Battery pole piece, preparation method thereof and all-solid-state lithium ion battery

Abstract

The invention discloses a battery pole piece, a preparation method thereof and an all-solid-state lithium ion battery. The battery pole piece comprises a current collector and positive electrode slurry coatings coated on two sides of the current collector, and a solid electrolyte membrane which is cured through in-situ printing based on a 3D printing technology is arranged in the middle of the positive electrode slurry coatings. Insulating ceramic adhesive coatings which are cured through in-situ printing based on a 3D printing technology are arranged on the areas, close to the peripheral edge, of the positive electrode slurry coating and the areas, close to the positive electrode slurry coating, of the two sides of the tab. According to the battery pole piece formed through 3D printing, the short-circuit rate of an all-solid-state lithium ion battery can be effectively reduced, and the energy density and the rate capability of the all-solid-state lithium ion battery can be improved; the problem of short circuit or insulation reduction caused by the ultrathin solid electrolyte and burrs on the edge of the pole piece can be prevented, and the consistency, the stability and the safety of the battery are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery pole piece and a preparation method thereof, and an all-solid-state lithium-ion battery. Background Art

[0002] Currently, the electrical performance requirements for traditional liquid lithium-ion batteries are increasingly stringent, especially in terms of energy density. However, increasing the energy density of liquid lithium-ion batteries is becoming increasingly difficult, and as energy density increases, safety performance is also affected. Traditional liquid lithium-ion batteries use organic electrolytes with high ionic conductivity, low boiling points, and flammability. Under extreme operating conditions, they are prone to safety accidents such as fires and explosions caused by electrolyte leakage and decomposition.

[0003] All-solid-state batteries can not only provide higher energy density than liquid lithium-ion batteries, but also fundamentally reduce the many safety risks associated with liquid electrolytes. All-solid-state batteries use solid electrolytes to replace electrolytes and separators. Solid electrolytes can also isolate the positive and negative electrodes from direct contact and build Li + The role of the transmission channel. Compared with electrolytes, solid electrolytes do not volatilize, are difficult to decompose, and are non-flammable, thus greatly improving the safety performance of the battery. The design of solid-state batteries reduces the total weight and volume of the battery, eliminates the separator and electrolyte in traditional liquid lithium-ion batteries, and replaces them with a solid electrolyte layer. The solid electrolyte layer has become the core component of solid-state batteries. The solid electrolyte layer has the characteristics of high ionic conductivity, high safety, high mechanical penetration strength, good flexibility, and the ability to be industrially scaled up.

[0004] The existing preparation method of solid-state batteries is to apply a composite electrolyte slurry on one side of the positive electrode sheet or the negative electrode sheet to form a composite electrolyte layer, and obtain a composite positive electrode sheet or a composite negative electrode sheet after curing. The positive electrode sheet or the composite negative electrode sheet are laminated or wound together by a lamination or winding process, so that the composite electrolyte layer is sandwiched between the positive and negative electrode sheets; rolling or isostatic pressing is used to make the positive and negative electrode sheets and the solid electrolyte contact closely, thus obtaining a solid-state battery.

[0005] Currently, the solid-state battery production process involves solid-state electrolyte transfer, die-cutting, lamination, packaging, and isostatic pressing. Traditional processes rely on physical molds and mechanical forces, making it difficult to achieve high-precision, stress-free processing. This leads to process defects. For example, during electrode fabrication and electrolyte membrane transfer, uneven material distribution leads to edge stress concentration; during die-cutting, mechanical cutting generates burrs, and die wear causes edge deformation; during isostatic pressing, high global pressure is applied, causing fragile edges to easily deform or even collapse.

[0006] The above-mentioned defects in the solid-state battery production process may cause burrs and deformation on the edges of the produced electrodes, or even direct contact between the positive and negative electrodes, causing battery short circuits and even thermal runaway, fires and explosions.

[0007] One of the biggest challenges in the preparation of solid-state batteries is how to make the solid electrolyte as thin as possible while maintaining manufacturing precision. Existing solid-state battery production technology uses modified coating materials and complex manufacturing processes to prepare solid electrolyte films that can be used in traditional battery manufacturing processes. This method is too expensive and is not conducive to the industrialization of all-solid-state batteries. Moreover, in this traditional "sandwich" structure of all-solid-state batteries, the layers cannot be tightly bonded, resulting in an increase in the internal impedance of the battery, which in turn limits the optimization and improvement of all-solid-state battery performance. Summary of the Invention

[0008] The purpose of the present invention is to overcome the deficiencies and defects of the prior art and to provide a battery pole piece and a preparation method thereof and an all-solid-state lithium-ion battery.

