Solid-state battery and electric device

Abstract

The utility model provides a solid-state battery and an electric device. The solid-state battery comprises an electrode assembly, the electrode assembly comprises a positive electrode layer, a negative electrode current collector and a solid-state electrolyte layer, and the solid-state electrolyte layer is located between the positive electrode layer and the negative electrode current collector; at least one surface of the negative current collector is provided with a blind hole, and the opening of the blind hole faces the solid electrolyte layer. According to the solid-state battery, the blind holes are formed in the negative current collector, so that lithium ions can be embedded into the blind holes, the embedding amount of the lithium ions in the surface of the negative current collector is reduced, and the influence of volume expansion caused by lithium ion embedding on a contact interface between the surface of a negative pole piece and a solid-state electrolyte layer is reduced; the improvement of the cycle performance of the solid-state battery is promoted.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a solid-state battery and a power utilization device. BACKGROUND

[0002] In recent years, solid-state batteries prepared by using solid-state electrolytes have attracted extensive attention. Solid-state batteries can effectively reduce the risk of flammability and explosiveness caused by high electrolyte content in liquid-state batteries. Moreover, solid-state electrolytes endow solid-state batteries with the characteristics of compact structure, adjustable scale, and great design flexibility, and thus the solid-state batteries can be applied to drive micro electronic devices and can also be applied to the fields of power and energy storage.

[0003] In traditional solid-state batteries, the volume expansion caused by lithium ion intercalation can affect the contact interface between the surface of the negative electrode tab and the solid-state electrolyte layer, and thus affect the cycle performance of the battery. SUMMARY

[0004] The first aspect of the present application provides a solid-state battery, comprising an electrode assembly, the electrode assembly comprising a positive electrode layer, a negative current collector, and a solid-state electrolyte layer, the solid-state electrolyte layer being located between the positive electrode layer and the negative current collector; at least one surface of the negative current collector is provided with a blind hole, and the aperture of the blind hole faces the solid-state electrolyte layer.

[0005] In the above-mentioned solid-state battery, the negative current collector is provided with a blind hole, the existence of the blind hole can promote the intercalation of lithium ions in the blind hole, reduce the intercalation amount of lithium ions on the surface of the negative current collector, reduce the influence of the volume expansion caused by the intercalation of lithium ions on the contact interface between the surface of the negative current collector and the solid-state electrolyte layer, and thus promote the improvement of the cycle performance of the solid-state battery.

[0006] In some embodiments, the aperture of the blind hole is D, and the depth of the blind hole is H1; the aperture of the blind hole represents the maximum distance between two points on the aperture of the blind hole in the cross section perpendicular to the thickness direction of the negative current collector; wherein 0.01≤D / H1≤0.1. When D / H1 is within the range, enough space can be provided for the intercalation of lithium ions, so that more lithium ions can be intercalated in the blind hole. At the same time, when D / H1 is within the range, the intercalation and deintercalation of lithium ions in the blind hole are facilitated, which is beneficial to further improve the cycle performance of the battery.

[0007] In some embodiments, 0.01μm≤D≤1μm.

[0008] In some embodiments, 1μm≤H1≤10μm.

[0009] In some embodiments, the depth of the blind hole is H1, and the thickness of the negative current collector is H2; wherein 0.2≤H1 / H2≤0.95. The ratio of the depth of the blind hole to the thickness of the negative current collector in this range can provide more embedding sites for lithium ions on the basis of maintaining a high intrinsic strength of the negative current collector, further improving the structural stability of the electrode assembly, and thus promoting the improvement of the battery cycle performance.

[0010] In some embodiments, the thickness of the negative current collector is 8 μm to 50 μm.

[0011] In some embodiments, the depth of the blind hole is H1; at the bottom of the blind hole, the thickness of the negative current collector of the blind hole is H3; wherein 0.2≤H1 / (H1+H3)≤0.95. H1 / (H1+H3) in this range can make the negative current collector have a high intrinsic strength, which is conducive to the structural stability of the high electrode assembly and promotes the improvement of the battery cycle performance.

[0012] In some embodiments, 0.5 μm≤H3≤8 μm.

[0013] In some embodiments, the aperture of the blind hole comprises a polygonal aperture.

[0014] In some embodiments, the side length L1 of the polygonal aperture is 0.05 μm to 1 μm. The polygonal aperture with the side length in this range has a relatively appropriate aperture area, which is conducive to the embedding and de-embedding of lithium ions, while the negative current collector can maintain a high intrinsic strength, which is conducive to maintaining a relatively stable structure of the negative current collector.

[0015] In some embodiments, the polygonal aperture comprises a regular polygonal aperture. The regular polygonal aperture can make the shape of the blind hole and the strength of the composite current collector have better consistency, which is conducive to maintaining good structural stability of the electrode assembly.

[0016] In some embodiments, the number of sides of the polygonal aperture is greater than or equal to 3.

[0017] In some embodiments, the number of sides of the polygonal aperture is greater than or equal to 4.

[0018] In some embodiments, the number of sides of the polygonal aperture is greater than or equal to 6.

[0019] In some embodiments, the internal angles of the polygonal aperture are all greater than or equal to 90°. At this time, the lithium ions can be more fully embedded and de-embedded at the internal angles of the blind hole, which is conducive to the improvement of the battery cycle performance.

[0020] In some embodiments, the aperture of the blind hole comprises an arc-shaped aperture.

[0021] In some embodiments, the arc-shaped hole includes one or more of a circular hole and an elliptical hole.

[0022] In some embodiments, the blind holes are multiple, and the multiple blind holes are arranged at intervals.

[0023] In some embodiments, the multiple blind holes are arranged at equal intervals. At this time, lithium ions can be more uniformly embedded in the blind holes of the negative current collector, reducing the risk of lithium dendrite generation and further improving the cycle performance of the battery.

[0024] In some embodiments, the hole of the blind hole includes a polygonal hole, and any two adjacent polygonal holes are arranged with a common side. At this time, the hole walls of multiple blind holes can support each other, so that a sufficient number of blind holes can be arranged on the negative current collector while the negative current collector maintains a high strength, and thus the electrode assembly maintains good structural stability.

[0025] In some embodiments, the polygonal hole includes a regular triangular hole, a rectangular hole, a rhombic hole, a square hole, or a regular hexagonal hole.

[0026] In some embodiments, the minimum distance L2 between the hole walls of two adjacent blind holes is 0.05-1 μm. L2 in this range can make the hole walls of multiple blind holes maintain better mutual support effect, so that the electrode assembly maintains better structural stability.

