Electrode assembly and solid-state battery and electric device

Abstract

The utility model provides a kind of electrode assembly and solid-state battery and electric equipment, the electrode assembly includes: at least one positive pole piece, positive pole piece includes positive pole current collector and the positive pole active layer and first insulating layer being arranged in one side of positive pole current collector, first insulating layer is arranged in the edge circumferential of positive pole active layer;At least one negative pole piece, negative pole piece includes negative pole current collector and the negative pole active layer and second insulating layer being arranged in one side of negative pole current collector, second insulating layer is arranged in the edge circumferential of negative pole active layer, and the second insulating layer end away from negative pole current collector and first insulating layer are abutted;At least one electrolyte layer, electrolyte layer is arranged between positive pole active layer and negative pole active layer;Wherein, positive pole piece, negative pole piece and electrolyte layer are stacked along first direction arrangement.The utility model can play the role of supporting positive pole current collector and negative pole current collector by setting first insulating layer and second insulating layer, reduce electrode assembly failure risk.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to an electrode assembly, a solid-state battery, and an electrical device. Background Technology

[0002] With the increasing popularity of electric vehicles, the demand for highly safe rechargeable batteries is growing, which is prompting the accelerated commercialization of all-solid-state batteries with better thermal safety and lower explosion risk.

[0003] The manufacturing process of all-solid-state batteries mainly relies on high-pressure pressing to improve solid-solid interface contact. The stress generated during pressurization will preferentially accumulate at the edges of the positive and negative electrode active layers. These accumulated stresses will act on the edges of the active layer and electrolyte layer from both sides simultaneously, making them extremely prone to breakage due to stress concentration, thus creating a short circuit hazard. Utility Model Content

[0004] The embodiments of this utility model provide an electrode assembly, a solid-state battery, and an electrical device, which can improve the technical problem of the fragile active layer and electrolyte layer at the edge of the battery.

[0005] In a first aspect, embodiments of the present invention provide an electrode assembly, comprising: At least one positive electrode, the positive electrode comprising a positive current collector and a positive active layer and a first insulating layer disposed on one side of the positive current collector, the first insulating layer being disposed on the circumferential edge of the positive active layer; At least one negative electrode sheet, the negative electrode sheet includes a negative electrode current collector and a negative electrode active layer and a second insulating layer disposed on one side of the negative electrode current collector, the second insulating layer is disposed on the circumferential edge of the negative electrode active layer, and the end of the second insulating layer away from the negative electrode current collector abuts against the first insulating layer; At least one electrolyte layer is disposed between the positive electrode active layer and the negative electrode active layer; The positive electrode, the negative electrode, and the electrolyte layer are stacked along a first direction.

[0006] In embodiments of this invention, by providing a first insulating layer and a second insulating layer between the positive electrode current collector and the negative electrode current collector, and by having the end of the second insulating layer facing away from the negative electrode current collector abut against the first insulating layer, the positive electrode active layer, the negative electrode active layer, and the electrolyte layer can be supported when under pressure. This disperses the stress in the positive electrode active layer, the negative electrode active layer, and the electrolyte layer, reduces the probability of breakage at the edges of the positive electrode active layer, the negative electrode active layer, and the electrolyte layer due to stress concentration, and thus reduces the risk of electrode assembly failure.

[0007] In one embodiment, the minimum width of the first insulating layer extending outward from the circumferential edge of the positive current collector in a direction away from the positive active layer is 0.1 mm to 0.5 mm.

[0008] In embodiments of this invention, by extending the first insulating layer beyond the circumferential edge of the positive current collector in a direction opposite to the positive active layer, burrs at the edges of the positive and negative current collectors can be isolated, reducing the probability of overlap of burrs at the edges of the positive and negative current collectors, thereby reducing the probability of short circuits caused by this. By controlling the minimum width of the first insulating layer extending beyond the circumferential edge of the positive current collector in a direction opposite to the positive active layer, it can be ensured that the first insulating layer effectively covers the areas where burrs exist at the edges of the positive and negative current collectors, fully isolating the burrs at the edges of the positive and negative current collectors, and simultaneously reducing the impact on the energy density of the solid-state battery.

[0009] In one embodiment, the minimum width of the second insulating layer extending outward from the circumferential edge of the negative electrode current collector in a direction opposite to the negative electrode active layer is 0.1 mm to 0.5 mm.

[0010] In embodiments of this invention, by extending the second insulating layer beyond the circumferential edge of the positive current collector in a direction away from the negative electrode active layer, burrs present at the edges of the positive and negative current collectors can be isolated, reducing the probability of overlap of burrs at the edges of the positive and negative current collectors, thereby reducing the probability of short circuits caused by this. By controlling the width of the second insulating layer extending beyond the circumferential edge of the positive current collector in a direction away from the negative electrode active layer, it can be ensured that the second insulating layer effectively covers the areas where burrs are present at the edges of the positive and negative current collectors, fully isolating the burrs at the edges of the positive and negative current collectors, and simultaneously reducing the impact on the energy density of the solid-state battery.

