Solid-state battery, preparation method thereof and electric equipment

Abstract

The embodiment of the invention provides a solid-state battery and electric equipment, the solid-state battery provided by the embodiment of the invention comprises a positive pole piece, a solid-state electrolyte layer and a negative pole piece, the solid-state electrolyte layer is filled between the positive pole piece and the negative pole piece, and the solid-state electrolyte layer is filled between the positive pole piece and the negative pole piece. The edges of the positive pole piece and the negative pole piece are filled with sealing edges, and the sealing edges are made of ceramic particles and insulation paste. Wherein the edges of the positive pole piece and the negative pole piece are filled with sealing edges formed by ceramic particles and insulation paste, the ceramic particles can play a supporting and insulating role in the pressing process, and the insulation paste can prevent the ceramic particles from overflowing and falling off, so that the yield of pole core forming and manufacturing is improved, meanwhile, the pressed ceramic does not expand after being heated, and the service life of the pole core is prolonged. And the problems of edge collapse, material falling, short circuit and other risks of the existing solid-state battery can be effectively improved.

Description

A solid-state battery, its preparation method, and electrical equipment thereof Technical Field

[0001] This invention relates to the field of battery manufacturing technology, and in particular to a solid-state battery, its preparation method, and electrical equipment. Background Technology

[0002] Currently, due to their non-flammable properties and the ability to achieve high specific capacity anodes, which is beneficial for improving battery energy density, all-solid-state batteries have attracted widespread attention in the industry.

[0003] In the traditional battery manufacturing process, in order to meet the process accuracy tolerance requirements of the stacking / winding process and avoid the risk of short circuit due to edge misalignment, the battery design adopts the design concept of negative-to-positive, that is, the size of the negative electrode coating is wider than the positive electrode coating area in all four directions, resulting in a so-called overhang area.

[0004] However, in order to form a tight packing and contact between solid-state battery material particles, the manufacturing process of all-solid-state batteries generally includes a high-pressure molding process, and they often need to be used under constrained conditions. Overhang design increases the risk of edge collapse, material loss, and short circuits in solid-state batteries during high-pressure molding and use. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a solid-state battery and an electrical device to solve the problems of edge collapse, material loss and short circuit in existing solid-state batteries.

[0006] To solve the above problems, the present invention is achieved through the following technical solution:

[0007] The present invention proposes a solid-state battery, comprising a positive electrode, a solid electrolyte layer and a negative electrode, wherein the solid electrolyte layer is filled between the positive electrode and the negative electrode, and the edges of the positive electrode and the negative electrode are filled with sealing edges, the sealing edges being made of ceramic particles and insulating adhesive.

[0008] Furthermore, in the solid-state battery, the particle size of the ceramic particles is 1–50 μm.

[0009] Furthermore, in the solid-state battery, the compaction density of the ceramic layer is 3 g / m³. 3 ~4g / m 3 .

[0010] Furthermore, in the solid-state battery, the insulating adhesive is at least one of PET insulating adhesive, polyimide, and polytetrafluoroethylene.

[0011] Furthermore, in the solid-state battery, the sealing edge includes a ceramic layer and an insulating adhesive layer, the ceramic layer fills the edge recesses of the positive electrode and the negative electrode, and the insulating adhesive layer at least covers the ceramic layer.

[0012] Furthermore, in the solid-state battery, the ceramic layer fills the recesses between the first electrode and the second electrode, wherein the first electrode is the smaller of the positive and negative electrode in terms of length and width, and the second electrode is the larger of the positive and negative electrode in terms of length and width.

[0013] Furthermore, in the solid-state battery, the thickness of the insulating adhesive layer in the direction perpendicular to the electrode stacking is 5–50 μm.

[0014] Furthermore, in the solid-state battery, the negative electrode has a cantilevered region extending beyond the positive electrode, and the solid electrolyte layer covers the cantilevered region.

[0015] Furthermore, in the solid-state battery, the width of the cantilevered region is 0.2–10 mm.

[0016] This invention also proposes a method for preparing a solid-state battery, comprising:

[0017] The positive electrode, solid electrolyte layer and negative electrode are stacked and pre-pressed to obtain the first battery precursor;

[0018] The edges of the first battery precursor are filled with ceramic particles and insulating adhesive to form the second battery precursor.

[0019] The second battery precursor is encapsulated to obtain a solid-state battery.

[0020] Further, the positive electrode, solid electrolyte layer, and negative electrode are stacked and pre-pressed to obtain the first battery precursor, comprising:

[0021] A positive electrode, a solid electrolyte layer, and a negative electrode are stacked and pre-pressed to obtain a first battery precursor including the positive electrode, the solid electrolyte layer, and the negative electrode, wherein the solid electrolyte layer is filled between the positive electrode and the negative electrode.

[0022] A second battery precursor is formed by filling the edges of the first battery precursor with ceramic particles and insulating adhesive, comprising:

[0023] By filling the edges of the first battery precursor with ceramic particles and insulating adhesive, a second battery precursor with a sealed edge at the edges of the positive electrode and the negative electrode is obtained.

[0024] Furthermore, in the preparation method, filling the edges of the first battery precursor with ceramic particles and insulating adhesive includes:

[0025] A ceramic layer is formed by filling the edge of the first battery precursor with ceramic particles.

