CN115763824A

CN115763824A - Solid-state lithium ion battery pole piece, preparation method thereof and solid-state lithium ion battery

Info

Publication number: CN115763824A
Application number: CN202211423168.4A
Authority: CN
Inventors: 赵高科; 魏潇博; 梁士轩; 刘张波; 赵嫣然
Original assignee: China Automotive Innovation Corp
Current assignee: China Automotive Innovation Corp
Priority date: 2022-11-07
Filing date: 2022-11-07
Publication date: 2023-03-07

Abstract

The invention provides a solid-state lithium ion battery pole piece, a preparation method thereof and a solid-state lithium ion battery, wherein the solid-state lithium ion battery pole piece comprises a current collector and an electrode layer arranged on at least one side surface of the current collector, the electrode layer is provided with a solid electrolyte layer in a surface lamination mode on one side far away from the current collector, edge sealing layers are arranged on the periphery of the electrode layer and the periphery of the solid electrolyte layer, one side surface of each edge sealing layer is attached to the current collector, and each edge sealing layer comprises a first solid electrolyte. The fixing device can fix the positive and negative pole pieces, prevent the pole pieces from deforming under high pressure to cause the edge contact of the positive and negative poles, avoid the short circuit defect in the preparation process of the battery, greatly improve the yield in the production process of the solid-state lithium ion battery, inhibit the expansion of each part of the solid-state lithium ion battery in the charging and discharging process, and enable the battery to have higher structural stability, thereby effectively improving the cycle performance of the battery.

Description

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

Technical Field

The invention belongs to the field of solid lithium ion batteries, and relates to a solid lithium ion battery pole piece, a preparation method thereof and a solid lithium ion battery.

Background

With continuous technological innovation in the field of downstream application, people put forward higher requirements on the lithium battery industry, and the lithium battery technology develops towards higher specific energy and safety. From the lithium electricity technical development route, solid-state lithium ion battery will be the must way of lithium electricity technical development, but solid-state battery needs great pressure to carry out the compaction in the preparation process, the pole piece is out of shape easily in this in-process, and because the battery inner structure is negative pole area is greater than anodal area usually, the area binding power or the pressure of the negative pole of excessive and electrolyte membrane is less than the part of compounding with the positive pole, consequently excessive area can appear falling the material powderization phenomenon because of shearing force and charge-discharge process expansion and contraction, thereby lead to the pole piece to appear the fracture, little short circuit scheduling problem, the cycling performance of solid-state lithium ion battery has been influenced.

For example, patent CN110828778A discloses a sandwich structure prelithiation negative electrode, which coats electrolyte slurry on the surface of a pole piece, and then stacks the coated composite pole piece, the negative electrode prepared by the technical scheme of the patent has the problems of positive and negative electrode contact caused by edge material drop and internal extension after high pressure, thereby causing abnormal short circuit of the battery; meanwhile, the battery of the patent has the advantages that the expansion change is generated in the battery during charging and discharging, the edge of the battery is not provided with binding parts, so that the change of an internal structure is caused, the cycle performance of the battery is poor, and the performance of the battery is greatly influenced. Further, as shown in patent CN112786840B, it discloses a positive plate for a solid-state battery, and its preparation method and application, the preparation method of the positive plate is: (1) Coating the first slurry on a current collector, drying, rolling, and forming a first active layer on the current collector to obtain a first precursor; (2) Coating the second slurry on the first active layer of the first precursor, drying and rolling to obtain a second active layer, and carrying out warm isostatic pressing treatment to obtain the positive plate for the solid-state battery; although the mechanical strength of the pole pieces is improved by rolling in sequence in a subsection manner, the preparation method still cannot effectively solve the problems of offset short circuit of the positive pole piece and the negative pole piece and expansion of the battery during assembly, and the cycle performance and the safety performance of the battery are influenced.

In summary, the electrode plate which can prevent the electrode plate from deforming under pressure, prevent the edges of the positive and negative electrode plates from contacting short circuit and inhibit the expansion of each part in the charging and discharging process of the battery is provided, and has important significance for the research and development of the solid-state lithium ion battery.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a solid lithium ion battery pole piece, a preparation method thereof and a solid lithium ion battery. According to the invention, the edge sealing layers containing the solid electrolyte are arranged around the electrode layer and the solid electrolyte layer, so that the positive and negative pole pieces can be fixed, the pole pieces are prevented from deforming under high pressure to cause edge contact of the positive and negative poles, the short circuit defect in the battery preparation process is avoided, the yield in the solid lithium ion battery production process is greatly improved, the expansion of each part of the solid lithium ion battery in the charging and discharging process can be inhibited, the battery has higher structural stability, and the cycle performance of the battery is effectively improved.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a solid-state lithium ion battery pole piece, which comprises a current collector and an electrode layer arranged on at least one side surface of the current collector, wherein a solid electrolyte layer is arranged on the electrode layer in a surface laminating manner on one side far away from the current collector, edge sealing layers are arranged on the periphery of the electrode layer and the periphery of the solid electrolyte layer, one side surface of each edge sealing layer is attached to the current collector, and each edge sealing layer comprises a first solid electrolyte.

According to the invention, the edge sealing layer containing the first solid electrolyte is arranged around the electrode layer and the solid electrolyte layer, on one hand, the edge sealing layer can fix the electrode layer and the solid electrolyte layer and prevent the active material and the electrolyte in the middle from expanding or deviating; on the other hand, the edge sealing layer contains solid electrolyte, the solid electrolyte has certain viscosity, when the solid lithium ion battery is prepared, the positive and negative plates are attached, the edge sealing layer can fix the positive and negative plates, prevent the positive and negative plates from being contacted with each other due to the deformation of the plates under high pressure, prevent the positive and negative plates from being misplaced, avoid the short circuit defect in the preparation process of the battery, greatly improve the yield in the production process of the solid lithium ion battery, and also can inhibit the expansion of each part of the solid lithium ion battery in the charging and discharging process, so that the battery has higher structural stability, thereby effectively improving the cycle performance of the battery; meanwhile, the solid electrolyte is selected as the edge sealing layer, so that impurities can be prevented from being generated, and if some ceramic materials are selected, powder can enter the active layer or the solid electrolyte layer, some local side reactions can be generated, the electrical property is influenced, and the self-discharge of the battery is increased or the capacity exertion is not normal. Therefore, the solid lithium ion battery pole piece can effectively solve the problem of battery abnormity and cycle performance reduction caused by structural change caused by expansion during battery assembly or charging and discharging, and improves the cycle performance and safety performance of the battery.

Preferably, the direction from the electrode layer to the edge sealing layer around the periphery is a width direction, and the width of the edge sealing layer is 0.5-30 mm, and may be, for example, 0.5mm, 1mm, 2mm, 3mm, 5mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm, 30mm, or the like.