[0011] In one embodiment, a first groove is provided on the positive current collector along the first direction, and one end of the first insulating layer is embedded in the first groove.

[0012] In an embodiment of this utility model, by providing a first groove along a first direction on the positive current collector and embedding one end of the first insulating layer in the first groove, the first insulating layer and the positive current collector can be mechanically interlocked through the first groove, thereby reducing the probability of displacement of the first insulating layer during the pressure application to the electrode assembly.

[0013] In one embodiment, a second groove is provided on the negative electrode current collector along the first direction, and one end of the second insulating layer is embedded in the second groove.

[0014] In an embodiment of this utility model, by providing a second groove along the first direction on the negative electrode current collector and embedding one end of the second insulating layer in the second groove, the second insulating layer and the negative electrode current collector can be mechanically interlocked through the second groove, thereby reducing the probability of displacement of the second insulating layer during the pressure application to the electrode assembly.

[0015] In one embodiment, the depth of the first groove in the first direction is H1, and the thickness of the positive current collector in the first direction is H2, where 20% ≤ H1 / H2 ≤ 40%.

[0016] In embodiments of this utility model, by controlling the relationship between the depth of the first groove in the first direction and the thickness of the positive current collector in the first direction, the overall strength of the positive current collector can be guaranteed while ensuring the anchoring effect between the first insulating layer and the first groove, thereby reducing the probability of the positive current collector breaking.

[0017] In one embodiment, the width of the first groove along the direction of the first insulating layer away from the positive electrode active layer is H3, and the width of the first insulating layer along the direction away from the positive electrode active layer is H4, where 10% ≤ H3 / H4 ≤ 50%.

[0018] In embodiments of this invention, by controlling the relationship between the width of the first groove along the direction of the first insulating layer away from the positive electrode active layer and the width of the first insulating layer along the direction of the first insulating layer away from the positive electrode active layer, the overall strength of the positive electrode current collector can be guaranteed while ensuring the anchoring effect between the first insulating layer and the first groove, thereby reducing the probability of the positive electrode current collector breaking.

[0019] In one embodiment, the depth of the second groove in the first direction is H5, and the thickness of the negative electrode current collector in the first direction is H6, where 20% ≤ H5 / H6 ≤ 40%.

[0020] In embodiments of this utility model, by controlling the relationship between the depth of the second groove in the first direction and the thickness of the negative electrode current collector in the first direction, the overall strength of the negative electrode current collector can be guaranteed while ensuring the anchoring effect between the second insulating layer and the second groove, thereby reducing the probability of the negative electrode current collector breaking.

[0021] In one embodiment, the width of the second groove along the direction of the second insulating layer away from the negative electrode active layer is H7, and the width of the second insulating layer along the direction away from the negative electrode active layer is H8, where 10%≤H7 / H8≤50%.

[0022] In the embodiments of this utility model, by controlling the relationship between the width of the second groove along the direction of the second insulating layer away from the negative electrode active layer and the width of the second insulating layer along the direction of the negative electrode active layer, the overall strength of the negative electrode current collector can be guaranteed while ensuring the anchoring effect between the second insulating layer and the second groove, thereby reducing the probability of the negative electrode current collector breaking.

[0023] In one embodiment, the first insulating layer and the positive electrode active layer are spaced apart.

[0024] In embodiments of this invention, by spacing the first insulating layer from the positive electrode active layer, it can accommodate the lateral deformation of the first insulating layer under high pressure, reducing the probability of its lateral deformation compressing the positive electrode active layer and the electrolyte layer, thereby reducing the probability of the edge material of the positive electrode active layer and the electrolyte layer breaking.

[0025] In one embodiment, the second insulating layer is spaced apart from the negative electrode active layer.

[0026] In embodiments of this invention, by spacing the second insulating layer from the negative electrode active layer, it can accommodate the lateral deformation of the second insulating layer under high pressure, reducing the probability of its lateral deformation compressing the negative electrode active layer and the electrolyte layer, thereby reducing the probability of the edge material of the negative electrode active layer and the electrolyte layer breaking.

[0027] In one embodiment, the first insulating layer is spaced 30 μm-100 μm apart from the positive electrode active layer.

[0028] In the embodiments of this utility model, by controlling the spacing between the first insulating layer and the positive electrode active layer, the lateral deformation of the first insulating layer under high pressure can be fully accommodated, reducing the probability of its lateral deformation squeezing the positive electrode active layer and the electrolyte layer. At the same time, the impact on the energy density of the solid-state battery can be reduced.

[0029] In one embodiment, the second insulating layer is spaced 30 μm-100 μm from the negative electrode active layer.

[0030] In embodiments of this invention, by controlling the spacing between the second insulating layer and the negative electrode active layer, the lateral deformation of the second insulating layer under high pressure can be fully accommodated, reducing the probability of its lateral deformation squeezing the negative electrode active layer and the electrolyte layer. At the same time, the impact on the energy density of the solid-state battery can be reduced.