[0026] The ceramic layer is at least covered with insulating adhesive to form an insulating adhesive layer.

[0027] Furthermore, in the preparation method, filling the edges of the first battery precursor with ceramic particles includes:

[0028] The ceramic particles are filled into the edge of the first battery precursor by ultrasonic vibration.

[0029] Furthermore, in the preparation method, the pre-compression temperature is 80–100°C and the pressure is 10–20 MPa; and / or

[0030] In the ultrasonic vibration, the dominant frequency of the ultrasonic wave is 20–40 kHz.

[0031] Furthermore, in the preparation method, the positive electrode sheet, the solid electrolyte layer, and the negative electrode sheet are stacked, including:

[0032] The solid electrolyte layer is configured to cover both sides of the negative electrode sheet to form a negative electrode composite sheet;

[0033] The negative electrode composite sheet is stacked with the positive electrode sheet such that the edge of the negative electrode composite sheet extends beyond the positive electrode sheet.

[0034] Furthermore, in the preparation method, the second battery precursor is encapsulated, including:

[0035] The second battery precursor is encapsulated with an encapsulation film, then isostatically pressed, and finally the encapsulation film is removed.

[0036] The present invention also proposes an electrical device, which includes the solid-state battery described above, or a solid-state battery prepared by the preparation method described above.

[0037] Compared with the prior art, the embodiments of the present invention have the following advantages:

[0038] In this embodiment of the invention, the provided solid-state battery includes a positive electrode, a solid electrolyte layer, and a negative electrode. The solid electrolyte layer is filled between the positive and negative electrode, and the edges of the positive and negative electrode are filled with a sealing edge formed by ceramic particles and insulating adhesive. The ceramic particles can provide support and insulation during the pressing process, while the insulating adhesive can prevent the ceramic particles from overflowing or falling off, thereby improving the yield of the electrode core forming process. At the same time, the pressed ceramic does not expand due to heat, which can effectively improve the problems of edge collapse, material loss, and short circuit in existing solid-state batteries, and can significantly improve the performance of the battery cell.

[0039] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0040] Figure 1 is a schematic diagram of the solid-state battery provided in an embodiment of the present invention;

[0041] Figure 2 is a sectional view along direction A in Figure 1;

[0042] Figure 3 is a sectional view along direction B in Figure 1;

[0043] Figure 4 is a schematic diagram of the pre-compression effect of the laminated electrode core;

[0044] Figure 5 is a schematic diagram of the electrode core effect after ceramic particles are filled;

[0045] Figure 6 is a schematic diagram of the electrode core effect after the insulating adhesive layer is pasted on;

[0046] Figure 7 is a schematic diagram of a device that uses ultrasonic vibration to fill ceramic particles.

[0047] Figure 8 is a schematic diagram of the effect of heat sealing the electrode core using aluminum-plastic film;

[0048] Figure 9 is a schematic diagram of the isostatic pressing process of the battery cell.

[0049] Figure 10 is a schematic diagram of the ultrasonic device for vibrating and filling ceramic particles. Detailed Implementation

[0050] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] In existing technologies, in order to form a tight packing and contact between solid particles, all-solid-state batteries generally include a high-pressure molding process in their manufacturing process, and they often need to be used under constrained conditions. If the overhang design in traditional battery manufacturing is still used, it will increase the risk of edge collapse, material loss, and short circuits in solid-state batteries during high-pressure molding and use.

[0052] To address the aforementioned problems, this invention provides a solid-state battery, as shown in Figures 1-3, comprising a positive electrode 11, a solid electrolyte layer 12, and a negative electrode 13. The solid electrolyte layer 12 is filled between the positive electrode 11 and the negative electrode 13, and the edges of the positive electrode 11 and the negative electrode 13 are filled with sealing edges 14. The material of the sealing edges 14 includes ceramic particles and insulating adhesive.

[0053] In this process, the edges of the positive and negative electrode sheets are filled with a sealing edge formed by ceramic particles and insulating adhesive. The ceramic particles play a supporting and insulating role during the pressing process, preventing the risk of edge collapse and material loss during high-voltage molding and use of solid-state batteries. The insulating adhesive can bond the ceramic particles together, effectively preventing the ceramic particles from overflowing or falling off, thereby improving the yield of electrode core molding. At the same time, the pressed ceramic does not expand due to heat, which can greatly improve the performance of the battery cell.

[0054] Therefore, the solid-state battery provided by this invention can effectively improve the problems of edge collapse, material loss, and short circuits in existing solid-state batteries.

[0055] Understandably, in order to facilitate connection with external circuits, the solid-state battery also includes tabs, specifically including a positive tab 151 connected to the positive electrode 11 and a negative tab 152 connected to the negative electrode 13.

[0056] In this embodiment of the invention, the particle size of the ceramic particles is closely related to the compactness and support strength of the sealing edge. Optionally, if the particle size of the ceramic particles is too large, the gap between the ceramic particles will be too large, resulting in poor compactness of the filling. During the isostatic pressing process, there is a risk of short circuit caused by the penetration of positive and / or negative electrode materials. If the particle size of the ceramic particles is too small, although it is beneficial to the filling of materials, it will weaken the support strength of the sealing edge and also affect the compatibility with the electrode active material layer.

