A structure of an all-solid-state lithium battery

Abstract

The utility model discloses a kind of full-solid-state lithium battery structures, the full-solid-state lithium battery structure includes electrolyte layer and the negative pole sheet and positive pole sheet of being sequentially alternately arranged, negative pole sheet includes negative pole current collector and the negative pole active material layer of being arranged in the both sides of negative pole current collector, positive pole sheet includes positive pole current collector and the positive pole active material layer of being arranged in the both sides of positive pole current collector, electrolyte layer is arranged in the outermost side of full-solid-state lithium battery structure and is arranged between positive pole, negative pole active material layer;Positive pole active material layer and negative pole active material layer are all set to equal size. The side of positive pole current collector and negative pole current collector is die-cut with positive pole lug and negative pole lug, first insulating substance layer is arranged on the lug side of full-solid-state lithium battery structure, second insulating substance layer is coated on the remaining side surface except lug side. The utility model greatly improves the production efficiency of full-solid-state lithium battery structure, simple structure;Abandon insulating rubber frame, can reduce raw material and production cost in production process.

Description

Technical Field

[0001] This utility model belongs to the field of solid-state battery technology, specifically relating to an all-solid-state lithium battery structure. Background Technology

[0002] Solid-state lithium batteries use solid electrolytes instead of traditional liquid electrolytes, fundamentally solving the risk of thermal runaway. Theoretically, their energy density can reach over 500 Wh / kg, and they support operation in a wide temperature range of -40 to 120°C, making them a core direction for next-generation battery technology. However, the "negative electrode surrounding positive electrode" structure of traditional liquid lithium batteries (negative electrode area > positive electrode) relies on the flexible buffering of the separator. In solid-state lithium batteries, the electrolyte layer needs to be directly stacked with the electrode layer. Traditional lithium battery structures are prone to uneven interface stress distribution and electrolyte layer fracture during subsequent isostatic pressing or flat plate pressing processes, leading to internal short circuits within the battery.

[0003] Currently, the mainstream all-solid-state lithium battery structure used by various companies involves adding an insulating frame around the positive electrode to reduce the shear stress on the electrolyte layer inside the battery during isostatic pressing or planar pressing processes. However, this operation has drawbacks such as cumbersome processes, low production efficiency, and high equipment precision requirements, making it unsuitable for large-scale industrial production. Therefore, a novel all-solid-state lithium battery structure is needed to replace the insulating frame and solve the aforementioned problems in the actual production of all-solid-state lithium batteries. Utility Model Content

[0004] To address the issues of low production efficiency and inability to mass-produce mainstream all-solid-state lithium battery structures, this invention proposes an all-solid-state lithium battery structure that can greatly improve battery production efficiency and enable industrial production. At the same time, it can solve the short-circuit problem caused by uneven interface stress distribution in the electrostatic pressing or flat plate pressing process of traditional solid-state battery production.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: An all-solid-state lithium battery structure includes an electrolyte layer and negative electrode sheets and positive electrode sheets arranged alternately in sequence. The negative electrode sheet includes a negative current collector and negative active material layers disposed on both sides of the negative current collector. The positive electrode sheet includes a positive current collector and positive active material layers disposed on both sides of the positive current collector. The electrolyte layer is disposed on the outermost side of the all-solid-state lithium battery structure and between the positive active material layers and the negative active material layers. The positive current collector has a positive electrode tab die-cut in one dimension, and the negative current collector has a corresponding negative electrode tab die-cut in the same direction as the positive electrode tab. The all-solid-state lithium battery structure has a first insulating material layer on the side of the negative electrode active material layer and the corresponding electrolyte layer on the negative electrode tab side, and a first insulating material layer on the side of the positive electrode active material layer on the positive electrode tab side; and a second insulating material layer on the remaining sides excluding the positive electrode tab and negative electrode tab sides.

[0006] Furthermore, the positive electrode active material layer, the negative electrode active material layer, and the electrolyte layer are all of equal size.

[0007] Furthermore, the positive electrode current collector portion, except for the positive electrode tab, is set to the same size as the positive electrode active material layer.

[0008] Furthermore, the remaining negative electrode current collector portion, except for the negative electrode tab, is set to the same size as the negative electrode active material layer.

[0009] Furthermore, the positive electrode tab of the positive current collector and the negative electrode tab of the adjacent negative current collectors in the upper and lower layers are offset on the same side.

[0010] Preferably, the first insulating material layer is an insulating material that does not have electronic conduction function; the second insulating material layer is an insulating material that does not have lithium ion conduction function.

