Solid-state battery and preparation method therefor, solid electrolyte membrane, electrolyte electrode sheet and electric device

Abstract

Disclosed are a solid-state battery and a preparation method therefor, a solid electrolyte membrane, an electrolyte electrode sheet and an electric device. The solid-state battery comprises a first electrode layer, a solid electrolyte layer and a second electrode layer, which are stacked in sequence, wherein the solid electrolyte layer comprises a first electrolyte layer, and the first electrolyte layer is located on the side of the solid electrolyte layer close to the first electrode layer; and the first electrolyte layer comprises a sulfide solid electrolyte and a first binder, and the first binder includes an amphiphilic binder.

Description

Solid-state batteries and their preparation methods, solid electrolyte membranes, electrolyte electrodes and electrical devices

[0001] Related applications

[0002] This application claims priority to Chinese patent application filed on November 8, 2024, with application number CN2024115992145, entitled "Solid-state battery and preparation method thereof, solid electrolyte membrane, electrolyte electrode and electrical device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of solid-state battery technology, and further to a solid-state battery and its preparation method, a solid electrolyte membrane, an electrolyte electrode, and an electrical device. Background Technology

[0004] The statements herein are provided only as background information in connection with this application and do not necessarily constitute prior art.

[0005] Solid-state batteries introduce non-flammable solid electrolytes to replace the organic electrolytes in traditional liquid secondary batteries, significantly improving battery safety. However, poor interfacial contact and interfacial side reactions are among the pain points limiting the performance of solid-state batteries, resulting in less than ideal cycle performance. Summary of the Invention

[0006] In view of the above problems, according to various embodiments and examples of this application, this application provides a solid-state battery and its preparation method, a solid electrolyte membrane, an electrolyte electrode, and an electrical device. This solid-state battery has improved cycle performance.

[0007] In some embodiments of the first aspect of this application, a solid-state battery is provided, comprising a first electrode layer, a solid electrolyte layer, and a second electrode layer stacked sequentially; wherein the solid electrolyte layer includes a first electrolyte layer, and the first electrolyte layer is located on the side of the solid electrolyte layer closer to the first electrode layer.

[0008] The first electrolyte layer comprises a sulfide solid electrolyte and a first binder, wherein the first binder comprises an amphiphilic binder.

[0009] In some embodiments, the amphiphilic adhesive includes hydrophilic and lipophilic groups.

[0010] The aforementioned solid-state battery has a first electrolyte layer comprising a sulfide solid electrolyte and a binder (which may be referred to as the first binder) disposed on the side of the solid electrolyte layer near the first electrode layer. By introducing an amphiphilic binder having both hydrophilic and lipophilic groups into the first electrolyte layer, the van der Waals forces between the hydrophilic groups and the sulfide can be used to strengthen the bond between the binder and the sulfide solid electrolyte. The presence of the lipophilic groups helps to inhibit the aggregation of the binder, promotes the uniform dispersion of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer, and promotes the transport of active ions in the solid electrolyte layer, thereby improving the cycle performance of the solid-state battery.

[0011] On the other hand, the improved dispersion uniformity of sulfide solid electrolyte and amphiphilic binder in the first electrolyte layer is beneficial to improving the contact network between sulfide solid electrolytes, increasing adhesion, improving the stability and mechanical strength of the first electrolyte layer and solid electrolyte layer, promoting the transport of active ions, and thus improving the cycle performance and discharge capacity of the battery.

[0012] On the other hand, the improved dispersion uniformity of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer is beneficial to improving the adhesion strength of the first electrolyte layer on the first electrode layer, which is beneficial to reducing the interfacial stability and interfacial impedance between the solid electrolyte layer and the first electrode layer, thereby improving the cycle stability and discharge capacity of the battery.

[0013] Furthermore, the first electrolyte layer can be formed by coating and drying a slurry comprising a sulfide solid electrolyte, a binder, and an organic solvent. When a low-polarity or non-polar solvent is selected as the organic solvent, the high reactivity of the sulfide solid electrolyte can easily lead to insufficient uniform dispersion of the sulfide solid electrolyte in the slurry. By introducing an amphiphilic binder with both hydrophilic and lipophilic groups into the first electrolyte layer, the good compatibility of the lipophilic groups with the solvent and the van der Waals forces between the hydrophilic groups and the sulfide can improve the uniformity of dispersion of the sulfide solid electrolyte in the slurry, thereby improving the uniformity of dispersion of the sulfide solid electrolyte in the first electrolyte layer. This further improves the cycle performance of the solid-state battery, and also improves the film strength and adhesion strength of the first electrolyte layer on the film substrate, significantly reducing the risk of film detachment.