[0057] Optionally, in one embodiment, the ceramic particles may specifically be alumina ceramics, silicon nitride ceramics, silicon carbide ceramics, zirconia ceramics, boron nitride ceramics, barium titanate ceramics, boronite, etc.

[0058] Optionally, in one embodiment, the particle size of the ceramic particles is 1–50 μm, which can effectively achieve an isolation effect during isostatic pressing. The particle size refers to the median particle size (D50), also known as the volume average particle size, which represents the particle size corresponding to a cumulative volume distribution percentage of 50% of the material. The particle size of the ceramic particles can be measured using a laser force meter. Optionally, the particle size of the ceramic particles can be one or any two of the following: 1 μm, 3 μm, 5 μm, 10 μm, 20 μm, 30 μm, and 50 μm. Preferably, the particle size of the ceramic particles is 10–50 μm.

[0059] Optionally, in one embodiment, the insulating adhesive can be polyethylene terephthalate (PET) insulating adhesive, polyimide, polytetrafluoroethylene, etc., which can both tightly bond ceramic particles and maintain good insulation and heat resistance.

[0060] Optionally, in one embodiment, the ceramic particles and insulating adhesive are evenly distributed in the sealing edge, that is, the sealing edge is formed by uniformly mixing ceramic particles and insulating adhesive and then curing them.

[0061] In this embodiment, insulating adhesive is used to uniformly bond ceramic particles, further enhancing the overall structural strength of the sealing edge.

[0062] Alternatively, in another embodiment, as shown in Figures 2 and 3, the sealing edge 14 includes a ceramic layer 141 and an insulating adhesive layer 142. The ceramic layer 141 fills the edge recesses of the positive electrode and the negative electrode, and the insulating adhesive layer 142 at least covers the ceramic layer 141.

[0063] In this embodiment, the insulating adhesive layer includes insulating adhesive, that is, the insulating adhesive layer is formed by the insulating adhesive, and the insulating adhesive layer completely covers the ceramic layer formed by the ceramic particles, thereby sealing the ceramic particles and preventing the ceramic particles from falling off during the assembly and production process.

[0064] The edge pits of the positive and negative electrode plates refer to the gaps that form at the edges when the positive and negative electrode plates are stacked due to differences in size or uneven thickness. These gaps may contain solid electrolytes or non-solid electrolytes.

[0065] In this embodiment, the ceramic layer 141 is mainly made of ceramic particles, that is, the ceramic layer 141 is formed by the accumulation of ceramic particles, without any additional liquid binder, which can solve the problem of liquid flow and penetration.

[0066] Optionally, the ceramic layer 141 mainly contains ceramic particles with a mass ratio of more than 90%. Within this range, it can provide good support and also reduce the problem of liquid flow and penetration during battery fabrication.

[0067] Optionally, in one embodiment, the compaction density of the ceramic layer is 3 g / m³. 3 ~4g / m 3 Its density and supporting strength are excellent, effectively preventing short circuits caused by material penetration during isostatic pressing, as well as collapse and material loss during isostatic pressing or use. Optionally, in some embodiments, the compaction density of the above-mentioned ceramic particles is 3 g / m³. 3 3.4g / m 3 3.5g / m 3 4g / m 3 The range of one or any two of them.

[0068] The test method for compaction density is as follows: the compaction density of the ceramic layer is tested according to the national standard GB / T44330-2024.

[0069] Optionally, in one specific embodiment, the ceramic layer fills the recess between the first electrode and the second electrode, wherein the first electrode is the smaller of the positive and negative electrodes in terms of length and width, and the second electrode is the larger of the positive and negative electrodes in terms of length and width.

[0070] In this embodiment, by filling the ceramic layer around the smaller electrode in the positive and negative electrode sheets, the ceramic particles can play a supporting and insulating role during the pressing process, avoiding the risk of the larger electrode sheet's edges collapsing or falling off during the pressing process, which could lead to a short circuit in the battery.

[0071] Optionally, in one specific embodiment, the thickness of the insulating adhesive layer in the direction perpendicular to the electrode stacking is 5 to 50 μm, which can effectively seal and encapsulate the ceramic particles. For example, the thickness of the insulating adhesive layer can be one or any two of the following: 5 μm, 6 μm, 8 μm, 10 μm, 15 μm, 20 μm, 30 μm, 40 μm, and 50 μm.

[0072] In this embodiment of the invention, the width of the insulating adhesive layer is equal to the sum of the thicknesses of the positive electrode, the solid electrolyte layer, and the negative electrode, which is consistent with the thickness of the battery cell formed by stacking the positive electrode, the solid electrolyte layer, and the negative electrode.

[0073] In this embodiment, a C-type adhesive applicator can be used for pre-applying adhesive, and then a roller can be used to apply slight pressure so that the insulating adhesive layer covers the ceramic particles and fits tightly against the side of the battery cell.

[0074] Optionally, in one specific embodiment, the negative electrode sheet has a cantilevered area 131 that extends beyond the edge of the positive electrode sheet. The solid electrolyte layer covers the cantilevered area, that is, the solid electrolyte layer completely covers both sides of the negative electrode sheet, presenting a state in which the negative electrode sheet wraps around the positive electrode sheet, which can effectively prevent short circuits between the positive and negative electrodes.