[0009] One purpose of the present invention is to provide a battery electrode, comprising a current collector and a positive electrode slurry coating applied on both sides of the current collector, wherein a solid electrolyte membrane is provided in the middle part of the positive electrode slurry coating and is cured by in-situ printing based on 3D printing technology, and an insulating ceramic glue coating is provided in the area near the outer edge of the positive electrode slurry coating and near the positive electrode slurry coating on both sides of the tab and is cured by in-situ printing based on 3D printing technology.

[0010] Preferably, the solid electrolyte membrane is sealed and surrounded on the outer peripheral side by an insulating ceramic glue coating near the outer peripheral edge of the positive electrode slurry coating.

[0011] Preferably, the insulating ceramic glue coating in the area near the positive electrode slurry coating on both sides of the tab is connected to the solid electrolyte membrane through the insulating ceramic glue coating near the outer peripheral edge of the positive electrode slurry coating.

[0012] Preferably, the thickness of the solid electrolyte membrane on one side is greater than the thickness of the positive electrode slurry coating on the same side.

[0013] Preferably, the thickness of the solid electrolyte membrane on one side is 5.0 μm-25.0 μm, the thickness of the solid electrolyte membrane on both sides is 10.0 μm-50.0 μm, and the total surface density of the solid electrolyte membrane is 2.0-10.0 mg / cm 2 .

[0014] Preferably, the distance between the edge of the solid electrolyte membrane on one side and the edge of the positive electrode slurry coating is 0.5-4 mm.

[0015] Preferably, the width of the insulating ceramic glue coating near the outer peripheral edge of the positive electrode slurry coating is 0.5-4 mm.

[0016] Preferably, the width of the insulating ceramic glue coating in the area near the positive electrode slurry coating on both sides of the tab is 1-4 mm.

[0017] A second object of the present invention is to provide a method for preparing a battery electrode sheet, which comprises the following steps:

[0018] The prepared positive electrode slurry is coated on the current collector according to the electrode design parameters, and the positive electrode sheet is obtained after drying, rolling and cutting;

[0019] The prepared solid electrolyte membrane slurry for 3D printing is in-situ printed onto the middle area of ​​the positive electrode slurry coating on the positive electrode sheet by a 3D printing device to prepare a solid electrolyte membrane of target thickness;

[0020] The prepared insulating ceramic adhesive coating for 3D printing is in-situ printed around the edge of the solid electrolyte membrane and the area near the positive electrode slurry coating on both sides of the tab using a 3D printing device to prepare the insulating ceramic adhesive coating; the electrode is punched to obtain the battery electrode.

[0021] The third object of the present invention is to provide an all-solid-state lithium-ion battery comprising the battery pole piece.

[0022] The 3D-printed battery electrode of the present invention has the advantages of high consistency, strong stability, and ultra-thinness in the solid electrolyte membrane obtained by 3D printing technology. It can effectively reduce the short-circuit rate of the all-solid-state lithium-ion battery, improve the consistency, stability and safety of the battery, and improve the energy density and rate performance of the all-solid-state lithium-ion battery. At the same time, the ceramic glue layer with insulating effect on the edges is obtained by 3D printing technology, which can prevent the problem of short circuit or insulation degradation caused by ultra-thin solid electrolyte and burrs on the edges of the electrode, thereby improving the safety of the battery, thereby providing an all-solid-state lithium-ion battery that is not prone to short circuit risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a planar schematic diagram of the battery electrode of the present invention.

[0024] Figure 2 It is a cross-sectional schematic diagram of the battery electrode of the present invention.

[0025] Figure 3 It is a flow chart of the preparation method of the all-solid-state lithium-ion battery of the present invention.

[0026] Reference numerals:

[0027] 1-current collector (aluminum foil), 2-insulating ceramic glue coating, 3-positive electrode slurry coating, 4-solid electrolyte membrane. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] In an exemplary embodiment of the present application, a battery electrode is provided, which is obtained by in-situ printing and curing a solid electrolyte membrane in the middle part of the positive electrode slurry coating through 3D printing technology, and in-situ printing and curing an insulating ceramic glue layer around the edges of the positive electrode slurry coating and the position of the electrode tab through 3D printing technology.

[0030] See Figure 1 、 Figure 2 As shown, in an exemplary embodiment of the present application, a battery electrode is provided, comprising a current collector 1, a positive electrode slurry coating 3 coated on both sides of the current collector, a solid electrolyte membrane 4 in the middle part of the positive electrode slurry coating that is in-situ printed and cured based on 3D printing technology, and an insulating ceramic glue coating 2 that is in-situ printed and cured based on 3D printing technology near the outer peripheral edge of the positive electrode slurry coating and near the positive electrode slurry coating on both sides of the tab.

