Composite electrode tab and method of making same

Abstract

The application discloses a composite electrode tab. According to an embodiment of the application, the composite electrode tab comprises: an electrode tab; a solid-state electrolyte layer arranged on both sides of the electrode tab; a curable layer arranged on a side of the solid-state electrolyte layer away from the electrode tab; and a protective layer arranged on a side of the curable layer away from the solid-state electrolyte layer. The composite electrode tab according to the embodiment of the application can improve the first cycle efficiency of a battery, thereby improving the performance of the battery.

Description

Composite electrodes and their preparation methods Technical Field

[0001] This application relates to the field of battery technology, specifically to composite electrodes and their preparation methods. More specifically, it relates to solid-state batteries, battery packs, and electronic devices. Background Technology

[0002] Lithium-ion batteries, with their high energy density and good cycle stability, are among the most widely used energy storage systems. With the development and popularization of new energy vehicles, the safety of lithium-ion batteries has gradually gained attention. However, liquid lithium-ion batteries are prone to explosion under extreme conditions such as mechanical damage, high temperatures, and short circuits, causing safety accidents. Compared to liquid lithium batteries, solid-state lithium batteries offer higher safety and energy density.

[0003] However, solid-state batteries also face many challenges. Current solid-state battery fabrication processes suffer from poor solid-solid interface contact, high manufacturing difficulty, and significant material loss. Therefore, it is necessary to design and improve the battery structure to achieve continuous manufacturing processes with good interface contact, lower manufacturing difficulty, and less material loss, thereby promoting the rapid development of the solid-state battery industry. Summary of the Invention

[0004] In a first aspect, this application proposes a composite electrode. According to an embodiment of this application, the composite electrode includes: an electrode sheet; a solid electrolyte layer disposed on both sides of the electrode sheet; a curable layer disposed on the side of the solid electrolyte layer away from the electrode sheet; and a protective layer disposed on the side of the curable layer away from the solid electrolyte layer. The composite electrode according to the embodiment of this application can improve the first-cycle efficiency of a battery, thereby improving battery performance.

[0005] In some embodiments, the thickness of the electrode sheet is 80–200 μm.

[0006] In some embodiments, the thickness of the solid electrolyte layer is 20–150 μm.

[0007] In some embodiments, the thickness of the curable layer is 4–7 μm.

[0008] In some embodiments, the thickness of the protective layer is 3–20 μm.

[0009] In some embodiments, the curable layer includes at least one of a matrix material, an ion-conducting filler, a curing agent, and an initiator.

[0010] In some embodiments, the matrix material is selected from at least one of ionic liquid-based composite materials, polymer-based composite materials, and ion exchange resin-based materials.

[0011] In some embodiments, the ion-conducting filler is selected from at least one of ion salt-based composite materials and nano-ion conductor-based composite materials.

[0012] In some embodiments, the solid electrolyte is selected from at least one of oxide solid electrolytes, sulfide solid electrolytes, halide solid electrolytes, hydride solid electrolytes, boride solid electrolytes, and nitride solid electrolytes.

[0013] In some embodiments, the protective film is selected from at least one of silicone release film, fluorine release film, PET film, PP film, PE film, PE / PP film, PP / PE / PP film, PE / PP / PE film and non-silicone release film.

[0014] In some embodiments, the electrode plates include at least one of a positive electrode plate and a negative electrode plate.

[0015] In some embodiments, the ion-conducting filler accounts for 5-15 wt% of the curable layer.

[0016] In some embodiments, the ion-conducting filler accounts for 8-12 wt% of the curable layer.

[0017] In a second aspect, this application provides a method for preparing the composite electrode sheet described in the first aspect. According to an embodiment of this application, the method includes: coating both sides of the electrode sheet to form the solid electrolyte layer; coating the side of the solid electrolyte layer away from the electrode sheet to form the curable layer; and coating the side of the curable layer away from the solid electrolyte layer to form the protective layer. The method according to the embodiment of this application can prepare a composite electrode sheet that improves the first-cycle efficiency of the battery, thereby enhancing battery performance.

[0018] In a third aspect of this application, a method for preparing a solid-state battery having the composite electrode described in the first aspect of this application is proposed. According to an embodiment of this application, the method includes: preparing the composite electrode by the method described in the second aspect of this application, and performing a curing treatment to obtain a solid-state battery.

[0019] In some embodiments, the curing temperature is 80–160°C, and the curing time is 0.5–2 hours.

[0020] In a fourth aspect, this application proposes a solid-state battery. According to an embodiment of this application, the solid-state battery includes the composite electrode described in the first aspect of this application. The solid-state battery according to the embodiment of this application exhibits improved performance.