According to the invention, the edge sealing layer has a proper width, so that when the width of the edge sealing layer is too large, the energy density of the battery can be influenced, and when the width of the edge sealing layer is smaller, the edge sealing effect can be influenced, so that the phenomenon of contact short circuit of the battery can still occur after edge sealing.

It should be noted that, in the present invention, the width of the edge sealing layer refers to the total width of the edge sealing layer, and the edge sealing layer is disposed around the periphery of the electrode layer, it can be understood that the electrode layers are disposed on both sides of the electrode layer in the width direction, and the width of the electrode layer refers to the total width of both sides.

The thickness of the solid electrolyte layer is preferably 5 to 200. Mu.m, and may be, for example, 5 μm, 10 μm, 20 μm, 50 μm, 60 μm, 80 μm, 100 μm, 150 μm, 200 μm, or the like, preferably 50 to 100 μm.

Preferably, the total thickness of the electrode layer and the solid electrolyte layer is 5 to 30 μm higher than the thickness of the edge sealing layer, for example, 5 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 26 μm, 28mm, 30mm, or the like; or

The total thickness of the electrode layer and the solid electrolyte layer is 5 to 30 μm smaller than the thickness of the edge sealing layer, and may be, for example, 5 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 26 μm, 28mm, 30mm, or the like.

In the invention, the total thickness of the electrode layer and the solid electrolyte layer is 5-30 μm higher than that of the edge sealing layer, or 5-30 μm lower than that of the edge sealing layer, that is, the top of the edge sealing layer can exceed the solid electrolyte layer by 5-30 μm, or be 5-30 μm lower than that of the solid electrolyte layer. When the top of the edge sealing layer exceeds the solid electrolyte layer by 5-30 mu m, the compression ratio of the edge sealing layer slurry is larger than the compression ratio of the electrode layer and the solid electrolyte layer, and in the compaction process, the positive electrode and the negative electrode can be in better contact and the current collector is smoother when the positive electrode and the negative electrode are compacted together due to the thickness difference of 5-30 mu m; when the top of the edge sealing layer is 5-30 μm lower than the solid electrolyte layer, the solid electrolyte layer is pressed down in the compaction process, and the edge sealing layers of the positive and negative pole pieces are just in contact with each other, so that the positive and negative pole pieces can be prevented from being compacted too tightly. However, when the thickness of the edge sealing layer is too high, the phenomenon of thick edge after pressing can occur, so that the phenomenon of damage and short circuit can occur in a partial area, when the thickness of the edge sealing layer is too small, the thickness fault phenomenon can occur after the solid electrolyte layer covers the surface of the electrode, and the contact and the engagement of the solid electrolyte layer and the edge sealing layer can not occur due to the too small thickness, so that the contact and short circuit condition of the battery can occur.

It should be noted that, the thickness of the electrode layer is not specifically required and limited in the present invention, and the thickness of the electrode layer commonly used in the prior art can be applied, for example, the thickness of the electrode layer in the positive electrode is generally 200 μm, 250 μm and 280 μm, etc., the thickness of the electrode layer in the negative electrode is generally 300 μm, etc., and the different thicknesses of the systems are different, and those skilled in the art can adjust the thickness of the electrode layer according to the selected system.

As a preferable technical solution of the solid-state lithium ion battery pole piece of the present invention, the solid-state electrolyte layer includes a second solid-state electrolyte and a binder.

Preferably, the edge sealing layer comprises a binder in addition to the first solid-state electrolyte.

Preferably, the mass ratio of the first solid electrolyte to the binder in the edge sealing layer is (50-100): (1-50), wherein the selection range of the first solid electrolyte (50-100) can be, for example, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100, etc., and the selection range of the binder (1-50) can be, for example, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45 or 50, etc.

Preferably, the mass ratio of the second solid electrolyte to the binder in the solid electrolyte layer is (80-100): 0-20, the content of the binder is not 0, and the binder needs to be added in the solid electrolyte layer to ensure that the electrolyte slurry does not fall off and peel after being coated and dried; wherein the selection range (80-100) of the second solid electrolyte can be, for example, 80, 86, 90, 95 or 100, etc., and the selection range (0-20) of the binder can be, for example, 0.1, 1, 2, 5, 8, 10, 15 or 20, etc.

In the invention, the most appropriate mass ratio ranges of the solid electrolyte and the binder in the edge sealing layer and the solid electrolyte layer are different in size, because the conductivity is influenced by the higher content of the binder, and the edge sealing layer does not need to conduct ions, so that the binder proportion can be selected to be higher than that of the solid electrolyte layer; the solid electrolyte layer requires a suitable binder content because it needs to be ion conductive.

As a preferable technical scheme of the solid lithium ion battery pole piece, the electrode layer comprises an electrode active substance, a conductive material, a third solid electrolyte and a binder.

Preferably, the mass ratio of the electrode active material, the conductive material, the third solid electrolyte and the binder in the electrode layer is (50-95): (1-5): (5-50): (1-10), wherein the selection range of the electrode active material (50-95) can be, for example, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, etc., the selection range of the conductive material (1-5) can be, for example, 1, 2, 3, 4, 5, etc., the selection range of the third solid electrolyte (5-50) can be, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, etc., and the selection range of the binder (1-10) can be, for example, 1, 2, 5, 8, 10, etc.

Preferably, the binder in the solid electrolyte layer and the binder in the capping layer independently include any one or a combination of at least two of polyvinylidene chloride, polyvinylidene fluoride-hexafluoropropylene, polytetrafluoroethylene, polyethylene oxide, polyester, polyamide, polyamideimide, polymethyl methacrylate, polycarbonate, carboxymethyl cellulose, styrene-butadiene copolymer, polyacrylonitrile, polyacrylic acid, ethylene-butadiene-styrene block copolymer, sodium carboxymethyl cellulose, and styrene-butadiene rubber, for example, a combination of polyvinylidene chloride and polyvinylidene chloride-hexafluoropropylene, a combination of polyvinylidene fluoride, polyamide, and polyamideimide, a combination of sodium carboxymethyl cellulose and styrene-butadiene rubber, or a combination of carboxymethyl cellulose, styrene-butadiene copolymer, and polyacrylonitrile, or the like.

Preferably, the electrode active material includes a positive electrode active material or a negative electrode active material.

In the present invention, the use of the solid-state lithium ion battery pole piece as the positive electrode or the negative electrode is not specifically limited, and a person skilled in the art can select the corresponding positive electrode active material or negative electrode active material according to the use of the solid-state lithium ion battery pole piece as the positive electrode or the negative electrode.

Illustratively, the positive electrode active material includes any one of or a combination of at least two of lithium cobaltate, lithium nickelate, lithium manganate, lithium nickelate, lithium nickel cobaltate, lithium phosphate, lithium nickel cobalt aluminate and lithium nickel cobalt manganate, and may be, for example, a combination of lithium cobaltate and lithium nickelate, a combination of lithium manganate and lithium nickel manganate, or a combination of lithium nickelate, lithium manganate and lithium nickel cobalt manganate, and the like.

