameter is an integer selected from "2 - 10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0075] In this application, when referring to "multiple", "diverse", "a number of", "several", etc., unless otherwise specified, it means greater than 2 or equal to 2 in quantity. For example, "one or more" means one or ≥ (greater than or equal to) two. It can be understood that when referring to "any number of" items, it refers to any suitable combination of multiple items, that is, the "any number of" items are combined in a non - conflicting and implementable manner of this application.

[0076] If there is no special instruction, all embodiments and optional embodiments of this application can be combined with each other to form a new technical solution.

[0077] Referring to "embodiment" in this text means that the specific features, structures, or characteristics described in combination with the embodiment can be included in at least one embodiment or implementation manner of this application. The appearance of this phrase at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments. The understanding of "implementation manner" mentioned in this text is similar.

[0078] In this application, in an open technical feature or technical solution described by words such as "containing", "including", and "comprising", without other explanations, additional members outside the listed members are not excluded, and it can be regarded as providing both a closed feature or solution composed of the listed members and an open feature or solution that also includes additional members outside the listed members. For example, a includes a1, a2, and a3. Without other explanations, it may also include other members or may not include additional members, and it can be regarded as providing both a feature or solution of "a consists of a1, a2, and a3" or "a is selected from a1, a2, and a3", and a feature or solution of "a not only includes a1, a2, and a3, but also includes other members".

[0079] In this application, without other explanations, M (such as m1) means that m1 is a non-limiting example in M, and it can be understood that M is not limited to m1.

[0080] In this application, "optionally", "optional", and "option" mean that it can be either present or absent, that is, it refers to any one of two alternative options of "present" or "absent". If "optional" appears multiple times in a technical solution, without special explanations and without contradictions or mutual restrictions, each "optional" is independent. Without other explanations, descriptions such as "optionally include" and "optionally contain" in this application, taking "optionally include" as an example, mean "may include or may not include".

[0081] In this application, without other explanations, the feature or solution corresponding to "and / or" includes any one of two or more related listed items, and also includes any and all combinations of the related listed items. Among them, any and all combinations include combinations of any two related listed items, any more related listed items, or all related listed items. For example, "M and / or N" means the set composed of M, N, and "the combination of M and N". Among them, "containing M and / or N" can mean "containing M, containing N, and containing the combination of M and N", or can also mean "containing M, containing N, or containing the combination of M and N", which can be appropriately understood according to the context of the sentence.

[0082] "Their combination", "any combination thereof", "any combination mode thereof", etc. used in this article include all suitable combination modes of any two or more of the listed items.

[0083] In this article, "suitable combination mode", "suitable mode", "any suitable mode", etc., the "suitable" is subject to being able to implement the technical solution of this application.

[0084] In this text, "preferred", "better", "more preferred", "should preferably be", "relatively good", "more preferable" are only used to describe embodiments or examples with better effects. It should be understood that they do not constitute a limitation on the protection scope of this application. If "preferred" appears multiple times in a technical solution, without special instructions and without contradictions or mutual restrictions, each "preferred" is independent of each other.

[0085] In this application, "further", "even further", "especially", "for example", "such as", "example", "for illustration" are used for descriptive purposes, indicating differences in content, but should not be construed as a limitation on the protection scope of this application.

[0086] In this application, in "the first aspect", "the second aspect", "the third aspect", "the fourth aspect", etc., the terms "first", "second", "third", "fourth", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0087] In the description of this application, it should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "thickness", "height", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on this application.

[0088] In this application, unless otherwise clearly specified and limited, terms such as "connected" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0089] In this application, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. In this application, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature can represent the mutual positional relationship in terms of horizontal height, or can only represent an attachment relationship without limiting the mutual positional relationship in terms of horizontal height.

[0090] In this application, the term "room temperature" generally refers to 4°C to 35°C, and can refer to 20°C ± 5°C. In some embodiments or examples of this application, room temperature refers to 20°C to 30°C.

[0091] In this application, for units related to data ranges, if the unit is only attached after the right endpoint, it means that the units of the left endpoint and the right endpoint are the same. For example, both 3 to 5 mm or 3 - 5 mm indicate that the units of the left endpoint "3" and the right endpoint "5" are both mm (millimeters), and have the same meaning as 3 mm to 5 mm. In addition, similar descriptions of other parameters such as temperature and size are understood in the same way.

[0092] In this application, "greater than or equal to", "more than or equal to", and "≥" have the same meaning and can be used interchangeably; "less than or equal to", "less than or equal to", and "≤" have the same meaning and can be used interchangeably; "greater than" can be equivalently expressed as ">", and "less than" can be equivalently expressed as "<". In this application, unless otherwise specified, "greater than or equal to" and "≥" can be regarded as also providing two options of "greater than" and "equal to". In this application, unless otherwise specified, "less than or equal to" and "≤" can be regarded as also providing two options of "less than" and "equal to".

[0093] In this application, for exemplary descriptions such as "in some embodiments (or examples)" and "in one embodiment (or example)", it can cover but is not limited to the following meanings: These solutions can be combined with other solutions in a suitable manner to form new technical solutions.

[0094] The improvement effects described in this application are not intended to be limited to any theory unless otherwise specified.

[0095] In traditional solid-state batteries, the die-cut soft tab is located outside the electrode active material layer. After assembling into a battery cell, the soft tab hangs outside the active area of the electrode sheet. In order to be able to transfer to a hard tab after fitting multiple soft tabs together after putting them into the shell, a certain space inside the shell needs to be reserved for the soft tab. After encapsulating the electrode assembly into the shell, since the soft tab occupies a certain height space, there is always a certain gap between the top of the electrode sheet and the bottom of the shell. The area outside the tab corresponding to this gap is usually vacant, resulting in a fixed loss of the space inside the shell. In addition, the side of the soft tab is easily stressed and cracked, increasing the impedance of the battery cell and affecting the performance of the battery cell.

[0096] In the present application, the "soft tab" can be obtained by die-cutting the current collector in the electrode sheet, and at the same time, a current collector layer that matches the position of the electrode active material layer is obtained. That is to say, the soft tab and the current collector layer in the electrode sheet can be integrated. However, it is not limited thereto. Non-restrictively, the material of the soft tab can be the same as that of the corresponding current collector layer. In some non-restrictive embodiments, the soft tab and the current collector layer can be from the same film material. At least a part of the film material forms the current collector layer, and at least another part forms the soft tab. At this time, the soft tab and the current collector layer in the electrode sheet can be integrated.

[0097] In the present application, unless otherwise specified, the "hard tab" refers to the tab segment located outside the battery case, which is a metal conductor used to lead out the positive and negative electrodes from the battery cell. Non-restrictively, aluminum can be used as the metal part of the positive hard tab, and nickel can be used as the metal part of the negative hard tab.

[0098] Based on this, the present application provides a solid-state battery cell, a solid-state battery monomer, a solid-state battery, and an electrical device. The solid-state battery cell can be used to improve the energy density of the battery.

[0099] In some embodiments, the solid-state battery cell includes a stacked positive electrode portion, a solid electrolyte portion, and a negative electrode portion. The positive electrode portion and the negative electrode portion are separated by the solid electrolyte portion; the positive electrode portion includes a positive electrode body and a positive electrode tab connected to the positive electrode body, and the negative electrode portion includes a negative electrode body and a negative electrode tab connected to the negative electrode body; at least one side edge extending in the width direction of the solid-state battery cell is provided with a first composite groove and a second composite groove. The first composite groove is used to accommodate at least a part of the positive electrode tab, and the second composite groove is used to accommodate at least a part of the negative electrode tab.

[0100] At this time, in the width direction of the solid-state battery cell, an active expansion area is provided in the space area of the solid-state battery cell other than the positive and negative electrode tabs. The solid-state battery cell can be used to improve the volumetric energy density of the battery.

[0101] In the present application, unless otherwise specified, the "solid-state battery" provided in the present application refers to a battery in which the electrolyte in the battery includes a solid electrolyte; generally, the solid-state battery includes a positive electrode portion, a solid electrolyte portion, and a negative electrode portion. During the charge and discharge process of the battery, active ions are embedded and extracted back and forth between the positive electrode portion and the negative electrode portion. The solid electrolyte portion plays a role in conducting ions between the positive electrode portion and the negative electrode portion, and can also isolate the positive electrode portion and the negative electrode portion to prevent short-circuiting between the positive and negative electrodes. Therefore, a separator film in a traditional lithium-ion battery may not be provided in the solid-state battery. The solid-state battery uses a non-flammable solid electrolyte to replace the organic electrolyte in the traditional liquid lithium-ion battery, greatly improving the safety of the battery. In addition to improving safety, the solid-state battery can also better adapt to positive and negative electrode materials with high energy density and reduce the system weight, which is beneficial to improving the energy density while taking into account other factors.

[0102] In this application, unless otherwise specified, the "solid electrolyte part" refers to the structural part including the solid electrolyte. The solid electrolyte part includes at least one layer of solid electrolyte layer, and the number of solid electrolyte layers matches the number of electrode layers in the electrode part.

[0103] In this application, unless otherwise specified, the "solid electrolyte" refers to an electrolyte material or electrolyte substance that exists in a solid state during the storage and preparation of solid-state batteries and components constituting solid-state batteries, as well as during the operation of solid-state batteries. It can be understood that, including but not limited to, at room temperature, the solid electrolyte exists in a solid state.

[0104] In this application, unless otherwise specified, the "electrode part" includes a positive electrode part and a negative electrode part. The positive electrode part includes a positive electrode body and a positive electrode ear connected to the positive electrode body, and the negative electrode part includes a negative electrode body and a negative electrode ear connected to the negative electrode body.

[0105] In this application, unless otherwise specified, the "electrode part" includes an electrode body and an electrode ear connected to the electrode body. The "electrode body" can be a positive electrode body or a negative electrode body. The electrode body in the positive electrode part is the positive electrode body, and the electrode body in the negative electrode part is the negative electrode body.

[0106] In this application, unless otherwise specified, the "electrode body" includes at least one layer of electrode layer, and the electrode body can include one or more layers of electrode layers; the number of layers of the electrode body is consistent with the number of electrode layers in the electrode body. The "electrode body" can be a positive electrode body or a negative electrode body. The positive electrode body includes at least one layer of positive electrode layer, the positive electrode body can include one or more layers of positive electrode layers, and the number of layers of the positive electrode body is consistent with the number of positive electrode layers in the positive electrode body. The negative electrode body includes at least one layer of negative electrode layer, the negative electrode body can include one or more layers of negative electrode layers, and the number of layers of the negative electrode body is consistent with the number of positive electrode layers in the positive electrode body.

[0107] In this application, unless otherwise specified, a solid electrolyte layer is provided between any adjacent positive electrode layer and negative electrode layer. Therefore, the number of solid electrolyte layers in the solid electrolyte part matches the number of electrode layers in the electrode part.

[0108] Generally, a solid-state battery includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. During the charge and discharge process of the battery, active ions are embedded and extracted back and forth between the positive electrode layer and the negative electrode layer. The solid electrolyte layer plays a role in conducting ions between the positive electrode layer and the negative electrode layer, and can also isolate the positive electrode layer and the negative electrode layer to prevent short circuit between the positive and negative electrodes.