[0021] In a fifth aspect of this application, a battery pack is proposed. According to an embodiment of this application, the battery pack includes the solid-state battery described in the fourth aspect of this application.

[0022] In a sixth aspect, this application proposes an electronic device. According to an embodiment of this application, the electronic device includes the battery pack described in the fifth aspect of this application.

[0023] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0024] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0025] Figure 1 is a schematic diagram of the structure of a composite electrode according to an embodiment of this application.

[0026] Figure 2 shows the electrochemical performance results of a battery prepared according to an embodiment of this application during the first week.

[0027] Figure 3 shows the electrochemical performance results of a battery prepared according to an embodiment of this application during the first week.

[0028] Figure 4 shows the electrochemical performance results of a battery prepared according to an embodiment of this application during the first week.

[0029] Figure 5 shows the electrochemical performance results of a comparative battery prepared according to this application during the first week.

[0030] Explanation of reference numerals in the attached figures:

[0031] Electrode sheet 01; solid electrolyte layer 02; curable layer 03; protective layer 04; composite electrode sheet 100. Detailed Implementation

[0032] The embodiments of this application are described in detail below, with examples of these embodiments shown in the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0033] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit this application; unless otherwise stated, the values ​​of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art (e.g., they can be tested according to the methods given in the embodiments of this application).

[0034] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are open-ended expressions, meaning they include what is specified in this application but do not exclude other aspects.

[0035] In the description of this application, it should be understood that the terms "width", "thickness", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0036] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. "First feature" and "second feature" may include one or more of the indicated feature.

[0037] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0038] In the description of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0039] In the description of this application, "multiple" means two or more.

[0040] In the description of this application, "A and / or B" can include any of the cases of A alone, B alone, or A and B, where A and B are merely examples and can be any technical feature connected by "and / or" in this application.

[0041] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0042] Lithium-ion batteries, with their advantages of high energy density, high output power, and long cycle life, are widely used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, as well as in electric vehicles, electric motorcycles, electric bicycles, power tools, military equipment, aerospace, and many other fields. With the development and popularization of new energy vehicles, the safety of lithium-ion batteries has gradually received attention. However, liquid lithium-ion batteries are prone to explosion under extreme conditions such as mechanical damage, high temperatures, and short circuits, causing safety accidents. Compared with liquid lithium batteries, solid-state lithium batteries offer higher safety and energy density.

[0043] However, solid-state batteries also face many challenges. Poor solid-solid interface contact leads to rapid capacity decay; stringent process requirements at each stage of battery production hinder continuous production; and significant material loss during manufacturing reduces yield and increases costs. These factors severely restrict the practical application of solid-state lithium batteries. Therefore, it is necessary to design and improve battery structures to achieve continuous manufacturing processes with good interface contact, lower process complexity, and less material loss, thereby promoting the rapid development of the solid-state battery industry.

[0044] In view of this, in a first aspect of this application, a composite electrode is proposed. According to an embodiment of this application, referring to FIG1, the composite electrode 100 includes: an electrode 01; a solid electrolyte layer 02 disposed on both sides of the electrode 01; a curable layer 03 disposed on the side of the solid electrolyte layer 02 away from the electrode 01; and a protective layer 04 disposed on the side of the curable layer 03 away from the solid electrolyte layer 02. According to embodiments of this application, the protective layer can prevent material friction during the rolling and winding process, ensuring a smooth electrode surface and reducing edge scraping and burrs during die-cutting, thus minimizing material loss. Both the protective layer and the curable layer have a certain degree of elasticity, which can release inter-particle stress during rolling, ensuring consistent lateral thickness of the electrode. Composite electrodes are easier to fix during stacking, greatly reducing stacking difficulty, optimizing the industrial manufacturing process of solid-state batteries, and improving economic efficiency. Composite electrodes can effectively solve the short-circuit problem caused by dendrite growth, and the high-strength curable layer can prevent dendrite puncture, ensuring battery safety performance. The curable layer acts as an isolation layer, separating the electrode sheet and the solid electrolyte layer, preventing side reactions between them, and improving the battery's charge-discharge efficiency and long-term cycle stability. The curable layer can improve the solid-solid interface inside the battery; the in-situ cured interface has good interfacial contact, promoting ion transport and thus improving the battery's charge-discharge performance. The composite electrode according to embodiments of this application can improve the battery's first-cycle efficiency, thereby improving battery performance.

[0045] In some embodiments, the thickness of the electrode sheet is 80–200 μm, for example, it can be 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, or a range between the two, such as 90–200 μm or 100–200 μm. According to embodiments of this application, if the electrode sheet thickness is too low, it will reduce the mass energy density of the solid-state battery system; if the electrode sheet thickness is too high, it will reduce the internal ion transport rate and the mass reaction rate, affecting the battery's rate discharge performance. A moderate electrode sheet thickness is beneficial for improving the battery's energy density while ensuring high-rate charge-discharge performance.