[0027] In some embodiments, both opposite surfaces of the negative current collector are provided with the blind holes. At this time, both opposite surfaces of the negative current collector can be provided with a solid electrolyte layer.

[0028] In some embodiments, in the thickness direction of the negative current collector, the projections of the blind holes on the opposite surfaces of the negative current collector are staggered or intersected.

[0029] In some embodiments, on the surface of the negative current collector provided with the blind holes, the total area of the hole of the blind hole is S1, and the area of the surface is S2, wherein 0.05≤S1 / S2≤0.95. At this time, the blind hole can provide sufficient space for the embedding of lithium ions, while the negative current collector maintains good intrinsic strength, which is conducive to better consideration of the embedding of lithium ions and the maintenance of structural stability of the electrode assembly.

[0030] In some embodiments, the electrode assembly further includes a lithium-containing metal, and the blind hole is filled with the lithium-containing metal.

[0031] In some embodiments, the solid-state battery includes a full solid-state battery.

[0032] A second aspect of the present application provides a power consuming device including the solid-state battery. BRIEF DESCRIPTION OF DRAWINGS

[0033] For a better description and illustration of the embodiments or examples provided by the present application, reference can be made to one or more of the accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, the presently described embodiments or examples, and the best mode presently understood of these applications. Moreover, in all the drawings, the same reference numbers are used to designate the same components. In the drawings:

[0034] Figure 1 A schematic diagram of an electrode assembly of a solid-state battery according to an embodiment of the present application.

[0035] Figure 2 A schematic diagram of an electrode assembly of a solid-state battery according to another embodiment of the present application.

[0036] Figure 3 A schematic diagram of an electrode assembly of a solid-state battery according to yet another embodiment of the present application.

[0037] Figure 4 A schematic diagram of a negative current collector of a solid-state battery according to an embodiment of the present application.

[0038] Figure 5 A schematic diagram of a negative current collector of a solid-state battery according to another embodiment of the present application.

[0039] Figure 6 A schematic diagram of a solid-state battery according to an embodiment of the present application.

[0040] Figure 7 A schematic diagram of a solid-state battery according to another embodiment of the present application. Figure 6 A schematic diagram of a solid-state battery according to another embodiment of the present application.

[0041] Figure 8 A schematic diagram of a power consuming device using a solid-state battery according to an embodiment of the present application as a power source.

[0042] REFERENCE NUMERALS

[0043] 1. Solid-state battery; 11. Housing; 12. Electrode assembly; 121. Positive electrode layer, 122. Negative current collector; 1221. Blind hole; 123. Solid-state electrolyte layer; 124. Lithium-containing metal; 13. Cover plate; 2. Power consuming device. DETAILED DESCRIPTION

[0044] For the purpose of understanding the present application, the present application will be described more fully below with reference to the accompanying drawings, in which preferred embodiments of the present application are shown as non-limiting examples. For example, there are cases where detailed description of well-known matters, repeated description of substantially identical configurations will be omitted. This is to avoid unnecessary lengthy description and to facilitate understanding by those skilled in the art. In addition, the accompanying drawings and the following description are provided to allow those skilled in the art to sufficiently understand the present application, and are not intended to limit the scope of the present application.

[0045] The "range" disclosed in the present application can be defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The range defined in this way can be inclusive or exclusive of the end values, either end value can be included or excluded independently, and can be arbitrarily combined, i.e., any lower limit can be combined with any upper limit to form a range. For example, if the ranges 60-120 and 80-110 are listed for a particular parameter, it is understood that the ranges 60-110 and 80-120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are also listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In the present application, unless otherwise stated, the numerical range "a-b" represents a shorthand notation for any real combination of integers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein, and "0-5" is just a shorthand notation for these numerical combinations. In addition, when it is stated that a parameter is an integer ≥ 2, it is equivalent to listing the parameter as, for example, integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For example, when it is stated that a parameter is an integer selected from "2-10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0046] In the present application, unless otherwise specified, "about" means within a reasonable range of the number, and the fluctuation range can vary depending on the type and value of the number. For example, a range of ±10%, ±5%, ±2%, ±1%, etc. can be allowed. For example, taking "about 20°C" with an approximation of ±1°C as an example, the approximation values of 19°C, 19.5°C, etc. within the approximation range indicated by "about 20°C" should also be included in the range indicated by "about 20°C".

[0047] In the present application, as related to "a plurality of", "a plurality of", "a plurality of", "several", etc., if there is no special limitation, it means more than 2 or equal to 2 in quantity. For example, "one or more" means one or more than or equal to two. It can be understood that when referring to "any number of" items, it means any suitable combination of items, that is, the combination of "any number of" items is carried out in a way that does not conflict and can implement the present application.

[0048] If there is no special description, all embodiments and optional embodiments of the present application can be combined to form new technical solutions.

[0049] In the present application, referring to "embodiments" means that the specific features, structures or characteristics described in conjunction with the embodiments can be included in at least one embodiment or embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment to other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments. In this paper, "embodiments" have a similar understanding.

[0050] Those skilled in the art can understand that in the method of each embodiment or embodiment, the writing order of each step does not mean a strict execution order and does not constitute any limitation on the implementation process. The detailed execution order of each step should be determined by its function and possible internal logic. If there is no special description, all steps of the present application can be performed in sequence, or randomly, which can be preferably performed in sequence. For example, method M includes steps (a) and (b), which means that the method can include steps (a) and (b) performed in sequence, or steps (b) and (a) performed in sequence. For example, method M also includes step (c), which means that step (c) can be added to method M in any order, for example, method M can include steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0051] In the present application, M (such as m1) means that m1 is a non-limiting example of M, and it can be understood that M is not limited to m1.

[0052] In the present application, "optionally", "optional", "optional" means optional, that is, it means to choose from two parallel schemes of "have" or "have". If there are multiple "optional" in a technical solution, if there is no special description, and there is no contradiction or mutual restriction, each "optional" is independent. If there is no other description, "optionally includes", "optionally contains" and the like are described in the present application, for example, "optionally includes" means "may include or not include".

[0053] In the present application, "and / or" corresponds to any one of the two or more related listed items, or any and all combinations of the related listed items, unless otherwise specified and limited, wherein any and all combinations include any two related listed items, any more related listed items, or all related listed items. For example, "M and / or N" represents a group consisting of M, N, and a combination of M and N. Wherein "including M and / or N" can mean "including M, including N, and including a combination of M and N", or can mean "including M, including N, or including a combination of M and N", which can be properly understood according to the sentence.

[0054] In the present application, "combination thereof", "any combination thereof", "any combination manner thereof", and the like include all suitable combination manners of any two or more of the listed items.