[0075] In this specific embodiment, because the positive electrode, solid electrolyte layer and negative electrode are stacked, a gap will be formed in the cantilever area between two adjacent negative electrode sheets. The sealing edge formed by ceramic particles and insulating adhesive will fill the gap, which not only ensures the excellent insulation capability of the battery cell and avoids the interface penetration problem of liquid filler, but also plays the role of insulation and edge support during isostatic pressing. This effectively avoids the collapse and bending of the battery cell edge during isostatic pressing and the short circuit caused by material loss. It is also less likely to cause thermal expansion problems during subsequent charging and discharging.

[0076] Optionally, in one embodiment, the width of the cantilevered area is 0.2–10 mm, which is the distance between the side of the cantilevered area furthest from the positive electrode and the side closest to the positive electrode. Setting the width of the cantilevered area to 0.2–10 mm not only effectively isolates the positive and negative electrodes, preventing short circuits between them, but also ensures that the cantilevered area itself has sufficient structural strength to prevent bending. For example, the width of the cantilevered area is one or any two of the following: 0.2 mm, 0.3 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 5 mm, and 10 mm.

[0077] The solid electrolyte layer is disposed between the positive and negative electrode plates, serving to isolate electron transport between them and to conduct lithium ions. Optionally, as shown in Figure 2, the thickness of the solid electrolyte layer is 5µm to 800µm. This not only effectively reduces the risk of short circuits between the positive and negative electrode plates but also avoids excessive impedance, which could affect battery performance and reduce battery energy density. Optionally, in one specific embodiment, the thickness of the solid electrolyte layer is 10µm to 30µm, for example, a value within the range of 10µm, 15µm, 20µm, 25µm, and 30µm, or any combination thereof.

[0078] Optionally, in one embodiment, the solid electrolyte layer includes a solid electrolyte, which is selected from one or more of oxide solid electrolytes, sulfide solid electrolytes, and halide solid electrolytes.

[0079] Optionally, in one specific embodiment, the oxide solid electrolyte is selected from Li7La3Zr2O. 12 Li 10 One or more of Al(Ge,Si)2(PO4)7, the sulfide solid electrolyte is Li6PS5X, where X is selected from one or more of Cl, Br, and I, and the halide solid electrolyte is selected from one or more of Li3InCl6, Li2ZrO4, and Li3YCl6.

[0080] In this embodiment of the invention, the positive electrode sheet includes a positive current collector and a positive active material layer disposed on the positive current collector. The positive active material layer includes a positive active material, a solid electrolyte, a conductive agent, and a polymer binder.

[0081] The aforementioned positive electrode active materials include one or more of the following: olivine-based, layered oxide-based, spinel-based, sulfur-based, and sulfide-based positive electrode materials. Examples of olivine-based materials include LiFePO4; layered oxide-based materials include lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), or LiCoO2; and spinel-based materials include LiMn2O4 and Li4Ti5O4. 12 The cathodes are composed of sulfur and sulfide cathodes such as S8, FeS2, and CuS; the conductive agent is a commonly used conductive agent for cathodes, such as acetylene black, carbon nanotubes, carbon fibers, and carbon black; the solid electrolyte is selected from one or more of oxide solid electrolytes, sulfide solid electrolytes, and halide solid electrolytes; the polymer binder can be one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), polyacrylate, polyacrylic acid (PAA), alkyl cellulose, and polyethylene oxide (PEO), hydrogenated nitrile rubber, etc.

[0082] In some embodiments, the positive electrode sheet is prepared as follows: the components used to prepare the positive electrode sheet, such as the positive active material, binder and any other components, are dispersed in a solvent such as N-methylpyrrolidone to form a positive electrode slurry; the positive electrode slurry is coated on both sides of a positive electrode current collector such as an aluminum foil; after baking, rolling, cutting and other processes, the positive electrode sheet can be obtained.

[0083] In this embodiment of the invention, the negative electrode sheet includes a negative current collector and a negative active material layer disposed on the negative current collector. The negative active material layer contains a negative active material, which can be a negative active material used in batteries, capable of inserting and extracting metal ions (such as lithium ions), for example selected from metal negative electrode materials or non-metal negative electrode materials. The metal negative electrode material is preferably lithium metal or lithium metal alloy. The non-metal negative electrode material is preferably any one or a combination of at least two of hard carbon, soft carbon, graphite, silicon suboxide, silicon-carbon composite, Si, and silicon alloy.

[0084] Optionally, in one embodiment, when the above-mentioned negative electrode active material is selected from non-metallic negative electrode materials, the above-mentioned negative electrode sheet further includes a conductive agent, a binder, and a solid electrolyte. The conductive agent is selected from at least one of acetylene black, Super P, Super S, graphene, carbon fiber, carbon nanotubes, and Ketjen black. The binder is selected from at least one of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polytetrafluoroethylene, polyacrylonitrile, polypropylene carbonate, styrene-butadiene rubber, nitrile rubber, sodium carboxymethyl cellulose, polyethylene oxide, and ethylene oxide-propylene oxide copolymer. The solid electrolyte is selected from one or more of oxide solid electrolytes, sulfide solid electrolytes, and halide solid electrolytes.

[0085] Optionally, in one embodiment, the aforementioned negative electrode active material layer further includes a plasticizer, wherein the plasticizer is selected from at least one of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol dimethyl ether, tetrapropylene glycol dimethyl ether, 1,3-dioxolane, 1,4-dioxane, propylene carbonate, ethylene carbonate, diethyl carbonate or dimethyl carbonate, succinate, and adiponitrile.