[0046] In some embodiments, the thickness of the solid electrolyte layer is 20–150 μm, for example, it can be 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm, 150 μm, or a range between the two, such as 25–150 μm or 30–150 μm. According to the embodiments of this application, if the thickness of the solid electrolyte layer is too low, the mechanical strength will decrease, making it more prone to cracking and deformation, and increasing the risk of internal short circuits in the battery. If the thickness of the solid electrolyte layer is too high, the battery energy density will decrease, and the ion migration path will increase, reducing the ion transport efficiency. A moderate thickness of the solid electrolyte layer is beneficial to improving the battery energy density and safety performance, and increasing the ion transport efficiency.

[0047] In some embodiments, the thickness of the curable layer is 4–7 μm, for example, it can be 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, or a range of 4.5–7 μm between the two. According to the embodiments of this application, if the thickness of the curable layer is too low, the curing layer will be uneven, failing to prevent side reactions inside the battery and increasing the difficulty of electrode manufacturing. If the thickness of the curable layer is too high, it will increase the internal impedance of the battery, which is not conducive to mass transport. A moderate thickness of the curable layer is beneficial to enhancing the solid-solid contact interface inside the battery and promoting ion migration.

[0048] In some embodiments, the thickness of the protective layer is 3–20 μm, for example, it can be 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, or a range between the two, 4–20 μm or 5–20 μm. According to the embodiments of this application, if the thickness of the protective layer is too low, it will be unable to withstand the tension during the rolling process and will break, increasing the manufacturing difficulty. If the thickness of the protective layer is too high, it will increase material costs and the difficulty of rolling and winding. A moderate thickness of the protective layer is beneficial for optimizing the manufacturing process and reducing production costs.

[0049] In some embodiments, the curable layer includes at least one of a matrix material, an ion-conducting filler, a curing agent, and an initiator.

[0050] In some embodiments, the matrix material is selected from at least one of ionic liquid-based composite materials, polymer-based composite materials, and ion exchange resin-based materials.

[0051] In some embodiments, the ionic liquid-based composite material, such as imidazole or pyrrolidone ionic liquids, can form a continuous phase after curing, combining the functions of matrix and ion conduction, for example, a gel electrolyte.

[0052] In some embodiments, the polymer-based composite material, such as polyethylene oxide or polyvinylidene fluoride, forms a continuous network through molecular chains, for example, a polymer matrix in a solid electrolyte.

[0053] In some embodiments, the ion exchange resin, such as sulfonated polystyrene, can provide mechanical strength through its own three-dimensional network structure and serve as a matrix for ion transport, such as an ion exchange membrane.

[0054] In some embodiments, the ion-conducting filler is selected from at least one of ion salt-based composite materials and nano-ion conductor-based composite materials.

[0055] In some embodiments, the ionic salt-based composite material, such as ionic salts like LiTFSI and LiPF6, is dissolved or dispersed in the matrix to provide conductivity through free ions, such as lithium salts in liquid or polymer electrolytes.

[0056] In some embodiments, the nano-ion conductor-based composite materials, such as LLZO and LATP-type nanoscale ion conductor particles, optimize ion transport paths through surface or interface effects, for example, composite electrolytes reinforced with ceramic fillers.

[0057] Those skilled in the art will know that a curable layer is a mixture of various substances. This application only limits the types of curable layers and does not limit auxiliary materials such as curing agents and initiators. All curing agents and initiators that can cure materials under certain conditions and do not react with solid electrolytes are applicable to this application.

[0058] In some embodiments, the solid electrolyte is an inorganic solid electrolyte.

[0059] In some embodiments, the solid electrolyte is selected from at least one of oxide solid electrolytes, sulfide solid electrolytes, halide solid electrolytes, hydride solid electrolytes, boride solid electrolytes, and nitride solid electrolytes.

[0060] In some embodiments, the protective film is selected from at least one of silicone release film, fluorine release film, PET film, PP film, PE film, PE / PP film, PP / PE / PP film, PE / PP / PE film and non-silicone release film.