[0031] In one embodiment, please refer to Figure 1 The shortest distance between the circumferential edge of the positive electrode active layer and the circumferential edge of the positive electrode current collector is H9, where H9 > 0.8 mm, and the area of ​​the positive electrode active layer is greater than or equal to 80% of the area of ​​the positive electrode current collector.

[0032] In the embodiments of this utility model, by controlling the shortest distance between the circumferential edge of the positive electrode active layer and the circumferential edge of the positive electrode current collector, the first insulating layer disposed on the circumferential edge of the positive electrode current collector can have a sufficient width, thereby ensuring that it has a good insulation effect. At the same time, by controlling the area of ​​the positive electrode active layer to be greater than or equal to 80% of the area of ​​the positive electrode current collector, the solid-state battery can be guaranteed to have a high energy density.

[0033] In one embodiment, please refer to Figure 1 The shortest distance between the circumferential edge of the negative electrode active layer and the circumferential edge of the negative electrode current collector is H. 10 H 10 The diameter is greater than 0.8 mm, and the area of ​​the negative electrode active layer is greater than or equal to 80% of the area of ​​the negative electrode current collector.

[0034] In the embodiments of this utility model, by controlling the shortest distance between the circumferential edge of the negative electrode active layer and the circumferential edge of the negative electrode current collector, the second insulating layer disposed on the circumferential edge of the negative electrode current collector can have a sufficient width, thereby ensuring that it has a good insulation effect. At the same time, by controlling the area of ​​the negative electrode active layer to be greater than or equal to 80% of the area of ​​the negative electrode current collector, the solid-state battery can be guaranteed to have a high energy density.

[0035] In one embodiment, the minimum width by which the circumferential edge of the negative electrode active layer extends beyond the circumferential edge of the positive electrode active layer is 1 mm to 3 mm.

[0036] In embodiments of this invention, by making the minimum width of the circumferential edge of the negative electrode active layer exceeding the circumferential edge of the positive electrode active layer by 1mm to 3mm, the negative electrode active layer can completely cover the positive electrode active layer, leaving a margin to accommodate volume changes of the negative electrode active layer, and minimizing the margin within a safety threshold, thereby maximizing the energy density of the solid-state battery.

[0037] In one embodiment, the circumferential edge of the electrolyte layer is flush with the circumferential edge of the negative electrode active layer.

[0038] In embodiments of this invention, by aligning the circumferential edge of the electrolyte layer with the circumferential edge of the negative electrode active layer, the electrolyte layer can effectively separate the negative electrode active layer and the positive electrode active layer, while reducing the space occupied by the electrolyte layer and improving the energy density of the solid-state battery.

[0039] In one embodiment, the circumferential edge of the electrolyte layer extends beyond the circumferential edge of the positive electrode active layer and covers the periphery of the positive electrode active layer.

[0040] In embodiments of this invention, by extending the circumferential edge of the electrolyte layer beyond the circumferential edge of the positive electrode active layer and covering the periphery of the positive electrode active layer, the stress on the edge of the positive electrode active layer can be alleviated when the electrode assembly is under pressure. At the same time, during the later cycling process of the electrode assembly, the electrolyte layer on the periphery of the positive electrode active layer can also play a buffering role, reducing the probability of the positive electrode active layer cracking due to lateral expansion and compression of the second insulating layer.

[0041] In one embodiment, the circumferential edge of the electrolyte layer extends beyond the circumferential edge of the negative electrode active layer and covers the periphery of the negative electrode active layer.

[0042] In embodiments of this invention, by extending the circumferential edge of the electrolyte layer beyond the circumferential edge of the negative electrode active layer and covering the periphery of the negative electrode active layer, the stress on the edge of the negative electrode active layer can be alleviated when the electrode assembly is under pressure. At the same time, during the later cycling process of the electrode assembly, the electrolyte layer on the periphery of the negative electrode active layer can also play a buffering role, reducing the probability of the negative electrode active layer cracking due to lateral expansion and compression of the second insulating layer.

[0043] In one embodiment, the circumferential edge of the electrolyte layer extends beyond the minimum width of the circumferential edge of the positive electrode active layer by 10 μm to 30 μm.

[0044] In embodiments of this invention, by controlling the width of the circumferential edge of the electrolyte layer extending beyond the circumferential edge of the positive electrode active layer, the buffering effect of the electrolyte layer on the periphery of the positive electrode active layer can be ensured, while reducing the impact on the energy density of the solid-state battery.

[0045] In one embodiment, the circumferential edge of the electrolyte layer extends beyond the minimum width of the circumferential edge of the negative electrode active layer by 10 μm to 30 μm.

[0046] In embodiments of this invention, by controlling the width of the circumferential edge of the electrolyte layer beyond the circumferential edge of the negative electrode active layer, the buffering effect of the electrolyte layer on the periphery of the negative electrode active layer can be ensured, while reducing the impact on the energy density of the solid-state battery.