Illustratively, the negative active material includes graphite, silicon oxide carbon composite (SiO) _x Any one or combination of at least two of/C) and silicon-carbon composite (Si/C), such as graphite, silicon oxide-carbon composite (SiO) _x Combination of/C), silicon oxide carbon composite (SiO) _x Combination of/C) and silicon-carbon composite (Si/C), or graphite, silicon oxide-carbon composite (SiO) _x A combination of/C) and silicon-carbon composite (Si/C), and the like.

Preferably, the conductive material includes any one or a combination of at least two of carbon black, acetylene black, carbon nanotubes, carbon fibers, graphene and graphene oxide, and may be, for example, a combination of carbon black and acetylene black, a combination of carbon fibers and graphene, or a combination of carbon black, acetylene black, carbon fibers and graphene.

Preferably, the binder in the electrode layer includes any one of polyvinylidene chloride, polyvinylidene chloride-hexafluoropropylene, polytetrafluoroethylene, polyethylene oxide, polyester, polyamide, polyamideimide, polymethyl methacrylate, polycarbonate, carboxymethyl cellulose, styrene-butadiene copolymer, polyacrylonitrile, sodium carboxymethyl cellulose, and styrene-butadiene rubber, or a combination of at least two thereof, and for example, may be a combination of polyvinylidene chloride and polyvinylidene chloride-hexafluoropropylene, a combination of polyamide and polyamideimide, a combination of sodium carboxymethyl cellulose and styrene-butadiene rubber, or a combination of carboxymethyl cellulose, styrene-butadiene copolymer, and polyacrylonitrile, or the like.

Preferably, the first, second and third solid-state electrolytes independently comprise any one of an oxide solid-state electrolyte, a sulfide solid-state electrolyte, a selenide solid-state electrolyte and a polymer solid-state electrolyte, or a combination of at least two thereof, preferably a sulfide solid-state electrolyte.

It should be noted that "independently" in the present invention means that the selection of two or three of them are not mutually interfered, for example, the first solid electrolyte, the second solid electrolyte and the third solid electrolyte independently include any one or a combination of at least two of an oxide solid electrolyte, a sulfide solid electrolyte, a selenide solid electrolyte and a polymer solid electrolyte, when the first solid electrolyte is an oxide solid electrolyte, the second solid electrolyte may be an oxide solid electrolyte, a sulfide solid electrolyte, a selenide solid electrolyte and the like, and the third solid electrolyte may be an oxide solid electrolyte, a sulfide solid electrolyte, a selenide solid electrolyte and the like, and the selection of the first solid electrolyte, the second solid electrolyte and the third solid electrolyte is also mutually interfered, but preferably all of the three are sulfide solid electrolytes.

Illustratively, the oxide solid state electrolytes include, but are not limited to: (anti-) perovskite structure (Li) ₂ O-La ₂ O ₃ -TiO ₂ Basal system), NASICON type structure (Li) ₂ O-P ₂ O ₅ -TiO ₂ Radicals or Li ₂ O-P ₂ O ₅ -GeO ₂ Base system) and garnet structure (Li) ₂ O-Ln ₂ O ₃ -BO ₂ Radical system (Ln = one or more of lanthanides, B = Zr and/or Sn) material.

Illustratively, the sulfide solid state electrolytes include, but are not limited to: li ₂ S-P ₂ S ₅ 、Li ₂ S-GeS ₂ Or Li ₂ S-SiS ₂ Based on binary sulfides and Li ₂ S-P ₂ S ₅ -MeS ₂ (Me = Si, ge, sn, etc.) group or Li ₂ S-P ₂ S ₅ -LiX (X = Cl, br, I, etc.) based ternary sulfide solid state electrolyte material.

As a preferred technical solution of the solid lithium ion battery pole piece of the present invention, a superposed layer is further disposed between the electrode layer and the solid electrolyte layer, a side edge of the superposed layer is attached to the edge sealing layer, and the superposed layer includes the first solid electrolyte.

In the invention, the side edge of the superposed layer is attached to the edge sealing layer, both the superposed layer and the edge sealing layer contain the first solid electrolyte, the superposed layer can be regarded as a part of the edge sealing layer, namely the edge sealing layer extends to a position between the electrode layer and the solid electrolyte layer along the horizontal direction, and the superposed layer is formed between the two layers (between the peripheral edge positions of the two layers), so that the electrode layer, the solid electrolyte layer and the edge sealing layer can be in better contact, and the combination effect among the reinforced layers can be realized.

Preferably, the width of the overlapping layer is 0.2-1 mm, such as 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm, etc. along the direction from the electrode layer to the edge sealing layer around the periphery.

In a second aspect, the present invention provides a method for preparing a solid-state lithium ion battery electrode plate according to the first aspect, wherein the preparation method comprises:

coating electrode layer slurry on at least one side surface of a current collector to obtain an electrode layer, coating edge sealing layer slurry on the periphery of the electrode layer to obtain an edge sealing layer, and coating solid electrolyte layer slurry on the surface of the electrode layer to obtain a solid electrolyte layer, thus obtaining the solid lithium ion battery pole piece.

The invention can realize the uniformity and controllability of the edge sealing layer prepared by the electrode, has simple preparation process, is suitable for large-scale production and has higher industrial application prospect.

Preferably, the coating of the electrode layer slurry on at least one side surface of the current collector to obtain the electrode layer comprises:

mixing an electrode active substance, a conductive material, a second solid electrolyte, a binder and a solvent to obtain an electrode layer slurry, coating the electrode layer slurry on at least one side surface of a current collector, reserving a hollow foil area with the width of 0.5-30 mm at the periphery of the current collector for coating the edge sealing layer slurry, and drying to obtain the electrode layer.

The 0.5 to 30mm area of the hollow foil of the present invention may be, for example, 0.5mm, 1mm, 2mm, 3mm, 5mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm, 30mm, or the like.

Illustratively, the solvent in the electrode layer paste includes any one or a combination of at least two of toluene, xylene, ethanol, benzene, and chlorobenzene, and may be, for example, a combination of toluene and xylene, a combination of ethanol and benzene, or a combination of xylene, ethanol, benzene, and chlorobenzene, or the like.

Preferably, the coating of the edge sealing layer slurry around the periphery of the electrode layer to obtain the edge sealing layer comprises:

mixing a first solid electrolyte, a binder and a solvent to obtain edge sealing layer slurry, coating the edge sealing layer slurry on a hollow foil area on the surface of the current collector, and drying to form an edge sealing layer around the periphery of the electrode layer.