[0109] In some embodiments, each electrode layer independently includes a current collector layer and an electrode active material layer located on at least one side of the current collector layer. In some of these embodiments, each positive electrode layer independently includes a positive current collector layer and a positive electrode active material layer located on at least one side of the positive current collector layer, and each negative electrode layer independently includes a negative current collector layer and a negative electrode active material layer located on at least one side of the negative current collector layer.

[0110] In this application, unless otherwise specified, the "electrode active material layer" includes at least one of the positive electrode active material layer in the positive electrode layer and the negative electrode active material layer in the negative electrode layer. Depending on the specific situation, the electrode active material layer may refer to the positive electrode active material layer or the negative electrode active material layer. It can be understood that the positive electrode active material layer contains positive electrode active substances, and the negative electrode active material layer contains negative electrode active substances.

[0111] In this application, unless otherwise stated, the "tab" can be a positive tab or a negative tab. The tab in the positive electrode part is a positive tab, and the positive tab is connected to the positive electrode body. The tab in the negative electrode part is a negative tab, and the negative tab is connected to the negative electrode body.

[0112] In this application, unless otherwise stated, the "tab" independently includes at least one tab, and any one "tab" is independently connected to the current collector layer of the corresponding electrode layer. The positive tab includes at least one positive tab, and the positive tab is connected to the positive current collector layer of the corresponding positive electrode layer. The negative tab includes at least one negative tab, and the negative tab is connected to the negative current collector layer of the corresponding negative electrode layer. Each electrode layer may or may not be provided with a tab, but at least one positive electrode body is connected to a positive tab, and at least one negative electrode body is connected to a negative tab.

[0113] It can be understood that the connection between the tab and the corresponding electrode body is at least a physical connection, and electrical connection can also be achieved during the battery cycling process.

[0114] In this application, unless otherwise stated, the "electrode layer" includes electrode active substances. The electrode layer can be a positive electrode layer or a negative electrode layer. The "electrode active substances" in the electrode layer refer to substances that can reversibly insert and extract active ions. Unless otherwise stated, the "negative electrode active substances" refer to substances used in the negative electrode layer that can reversibly insert and extract active ions; the "positive electrode active substances" refer to substances used in the positive electrode layer that can reversibly extract and insert active ions. When the solid-state battery is charged, the active ions are extracted from the positive electrode and inserted into the negative electrode through the solid electrolyte layer; when the solid-state battery is discharged, the active ions are extracted from the negative electrode and inserted into the positive electrode. The active ions are not particularly limited, and non-restrictively, the active ions can be lithium ions, corresponding to a lithium-ion solid-state battery at this time.

[0115] In a first aspect, the present application provides a solid-state battery cell provided with an active extension region. The solid-state battery cell can be used to increase the energy density of the battery.

[0116] In the present application, unless otherwise specified, the height direction of the solid-state battery cell is denoted as the Y direction, the width direction is denoted as the X direction, and the thickness direction is denoted as the Z direction; the X direction, the Y direction, and the Z direction are perpendicular to each other.

[0117] In some embodiments, the present application provides a solid-state battery cell including a stacked positive electrode portion, a solid electrolyte portion, and a negative electrode portion, where the positive electrode portion and the negative electrode portion are isolated by the solid electrolyte portion; the positive electrode portion includes a positive electrode body and a positive electrode tab connected to the positive electrode body, and the negative electrode portion includes a negative electrode body and a negative electrode tab connected to the negative electrode body;

[0118] At least one side edge extending in the X direction, the solid-state battery cell is provided with two composite grooves, denoted as a first composite groove and a second composite groove respectively; the first composite groove is used to accommodate at least a part of the positive electrode tab, and the second composite groove is used to accommodate at least a part of the negative electrode tab.

[0119] In the present application, unless otherwise specified, in the solid-state battery cell, the active region that is at the same height as the first composite groove and the second composite groove in the Y direction and is located outside the first composite groove and the second composite groove in the X direction is denoted as the "active extension region".

[0120] In the present application, unless otherwise specified, the "active region" refers to the region in the solid-state battery cell where an electrode active material layer is provided as projected along the Z direction. Unless otherwise specified, both the positive electrode body and the negative electrode body correspond to the active region, the positive electrode body corresponds to the positive electrode active region, and the negative electrode body corresponds to the negative electrode body region. Unless otherwise specified, the active region of the solid-state battery cell corresponds to the region outside the positive electrode tab and the negative electrode tab as projected along the Z direction.

[0121] In the present application, unless otherwise specified, along the X direction, due to the presence of the first composite groove and the second composite groove, the active region of the solid-state battery cell has a concave shape at the corresponding edge.

[0122] In the present application, unless otherwise specified, "stacked arrangement" is used to describe the positional relationship of multiple layered structures, referring to the stacking of multiple layered structures along their respective thickness directions. Those skilled in the art can understand its meaning.

[0123] In the present application, unless otherwise specified, when referring to the "composite groove", it can be the first composite groove or the second composite groove, or it can refer to the combination of the first composite groove and the second composite groove. It can be appropriately understood in combination with the description method. For example, "two composite grooves" refers to the combination of the first composite groove and the second composite groove.

[0124] In this application, unless otherwise specified, the "first composite groove" refers to a groove in the solid-state battery cell that accommodates at least a part of the positive electrode tab. At least a part of the positive electrode tab is located within the concave area provided by the first composite groove. Unless otherwise specified, the positive electrode tab is connected to the positive electrode body at the bottom of the first composite groove. The "bottom of the first composite groove" refers to the side of the first composite groove that is farthest from the opening position in the Y direction, and it is also the top of the positive electrode body at this position that is closest to the first composite groove in the Y direction. Unless otherwise specified, the positive electrode tab is not connected to the two side edges of the first composite groove, so that the positive electrode tab can move in a direction perpendicular to the X direction.

[0125] In this application, unless otherwise specified, the "second composite groove" refers to a groove in the solid-state battery cell that accommodates at least a part of the negative electrode tab. At least a part of the negative electrode tab is located within the concave area provided by the second composite groove. Unless otherwise specified, the negative electrode tab is connected to the negative electrode body at the bottom of the second composite groove. The "bottom of the second composite groove" refers to the side of the second composite groove that is farthest from the opening position in the Y direction, and it is also the top of the negative electrode body at this position that is closest to the second composite groove in the Y direction. Unless otherwise specified, the negative electrode tab is not connected to the two side edges of the second composite groove, so that the negative electrode tab can move in a direction perpendicular to the X direction.

[0126] In this application, in the "first composite groove" and "second composite groove", the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or quantity, nor can they be construed as implicitly specifying the importance or quantity of the indicated technical features. Moreover, "first" and "second" only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0127] In this application, unless otherwise specified, the "active expansion area" is a part of the solid-state battery cell. The active expansion area is an active area provided with an electrode active material layer. The height of the active expansion area in the height direction (Y direction) of the solid-state battery cell is the same as that of the first composite groove and the second composite groove. The active expansion area is divided into discontinuous areas by the first composite groove and the second composite groove in the width direction (X direction) of the solid-state battery cell. The two side contours of the first composite groove and the second composite groove extending in the Y direction are provided by adjacent active expansion areas. The "active expansion area" can also be described as the height area of the solid-state battery cell with two composite grooves provided in the Y direction.

[0128] The solid-state battery cell is provided with a first composite groove at the positive electrode tab portion for the positive electrode tab to bend inward, and a second composite groove at the negative electrode tab portion for the negative electrode tab to bend inward. At this time, an active expansion region is provided in a region that is at the same height as the first composite groove and the second composite groove and is located outside the first composite groove and the second composite groove in the width direction of the solid-state battery cell; that is, in the width direction of the solid-state battery cell, an active expansion region with the same height as the first composite groove and the second composite groove is provided in the space region outside the positive electrode tab and the negative electrode tab of the solid-state battery cell, enabling the solid-state battery cell to better utilize the space at the tab, thereby greatly increasing the space volume occupied by the electrode portion in the solid-state battery cell and significantly improving the volumetric energy density of the solid-state battery cell and the solid-state battery. The two composite grooves can also provide a protective effect on the tab portion and reduce the risk of tab breakage.

[0129] In some embodiments, the height of the positive electrode body at the active expansion region is higher than the height of the positive electrode body at the first composite groove, and the height of the negative electrode body at the active expansion region is higher than the height of the negative electrode body at the second composite groove. At this time, the solid-state battery cell can better utilize the space at the tab, thereby greatly increasing the space volume occupied by the electrode portion in the solid-state battery cell and significantly improving the volumetric energy density of the solid-state battery cell and the solid-state battery.

[0130] In some embodiments, the present application provides a solid-state battery cell, which includes a stacked positive electrode portion, a solid electrolyte portion, and a negative electrode portion, and the positive electrode portion and the negative electrode portion are isolated by the solid electrolyte portion; the positive electrode portion includes a positive electrode body and a positive electrode tab connected to the positive electrode body, and the negative electrode portion includes a negative electrode body and a negative electrode tab connected to the negative electrode body;

[0131] At least one side edge extending in the X direction, the solid-state battery cell is provided with two composite grooves, denoted as the first composite groove and the second composite groove respectively; the first composite groove is used to accommodate at least a part of the positive electrode tab, and the second composite groove is used to accommodate at least a part of the negative electrode tab;

[0132] The height region of the solid-state battery cell provided with two composite grooves in the Y direction is denoted as the active expansion region, and the maximum height of the active expansion region in the Y direction is denoted as H Δ , satisfying H Δ > 0.

[0133] In the present application, unless otherwise specified, the height of the positive electrode body in the Y direction is denoted as H P , the height of the negative electrode body in the Y direction is denoted as H N , and the height of the solid-state battery cell in the Y direction is denoted as H0.

[0134] In some embodiments, H P > (H0 - H Δ ).

[0135] In some embodiments, H N >(H0 - H Δ ).

[0136] In some embodiments, H P >(H0 - H Δ ) and H N >(H0 - H Δ ).

[0137] In some embodiments, the present application provides a solid - state battery cell, which includes a stacked positive electrode portion, a solid electrolyte portion, and a negative electrode portion. The positive electrode portion and the negative electrode portion are separated by the solid electrolyte portion; the positive electrode portion includes a positive electrode body and a positive electrode tab connected to the positive electrode body, and the negative electrode portion includes a negative electrode body and a negative electrode tab connected to the negative electrode body;

[0138] Denote the height direction of the solid - state battery cell as the Y - direction, the width direction as the X - direction, and the thickness direction as the Z - direction; the X - direction, the Y - direction, and the Z - direction are perpendicular to each other;

[0139] At least one side edge extending along the X - direction, the solid - state battery cell is provided with two composite grooves, denoted as the first composite groove and the second composite groove respectively; the first composite groove is used to accommodate at least a part of the positive electrode tab, and the second composite groove is used to accommodate at least a part of the negative electrode tab;

[0140] Denote the height of the positive electrode body in the Y - direction as H P , the height of the negative electrode body in the Y - direction as H N , and the height of the solid - state battery cell in the Y - direction as H0; denote the height region where the solid - state battery cell has two composite grooves in the Y - direction as the active expansion region, and denote the maximum height of the active expansion region in the Y - direction as H Δ , satisfying H Δ >0;

[0141] In some of these embodiments, H P >(H0 - H Δ ) and H N >(H0 - H Δ ).