[0055] In the present application, "suitable combination manner", "suitable manner", "any suitable manner", and the like are subject to the implementation of the technical solutions of the present application.

[0056] In the present application, "further", "still further", "in particular", "for example", "such as", "for instance", "for example", and the like are for description purposes, and should not be understood as limiting the scope of protection of the present application.

[0057] In the present application, in "first aspect", "second aspect", and the like, the terms "first", "second", and the like are only for description purposes, and should not be understood as indicating or implying relative importance or quantity, nor should it be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", and the like only serve the purpose of non-exhaustive enumeration description, and should be understood as not constituting a closed limitation on the quantity.

[0058] In the present application, unless otherwise specified and limited, the first feature "on" or "under" the second feature can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. In the present application, unless otherwise specified and limited, the first feature "on" or "under" the second feature can represent the mutual positional relationship of the horizontal height, or can only represent the existence of the attachment relationship without limiting the mutual positional relationship of the horizontal height.

[0059] In the present application, the term "room temperature" generally refers to 4°C to 35°C, and can refer to 20°C ± 5°C. In some embodiments or examples of the present application, room temperature refers to 20°C to 30°C.

[0060] In the present application, if the unit of the data range is only indicated after the right end point, it means that the units of the left end point and the right end point are the same. For example, 3~5h or 3~5h both mean that the units of the left end point "3" and the right end point "5" are h (hour), and both have the same meaning as 3h~5h. In addition, similar descriptions of other parameters such as temperature, size, etc. are also understood in the same way.

[0061] In the present application, the exemplary description such as "in some embodiments (or examples)", "in an embodiment (or example)" and the like can cover but is not limited to the following meanings: these schemes can be combined with other schemes in a suitable manner to form new technical schemes.

[0062] In the present application, unless otherwise stated, the "solid-state battery" provided in the present application refers to a battery in which the electrolyte in the battery includes a solid-state electrolyte. Generally, the solid-state battery includes a positive electrode layer, a solid-state electrolyte layer, and a negative electrode layer. During the charging and discharging process of the battery, active ions are reversibly inserted and extracted between the positive electrode layer and the negative electrode layer. The solid-state electrolyte layer plays a role in conducting ions between the positive electrode layer and the negative electrode layer, and can also isolate the positive electrode layer from the negative electrode layer to prevent short circuiting between the positive and negative electrodes, therefore, the solid-state battery can not be provided with an isolation film in the traditional liquid battery. The solid-state battery uses a non-flammable solid-state electrolyte to replace the organic electrolyte in the traditional liquid battery, greatly improving the safety of the battery.

[0063] In the present application, unless otherwise stated, the "solid-state electrolyte" refers to an electrolyte material or electrolyte substance that exists in a solid state during the storage and preparation of the solid-state battery and the components constituting the solid-state battery, and during the working process of the solid-state battery. It can be understood that the solid-state electrolyte exists in a solid state at room temperature, including but not limited to.

[0064] In the present application, unless otherwise stated, the electrode includes an electrode active material. The electrode active material in the electrode refers to a material that has the ability to reversibly insert and extract active ions. Unless otherwise stated, the negative electrode active material refers to a material that has the ability to reversibly insert and extract active ions for use in the negative electrode. The positive electrode active material refers to a substance that has the ability to reversibly extract and insert active ions for use in the positive electrode. When the solid-state battery is charged, active ions are extracted from the positive electrode and inserted into the negative electrode through the solid-state electrolyte layer; when the solid-state battery is discharged, active ions are extracted from the negative electrode and inserted into the positive electrode. The active ion is not particularly limited, and the active ion can be a lithium ion, which corresponds to a lithium ion solid-state battery.

[0065] Optionally, in the solid-state battery, the negative electrode can not contain a negative electrode active material, thereby obtaining a negative electrode-free solid-state battery.

[0066] During the charging process of the battery, lithium ions are embedded on the surface of the negative electrode sheet to form lithium-containing metal. The lithium-containing metal occupies the space inside the battery, causing the volume expansion of the battery. When the battery contains electrolyte, the presence of the electrolyte can better buffer the volume expansion of the battery. However, for a solid-state battery, due to the lack of effective buffering of the electrolyte, the volume expansion of the battery can easily affect the contact interface between the surface of the electrode sheet and the solid-state electrolyte layer, thereby affecting the cycle performance of the solid-state battery.

[0067] For example, during the charging process of the solid-state battery, the embedding of lithium ions on the negative electrode side can affect the contact interface between the surface of the negative electrode sheet and the solid-state electrolyte layer. In addition, in the solid-state battery, the stress change between the positive electrode layer and the solid-state electrolyte layer caused by the embedding of lithium ions on the negative electrode side can further affect the contact interface between the surface of the positive electrode layer and the solid-state electrolyte layer. Therefore, in the solid-state battery, the embedding of lithium ions on the negative electrode side can affect the contact interface between the surface of the electrode sheet and the solid-state electrolyte layer, thereby affecting the cycle performance of the solid-state battery.

[0068] Therefore, an embodiment of the present application provides a solid-state battery. The solid-state battery comprises an electrode assembly. The electrode assembly comprises a positive electrode layer, a negative current collector, and a solid-state electrolyte layer. The solid-state electrolyte layer is located between the positive electrode layer and the negative current collector. At least one surface of the negative current collector is provided with a blind hole, and the hole of the blind hole faces the solid-state electrolyte layer.

[0069] In the solid-state battery, the blind hole is provided on the negative current collector. The presence of the blind hole can promote the embedding of lithium ions in the blind hole, reduce the embedding amount of lithium ions on the surface of the negative current collector, reduce the influence of the volume expansion caused by the embedding of lithium ions on the contact interface between the surface of the negative current collector and the solid-state electrolyte layer, and further improve the cycle performance of the solid-state battery.

[0070] Further, the negative active layer can not be pre-set on the negative current collector. During the cycle process of the solid-state battery, the presence of the blind hole can promote the embedding of lithium ions in the blind hole to form lithium-containing metal. In addition, due to the large lithium embedding space of the blind hole, the embedding amount of lithium ions on the surface of the negative current collector can be reduced, the influence of the volume expansion caused by the embedding of lithium ions on the contact interface between the negative current collector and the solid-state electrolyte layer can be reduced, and the cycle performance of the solid-state battery can be further improved.

[0071] Further, the reduction of the embedding amount of lithium ions on the surface of the negative current collector can also reduce the influence of the volume expansion on the contact interface between the positive electrode layer and the solid-state electrolyte layer, thereby further improving the cycle performance of the battery.