[0031] 3D printing is a cutting-edge manufacturing technology that builds three-dimensional objects by stacking and accumulating raw materials layer by layer based on digital model files. It offers advantages such as arbitrary shaping, rapid prototyping, and high production efficiency. The battery pole pieces in the embodiments of this application utilize 3D printing technology, which offers the advantage of precisely manufacturing complex battery structures. This allows for high-precision printing of complex electrode and electrolyte layers while ensuring high consistency and stability across all layers within the battery.

[0032] In an embodiment of the present application, the solid electrolyte membrane is sealed and surrounded on the outer side by an insulating ceramic glue coating near the outer peripheral edge of the positive electrode slurry coating, and the insulating ceramic glue coating in the area near the positive electrode slurry coating on both sides of the tab is connected to the insulating ceramic glue coating near the outer peripheral edge of the positive electrode slurry coating on the solid electrolyte membrane.

[0033] In the embodiment of the present application, the thickness of the solid electrolyte membrane on one side is greater than the thickness of the positive electrode slurry coating on the same side. In a preferred embodiment, the thickness of the solid electrolyte membrane on one side is in the range of 5.0μm-25.0μm, which is determined according to needs. The specific thickness can be selected within this range. According to the experience of battery preparation, it is generally implemented within this range. The thickness of the solid electrolyte membrane on both sides can be the same or different, preferably the same thickness. The thickness of the solid electrolyte membrane on both sides is 10.0μm-50.0μm, and the total surface density of the solid electrolyte membrane is 2.0-10.0mg / cm 2 Within the range, it is determined according to the performance requirements of the battery to meet the performance requirements of the battery.

[0034] In the embodiment of the present application, the distance between the edge of the solid electrolyte membrane on one side and the edge of the positive electrode slurry coating is within the range of 0.5-4 mm, which is determined as needed. If this distance is too narrow, it is not conducive to the performance of its insulation performance. If it is too wide, it will occupy space for the solid electrolyte membrane and affect the performance of the battery.

[0035] In the embodiments of the present application, the width of the insulating ceramic adhesive coating near the outer edge of the positive electrode slurry coating is within a range of 0.5-4 mm, determined as needed. If this width is too narrow, it will not be conducive to the performance of its insulation performance. If it is too wide, it will occupy space in the solid electrolyte membrane and affect battery performance. The width can be selected within this range as needed.

[0036] In the embodiment of the present application, the width of the insulating ceramic adhesive coating near the positive electrode slurry coating on both sides of the tab is within a range of 1-4 mm, determined as needed. If the width is too narrow, it will not be conducive to the performance of its insulation performance, while if it is too wide, it will occupy the tab area. The specific width can be selected within this range according to needs.

[0037] A second object of the present invention is to provide a method for preparing a battery electrode sheet, which comprises the following steps:

[0038] The prepared positive electrode slurry is coated on the current collector according to the electrode design parameters, and the positive electrode sheet is obtained after drying, rolling and cutting;

[0039] The prepared solid electrolyte membrane slurry for 3D printing is in-situ printed onto the middle area of ​​the positive electrode slurry coating on the positive electrode sheet by a 3D printing device to prepare a solid electrolyte membrane of target thickness;

[0040] The prepared insulating ceramic adhesive coating for 3D printing is in-situ printed around the edge of the solid electrolyte membrane and the area near the positive electrode slurry coating on both sides of the tab using a 3D printing device to prepare the insulating ceramic adhesive coating; the electrode is punched to obtain the battery electrode.

[0041] Prepare the positive electrode slurry and apply it to the aluminum foil, then use 3D printing to in-situ cure the prepared solid electrolyte slurry to the middle part of the positive electrode coating, and then use 3D printing to in-situ cure the prepared ceramic glue to the edges around the positive electrode coating and the tab area to obtain a composite positive electrode sheet. The structural characteristics of the composite positive electrode sheet are: from the inside to the outside, aluminum foil, positive electrode coating, solid electrolyte coating, and ceramic glue coating around the edges of the positive electrode coating and the tab area.

[0042] Specifically, the steps for preparing the battery electrode, i.e., the positive electrode, are as follows:

[0043] Prepare the positive electrode slurry, and then evenly apply it to the current collector (aluminum foil) by coating, and obtain the positive electrode sheet after rolling and cutting; prepare the solid electrolyte slurry, and use 3D printing to in-situ print and solidify the solid electrolyte slurry on the middle part of the positive electrode coating of the positive electrode sheet, and after drying and rolling, obtain a composite positive electrode sheet substrate with a solid electrolyte membrane on the surface; prepare ceramic glue, and then use 3D printing to in-situ print and solidify the ceramic glue on the edges of the positive electrode sheet substrate and the tab area, and obtain a composite positive electrode sheet after drying.