[0061] In some embodiments, the oxide solid electrolyte comprises one or more garnet ceramics, LISICON-type oxides, NASICON-type oxides, and perovskite ceramics. For example, one or more garnet ceramics include, but are not limited to, Li 0.25 , 12 , 2-x , x , 1+x , x , x , 3+x , 2-x , 0.25 , 1+x , 6.75 , 0.3 , 1-x , 12 , 3+x , 6.25 , 1.3 , 1-x , 0.25 , x , 12 , 2-x , 1.75 , 1+x , 1.7 , x La3Zr 1.75 Te 0.25 O 12 、Li7La3Zr2O 12 、Li 6.2 Ga 0.3 La 2.95 Rb 0.05 Zr2O 12 、Li 6.85 La 2.9 Ca 0.1 Zr 1.75 Nb 0.25 O 12 、Li 6.25 Al 0.25 La3Zr2O 12 、Li 6.75 La3Zr 1.75 Nb 0.25 O 12 among one or more of them. One or more LISICON-type oxides include, but are not limited to, Li14Zn(GeO4)4, Li 3+x (P 1-x Si x )O4 (where 0 < x < 1), Li 3+x Ge x V 1-x O4 (where 0 < x < 1) among one or more of them. One or more NASICON-type oxides can be defined by LiMM′(PO4)3, where M and M′ are independently selected from Al, Ge, Ti, Sn, Hf, Zr, and La. For example, in certain variations, one or more NASICON-type oxides include, but are not limited to, Li 1+x Al x Ge 2-x (PO4)3 (LAGP) (where 0 ≤ x ≤ 2), Li 1+x Al x Ti 2-x (PO4)3 (LATP) (where 0 ≤ x ≤ 2), Li 1+x Y x Zr 2-x (PO4)3 (LYZP) (where 0 ≤ x ≤ 2), Li 1.3 Al 0.3 Ti 1.7One or more of (PO4)3, LiTi2(PO4)3, LiGeTi(PO4)3, LiGe2(PO4)3, LiHf2(PO4)3. One or more perovskite-type ceramics include, but are not limited to, Li 3.3 La 0.53 TiO3, LiSr 1.65 Zr 1.3 Ta 1.7 O9, Li 2x-y Sr 1-x Ta y Zr 1-y O3 (where x = 0.75y and 0.60 < y < 0.75), Li 3 / 8 Sr 7 / 16 Nb 3 / 4 Zr 1 / 4 O3, Li 3x La (2 / 3-x) TiO3 (where 0 < x < 0.25).

[0062] In some embodiments, the sulfide solid electrolyte includes, but is not limited to, Li2S-P2S5, Li2S-P2S5-MS x (where M is Si, Ge, and Sn and 0 ≤ x ≤ 2), Li 3.4 Si 0.4 P 0.6 S4, Li 10 GeP2S 11.7 O 0.3 、Li 9.6 P3S 12 、Li7P3S 11 、Li9P3S9O3, Li 10.35 Si 1.35 P 1.65 S 12 、Li 9.81 Sn 0.81 P 2.19 S 12 、Li 10 (Si 0.5 Ge 0.5 )P2S 12 、Li(Ge 0.5 Sn 0.5 )P2S 12 、Li(Si 0.5 Sn 0.5 )PsS 12 、Li 10 GeP2S 12 (LGPS), Li6PS5X (where X is Cl, Br, or I), Li7P2S8I, Li 10.35Ge 1.35 P 1.65 S 12 、Li 3.25 Ge 0.25 P 0.75 S4、Li 10 SnP2S 12 、Li 10 SiP2S 12 、Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 、(1 - x)P2S 5-x Li2S (where 0.5 ≤ x ≤ 0.7) or more of them.

[0063] In some embodiments, the halide solid electrolyte includes but is not limited to Li2CdC l4 、Li2MgC l4 、Li2CdI4, Li2ZnI4, Li3OCl, LiI, Li5ZnI4, Li3OCl 1-x [[ID=四十一]]Br x (where 0 < x < 1) or more of them.

[0064] In some embodiments, the boride solid electrolyte includes but is not limited to one or more of Li2B4O7, Li2O-(B2O3)-(P2O5).

[0065] In some embodiments, the nitride solid electrolyte includes but is not limited to one or more of Li3N, Li7PN4, LiSi2N3, LiPON.

[0066] In some embodiments, the hydride solid electrolyte includes but is not limited to one or more of Li3AlH6, LiBH4, LiBH4-LiX (where X is one of Cl, Br, and I), LiNH2, Li2NH, LiBH4-LiNH2.

[0067] In some embodiments, the inorganic solid electrolyte can be one or more metal oxide particles or lithium-containing compounds, including but not limited to one or more of Al2O3, SiO2, TiO2, LiNbO3, Li4Ti5O4, Li3PO4.

[0068] In some embodiments, the electrode sheet includes at least one of the positive electrode sheet and the negative electrode sheet.

[0069] In some embodiments, the ion-conducting filler accounts for 5-15 wt% of the curable layer, for example, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, or 15 wt%.