[0072] Further, the blind hole provided on the negative current collector can buffer the stress generated when lithium ions are inserted, which is conducive to improving the structural stability of the electrode assembly and further promoting the improvement of the cycle performance of the battery.

[0073] Further, the blind hole provided on the negative current collector can make the negative current collector have a larger surface area, increase the contact area of the negative current collector with other materials, provide more insertion sites for lithium ions, and reduce the risk of lithium dendrite growth during charging.

[0074] Further, the blind hole provided on the negative current collector can reduce the weight of the negative current collector, which is conducive to promoting the improvement of the energy density of the solid-state battery.

[0075] As an example, refer to Figure 1 The electrode assembly 12 includes a positive electrode layer 121, a negative current collector 122, and a solid-state electrolyte layer 123. The solid-state electrolyte layer 123 is located between the positive electrode layer 121 and the negative current collector 122. One surface of the negative current collector 122 is provided with a blind hole 1221, and the hole of the blind hole 1221 faces the solid-state electrolyte layer 123.

[0076] It can be understood that, in the electrode assembly 12 shown in Figure 1 , the surface of the negative current collector 122 which is not provided with the blind hole 1221 can also be provided with the solid-state electrolyte layer 123, and the positive electrode layer 121 is also provided on the surface of the solid-state electrolyte layer 123 away from the negative current collector 122.

[0077] In some embodiments, the opposite two surfaces of the negative current collector are both provided with blind holes. At this time, the opposite two surfaces of the negative current collector can both be provided with the solid-state electrolyte layer. Optionally, in the thickness direction of the negative current collector, the projections of the blind holes of the opposite two surfaces of the negative current collector are staggered or intersected.

[0078] As an example, refer to Figure 2The electrode assembly 12 includes a positive electrode layer 121, a negative current collector 122, and a solid electrolyte layer 123. The solid electrolyte layer 123 is located between the positive electrode layer 121 and the negative current collector 122. The opposite two surfaces of the negative current collector 122 are each provided with a blind hole 1221, and the hole opening of the blind hole 1221 faces the solid electrolyte layer 123. The opposite two surfaces of the negative current collector 122 are each provided with the solid electrolyte layer 123, and each solid electrolyte layer 123 is provided with the positive electrode layer 121 away from the surface of the negative current collector 122. In the thickness direction of the negative current collector 122, the projections of the blind holes of the opposite two surfaces of the negative current collector 122 overlap. It can be understood that the projections of the blind holes of the opposite two surfaces of the negative current collector 122 can partially overlap, or the projection of the blind hole of one surface is completely located in the projection of the blind hole of the other surface, or the projections of the blind holes of the opposite two surfaces of the negative current collector 122 completely overlap.

[0079] As an example, please refer to Figure 3 The electrode assembly 12 includes a positive electrode layer 121, a negative current collector 122, and a solid electrolyte layer 123. The solid electrolyte layer 123 is located between the positive electrode layer 121 and the negative current collector 122. The opposite two surfaces of the negative current collector 122 are each provided with a blind hole 1221, and the hole opening of the blind hole 1221 faces the solid electrolyte layer 123. The opposite two surfaces of the negative current collector 122 are each provided with the solid electrolyte layer 123, and each solid electrolyte layer 123 is provided with the positive electrode layer 121 away from the surface of the negative current collector 122. In the thickness direction of the negative current collector 122, the projections of the blind holes of the opposite two surfaces of the negative current collector 122 overlap. It can be understood that the projections of the blind holes of the opposite two surfaces of the negative current collector 122 can partially overlap, or the projection of the blind hole of one surface is completely located in the projection of the blind hole of the other surface, or the projections of the blind holes of the opposite two surfaces of the negative current collector 122 completely overlap.

[0080] It can be understood that the blind hole on the negative current collector means a hole that does not penetrate the negative current collector. At this time, in the case that the blind hole is provided on the opposite two surfaces of the negative current collector, the blind holes of the two surfaces are not connected.

[0081] It can be understood that the electrode assembly further includes lithium-containing metal, and the lithium-containing metal is filled in the blind hole. Further, the lithium-containing metal is provided on the hole bottom and the hole wall of the blind hole. Accordingly, when the solid-state battery is charged, lithium ions are embedded in the blind hole and deposited on the hole bottom and the hole wall of the blind hole.

[0082] It can be understood that the lithium-containing metal includes elemental lithium.

[0083] In some embodiments, the solid-state battery does not contain a negative active material. For example, an active layer is not provided on the surface of the negative current collector of the solid-state battery to form a negative-free solid-state battery. During the charging process of the solid-state battery, lithium ions can be embedded in the blind hole on the negative current collector to form a lithium-containing metal, and during the discharging process of the solid-state battery, lithium ions are generated by the consumption of the lithium-containing metal, thereby completing the embedding and de-embedding of lithium ions in the charging and discharging process of the solid-state battery.

[0084] In some embodiments, the diameter of the blind hole is D, and the depth of the blind hole is H1. The diameter of the blind hole represents the maximum distance between two points on the aperture of the blind hole in the cross section perpendicular to the thickness direction of the negative current collector. Wherein, 0.01≤D / H1≤0.1. D / H1 in this range can provide sufficient space for the embedding of lithium ions, so that more lithium ions can be embedded in the blind hole. At the same time, D / H1 in this range facilitates the embedding and de-embedding of lithium ions in the blind hole, which is conducive to further improving the cycle performance of the battery. Optionally, D / H1 can be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, and any value within the range formed by any two of the above values.

[0085] Please refer to Figures 1-5 , as some examples, which show some schematic diagrams of some solid-state battery electrode assemblies and negative current collectors. Among them, the Z direction represents the thickness direction of the negative current collector, the X direction represents the length direction of the negative current collector, and Y represents the width direction of the negative current collector. At this time, the cross section perpendicular to the thickness direction of the negative current collector can represent the plane composed of the X direction and the Y direction.

[0086] It can be understood that the diameter of the blind hole represents the maximum distance between two points on the aperture of the blind hole in the cross section perpendicular to the thickness direction of the negative current collector, which can represent the maximum distance between two points on the aperture of the blind hole in the plane composed of the X direction and the Y direction. For example, in the case of a circular aperture of the blind hole, the diameter of the blind hole represents the diameter of the circular aperture. In the case of an elliptical aperture of the blind hole, the diameter of the blind hole represents the length of the major axis of the elliptical aperture. When the aperture of the blind hole is polygonal, the diameter of the blind hole represents the maximum distance between two points on the polygonal aperture.