[0044] In the embodiment of the present application, the positive electrode coating is composed of a positive electrode active material, a solid electrolyte, a conductive agent and a binder, and the solid electrolyte membrane is composed of a solid electrolyte, a lithium salt and a binder. The combination of the two has high compatibility and good conductivity and safety performance; the ceramic glue coating around the edges of the positive electrode sheet and the tab area can significantly reduce the short circuit rate of the electrode group and improve the safety performance of the battery; the all-solid-state lithium-ion battery assembled by assembling the composite positive electrode sheet and the graphite negative electrode sheet and other related materials prepared by this scheme has excellent rate performance and safety performance.

[0045] A third object of the present invention is to provide an all-solid-state lithium-ion battery comprising the battery pole piece. The all-solid-state lithium-ion battery, due to comprising the battery pole piece, has excellent rate performance and safety performance.

[0046] Next, the preparation process of the battery pole piece including the embodiment of the present application is described as an example, and the preparation process of the all-solid-state lithium-ion battery including the battery pole piece is described. Figure 3 As shown:

[0047] Step 1: Prepare the solid-state battery positive electrode slurry and then prepare the positive electrode sheet.

[0048] First, a positive electrode slurry is prepared. The positive electrode slurry includes a positive electrode active material, a first solid electrolyte, a conductive agent, and a first binder. Using NMP as a solvent, the components of the positive electrode slurry are added in a specific order to form a slurry. The prepared positive electrode slurry is then coated onto a current collector according to the electrode sheet design parameters. After drying, rolling, and slitting, the positive electrode sheet is obtained.

[0049] The mass ratio of the components in the positive electrode slurry is: positive electrode active material: first solid electrolyte: conductive agent: first binder = A: B: C: (1-ABC), where 50% ≤ A ≤ 90%, 10% < B ≤ 30%, 0.1% < C ≤ 5%. The positive electrode active material is LiNi x Co y Mn 1-x-y O2、LiNi x Co y Al 1-x-yO2, LiFePO4, LiMn x Fe 1-x PO4, LiCoO2; the first solid electrolyte is an oxide electrolyte (LATP, LLZTO, LLZO, LLTO), a sulfide electrolyte (Li (6-x) PS (5-x) M (1+x) or yLi2S·(1-y)P2S5, Li 10 GeP2S 12 At least one of the following, 0≤x≤0.6, 0.2≤y≤0.8, M=Cl, Br, I;), a combination of one or more of the halide electrolytes; the conductive agent is a combination of one or more of carbon black, acetylene black, graphene, carbon nanotubes, and mesophase carbon microspheres; the first binder is a combination of one or more of polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyethylene oxide, and polyacrylonitrile.

[0050] The positive electrode coating layer density is 20-60 mg / cm 2 The preferred surface density is 30-50 mg / cm 2 The overall thickness of the positive electrode sheet after rolling is 70-200 μm.

[0051] Step 2: Prepare a solid electrolyte slurry for 3D printing, which includes a second solid electrolyte, a lithium salt, and a second binder. The solvent and each component are added in a certain order and process to prepare the slurry, thereby obtaining the solid electrolyte slurry.

[0052] The mass ratio of the components of the solid electrolyte slurry is: second solid electrolyte: lithium salt: second binder = a: b: 1-ab, wherein 70%≤a≤95%, 0%≤b≤20%.

[0053] The second solid electrolyte is an oxide electrolyte (LATP, LLZTO, LLZO, LLTO), a sulfide electrolyte (Li (6-x) PS (5-x) M (1+x) or yLi2S·(1-y)P2S5, Li 10 GeP2S 12At least one of 0≤x≤0.6, 0.2≤y≤0.8, M=Cl, Br, I;), a combination of one or more of the halide electrolytes; the second binder is a combination of one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyacrylonitrile (PAN), sodium carboxymethyl cellulose (CMC-Na) and styrene-butadiene rubber (SBR); the lithium salt is one of lithium hexafluorophosphate (LiPF6), lithium bistrifluoromethylsulfonyl imide (LiTFSI), lithium bisfluorosulfonyl imide (LiFSI), lithium perchlorate (LiClO4), lithium bis(oxalato)borate (LiBOB) and the like.