[0070] In some embodiments, the ion-conducting filler accounts for 8-12 wt% of the curable layer.

[0071] In a second aspect, this application discloses a method for preparing a composite electrode. According to an embodiment of this application, the method includes: coating both sides of the electrode to form a solid electrolyte layer; coating the side of the solid electrolyte layer away from the electrode to form a curable layer; and coating the side of the curable layer away from the solid electrolyte layer to form a protective layer. The method according to the embodiment of this application can prepare a composite electrode that improves the first-cycle efficiency of the battery, thereby enhancing battery performance.

[0072] In one specific embodiment of this application, a single-layer solid electrolyte layer is bonded to the surface of a double-layer electrode, and the composite is performed and wound up under a certain pressure using a rolling device. Then, the electrode sheet of the required size is obtained by die cutting, and finally the protective film is peeled off to obtain the composite electrode sheet.

[0073] In some embodiments, the double-layer electrode is a positive electrode or a negative electrode, and further includes a double-layer electrode with a positive electrode on one side and a negative electrode on the other side.

[0074] In some embodiments, the positive electrode includes a dry-process positive electrode and a wet-process positive electrode. The positive electrode active material layer is formed of a positive electrode active material comprising one or more transition metal cations, wherein the transition metals include at least one of manganese (Mn), nickel (Ni), cobalt (Co), chromium (Cr), iron (Fe), and vanadium (V). The positive electrode active material is selected from at least one of layered oxides, spinel, and polyanionic materials. For example, the layered oxide (rock salt layered oxide) comprises one or more lithium-based positive electrode active materials selected from LiCoO2 (LCO), LiNi, etc. x Mn y Co 1-x-y O2 (where 0 ≤ x ≤ 1 and 0 ≤ y ≤ 1), LiNi 1-x-y Co x Al y O2 (where 0 ≤ x ≤ 1 and 0 ≤ y ≤ 1), LiNi x Mn 1-x O2 (where 0 ≤ x ≤ 1), and Li 1+xMO2 (where M is one of Mn, Ni, Co, and Al and 0 ≤ x ≤ 1). Spinel contains one or more lithium-based cathode active materials selected from the following: LiMn2O4 (LMO) and LiNi. x Mn 1.5 O4. Olivine type comprises one or more lithium-based cathode active materials, LiMPO4 (where M is at least one of Fe, Ni, Co, and Mn). Polyanionic cations comprise, for example, phosphates such as LiV2(PO4)3 and / or silicates such as LiFeSiO4.

[0075] In some embodiments, the negative electrode can be a silicon-based negative electrode active material comprising, for example, silicon alloys, silicon oxide, or combinations thereof, and in some cases, it may be mixed with graphite. The negative electrode sheet can be a carbon-based negative electrode active material comprising one or more of graphite, graphene, carbon nanotubes (CNTs), and combinations thereof. The negative electrode sheet may also include one or more lithium-accepting negative electrode active materials, such as lithium titanium oxide (Li4Ti5O). 12 One or more transition metals (e.g., tin (Sn)), one or more metal oxides (e.g., vanadium oxide (V₂O₅), tin oxide (SnO), titanium dioxide (TiO₂)), titanium niobium oxide (Ti) x Nb y O z , where 0≤x≤2, 0≤y≤24 and 0≤z≤64, metal alloys (such as copper-tin alloy (Cu6Sn5)) and one or more metal sulfides (such as iron sulfide (FeS)).

[0076] In a third aspect of this application, a method for preparing a solid-state battery having the composite electrode described in the first aspect of this application is proposed. According to an embodiment of this application, the method includes: preparing the composite electrode by the method described in the second aspect of this application, and performing a curing treatment to obtain a solid-state battery.

[0077] In some embodiments, the curing temperature is 80–160°C, and the curing time is 0.5–2 hours.

[0078] In some embodiments, the composite electrode (negative electrode) obtained in the first aspect of this application is bonded to the positive electrode to form a battery structure unit. Multiple units are combined to form a pouch cell, which is then welded and packaged to obtain a single battery cell. The battery is then treated under certain conditions to cure the internal curable layer, resulting in a solid-state battery with a composite electrode.

[0079] Those skilled in the art will understand that when the aforementioned multifunctional composite electrode is the negative electrode, the electrode bonded to it is the positive electrode; when the multifunctional composite electrode is the positive electrode, the electrode bonded to it is the negative electrode; and when one side is the positive electrode and the other side is the negative electrode, the corresponding electrodes are the negative and positive electrodes. In other words, the fabricated solid-state battery has various structural combinations, but this does not affect the structure of the multifunctional composite electrode of this application.

[0080] In some embodiments, this application does not require the number of layers in a single cell; the number should be determined based on actual needs.