Preferably, in the process of coating the edge sealing layer slurry on the empty foil area of the surface of the current collector, a part of edge sealing layer slurry is also coated on the surface of the electrode layer, and a superposed layer with the width of 0.2-1 mm is formed on the surface of the electrode layer.

It should be noted that, when the edge banding layer slurry is applied to the surface of the current collector and around the periphery of the electrode layer, the edge banding layer, the electrode layer and the solid electrolyte layer coated subsequently are perfectly contacted, but in actual coating, in order to prevent poor contact, a part of the edge banding layer slurry is applied to the surface of the electrode layer, and an overlapping area with the width of 0.2-1 mm is formed between the electrode layer and the solid electrolyte layer, so that the bonding effect among the electrode layer, the solid electrolyte layer and the edge banding layer is further enhanced.

Preferably, the step of applying the solid electrolyte layer slurry to the surface of the electrode layer to obtain the solid electrolyte layer comprises:

and mixing a second solid electrolyte, a binder and a solvent to obtain solid electrolyte slurry, coating the solid electrolyte slurry on the surface of the electrode layer, and drying to obtain the solid electrolyte layer.

Illustratively, the solvent in the solid electrolyte layer slurry and the solvent in the electrode layer slurry include any one or a combination of at least two of toluene, xylene, ethanol, benzene, and chlorobenzene, and may be, for example, a combination of toluene and xylene, a combination of ethanol and benzene, or a combination of xylene, ethanol, benzene, and chlorobenzene, or the like.

As a preferable technical scheme of the preparation method of the invention, the preparation method comprises the following steps:

(1) Mixing an electrode active substance, a conductive material, a second solid electrolyte, a binder and a solvent to obtain an electrode layer slurry, coating the electrode layer slurry on at least one side surface of a current collector, reserving a hollow foil area with the width of 0.5-30 mm at the periphery of the current collector for coating the edge sealing layer slurry, and drying to obtain an electrode layer;

(2) Mixing a first solid electrolyte, a binder and a solvent to obtain edge sealing layer slurry, coating the edge sealing layer slurry on a hollow foil area on the surface of the current collector, coating partial edge sealing layer slurry on the surface of the electrode layer, drying, forming edge sealing layers around the periphery of the electrode layer, and forming a superposition layer with the width of 0.2-1 mm on the surface of the electrode layer;

(3) And mixing a second solid electrolyte, a binder and a solvent to obtain solid electrolyte slurry, coating the solid electrolyte slurry on the surface of the electrode layer, and drying to obtain a solid electrolyte layer, thereby completing the preparation of the solid lithium ion battery pole piece.

It should be noted that, the preparation order of the electrode layer slurry, the edge sealing layer slurry and the solid electrolyte slurry in the step (1), the step (2) and the step (3), and the coating immediately after the slurry preparation or the coating sequentially according to the order after all the slurry preparations are completed are not specifically limited, for example, the preparation of the electrode layer slurry, the edge sealing layer slurry and the solid electrolyte slurry can be completed first, the preparation of the three slurries is not limited, and then the electrode layer slurry, the edge sealing layer slurry and the solid electrolyte slurry are sequentially coated; or preparing electrode layer slurry, coating to obtain an electrode layer, preparing edge sealing layer slurry, coating, and the like.

In a third aspect, the present invention provides a solid-state lithium ion battery, where the solid-state lithium ion battery includes a positive electrode and a negative electrode, and the positive electrode and/or the negative electrode employs the solid-state lithium ion battery electrode sheet according to the first aspect.

The battery prepared by the solid lithium ion battery pole piece has high yield, is not easy to expand, has strong structural stability and has good cycling stability.

Preferably, the positive electrode and the negative electrode both adopt the solid-state lithium ion battery pole piece according to the first aspect, and the edge sealing layer of the positive electrode is attached to the edge sealing layer of the negative electrode.

When the positive and negative electrodes of the battery adopt the solid-state lithium ion battery pole pieces, the edge sealing layers of the positive and negative electrodes are attached and firmly bonded together, so that the positive and negative pole pieces can be effectively prevented from being dislocated, the deformation and the expansion in the production process of the battery are further prevented, and the electrochemical performance of the battery is improved.

Preferably, the solid-state lithium ion battery is prepared as follows:

and (3) placing the anode and the cathode in a fitting manner, fitting the edge sealing layer of the anode and the edge sealing layer of the cathode, and rolling to obtain the solid-state lithium ion battery.

Preferably, the rolling pressure is 1 to 50T, for example, 1T, 5T, 10T, 15T, 20T, 25T, 30T, 35T, 40T, 45T, 50T, etc., and the rolling temperature is 0 to 110 ℃, for example, 0 ℃, 10 ℃, 20 ℃, 30 ℃, 40 ℃, 50 ℃, 80 ℃, 100 ℃ or 110 ℃, etc.

Compared with the prior art, the invention has the following beneficial effects:

according to the invention, the edge sealing layers containing the first solid electrolyte are arranged on the peripheries of the electrode layer and the solid electrolyte layer, and the solid lithium ion battery pole piece structure can better fix the positive and negative pole pieces, prevent the pole pieces from position deformation under large pressure, so that the positive and negative pole edges are contacted, the short circuit defect in the battery preparation process is avoided, and the yield in the solid battery production process is greatly improved; meanwhile, the expansion of each part of the solid-state battery in the charging and discharging process can be inhibited, so that the battery has higher structural stability, and the electrochemical performance of the all-solid-state sulfide battery is effectively improved; the invention can realize the uniformity and controllability of the edge sealing layer prepared by the electrode, has simple preparation process of the pole piece, is suitable for large-scale production and has higher industrial application prospect.

Drawings

Fig. 1 is a schematic side view of a solid-state lithium ion battery electrode plate according to an embodiment of the present invention.

Fig. 2 is a schematic plane structure diagram of a solid-state lithium ion battery pole piece according to an embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a solid-state lithium ion battery according to an embodiment of the present invention.

Wherein, 1-a current collector; 2-an electrode layer; 3-edge sealing layer; 4-solid electrolyte layer.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitation of the present invention.

The invention provides a solid-state lithium ion battery pole piece, which is shown in fig. 1 and fig. 2 in a schematic structural diagram, and comprises a current collector 1 and an electrode layer 2 arranged on at least one side surface of the current collector 1, wherein a solid electrolyte layer 4 is arranged on the electrode layer 2 in a surface lamination manner on one side far away from the current collector 1, edge sealing layers 3 are arranged on the periphery of the electrode layer 2 and the periphery of the solid electrolyte layer 4, one side surface of each edge sealing layer 3 is attached to the current collector 1, and each edge sealing layer 3 comprises a first solid electrolyte.

In some embodiments, the thickness of the edge banding layer 3 is 20 to 250 μm, preferably 50 to 100 μm.