[0014] The improvement described in any part of the context of this application is not intended to be limited to any theory.

[0015] In some embodiments, the contact angle value of the amphiphilic adhesive is 20° to 90°, and can be selected as 30° to 90°; the contact angle value is the water contact angle value of the membrane material composed of the amphiphilic adhesive, and the test temperature is 23±2℃.

[0016] In some embodiments, the contact angle of the amphiphilic adhesive is 45° to 90°, optionally 60° to 90°, and the test temperature is 23±2℃.

[0017] By selecting an amphiphilic binder with the aforementioned contact angle value, it is beneficial to promote the bonding, dispersion, and ion transport of hydrophilic and lipophilic groups, and to promote a more uniform dispersion of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer.

[0018] In some embodiments, the amphiphilic adhesive satisfies one or more of the following characteristics:

[0019] The hydrophilic group includes one or more of chlorine atom, ether bond, carboxyl group, -C(=O)-O- and amide group (optionally, the amide group may include -C(=O)-NH-);

[0020] The lipophilic group includes C 1-8 alkyl.

[0021] In some embodiments, the lipophilic group includes one or more of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl.

[0022] By selecting amphiphilic binders with the aforementioned types of hydrophilic and lipophilic groups, it is beneficial to better control the contact angle value of the amphiphilic binder, to better promote the combined gain effect of hydrophilic and lipophilic groups, to better balance the van der Waals forces between hydrophilic groups and sulfides and the inhibitory effect of lipophilic groups on binder aggregation, and to promote more uniform dispersion of sulfide solid electrolyte and amphiphilic binder in the first electrolyte layer.

[0023] In some embodiments, the amphiphilic binder includes a carbon skeleton and side groups grafted onto the carbon skeleton, the side groups including the hydrophilic group and the lipophilic group.

[0024] By selecting an amphiphilic binder with the aforementioned structure, the synergistic effect between the carbon skeleton and the hydrophilic groups grafted onto the side groups is beneficial for better encapsulation of the sulfide solid electrolyte. The lipophilic groups grafted onto the side groups can inhibit the aggregation of the binder. This structural design is beneficial for promoting a more uniform dispersion of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer.

[0025] In some embodiments, the amphiphilic adhesive comprises amphiphilic rubber.

[0026] In some embodiments, the contact angle of the amphiphilic rubber is 20° to 90°, optionally 30° to 90°, further optionally 45° to 90°, and even more preferably 60° to 90°;

[0027] The contact angle value is the water contact angle value of the membrane material composed of the amphiphilic adhesive, and the test temperature is 23±2℃.

[0028] In some embodiments, the amphiphilic rubber satisfies one or more of the following characteristics:

[0029] The elastic deformation of the amphiphilic rubber at 45°C is denoted as δ, where δ ≥ 200%.

[0030] The elastic modulus of the amphiphilic rubber at 30°C is denoted as E, where E ≤ 100 MPa.

[0031] In some embodiments, the amphiphilic rubber satisfies one or more of the following characteristics:

[0032] The elastic deformation of the amphiphilic rubber at 45°C satisfies 450% ≤ δ ≤ 600%;

[0033] The elastic modulus of the amphiphilic rubber at 30°C satisfies 50MPa≤E≤85MPa.

[0034] By introducing amphiphilic rubber with the aforementioned elastic deformation capacity and / or elastic modulus, the deformation capacity of the rubber can be used to further improve the contact between the amphiphilic binder and the sulfide solid electrolyte, thereby further improving the cycle performance of the solid-state battery.

[0035] On the other hand, improving the contact between the amphiphilic binder and the sulfide solid electrolyte is beneficial to further improving the discharge capacity of solid-state batteries.

[0036] In some embodiments, the amphiphilic rubber includes amphiphilic acrylate rubber.

[0037] In some embodiments, the amphiphilic acrylate rubber includes one or more of chlorinated acrylate rubber, active chlorinated acrylate rubber, epoxy acrylate rubber, carboxyl acrylate rubber, double bond acrylate rubber, double crosslinked acrylate rubber, and ethylene methyl acrylate rubber.

[0038] By introducing the aforementioned amphiphilic acrylate rubber, it is beneficial to better control the contact angle value of the amphiphilic binder, to better promote the combined gain effect of hydrophilic and lipophilic groups, to better balance the van der Waals forces between hydrophilic groups and sulfides and the inhibitory effect of lipophilic groups on binder aggregation, and to promote more uniform dispersion of sulfide solid electrolyte and amphiphilic binder in the first electrolyte layer.