[0086] In some embodiments, the negative electrode sheet is prepared as follows: the components used to prepare the negative electrode sheet, such as the negative electrode active material, binder and conductive agent, are dispersed in a solvent such as deionized water to form a negative electrode slurry; the negative electrode slurry is coated on both sides of a negative electrode current collector such as copper foil; after baking, rolling, cutting and other processes, the negative electrode sheet can be obtained.

[0087] In practical applications, the negative electrode, solid electrolyte layer and positive electrode are stacked in sequence, and then sealed with a sealing edge formed by ceramic particles and insulating adhesive, followed by secondary sealing and sorting, to obtain the above-mentioned solid-state battery.

[0088] This invention also proposes a method for preparing a solid-state battery, comprising steps 101 to 103:

[0089] Step 101: Stack the positive electrode, solid electrolyte layer and negative electrode and pre-press them to obtain the first battery precursor.

[0090] In step 101, the positive electrode sheet, solid electrolyte layer and negative electrode sheet of the battery are stacked by a stacking machine and then pre-pressed. Specifically, it can be a preheating and pressing process to make a certain amount of extrusion contact between the positive electrode sheet, solid electrolyte layer and negative electrode sheet, so as to prevent the subsequent ceramic particles from filling and penetrating into the gaps between the layer interfaces, thus obtaining the all-solid-state battery core, which serves as the precursor of the first battery mentioned above.

[0091] Optionally, step 101 specifically includes: stacking a positive electrode, a solid electrolyte layer, and a negative electrode and pre-pressing them to obtain a first battery precursor including the positive electrode, the solid electrolyte layer, and the negative electrode, wherein the solid electrolyte layer is filled between the positive electrode and the negative electrode. Through preheating and pressing, an all-solid-state battery core including the positive electrode, the solid electrolyte layer, and the negative electrode, wherein the solid electrolyte layer is filled between the positive electrode and the negative electrode, is obtained as the first battery precursor.

[0092] In practical applications, as shown in Figure 4, the stacked electrode core 10 obtained by stacking the positive electrode 11, the solid electrolyte layer 12 and the negative electrode 13 of the battery through the upper hot press head 21 and the lower hot press head 22 of the stacking machine can be used as the precursor of the first battery.

[0093] Step 102: Fill the edges of the first battery precursor with ceramic particles and insulating adhesive to form the second battery precursor.

[0094] In step 102, ceramic particles and insulating adhesive are filled into the edges of the positive and negative electrode sheets in the first battery precursor. This can provide insulation and support for the edges during the isostatic pressing process, effectively preventing the cell edges from collapsing, bending, or short circuits caused by material loss during the isostatic pressing process. It also makes it less likely for thermal expansion to occur during subsequent charging and discharging.

[0095] Optionally, step 102 specifically includes: filling the edges of the first battery precursor with ceramic particles and insulating adhesive to obtain a second battery precursor with a sealing edge at the edges of the positive and negative electrode sheets. By filling the edges of the first battery precursor with ceramic particles and insulating adhesive, a fully solid-state battery core is obtained, comprising an electrode sheet, a solid electrolyte layer, and a negative electrode sheet, with the solid electrolyte layer filling between the positive and negative electrode sheets, and the edges of the positive and negative electrode sheets filled with a sealing edge, serving as the aforementioned second battery precursor.

[0096] Step 103: Encapsulate the second battery precursor to obtain a solid-state battery.

[0097] In step 103, a solid-state battery is obtained by encapsulating and molding the second battery precursor.

[0098] In this embodiment of the invention, after the all-solid-state battery cores are stacked, they are first preheated and pressed using a hot press, then ceramic particles and insulating adhesive are filled at the edges, and then they are encapsulated and molded to obtain an all-solid-state battery with good edge sealing performance and insulation.

[0099] Optionally, in one embodiment, the stacking of the positive electrode, the solid electrolyte layer, and the negative electrode includes:

[0100] The solid electrolyte layer is configured to cover both sides of the negative electrode sheet to form a negative electrode composite sheet;

[0101] The negative electrode composite sheet is stacked with the positive electrode sheet such that the edge of the negative electrode composite sheet extends beyond the positive electrode sheet.

[0102] In this embodiment, a solid electrolyte layer is first set on both sides of the negative electrode sheet to form a negative electrode composite sheet. Then, by using the way that the edge of the negative electrode composite sheet extends beyond the positive electrode sheet, the negative electrode composite sheet and the positive electrode sheet are stacked together, that is, a cantilevered area is formed, so that the negative electrode sheet covers the positive electrode sheet, which can effectively avoid short circuit between the positive and negative electrodes.

[0103] Optionally, in one embodiment, step 102 includes steps 121 to 122:

[0104] Step 121: Fill the edge of the first battery precursor with ceramic particles to form a ceramic layer.

[0105] In step 121, because the first battery precursor has been pre-pressed, there is a strong bonding strength between the positive electrode, the solid electrolyte layer and the negative electrode, so ceramic particles can be filled at the edge of the first battery precursor.

[0106] For example, when a negative electrode composite sheet 120 is formed by pre-forming solid electrolyte layers on both sides of the negative electrode sheet 12, the specific effect of filling ceramic particles at the edge of the first battery precursor to form a ceramic layer 141 is shown in Figure 5.

