Solid state battery

Abstract

The utility model discloses a solid-state battery and belongs to the technical field of batteries. The solid-state battery comprises a positive plate, a negative plate and a solid-state electrolyte layer, the positive plate comprises a positive current collector and a first active material layer, and the first active material layer is arranged on the positive current collector; the negative plate comprises a negative current collector and a second active material layer, and the second active material layer is arranged on the negative current collector; the length of the negative plate is greater than or equal to that of the positive plate, and the width of the negative plate is greater than or equal to that of the positive plate; the solid electrolyte layer is arranged between the positive plate and the negative plate, the length of the solid electrolyte layer is equal to that of the negative plate, and the width of the solid electrolyte layer is equal to that of the negative plate. According to the solid-state battery, the positive plate and the negative plate are completely separated through the solid-state electrolyte layer, so that the problem of short circuit caused by overlap joint of burrs on the positive plate and burrs on the negative plate can be better avoided, and the safety and the service life of the solid-state battery are better ensured.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and more particularly to solid-state batteries. Background Technology

[0002] In the production process of solid-state lithium batteries, positive and negative electrode sheets need to be cut from the roll material by die cutting to meet the required size or shape of the positive and negative electrode sheets.

[0003] However, during the die-cutting process, whether using metal die-cutting or laser die-cutting, burrs will inevitably be generated at the die-cutting edges of the positive and negative electrodes. After the positive and negative electrodes are bonded and assembled, the burrs at the die-cutting edges of the positive and negative electrodes are very likely to overlap and cause short circuits.

[0004] Currently, a solid electrolyte layer is usually placed between the positive and negative electrode plates to isolate them, which can, to some extent, prevent the burrs on the positive electrode plate from overlapping with the burrs on the negative electrode plate and causing short circuits.

[0005] However, since the aforementioned solid electrolyte layer usually cannot completely separate the positive and negative electrodes, the burrs on the positive electrode and the burrs on the negative electrode can still overlap, causing a short circuit and failing to guarantee the safety and lifespan of the solid lithium battery.

[0006] Solid-state batteries are urgently needed to address these issues. Utility Model Content

[0007] The purpose of this invention is to propose a solid-state battery that can better avoid short circuits between the positive and negative electrodes, thereby better ensuring the safety and lifespan of the solid-state lithium battery.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] Solid-state batteries, including:

[0010] A positive electrode sheet includes a positive current collector and a first active material layer, wherein the first active material layer is disposed on the positive current collector;

[0011] The negative electrode includes a negative current collector and a second active material layer, the second active material layer being disposed on the negative current collector; the length of the negative electrode is greater than or equal to the length of the positive electrode, and the width of the negative electrode is greater than or equal to the width of the positive electrode.

[0012] A solid electrolyte layer is disposed between the positive electrode and the negative electrode, wherein the length of the solid electrolyte layer is equal to the length of the negative electrode and the width of the solid electrolyte layer is equal to the width of the negative electrode.

[0013] As an optional embodiment, a first region and a second region are formed on at least one side of the positive current collector, the second region is disposed around the first region, the first active material layer is disposed on the first region, a first adhesive layer is disposed on the second region, and the inner edge of the first adhesive layer is connected to the first active material layer.

[0014] Alternatively, the thickness of the first adhesive layer may be equal to the thickness of the first active material layer.

[0015] As an optional solution, the positive current collector includes:

[0016] First insulating base film;

[0017] A first conductive layer is disposed on the first insulating base film to form the first region.

[0018] As an optional embodiment, the first insulating base film includes a first support portion and a second support portion, wherein the first support portion is provided with the first conductive layer, the second support portion is disposed around the first support portion, and the second support portion is formed with the second region.

[0019] As an alternative, the thickness of the second support portion is equal to the sum of the thickness of the first conductive layer and the thickness of the first support portion.

[0020] As an alternative, a third region and a fourth region are formed on at least one side of the negative electrode current collector, the fourth region is disposed around the third region, the second active material layer is disposed on the third region, the fourth region is provided with a second adhesive layer, and the inner edge of the second adhesive layer is connected to the second active material layer.