[0039] In some embodiments, the first electrolyte layer satisfies one or more of the following characteristics:

[0040] The amphiphilic binder has a weight percentage of 0.5 wt% to 15 wt% in the first electrolyte layer;

[0041] The amphiphilic adhesive accounts for more than or equal to 10% of the weight of the first adhesive, and can be selected as 10% to 100%.

[0042] The amphiphilic adhesive includes an amphiphilic rubber, and the weight percentage of the amphiphilic rubber in the first electrolyte layer is 0.5 wt% to 15 wt%.

[0043] The amphiphilic adhesive includes amphiphilic rubber, and the weight percentage of the amphiphilic rubber in the first adhesive is greater than or equal to 10%, which can be selected as 10% to 100%.

[0044] The first adhesive further includes one or more of the following adhesives: nitrile rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, natural rubber, polyvinylidene fluoride, etherified cellulose, polymethyl methacrylate, polyethylene oxide, and methyl vinyl silicone rubber;

[0045] The thickness of the first electrolyte layer is 10 μm to 70 μm.

[0046] In some embodiments, the first electrolyte layer satisfies one or more of the following characteristics:

[0047] The weight percentage of the amphiphilic binder in the first electrolyte layer is 1 wt% to 15 wt%.

[0048] The amphiphilic adhesive accounts for 30% to 100% of the weight of the first adhesive;

[0049] The amphiphilic adhesive includes an amphiphilic rubber, and the weight percentage of the amphiphilic rubber in the first electrolyte layer is 1 wt% to 15 wt%.

[0050] The amphiphilic adhesive includes amphiphilic rubber, and the weight percentage of the amphiphilic rubber in the first adhesive is 30wt% to 100wt%.

[0051] The thickness of the first electrolyte layer is 20 μm to 50 μm.

[0052] In some embodiments, the first electrolyte layer satisfies one or more of the following characteristics:

[0053] In the first electrolyte layer, the weight ratio of the amphiphilic binder to the sulfide solid electrolyte is (2-20):100;

[0054] In the first electrolyte layer, the amphiphilic binder comprises amphiphilic rubber, and the weight ratio of the amphiphilic rubber to the sulfide solid electrolyte is (2-20):100.

[0055] In some embodiments, the first electrolyte layer satisfies one or more of the following characteristics:

[0056] In the first electrolyte layer, the weight ratio of the amphiphilic binder to the sulfide solid electrolyte is (2-18):100;

[0057] In the first electrolyte layer, the amphiphilic binder comprises amphiphilic rubber, and the weight ratio of the amphiphilic rubber to the sulfide solid electrolyte is (2-18):100.

[0058] The content of the amphiphilic binder in the first electrolyte layer can be adjusted by adjusting one or more of the following parameters: the weight percentage of the amphiphilic binder in the first electrolyte layer, the weight ratio of the amphiphilic binder in the first binder, the weight percentage of the amphiphilic rubber in the first electrolyte layer, the weight ratio of the amphiphilic rubber in the first binder, the weight ratio of the amphiphilic binder to the sulfide solid electrolyte, and the weight ratio of the amphiphilic rubber to the sulfide solid electrolyte.

[0059] By controlling one or more of the following parameters within the aforementioned ranges—the weight percentage of the amphiphilic binder in the first electrolyte layer, the weight ratio of the amphiphilic binder in the first binder, and the weight ratio of the amphiphilic binder to the sulfide solid electrolyte—it is beneficial to better achieve one or more advantages, such as improving the component dispersion uniformity of the first electrolyte layer, optimizing the electrical contact network, improving interfacial adhesion strength and interfacial stability, and reducing interfacial impedance. This is beneficial to better improve the cycle performance of solid-state batteries. At the same time, solid-state batteries also have good ion transport performance, which can take into account good battery kinetics.

[0060] By adjusting one or more of the following parameters within the aforementioned ranges—the weight percentage of amphiphilic rubber in the first binder, the weight percentage of amphiphilic rubber in the first electrolyte layer, and the weight ratio of amphiphilic rubber to the sulfide solid electrolyte—it is beneficial to improve the electrical contact network in the first electrolyte layer, thereby improving the cycle performance of the solid-state battery.

[0061] By controlling the thickness of the first electrolyte layer within the aforementioned range, it is possible to promote the better performance of the amphiphilic binder while also taking into account the ion transport performance between the first and second electrode layers, thus better controlling the influence of the binder in the first electrolyte layer on the overall resistivity of the solid electrolyte layer.