[0087] Optionally, 0.01 μm≤D≤1 μm. For example, the diameter D of the blind hole can be 0.01 μm, 0.02 μm, 0.03 μm, 0.04 μm, 0.05 μm, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, and any value within the range formed by any two of the above values.

[0088] Optionally, 1μm≤H1≤10μm. For example, the depth H1 of the blind hole can be 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, or any value within the range of any two of the above values.

[0089] In some embodiments, the thickness of the negative electrode current collector is H2; wherein, 0.2 ≤ H1 / H2 ≤ 0.95. A ratio of the blind hole depth to the negative electrode current collector thickness within this range provides more insertion sites for lithium ions while maintaining a high intrinsic strength of the negative electrode current collector, further improving the structural stability of the electrode assembly and thus promoting improved battery cycle performance. Optionally, H1 / H2 can be any value within the range of 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.95, or any two of the above values.

[0090] Optionally, the thickness of the negative electrode current collector is 8 μm to 50 μm. More optionally, the thickness of the negative electrode current collector can be 8 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, or any value within the range of any two of the above values.

[0091] In some embodiments, the thickness of the negative electrode current collector without blind holes at the bottom of the blind hole is H3; wherein, 0.2 ≤ H1 / (H1+H3) ≤ 0.95. H1 / (H1+H3) within this range allows the negative electrode current collector to have higher intrinsic strength, which is beneficial to the structural stability of the high-electrode assembly and promotes improved battery cycle performance. Optionally, 0.5μm ≤ H3 ≤ 8μm. Optionally, H1 / (H1+H3) can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.95, or any value within the range of any two of the above values. H3 can be 0.5μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, or any value within the range of any two of the above values.

[0092] Optionally, such as Figure 1 As shown, when a blind hole is provided on one surface of the negative electrode current collector, the thickness of the negative electrode current collector without a blind hole at the bottom of the hole can be represented by the distance between the bottom of the blind hole and the surface of the negative electrode current collector away from the solid electrolyte layer. In this case, optionally, H3 = H2 - H1.

[0093] Optionally, such as Figure 2As shown, the two opposite surfaces of the negative current collector are provided with blind holes, and in the case that the projections of the blind holes of the two opposite surfaces of the negative current collector overlap, the thickness of the negative current collector at the bottom of the blind hole without the blind hole can represent the distance between the bottoms of the blind holes of the two opposite surfaces of the negative current collector. At this time, optionally, H3=H2-H1-H1.

[0094] Optionally, as shown in Figure 3 As shown, one surface of the negative current collector is provided with a blind hole, and in the case that the projections of the blind holes of the two opposite surfaces of the negative current collector are staggered, the thickness of the negative current collector at the bottom of the blind hole without the blind hole can represent the distance between the bottom of the blind hole and the surface of the negative current collector away from the solid electrolyte layer. At this time, optionally, H3=H2-H1.

[0095] In some embodiments, the aperture of the blind hole includes a polygonal aperture. Optionally, the side length L1 of the polygonal aperture is 0.05 μm-1 μm. The polygonal aperture with the side length in this range has a relatively appropriate aperture area, which is conducive to the intercalation and deintercalation of lithium ions, while the negative current collector can maintain a relatively high intrinsic strength, which is conducive to maintaining a relatively stable structure of the negative current collector. Optionally, the side length L1 of the polygonal aperture can be 0.05 μm, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, and any value within the range consisting of any two of the above values.

[0096] Optionally, the polygonal aperture includes a regular polygonal aperture. The regular polygonal aperture can make the shape of the blind hole and the strength of the composite current collector have better consistency, which is conducive to maintaining good structural stability of the electrode assembly. Optionally, the number of sides of the polygonal aperture is greater than or equal to 3. Further optionally, the number of sides of the polygonal aperture is greater than or equal to 4. Further optionally, the number of sides of the polygonal aperture is greater than or equal to 6. Further optionally, the number of sides of the polygonal aperture is less than or equal to 10. For example, the number of sides of the polygonal aperture can be 3, 4, 5, 6, 7, 8, 9, 10, etc.

[0097] In some embodiments, the internal angle of the polygonal aperture is greater than or equal to 90°. At this time, at the internal angle of the blind hole, lithium ions can be more fully intercalated and deintercalated, which is conducive to improving the cycle performance of the battery.

[0098] In some embodiments, the aperture of the blind hole includes an arc-shaped aperture. Optionally, the arc-shaped aperture includes one or more of a circular aperture and an elliptical aperture.

[0099] Please refer again to Figure 4 and Figure 5In some embodiments, the plurality of blind holes are arranged at intervals. Further, the plurality of blind holes are arranged at equal intervals. In this case, lithium ions can be more uniformly embedded in the blind holes of the negative current collector, reducing the risk of lithium dendrite formation and further improving the cycle performance of the battery.

[0100] Please refer again to Figure 5 In some embodiments, the hole openings of the blind holes include polygonal hole openings, and any two adjacent polygonal hole openings are arranged to share a side.

[0101] In this application, sharing a side means that two adjacent polygonal hole openings share a hole wall. Any two adjacent polygonal hole openings sharing a side means that the outer edge of one polygonal hole opening is surrounded by a number of polygonal hole openings equal to the number of sides of the polygonal hole opening. In this case, the hole walls of the plurality of blind holes can support each other, so that a sufficient number of blind holes can be arranged on the negative current collector while maintaining a high strength of the negative current collector, and further maintaining a good structural stability of the electrode assembly.

[0102] Optionally, the polygonal hole openings include equilateral triangle hole openings, rectangular hole openings, rhombus hole openings, square hole openings, or regular hexagon hole openings.

[0103] It can be understood that, in the case of the polygonal hole openings including equilateral triangle hole openings, at least one of the equilateral triangle hole openings is surrounded by three identical equilateral triangle hole openings, i.e., the outer edge of one equilateral triangle blind hole is provided with three blind holes identical to the equilateral triangle blind hole, and one hole wall of the three equilateral triangle blind holes on the outer edge shares a hole wall with the middle equilateral triangle blind hole.

[0104] It can be understood that, in the case of the polygonal hole openings including rectangular hole openings, at least one of the rectangular hole openings is surrounded by four identical rectangular hole openings, i.e., the outer edge of one rectangular blind hole is provided with four blind holes identical to the rectangular blind hole, and one hole wall of the four rectangular blind holes on the outer edge shares a hole wall with the middle rectangular blind hole.