In some embodiments, the direction from the electrode layer 2 to the edge sealing layer 3 around the periphery is a width direction, and the width of the edge sealing layer 3 is 0.5 to 30mm.

In some embodiments, the thickness of the solid electrolyte layer 4 is 5 to 200 μm;

further, the thickness of the solid electrolyte layer 4 is 50 to 100 μm.

In some embodiments, the total thickness of the electrode layer 2 and the solid electrolyte layer 4 is 5 to 30 μm higher than the thickness of the edge sealing layer 3; or

The total thickness of the electrode layer 2 and the solid electrolyte layer 4 is 5 to 30 μm lower than the thickness of the edge sealing layer 3.

In some embodiments, the solid electrolyte layer 4 comprises a second solid electrolyte and a binder.

In some embodiments, the capping layer 3 comprises a binder in addition to the first solid-state electrolyte.

In some embodiments, the mass ratio of the first solid electrolyte and the binder in the sealing layer 3 is (50-100): 1-50.

In some embodiments, the mass ratio of the second solid electrolyte to the binder in the solid electrolyte layer 4 is (80-100): 0-20, and the content of the binder is not 0.

In some embodiments, the electrode layer 2 includes an electrode active material, a conductive material, a third solid electrolyte, and a binder.

In some embodiments, the mass ratio of the electrode active material, the conductive material, the third solid electrolyte and the binder in the electrode layer 2 is (50-95): (1-5): (5-50): (1-10).

In some embodiments, the electrode active material includes a positive electrode active material or a negative electrode active material.

In some embodiments, the first, second and third solid-state electrolytes independently comprise any one of an oxide solid-state electrolyte, a sulfide solid-state electrolyte, a selenide solid-state electrolyte and a polymer solid-state electrolyte, or a combination of at least two thereof, preferably a sulfide solid-state electrolyte.

In some embodiments, a superposed layer is further disposed between the electrode layer 2 and the solid electrolyte layer 4, and the side edge of the superposed layer is attached to the edge sealing layer 3, and the superposed layer includes the first solid electrolyte.

In some embodiments, the width direction is from the electrode layer 2 to the edge sealing layer 3 around the periphery, and the width of the overlapping layer is 0.2 to 1mm.

The specific embodiment of the invention also provides a preparation method of the solid-state lithium ion battery pole piece, which comprises the following steps:

coating electrode layer slurry on at least one side surface of a current collector 1 to obtain an electrode layer 2, coating edge sealing layer slurry on the periphery of the electrode layer 2 to obtain an edge sealing layer 3, and coating solid electrolyte layer slurry on the surface of the electrode layer 2 to obtain a solid electrolyte layer 4, so as to obtain the solid lithium ion battery pole piece.

In some embodiments, the applying the electrode layer slurry on at least one side surface of the current collector 1 to obtain the electrode layer 2 includes:

mixing an electrode active substance, a conductive material, a second solid electrolyte, a binder and a solvent to obtain electrode layer slurry, coating the electrode layer slurry on at least one side surface of a current collector 1, reserving a hollow foil area with the width of 0.5-30 mm around the current collector 1 for coating edge sealing layer slurry, and drying to obtain an electrode layer 2.

In some embodiments, the step of applying the edge sealing layer slurry around the periphery of the electrode layer 2 to obtain the edge sealing layer 3 includes:

mixing a first solid electrolyte, a binder and a solvent to obtain edge sealing layer slurry, coating the edge sealing layer slurry to an empty foil area on the surface of the current collector 1, and drying to form an edge sealing layer 3 around the periphery of the electrode layer 2.

In some embodiments, during the process of applying the edge sealing layer slurry to the empty foil area on the surface of the current collector 1, a partial edge sealing layer slurry is also applied to the surface of the electrode layer 2, and a superposed layer with a width of 0.2-1 mm is formed on the surface of the electrode layer 2.

In some embodiments, the applying the solid electrolyte layer slurry to the surface of the electrode layer 2 to obtain the solid electrolyte layer 4 includes:

and mixing a second solid electrolyte, a binder and a solvent to obtain solid electrolyte slurry, coating the solid electrolyte slurry on the surface of the electrode layer 2, and drying to obtain the solid electrolyte layer 4.

In some embodiments, the method of making comprises:

(1) Mixing an electrode active substance, a conductive material, a second solid electrolyte, a binder and a solvent to obtain electrode layer slurry, coating the electrode layer slurry on at least one side surface of a current collector 1, reserving a hollow foil area with the width of 0.5-30 mm at the periphery of the current collector 1 for coating edge sealing layer slurry, and drying to obtain an electrode layer 2;

(2) Mixing a first solid electrolyte, a binder and a solvent to obtain edge sealing layer slurry, coating the edge sealing layer slurry to an empty foil area on the surface of the current collector 1, coating part of the edge sealing layer slurry to the surface of the electrode layer 2, drying, forming an edge sealing layer 3 around the periphery of the electrode layer 2, and forming a superposition layer with the width of 0.2-1 mm on the surface of the electrode layer 2;

(3) And mixing a second solid electrolyte, a binder and a solvent to obtain solid electrolyte slurry, coating the solid electrolyte slurry on the surface of the electrode layer 2, and drying to obtain a solid electrolyte layer 4, thereby completing the preparation of the solid lithium ion battery pole piece.

The specific embodiment of the invention also provides a solid-state lithium ion battery, the structural schematic diagram of which is shown in fig. 3, the solid-state lithium ion battery comprises a positive electrode and a negative electrode, and the positive electrode and/or the negative electrode adopt the solid-state lithium ion battery pole piece.

In some embodiments, the positive electrode and the negative electrode both use the above solid-state lithium ion battery pole piece, and the edge sealing layer 3 of the positive electrode and the edge sealing layer 3 of the negative electrode are attached to each other.

Example 1

The embodiment provides a solid-state lithium ion battery pole piece for a negative electrode, which is characterized in that a schematic side structure diagram is shown in fig. 1, and a schematic plane structure diagram is shown in fig. 2, the solid-state lithium ion battery pole piece comprises a current collector 1 and a carbon-coated copper foil and an electrode layer 2 arranged on one side surface of the current collector 1, a solid electrolyte layer 4 is arranged on the electrode layer 2 in a laminated manner on one side surface far away from the current collector 1, edge sealing layers 3 are arranged on the periphery of the electrode layer 2 and the periphery of the solid electrolyte layer 4, and one side surface of each edge sealing layer 3 is attached to the current collector 1;

the electrode layer 2 includes graphite, which is a negative electrode active material, and Li, in a mass ratio of 70 ₆ PS ₅ Cl sulfide solid electrolyte, conductive carbon and polyacrylic acid, wherein the edge sealing layer 3 comprises Li with the mass ratio of 100 ₆ PS ₅ A Cl sulfide solid electrolyte and a binder polyacrylic acid, the solid electrolyte layer 4 including Li in a mass ratio of 100 ₆ PS ₅ Cl sulfide solid electrolyte and adhesive polyacrylic acid; the size of the current collector 1 is 85 × 155mm, the sizes of the electrode layer 2 and the solid electrolyte layer 4 are both 80 × 130mm, the width direction is from the electrode layer 2 to the peripheral edge sealing layer 3, the width of the edge sealing layer 3 is 5mm (the total width of two sides is 5mm, the width of one side is 2.5 mm), the thickness of the electrode layer 2 is 315 μm, the thickness of the solid electrolyte layer 4 is 80 μm, and the thickness of the edge sealing layer 3 is 10 μm higher than the total thickness of the electrode layer 2 and the solid electrolyte layer 4.