[0081] In some embodiments, the curing method described above includes one or more of thermal curing, microwave curing, and photocuring used together.

[0082] In some embodiments, the thermosetting temperature is 80–160°C, for example, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, or a range between the two, 90–160°C, 100–160°C, preferably 100–120°C, and the curing time is 0.5–2 hours, for example, 0.5 hours, 0.6 hours, 0.7 hours, 0.8 hours, 0.9 hours, 1 hour, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours, 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours, 2 hours, or a range between the two, 0.6–2 hours, 0.7–2 hours, preferably 0.5–1 hour.

[0083] In a fourth aspect, this application proposes a solid-state battery. According to an embodiment of this application, the solid-state battery includes the composite electrode described in the first aspect of this application. The solid-state battery according to the embodiment of this application exhibits improved performance.

[0084] In a fifth aspect of this application, a battery pack is proposed. According to an embodiment of this application, the battery pack includes the solid-state battery described in the fourth aspect of this application.

[0085] In a sixth aspect, this application proposes an electronic device. According to an embodiment of this application, the electronic device includes the battery pack described in the fifth aspect of this application.

[0086] The following will explain the solution of this application with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0087] In this embodiment, a solid electrolyte is incorporated into the negative electrode and then combined with the positive electrode to form a battery structural unit. Multiple units are combined to form a battery. The positive electrode, negative electrode, and solid electrolyte are respectively selected as ternary NCM811, silicon-oxygen negative electrode, and sulfide solid electrolyte. The curable layer uses epoxy resin material 3,4-epoxycycloethylmethyl (TTA21) or phenolic resin material, filled with modified ethylene oxide (PEO). The mass percentage of PEO in each layer is 10%. A PE film with a thickness of 10 μm is selected as the protective film.

[0088] Example 1:

[0089] A curable slurry TTA21-PEO and a sulfide solid electrolyte are coated onto a PE film on one side in multiple layers and dried at 60°C to obtain material A. The thickness of the curable layer is 5 μm, and the thickness of the solid electrolyte layer is 40 μm. A silicon-oxygen negative electrode is bonded to material A on both sides, rolled and then wound to obtain material B. Material B is die-cut, and the PE film on its surface is peeled off to obtain a composite electrode, referred to as material C. Material C is matched with an NCM811 positive electrode, and after stacking, welding, and encapsulation, a single cell D is obtained. Cell D is cured at 80°C for 0.5 h, and after cooling, a solid-state battery with a composite electrode is obtained.

[0090] Example 2:

[0091] The experimental process in this embodiment is basically the same as that in Embodiment 1. The difference is that the cell D is cured at 80°C for 1 hour and then cooled to obtain a solid-state battery with composite electrodes. The other processes are the same as in Embodiment 1.

[0092] Example 3:

[0093] The experimental process in this embodiment is basically the same as that in Embodiment 1. The difference is that the cell D is cured at 80°C for 1.5 hours and then cooled to obtain a solid-state battery with composite electrodes. The other processes are the same as in Embodiment 1.

[0094] Example 4:

[0095] The experimental process in this embodiment is basically the same as that in Embodiment 1. The difference is that the cell D is cured at 80°C for 2 hours and then cooled to obtain a solid-state battery with composite electrodes. The other processes are the same as in Embodiment 1.

[0096] Example 5:

[0097] The experimental process in this embodiment is basically the same as that in Embodiment 1. The difference is that the cell D is cured at 100°C for 1 hour and then cooled to obtain a solid-state battery with composite electrodes. The other processes are the same as in Embodiment 1.

[0098] Example 6:

[0099] The experimental process in this embodiment is basically the same as that in Embodiment 1. The difference is that the cell D is cured at 120°C for 1 hour and then cooled to obtain a solid-state battery with composite electrodes. The other processes are the same as in Embodiment 1.

[0100] Example 7:

[0101] The experimental process in this embodiment is basically the same as that in Embodiment 1. The difference is that the cell D is cured at 140°C for 1 hour and then cooled to obtain a solid-state battery with composite electrodes. The other processes are the same as in Embodiment 1.

[0102] Example 8:

[0103] The experimental process in this embodiment is basically the same as that in Embodiment 1. The difference is that the cell D is cured at 160°C for 1 hour and then cooled to obtain a solid-state battery with composite electrodes. The other processes are the same as in Embodiment 1.

[0104] Example 9:

[0105] The experimental process in this embodiment is basically the same as that in Embodiment 1. The difference is that the curable slurry is phenolic resin-PEO, and the cell D is cured at 80°C for 1 hour. After cooling, a solid-state battery with composite electrodes is obtained. The other processes are the same as in Embodiment 1.