[0062] In some embodiments, the sulfide solid electrolyte includes one or more of the following: LGPS type sulfide electrolyte, silver-germanium sulfide type sulfide electrolyte, lithium sulfide-phosphorus pentasulfide complex sulfide electrolyte, and thio-LISICON sulfide electrolyte.

[0063] In some embodiments, the sulfide solid electrolyte includes Li 6-x PS 5-x Cl 1+x , where 0≤x≤0.9.

[0064] When selecting the aforementioned types of sulfide solid electrolytes, the aforementioned improvement effects can be achieved.

[0065] By doping chlorine (Cl) into sulfide solid electrolytes, chlorine (Cl) can replace a portion of sulfur (S), which helps to further reduce the release of hydrogen sulfide gas from sulfide solid electrolytes in aqueous environments.

[0066] In some embodiments, the solid electrolyte layer further includes a second electrolyte layer located between the second electrode layer and the first electrolyte layer;

[0067] The second electrolyte layer includes a solid electrolyte (which may be referred to as the second solid electrolyte) and optionally includes a second binder.

[0068] In some embodiments, the weight percentage of the amphiphilic adhesive in the second electrolyte layer is denoted as f12, and the weight percentage of the amphiphilic adhesive in the first electrolyte layer is denoted as f11;

[0069] The second electrolyte layer satisfies one or more of the following characteristics:

[0070] 0≤f12 <f11;

[0071] The weight percentage f12 of the amphiphilic binder in the second electrolyte layer is 0 wt% to 5 wt%.

[0072] In some embodiments, the solid-state battery satisfies one or more of the following characteristics:

[0073] The total thickness of the solid electrolyte layer is greater than 15 μm, and can be selected from 30 μm to 110 μm, and further selected from 40 μm to 90 μm;

[0074] The thickness of the second electrolyte layer is greater than or equal to 10 μm, and can be selected as 20 μm to 45 μm, and more preferably 30 μm to 40 μm;

[0075] The thickness of the second electrolyte layer is greater than the thickness of the first electrolyte layer;

[0076] The binder content in the second electrolyte layer is lower than that in the first electrolyte layer, by weight percentage;

[0077] The second adhesive has a weight percentage of 0 wt% to 5 wt% in the second electrolyte layer;

[0078] The solid electrolyte in the second electrolyte layer accounts for 95 wt% to 100 wt% of the total weight of the second electrolyte layer.

[0079] By controlling the thickness of the solid electrolyte layer and / or the second electrolyte layer as described above, it is beneficial to reduce the risk of short circuits and improve the reliability of solid-state batteries.

[0080] By incorporating a solid electrolyte layer that simultaneously includes a first electrolyte layer and a second electrolyte layer, the first electrolyte layer improves the cycle performance of the solid-state battery while simultaneously reducing its thickness within a given total thickness. This allows for better control over the influence of the binder in the first electrolyte layer on the overall resistivity of the solid electrolyte layer. Furthermore, by controlling the second electrolyte layer to have a lower binder content and / or a higher solid electrolyte content, the solid electrolyte layer can simultaneously improve the adhesion strength between the first electrolyte layer and the first electrode layer while fully utilizing the fast ion transport capabilities of the second electrolyte layer.

[0081] By controlling the binder content in the second electrolyte layer to be lower than that in the first electrolyte layer, the second electrolyte layer can provide higher ionic conductivity, allowing the solid electrolyte layer to both improve the adhesion strength between the first electrolyte layer and the first electrode layer and fully utilize the fast ion transport properties of the second electrolyte layer.

[0082] By controlling the thickness of the second electrolyte layer to be greater than that of the first electrolyte layer, the solid electrolyte layer can simultaneously improve the adhesion strength between the first electrolyte layer and the first electrode layer and fully utilize the fast ion transport properties of the second electrolyte layer.

[0083] In some embodiments, the solid-state battery satisfies one or more of the following characteristics:

[0084] The first electrode layer is a negative electrode layer, and the second electrode layer is a positive electrode layer; optionally, the negative electrode layer includes a negative electrode current collector and a negative electrode active material layer located on at least one side of the negative electrode current collector, and the first electrolyte layer is located on the side of the negative electrode active material layer away from the negative electrode current collector;

[0085] The solid-state battery is an all-solid-state battery.

[0086] By placing the first electrolyte layer on one side of the negative electrode layer, it is beneficial to improve the adhesion and interface stability between the negative electrode layer and the solid electrolyte layer, reduce the interface impedance between the negative electrode layer and the solid electrolyte layer, and thus improve the cycle performance of the solid-state battery.