[0105] It can be understood that, in the case of the polygonal hole openings including rhombus hole openings, at least one of the rhombus hole openings is surrounded by four identical rhombus hole openings, i.e., the outer edge of one rhombus blind hole is provided with four blind holes identical to the rhombus blind hole, and one hole wall of the four rhombus blind holes on the outer edge shares a hole wall with the middle rhombus blind hole.

[0106] It can be understood that, in the case of the polygonal hole openings including square hole openings, at least one of the square hole openings is surrounded by four identical square hole openings, i.e., the outer edge of one square blind hole is provided with four blind holes identical to the square blind hole, and one hole wall of the four square blind holes on the outer edge shares a hole wall with the middle square blind hole.

[0107] It can be understood that, in the case where the polygonal orifices include regular hexagonal orifices, at least one outer edge of a regular hexagonal orifice is provided around six identical regular hexagonal orifices, that is, an outer edge of a regular hexagonal blind hole is provided with six blind holes identical to the regular hexagonal blind hole, and one hole wall of the six regular hexagonal blind holes of the outer edge shares one hole wall with the middle regular hexagonal blind hole. At this time, the surface of the negative current collector is a honeycomb structure, lithium ions can be uniformly embedded in the blind holes, and the hole walls of each blind hole can maintain good mutual support effect, which can make the electrode assembly maintain good structural stability.

[0108] In some embodiments, the minimum distance L2 between the hole walls of two adjacent blind holes is 0.05 μm to 1 μm. L2 in this range can make the hole walls of the plurality of blind holes maintain better mutual support effect, so that the electrode assembly maintains better structural stability. Alternatively, L2 can be 0.05 μm, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, and any value within the range formed by any two of the above values.

[0109] In some embodiments, on the surface of the negative current collector provided with the blind holes, the total area of the orifices of the blind holes is S1, and the area of the surface is S2, wherein 0.05≤S1 / S2≤0.95. At this time, the blind holes can provide sufficient space for the embedding of lithium ions, while the negative current collector maintains good intrinsic strength, which is conducive to better consideration of the embedding of lithium ions and the maintenance of the structural stability of the electrode assembly. Alternatively, S1 / S2 can be 0.5, 0.6, 0.7, 0.8, 0.9, 0.95, and any value within the range formed by any two of the above values.

[0110] Alternatively, the material of the negative current collector includes a metal material. Non-limiting examples of the metal material can include one or more of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy.

[0111] Optionally, the negative current collector can also be a composite current collector. The composite current collector can include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. In the negative current collector, the composite current collector can be formed by forming a metal material on the polymer material base layer. Non-limiting examples of the metal material can include one or more of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, and the like. In the negative current collector, non-limiting examples of the polymer material base layer can include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), and the like.

[0112] It can be understood that, in the case of the negative current collector being a composite current collector, the blind hole of the negative current collector can not pass through the metal layer, can pass through the metal layer to the polymer material base layer, and can pass through the metal layer and the polymer material base layer on one side of the current collector without passing through the metal layer on the other side.

[0113] It can be understood that the negative current collector of the present application can be prepared by mechanical processing including but not limited to photolithography, ion etching, acid etching, and the like. For example, a blind hole can be prepared on the surface of a flat negative current collector substrate by photolithography to obtain a negative current collector with a blind hole.

[0114] In some embodiments, the positive electrode layer includes a positive current collector and a positive active layer located on at least one surface of the positive current collector. The positive active material of the positive active layer includes one or more of lithium-containing phosphates and lithium-containing transition metal oxides.

[0115] Optionally, the lithium-containing phosphates can include at least one of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. The lithium-containing phosphates can also include one or more of lithium manganese phosphate and a composite material of lithium manganese phosphate and carbon.

[0116] Optionally, the lithium-containing transition metal oxide includes nickel element. Further, the molar amount of the nickel element accounts for more than 20% of the total molar amount of transition metal elements in the lithium-containing transition metal oxide.

[0117] In some embodiments, the lithium-containing transition metal oxide includes a chemical formula of Li x (Ni a Co b Mn c ) 1-d M d O 2-y A ya material of formula (I), wherein 0.2≤x≤1.2, 0.2≤a≤1, 0≤b≤0.1, 0≤c≤0.1, a+b+c=1, 0≤d<1, 0≤y<2, M comprises one or more of Zr, Sr, B, Sn, Al, Mg, Fe, Cu, V, Ti, Zr, W, Sb, Dy and Te, and A comprises one or more of N, P, S and halogen elements.

[0118] It can be understood that a can be generally used to represent the content of nickel in the lithium-containing transition metal oxide, the greater a is, the higher the content of nickel in the lithium-containing transition metal oxide is, and the smaller a is, the lower the content of nickel in the lithium-containing transition metal oxide is. As some optional examples of a, a can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1 and any value in the range formed by any two of the above values. For example, a can be 0.2-0.5, 0.55-0.75, 0.65-0.85, 0.75-0.95, etc.

[0119] It can be understood that b can be generally used to represent the content of cobalt in the lithium-containing transition metal oxide, the greater b is, the higher the content of cobalt in the lithium-containing transition metal oxide is, and the smaller b is, the lower the content of cobalt in the lithium-containing transition metal oxide is. As some optional examples of b, b can be 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1 and any value in the range formed by any two of the above values. For example, b can be 0.005-0.015, 0.025-0.055, 0.045-0.075, 0.055-0.095, etc.

[0120] It can be understood that c can be generally used to represent the content of manganese in the lithium-containing transition metal oxide, the greater c is, the higher the content of manganese in the lithium-containing transition metal oxide is, and the smaller c is, the lower the content of manganese in the lithium-containing transition metal oxide is. As some optional examples of c, c can be 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1 and any value in the range formed by any two of the above values. For example, c can be 0.005-0.015, 0.025-0.055, 0.045-0.075, 0.055-0.095, etc.

[0121] It can be understood that d can be generally used to represent the content of M element in the lithium-containing transition metal oxide, the greater d represents the higher content of M element in the lithium-containing transition metal oxide, and the smaller d represents the lower content of M element in the lithium-containing transition metal oxide. As some optional examples of d, d can be 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and any value in the range formed by any two of the above values. For example, d can be 0.005-0.015, 0.025-0.055, 0.045-0.075, 0.055-0.095, 0.15-0.55, 0.35-0.85, 0.55-0.95, etc. Optionally, 0≤d≤0.05.

[0122] It can be understood that x can be generally used to represent the content of lithium in the lithium-containing transition metal oxide, the greater x represents the higher content of lithium in the lithium-containing transition metal oxide, and the smaller x represents the lower content of lithium in the lithium-containing transition metal oxide. As some optional examples of x, x can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, and any value in the range formed by any two of the above values. Optionally, x can be 0.25-0.45, 0.35-0.75, 0.55-0.95, 1.05-1.15, etc.