[0011] Preferably, the first insulating layer is composed of one of PVDF, UV adhesive, and ceramic; the second insulating layer is composed of one of PVDF, UV adhesive, PP, and PE.

[0012] Compared with the prior art, the technical solution of this utility model has the following beneficial effects: This invention significantly improves the production efficiency of all-solid-state lithium batteries, enabling roll-to-roll production with a simple structure. By eliminating the need for an insulating frame, it reduces raw material and production costs. Simultaneously, it ensures complete adhesion between the insulating layer and the positive and negative electrode active materials without gaps. This effectively avoids the problem of gaps between the insulating frame and the active materials caused by assembly precision issues when using pre-cut insulating frames, which can lead to electrolyte embedding and breakage during isostatic pressing. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the positive electrode die-cutting roll structure of this utility model; Figure 2 This is a schematic diagram of the negative electrode die-cutting roll structure of this utility model; Figure 3 This is a schematic diagram of the positive and negative electrode structures of this utility model; Figure 4 This is a schematic diagram of the all-solid-state lithium battery structure of this utility model; Figure 5This is a schematic diagram of the insulation treatment related to the all-solid-state lithium battery structure of this utility model; Figure 6 Schematic diagram of the all-solid-state lithium battery structure of this utility model - 1; In the diagram: 1. Positive electrode plate; 11. Positive current collector; 12. Positive active material layer; 13. Positive electrode tab; 2. Negative electrode plate; 21. Negative current collector; 22. Negative active material layer; 23. Negative electrode tab; 3. Electrolyte layer; 4. First insulating material layer; 5. Second insulating material layer. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0015] refer to Figures 1-4 This embodiment of an all-solid-state lithium battery structure includes an electrolyte layer 3 and a negative electrode 2 and a positive electrode 1 arranged alternately in sequence. The negative electrode 2 includes a negative current collector 21 and negative active material layers 22 disposed on both sides of the negative current collector 21. The positive electrode 1 includes a positive current collector 11 and positive active material layers 12 disposed on both sides of the positive current collector 11. The electrolyte layer 3 is disposed on the outermost side of the all-solid-state lithium battery structure and between the positive active material layer 12 and the negative active material layer 22. The positive active material layer 12, the negative active material layer 22, and the electrolyte layer are all of equal size.

[0016] Positive electrode tab 13 and negative electrode tab 23 are die-cut on one side of the positive electrode current collector 11 and the negative electrode current collector 21, respectively. A first insulating material layer 4 is disposed on the tab side of the all-solid-state lithium battery structure. The material of the first insulating material layer 4 can be selected from insulating materials that do not have electronic conduction function, such as PVDF, UV adhesive, and ceramics. Among them, PVDF and UV adhesive can be coated by brushing, and ceramics are coated by using a nozzle to achieve ceramic slurry coating.

[0017] The all-solid-state lithium battery structure has a second insulating material layer 5 coated on the remaining sides except for the positive electrode tab 13 and the negative electrode tab 23. Figure 5 As shown. The second insulating layer 5 can be made of insulating materials that do not have lithium-ion conductivity, such as PVDF, UV adhesive, PP, or PE, and is applied by brushing adhesive.

[0018] The positive electrode active material in this invention can be LiMPO4 or LiNO2, wherein M can be at least one of Fe, Co, Ni, or Mn, and N can be at least one of Ni, Co, Mn, or Al. As an example, the positive electrode active material can be lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), lithium manganese oxide (LMO), lithium cobalt oxide (LCO), lithium nickel manganese oxide (LNMO), lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), etc.; the negative electrode active material can be at least one of carbon materials, silicon-based materials, metal oxide materials, metallic lithium, and lithium alloys; the electrolyte material can be at least one of sulfide solid electrolytes, halide solid electrolytes, oxide solid electrolytes, and polymer solid electrolytes.