[0142] In the present application, unless otherwise specified, the "height of the positive electrode body in the Y - direction" refers to the maximum height of the positive electrode body in the Y - direction. In some embodiments, the height of the positive electrode body in the Y - direction is equal to the sum of the height of the positive electrode body at the first composite groove and the height of the first composite groove.

[0143] In this application, unless otherwise specified, the "height of the negative electrode body in the Y direction" refers to the maximum height of the negative electrode body in the Y direction. In some embodiments, the height of the negative electrode body in the Y direction is equal to the sum of the height of the negative electrode body at the second composite groove and the height of the second composite groove.

[0144] In this application, unless otherwise specified, the "height of the solid-state battery cell in the Y direction" refers to the maximum height of the electrode body in the Y direction. Unless otherwise specified, the "height of the solid-state battery cell in the Y direction" does not cover the height of the tab portion.

[0145] In this application, unless otherwise specified, the "maximum height of the active expansion region in the Y direction" is consistent with the maximum depth of the first composite groove and the second composite groove in the Y direction.

[0146] The solid-state battery cell has a certain extension length in the X direction and a certain extension height in the Y direction. The two top edges of the solid-state battery cells with a certain spacing in the Y direction can be denoted as "the two side edges of the solid-state battery cell extending in the X direction" or "the two side edges of the solid-state battery in the Y direction".

[0147] In this application, unless otherwise specified, "at least one side edge extending in the X direction, the solid-state battery cell is provided with two composite grooves" and "at least one side edge in the Y direction, the solid-state battery cell is provided with two composite grooves" have the same meaning and can be used interchangeably.

[0148] In this application, "at least one side edge extending in the X direction, the solid-state battery cell is provided with two composite grooves" means that the solid-state battery cell is provided with two composite grooves, and these two composite grooves are located on the same side edge of the solid-state battery cell extending in the X direction, or are respectively located on different side edges of the solid-state battery cell extending in the X direction. That is, these two composite grooves can be located on the same side of the solid-state battery cell in the Y direction, or can be located on different sides of the solid-state battery cell in the Y direction. Figure 1 In the non-limiting embodiments shown, the first composite groove and the second composite groove are located on the same side edge of the solid-state battery cell extending in the X direction.

[0149] When these two composite grooves are located on different sides of the solid-state battery cell in the Y direction, correspondingly, the positive tab and the negative tab are located on different sides of the solid-state battery cell. At this time, by providing an active expansion region in the solid-state battery cell, the effect of improving the volumetric energy density is more significant.

[0150] In some embodiments, the first composite groove and the second composite groove are located on the same side edge of the solid-state battery cell extending in the X direction. That is, in the Y direction, the first composite groove and the second composite groove are located on the same side of the solid-state battery cell.

[0151] In some embodiments, the first composite groove and the second composite groove are located at different side edges of the solid-state battery cell extending in the X direction. That is, in the Y direction, the first composite groove and the second composite groove are located on different sides of the solid-state battery cell.

[0152] In some embodiments, H N is equal to H0. At this time, the space at the tab can be utilized as much as possible to arrange the electrode active material layer, so as to improve the volumetric energy density of the solid-state battery cell and the solid-state battery as much as possible.

[0153] The utilization rate ψ of the active expansion region in the Y direction can be Y = H Δ / H0×100%.

[0154] In some embodiments, the solid-state battery cell satisfies one or more of the following characteristics:

[0155] H Δ ≥0.05 mm, optionally, 0.05 mm ≤ H Δ ≤1 mm;

[0156] ψ Y ≥0.05%, optionally, ψ Y ≥0.1%, further optionally, 0.1% ≤ ψ Y ≤2%.

[0157] Non-limitingly, H Δ ≥0.05 mm, optionally, 0.05 mm ≤ H Δ ≤1 mm. Non-limitingly, H Δ can also be any of the following values, or selected from the intervals formed by any two of the following values: 0.05 mm, 0.06 mm, 0.08 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1 mm, etc.

[0158] Non-limitingly, ψ Y ≥0.05%, optionally, ψ Y ≥0.1%, further optionally, 0.1% ≤ ψ Y ≤2%. Non-limitingly, ψ Y can also be any of the following percentages, or selected from the intervals formed by any two of the following percentages: 0.05%, 0.06%, 0.08%, 0.1%, 0.2%, 0.4%, 0.5%, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.5%, 1.6%, 1.8%, 2%, etc. Non-limitingly, ψ Y can also be any of the following ranges: 0.05% ≤ ψY ≤2% etc.

[0159] By adjusting one or both of the height parameter h Δ and the utilization rate parameter ψ Y within the aforementioned range, it is beneficial to better utilize the space in the height direction at the tab position.

[0160] The width of the solid-state battery cell in the X direction can be denoted as W0, and the width of the active expansion region in the X direction can be denoted as W Δ , and the utilization rate ψ of the active expansion region in the X direction X = W Δ / W0 × 100%.

[0161] In some embodiments, the solid-state battery cell satisfies one or more of the following characteristics:

[0162] W Δ ≥50 mm, optionally, 50 mm ≤ W Δ ≤1000 mm;

[0163] ψ X ≥60%, optionally, ψ X ≥70%, further optionally, 70% ≤ ψ X ≤95%.

[0164] Non-limitingly, W Δ ≥50 mm, optionally, 50 mm ≤ W Δ ≤1000 mm. Non-limitingly, W Δ can also be any of the following values, or selected from the intervals formed by any two of the following values: 50 mm, 60 mm, 80 mm, 100 mm, 120 mm, 150 mm, 200 mm, 250 mm, 300 mm, 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, 900 mm, 1000 mm, etc.

[0165] Non-limitingly, ψ X ≥60%, optionally, 60% ≤ ψ X ≤95%. Non-limitingly, ψ X can also be any of the following percentages, or selected from the intervals formed by any two of the following percentages: 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, etc., for example ψ X can be selected from the following range: ψ X ≥70%, 70% ≤ ψ X ≤95% etc.

[0166] By adjusting the width parameter w of the active expansion region Δand the utilization rate parameter ψ X When one or both of the regulations in X are within the foregoing ranges, it is beneficial to better utilize the space in the width direction at the tab position.

[0167] In this application, the projected area of the solid-state battery cell in the Z direction is denoted as A0, and the projected area of the active expansion region in the Z direction is denoted as A Δ , and the two-dimensional utilization rate ψ of the active expansion region A = A Δ / A0×100%.

[0168] In this application, unless otherwise specified, the "projected area of the solid-state battery cell in the Z direction" refers to the projected area of the electrode body part in the Z direction, excluding the projected area of the tab part in the Z direction.

[0169] In some embodiments, the solid-state battery cell satisfies: ψ A ≥0.04%.

[0170] In some embodiments, the solid-state battery cell satisfies: ψ A ≥0.05%.

[0171] In some embodiments, the solid-state battery cell satisfies: 0.04% ≤ ψ A ≤1.5%.

[0172] Non-limitingly, ψ A can also be any of the following percentages, or selected from the intervals formed by any two of the following percentages: 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.16%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.2%, 1.4%, 1.5%, etc. For example, ψ A can be selected from the following ranges: 0.05% - 1.5%, 0.06% - 1.5%, 0.1% - 1.5%, 0.15% - 1.5%, 0.04% - 1.2%, 0.05% - 1.2%, 0.06% - 1.2%, 0.1% - 1.2%, 0.15% - 1.2%, 0.16% - 1.5%, 0.16% - 1.2%, etc.

[0173] By regulating the two-dimensional utilization rate ψ of the active expansion region A within the foregoing ranges, it is beneficial to better comprehensively utilize the idle space at the tab. It can be understood that, compared with the solid-state battery cell without an active expansion region, the percentage increase in the volume energy density of the solid-state battery cell with an active expansion region is usually higher than ψ A .

[0174] In some embodiments, the length of the positive electrode tab in the Y direction in the extended state is greater than the height of the first composite groove in the Y direction. In some of these embodiments, the positive electrode tab includes a positive electrode tab bending portion located within the first composite groove.

[0175] In some embodiments, the length of the negative electrode tab in the Y direction in the extended state is greater than the height of the second composite groove in the Y direction. In some of these embodiments, the negative electrode tab includes a negative electrode tab bending portion located within the second composite groove.

[0176] In some embodiments, the length of the positive electrode tab in the Y direction in the extended state is greater than the height of the first composite groove in the Y direction, and the length of the negative electrode tab in the Y direction in the extended state is greater than the height of the second composite groove in the Y direction.

[0177] In some embodiments, the positive electrode tab includes a positive electrode tab bending portion located within the first composite groove; the negative electrode tab includes a negative electrode tab bending portion located within the second composite groove.

[0178] In some embodiments, the positive electrode tab includes a positive electrode tab bending portion located within the first composite groove, and the length of the positive electrode tab in the Y direction in the extended state is greater than the height of the first composite groove in the Y direction;

[0179] The negative electrode tab includes a negative electrode tab bending portion located within the second composite groove, and the length of the negative electrode tab in the Y direction in the extended state is greater than the height of the second composite groove in the Y direction.

[0180] By reserving a certain extension height for the positive electrode tab or the negative electrode tab, it is convenient to use it as a flexible tab to connect to a rigid tab in subsequent processes. At least a part of each of the positive electrode tab and / or the negative electrode tab in the solid-state battery cell can be bent inward into the corresponding composite groove. With sufficient height reserved for the positive and negative electrode tabs, it is beneficial to further increase the volume occupancy rate of the electrode portion in the solid-state battery cell, and can significantly improve the volume energy density of the solid-state battery cell and the solid-state battery.

[0181] In the present application, the extension height of the positive electrode tab in the Y direction is denoted as H PJ . When the positive electrode tab and the negative electrode tab are on the same side in the height direction of the solid-state battery cell, in some embodiments, H PJ ≥H Δ , optionally, H PJ >H Δ .

[0182] In the present application, the extension height of the negative electrode tab in the Y direction is denoted as H NJ . When the positive electrode tab and the negative electrode tab are on the same side in the height direction of the solid-state battery cell, in some embodiments, H NJ≥H Δ , optionally, H NJ >H Δ .

[0183] In the process of preparing the positive electrode tab or the negative electrode tab, when coating the electrode paste on the corresponding current collector film, by controlling the coating height in the Y direction to be less than the height of the current collector film, after drying and die-cutting, the extended height of the formed tab can be greater than the height of the corresponding groove. It can be understood that a positive electrode tab is formed at the positive electrode tab groove by using the positive electrode paste and the positive electrode current collector film; a negative electrode tab is formed at the negative electrode tab groove by using the negative electrode paste and the negative electrode current collector film.

[0184] In the present application, unless otherwise specified, the "extended height of the tab" refers to the height of the tab in the Y direction in the extended state.

[0185] In some embodiments, the width of the positive electrode tab portion in the X direction is less than the width of the first composite groove in the X direction.

[0186] In some embodiments, the width of the negative electrode tab portion in the X direction is less than the width of the second composite groove in the X direction.