[0123] It can be understood that y can be generally used to represent the content of A element in the lithium-containing transition metal oxide, the greater y represents the higher content of A element in the lithium-containing transition metal oxide, and the smaller y represents the lower content of A element in the lithium-containing transition metal oxide. As some optional examples of y, y can be 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 1.91, 1.92, 1.93, 1.94, 1.95, 1.96, 1.97, 1.98, 1.99, and any value in the range formed by any two of the above values. For example, y can be 0.005-0.015, 0.025-0.055, 0.045-0.075, 0.055-0.095, 0.15-0.55, 0.35-0.85, 0.55-0.95, 1.05-1.15, 1.25-1.55, 1.45-1.95, etc. Optionally, 0≤y≤0.05.

[0124] It is understood that A includes one or more of N, P, S, and a halogen element, wherein the halogen element can be F, CI, Br, etc.

[0125] Optionally, the lithium-containing transition metal oxide includes LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, LiNi 0.5 Co 0.2 Mn 0.3 O2, LiNi 0.5 Co 0.25 Mn 0.25 O2, LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 0.8 Co 0.1 Mn 0.1 O2, LiNi 0.9 Co 0.09 Mn 0.01 O2, LiNi 0.92 Co 0.05 Mn 0.03 O2, LiNi 0.96 Co 0.02 Mn 0.02 O2, LiNi 0.8 Co 0.15 Al 0.05 O2, etc.

[0126] In some embodiments, the positive active material can further include one or more of the following materials: lithium transition metal oxides and their respective modified compounds. Examples of the lithium transition metal oxides can include, but are not limited to, one or more of lithium cobalt oxides (such as LiCoO2), lithium manganese oxides, lithium manganese cobalt oxides, and their modified compounds, etc. Non-limiting examples of the lithium cobalt oxides can include LiCoO2. Non-limiting examples of the lithium manganese oxides can include LiMnO2, LiMn2O4, etc.

[0127] In some embodiments, the positive active layer can further optionally include a binder. As non-limiting examples, the binder can include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, and a fluorine-containing acrylate resin.

[0128] In some embodiments, the positive active layer can further optionally include a conductive agent. As non-limiting examples, the conductive agent can include one or more of super P, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0129] In some embodiments, the positive current collector can employ a metal foil or a composite current collector. For example, as a metal foil, an aluminum foil can be employed. The composite current collector can include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector can be obtained by forming a metal material on a polymer material base material. Non-limiting examples of the metal material in the positive current collector can include one or more of aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, a silver alloy, and the like. Non-limiting examples of the polymer material base material in the positive current collector can include one or more of a polypropylene (PP), a polyethylene terephthalate (PET), a polybutylene terephthalate (PBT), a polystyrene (PS), a polyethylene (PE), and the like.

[0130] In some embodiments, the positive electrode layer can be prepared by dispersing the components described above for preparing the positive electrode layer, such as the positive electrode active material, the conductive agent, the binder, and any other components, in a solvent to form a positive electrode slurry; coating the positive electrode slurry on at least one side surface of the positive current collector, and then drying, cold-pressing, or the like to obtain the positive electrode layer. The solvent can be selected from, but is not limited to, any of the ones described in the foregoing embodiments, such as N-methylpyrrolidone (NMP). The surface of the positive current collector to which the positive electrode slurry is coated can be a single surface of the positive current collector, or both surfaces of the positive current collector.

[0131] It can be understood that the solid-state electrolyte layer includes a solid-state electrolyte. The solid-state electrolyte in the solid-state electrolyte layer can employ a solid-state electrolyte known in the art that can be used in a solid-state battery.

[0132] As non-limiting examples, the solid-state electrolyte can include one or more of a sulfide-based solid-state electrolyte, a halide-based solid-state electrolyte, an oxide-based solid-state electrolyte, a polymer-based solid-state electrolyte, and the like.

[0133] Optionally, the solid-state electrolyte can include, but is not limited to, one or more of an Argyrodite-type sulfide electrolyte and a halide electrolyte. Non-limiting examples of the oxide-based solid-state electrolyte can include a LISICON-type oxide electrolyte (such as γ-Li3PO4, etc.), a NASICON-type oxide electrolyte (such as Li 1+x Al x Ge 2-x (PO4)3, Li 1+x Al x Ti 2-xone or more of Garnet-type (e.g., Li7La3Zr2O12, etc.), Perovskite-type oxide electrolyte (e.g., Li 3x La 2 / 3-x TiO3, etc., 0≤x≤0.5, etc. Non-limiting examples of sulfide-based solid-state electrolytes can include one or more of Li 10 GeP2S 12 , Li2S-P2S5, Argyrodite-type (e.g., Li6PS5Cl, Li 5.5 PS 5.5 Cl 1.5 , etc. Non-limiting examples of halide-based solid-state electrolytes can include one or more of Li3InCl6, Li3YCl6, Li3ScCl6, Li3ErCl6, Li2ZrCl6, etc.

[0134] The solid-state electrolyte layer can be prepared by a dry method. Alternatively, the solid-state electrolyte layer can be prepared by pressing a solid-state electrolyte material into a solid-state electrolyte film. Alternatively, the solid-state electrolyte layer can be formed by pressing a composition of the solid-state electrolyte layer on an electrode sheet. Alternatively, the solid-state electrolyte film can also be prepared by a combination of fiberization and calendering, melt extrusion, spray method, etc.

[0135] The solid-state electrolyte layer can also be prepared by a wet method, using an electrolyte slurry including at least a solid-state electrolyte and an organic solvent, and usually one or more of a binder and a dispersant.

[0136] In some embodiments, the solid-state electrolyte layer can have a thickness of 0.1 μm to 1000 μm, optionally 10 μm to 150 μm, 100 μm to 800 μm, 500 μm to 800 μm, etc.

[0137] In some embodiments, the solid-state battery includes an all-solid-state battery.

[0138] In the present application, unless otherwise specified, an "all-solid-state battery" refers to a solid-state battery in which all electrolytes in the battery are solid-state electrolytes, and no liquid electrolyte is provided in the battery, and thus can be referred to as an "all-solid-state battery".

[0139] The shape of the solid-state battery is not particularly limited in the present application, and can be cylindrical, square, or any other shape. For example, Figure 6 is a square solid-state battery 1 as an example.