[0106] Example 10:

[0107] The experimental process in this embodiment is basically the same as that in Embodiment 1. The difference is that the curable slurry is phenolic resin-PEO. The cell D is cured at 100°C for 1 hour and then cooled to obtain a solid-state battery with composite electrodes. The other processes are the same as in Embodiment 1.

[0108] Example 11:

[0109] The experimental process in this embodiment is basically the same as that in Embodiment 1. The difference is that the curable slurry is phenolic resin-PEO. Cell D is cured at 120°C for 1 hour and then cooled to obtain a solid-state battery with composite electrodes. The other processes are the same as in Embodiment 1.

[0110] Example 12:

[0111] The experimental process in this embodiment is basically the same as that in Embodiment 1. The difference is that the curable slurry is phenolic resin-PEO, and the cell D is cured at 140°C for 1 hour. After cooling, a solid-state battery with composite electrodes is obtained. The other processes are the same as in Embodiment 1.

[0112] Example 13:

[0113] The experimental process in this embodiment is basically the same as that in Embodiment 1. The difference is that the curable slurry is phenolic resin-PEO. Cell D is cured at 160°C for 1 hour and then cooled to obtain a solid-state battery with composite electrodes. The other processes are the same as in Embodiment 1.

[0114] Example 14:

[0115] The experimental process in this embodiment is basically the same as that in Embodiment 1, except that the curable slurry is phenolic resin-PEO, while the other processes are the same as in Embodiment 1.

[0116] Example 15:

[0117] The experimental process in this embodiment is basically the same as that in Embodiment 1, except that the thickness of the curable layer is 4μm, while the other processes are the same as in Embodiment 1.

[0118] Example 16:

[0119] The experimental process in this embodiment is basically the same as that in Embodiment 1, except that the thickness of the curable layer is 7 μm, while the other processes are the same as in Embodiment 1.

[0120] Example 17:

[0121] The experimental process in this embodiment is basically the same as that in Embodiment 1, except that the thickness of the curable layer is 3 μm, while the other processes are the same as in Embodiment 1.

[0122] Example 18:

[0123] The experimental process in this embodiment is basically the same as that in Embodiment 1, except that the thickness of the curable layer is 8 μm, while the other processes are the same as in Embodiment 1.

[0124] Example 19:

[0125] The experimental process in this embodiment is basically the same as that in Embodiment 1, except that the thickness of the solid electrolyte layer is 20 μm, while the other processes are the same as in Embodiment 1.

[0126] Example 20:

[0127] The experimental process in this embodiment is basically the same as that in Embodiment 1, except that the thickness of the solid electrolyte layer is 150 μm, while the other processes are the same as in Embodiment 1.

[0128] Example 21:

[0129] The experimental process in this embodiment is basically the same as that in Embodiment 1, except that the thickness of the solid electrolyte layer is 15 μm, while the other processes are the same as in Embodiment 1.

[0130] Example 22:

[0131] The experimental process in this embodiment is basically the same as that in Embodiment 1, except that the thickness of the solid electrolyte layer is 155 μm, while the other processes are the same as in Embodiment 1.

[0132] Example 23:

[0133] The experimental process in this embodiment is basically the same as that in Embodiment 1, except that the PE film on the surface is replaced with a PP film, while the other processes are the same as in Embodiment 1.

[0134] Comparative Example 1:

[0135] The experimental process in this embodiment is basically the same as that in Embodiment 1. The difference is that no curable slurry is added and the battery cell is not cured. The other processes are the same as in Embodiment 1.

[0136] Comparative Example 2:

[0137] The experimental process in this embodiment is basically the same as that in Embodiment 1, except that no PE film is added. The other processes are the same as in Embodiment 1.

[0138] All single-cell batteries obtained in the above examples and comparative examples underwent charge-discharge tests and cycle tests. The test temperature was 60°C, and the test voltage was 2.5–4.3V. Charge-discharge performance was tested at 0.1C, and cycle performance was tested at 1C. The electrochemical performance results of the battery prepared in Example 5 during the first week are shown in Figure 2, the battery prepared in Example 11 during the first week are shown in Figure 3, and the battery prepared in Comparative Example 1 without a curing layer during the first week are shown in Figure 4.

[0139] Table 1: Battery performance of Examples 1-23 and Comparative Examples 1-2

[0140]

[0141]

[0142] A comparison of Example 1 and Comparative Example 1 shows that adding a curable slurry is beneficial to improving battery performance, especially the first-cycle efficiency and capacity retention after 100 cycles.

[0143] A comparison of Example 1 and Comparative Example 2 shows that adding a PE film is beneficial to improving battery performance, especially the first-cycle efficiency and capacity retention after 100 cycles.