[0054] The solvent is one or more of NMP, dodecane, butyl butyrate, and xylene.

[0055] Step 3: Prepare solid electrolyte membranes of different thicknesses by controlling the accuracy and speed of 3D printing equipment.

[0056] The solid electrolyte slurry obtained in the second step is in-situ printed onto the middle part of the positive electrode sheet obtained in the first step, and after drying and rolling, a solid electrolyte membrane is formed to obtain a composite positive electrode sheet matrix.

[0057] The fourth step is to prepare ceramic glue and print it in situ on the edge of the positive electrode coating of the composite positive electrode substrate and the area around the ear by 3D printing technology. After the electrode is punched, the composite positive electrode is obtained. Figure 1 、 Figure 3 shown.

[0058] Step 5: Prepare the negative electrode sheet, stack it with the composite positive electrode sheet, weld it, and package it, then perform isostatic pressing to assemble it to obtain a solid-state battery.

[0059] Wherein, the negative electrode sheet is at least one of graphite, silicon, lithium metal or lithium alloy.

[0060] Example 1:

[0061] The positive electrode active material lithium nickel cobalt manganese oxide (LiNi 0.9 Co 0.05 Mn 0.05 O2), solid electrolyte, conductive agent, binder in the mass ratio of 82.0%: 15.0%: 1.0%: 2.0%, and homogenized with NMP solvent to obtain positive electrode slurry A, which was evenly coated on 12μm thick aluminum foil, dried at 120℃, rolled and cut to obtain positive electrode sheets; the coating amount of the positive electrode sheet was 40.0mg / cm 2The thickness of the electrode sheet after rolling is 130μm. The solid electrolyte, lithium salt and binder are prepared in a mass ratio of 85.0%:13.5%:1.5% with NMP as solvent to prepare a solid electrolyte slurry. Then, the solid electrolyte slurry is in-situ printed and solidified into the middle part of the active material layer of the positive electrode sheet using 3D printing technology. After drying and rolling, a solid electrolyte membrane is obtained, and then a composite positive electrode sheet matrix is ​​obtained; the total thickness of the solid electrolyte membrane on both sides is 40.0μm and the surface density is 6.0mg / cm 2 , with its edge 2.0 mm from the edge of the positive electrode coating. A ceramic adhesive is prepared and in-situ printed onto the edges of the composite positive electrode substrate and near the tab using 3D printing technology. After drying, the composite positive electrode sheet is obtained. The ceramic adhesive width around the edge of the electrode sheet is 2.0 mm, and the width of the ceramic adhesive around the tab is 2.0 mm. A graphite negative electrode sheet is prepared and assembled with the composite positive electrode sheet and other materials to obtain an all-solid-state lithium-ion battery.

[0062] Example 2:

[0063] The positive electrode active material lithium nickel cobalt manganese oxide (LiNi 0.9 Co 0.05 Mn 0.05 O2), solid electrolyte, conductive agent, binder in the mass ratio of 77.0%: 20.0%: 1.0%: 2.0%, and homogenized with NMP solvent to obtain positive electrode slurry A, which was evenly coated on 12μm thick aluminum foil, dried at 120℃, rolled and cut to obtain positive electrode sheets; the coating amount of the positive electrode sheet was 42.6mg / cm 2 The thickness of the electrode sheet after rolling is 137μm. The solid electrolyte, lithium salt and binder are prepared in a mass ratio of 80.0%:18.0%:2.0% with NMP as solvent to prepare a solid electrolyte slurry. Then, the solid electrolyte slurry is in-situ printed and solidified into the middle part of the active material layer of the positive electrode sheet using 3D printing technology. After drying and rolling, a solid electrolyte membrane is obtained, and then a composite positive electrode sheet matrix is ​​obtained. The total thickness of the solid electrolyte membrane on both sides is 20.0μm and the surface density is 4.0mg / cm 2 , with its edge 1.5mm from the edge of the positive electrode coating. A ceramic adhesive is prepared and in-situ printed onto the edges of the composite positive electrode substrate and near the tab using 3D printing technology. After drying, the composite positive electrode sheet is obtained. The ceramic adhesive width around the edge of the electrode sheet is 1.5mm, and the width of the ceramic adhesive around the tab is 3.0mm. A graphite negative electrode sheet is prepared and assembled with the composite positive electrode sheet and other materials to obtain an all-solid-state lithium-ion battery.