[0140] In some embodiments, referring to Figure 7The outer package can include a housing 11 and a cover plate 13. The housing 11 can include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity. The housing 11 has an opening communicating with the receiving cavity, and the cover plate 13 can be arranged on the opening to close the receiving cavity. The electrode assembly 12 is packaged in the receiving cavity. The number of electrode assemblies 12 contained in the solid-state battery 1 can be one or more, which can be selected by those skilled in the art according to actual needs.

[0141] In some embodiments, the solid-state battery can be a battery cell, a battery module, or a battery pack.

[0142] The battery module includes at least one solid-state battery. The number of solid-state batteries contained in the battery module can be one or more, which can be selected by those skilled in the art according to the application and capacity of the battery module.

[0143] In the battery module, the plurality of solid-state batteries can be arranged in sequence along the length direction of the battery module. Of course, other arbitrary arrangements can also be used. Further, the plurality of solid-state batteries can be fixed by fasteners.

[0144] Optionally, the battery module can further include a housing having a receiving space, and the plurality of solid-state batteries are received in the receiving space.

[0145] In some embodiments, the battery module can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be one or more, which can be selected by those skilled in the art according to the application and capacity of the battery pack.

[0146] The battery pack can include a battery box and a plurality of battery modules arranged in the battery box. The battery box includes an upper box body and a lower box body, and the upper box body can be arranged on the lower box body to form a closed space for receiving the battery modules. The plurality of battery modules can be arranged in the battery box in any manner.

[0147] In addition, the present application also provides a power utilization device, which includes the solid-state battery provided by the present application. The solid-state battery can be used as a power source of the power utilization device, or as an energy storage unit of the power utilization device. The power utilization device can include a mobile device, an electric vehicle, an electric train, a ship and a satellite, an energy storage system, etc., but is not limited thereto. The mobile device can be a mobile phone, a notebook computer, etc., for example; the electric vehicle can be a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc., but is not limited thereto.

[0148] As the power utilization device, the solid-state battery can be selected according to the use requirements thereof.

[0149] Figure 8The power consuming device 2 is an example. The power consuming device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. In order to meet the requirements of high power and high energy density of the power consuming device for the battery, a battery pack or a battery module can be used.

[0150] The device as another example can be a mobile phone, a tablet computer, a notebook computer, etc. The device usually requires thinning, and a battery can be used as a power source.

[0151] The technical features of the above-described embodiments can be combined in any manner. In order to make the description simple, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combinations of the technical features do not contradict, they should be considered as the scope of the present disclosure.

[0152] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A solid-state battery, characterized by, The electrode assembly comprises a positive electrode layer, a negative electrode current collector, and a solid-state electrolyte layer between the positive electrode layer and the negative electrode current collector; at least one surface of the negative electrode current collector is provided with a blind hole, and an opening of the blind hole faces the solid-state electrolyte layer.

2. The solid-state battery of claim 1, wherein, A diameter of the blind hole is D, and a depth of the blind hole is H1; the diameter of the blind hole is represented on a cross section perpendicular to a thickness direction of the negative electrode current collector, and represents a maximum distance between two points on the opening of the blind hole; and 0.01≤D / H1≤0.

1.

3. The solid-state battery of claim 2, wherein, 0.01 μm≤D≤1 μm; and / or, 1 μm≤H1≤10 μm.

4. The solid-state battery according to any one of claims 1 to 3, characterized by, The depth of the blind hole is H1, and the thickness of the negative electrode current collector is H2; and 0.2≤H1 / H2≤0.

95.

5. The solid-state battery according to any one of claims 1 to 4, characterized by, The thickness of the negative electrode current collector is 8 μm~50 μm.

6. The solid-state battery according to any one of claims 1 to 5, characterized by, The depth of the blind hole is H1; and at a bottom of the opening of the blind hole, a thickness of the negative electrode current collector not provided with the blind hole is H3; and 0.2≤H1 / (H1+H3)≤0.

95.

7. The solid-state battery of claim 6, wherein, 0.5 μm≤H3≤8 μm.

8. The solid-state battery according to any one of claims 1 to 7, characterized by, The opening of the blind hole comprises a polygonal opening.

9. The solid-state battery of claim 8, wherein, A side length L1 of the polygonal opening is 0.05 μm~1 μm.

10. The solid-state battery of any one of claims 8-9, wherein, The polygonal opening comprises a regular polygonal opening.

11. The solid-state battery according to any one of claims 8 to 10, characterized in that, The number of sides of the polygonal opening is greater than or equal to 3.

12. The solid-state battery according to any one of claims 8 to 11, characterized in that, The number of sides of the polygonal opening is greater than or equal to 4.

13. The solid-state battery according to any one of claims 8 to 12, characterized in that, The number of sides of the polygonal opening is greater than or equal to 6.

14. The solid-state battery of any one of claims 8-13, wherein, Internal angles of the polygonal opening are all greater than or equal to 90°.

15. The solid-state battery of any one of claims 1-7, wherein, The opening of the blind hole comprises an arc-shaped opening.

16. The solid-state battery of claim 15, wherein, The arc-shaped opening comprises one or more of a circular opening and an elliptical opening.

17. The solid-state battery of any one of claims 1-16, wherein, The blind hole is multiple, and the multiple blind holes are arranged at intervals; optionally, the multiple blind holes are arranged at equal intervals.

18. The solid-state battery of claim 17, wherein, The opening of the blind hole comprises a polygonal opening, and any two adjacent polygonal openings are arranged to share a side.

19. The solid-state battery of claim 18, wherein, The polygonal opening comprises a regular triangle opening, a rectangle opening, a rhombus opening, a square opening, or a regular hexagon opening.

20. The solid-state battery of any one of claims 17-19, wherein, In two adjacent blind holes, a minimum distance L2 between hole walls of the two blind holes is 0.05 μm~1 μm.

21. The solid-state battery of any one of claims 1-20, wherein, Both of the opposite surfaces of the negative electrode current collector are provided with the blind hole.

22. The solid-state battery of claim 21, wherein, In a thickness direction of the negative electrode current collector, projections of the blind holes on the opposite surfaces of the negative electrode current collector are staggered or intersected.

23. The solid-state battery of any one of claims 1-22, wherein, On a surface of the negative electrode current collector provided with the blind hole, a total area of the openings of the blind holes is S1, and an area of the surface is S2; and 0.05≤S1 / S2≤0.

95.

24. The solid-state battery of any one of claims 1-23, wherein, The electrode assembly further comprises lithium-containing metal, and the lithium-containing metal is filled in the blind hole.

25. The solid-state battery of any one of claims 1-24, wherein, The solid-state battery comprises a full solid-state battery.

26. An electrical device, comprising: The solid-state battery comprises any one of claims 1~25.

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