[0187] In some embodiments, the width of the positive electrode tab portion in the X direction is less than the width of the first composite groove in the X direction; the width of the negative electrode tab portion in the X direction is less than the width of the second composite groove in the X direction.

[0188] By leaving a certain gap at the two side edges of the corresponding tab portion at the composite groove, a suitable movement space can be reserved for the tab portion, and it also allows the positive and negative electrode tab portions to be bent into the composite groove more conveniently.

[0189] In some embodiments, in the X direction, there is a gap between the positive electrode tab portion and the two side edges of the first composite groove, and there is a gap between the negative electrode tab portion and the two side edges of the second composite groove. Non-limitingly, the width of any gap in the X direction can be independently 10 μm to 5000 μm, and can be independently selected as 0.1 mm to 1 mm, but not limited thereto. The width of any gap in the X direction can be independently any one of the following values or selected from the intervals formed by any two of the following values: 10 μm, 50 μm, 100 μm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, etc. For example, it can be selected from the following ranges: 0.2 mm to 1 mm, 0.15 mm to 1 mm, 0.3 mm to 1 mm, 0.2 mm to 0.5 mm, 0.15 mm to 0.5 mm, 0.3 mm to 0.5 mm, etc.

[0190] By controlling the size of the above-mentioned gap within a more appropriate range, it is possible to prevent the positive and negative electrode tabs from scratching against adjacent structural layers in their different states, and at the same time, it is beneficial to maximize the proportion of the expanded active area.

[0191] In some embodiments, the solid-state battery cell has a laminated structure.

[0192] Non-limitingly, the size of the solid-state battery cell can be various sizes in known applicable fields, and can include, but is not limited to, the size specifications of battery products such as button batteries and notebook batteries.

[0193] In some embodiments, the solid electrolyte part includes at least one layer of solid electrolyte layer. It can be understood that a solid electrolyte layer is provided between any adjacent positive electrode layer and negative electrode layer. Therefore, the number of solid electrolyte layers in the solid electrolyte part matches the number of electrode layers in the electrode part.

[0194] In some embodiments, the positive electrode body includes at least one layer of positive electrode layer, and each positive electrode layer is provided with grooves corresponding to the first composite groove and the second composite groove respectively. A positive electrode tab is provided at the groove corresponding to the first composite groove in at least one layer of positive electrode layer;

[0195] The negative electrode body includes at least one layer of negative electrode layer, and each negative electrode layer is provided with grooves corresponding to the second composite groove and the first composite groove respectively. A negative electrode tab is provided at the groove corresponding to the second composite groove in at least one layer of negative electrode layer;

[0196] The solid electrolyte part includes at least one layer of solid electrolyte layer, and any adjacent positive electrode layer and negative electrode layer are isolated by the solid electrolyte layer; each solid electrolyte layer is provided with empty grooves corresponding to the first composite groove and the second composite groove respectively.

[0197] In this application, unless otherwise specified, the groove corresponding to the first composite groove in the positive electrode layer is denoted as the "positive electrode tab groove". The positive electrode tab groove can be provided with a positive electrode tab or can be an empty groove, but at least one positive electrode tab groove is provided with a positive electrode tab. It can be understood that the grooves corresponding to the second composite groove in the positive electrode layer are all empty grooves.

[0198] In this application, unless otherwise specified, the groove corresponding to the second composite groove in the negative electrode layer is denoted as the "negative electrode tab groove". The negative electrode tab groove can be provided with a negative electrode tab or can be an empty groove, but at least one negative electrode tab groove is provided with a negative electrode tab. It can be understood that the grooves corresponding to the first composite groove in the negative electrode layer are all empty grooves.

[0199] In this application, unless otherwise specified, an "empty groove" includes a groove in the electrode layer where no tab is provided, and also includes a groove in the solid electrolyte layer corresponding to two composite grooves. The empty grooves involved in this application at least include a first empty groove in the positive electrode layer corresponding to the second composite groove, a second empty groove in the negative electrode layer corresponding to the first composite groove, a fourth empty groove in the solid electrolyte layer corresponding to the first composite groove, and a third empty groove in the solid electrolyte layer corresponding to the second composite groove.

[0200] In some embodiments, the positive electrode body includes at least one layer of positive electrode layer. Each positive electrode layer independently includes a positive electrode current collector layer and a positive electrode active material layer located on at least one side of the positive electrode current collector layer. Each positive electrode layer is provided with a positive electrode tab groove. All the positive electrode tab grooves in the positive electrode body together form a part of the first composite groove. The positive electrode current collector layer in at least one layer of positive electrode layer is connected with a positive electrode tab at the corresponding positive electrode tab groove. All the positive electrode tabs connected by the positive electrode body together form at least a part of the positive electrode tab portion.

[0201] The negative electrode body includes at least one layer of negative electrode layer. Each negative electrode layer independently includes a negative electrode current collector layer and a negative electrode active material layer located on at least one side of the negative electrode current collector layer. Each negative electrode layer is provided with a negative electrode tab groove. All the negative electrode tab grooves in the negative electrode body together form a part of the first composite groove. The negative electrode current collector layer in at least one layer of negative electrode layer is connected with a negative electrode tab at the corresponding negative electrode tab groove. All the negative electrode tabs connected by the negative electrode body together form at least a part of the negative electrode tab portion.

[0202] In this application, unless otherwise specified, a "positive electrode tab groove" refers to a groove in the positive electrode layer corresponding to the position of the positive electrode tab portion. For any positive electrode layer, a positive electrode tab may or may not be provided at the positive electrode tab groove, as long as the number of positive electrode tabs connected by all positive electrode layers is greater than or equal to 1.

[0203] In this application, unless otherwise specified, a "negative electrode tab groove" refers to a groove in the negative electrode layer corresponding to the position of the negative electrode tab portion. For any negative electrode layer, a negative electrode tab may or may not be provided at the negative electrode tab groove, as long as the number of negative electrode tabs connected by all negative electrode layers is greater than or equal to 1.

[0204] In the thickness direction of the positive electrode layer, the positive electrode active material layer can be located on at least one side of the positive electrode current collector layer. The positive electrode active material layer can be located only on one side of the positive electrode current collector layer, or positive electrode active material layers can be provided on both sides of the positive electrode current collector. In some embodiments, the thickness direction of the positive electrode layer is consistent with the Z direction.

[0205] In the thickness direction of the negative electrode layer, the negative electrode active material layer can be located on at least one side of the negative electrode current collector layer. The negative electrode active material layer can be located only on one side of the negative electrode current collector layer, or the negative electrode active material layer can be provided on both sides of the negative electrode current collector. In some embodiments, the thickness direction of the negative electrode layer is consistent with the Z direction.

[0206] Non-limitingly, the positive electrode tab can be made of the same material as the positive electrode current collector layer. Further, the positive electrode tab can be derived from the same current collector film material as the positive electrode current collector layer. Such positive electrode tabs can be classified as "soft tabs".

[0207] Non-limitingly, the negative electrode tab can be made of the same material as the negative electrode current collector layer. Further, the negative electrode tab can be derived from the same current collector film material as the negative electrode current collector layer. Such negative electrode tabs can be classified as "soft tabs".

[0208] When the solid-state battery cell adopts the aforementioned stacked structure, at the first composite groove, the positive electrode tab groove on the positive electrode layer, the empty groove on the negative electrode layer, and the empty groove on the solid electrolyte layer can be used to form a concave space for the positive electrode tab to bend inward; at the second composite groove, the negative electrode tab groove on the negative electrode layer, the empty groove on the positive electrode layer, and the empty groove on the solid electrolyte layer can be used to form a concave space for the negative electrode tab to bend inward.

[0209] In some embodiments, all the positive electrode tabs connected to the positive electrode body together constitute at least a part of the positive electrode tab portion. At this time, the positive electrode tab portion can further include a positive electrode hard tab portion.

[0210] In some embodiments, all the positive electrode tabs connected to the positive electrode body together constitute the positive electrode tab portion.

[0211] In some embodiments, all the negative electrode tabs connected to the negative electrode body together constitute at least a part of the negative electrode tab portion. At this time, the negative electrode tab portion can further include a negative electrode hard tab portion.

[0212] In some embodiments, all the negative electrode tabs connected to the negative electrode body together constitute the negative electrode tab portion.

[0213] In some embodiments, the number of layers of the positive electrode layer in the positive electrode body is a single layer; the number of layers of the negative electrode layer in the negative electrode body is a single layer.

[0214] In some embodiments, the number of layers of the positive electrode layer in the positive electrode body is multiple layers; the number of layers of the negative electrode layer in the negative electrode body matches the number of layers of the positive electrode layer in the positive electrode body.

[0215] When the number of layers of the positive electrode layer in the positive electrode body is multiple layers and the number of layers of the negative electrode layer in the negative electrode body is a corresponding multiple layers, the stacked structure corresponds to a multi-layer stacked structure. At this time, using the aforementioned active expansion region structure design is beneficial to increase the volumetric energy density at the tab space.

[0216] Non - restrictively, the number of positive electrode layers in the positive electrode body can be one or more. The more the number of positive electrode layers in the positive electrode body, the thicker the battery. The appropriate number of positive electrode layers can be selected according to the size requirements of the solid - state battery.

[0217] Based on the number of positive electrode layers in the positive electrode body, the number of positive electrode layers can be one or more. Generally, the number of negative electrode layers in the negative electrode body is not less than the number of positive electrode layers in the positive electrode body.

[0218] In some embodiments, the number of positive electrode layers in the positive electrode body is equal to the number of negative electrode layers in the negative electrode body.

[0219] In some embodiments, the number of positive electrode layers N in the positive electrode body P ≥1, optionally, N P ≥2, further optionally, N P ≥5, still further optionally, N P ≥10, still further optionally, N P ≥20, still further optionally, N P ≥30, still further optionally, N P ≥40, still further optionally, N P ≥50. Non - restrictively, the number of positive electrode layers N in the positive electrode body P is 1 - 60, and can be 2 - 60. The number of positive electrode layers N in the positive electrode body P can also be any one of the following values or an interval composed of any two of the following values: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, etc.

[0220] In some embodiments, the number of positive electrode layers in the positive electrode body is 1.

[0221] In some embodiments, a plurality of positive electrode layers in the positive electrode body are connected to a positive electrode tab; a plurality of negative electrode layers in the negative electrode body are connected to a negative electrode tab.

[0222] In this application, unless otherwise specified, when a plurality of positive electrode layers in the positive electrode body are all connected to a positive electrode tab, the plurality of positive electrode tabs are stacked in the Z - direction to form a positive electrode tab part with a multi - layer structure. At this time, the "positive electrode tab part" can also be denoted as a positive electrode tab laminate.

[0223] In the present application, unless otherwise specified, when multiple negative electrode layers in the negative electrode body are all connected to negative electrode tabs, the multiple negative electrode tabs are stacked in the Z direction to form a negative electrode tab portion with a multi-layer structure. At this time, the "negative electrode tab portion" can also be denoted as a negative electrode tab laminate.

[0224] When multiple positive electrode layers in the positive electrode body are all connected to positive electrode tabs and multiple negative electrode layers in the negative electrode body are all connected to negative electrode tabs, it is more conducive to saving the waste of the internal space of the casing caused by the stacking of multiple electrode tabs.