[0047] In one embodiment, the positive electrode includes a first positive electrode and a second positive electrode, the negative electrode includes a first negative electrode and a second negative electrode, and the electrolyte layer includes a first electrolyte layer and a second electrolyte layer. The first negative electrode, the first electrolyte layer, the first positive electrode, the second positive electrode, the second electrolyte layer, and the second negative electrode are stacked along a first direction.

[0048] Secondly, embodiments of the present invention provide a solid-state battery, including at least one of the above-described electrode components.

[0049] Thirdly, embodiments of the present invention provide an electrical device including the aforementioned electrode assembly and / or the aforementioned solid-state battery. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of an electrode assembly provided in an embodiment of the present invention; Figure 2 This is another structural schematic diagram of the electrode assembly provided in an embodiment of the present invention; Figure 3 This is another structural schematic diagram of the electrode assembly provided in an embodiment of the present utility model; Figure 4 This is another structural schematic diagram of the electrode assembly provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the positive electrode sheet provided in an embodiment of this utility model; Figure 6 This is a schematic diagram of the negative electrode sheet provided in an embodiment of this utility model.

[0052] Explanation of reference numerals in the attached drawings: Positive electrode sheet - 1; Positive current collector - 11; Positive active layer - 12; First insulating layer - 13; First groove - 14; Negative electrode sheet - 2; Negative current collector - 21; Negative active layer - 22; Second insulating layer - 23; Second groove - 24; Electrolyte layer - 3. Detailed Implementation

[0053] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0054] An embodiment of this utility model provides an electrical device, including an electrode assembly and / or a solid-state battery.

[0055] It is understandable that the electrical equipment can be electric vehicles, electric bicycles, and other electrical equipment that can use solid-state batteries.

[0056] The solid-state battery provided in the embodiments of this utility model includes at least one electrode assembly.

[0057] It is understood that a solid-state battery may include one or more electrode components, and multiple electrode components can be connected in parallel or in series.

[0058] Please see Figures 1-6 The electrode assembly provided in the embodiments of this utility model includes: At least one positive electrode 1, the positive electrode 1 includes a positive current collector 11 and a positive active layer 12 and a first insulating layer 13 disposed on one side of the positive current collector 11, the first insulating layer 13 being disposed on the circumferential edge of the positive active layer 12; At least one negative electrode 2, the negative electrode 2 includes a negative current collector 21 and a negative active layer 22 and a second insulating layer 23 disposed on one side of the negative current collector 21. The second insulating layer 23 is disposed on the circumferential edge of the negative active layer 22, and the end of the second insulating layer 23 away from the negative current collector 21 abuts against the first insulating layer 13. At least one electrolyte layer 3 is disposed between the positive electrode active layer 12 and the negative electrode active layer 22; The positive electrode 1, the negative electrode 2, and the electrolyte layer 3 are stacked along a first direction.

[0059] It is understood that the first insulating layer 13 and the second insulating layer 23 can separate the electrolyte layer 3 from the edges of the positive electrode current collector 11 and the negative electrode current collector 21, thereby reducing the probability of burrs present at the edges of the positive electrode current collector 11 and the negative electrode current collector 21 piercing the electrolyte layer 3, and thus reducing the probability of short-circuit failure caused by this. The first insulating layer 13 and the second insulating layer 23 can also achieve a high degree of adhesion between the positive electrode sheet 1 and the negative electrode sheet 2, reducing the probability of interface separation caused by volume expansion during solid-state battery operation. The abutting first insulating layer 13 and the second insulating layer 23 can maintain a tight adhesion between the positive electrode active layer 12 and the negative electrode active layer 22 and the electrolyte layer 3 during solid-state battery cycling, improving the interface contact failure problem during long-term operation of solid-state batteries.

[0060] As an example, the positive current collector 11 and the negative current collector 21 are the same size and shape and are positioned facing each other.

[0061] As an example, the first insulating layer 13 and the second insulating layer 23 can be formed of a ceramic composite elastomer material, which may consist of an elastic matrix material, a tackifier, a ceramic insulating filler, and a dynamic crosslinking agent. When the first insulating layer 13 and the second insulating layer 23 are formed, the thickness of the first insulating layer 13 and the thickness of the second insulating layer 23 after curing can be controlled so that the two can abut against each other after being compressed, thereby achieving good adhesion of the internal interface of the solid-state battery after isostatic pressing.

[0062] As an example, the positive electrode 1, the negative electrode 2, and the electrolyte layer 3 can be stacked by hot pressing.

[0063] As an example, the positive current collector 11 includes aluminum foil, nickel foil, titanium foil, stainless steel foil, carbon-coated foil, composite metal foil, and alloy foil, etc.

[0064] As an example, the negative electrode current collector 21 includes copper foil, nickel foil, titanium foil, stainless steel foil, carbon-coated foil, composite metal foil, and alloy foil, etc.

[0065] As an example, during fabrication, electrolyte layer 3 can be disposed on the surface of the positive electrode active layer (e.g., Figure 3 (As shown), it can also be disposed on the surface of the negative electrode active layer 22 (such as... Figure 2 and Figure 4 As shown), it can also be simultaneously disposed on the surface of the positive electrode active layer 22 and the surface of the negative electrode active layer 22 (as shown). Figure 1 (As shown). By placing the electrolyte layer 3 only on the surface of the positive electrode active layer or the surface of the negative electrode active layer 22, the volumetric energy density of the solid-state battery can be effectively improved while reducing the failure risk of individual cells.