[0107] Step 122: Cover the ceramic layer with insulating adhesive to form an insulating adhesive layer.

[0108] In step 122, adhesive is applied around the uniformly filled second battery precursor to cover the ceramic layer with an insulating adhesive layer, thus obtaining the aforementioned second battery precursor.

[0109] As an example, the effect after filling ceramic particles to form a ceramic layer 141 and covering it with an insulating adhesive layer 142 is shown in Figure 6.

[0110] In this embodiment, an insulating adhesive layer is used to cover the ceramic layer formed by ceramic particles, thereby sealing and filling the ceramic particles at the edges of the positive and negative electrode sheets, thus avoiding the flow and seepage problems that are prone to occur with liquid filling.

[0111] Optionally, in one specific embodiment, step 121 above includes:

[0112] The ceramic particles are filled into the edge of the first battery precursor by ultrasonic vibration.

[0113] In this specific embodiment, the ceramic particles can be densely filled at the edge of the first battery precursor using an ultrasonic vibration filling method.

[0114] As shown in Figure 7, when ultrasonic vibration fills ceramic particles, the ultrasonic generator, which serves as the vibration source 31, inputs a high-frequency electrical signal to the transducer. The transducer converts the signal into mechanical vibration of the same frequency, driving the vibrating disk 32 in phase. The ceramic particles in the vibrating disk 32 move rapidly, filling the overhang area of ​​the pre-compressed electrode core 20 (the first battery precursor) evenly.

[0115] In practical applications, the filling density at the edge of the electrode core can be controlled by adjusting the frequency of ultrasonic vibration.

[0116] Optionally, in one specific embodiment, the pre-pressing temperature is 80-100°C and the pressure is 10-20 MPa, which enables the positive and negative electrode sheets to be in close contact, making it difficult for the positive and negative electrode sheets to shift or become misaligned, and making it easy to fill the edges with ceramic particles by ultrasonic vibration.

[0117] Optionally, in one specific embodiment, during ultrasonic vibration, the main frequency of the ultrasonic wave is 20-40 kHz, which can densely fill the edges of the positive and negative electrode sheets with ceramic particles and prevent the positive and negative electrode sheets from being dispersed.

[0118] Optionally, in one embodiment, step 103 includes:

[0119] The second battery precursor is encapsulated with an encapsulation film, then isostatically pressed, and finally the encapsulation film is removed.

[0120] In this embodiment, the second battery precursor is vacuum heat-sealed with an encapsulation film and placed in an ultra-high pressure isostatic press for isostatic pressing. After isostatic pressing, the encapsulation film is removed to obtain an electrode core with good edge sealing performance and insulation. Then, it is encapsulated to obtain an all-solid-state battery.

[0121] In the isostatic pressing process, an aluminum-plastic film is used to wrap the electrode core to form an isostatic pressing interface for isostatic pressing molding.

[0122] The aforementioned encapsulation film can be an aluminum-plastic film.

[0123] Among them, the vacuum pressure of vacuum heat sealing is 0 to 100 Pa, which can use the high vacuum to remove the gas inside the package and avoid the easy explosion of the product during the high temperature and high pressure isostatic pressing process; the temperature of isostatic pressing is 80 to 150℃ and the pressure is 400 to 600 MPa, which can effectively shorten the densification degree of the product and shorten the core forming time.

[0124] For example, the electrode core 30 (i.e., the second battery precursor) filled with ceramic particles and insulating adhesive is first vacuum heat-sealed using an aluminum-plastic film 33. Both the long side a and the short side b are sealed with the aluminum-plastic film 33, as shown in Figure 8. Then, an ultra-high pressure temperature isostatic press is used for isostatic pressing. During isostatic pressing, the electrode core 40 sealed with the aluminum-plastic film is placed in the pressure chamber 34 of the ultra-high pressure temperature isostatic press, and pressure is applied using a booster 35, as shown in Figure 9. Then, the aluminum-plastic film on the surface is removed to obtain the above-mentioned shaped electrode core. After further encapsulation, an all-solid-state battery is obtained, as shown in Figure 1.

[0125] In this embodiment of the invention, the overall fabrication process of the solid-state battery is shown in Figure 10.

[0126] As shown in Figure 10, the positive electrode sheet and the negative electrode composite sheet are first stacked in sequence to form a pre-formed electrode core, and then preheated and pressed to form the first battery precursor. Then, ceramic particles are filled into the pits between the positive electrode sheet and the negative electrode sheet in the first battery precursor by means of ultrasonic vibration, and adhesive is applied around the perimeter to form the second battery precursor. Next, the second battery precursor is vacuum heat-sealed with an aluminum-plastic film that matches the size of the second battery precursor. The sealed cell is then placed in an ultra-high pressure temperature isostatic press for isostatic pressing. After the isostatic pressing process is completed and the aluminum-plastic film is removed, a second sealing is performed to obtain the all-solid-state battery electrode core.

[0127] The present invention also proposes an electrical device, wherein the solid-state battery described above is included, and the solid-state battery serves as the power supply for the electrical device.

[0128] The above-described solid-state battery embodiments and electrical device embodiments include the aforementioned polymer electrolyte and achieve the same technical effects. To avoid repetition, they will not be described again here. For relevant details, please refer to the description of the polymer electrolyte embodiments.