[0019] This embodiment describes a method for fabricating an all-solid-state lithium battery structure, including the following process steps: S11: The negative electrode roll and the electrolyte roll are transferred and laminated together or the electrolyte is directly coated onto the surface of the negative electrode roll to obtain the negative electrode-electrolyte roll. S12: Perform pre-die-cutting on the coated positive electrode roll and the negative electrode-electrolyte roll obtained in step S11. Pre-cut the corresponding positive electrode tabs 13 and negative electrode tabs 23 on the positive electrode current collector 11 and negative electrode current collector 21. After pre-die-cutting, coat the tab sides of the positive electrode roll and the negative electrode-electrolyte roll with a first insulating material layer 4 for insulation treatment. The thickness of the insulating material layer is equivalent to the thickness of the effective materials of the positive and negative electrodes, resulting in positive electrode rolls and negative electrode rolls to be die-cut. The structure of the positive electrode roll to be die-cut is as follows: Figure 1 The structure shown includes a positive electrode active material layer 12, a positive electrode current collector 11 (not shown in the figure), a positive electrode tab 13, and a first insulating material layer 4; the structure of the negative electrode roll to be die-cut is as follows. Figure 2 The diagram shows a negative electrode active material layer 22 (at this time, the negative electrode active material layer 22 and the electrolyte layer 3 are closely attached), a negative electrode current collector 21 (not shown in the figure), a negative electrode tab 23, and a first insulating material layer 4. S13: Die-cut the positive electrode roll and the negative electrode roll to obtain the positive electrode sheet 1 (e.g. Figure 3 (as shown in Figure a) and negative electrode plate 2 (as shown in Figure a) Figure 3 As shown in Figure b), several positive electrode plates 1 and negative electrode plates 2 are alternately stacked to obtain a stacked body, provided that the positive electrode tabs 13 and negative electrode tabs 23 are staggered. S14: After isostatic pressing or flat pressing of the laminate, a second insulating material layer 5 is coated on the remaining sides except for the positive electrode tab 13 and the negative electrode tab 23, such as... Figure 5 As shown; S15: The resulting stacked body undergoes subsequent welding and encapsulation operations to obtain the all-solid-state lithium battery structure, such as... Figure 4 As shown; The preparation process of the positive electrode roll and the negative electrode roll is as follows: the corresponding positive electrode active material or negative electrode active material is coated on both sides of the positive electrode current collector by a coating process, or a film is formed by a dry electrode process and combined with the current collector to form a roll. Among them, the dry electrode process film formation is to directly form a film by dry mixing of materials, fiberization, and then roll pressing, without the involvement of solvents.

[0020] It should be noted that the all-solid-state lithium battery structure of this invention can be modified by changing the relative positions of the positive and negative electrode plates to obtain a similar all-solid-state lithium battery structure, such as... Figure 6 As shown.

[0021] In summary, this invention prevents short circuits between the foils on the tab side by adding an insulating layer, while also providing support and reducing the risk of tab breakage due to external pressure in subsequent processes. Compared to the commonly used frame-type materials, this invention can be directly integrated into industrial production, enabling roll-to-roll operations and perfectly avoiding the gap problems caused by intermittent production and manufacturing tolerances associated with frames. It upgrades experimental manufacturing methods to mass production capabilities. Furthermore, to mitigate the risk of short circuits at the edges of electrodes of equal size, this invention also applies an insulating layer to the cell cross-section. Due to the electrolyte-free nature of all-solid-state cells, this insulating layer effectively prevents short circuits between the positive and negative electrodes.

[0022] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A solid-state lithium battery structure, characterized in that, The structure includes an electrolyte layer (3) and alternating negative electrode plates (2) and positive electrode plates (1). The negative electrode plate (2) includes a negative current collector (21) and negative active material layers (22) disposed on both sides of the negative current collector (21). The positive electrode plate (1) includes a positive current collector (11) and positive active material layers (12) disposed on both sides of the positive current collector (11). The electrolyte layer (3) is disposed on the outermost side of the all-solid-state lithium battery structure and between the positive active material layer (12) and the negative active material layer (22). The positive current collector (11) has a positive electrode tab (13) die-cut in one dimension direction, and the negative current collector (21) has a corresponding negative electrode tab (23) die-cut in the same direction as the positive electrode tab (13). The all-solid-state lithium battery structure has a first insulating material layer (4) on the side of the negative electrode active material layer (22) and the corresponding electrolyte layer (3) on the side of the negative electrode tab (23), and a first insulating material layer (4) on the side of the positive electrode active material layer (12) on the side of the positive electrode tab (13); and a second insulating material layer (5) on the other sides except for the positive electrode tab (13) and the negative electrode tab (23).

2. The all-solid-state lithium battery structure according to claim 1, characterized in that, The positive electrode active material layer (12), the negative electrode active material layer (22), and the electrolyte layer (3) are all of equal size.

3. The all-solid-state lithium battery structure according to claim 2, characterized in that, Except for the positive electrode tab (13), the remaining positive electrode current collector (11) is set to the same size as the positive electrode active material layer (12).

4. The all-solid-state lithium battery structure according to claim 2, characterized in that, Except for the negative electrode tab (23), the remaining negative electrode current collector (21) and the negative electrode active material layer (22) are set to the same size.

5. The all-solid-state lithium battery structure according to claim 2, characterized in that, The positive electrode tab (13) of the positive current collector (11) and the negative electrode tab (23) of the adjacent negative current collector (21) are offset on the same side.

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