[0021] Alternatively, the thickness of the second adhesive layer may be equal to the thickness of the second active material layer.

[0022] As an optional solution, the negative electrode current collector includes:

[0023] Second insulating base film;

[0024] A second conductive layer is disposed on the second insulating base film to form the third region.

[0025] As an optional embodiment, the second insulating base film includes a third support portion and a fourth support portion, wherein the second conductive layer is disposed on the third support portion, the fourth support portion is disposed around the third support portion, and the fourth region is formed on the fourth support portion.

[0026] The beneficial effects of this utility model are as follows:

[0027] By setting a solid electrolyte layer between the positive and negative electrodes, the length of the negative electrode is greater than or equal to the length of the positive electrode, and the width of the negative electrode is greater than or equal to the width of the positive electrode. The length and width of the solid electrolyte layer are equal to the length and width of the negative electrode. In other words, the negative electrode completely covers the positive electrode, and the solid electrolyte layer completely covers the positive electrode. This effectively isolates the positive and negative electrodes, preventing short circuits caused by burrs on the positive and negative electrodes overlapping. This better ensures the safety and lifespan of the solid-state battery. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the solid-state battery provided in Embodiment 1 of this utility model;

[0029] Figure 2 This is a top view of the positive electrode sheet provided in Embodiment 1 of this utility model;

[0030] Figure 3 This is a schematic diagram of the positive electrode current collector provided in Embodiment 1 of this utility model;

[0031] Figure 4 This is a schematic diagram of the solid-state battery provided in Embodiment 2 of this utility model.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1-Positive electrode sheet; 11-Positive current collector; 111-First insulating base film; 1111-First support portion; 1112-Second support portion; 112-First conductive layer; 113-First region; 114-Second region; 12-First active material layer; 13-First adhesive layer;

[0034] 2-Negative electrode sheet; 211-Second insulating base film; 212-Second conductive layer; 22-Second active material layer; 23-Second adhesive layer;

[0035] 3-Solid electrolyte layer;

[0036] 41-Copper foil current collector; 42-Third active material layer. Detailed Implementation

[0037] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0038] Any feature disclosed in this specification, unless specifically stated otherwise, may be replaced by other equivalent or similar features. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features. Throughout this specification, the same reference numerals indicate the same elements.

[0039] To make the technical problem solved by this utility model, the technical solution adopted, and the technical effect achieved clearer, the technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0040] Currently, a solid electrolyte layer is typically placed between the positive and negative electrodes to isolate them, which can prevent short circuits caused by burrs on the positive and negative electrodes coming together to some extent. However, since the solid electrolyte layer cannot completely isolate the positive and negative electrodes, short circuits can still occur due to burrs on the positive and negative electrodes coming together, thus failing to guarantee the safety and lifespan of solid-state lithium batteries.

[0041] Example 1

[0042] Therefore, this embodiment proposes a solid-state battery that can better avoid short circuits, thereby better ensuring the safety and lifespan of the solid-state battery. In this embodiment, the solid-state battery can specifically be a lithium-ion solid-state battery.

[0043] Specifically, such as Figure 1 As shown, the solid-state battery includes a positive electrode 1, a negative electrode 2, and a solid electrolyte layer 3. The negative electrode 2 is stacked on one side of the positive electrode 1. The positive electrode 1 includes a positive current collector 11 and a first active material layer 12, with the first active material layer 12 disposed on the positive current collector 11. The negative electrode 2 includes a negative current collector and a second active material layer 22, with the second active material layer 22 disposed on the negative current collector. Furthermore, the length of the negative electrode 2 is greater than or equal to the length of the positive electrode 1, and the width of the negative electrode 2 is greater than or equal to the width of the positive electrode 1. The solid electrolyte layer 3 is disposed between the positive electrode 1 and the negative electrode 2. The length of the solid electrolyte layer 3 is equal to the length of the negative electrode 2, and the width of the solid electrolyte layer 3 is equal to the width of the negative electrode 2.