[0064] Example 3:

[0065] The positive electrode active material lithium nickel cobalt manganese oxide (LiNi 0.9 Co 0.05 Mn0.05 O2), solid electrolyte, conductive agent, binder in the mass ratio of 85.0%: 12.0%: 1.0%: 2.0%, and homogenized with NMP solvent to obtain positive electrode slurry A, which was evenly coated on 12μm thick aluminum foil, dried at 120℃, rolled and cut to obtain positive electrode sheets; the coating amount of the positive electrode sheet was 38.6mg / cm 2 The thickness of the electrode sheet after rolling is 125μm. The solid electrolyte, lithium salt and binder are prepared in a mass ratio of 78.0%:20.0%:2.0% with NMP as solvent to prepare a solid electrolyte slurry. Then, the solid electrolyte slurry is in-situ printed and solidified into the middle part of the active material layer of the positive electrode sheet using 3D printing technology. After drying and rolling, a solid electrolyte membrane is obtained, and then a composite positive electrode sheet matrix is ​​obtained; the solid electrolyte membrane thickness is 28.0μm and the surface density is 5.6mg / cm 2 , with its edge 2.5mm from the edge of the positive electrode coating. A ceramic adhesive is prepared and in-situ printed onto the edges of the composite positive electrode substrate and near the tab using 3D printing technology. After drying, the composite positive electrode sheet is obtained. The ceramic adhesive width around the edge of the electrode sheet is 2.5mm, and the width of the ceramic adhesive around the tab is 3.0mm. A graphite negative electrode sheet is prepared and assembled with the composite positive electrode sheet and other materials to obtain an all-solid-state lithium-ion battery.

[0066] Example 4:

[0067] The positive electrode active material lithium nickel cobalt manganese oxide (LiNi 0.9 Co 0.05 Mn 0.05 O2), solid electrolyte, conductive agent, and binder are mixed in a mass ratio of 88.0%: 10.0%: 1.0%: 1.0%, and slurried with NMP solvent to obtain positive electrode slurry A, which is evenly coated on a 12μm thick aluminum foil, dried at 120°C, and rolled and cut to obtain a positive electrode sheet; the coating amount of the positive electrode sheet is 37.3mg / cm 2 The thickness of the electrode sheet after rolling is 122μm. The solid electrolyte, lithium salt and binder are prepared in a mass ratio of 75.0%:20.0%:5.0% with NMP as solvent to prepare a solid electrolyte slurry. Then, the solid electrolyte slurry is in-situ printed and solidified into the middle part of the active material layer of the positive electrode sheet using 3D printing technology. After drying and rolling, a solid electrolyte membrane is obtained, and then a composite positive electrode sheet matrix is ​​obtained; the solid electrolyte membrane has a thickness of 10.0μm and a surface density of 2.0mg / cm 2, with its edge 4.0 mm from the edge of the positive electrode coating. A ceramic adhesive is prepared and in-situ printed onto the edges of the composite positive electrode substrate and near the tab using 3D printing technology. After drying, the composite positive electrode sheet is obtained. The ceramic adhesive width around the edge of the electrode sheet is 4.0 mm, and the width of the ceramic adhesive around the tab is 2.0 mm. A graphite negative electrode sheet is prepared and assembled with the composite positive electrode sheet and other materials to obtain an all-solid-state lithium-ion battery.

[0068] Example 5:

[0069] The positive electrode active material lithium nickel cobalt manganese oxide (LiNi 0.9 Co 0.05 Mn 0.05 O2), solid electrolyte, conductive agent, binder in the mass ratio of 80.0%: 15.0%: 3.0%: 2.0%, and homogenized with NMP solvent to obtain positive electrode slurry A, which was evenly coated on 12μm thick aluminum foil, dried at 120℃, rolled and cut to obtain positive electrode sheets; the coating amount of the positive electrode sheet was 41.0mg / cm 2 The thickness of the electrode sheet after rolling is 133μm. The solid electrolyte, lithium salt and binder are prepared in a mass ratio of 80.0%:18.0%:2.0% with NMP as solvent to prepare a solid electrolyte slurry. Then, the solid electrolyte slurry is in-situ printed and solidified into the middle part of the active material layer of the positive electrode sheet using 3D printing technology. After drying and rolling, a solid electrolyte membrane is obtained, and then a composite positive electrode sheet matrix is ​​obtained; the solid electrolyte membrane thickness is 30.0μm and the surface density is 6.0mg / cm 2 , with its edge 3.0 mm from the edge of the positive electrode coating. A ceramic adhesive is prepared and in-situ printed onto the edges of the composite positive electrode substrate and near the tab using 3D printing technology. After drying, the composite positive electrode sheet is obtained. The ceramic adhesive width around the edge of the electrode sheet is 3.0 mm, and the width of the ceramic adhesive around the tab is 1.0 mm. A graphite negative electrode sheet is prepared and assembled with the composite positive electrode sheet and other materials to obtain an all-solid-state lithium-ion battery.