[0225] In the solid-state battery cell, the positive electrode layer is further provided with an empty groove corresponding to the second composite groove, which can be denoted as the first empty groove; the negative electrode layer is further provided with an empty groove corresponding to the first composite groove, which can be denoted as the second empty groove; the solid electrolyte layer is provided with empty grooves corresponding to the first composite groove and the second composite groove respectively. The empty groove corresponding to the first composite groove can be denoted as the fourth empty groove, and the empty groove corresponding to the second composite groove can be denoted as the third empty groove.

[0226] In the solid-state battery cell, the positive electrode tab groove, the fourth empty groove, and the second empty groove are matched in position to provide a first composite groove for accommodating at least a part of the positive electrode tab portion, and the negative electrode tab groove, the third empty groove, and the first empty groove are matched in position to provide a second composite groove for accommodating at least a part of the negative electrode tab portion.

[0227] In some embodiments, the present application provides a solid-state battery cell, which includes a stacked positive electrode portion, a solid electrolyte portion, and a negative electrode portion. The positive electrode portion and the negative electrode portion are separated by the solid electrolyte portion; the positive electrode portion includes a positive electrode body and a positive electrode tab connected to the positive electrode body, and the negative electrode portion includes a negative electrode body and a negative electrode tab connected to the negative electrode body;

[0228] The positive electrode body includes at least one positive electrode layer, and at least one positive electrode layer is connected to a positive electrode tab. All the positive electrode tabs connected to the positive electrode body together form at least a part of the positive electrode tab portion; the negative electrode body includes at least one negative electrode layer, and at least one negative electrode layer is connected to a negative electrode tab. All the negative electrode tabs connected to the negative electrode body together form at least a part of the negative electrode tab portion;

[0229] At least one side edge extending in the X direction, the solid-state battery cell is provided with two composite grooves, which are respectively denoted as the first composite groove and the second composite groove; the first composite groove is used for accommodating at least a part of the positive electrode tab portion, and the second composite groove is used for accommodating at least a part of the negative electrode tab portion.

[0230] In some embodiments, the present application provides a solid-state battery cell, which includes a stacked positive electrode portion, a solid electrolyte portion, and a negative electrode portion. The positive electrode portion and the negative electrode portion are separated by the solid electrolyte portion; the positive electrode portion includes a positive electrode body and a positive electrode tab connected to the positive electrode body, and the negative electrode portion includes a negative electrode body and a negative electrode tab connected to the negative electrode body;

[0231] The positive electrode body includes a plurality of positive electrode layers, and each of the plurality of positive electrode layers is connected with a positive electrode tab. All the positive electrode tabs connected to the positive electrode body together form a positive electrode tab stack; the negative electrode body includes a plurality of negative electrode layers, and each of the plurality of negative electrode layers is connected with a negative electrode tab. All the negative electrode tabs connected to the negative electrode body together form a stack.

[0232] At least one side edge extending in the X direction, the solid-state battery cell is provided with two composite grooves, respectively denoted as a first composite groove and a second composite groove; the first composite groove is used to accommodate at least a part of the positive electrode tab portion, and the second composite groove is used to accommodate at least a part of the negative electrode tab portion.

[0233] In the present application, the "tab stack" includes a positive electrode tab stack and a negative electrode tab stack. It can be understood that the plurality of tabs in the tab stack are respectively connected to the corresponding electrode layers, and further, are respectively connected to the current collector layers in the corresponding electrode layers. The plurality of positive electrode tabs in the positive electrode tab stack are respectively connected to the corresponding positive electrode layers, and further, are respectively connected to the positive electrode current collector layers in the corresponding positive electrode layers. The plurality of negative electrode tabs in the negative electrode tab stack are respectively connected to the corresponding negative electrode layers, and further, are respectively connected to the negative electrode current collector layers in the corresponding negative electrode layers.

[0234] In a second aspect of the present application, there is provided a solid-state battery cell, which includes the solid-state battery cell described in the first aspect of the present application.

[0235] In a third aspect of the present application, there is provided a solid-state battery, which includes the solid-state battery cell described in the first aspect of the present application.

[0236] In some embodiments, the solid-state battery is an all-solid-state battery.

[0237] The solid-state battery cell and the solid-state battery including the aforementioned solid-state battery cell increase the volume of the electrode body at the tab height, improve the space occupancy rate of the electrode active material layer, and can greatly improve the volume energy density.

[0238] Non-limitingly, a prefabricated positive electrode sheet, a prefabricated solid electrolyte membrane sheet, and a prefabricated negative electrode sheet can be stacked in sequence, with the solid electrolyte membrane sheet placed between the positive electrode sheet and the negative electrode sheet, and the solid-state battery cell can be prepared by hot roll pressing.

[0239] In some embodiments, the solid-state battery cell can be prepared by a method including steps S100, S200, S300, and S400:

[0240] S100: Prepare a positive electrode sheet provided with a positive electrode tab groove and a first empty groove. The positive electrode sheet includes a positive electrode current collector layer, a positive electrode active material layer located on at least one side of the positive electrode current collector, and a positive electrode tab connected to the positive electrode current collector layer. The positive electrode tab is disposed at the positive electrode tab groove;

[0241] S200: Prepare a negative electrode tab, including a negative electrode current collector layer, a negative electrode active material layer located on at least one side of the negative electrode current collector, and a negative electrode tab connected to the negative electrode current collector layer. The negative electrode tab is disposed at the negative electrode tab groove.

[0242] S300: Prepare a solid electrolyte membrane provided with a third empty groove and a fourth empty groove.

[0243] S400: Stack the positive electrode tab, the solid electrolyte membrane, and the negative electrode tab in the order of "negative electrode tab - solid electrolyte membrane - positive electrode tab - solid electrolyte membrane" to obtain a stacked body, align the profiles of the positive electrode tab groove, the fourth empty groove, and the second empty groove to form a first composite groove, and align the profiles of the negative electrode tab groove, the third empty groove, and the first empty groove to form a second composite groove. All the positive electrode tabs provided by the positive electrode tab are disposed at the first composite groove and together constitute at least a part of the positive electrode tab portion. All the negative electrode tabs provided by the negative electrode tab are disposed at the second composite groove and together constitute at least a part of the negative electrode tab portion. Perform hot roll pressing on the stacked body to prepare a solid-state battery cell. Wherein, each positive electrode tab constitutes a positive electrode portion, each negative electrode tab constitutes a negative electrode portion, and each solid electrolyte membrane constitutes a solid electrolyte portion.

[0244] Based on the number of positive electrode tabs, the number of stacked positive electrode tabs can be one or more. Generally, the number of stacked negative electrode tabs is not less than the number of stacked positive electrode tabs.

[0245] In some embodiments, the number of stacked positive electrode tabs is equal to the number of stacked negative electrode tabs.

[0246] In some embodiments, the number of stacked positive electrode tabs is multiple; the profiles of multiple positive electrode tabs of the multiple positive electrode tabs are aligned and together constitute a positive electrode tab stacked body, at least a part of the positive electrode tab stacked body is received in the first composite groove, the profiles of multiple negative electrode tabs of the multiple negative electrode tabs are aligned and together constitute a negative electrode tab stacked body, and at least a part of the negative electrode tab stacked body is received in the second composite groove.

[0247] In this application, unless otherwise specified, the "empty groove" in the positive electrode sheet, negative electrode sheet, and solid electrolyte film refers to the space of the corresponding groove being reserved before being assembled into a solid-state battery cell. After being assembled into a battery cell, it can participate in forming a composite groove to provide a space for matching the pole ear. For example, in some embodiments, the positive electrode sheet for forming the positive electrode layer, in addition to having a positive electrode ear groove matching the position of the positive electrode ear, also reserves a first empty groove for matching the position of the negative electrode ear in the solid-state battery cell; the negative electrode sheet for forming the negative electrode layer, in addition to having a negative electrode ear groove matching the position of the negative electrode ear, also reserves a second empty groove for matching the position of the positive electrode ear in the solid-state battery cell; the solid electrolyte film for forming the solid electrolyte layer reserves a third empty groove for matching the position of the negative electrode ear in the solid-state battery cell and a fourth empty groove for matching the position of the positive electrode ear in the solid-state battery cell.

[0248] In the application, among the "first empty groove", "second empty groove", "third empty groove", and "fourth empty groove", the terms "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", and "fourth" only serve the purpose of non-exhaustive enumerative description and should be understood not to constitute a closed limitation on quantity.

[0249] In some embodiments, the solid-state battery cell can be prepared by a method including steps S100, S200, S300, and S400:

[0250] S100: Prepare a positive electrode sheet having a positive electrode ear groove and a first empty groove. The positive electrode sheet includes a positive electrode current collector layer, a positive electrode active material layer located on at least one side of the positive electrode current collector, and a positive electrode ear connected to the positive electrode current collector layer. The positive electrode ear is disposed at the positive electrode ear groove;

[0251] S200: Prepare a negative electrode sheet having a negative electrode ear groove and a second empty groove. The negative electrode sheet includes a negative electrode current collector layer, a negative electrode active material layer located on at least one side of the negative electrode current collector, and a negative electrode ear connected to the negative electrode current collector layer. The negative electrode ear is disposed at the negative electrode ear groove;

[0252] S300: Prepare a solid electrolyte film having a third empty groove and a fourth empty groove;

[0253] S400: Stack multiple positive electrode plates, multiple solid electrolyte membrane plates, and multiple negative electrode plates in sequence according to the order of "negative electrode plate - solid electrolyte membrane plate - positive electrode plate - solid electrolyte membrane plate" to obtain a stacked body, align the profiles of the positive electrode tab grooves, the fourth empty grooves, and the second empty grooves to form a first composite groove, and align the profiles of the negative electrode tab grooves, the third empty grooves, and the first empty grooves to form a second composite groove; align the multiple positive electrode tabs of the multiple positive electrode plates and jointly form a positive electrode tab stacked body, at least a part of the positive electrode tab stacked body is accommodated at the first composite groove, align the multiple negative electrode tabs of the multiple negative electrode plates and jointly form a negative electrode tab stacked body, at least a part of the negative electrode tab stacked body is accommodated at the second composite groove; perform hot roll pressing on the stacked body to prepare a solid-state battery cell.

[0254] In some embodiments, the method for preparing a solid-state battery cell further includes one or both of step S500 and step S600:

[0255] S500: Bend at least a part of the positive electrode tab into the first composite groove to obtain a bent portion of the positive electrode tab in the first composite groove;

[0256] S600: Bend at least a part of the negative electrode tab into the second composite groove to obtain a bent portion of the negative electrode tab in the second composite groove.

[0257] Those skilled in the art can understand that in the methods of each embodiment or example, the writing order of each step does not mean a strict execution order that constitutes any limitation to the implementation process, and the detailed execution order of each step should be determined by its function and possible internal logic. If there is no special instruction, all steps of this application can be carried out in sequence or randomly, and preferably in sequence. For example, method M includes steps (a) and (b), indicating that this method can include steps (a) and (b) carried out in sequence, or can also include steps (b) and (a) carried out in sequence. For example, method M may further include step (c), indicating that step (c) can be added to method M in any order. For example, method M can include steps (a), (b), and (c), or can also include steps (a), (c), and (b), or can also include steps (c), (a), and (b), etc.