[0066] In one embodiment, the minimum width of the first insulating layer 13 extending outward from the circumferential edge of the positive electrode current collector 11 in a direction away from the positive electrode active layer 12 is 0.1 mm to 0.5 mm, for example, it can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc.

[0067] It is understandable that the width of the first insulating layer 13 extending from the positive electrode active layer 12 to the circumferential edge of the positive electrode current collector 11 is too low, resulting in poor coverage of the areas with burrs at the edges of the positive electrode current collector 11 and the negative electrode current collector 21; the width of the first insulating layer 13 extending from the positive electrode active layer 12 to the circumferential edge of the positive electrode current collector 11 is too high, occupying a large space and reducing the energy density of the solid-state battery.

[0068] In one embodiment, the minimum width of the second insulating layer 23 extending outward from the circumferential edge of the negative electrode current collector 21 in a direction away from the negative electrode active layer 22 is 0.1mm to 0.5mm, for example, it can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, etc.

[0069] It is understandable that the minimum width of the second insulating layer 23 extending outward from the circumferential edge of the positive current collector 11 in the direction away from the negative electrode active layer 22 (i.e., the vertical distance between the circumferential edge of the positive current collector 11 and the circumferential edge of the second insulating layer 23 and the negative electrode active layer 22) is too small, resulting in poor coverage of the areas with burrs at the edges of the positive electrode current collector 11 and the negative electrode current collector 21; the minimum width of the second insulating layer 23 extending outward from the circumferential edge of the positive electrode current collector 11 in the direction away from the negative electrode active layer 22 is too large, occupying a large space and reducing the energy density of the solid-state battery.

[0070] In one embodiment, the positive current collector 11 is provided with a first groove 14 opened along the first direction, and one end of the first insulating layer 13 is embedded in the first groove 14.

[0071] It is understood that this application does not limit the shape of the first groove 14. As an example, the first groove 14 can be a strip groove, a conical groove, a trapezoidal groove, etc.

[0072] In one embodiment, the negative electrode current collector 21 is provided with a second groove 24 opened along the first direction, and one end of the second insulating layer 23 is embedded in the second groove 24.

[0073] It is understood that this application does not limit the shape of the second groove 24. As an example, the second groove 24 can be a strip groove, a conical groove, a trapezoidal groove, etc.

[0074] As an example, the first groove 14 and the second groove 24 are arranged opposite each other.

[0075] In one embodiment, please refer to Figure 1 The depth of the first groove 14 in the first direction is H1, and the thickness of the positive current collector 11 in the first direction is H2, 20%≤H1 / H2≤40%.

[0076] It is understandable that when H1 / H2 is less than 20%, the depth of the first groove 14 is small, and the anchoring effect between the first insulating layer 13 and the first groove 14 is not good; when H1 / H2 is greater than 40%, the depth of the first groove 14 is large, which greatly reduces the strength of the positive current collector 11 and easily leads to the current collector breaking. As an example, H1 / H2 can be 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, etc.

[0077] In one embodiment, please refer to Figure 1The width of the first groove 14 along the direction of the first insulating layer 13 away from the positive electrode active layer 12 is H3, and the width of the first insulating layer 13 along the direction away from the positive electrode active layer 12 is H4, 10%≤H3 / H4≤50%.

[0078] It is understandable that when H3 / H4 is less than 10%, the width of the first groove 14 is small, and the anchoring effect between the first insulating layer 13 and the first groove 14 is not good; when H3 / H4 is greater than 50%, the width of the first groove 14 is large, which greatly reduces the strength of the positive current collector 11 and easily leads to the current collector breaking. As an example, H3 / H4 can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc.

[0079] In one embodiment, please refer to Figure 1 The second groove 24 has a depth of H5 in the first direction, and the negative electrode current collector 21 has a thickness of H6 in the first direction, with 20% ≤ H5 / H6 ≤ 40%.

[0080] It is understandable that when H5 / H6 is less than 20%, the depth of the second groove 24 is small, and the anchoring effect between the second insulating layer 23 and the second groove 24 is not good; when H5 / H6 is greater than 40%, the depth of the second groove 24 is large, which greatly reduces the strength of the negative electrode current collector 21 and easily leads to the current collector breaking. As an example, H5 / H6 can be 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, etc.

[0081] In one embodiment, please refer to Figure 1 The width of the second groove 24 along the direction of the second insulating layer 23 away from the negative electrode active layer 22 is H7, and the width of the second insulating layer 23 along the direction away from the negative electrode active layer 22 is H8, 10%≤H7 / H8≤50%.