[0044] Compared to existing technologies, the solid-state battery in this embodiment changes the length / width relationship between the solid electrolyte layer 3, the positive electrode 1, and the negative electrode 2. By placing the solid electrolyte layer 3 between the positive electrode 1 and the negative electrode 2, the length of the negative electrode 2 is greater than or equal to the length of the positive electrode 1, and the width of the negative electrode 2 is greater than or equal to the width of the positive electrode 1. Furthermore, the length of the solid electrolyte layer 3 is equal to the length of the negative electrode 2, and the width of the solid electrolyte layer 3 is equal to the width of the negative electrode 2. In other words, the negative electrode 2 can completely cover the positive electrode 1, and the solid electrolyte layer 3 can completely cover the positive electrode 1. This effectively isolates the positive electrode 1 and the negative electrode 2, better preventing short circuits caused by burrs on the positive electrode 1 and the negative electrode 2 overlapping, thus better ensuring the safety and lifespan of the solid-state battery. Specifically, the burrs are metal burrs or powder burrs.

[0045] Specifically, such as Figure 1 As shown, since the solid electrolyte layer 3 is disposed between the positive electrode 1 and the negative electrode 2, that is, the solid electrolyte layer 3 can completely block the positive electrode 1 and the negative electrode 2 from the second direction and the inclined direction between the first direction and the second direction. This allows the burrs generated in the second direction and the inclined direction between the first direction and the second direction to directly contact the solid electrolyte layer 3 without directly contacting the positive electrode 1 or the negative electrode 2. In this way, the burrs on the positive electrode 1 and the burrs on the negative electrode 2 can be completely prevented from overlapping in the second direction and the inclined direction between the first direction and the second direction, thus better preventing short circuit problems caused by the burrs on the positive electrode 1 and the burrs on the negative electrode 2 overlapping. The second direction is perpendicular to the first direction, and the first direction is specifically as follows: Figure 1 As shown by arrow A in the diagram, the second direction is specifically as follows: Figure 1 As shown by arrow B in the diagram, that is, the first direction is specifically as follows: Figure 1 The horizontal direction in the text, the first direction is parallel to the direction of the length mentioned above, and the second direction is as follows: Figure 1 The vertical direction is the first direction, and the second direction is parallel to the thickness direction of the solid-state battery.

[0046] Furthermore, such as Figures 1 to 3 As shown, a first region 113 and a second region 114 are formed on at least one side of the positive electrode current collector 11, and the second region 114 is disposed around the first region 113; a first active material layer 12 is disposed on the first region 113, and a first adhesive layer 13 is disposed on the second region 114, and the inner edge of the first adhesive layer 13 is connected to the first active material layer 12.

[0047] By providing a first adhesive layer 13 on the second region 114 of the positive electrode current collector 11, and connecting the inner edge of the first adhesive layer 13 to the first active material layer 12, that is, by making the first adhesive layer 13 horizontally cover the outer peripheral die-cut edge of the first active material layer 12, the burrs at the outer peripheral die-cut edge of the first active material layer 12 can be covered into the first adhesive layer 13. This allows the burrs generated in the first direction to directly contact the first adhesive layer 13 without directly contacting the positive electrode 1 or the negative electrode 2. In the first direction, this avoids the burrs on the positive electrode 1 and the burrs on the negative electrode 2 from overlapping, further preventing short circuits caused by the burrs on the positive electrode 1 and the burrs on the negative electrode 2 overlapping. The thickness of the first adhesive layer 13 is equal to the thickness of the first active material layer 12, so as to better ensure that the solid electrolyte layer 3 completely covers the first active material layer 12, thereby completely isolating the positive electrode 1 and the negative electrode 2 through the solid electrolyte layer 3.