[0129] To make the inventive objectives, technical solutions, and beneficial effects of this invention clearer, the invention is further described below with reference to embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0130] The present invention will be described in detail below through embodiments.

[0131] Example 1

[0132] (1) Preparation of positive electrode sheet

[0133] LiNi, the positive electrode active material 0.9 Co 0.05 Mn 0.05 O2, solid electrolyte Li6PS5Cl1, binder HNBR, and conductive agent Super P are mixed evenly in N,N-dimethylformamide at a mass ratio of 80:2:1:1, and then the slurry is applied to the aluminum current collector with a scraper.

[0134] (2) Preparation of negative electrode sheet

[0135] A negative electrode sheet with a length and width 1 mm larger on each side than the positive electrode sheet was prepared by mixing pure Si material, binder PAA-Li-BA-2916-Li, thickener CMC2800, and deionized water in a mass ratio of 96:50:1:138.7.

[0136] (3) Preparation of negative electrode composite sheet

[0137] Solid electrolyte Li6PS5Cl1 and binder HNBR are mixed at a mass ratio of 99:1 and then applied to both sides of the negative electrode sheet to form a negative electrode composite sheet.

[0138] (4) Solid-state battery fabrication

[0139] In an argon-filled glove box, the positive electrode and negative electrode composite sheet are assembled in sequence. Then, they are preheated and pressed at a temperature of 90℃ and a pressure of 15MPa. Next, 20µm alumina ceramic particles are filled into the edges using ultrasonic waves with a main frequency of 30kHz. Then, 20µm thick PET insulating adhesive is applied around the perimeter in the direction perpendicular to the electrode stacking. After vacuum heat sealing with aluminum-plastic film, it is isostatically pressed at a pressure of 500MPa and a temperature of 100℃. Finally, the aluminum-plastic film is removed to produce a solid-state battery.

[0140] Example 2

[0141] The only difference from Example 1 is that in step (4), the pressure of isostatic pressing is adjusted to 400 MPa and the temperature to 80°C.

[0142] Example 3

[0143] The only difference from Example 1 is that in step (4), the pressure of isostatic pressing is adjusted to 600 MPa and the temperature to 150°C.

[0144] Example 4

[0145] The only difference from Example 1 is that in step (4), the pressure of the preheating pressure is adjusted to 10 MPa and the temperature is 80°C.

[0146] Example 5

[0147] The only difference from Example 1 is that in step (4), the pressure of the preheating pressure is adjusted to 20 MPa and the temperature is 100°C.

[0148] Example 6

[0149] The only difference from Example 1 is that in step (4), the main frequency of the ultrasonic wave is adjusted to 20KHz.

[0150] Example 7

[0151] The only difference from Example 1 is that in step (4), the main frequency of the ultrasonic wave is adjusted to 40KHz.

[0152] Example 8

[0153] The only difference from Example 1 is that in step (4), the particle size of the ceramic particles is adjusted to 1 μm.

[0154] Example 9

[0155] The only difference from Example 1 is that in step (4), the particle size of the ceramic particles is adjusted to 50 μm.

[0156] Example 10

[0157] The only difference from Example 1 is that, in step (2), the thickness of the insulating adhesive layer is adjusted to 5 μm.

[0158] Example 11

[0159] The only difference from Example 1 is that, in step (2), the thickness of the insulating adhesive layer is adjusted to 50 μm.

[0160] Example 12

[0161] The only difference from Example 1 is that in step (2), the negative electrode sheet is adjusted to be 0.1 mm larger in both length and width than the positive electrode sheet.

[0162] Example 13

[0163] The only difference from Example 1 is that in step (2), the negative electrode sheet is adjusted to be 10 mm larger in both length and width than the positive electrode sheet.

[0164] Example 14

[0165] The only difference from Example 1 is that in step (4), the particle size of the ceramic particles is adjusted to 10 μm.

[0166] Comparative Example 1

[0167] The difference between Comparative Example 1 and Example 1 is that in step (4), the positive electrode sheet and the negative electrode composite sheet are assembled directly in a glove box filled with argon gas. After vacuum heat sealing with aluminum-plastic film, isostatic pressing is performed under a pressure of 500MPa and a temperature of 100℃. Then the aluminum-plastic film is removed to make a solid-state battery.

[0168] Comparative Example 2

[0169] The difference between Comparative Example 2 and Example 1 is that in step (4), the positive electrode sheet and the negative electrode composite sheet are assembled directly in a glove box filled with argon gas, and PET insulating glue is used as a sealing edge. After vacuum heat sealing with aluminum-plastic film, isostatic pressing is performed under a pressure of 500MPa and a temperature of 100°C. Then the aluminum-plastic film is removed to make a solid-state battery.

[0170] The solid-state batteries prepared in each embodiment and comparative example were subjected to first-cycle capacity testing, first-cycle efficiency testing, and cycle performance testing. The test data are shown in Table 1.

[0171] Test method:

[0172] (1) First discharge specific capacity test: Connect the prepared battery to the charge and discharge test cabinet, charge it to 100% SOC at a rate of 0.1C, and record the charging capacity; let it stand for 5 minutes, then discharge it to 0SOC at a rate of 0.1C, record the discharge capacity and divide it by the battery mass, and record it as the first discharge specific capacity.