[0258] The positive electrode tab grooves in the positive electrode plates, the negative electrode tab grooves in the negative electrode plates, the third empty grooves and the fourth empty grooves in the solid electrolyte membrane plates can all be prepared by laser cutting technology.

[0259] Taking the preparation of the positive electrode plate by the wet method as an example, a method including the following steps can be used to prepare a positive electrode plate provided with a positive electrode tab groove and a first empty groove:

[0260] S12: Coat the positive electrode paste on a preset area on at least one surface of the positive electrode current collector film, leave concave blank areas at preset positions of the positive electrode tab groove and the first empty groove, and after drying, form a positive electrode active material layer with an inner concave blank area, obtaining a positive electrode multilayer body including a positive electrode current collector and a positive electrode active material layer with an inner concave blank area;

[0261] S14: Use laser cutting technology to die-cut the positive electrode current collector film to obtain a positive electrode current collector layer matching the shape of the positive electrode active material layer, form a positive electrode tab connected to the positive electrode current collector layer at a preset position of the positive electrode tab groove, and form a first empty groove at a preset position of the first empty groove. Further, the positive electrode tab groove corresponds to a first composite groove in the solid-state battery cell that provides space for the positive electrode tab part, and the first empty groove corresponds to a second composite groove in the solid-state battery cell that accommodates at least a part of the negative electrode tab.

[0262] It can be understood that in step S12, the positive electrode paste is composed of the constituent raw materials and solvent of the positive electrode active material layer. After drying, the solvent is removed, and the remaining components form the corresponding positive electrode active material layer.

[0263] In step S12, the concave blank areas are not coated with the positive electrode paste. After drying, the formed positive electrode active area correspondingly has inner concave blank areas, and the inner concave contour of the inner concave blank areas can guide the die-cutting trajectory in the subsequent die-cutting step.

[0264] The positive electrode tab formed in step S14 generally belongs to the category of "soft tab".

[0265] In step S14, when die-cutting, the positive electrode current collector film at the positive electrode tab retains a part matching the width of the positive electrode tab groove, so that the positive electrode tab remains connected to the positive electrode current collector layer. That is, at this time, the positive electrode tab and the positive electrode current collector are integrated; in the width direction, both sides of the positive electrode tab are separated from the edge of the positive electrode current collector layer, enabling the positive electrode tab to be bent in a direction perpendicular to the surface of the positive electrode current collector film. Further, there is a gap between both sides of the positive electrode tab and the edge of the positive electrode current collector layer.

[0266] In step S14, when die-cutting, the positive electrode current collector film at the first empty groove is cut and removed. When assembling the solid-state battery cell subsequently, this first empty groove can correspond to the position of the negative electrode tab groove, enabling the negative electrode tab to be bent in a direction perpendicular to the surface of the negative electrode sheet. In addition, in a solid-state battery cell where the number of negative electrode layers of the negative electrode body is greater than 1 and the number of negative electrode tabs is greater than 1, there is no residue of the positive electrode current collector film between multiple negative electrode tabs in the negative electrode tab part.

[0267] Taking the preparation of the negative electrode sheet by the wet method as an example, a method including the following steps can be used to prepare a negative electrode sheet provided with a negative electrode tab groove and a second empty groove:

[0268] S22: Coating the negative electrode paste on a preset area on at least one surface of the negative electrode current collector film material, forming concave blank areas at preset positions of the negative electrode tab groove and the second empty groove, and drying to form a negative electrode active material layer with an inner concave blank area, obtaining a negative electrode multilayer body including a negative electrode current collector and a negative electrode active material layer with an inner concave blank area;

[0269] S24: Using laser cutting technology to die-cut the negative electrode current collector film material, obtaining a negative electrode current collector layer matching the shape of the negative electrode active material layer, forming a negative electrode tab connected to the negative electrode current collector layer at a preset position of the negative electrode tab groove, and forming a second empty groove at a preset position of the second empty groove. Further, the negative electrode tab groove corresponds to at least a part of the second composite groove in the solid-state battery cell for accommodating the negative electrode tab, and the second empty groove corresponds to at least a part of the first composite groove in the solid-state battery cell for accommodating the positive electrode tab.

[0270] It can be understood that in step S22, the negative electrode paste is composed of the constituent raw materials and solvents of the negative electrode active material layer. After drying, the solvents are removed, and the remaining components form the corresponding negative electrode active material layer.

[0271] In step S22, the concave blank area is not coated with the negative electrode paste. After drying, the formed negative electrode active area correspondingly has an inner concave blank area, and the inner concave contour of the inner concave blank area can guide the die-cutting trajectory in the subsequent die-cutting step.

[0272] The negative electrode tab formed in step S24 generally belongs to the category of "soft tab".

[0273] In step S24, when die-cutting, the negative electrode current collector film material at the negative electrode tab retains a part matching the width of the negative electrode tab groove, so that the negative electrode tab is connected to the negative electrode current collector layer; in the width direction, both sides of the negative electrode tab are separated from the edge of the negative electrode current collector layer, enabling the negative electrode tab to be bent in a direction perpendicular to the surface of the negative electrode current collector film material. Further, there is a gap between both sides of the negative electrode tab and the edge of the negative electrode current collector layer.

[0274] In step S24, when die-cutting, the negative electrode current collector film material at the second empty groove is cut and removed. When assembling the solid-state battery cell subsequently, the second empty groove can correspond to the position of the positive electrode tab groove, enabling the positive electrode tab to be bent in a direction perpendicular to the surface of the positive electrode plate. In addition, in a solid-state battery cell with more than 1 layer of positive electrode layer and more than 1 positive electrode tab in the positive electrode body, there is no residue of the negative electrode current collector film material between multiple positive electrode tabs in the positive electrode tabs.

[0275] Taking the preparation of a solid electrolyte membrane sheet as an example, a method including the following steps can be used to prepare a solid electrolyte membrane sheet provided with a third empty groove and a fourth empty groove:

[0276] S34: Use laser cutting technology to die-cut the solid electrolyte film material to obtain solid electrolyte film pieces that match the shapes of the positive electrode sheet and the negative electrode sheet. A fourth empty groove is formed at a preset position of the positive electrode tab in the positive electrode sheet, and a third empty groove is formed at a preset position of the negative electrode tab in the negative electrode sheet. Further, the fourth empty groove corresponds to a first composite groove in the solid-state battery cell for accommodating at least a part of the positive electrode ear portion, and the third empty groove corresponds to a second composite groove in the solid-state battery cell for accommodating at least a part of the negative electrode ear portion.

[0277] Non-limitingly, the solid electrolyte film material can be obtained by any suitable known method. For example, the constituent raw materials of the solid electrolyte film material (such as solid electrolyte powder) can be pressed into a film shape under pressure to obtain the solid electrolyte film material.

[0278] The solid-state battery includes at least one solid-state battery cell. The solid-state battery can include one or more solid-state battery cells.

[0279] In this application, unless otherwise specified, a "solid-state battery cell" refers to a basic unit capable of converting chemical energy and electrical energy into each other, and all its constituent components are in a solid state. In some embodiments, the solid-state battery cell can be a all-solid-state battery cell.

[0280] In this application, unless otherwise specified, an "all-solid-state battery cell" refers to a solid-state battery cell in which all the electrolytes in the battery are solid electrolytes. At this time, the positive electrode layer, the negative electrode layer, and the electrolyte part all use solid materials, and no liquid electrolyte is provided in the battery cell, so it can be called an "all-solid-state battery cell".

[0281] Non-limitingly, the solid-state battery cell (which can be an all-solid-state battery cell) can include a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, and the solid electrolyte layer is located between the positive electrode layer and the negative electrode layer. During the charging and discharging process of the battery, active ions are embedded and extracted back and forth between the positive electrode layer and the negative electrode layer. The solid electrolyte layer plays a role in conducting ions between the positive electrode layer and the negative electrode layer, and can also isolate the positive electrode layer from the negative electrode layer to prevent short circuit between the positive and negative electrodes.

[0282] In some embodiments, the solid-state battery cell 5 includes a solid-state battery core 52.

[0283] In some embodiments, the solid-state battery core is an all-solid-state battery core.

[0284] In some embodiments, the solid-state battery core 52 (which can be an all-solid-state battery core) includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer stacked in sequence.

[0285] In some embodiments, the solid-state battery can include an outer package. The outer package can be used to encapsulate the above-mentioned solid-state battery core.

[0286] In some embodiments, the outer package of the solid-state battery can be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc. The outer package of the solid-state battery can also be a soft package, such as a pouch soft package. The material of the soft package can be plastic. Further, non-limiting examples of the plastic can include one or more of polypropylene, polybutylene terephthalate, and polybutylene succinate, etc.

[0287] This application has no particular limitation on the shape of the solid-state battery cell, which can be cylindrical, square, or any other arbitrary shape. For example, Figure 3 is a solid-state battery cell 5 with a square structure as an example.

[0288] In some of these embodiments, referring to Figure 4 , the outer package can include a housing 51 and a cover plate 53. Among them, the housing 51 can include a bottom plate and side plates connected to the bottom plate, and the bottom plate and the side plates enclose to form a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the cover plate 53 can be covered on the opening to close the receiving cavity. The solid-state battery core 52 is encapsulated in the receiving cavity. The number of solid-state battery cores 52 contained in the solid-state battery cell 5 can be one or more, and those skilled in the art can select according to actual needs.

[0289] The solid-state battery can be a battery module 4 or a battery pack 1.

[0290] The battery module includes at least one solid-state battery cell. The number of solid-state battery cells contained in the battery module can be one or more, and those skilled in the art can select a suitable number according to the application and capacity of the battery module.

[0291] Figure 5 is a battery module 4 as an example. Referring to Figure 5 , in the battery module 4, multiple solid-state battery cells 5 can be arranged in sequence along the length direction of the battery module 4. Of course, they can also be arranged in any other arbitrary manner. Further, the multiple solid-state battery cells 5 can be fixed by fasteners.

[0292] Optionally, the battery module 4 can further include a housing with a receiving space, and multiple solid-state battery cells 5 are accommodated in the receiving space.

[0293] In some of these embodiments, the above battery module can also be assembled into a battery pack. The number of battery modules contained in the battery pack can be one or more, and those skilled in the art can select a suitable number according to the application and capacity of the battery pack.

[0294] Figure 6 and Figure 7 is a battery pack 1 as an example. Referring to Figure 6 and Figure 7, in the battery pack 1, a battery box and a plurality of battery modules 4 disposed in the battery box can be included. The battery box includes an upper box body 2 and a lower box body 3. The upper box body 2 can cover the lower box body 3 and form a closed space for accommodating the battery modules 4. The plurality of battery modules 4 can be arranged in the battery box in any manner.

[0295] In the fourth aspect of the present application, an electrical device is provided, which includes at least one of the solid-state battery cells described in the first aspect of the present application, the solid-state battery monomers described in the second aspect of the present application, and the solid-state batteries described in the third aspect of the present application.

[0296] In some embodiments, the electrical device includes at least one of the solid-state batteries provided in any of the embodiments of the present application.