The embodiment also provides a preparation method of the solid-state lithium ion battery pole piece for the negative electrode, which comprises the following steps:

(1) Graphite, li, which is a negative electrode active material of 70 ₆ PS ₅ Mixing Cl sulfide solid electrolyte, conductive carbon, polyacrylic acid and a xylene solvent to obtain cathode electrode layer slurry; mixing Li ₆ PS ₅ Placing the Cl sulfide solid electrolyte and a binder polyacrylic acid (the mass ratio of the Cl sulfide solid electrolyte to the binder polyacrylic acid is 100; mixing Li ₆ PS ₅ Placing the Cl sulfide solid electrolyte and a binder polyacrylic acid (the mass ratio of the Cl sulfide solid electrolyte to the binder polyacrylic acid is 100: 1.5) in a xylene solvent, and mixing to obtain cathode solid electrolyte slurry;

(2) Coating the cathode electrode layer slurry obtained in the step (1) on the surface of one side, coated with the carbon copper foil, of a current collector 1 with the thickness of 85 × 155mm, coating the surface with the size of 80 × 130mm, reserving an empty foil area with the width of 5mm at the periphery of the current collector 1 for coating edge sealing layer slurry, and drying to obtain an electrode layer 2;

(3) Coating the slurry of the negative electrode edge sealing layer obtained in the step (1) to an empty foil area on the surface of the current collector 1, wherein the coating width of the edge sealing layer 3 is 5mm, and drying to form the edge sealing layer 3 around the periphery of the electrode layer 2;

(4) And (2) coating the cathode solid electrolyte slurry obtained in the step (1) on the surface of the electrode layer 2, wherein the coating size is 80 × 130mm which is the same as that of the electrode layer 2, and the thickness of the edge sealing layer 3 is 10 μm higher than that of the surface of the solid electrolyte layer 4, and drying to obtain the solid lithium ion battery pole piece for the cathode.

The embodiment also provides a schematic side structure diagram of a solid-state lithium ion battery pole piece for the anode, which is shown in fig. 1, and a schematic plan structure diagram is shown in fig. 2, the solid-state lithium ion battery pole piece comprises a current collector 1 aluminum foil and an electrode layer 2 arranged on one side surface of the current collector 1, the electrode layer 2 is provided with a solid electrolyte layer 4 on one side surface far away from the current collector 1 in a laminated manner, edge sealing layers 3 are arranged on the periphery of the electrode layer 2 and the periphery of the solid electrolyte layer 4, and one side surface of the edge sealing layer 3 is attached to the current collector 1;

the electrode layer 2 includes positive electrode active materials NCM811 and Li in a mass ratio of 80 ₆ PS ₅ Cl sulfide solid electrolyte, conductive carbon and polyacrylic acid, wherein the edge sealing layer 3 comprises Li with the mass ratio of 100 ₆ PS ₅ A Cl sulfide solid electrolyte and a binder polyacrylic acid, the solid electrolyte layer 4 including Li in a mass ratio of 100 ₆ PS ₅ Cl sulfide solid electrolyte and adhesive polyacrylic acid; the size of the current collector 1 is 84 × 154mm, the sizes of the electrode layer 2 and the solid electrolyte layer 4 are 77 × 127mm, the width direction is the direction from the electrode layer 2 to the peripheral edge sealing layer 3, the width of the edge sealing layer 3 is 7mm (the total width of two sides is 7mm, the width of one side is 3.5 mm), the thickness of the electrode layer 2 is 295 μm, the thickness of the solid electrolyte layer 4 is 110 μm, and the thickness of the edge sealing layer 3 is 10 μm higher than the total thickness of the electrode layer 2 and the solid electrolyte layer 4.

The embodiment also provides a preparation method of the solid-state lithium ion battery pole piece for the positive electrode, which comprises the following steps:

(1) Positive electrode active material graphite and Li in mass ratio of 80 ₆ PS ₅ Mixing Cl sulfide solid electrolyte, conductive carbon, polyacrylic acid and a xylene solvent to obtain anode electrode layer slurry; mixing Li ₆ PS ₅ Placing Cl sulfide solid electrolyte and polyacrylic acid (the mass ratio of the Cl sulfide solid electrolyte to the polyacrylic acid is 100; mixing Li ₆ PS ₅ Placing Cl sulfide solid electrolyte and polyacrylic acid (the mass ratio of the Cl sulfide solid electrolyte to the polyacrylic acid is 100;

(2) Coating the positive electrode layer slurry obtained in the step (1) on one side surface of an aluminum foil of a current collector 1 with the size of 77 x 127mm, reserving an empty foil area with the width of 7mm at the periphery of the current collector 1 for coating the edge sealing layer slurry, and drying to obtain an electrode layer 2;

(3) Coating the slurry of the positive edge sealing layer obtained in the step (1) to a hollow foil area on the surface of the current collector 1, wherein the coating width of the edge sealing layer 3 is 7mm, and drying to form the edge sealing layer 3 around the periphery of the electrode layer 2;

(4) And (2) coating the positive electrode solid electrolyte slurry obtained in the step (1) on the surface of the electrode layer 2, wherein the coating size is 77 x 127mm which is the same as that of the electrode layer 2, and the thickness of the edge sealing layer 3 is 10 micrometers higher than that of the surface of the solid electrolyte layer 4, and drying to obtain the solid lithium ion battery pole piece for the positive electrode.

The embodiment also provides a solid lithium ion battery, a schematic structural diagram of which is shown in fig. 3, and the solid lithium ion battery comprises the solid lithium ion battery pole piece for the positive electrode and the solid lithium ion battery pole piece for the negative electrode, and the edge sealing layers 3 of the two pole pieces are attached to each other, and the preparation method comprises the following steps:

placing the solid lithium ion battery pole piece used for the positive electrode on the solid lithium ion battery pole piece used for the negative electrode, attaching the edge sealing layers 3 of the two pole pieces, pre-rolling by using a roller press to ensure that the two pole pieces are preliminarily attached, wherein the rolling pressure is 20T, the rolling temperature is 90 ℃, then performing isostatic pressing, the isostatic pressing pressure is 550MPa, the dwell time is 5min, and the isostatic pressing temperature is 45 ℃, and preparing the solid lithium ion battery.