[0070] Example 6:

[0071] The positive electrode active material lithium nickel cobalt manganese oxide (LiNi 0.9 Co 0.05 Mn 0.05 O2), solid electrolyte, conductive agent, and binder in a mass ratio of 62.0%: 30.0%: 5.0%: 3.0%, and homogenized with NMP solvent to obtain positive electrode slurry A, which was evenly coated on a 12μm thick aluminum foil, dried at 120°C, rolled, and cut to obtain a positive electrode sheet; the coating amount of the positive electrode sheet was 52.9mg / cm 2The thickness of the electrode sheet after rolling is 168μm. The solid electrolyte, lithium salt and binder are prepared in a mass ratio of 95.0%:3.0%:2.0% with NMP as solvent to prepare a solid electrolyte slurry. Then, the solid electrolyte slurry is in-situ printed and solidified into the middle part of the active material layer of the positive electrode sheet using 3D printing technology. After drying and rolling, a solid electrolyte membrane is obtained, and then a composite positive electrode sheet matrix is ​​obtained; the solid electrolyte membrane has a thickness of 50.0μm and a surface density of 10.0mg / cm 2 , with its edge 0.5mm from the edge of the positive electrode coating. A ceramic adhesive is prepared and in-situ printed onto the edges of the composite positive electrode substrate and near the tab using 3D printing technology. After drying, the composite positive electrode sheet is obtained. The ceramic adhesive width around the edge of the electrode sheet is 0.5mm, and the width of the ceramic adhesive around the tab is 4.0mm. A graphite negative electrode sheet is prepared and assembled with the composite positive electrode sheet and other materials to obtain an all-solid-state lithium-ion battery.

[0072] Comparative Example 1:

[0073] The positive electrode active material lithium nickel cobalt manganese oxide (LiNi 0.9 Co 0.05 Mn 0.05 O2), solid electrolyte, conductive agent, binder in the mass ratio of 82.0%: 15.0%: 1.0%: 2.0%, and homogenized with NMP solvent to obtain positive electrode slurry A, which was evenly coated on 12μm thick aluminum foil, dried at 120℃, and rolled to obtain positive electrode sheet; the coating amount of positive electrode sheet was 40.0mg / cm 2 The thickness of the electrode sheet after rolling is 130μm. The solid electrolyte, lithium salt, and binder are prepared in a mass ratio of 85.0%:13.5%:1.5% using NMP as the solvent to prepare a solid electrolyte slurry. The solid electrolyte slurry is then applied to the active material area of ​​the positive electrode sheet, and the solid electrolyte slurry fully covers the active material area of ​​the positive electrode sheet. After drying, rolling, and cutting, a composite positive electrode sheet with a solid electrolyte layer on the surface is obtained; the solid electrolyte layer is 60.0μm thick. A graphite negative electrode sheet is prepared and assembled with the composite positive electrode sheet and other materials to obtain an all-solid-state lithium-ion battery.

[0074] Comparative Example 2:

[0075] The positive electrode active material lithium nickel cobalt manganese oxide (LiNi 0.9 Co 0.05 Mn 0.05 O2), solid electrolyte, conductive agent, binder in the mass ratio of 82.0%: 15.0%: 1.0%: 2.0%, and homogenized with NMP solvent to obtain positive electrode slurry A, which was evenly coated on 12μm thick aluminum foil, dried at 120℃, rolled and cut to obtain positive electrode sheets; the coating amount of the positive electrode sheet was 40.0mg / cm2 The thickness of the electrode sheet after rolling is 130μm. The solid electrolyte, lithium salt and binder are prepared in a mass ratio of 85.0%:13.5%:1.5% with NMP as solvent to prepare a solid electrolyte slurry. Then, the solid electrolyte slurry is in-situ printed and solidified into the middle part of the active material layer of the positive electrode sheet using 3D printing technology. After drying and rolling, a solid electrolyte membrane is obtained, and then a composite positive electrode sheet matrix is ​​obtained; the total thickness of the solid electrolyte membrane on both sides is 30.0μm and the surface density is 6.0mg / cm 2 , prepare a graphite negative electrode sheet, and assemble it with other materials such as a composite positive electrode sheet to obtain an all-solid-state lithium-ion battery.