[0048] Furthermore, such as Figure 3 As shown, the positive electrode current collector 11 includes a first insulating base film 111 and a first conductive layer 112. The first insulating base film 111 has first conductive layers 112 disposed on opposite sides in a second direction to form a positive electrode composite current collector. Furthermore, the first conductive layer 112 is disposed on the first insulating base film 111 to form the aforementioned first region 113, so that the first active material layer 12 is disposed on the first conductive layer 112. The positive electrode composite current collector of the corresponding dimensions can be processed using existing magnetron sputtering technology or magnetron sputtering + electroplating technology. In other embodiments, the positive electrode current collector 11 can be a pure aluminum foil current collector, and the first conductive layer 112 can specifically be an aluminum deposition layer.

[0049] Specifically, such as Figure 3 As shown, the first insulating base film 111 includes a first support portion 1111 and a second support portion 1112. The first support portion 1111 is used to dispose of a first conductive layer 112. The second support portion 1112 is disposed around the first support portion 1111, and the second support portion 1112 has the aforementioned second region 114 formed thereon, so that the first adhesive layer 13 is disposed on the second support portion 1112. The first support portion 1111 and the second support portion 1112 are integrally formed.

[0050] like Figure 1 As shown, by providing a second support portion 1112, the first adhesive layer 13 can be supported, facilitating its installation and ensuring its stability on the first insulating base film 111. Specifically, the first insulating base film 111 can be a polyethylene terephthalate (PET) film or a polypropylene (PP) film, and the first adhesive layer 13 can be made of titanium alloy (AT9) or boehmite.

[0051] Specifically, the thickness of the second support portion 1112 is equal to the sum of the thickness of the first conductive layer 112 and the thickness of the first support portion 1111, so that the second support portion 1112 has better support strength and can better ensure that the solid electrolyte layer 3 completely covers the first active material layer 12.

[0052] Furthermore, such as Figure 1 As shown, the negative electrode 2 has a structure that is basically the same as the positive electrode 1 described above; a third region and a fourth region are formed on at least one side of the negative electrode current collector, and the fourth region is arranged around the third region; a second active material layer 22 is disposed on the third region, such that the solid electrolyte layer 3 is located between the first active material layer 12 and the second active material layer 22; and a second adhesive layer 23 is disposed on the fourth region, and the inner edge of the second adhesive layer 23 is connected to the second active material layer 22.

[0053] By providing a second adhesive layer 23 on the fourth region of the negative electrode current collector, and connecting the inner edge of the second adhesive layer 23 to the second active material layer 22, that is, by making the second adhesive layer 23 horizontally cover the outer peripheral die-cut edge of the second active material layer 22, the burrs at the outer peripheral die-cut edge of the second active material layer 22 can be covered into the first adhesive layer 13. This allows the burrs generated in the first direction to directly contact the first adhesive layer 13 without directly contacting the positive electrode 1 or the negative electrode 2. In this way, in the first direction, the burrs on the positive electrode 1 and the burrs on the negative electrode 2 can be prevented from overlapping each other, further preventing short circuit problems caused by the burrs on the positive electrode 1 and the burrs on the negative electrode 2 overlapping. The thickness of the second adhesive layer 23 is equal to the thickness of the second active material layer 22, so as to better ensure that the solid electrolyte layer 3 completely covers the second active material layer 12.

[0054] like Figure 1 As shown, in this embodiment, in the first direction, the two ends of the solid electrolyte layer 3 are flush with the two ends of the second adhesive layer 23. That is, in the first direction, the length of the solid electrolyte layer 3 is equal to the sum of the length of the second active material layer 22 and the length of the second adhesive layer 23. This ensures that the solid electrolyte layer 3 completely covers the second active material layer 22, and also makes the solid battery more aesthetically pleasing and facilitates subsequent processing and assembly.

[0055] That is to say, such as Figure 1 As shown, in this embodiment, the solid electrolyte layer 3 is located between the first active material layer 12 / first adhesive layer 13 and the second active material layer 22 / second adhesive layer 23; and in the first direction, the opposite ends of the solid electrolyte layer 3 are simultaneously aligned with the opposite ends of the first adhesive layer 13 and the opposite ends of the second adhesive layer 23.