[0297] Non-limitingly, the solid-state battery can be used as the power source of the electrical device or as the energy storage unit of the electrical device. The electrical device can include mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, etc., but is not limited thereto. Among them, the mobile device can be, for example, a mobile phone, a laptop computer, etc.; the electric vehicle can be, for example, a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, an electric motorcycle, an electric tool, etc., but is not limited thereto. The electrical device can also be applied to fields such as military equipment and aerospace, and can also be applied to energy storage power systems such as hydraulic, thermal, wind, and solar power stations.

[0298] As the electrical device, the solid-state battery can be selected according to its usage requirements.

[0299] Figure 8 Shown is an electrical device 6 as an example. The electrical device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. In order to meet the high-power and high-energy density requirements of the electrical device for the solid-state battery, a battery pack or a battery module can be adopted.

[0300] Another example of the device can be a mobile phone, a tablet computer, a laptop computer, etc. This device usually requires thin and light, and a solid-state battery can be used as the power source.

[0301] Hereinafter, some embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application. For those not specified in the embodiments in terms of techniques or conditions, they shall be carried out according to the description above, or according to the techniques or conditions described in the literature in the art, or according to the product instructions. For the reagents or instruments not specified in the manufacturer, they are all conventional products that can be obtained through commercial purchase, or can be synthesized by conventional methods from commercially available products.

[0302] In the following examples, the solid electrolyte layer, the solid electrolyte film, the positive current collector film material, the positive active material layer, the positive electrode sheet, the negative current collector film material, the negative active material layer, and the negative electrode sheet: their width directions are consistent with the width direction (X direction) of the solid-state battery cell, their height directions are consistent with the height direction (Y direction) of the solid-state battery cell, and their thickness directions are consistent with the thickness direction (Z direction) of the solid-state battery cell.

[0303] In the following examples, as a non-limiting example, a tab groove, a corresponding tab, and a reserved empty groove are provided at the same-side edge of the positive electrode sheet or the negative electrode sheet in the height direction of the electrode sheet. Correspondingly, a positive tab and a negative tab are provided on the same side in the height direction of the solid-state battery cell. When the positive tab and the negative tab are provided on different sides in the height direction of the solid-state battery cell in other embodiments, the utilization rate ψ of the active expansion region in the Y direction Y and the two-dimensional utilization rate ψ of the active expansion region A will be higher.

[0304] In the following examples, as a non-limiting example, the positive tab groove, the second empty groove, the fourth empty groove, and the first composite groove have the same shape and size in the X direction and the Y direction, the negative tab groove, the first empty groove, the third empty groove, and the second composite groove have the same shape and size in the X direction and the Y direction, and the positive tab groove and the negative tab groove also have substantially the same size in the X direction and the Y direction. For the above-mentioned grooves, the groove depth is equal to the groove height, the width direction of the groove is consistent with the X direction, the height or depth direction of the groove is consistent with the Y direction, and the thickness direction of the groove is consistent with the Z direction.

[0305] In the following examples, when preparing the positive electrode sheet and the negative electrode sheet, after die-cutting, the width of the positive tab and the width of the negative tab are respectively slightly smaller than the width of the corresponding groove. That is, in the width direction of the electrode sheet, there are gaps between the positive tab, the negative tab and the two side edges of the corresponding tab groove, and any one side gap is in the range of 10 μm to 5000 μm and in the range of 0.1 mm to 1 mm. Correspondingly, in the solid-state battery cell, there are gaps between the positive tab, the negative tab and the two side edges of the corresponding composite groove, and any one side gap is in the range of 10 μm to 5000 μm and in the range of 0.1 mm to 1 mm.

[0306] In the following examples, as a non-limiting example, the heights of both the positive tab and the negative tab are set to 15 mm.

[0307] In the following examples, as a non-limiting example, a solid-state battery cell with a laminated structure is used.

[0308] Example 1.

[0309] Reference Figure 2 to the schematic diagram of the preparation process of the positive electrode sheet and the negative electrode sheet shown.

[0310] (1) Preparation of the positive electrode sheet 100.

[0311] S12: Coating the positive electrode slurry on both side surfaces of the positive electrode current collector film material 111, reserving concave blank areas for the positive electrode tab groove 122 and the first empty groove 124 respectively, and drying to form a positive electrode active area 120 with a positive electrode inner concave blank area 121.

[0312] S14: Using laser cutting technology to die-cut the positive electrode current collector film material 111 to obtain a positive electrode current collector layer matching the shape of the positive electrode active area. The positive electrode active area corresponds to the positive electrode active material layer. A positive electrode tab 130 connected to the positive electrode current collector layer is formed at a preset position of the positive electrode tab groove 122, and a first empty groove 124 is formed at a preset position of the first empty groove. Further, the positive electrode tab groove 122 corresponds to a first composite groove 1302 in the solid-state battery cell 52 for accommodating a part of the positive electrode tab 1300, and the first empty groove 124 corresponds to a second composite groove 3302 in the solid-state battery cell 52 for accommodating a part of the negative electrode tab 3300.

[0313] (2) Preparation of the negative electrode sheet 300.

[0314] S22: Coating the negative electrode slurry on both side surfaces of the negative electrode current collector film material 311, reserving concave blank areas for the negative electrode tab groove 322 and the second empty groove 324 respectively, and drying to form a negative electrode active area 320 with a negative electrode inner concave blank area 321.

[0315] S24: Using laser cutting technology to die-cut the negative electrode current collector film material 311 to obtain a negative electrode current collector layer matching the shape of the negative electrode active area. The negative electrode active area corresponds to the negative electrode active material layer. A negative electrode tab 320 connected to the negative electrode current collector layer is formed at a preset position of the negative electrode tab groove 322, and a second empty groove 324 is formed at a preset position of the second empty groove. Further, the negative electrode tab groove 322 corresponds to a second composite groove 3302 in the solid-state battery cell 52 for accommodating a part of the negative electrode tab 3300, and the second empty groove 324 corresponds to a first composite groove 1302 in the solid-state battery cell 52 for accommodating a part of the positive electrode tab 1300.

[0316] (3) Preparation of the solid electrolyte membrane sheet.

[0317] S34: Use laser cutting technology to die-cut the solid electrolyte film material to obtain solid electrolyte film pieces that match the shapes of the positive electrode sheet and the negative electrode sheet. Reserve a fourth empty groove for the positive electrode tab in the positive electrode sheet and a third empty groove for the negative electrode tab in the negative electrode sheet. Further, the fourth empty groove corresponds to the first composite groove 1302 in the solid-state battery cell 52 for accommodating a part of the positive electrode tab portion 1300, and the third empty groove corresponds to the second composite groove 3302 in the solid-state battery cell 52 for accommodating a part of the negative electrode tab portion 3300.

[0318] (4) Assemble to obtain a solid-state battery cell, the structure of which can be referred to Figure 1 .

[0319] Stack the previously prepared positive electrode sheet 100, solid electrolyte film pieces, and negative electrode sheet 300 in sequence according to the order of "negative electrode sheet - solid electrolyte film piece - positive electrode sheet - solid electrolyte film piece" to obtain a stacked member, align the profiles of the positive electrode tab groove 122, the fourth empty groove, and the second empty groove to form the first composite groove 1302, and align the profiles of the negative electrode tab groove 322, the third empty groove, and the first empty groove to form the second composite groove 3302; align the positive electrode tabs 130 of the positive electrode sheet 100 to jointly form the positive electrode tab portion 1300, and a part of the positive electrode tab portion 1300 is accommodated in the first composite groove 1302. Align the negative electrode tabs 330 of the negative electrode sheet 300 to jointly form the negative electrode tab portion 3300, and a part of the negative electrode tab portion 3300 is accommodated in the second composite groove 3302; perform hot roll pressing on the stacked member to prepare the solid-state battery cell 52. The area of the positive electrode sheet 100 corresponding to the positive electrode active area provides the positive electrode layer 10, the area of the negative electrode sheet 300 corresponding to the negative electrode active area provides the negative electrode layer 30, and the solid electrolyte film piece provides the solid electrolyte layer 20. All the positive electrode layers in the solid-state battery cell jointly form the positive electrode body, and all the negative electrode layers in the solid-state battery cell jointly form the negative electrode body.

[0320] In this example, the number of positive electrode sheets in the stacked member is 5; multiple positive electrode layers in the solid-state battery cell jointly form the positive electrode body, and multiple negative electrode layers in the solid-state battery cell jointly form the negative electrode body.

[0321] In this example, the positive electrode tab portion includes multiple positive electrode tabs, corresponding to the positive electrode tab laminate; the negative electrode tab portion includes multiple negative electrode tabs, corresponding to the negative electrode tab laminate.

[0322] Weld the multiple positive electrode tabs of the positive electrode tab portion into a positive electrode soft tab and transfer to an aluminum hard tab; weld the multiple negative electrode tabs of the negative electrode tab portion into a negative electrode soft tab and transfer to a nickel hard tab. Pre-bend the positive electrode soft tab and place at least a part exceeding the first composite groove into the first composite groove; pre-bend the negative electrode soft tab and place at least a part exceeding the second composite groove into the second composite groove.

[0323] (5) Aluminum-plastic film encapsulation: Punch a pit in the aluminum-plastic film, place it overlapping with the solid-state battery cell, seal the edge of the aluminum-plastic film, and encapsulate the solid-state battery cell in the accommodation cavity within the housing to obtain a solid-state battery. The height of the solid-state battery cell is basically the same as the height of the accommodation cavity of the housing.

[0324] Examples 2 - 16: Change the size of the battery cell and / or the size of the groove. Refer to Table 1.

[0325] In Example 2, the method is basically the same as that in Example 1, except that the width of the battery cell is changed. Refer to Table 1.

[0326] In Example 3, the method is basically the same as that in Example 1, except that the width and height of the battery cell are changed. Refer to Table 1.

[0327] In Example 4, the method is basically the same as that in Example 1, except that the width of the battery cell and the height of the groove are changed. Refer to Table 1.

[0328] In Example 5, the method is basically the same as that in Example 1, except that the width of the battery cell and the height of the groove are changed. Refer to Table 1.

[0329] In Examples 6 - 7, the method is basically the same as that in Example 1, except that the height of the groove is changed. Refer to Table 1.

[0330] In Examples 8 - 9, 15 - 16, the method is basically the same as that in Example 1, except that the width of the battery cell and the height of the groove are changed. Refer to Table 1.

[0331] In Examples 10 - 13, the method is basically the same as that in Example 1, except that the width of the battery cell, the width of the groove, and the height of the groove are changed. Refer to Table 1.

[0332] In Example 14, the method is basically the same as that in Example 1, except that the width, height of the battery cell, and the height of the groove are changed. Refer to Table 1.

[0333] Example 17: The method is basically the same as that in Example 1, except that in step (4), the number of positive electrode plates in the laminate is 1, the positive electrode part only includes one positive electrode layer and one positive electrode tab, and this positive electrode tab is used as the positive electrode ear part to directly transfer to the aluminum rigid ear; the number of negative electrode plates in the laminate is 1, the negative electrode part only includes one negative electrode layer and one negative electrode tab, and this negative electrode tab is used as the negative electrode ear part to directly transfer to the nickel rigid ear.