[0144] A comparison of Example 4 and Example 1 shows that a curing time of 2 hours is more beneficial to improving battery performance than a curing time of 0.5 hours, especially the first-cycle efficiency and the capacity retention rate after 100 cycles.

[0145] A comparison of Examples 5-8 with Examples 2, 10-13 and 9 shows that a curing temperature of 100℃-160℃ is more beneficial to improving battery performance than a curing temperature of 80℃, especially the first-cycle efficiency and the capacity retention rate after 100 cycles.

[0146] A comparison of Example 14 and Example 1 shows that TTA21-PEO curable slurry is more beneficial to improving battery performance than phenolic resin-PEO, especially the first-cycle efficiency and capacity retention after 100 cycles.

[0147] A comparison of Examples 1, 15-16 and Examples 17-18 shows that a curable layer thickness of 4-7 μm is more beneficial to improving battery performance, especially the first-cycle efficiency and capacity retention after 100 cycles, than a curable layer thickness of 3 μm or 8 μm.

[0148] A comparison of Examples 1, 19-20 and Examples 21-22 shows that a solid electrolyte layer thickness of 20-150 μm is more beneficial to improving battery performance, especially the first-cycle efficiency and capacity retention after 100 cycles, than a solid electrolyte layer thickness of 15 μm or 155 μm.

[0149] A comparison of Examples 1 and 23 shows that using a PE protective film is more beneficial to improving battery performance than using a PP protective film, especially the first-cycle efficiency and the capacity retention rate after 100 cycles.

[0150] A comparison of Example 1 and Comparative Example 1 shows that having a cured layer (i.e., a cured film) is more beneficial to improving battery performance than not having a cured layer, especially the first-cycle efficiency and the capacity retention rate after 100 cycles.

[0151] A comparison of Example 1 and Comparative Example 2 shows that adding a protective layer (i.e., a protective film) is more beneficial to improving battery performance than not adding a protective layer, especially the first-cycle efficiency and the capacity retention rate after 100 cycles.

[0152] In this specification, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0153] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A composite electrode, characterized in that, include: Electrode plates; A solid electrolyte layer is disposed on both sides of the electrode sheet; a curable layer is disposed on the side of the solid electrolyte layer away from the electrode sheet; a protective layer is disposed on the side of the curable layer away from the solid electrolyte layer, the curable layer comprising a matrix material, an ion-conducting filler, a curing agent, and an initiator; the matrix material is selected from at least one of ionic liquid-based composite materials, polymer-based composite materials, and ion exchange resin-based materials; the ion-conducting filler is selected from at least one of ionic salt-based composite materials and nano-ion conductor-based composite materials.

2. The composite electrode according to claim 1, characterized in that, The thickness of the electrode sheet is 80~200μm; and / or, the thickness of the solid electrolyte layer is 20~150μm; and / or, the thickness of the curable layer is 4~7μm; and / or, the thickness of the protective layer is 3~20μm.

3. The composite electrode according to claim 1, characterized in that, The solid electrolyte is selected from at least one of oxide solid electrolytes, sulfide solid electrolytes, halide solid electrolytes, hydride solid electrolytes, boride solid electrolytes, and nitride solid electrolytes; and / or, the protective layer is selected from at least one of silicone oil release film, fluorine release film, PET film, PP film, PE film, PE / PP film, PP / PE / PP film, PE / PP / PE film, and non-silicone release film; and / or, the electrode plates include at least one of positive electrode plates and negative electrode plates.

4. The composite electrode according to claim 3, characterized in that, The ion-conducting filler accounts for 5-15 wt% of the curable layer.

5. The composite electrode according to claim 4, characterized in that, The ion-conducting filler accounts for 8-12 wt% of the curable layer.

6. A method for preparing the composite electrode according to any one of claims 1 to 5, characterized in that, include: The solid electrolyte layer is coated on both sides of the electrode sheet; the curable layer is coated on the side of the solid electrolyte layer away from the electrode sheet. The protective layer is formed by coating the curable layer on the side away from the solid electrolyte layer.

7. A method for preparing a solid-state battery having the composite electrode according to any one of claims 1 to 5, characterized in that, include: The composite electrode is prepared by the method described in claim 6 and then cured to obtain a solid-state battery.

8. The method according to claim 7, characterized in that, The curing temperature is 80~160℃, and the curing time is 0.5~2h.

9. A solid-state battery, characterized in that, include: The composite electrode according to any one of claims 1 to 5.

10. A battery pack, characterized in that, include: The solid-state battery as described in several claims 9.

11. An electronic device, characterized in that, include: The battery pack of claim 10.

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