Example 2

The same procedure as in example 1 was repeated, except that the width of the edge sealing layer 3 in the solid-state lithium-ion battery electrode sheet for the negative electrode was changed to 10mm, and the width of the edge sealing layer 3 in the solid-state lithium-ion battery electrode sheet for the positive electrode was changed to 12 mm.

Example 3

The same as example 1 was repeated except that the thickness of the edge sealing layer 3 in each of the solid lithium ion battery electrode sheet for negative electrode and the solid lithium ion battery electrode sheet for positive electrode was adjusted to be 30 μm higher than the surface of the solid electrolyte layer 4.

Example 4

Except Li of solid electrolyte layer 4 in solid lithium ion battery pole piece used for negative electrode ₆ PS ₅ Cl sulfide solid electrolyteReplacement by Li _6.5 La ₃ Zr _1.5 Ta _0.5 O ₁₂ The rest of the oxide solid electrolyte was the same as in example 1.

Example 5

Except Li of edge sealing layer 3 in solid lithium ion battery pole piece to be used for negative electrode ₆ PS ₅ Replacement of Cl sulfide solid electrolyte by Li _6.5 La ₃ Zr _1.5 Ta _0.5 O ₁₂ The procedure of example 1 was repeated except for the oxide solid electrolyte.

Example 6

The same procedure as in example 1 was repeated, except that the thickness of the edge sealing layer 3 in each of the solid lithium ion battery electrode sheet for negative electrode and the solid lithium ion battery electrode sheet for positive electrode was adjusted to be 10 μm lower than the surface of the solid electrolyte layer 4 (i.e., the thickness of the edge sealing layer 3 was 10 μm smaller than the total thickness of the electrode layer 2 and the solid electrolyte layer 4).

Example 7

The same procedure as in example 1 was repeated except that the thickness of the edge sealing layer 3 in each of the solid lithium ion battery electrode piece for the negative electrode and the solid lithium ion battery electrode piece for the positive electrode was adjusted to be 30 μm lower than the surface of the solid electrolyte layer 4.

Example 8

The same as example 1 was repeated except that the thickness of the edge sealing layer 3 in each of the solid lithium ion battery electrode sheet for negative electrode and the solid lithium ion battery electrode sheet for positive electrode was adjusted to be 40 μm higher than the surface of the solid electrolyte layer 4.

Example 9

The thickness of the edge sealing layer 3 in the solid-state lithium ion battery pole piece for the negative electrode and the solid-state lithium ion battery pole piece for the positive electrode was adjusted to be equal to that of the solid-state electrolyte layer 4 (i.e., the thickness of the edge sealing layer 3 was equal to the total thickness of the electrode layer 2 and the solid-state electrolyte layer 4), and the rest was the same as that of example 1.

Example 10

Except that a 0.5mm wide overlapping layer is arranged between the electrode layer 2 and the solid electrolyte layer 4 of the solid lithium ion battery pole piece for the negative electrode and the solid lithium ion battery pole piece for the positive electrode, the side edge of the overlapping layer is attached to the edge sealing layer 3, the materials of the overlapping layer and the edge sealing layer 3 are the same, and the rest is the same as that of the embodiment 1;

in the embodiment, the overlapping layer is prepared by applying partial edge sealing layer slurry to the surface of the electrode layer 2 when applying the edge sealing layer slurry in the step (3).

Example 11

The procedure of example 1 was repeated except that the width of the edge sealing layer 3 in the negative electrode-use solid-state lithium-ion battery electrode sheet was adjusted to 0.5 mm.

Comparative example 1

Except that the edge sealing layers 3 in the solid-state lithium ion battery pole piece for the negative electrode and the solid-state lithium ion battery pole piece for the positive electrode were omitted, the rest were the same as those in example 1.

Comparative example 2

The same procedure as in example 1 was repeated, except that the thickness of the edge sealing layer 3 in each of the negative electrode-use solid lithium ion battery electrode sheet and the positive electrode-use solid lithium ion battery electrode sheet was adjusted to be 30 μm lower than the surface of the electrode layer 2 (i.e., the thickness of the edge sealing layer 3 was 30 μm lower than the thickness of the electrode layer 2).

Comparative example 3

Except that the material of the edge sealing layer 3 is replaced by ceramic Al ₂ O ₃ Otherwise, the same as in example 1 was repeated.

Performance testing

The solid-state lithium ion batteries prepared in examples 1 to 11 and comparative examples 1 to 3 were subjected to yield test and cycle performance test:

the good product rate test is to perform charge and discharge tests after the batteries are subjected to isostatic pressing, the good product rate is obtained by dividing the number of the batteries passing the tests by the total number of the batteries to be tested, and the test results are shown in table 1;

the cycle performance test is to charge and discharge the battery at a rate of 0.5C, the voltage interval is 3.0-4.25V, the battery is charged and discharged for 400 times in a cycle, the first discharge capacity and the 400 th discharge capacity of the battery are recorded, the 400 th discharge capacity is divided by the first discharge capacity to obtain the capacity retention rate after 400 cycles, and the test results are shown in Table 1.

TABLE 1

Detailed description of the preferred embodiments	Battery yield (50 pcs)	Capacity retention after 400 cycles
			Example 1	95％	94.3％
Example 2	97％	91.7％
			Example 3	98％	90.5％
Example 4	97％	92.4％
			Example 5	98％	90.9％
Example 6	96％	93.2％
			Example 7	97％	92.4％
Example 8	87％	91.2％
			Example 9	94％	92.6％
Example 10	98％	95.3％
			Example 11	90％	93.8％
Comparative example 1	73％	87.6％
			Comparative example 2	82％	90.3％
Comparative example 3	65％	88.6％

To sum up, the embodiments 1 to 11 show that, by arranging the edge sealing layer 3 containing the solid electrolyte around the electrode layer 2 and the solid electrolyte layer 4, the invention can fix the positive and negative electrode plates, prevent the electrode plates from deforming under a large pressure to cause the contact of the positive and negative electrode edges, avoid the short circuit defect in the battery preparation process, greatly improve the yield in the solid lithium ion battery production process, and inhibit the expansion of each component of the solid lithium ion battery in the charging and discharging process, so that the battery has higher structural stability, thereby effectively improving the cycle performance of the battery.

It can be seen from the comparison among the examples 1, 3, and 6-8 that, in the present invention, when the thickness of the edge sealing layer 3 is higher or lower than the thickness of the electrode layer 2 and the solid electrolyte layer 4 by 5-30 μm, the good product yield and the cycle performance are both good, but when the height of the edge sealing layer 3 is higher (higher by 40 μm in example 8) or lower, the edge sealing layer is not good for the adhesion of the positive and negative edge sealing layers 3 and the flatness of the current collector 1, so the battery cycle performance of the examples 1 and 6 is better.