[0056] It is worth noting that, in order to facilitate processing and ensure the aesthetic appearance of the solid-state battery, the first active material layer 12 and the second active material layer 22 are made to have the same shape and size, the first adhesive layer 13 and the second adhesive layer 23 are made to have the same shape and size, and the solid electrolyte layer 3 is made to have the same shape as the entire positive electrode 1 and the entire negative electrode 2, respectively.

[0057] Furthermore, such as Figure 1 As shown, the negative electrode current collector includes a second insulating base film 211 and a second conductive layer 212. The second insulating base film 211 has second conductive layers 212 disposed on opposite sides in a second direction to form a negative electrode composite current collector. Furthermore, the second conductive layers 212 are disposed on the second conductive layer 212 to form the aforementioned third region, so that the second active material layer 22 is disposed on the second conductive layer 212. The negative electrode composite current collector of the corresponding dimensions can be processed using existing magnetron sputtering technology or magnetron sputtering + electroplating technology. Specifically, the second conductive layer 212 can be a copper deposition layer.

[0058] Specifically, similar to the first insulating base film 111 described above, the second insulating base film 211 includes a third support portion and a fourth support portion. A second conductive layer 212 is disposed on the third support portion, and the fourth support portion is disposed around the third support portion, with the aforementioned fourth region formed on the fourth support portion, so that the second adhesive layer 23 is disposed on the fourth support portion. The third and fourth support portions are integrally formed.

[0059] By providing a fourth support portion, the second adhesive layer 23 can be supported, facilitating its installation and ensuring its stability on the second insulating base film 211. Specifically, the second insulating base film 211 can be a polyethylene terephthalate (PET) film or a polypropylene (PP) film, and the second adhesive layer 23 can be made of titanium alloy (AT9) or boehmite.

[0060] In this embodiment of the solid-state battery, the length of the negative electrode 2 is greater than or equal to the length of the positive electrode 1, the width of the negative electrode 2 is greater than or equal to the width of the positive electrode 1, and the length of the solid electrolyte layer 3 is equal to the length of the negative electrode 2, and the width of the solid electrolyte layer 3 is equal to the width of the negative electrode 2. This allows the solid electrolyte layer 3 to completely cover the positive electrode 1, thereby completely isolating the positive electrode 1 and the negative electrode 2. This better solves the short circuit problem caused by the overlap of burrs on the positive electrode 1 and the negative electrode 2.

[0061] In this embodiment, the solid-state battery, by providing a solid electrolyte layer 3, prevents the burrs on the positive electrode 1 from overlapping with the burrs on the negative electrode 2 in the second direction and the inclined direction between the first and second directions. Furthermore, by providing a first adhesive layer 13 and a second adhesive layer 23, it prevents the burrs on the positive electrode 1 from overlapping with the burrs on the negative electrode 2 in the first direction. That is, by providing the mutually cooperating solid electrolyte layer 3, the first adhesive layer 13, and the second adhesive layer 23, the first adhesive layer 13 and the second adhesive layer 23 can block the extension and overlap of burrs in the first direction, and simultaneously, the solid electrolyte layer 3 can block the extension and overlap of burrs in the second direction and the inclined direction between the first and second directions. This avoids a decrease in insulation between the positive electrode 1 and the negative electrode 2 and the risk of short circuits, completely isolating the positive electrode 1 and the negative electrode 2, effectively preventing short circuits caused by the overlap of burrs on the positive electrode 1 and the negative electrode 2, and better improving the safety performance and service life of the solid-state battery.

[0062] Example 2

[0063] This embodiment proposes a solid-state battery, which has a structure that is basically the same as that of the solid-state battery in Embodiment 1. The difference is that the structure of the negative electrode 2 in this embodiment is different from that of the negative electrode 2 in Embodiment 1.