[0334] Comparative Examples 1 - 17: Traditional process, without an active expansion area.

[0335] Comparative Examples 1-17 did not have an active expansion area based on Examples 1-17 respectively; when applying the positive electrode paste in step S12 of preparing the positive electrode sheet, the positive electrode paste was not applied to the height area corresponding to the positive electrode tab groove, that is, the area corresponding to the active expansion area of Examples 1-17 was not coated with the positive electrode paste. When die-cutting in step S14, the height of the positive electrode tab was kept unchanged, and the area of the positive electrode current collector film material not coated with the positive electrode paste was cut off; when applying the negative electrode paste in step S22 of preparing the negative electrode sheet, the negative electrode paste was not applied to the height area corresponding to the negative electrode tab groove, that is, the area corresponding to the active expansion area of Examples 1-17 was not coated with the negative electrode paste. When die-cutting in step S24, the height of the negative electrode tab was kept unchanged, and the area of the negative electrode current collector film material not coated with the negative electrode paste was cut off.

[0336] Analysis method:

[0337] I. Volume utilization improvement rate contributed by the active expansion area to the solid-state battery.

[0338] Volume utilization improvement rate: It can be estimated according to the percentage of the area of the active expansion area relative to the active area of the electrode sheet without the active expansion area.

[0339] According to the parameters in Table 1, it can be calculated by the following formula:

[0340] Volume utilization improvement rate = (W Δ ×H Δ ) / (W0×(H 0- H Δ )) × 100%.

[0341] The analysis results can be referred to Table 1.

[0342] II. Utilization rate parameters of the active expansion area

[0343] 1. The utilization rate of the active expansion area in the Y direction (the height direction of the solid-state battery cell) can be estimated by the following formula: ψ Y = H Δ / H0×100%.

[0344] 2. The utilization rate of the active expansion area in the X direction (the width direction of the solid-state battery cell) can be estimated by the following formula: ψ X = W Δ / W0×100%.

[0345] 3. The two-dimensional utilization rate of the active expansion area can be estimated by the following formula: ψ A = A Δ / A0×100%, where the projected area of the solid-state battery cell along the Z direction (the thickness direction of the solid-state battery cell) is denoted as A0, and the projected area of the active expansion area along the Z direction is denoted as A Δ , A0 = W0×H0, AΔ = H Δ × (W0 - W Δ ).

[0346] Analysis result:

[0347] Compared with Comparative Examples 1 - 17 without an active expansion region, the structural designs of Examples 1 - 17 can significantly improve the volume utilization rate of the solid-state battery, and thus can improve the volume energy density of the battery.

[0348] In Examples 1 - 16, taking the number of stacked layers of the positive electrode sheet = the number of positive electrode layers in the positive electrode body = 5 as an example, it can be understood that those skilled in the art can replace it with other required numbers of positive electrode layers according to the battery thickness, and the same or substantially the same effect of improving the volume energy density of the battery can be achieved, such as Example 17.

[0349] Table 1.

[0350]

[0351]

[0352] The above descriptions of each embodiment and example tend to emphasize the differences between each embodiment and example. Their similarities or similarities can be referred to each other. For the sake of brevity, they will not be elaborated herein. The technical features of the above-described embodiments and examples can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0353] It should be noted that this application is not limited to the above embodiments and examples. The above embodiments and examples are only examples. Embodiments and examples with the same composition and the same effect as the technical idea within the technical solution scope of this application are included in the technical scope of this application. The above-described embodiments and examples only represent several embodiments and examples of this application, and their descriptions are relatively detailed, but they should not be construed as a limitation of the patent scope. In addition, within the scope not departing from the gist of this application, various modifications that those skilled in the art can think of to the embodiments or examples, and other ways constructed by combining some constituent elements in the embodiments or examples are also included in the scope of this application.

Claims

1. A solid-state battery cell, characterized in that, It includes a stacked positive electrode part, a solid electrolyte part, and a negative electrode part, and the positive electrode part and the negative electrode part are isolated by the solid electrolyte part; the positive electrode part includes a positive electrode body and a positive electrode tab connected to the positive electrode body, and the negative electrode part includes a negative electrode body and a negative electrode tab connected to the negative electrode body; The height direction of the solid-state battery cell is denoted as the Y direction, the width direction is denoted as the X direction, and the thickness direction is denoted as the Z direction; the X direction, the Y direction, and the Z direction are perpendicular to each other; At least one side edge extending along the X direction, the solid-state battery cell is provided with two composite grooves, denoted as the first composite groove and the second composite groove respectively; the first composite groove is used to accommodate at least a part of the positive electrode tab, and the second composite groove is used to accommodate at least a part of the negative electrode tab.

2. The solid-state battery cell according to claim 1, wherein In the solid-state battery cell, the active area that is at the same height as the first composite groove and the second composite groove in the Y direction and is located outside the first composite groove and the second composite groove in the X direction is denoted as the active expansion area; The height of the positive electrode body at the active expansion area is higher than the height of the positive electrode body at the first composite groove, and the height of the negative electrode body at the active expansion area is higher than the height of the negative electrode body at the second composite groove; Denote the height of the positive electrode body in the Y direction as H P , denote the height of the negative electrode body in the Y direction as H N , denote the height of the solid-state battery cell in the Y direction as H0; denote the maximum height of the active expansion region in the Y direction as H Δ , satisfying H Δ >0; H P >(H0 - H Δ ) and H N >(H0 - H Δ ).

3. The solid-state battery cell according to claim 2, wherein H N is equal to H0.

4. The solid-state battery cell according to claim 2, wherein Utilization rate ψ of the active expansion region in the Y direction Y = H Δ / H0 × 100%; The solid-state battery cell satisfies one or more of the following characteristics: H Δ ≥ 0.05 mm; ψ Y ≥ 0.05%.

5. The solid-state battery cell according to claim 4, characterized in that, The solid-state battery cell satisfies one or more of the following characteristics: 0.05mm ≤ H Δ ≤ 1mm; 0.1% ≤ ψ Y ≤ 2%.

6. The solid-state battery cell according to any one of claims 1 to 5, characterized in that Let the width of the solid-state battery cell in the X direction be denoted as W0, and let the width of the active expansion region in the X direction be denoted as W Δ , and the utilization rate ψ of the active expansion region in the X direction X = W Δ / W0 × 100%; The solid-state battery cell satisfies one or more of the following characteristics: W Δ ≥50 mm; ψ X ≥60%.

7. The solid-state battery cell according to claim 6, characterized in that The solid-state battery cell satisfies one or more of the following characteristics: 50mm ≤ W Δ ≤ 1000mm; 60% ≤ ψ X ≤ 95%.

8. The solid-state battery cell according to any one of claims 1 to 5, characterized in that Let the projected area of the solid-state battery cell in the Z direction be denoted as A0, and the projected area of the active expansion region in the Z direction be denoted as A Δ , and the two-dimensional utilization rate ψ of the active expansion region A = A Δ / A0 × 100%; The solid-state battery cell satisfies: ψ A ≥ 0.04%.

9. The solid-state battery cell according to claim 8, wherein, The solid-state battery cell satisfies: 0.04% ≤ ψ A ≤ 1.5%.

10. The solid-state battery cell according to claim 1, wherein, The extension height of the positive electrode tab in the Y direction in the extended state is greater than the height of the first composite groove in the Y direction; The extension height of the negative electrode tab in the Y direction in the extended state is greater than the height of the second composite groove in the Y direction.

11. The solid-state battery cell according to claim 10, characterized in that, The positive electrode tab includes a positive electrode tab bending part located in the first composite groove, and the negative electrode tab includes a negative electrode tab bending part located in the second composite groove.

12. The solid-state battery cell according to any one of claims 1 to 5, characterized in that, The width of the positive electrode tab in the X direction is smaller than the width of the first composite groove in the X direction; the width of the negative electrode tab in the X direction is smaller than the width of the second composite groove in the X direction.

13. The solid-state battery cell according to claim 12, characterized in that, In the X direction, there are gaps between the positive electrode tab and the two side edges of the first composite groove, and there are gaps between the negative electrode tab and the two side edges of the second composite groove.

14. The solid-state battery cell according to any one of claims 1 to 5, characterized in that, The solid-state battery cell has a laminated structure.

15. The solid-state battery cell according to claim 14, wherein, The positive electrode body includes at least one layer of positive electrode layer, each positive electrode layer is provided with grooves respectively corresponding to the first composite groove and the second composite groove, and a positive electrode tab is provided at the groove corresponding to the first composite groove in at least one layer of positive electrode layer; The negative electrode body includes at least one layer of negative electrode layer, each negative electrode layer is provided with grooves respectively corresponding to the second composite groove and the first composite groove, and a negative electrode tab is provided at the groove corresponding to the second composite groove in at least one layer of negative electrode layer; The solid electrolyte part includes at least one layer of solid electrolyte layer, and any adjacent positive electrode layer and negative electrode layer are isolated by the solid electrolyte layer; each solid electrolyte layer is provided with empty grooves corresponding to the first composite groove and the second composite groove respectively.

16. The solid-state battery cell according to claim 15, wherein The positive electrode body includes at least one layer of positive electrode layer. Each positive electrode layer independently includes a positive electrode current collector layer and a positive electrode active material layer located on at least one side of the positive electrode current collector layer. The positive electrode layers are all provided with positive electrode tab grooves. All the positive electrode tab grooves in the positive electrode body together constitute a part of the first composite groove. The positive electrode current collector layer in at least one layer of the positive electrode layer is connected with a positive electrode tab at the corresponding positive electrode tab groove. All the positive electrode tabs connected to the positive electrode body together constitute at least a part of the positive electrode tab part. The negative electrode body includes at least one layer of negative electrode layer. Each negative electrode layer independently includes a negative electrode current collector layer and a negative electrode active material layer located on at least one side of the negative electrode current collector layer. The negative electrode layers are all provided with negative electrode tab grooves. All the negative electrode tab grooves in the negative electrode body together constitute a part of the first composite groove. The negative electrode current collector layer in at least one layer of the negative electrode layer is connected with a negative electrode tab at the corresponding negative electrode tab groove. All the negative electrode tabs connected to the negative electrode body together constitute at least a part of the negative electrode tab part.

17. The solid-state battery cell according to claim 16, wherein, The number of layers of the positive electrode layers in the positive electrode body is multiple; the number of layers of the negative electrode layers in the negative electrode body matches the number of layers of the positive electrode layers in the positive electrode body.

18. The solid-state battery cell according to claim 17, characterized in that, Multiple positive electrode layers in the positive electrode body are connected with the positive electrode tabs; multiple negative electrode layers in the negative electrode body are connected with the negative electrode tabs.

19. A solid-state battery cell, characterized in that, Including the solid-state battery cell according to any one of claims 1 to 18.

20. A solid-state battery, characterized in that, Including the solid-state battery cell according to any one of claims 1 to 18.

21. The solid-state battery according to claim 20, characterized in that, The solid-state battery is an all-solid-state battery.

22. An electrical device, characterized in that, Including at least one of the solid-state battery cell according to any one of claims 1 to 18, the solid-state battery cell monomer according to claim 19, and the solid-state battery according to claim 20 or 21.

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