[0082] It is understandable that when H7 / H8 is less than 10%, the width of the second groove 24 is small, and the anchoring effect between the second insulating layer 23 and the second groove 24 is not good; when H7 / H8 is greater than 50%, the width of the second groove 24 is large, which greatly reduces the strength of the negative electrode current collector 21 and easily leads to the current collector breaking. As an example, H7 / H8 can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc.

[0083] In one embodiment, the first insulating layer 13 and the positive electrode active layer 12 are disposed at a distance.

[0084] In one embodiment, the second insulating layer 23 is disposed at a distance from the negative electrode active layer 22.

[0085] In one embodiment, the first insulating layer 13 is spaced 30μm-100μm from the positive electrode active layer 12, for example, it can be 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, etc.

[0086] It is understandable that when the distance between the first insulating layer 13 and the positive electrode active layer 12 is less than 30 μm, the first insulating layer 13 will undergo lateral deformation under high pressure, which may squeeze the positive electrode active layer 12 and the electrolyte layer 3, and may cause the edge material of the positive electrode active layer 12 and the electrolyte layer 3 to crack. When the distance between the first insulating layer 13 and the positive electrode active layer 12 is greater than 100 μm, the first insulating layer 13 occupies a large space in the solid-state battery, which will reduce the energy density of the solid-state battery.

[0087] In one embodiment, the second insulating layer 23 is spaced 30μm-100μm from the negative electrode active layer 22, for example, it can be 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, etc.

[0088] It is understandable that when the distance between the second insulating layer 23 and the negative electrode active layer 22 is less than 30 μm, the second insulating layer 23 will undergo lateral deformation under high pressure, which may squeeze the negative electrode active layer 22 and the electrolyte layer 3, and may cause the edge material of the negative electrode active layer 22 and the electrolyte layer 3 to crack. When the distance between the second insulating layer 23 and the negative electrode active layer 22 is greater than 100 μm, the second insulating layer 23 occupies a large space in the solid-state battery, which will reduce the energy density of the solid-state battery.

[0089] In one embodiment, the shortest distance between the circumferential edge of the positive electrode active layer 12 and the circumferential edge of the positive electrode current collector 11 is H9, where H9 > 0.8 mm, and the area of ​​the positive electrode active layer 12 is greater than or equal to 80% of the area of ​​the positive electrode current collector 11.

[0090] It is understood that the first insulating layer 13 is disposed on the circumferential edge of the positive electrode active layer 12. By controlling the spacing between the first insulating layer 13 and the positive electrode active layer 12, controlling the width of the first insulating layer 13 extending beyond the circumferential edge of the positive electrode active layer 12, and controlling the shortest distance (vertical distance) between the circumferential edge of the positive electrode active layer 12 and the circumferential edge of the positive electrode current collector 11, the width of the first insulating layer 13 can be controlled, thereby ensuring the insulation effect of the first insulating layer 13. If the width of the first insulating layer 13 is too narrow, its insulation effect will be poor.

[0091] In one embodiment, the shortest distance between the circumferential edge of the negative electrode active layer 22 and the circumferential edge of the negative electrode current collector 21 is H. 10 H 10 >0.8mm, and the area of ​​the negative electrode active layer 22 is greater than or equal to 80% of the area of ​​the negative electrode current collector 21.

[0092] It is understood that the second insulating layer 23 is disposed around the edge of the negative electrode active layer 22. By controlling the spacing between the second insulating layer 23 and the negative electrode active layer 22, controlling the width of the second insulating layer 23 extending beyond the circumferential edge of the negative electrode active layer 22, and controlling the shortest distance (vertical distance) between the circumferential edge of the negative electrode active layer 22 and the circumferential edge of the negative electrode current collector 21, the width of the second insulating layer 23 can be controlled, thereby ensuring the insulation effect of the second insulating layer 23. If the width of the second insulating layer 23 is too narrow, its insulation effect will be poor.

[0093] In one embodiment, the minimum width by which the circumferential edge of the negative electrode active layer 22 extends beyond the circumferential edge of the positive electrode active layer 12 is 1mm to 3mm, for example, it can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, etc.

[0094] It is understood that the negative electrode active layer 22 includes a negative electrode active material, which is prone to volume change. By making the minimum width of the circumferential edge of the negative electrode active layer 22 exceeding the circumferential edge of the positive electrode active layer 12 1mm~3mm (that is, the vertical distance between the circumferential edge of the negative electrode active layer 22 and the circumferential edge of the positive electrode active layer 12), a margin can be left for the volume change of the negative electrode active material, ensuring the safety of the electrode assembly, and minimizing the margin within the safety threshold, thereby maximizing the energy density of the electrode assembly.

[0095] In one embodiment, please refer to Figure 4 The circumferential edge of the electrolyte layer 3 is flush with the circumferential edge of the negative electrode active layer 22.

[0096] In one embodiment, please refer to Figure 1 and Figure 3 The circumferential edge of the electrolyte layer 3 extends beyond the circumferential edge of the positive electrode active layer 12 and covers the periphery of the positive electrode active layer 12.

[0097] It can be understood that the portion of the circumferential edge of the electrolyte layer 3 that extends beyond the circumferential edge of the positive electrode active layer 12 is the electrolyte layer 3 covering the periphery of the positive electrode active layer 12.