It can be seen from comparison among examples 1, 5 and comparative example 3 that the performance of the edge banding layer 3 of the present invention is best when the material is a solid electrolyte, and is most preferably a sulfide solid electrolyte, because the ionic conductivity of an oxide solid electrolyte is low, the performance of a battery is affected when the oxide solid electrolyte enters an electrode layer during a preparation process, and the compaction rate of a ceramic material is low, and the ceramic material cannot be pressed to a required thickness, so that the edge banding effect is poor, and the yield of a product is reduced, and therefore, the performance of the comparative example 3 is significantly inferior to that of examples 1 and 5.

As can be seen from the comparison between example 1 and example 10, the bonding performance between the electrode layer 2, the solid electrolyte layer 4 and the edge sealing layer 3 is further enhanced by the provision of the overlapping layer, and the safety and cycle performance of the battery are finally improved.

Compared with the comparative example 1 which does not adopt the edge sealing structure, the edge sealing of the electrodes in the examples 1 to 11 of the invention can effectively improve the battery abnormity caused by displacement deformation generated by high pressure in the processing process, and can also effectively inhibit the deformation expansion of each component of the battery in the charging and discharging process, thereby effectively improving the battery cycle performance, when the edge sealing thickness of the electrodes is smaller than the thickness of the electrode layer 2, the battery qualification rate is obviously reduced, and the displacement deformation of the solid electrolyte layer 4 and the active layer occurs under large pressure, so that the short circuit phenomenon occurs in the battery, thereby reducing the qualification rate in the battery preparation process, therefore, the technical scheme adopted by the invention can effectively overcome the short circuit abnormity caused by electrode contact in the preparation process of the solid battery, and can also effectively improve the component expansion defect generated in the charging and discharging process, thereby enabling the battery to have higher structural stability.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the protection scope and the disclosure of the present invention.

Claims

1. The utility model provides a solid-state lithium ion battery pole piece, a serial communication port, solid-state lithium ion battery pole piece includes the mass flow body and sets up the electrode layer of the at least side surface of the mass flow body, the electrode layer is keeping away from one side surface lamination of the mass flow body is provided with the solid state electrolyte layer, the periphery of electrode layer all around with the periphery on solid state electrolyte layer is provided with the banding layer all around, a side surface on banding layer with the mass flow body is laminated mutually, the banding layer includes first solid state electrolyte.

2. The solid-state lithium ion battery pole piece of claim 1, wherein the edge sealing layer has a thickness of 20 to 250 μm, preferably 50 to 100 μm;

preferably, the direction from the electrode layer to the edge sealing layer on the periphery is the width direction, and the width of the edge sealing layer is 0.5-30 mm;

preferably, the thickness of the solid electrolyte layer is 5 to 200 μm, preferably 50 to 100 μm;

preferably, the total thickness of the electrode layer and the solid electrolyte layer is 5-30 μm higher than the thickness of the edge sealing layer; or

The total thickness of the electrode layer and the solid electrolyte layer is 5-30 μm lower than the thickness of the edge sealing layer.

3. The solid state lithium ion battery pole piece of claim 1 or 2, wherein the solid state electrolyte layer comprises a second solid state electrolyte and a binder;

preferably, the sealing layer comprises a binder in addition to the first solid-state electrolyte;

preferably, the mass ratio of the first solid electrolyte to the binder in the edge sealing layer is (50-100): 1-50;

preferably, the mass ratio of the second solid electrolyte to the binder in the solid electrolyte layer is (80-100): (0-20), and the content of the binder is not 0.

4. The solid state lithium ion battery pole piece of any one of claims 1-3, wherein the electrode layer comprises an electrode active material, a conductive material, a third solid state electrolyte, and a binder;

preferably, the mass ratio of the electrode active material, the conductive material, the third solid electrolyte and the binder in the electrode layer is (50-95): (1-5): (5-50): (1-10);

preferably, the electrode active material includes a positive electrode active material or a negative electrode active material;

preferably, the first, second and third solid-state electrolytes independently comprise any one of an oxide solid-state electrolyte, a sulfide solid-state electrolyte, a selenide solid-state electrolyte and a polymer solid-state electrolyte or a combination of at least two thereof, preferably a sulfide solid-state electrolyte.

5. The solid-state lithium ion battery pole piece of any one of claims 1-4, wherein a coincident layer is further disposed between the electrode layer and the solid-state electrolyte layer, a side edge of the coincident layer is attached to the edge sealing layer, and the coincident layer comprises the first solid-state electrolyte;

preferably, the direction from the electrode layer to the edge sealing layer around the periphery is the width direction, and the width of the overlapping layer is 0.2-1 mm.

6. The preparation method of the solid-state lithium ion battery pole piece according to any one of claims 1 to 5, wherein the preparation method comprises the following steps:

7. The preparation method according to claim 6, wherein the step of coating the electrode layer slurry on at least one side surface of the current collector to obtain the electrode layer comprises the following steps:

mixing an electrode active substance, a conductive material, a second solid electrolyte, a binder and a solvent to obtain an electrode layer slurry, coating the electrode layer slurry on at least one side surface of a current collector, reserving a hollow foil area with the width of 0.5-30 mm at the periphery of the current collector for coating the edge sealing layer slurry, and drying to obtain an electrode layer;

preferably, the step of coating the edge sealing layer slurry around the periphery of the electrode layer to obtain the edge sealing layer comprises the following steps:

mixing a first solid electrolyte, a binder and a solvent to obtain edge sealing layer slurry, coating the edge sealing layer slurry on a hollow foil area on the surface of the current collector, and drying to form an edge sealing layer on the periphery of the electrode layer;

preferably, in the process of coating the edge sealing layer slurry on the empty foil area of the surface of the current collector, a part of edge sealing layer slurry is also coated on the surface of the electrode layer, and a superposed layer with the width of 0.2-1 mm is formed on the surface of the electrode layer;

8. The production method according to claim 6 or 7, characterized by comprising:

(3) And mixing a second solid electrolyte, a binder and a solvent to obtain solid electrolyte slurry, coating the solid electrolyte slurry on the surface of the electrode layer, and drying to obtain a solid electrolyte layer to finish the preparation of the solid lithium ion battery pole piece.

9. A solid-state lithium ion battery is characterized in that the solid-state lithium ion battery comprises a positive electrode and a negative electrode, and the positive electrode and/or the negative electrode adopts the solid-state lithium ion battery pole piece according to any one of claims 1 to 5.

10. The solid-state lithium ion battery of claim 9, wherein the positive electrode and the negative electrode both adopt the solid-state lithium ion battery pole piece of any one of claims 1 to 5, and the edge sealing layer of the positive electrode is attached to the edge sealing layer of the negative electrode.