[0173] (2) First-cycle efficiency test: Calculate the percentage of discharge capacity to charge capacity in the above process, and record it as the first-cycle efficiency.

[0174] (3) Cyclic performance test: The battery is charged and discharged at a rate of 0.33C until the battery discharge capacity is reduced to 80% of the initial discharge capacity. The number of cycles at that time is recorded as the cycle performance.

[0175] Table 1

[0176]

[0177]

[0178] Based on the above test data, the edges of the positive and negative electrode sheets are filled with a sealing edge formed by ceramic particles and insulating adhesive. The ceramic particles can play a supporting and insulating role during the pressing process, which can improve the yield of electrode core forming. At the same time, the pressed ceramic does not expand due to heat, which can effectively improve the problems of edge collapse, material loss and short circuit in existing solid-state batteries.

[0179] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0180] The present invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. 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 the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A solid-state battery, characterized in that, It includes a positive electrode, a solid electrolyte layer, and a negative electrode. The solid electrolyte layer is filled between the positive electrode and the negative electrode, and the edges of the positive electrode and the negative electrode are filled with sealing edges. The sealing edges are made of ceramic particles and insulating adhesive.

2. The solid-state battery according to claim 1, characterized in that, The ceramic particles have a particle size of 1–50 μm.

3. The solid-state battery according to claim 1, characterized in that, The insulating adhesive is at least one of PET insulating adhesive, polyimide, and polytetrafluoroethylene.

4. The solid-state battery according to claim 1, characterized in that, The sealing edge includes a ceramic layer and an insulating adhesive layer. The ceramic layer fills the edge recesses of the positive electrode and the negative electrode, and the insulating adhesive layer at least covers the ceramic layer.

5. The solid-state battery according to claim 4, characterized in that, The ceramic layer fills the recesses around the first electrode and between the second electrode. The first electrode is the electrode with smaller length and width dimensions between the positive electrode and the negative electrode, and the second electrode is the electrode with larger length and width dimensions between the positive electrode and the negative electrode.

6. The solid-state battery according to claim 5, characterized in that, The compaction density of the ceramic layer is 3 g / m³. 3 ~4g / m 3 .

7. The solid-state battery according to claim 5, characterized in that, The thickness of the insulating adhesive layer in the direction perpendicular to the electrode stacking is 5–50 μm.

8. The solid-state battery according to any one of claims 1 to 7, characterized in that, The negative electrode has a cantilevered region extending beyond the edge of the positive electrode, and the solid electrolyte layer covers the cantilevered region.

9. The solid-state battery according to claim 8, characterized in that, The width of the cantilevered area is 0.2 to 10 mm.

10. A method for preparing a solid-state battery, characterized in that, include: A first battery precursor is obtained by stacking a positive electrode, a solid electrolyte layer, and a negative electrode and pre-pressing them; a second battery precursor is formed by filling the edges of the first battery precursor with ceramic particles and insulating adhesive; and the second battery precursor is encapsulated to obtain the solid-state battery.

11. The preparation method according to claim 10, characterized in that, A first battery precursor is obtained by stacking and pre-pressing a positive electrode, a solid electrolyte layer, and a negative electrode, including: stacking and pre-pressing a positive electrode, a solid electrolyte layer, and a negative electrode to obtain a first battery precursor including the positive electrode, the solid electrolyte layer, and the negative electrode, wherein the solid electrolyte layer is filled between the positive electrode and the negative electrode; and filling the edges of the first battery precursor with ceramic particles and insulating adhesive to form a second battery precursor, including: filling the edges of the first battery precursor with ceramic particles and insulating adhesive to obtain a second battery precursor with a sealed edge at the edges of the positive electrode and the negative electrode.

12. The preparation method according to claim 10 or 11, characterized in that, Filling the edge of the first battery precursor with ceramic particles and insulating adhesive includes: filling the edge of the first battery precursor with ceramic particles to form a ceramic layer; and covering the ceramic layer with insulating adhesive to form an insulating adhesive layer.

13. The preparation method according to claim 12, characterized in that, Filling the edge of the first battery precursor with ceramic particles includes: filling the edge of the first battery precursor with ceramic particles by ultrasonic vibration.

14. The preparation method according to claim 13, characterized in that, The pre-compression temperature is 80–100℃ and the pressure is 10 MPa–20 MPa; and / or the ultrasonic vibration has a main ultrasonic frequency of 20–40 kHz.

15. The preparation method according to claim 10 or 11, characterized in that, Stacking a positive electrode, a solid electrolyte layer, and a negative electrode includes: setting the solid electrolyte layer to cover both sides of the negative electrode to form a negative electrode composite sheet; and stacking the negative electrode composite sheet and the positive electrode sheet such that the edge of the negative electrode composite sheet extends beyond the positive electrode sheet.

16. The preparation method according to claim 10 or 11, characterized in that, Encapsulating the second battery precursor includes: encapsulating the second battery precursor with an encapsulation film, isostatically pressing it, and then removing the encapsulation film.

17. The preparation method according to claim 15, characterized in that, The isostatic pressing temperature is 80–150℃, and the pressure is 400–600MPa.

18. An electrical appliance, characterized in that, Includes solid-state batteries as described in any one of claims 1 to 9, or solid-state batteries prepared by the methods described in claims 10 to 17.

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