[0098] In one embodiment, please refer to Figure 1 and Figure 4 The circumferential edge of the electrolyte layer 3 extends beyond the circumferential edge of the negative electrode active layer 22 and covers the periphery of the negative electrode active layer 22.

[0099] It can be understood that the portion of the circumferential edge of the electrolyte layer 3 that extends beyond the circumferential edge of the negative electrode active layer 22 is the electrolyte layer 3 covering the periphery of the negative electrode active layer 22.

[0100] For example, please refer to Figure 1 The circumferential edge of the electrolyte layer 3 may extend beyond both the circumferential edge of the positive electrode active layer 12 and the circumferential edge of the negative electrode active layer 22, and cover the periphery of both the positive electrode active layer 12 and the negative electrode active layer 22. The electrolyte layer 3 may include a first electrolyte layer and a second electrolyte layer, which are stacked to form the electrolyte layer 3.

[0101] For example, please refer to Figure 2 The circumferential edge of the electrolyte layer 3 may extend only beyond the circumferential edge of the negative electrode active layer 22 and cover the periphery of the negative electrode active layer 22.

[0102] For example, please refer to Figure 3 The circumferential edge of the electrolyte layer 3 may extend only beyond the circumferential edge of the positive electrode active layer 12 and cover the periphery of the positive electrode active layer 12.

[0103] In one embodiment, the circumferential edge of the electrolyte layer 3 extends beyond the circumferential edge of the positive electrode active layer 12 by a minimum width of 10 μm to 30 μm, for example, it can be 10 μm, 12 μm, 15 μm, 20 μm, 25 μm, 27 μm, 30 μm, etc.

[0104] It is understandable that if the electrolyte layer 3 around the positive electrode active layer 12 is too thin (i.e., the vertical distance between the circumferential edge of the electrolyte layer 3 and the circumferential edge of the positive electrode active layer 12), its buffering effect is poor. When the electrode assembly is under pressure, it does not adequately alleviate the stress on the edge of the positive electrode active layer 12. Furthermore, during later cycles of the electrode assembly, the lateral expansion of the positive electrode active layer 12 may still compress the first insulating layer 13, causing cracks at the edge of the positive electrode active layer 12. If the electrolyte layer 3 around the positive electrode active layer 12 is too thick, it occupies a large space in the solid-state battery, reducing the energy density of the solid-state battery.

[0105] In one embodiment, the circumferential edge of the electrolyte layer 3 extends beyond the circumferential edge of the negative electrode active layer 22 by a minimum width of 10 μm to 30 μm, for example, it can be 10 μm, 12 μm, 15 μm, 20 μm, 25 μm, 27 μm, 30 μm, etc.

[0106] It is understandable that if the electrolyte layer 3 around the negative electrode active layer 22 is too thin (i.e., the vertical distance between the circumferential edge of the electrolyte layer 3 and the circumferential edge of the negative electrode active layer 22), its buffering effect is poor. When the electrode assembly is under pressure, it does not adequately alleviate the stress on the edge of the negative electrode active layer 22. Furthermore, during later cycles of the electrode assembly, the lateral expansion of the negative electrode active layer 22 may still compress the second insulating layer 23, causing cracks at the edge of the positive electrode active layer 12. If the electrolyte layer 3 around the negative electrode active layer 22 is too thick, it occupies a large space in the solid-state battery, reducing the energy density of the solid-state battery.

[0107] In one embodiment, the positive electrode 1 includes a first positive electrode and a second positive electrode, the negative electrode 2 includes a first negative electrode and a second negative electrode, and the electrolyte layer 3 includes a first electrolyte layer and a second electrolyte layer. The first negative electrode, the first electrolyte layer, the first positive electrode, the second positive electrode, the second electrolyte layer, and the second negative electrode are stacked along a first direction.

[0108] As an example, the electrode assembly can be stacked in 5-20 layers in the manner of a first negative electrode, a first electrolyte layer, a first positive electrode, a second positive electrode, a second electrolyte layer, and a second negative electrode.

[0109] Test example: Electrode assemblies with a first insulating layer 13 and a second insulating layer 23 and electrode assemblies without the first insulating layer 13 and the second insulating layer 23 were subjected to cyclic testing. The test results are shown in Table 1.

[0110] Table 1

[0111] As shown in Table 1, by setting the first insulating layer and the second insulating layer, the increase in interface impedance of the electrode assembly can be reduced and the capacity retention of the electrode assembly can be improved. Therefore, the first insulating layer and the second insulating layer can improve the interface separation caused by the volume expansion effect during the cycling process of the electrode assembly.