[0064] Specifically, such as Figure 4 As shown, the negative electrode 2 includes a copper foil current collector 41 and a third active material layer 42; that is, the current collector of the negative electrode 2 in this embodiment is a pure metal current collector and no composite current collector is formed; the copper foil current collector 41 is provided with a third active material layer 42 on both sides in the second direction, and the solid electrolyte layer 3 is located between the third active material layer 42 and the first active material layer 12 / first adhesive layer 13.

[0065] It is worth noting that, such as Figure 4 As shown, in this embodiment, the second adhesive layer 23 is not provided in the negative electrode 2. However, due to the barrier effect of the first adhesive layer 13 and the solid electrolyte layer 3, the isolation effect between the first active material layer 12 and the third active material layer 42 can be well guaranteed. Therefore, even without the second adhesive layer 23, the short circuit problem caused by the burrs on the positive electrode 1 overlapping with the burrs on the negative electrode 2 can be avoided, thereby better ensuring the safety and service life of the solid-state battery.

[0066] The above description is only a preferred embodiment of this utility model. For those skilled in the art, there will be changes in the specific implementation method and application scope based on the idea of ​​this utility model. The content of this specification should not be construed as a limitation of this utility model.

Claims

1. A solid-state battery, characterized in that, include: A positive electrode sheet (1) includes a positive current collector (11) and a first active material layer (12), wherein the first active material layer (12) is disposed on the positive current collector (11); The negative electrode (2) includes a negative current collector and a second active material layer (22), the second active material layer (22) being disposed on the negative current collector; the length of the negative electrode (2) is greater than or equal to the length of the positive electrode (1), and the width of the negative electrode (2) is greater than or equal to the width of the positive electrode (1); A solid electrolyte layer (3) is disposed between the positive electrode (1) and the negative electrode (2). The length of the solid electrolyte layer (3) is equal to the length of the negative electrode (2), and the width of the solid electrolyte layer (3) is equal to the width of the negative electrode (2).

2. The solid-state battery as described in claim 1, characterized in that, A first region (113) and a second region (114) are formed on at least one side of the positive current collector (11). The second region (114) is disposed around the first region (113). The first active material layer (12) is disposed on the first region (113). A first adhesive layer (13) is disposed on the second region (114), and the inner edge of the first adhesive layer (13) is connected to the first active material layer (12).

3. The solid-state battery as described in claim 2, characterized in that, The thickness of the first adhesive layer (13) is equal to the thickness of the first active material layer (12).

4. The solid-state battery as described in claim 2, characterized in that, The positive current collector (11) includes: First insulating base film (111); A first conductive layer (112) is disposed on the first insulating base film (111) to form the first region (113).

5. The solid-state battery as described in claim 4, characterized in that, The first insulating base film (111) includes a first support portion (1111) and a second support portion (1112). The first support portion (1111) is provided with the first conductive layer (112), the second support portion (1112) is disposed around the first support portion (1111), and the second support portion (1112) is formed with the second region (114).

6. The solid-state battery as described in claim 5, characterized in that, The thickness of the second support portion (1112) is equal to the sum of the thickness of the first conductive layer (112) and the thickness of the first support portion (1111).

7. The solid-state battery according to any one of claims 1-6, characterized in that, A third region and a fourth region are formed on at least one side of the negative electrode current collector. The fourth region is disposed around the third region. The second active material layer (22) is disposed on the third region. A second adhesive layer (23) is disposed on the fourth region, and the inner edge of the second adhesive layer (23) is connected to the second active material layer (22).

8. The solid-state battery as described in claim 7, characterized in that, The thickness of the second adhesive layer (23) is equal to the thickness of the second active material layer (22).

9. The solid-state battery as described in claim 7, characterized in that, The negative electrode current collector includes: Second insulating base film (211); A second conductive layer (212) is disposed on the second insulating base film (211) to form the third region.

10. The solid-state battery as described in claim 9, characterized in that, The second insulating base film (211) includes a third support portion and a fourth support portion. The third support portion is provided with the second conductive layer (212). The fourth support portion is disposed around the third support portion and the fourth region is formed on the fourth support portion.

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