[0076] The experimental results show that the performance of Example 1, Example 2, Example 3 and Comparative Example 1 and Comparative Example 2 are as follows:

[0077] Table 1 Battery performance test results

[0078] plan Short circuit rate Energy density (Wh / kg) Rate performance 1C / 0.2C capacity retention rate Example 1 30％ 328 83.3％ Example 2 40％ 327 90.6％ Example 3 30％ 325 86.1％ Comparative Example 1 73％ 318 76.8％ Comparative Example 2 75％ 320 82.6％

[0079] The above test results indicate that all-solid-state battery electrode assembly short-circuit rate and safety performance are significantly superior to those of liquid lithium-ion batteries. All-solid-state lithium-ion batteries fabricated from composite electrode sheets prepared using 3D printing technology exhibit significantly superior electrode assembly short-circuit rate and rate performance compared to all-solid-state lithium-ion batteries fabricated from composite cathode sheets prepared using coating technology. In Examples 1-3, the battery rate performance is correlated with the thickness of the solid-state electrolyte membrane. A thicker solid-state electrolyte membrane results in a lower 1C / 0.2C capacity retention rate, and a thicker solid-state electrolyte membrane is detrimental to battery rate performance.

[0080] From the above description, it can be seen that 3D printing technology can produce the required complex structures at low cost, be environmentally friendly, and be easy to operate. It can also precisely control the shape and thickness of the solid electrolyte membrane. The solid electrolyte membrane obtained by 3D printing has a high stability, good consistency, and adjustable membrane thickness, which can produce solid-state batteries with high energy density and excellent rate performance. At the same time, the ceramic glue around the edges of the electrode has an insulating effect, which can produce a solid-state battery with low short-circuit rate and high safety performance, reducing the battery's self-discharge.

[0081] The basic principles, main features and advantages of the present invention are shown and described above. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention.

[0082] The embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and all changes that come within the meaning and range of equivalents of the claims are therefore intended to be embraced therein.

[0083] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A battery pole piece, characterized in that: It includes a current collector and a positive electrode slurry coating applied on both sides of the current collector. In the middle part of the positive electrode slurry coating, there is a solid electrolyte membrane that is in-situ printed and cured based on 3D printing technology. In the area near the outer edge of the positive electrode slurry coating and near the positive electrode slurry coating on both sides of the tab, there is an insulating ceramic glue coating that is in-situ printed and cured based on 3D printing technology.

2. The battery electrode according to claim 1, characterized in that: The solid electrolyte membrane is sealed and surrounded on the outer peripheral side by an insulating ceramic glue coating near the outer peripheral edge of the positive electrode slurry coating.

3. The battery electrode according to claim 1, characterized in that: The insulating ceramic glue coating in the area near the positive electrode slurry coating on both sides of the tab is connected to the solid electrolyte membrane through the insulating ceramic glue coating near the outer peripheral edge of the positive electrode slurry coating.

4. The battery electrode according to claim 1, characterized in that: The thickness of the solid electrolyte membrane on one side is greater than the thickness of the positive electrode slurry coating on the same side.

5. The battery electrode according to claim 1, characterized in that: The thickness of the solid electrolyte membrane on one side is 5.0 μm-25.0 μm, the thickness of the solid electrolyte membrane on both sides is 10.0 μm-50.0 μm, and the total surface density of the solid electrolyte membrane is 2.0-10.0 mg / cm 2 .

6. The battery electrode according to claim 1, characterized in that: The distance between the edge of the solid electrolyte membrane on one side and the edge of the positive electrode slurry coating is 0.5-4 mm.

7. The battery electrode according to claim 1, characterized in that: The width of the insulating ceramic glue coating near the outer peripheral edge of the positive electrode slurry coating is 0.5-4 mm.

8. The battery electrode according to claim 1, characterized in that: The width of the insulating ceramic glue coating in the area near the positive electrode slurry coating on both sides of the tab is 1-4 mm.

9. A method for preparing a battery pole piece, characterized in that: The preparation method for the battery electrode according to any one of claims 1 to 8 comprises the following steps: The prepared positive electrode slurry is coated on the current collector according to the electrode design parameters, and the positive electrode sheet is obtained after drying, rolling and cutting; The prepared solid electrolyte slurry for 3D printing is in-situ printed onto the middle area of ​​the positive electrode slurry coating on the positive electrode sheet by a 3D printing device to prepare a solid electrolyte membrane of target thickness; The prepared insulating ceramic glue coating for 3D printing is in-situ printed around the edge of the solid electrolyte membrane and the area near the positive electrode slurry coating on both sides of the tab by a 3D printing device to prepare the insulating ceramic glue coating; the electrode is punched to obtain the battery electrode.

10. An all-solid-state lithium-ion battery, characterized in that: The invention comprises the battery electrode according to any one of claims 1 to 8.

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