[0112] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. An electrode assembly, characterized by, include: At least one positive electrode (1), the positive electrode (1) includes a positive current collector (11) and a positive active layer (12) and a first insulating layer (13) disposed on one side of the positive current collector (11), the first insulating layer (13) being disposed on the circumferential edge of the positive active layer (12); At least one negative electrode (2), the negative electrode (2) includes a negative current collector (21) and a negative active layer (22) disposed on one side of the negative current collector (21) and a second insulating layer (23), the second insulating layer (23) is disposed on the edge circumferential of the negative active layer (22), and the end of the second insulating layer (23) away from the negative current collector (21) abuts against the first insulating layer (13); At least one electrolyte layer (3) is disposed between the positive electrode active layer (12) and the negative electrode active layer (22); The positive electrode (1), the negative electrode (2) and the electrolyte layer (3) are stacked along a first direction.

2. The electrode assembly of claim 1, wherein, The first insulating layer (13) extends in a direction away from the positive electrode active layer (12) to a minimum width of 0.1 mm to 0.5 mm beyond the circumferential edge of the positive electrode current collector (11); and / or The second insulating layer (23) extends in a direction away from the negative electrode active layer (22) to the circumferential edge of the negative electrode current collector (21) with a minimum width of 0.1 mm to 0.5 mm.

3. The electrode assembly of claim 1, wherein, The positive current collector (11) is provided with a first groove (14) opened along the first direction, and one end of the first insulating layer (13) is embedded in the first groove (14); and / or The negative electrode current collector (21) is provided with a second groove (24) opened along the first direction, and one end of the second insulating layer (23) is embedded in the second groove (24).

4. The electrode assembly of claim 3, wherein, The depth of the first groove (14) in the first direction is H1, and the thickness of the positive current collector (11) in the first direction is H2, 20%≤H1 / H2≤40%; and / or The width of the first groove (14) along the direction of the first insulating layer (13) away from the positive electrode active layer (12) is H3, and the width of the first insulating layer (13) along the direction away from the positive electrode active layer (12) is H4, 10%≤H3 / H4≤50%; and / or The second groove (24) has a depth of H5 in the first direction, and the negative electrode current collector (21) has a thickness of H6 in the first direction, 20% ≤ H5 / H6 ≤ 40%; and / or The width of the second groove (24) along the direction away from the negative electrode active layer (22) of the second insulating layer (23) is H7, and the width of the second insulating layer (23) along the direction away from the negative electrode active layer (22) is H8, 10%≤H7 / H8≤50%.

5. The electrode assembly of any one of claims 1-4, wherein, The first insulating layer (13) is spaced apart from the positive electrode active layer (12); and / or The second insulating layer (23) is spaced apart from the negative electrode active layer (22).

6. The electrode assembly of claim 5, wherein, The first insulating layer (13) is spaced 30 μm-100 μm from the positive electrode active layer (12); and / or The second insulating layer (23) is spaced 30μm-100μm from the negative electrode active layer (22).

7. The electrode assembly of claim 6, wherein, The shortest distance between the circumferential edge of the positive electrode active layer (12) and the circumferential edge of the positive electrode current collector (11) is H9, H9 > 0.8 mm, and the area of ​​the positive electrode active layer (12) is greater than or equal to 80% of the area of ​​the positive electrode current collector (11); and / or The shortest distance between the circumferential edge of the negative electrode active layer (22) and the circumferential edge of the negative electrode current collector (21) is H. 10 H 10 >0.8mm, and the area of ​​the negative electrode active layer (22) is greater than or equal to 80% of the area of ​​the negative electrode current collector (21).

8. The electrode assembly of claim 5, wherein, The minimum width by which the circumferential edge of the negative electrode active layer (22) extends beyond the circumferential edge of the positive electrode active layer (12) is 1 mm to 3 mm.

9. The electrode assembly of claim 5, wherein, The circumferential edge of the electrolyte layer (3) is flush with the circumferential edge of the negative electrode active layer (22).

10. The electrode assembly of claim 5, wherein, The circumferential edge of the electrolyte layer (3) extends beyond the circumferential edge of the positive electrode active layer (12) and covers the periphery of the positive electrode active layer (12); and / or The circumferential edge of the electrolyte layer (3) extends beyond the circumferential edge of the negative electrode active layer (22) and covers the periphery of the negative electrode active layer (22).

11. The electrode assembly of claim 10, wherein, The circumferential edge of the electrolyte layer (3) extends beyond the minimum width of the circumferential edge of the positive electrode active layer (12) by 10 μm to 30 μm; and / or The circumferential edge of the electrolyte layer (3) extends beyond the minimum width of the circumferential edge of the negative electrode active layer (22) by 10 μm to 30 μm.

12. The electrode assembly of claim 1, wherein, The positive electrode (1) includes a first positive electrode and a second positive electrode, the negative electrode (2) includes a first negative electrode and a second negative electrode, and the electrolyte layer (3) includes a first electrolyte layer and a second electrolyte layer. The first negative electrode, the first electrolyte layer, the first positive electrode, the second positive electrode, the second electrolyte layer and the second negative electrode are stacked along a first direction.

13. A solid state battery, characterized by It includes at least one electrode assembly as described in any one of claims 1-12.

14. An electrical device, characterized by Includes the electrode assembly as described in any one of claims 1-12, and / or the solid-state battery as described in claim 13.

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