[0087] In a second aspect of this application, a solid electrolyte membrane is provided, which includes a first electrolyte layer as defined in the first aspect of this application.

[0088] The solid electrolyte membrane includes a first electrolyte layer as defined in the first aspect of this application. The first electrolyte layer includes a sulfide solid electrolyte and an amphiphilic binder. By introducing an amphiphilic binder having both hydrophilic and lipophilic groups into the first electrolyte layer, the van der Waals forces between the hydrophilic groups and the sulfide can strengthen the bond between the binder and the sulfide solid electrolyte. The presence of the lipophilic groups helps to inhibit the aggregation of the binder, promotes the uniform dispersion of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer, and promotes the transport of active ions in the solid electrolyte layer, thereby improving the cycle performance of the solid-state battery including the solid electrolyte membrane.

[0089] On the other hand, the improved dispersion uniformity of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer is beneficial to improving the contact network between the sulfide solid electrolytes, increasing the adhesion, improving the stability and mechanical strength of the first electrolyte layer and the solid electrolyte membrane, promoting the transport of active ions, and thus improving the cycle performance and discharge capacity of the solid battery including the solid electrolyte membrane.

[0090] On the other hand, the improved dispersion uniformity of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer is beneficial to improving the adhesion strength of the first electrolyte layer on the first electrode layer, which is beneficial to reducing the interfacial stability and interfacial impedance between the solid electrolyte membrane and the adjacent electrode layer, thereby improving the cycle stability and discharge capacity of the solid battery including the solid electrolyte membrane.

[0091] Furthermore, the first electrolyte layer can be formed by coating and drying a slurry comprising a sulfide solid electrolyte, a binder, and an organic solvent. When a low-polarity or non-polar solvent is selected as the organic solvent, the high reactivity of the sulfide solid electrolyte can easily lead to insufficient uniform dispersion of the sulfide solid electrolyte in the slurry. By introducing an amphiphilic binder with both hydrophilic and lipophilic groups into the first electrolyte layer, the good compatibility of the lipophilic groups with the solvent and the van der Waals forces between the hydrophilic groups and the sulfide can improve the uniformity of dispersion of the sulfide solid electrolyte in the slurry, thereby improving the uniformity of dispersion of the sulfide solid electrolyte in the first electrolyte layer. This further improves the cycle performance of the solid-state battery including the solid electrolyte membrane, and further improves the film strength and adhesion strength of the first electrolyte layer on the film substrate, significantly reducing the risk of film detachment.

[0092] In a third aspect of this application, an electrolyte electrode is provided, comprising an electrode body and a first electrolyte layer as defined in the first aspect of this application, the first electrolyte layer being located on at least one side of the electrode body.

[0093] The electrolyte electrode includes an electrode body and a first electrolyte layer located on at least one side of the electrode body. As mentioned above, by utilizing the amphiphilic properties of the amphiphilic binder in the first electrolyte layer, the sulfide solid electrolyte and the amphiphilic binder can be uniformly dispersed in the first electrolyte layer, thereby improving the cycle performance of the solid-state battery including the electrolyte electrode.

[0094] On the other hand, the introduction of amphiphilic binders facilitates the contact network between sulfide solid electrolytes, thereby improving the cycle performance and discharge capacity of solid-state batteries including the electrolyte electrode.

[0095] On the other hand, the introduction of amphiphilic binders is beneficial to improving the adhesion strength of the first electrolyte layer on the electrode body, which helps to reduce the interfacial stability and interfacial impedance between the solid electrolyte membrane and the electrode body, thereby improving the cycle stability and discharge capacity of the solid-state battery including the electrolyte electrode.

[0096] The first electrolyte layer in the electrolyte electrode can also be formed by coating and drying a slurry comprising a sulfide solid electrolyte, a binder, and an organic solvent. As mentioned earlier, by utilizing the amphiphilic properties of the amphiphilic binder in the first electrolyte layer, the dispersion uniformity of the sulfide solid electrolyte in the slurry can be improved, thereby improving the dispersion uniformity of the sulfide solid electrolyte in the first electrolyte layer, and further improving the cycle performance of the solid-state battery including the electrolyte electrode.

[0097] In some embodiments, the electrolyte electrode sheet is an electrolyte negative electrode sheet, and the electrode body is a negative electrode body.

[0098] The electrolyte electrode can be selected as the electrolyte negative electrode. In this case, the first electrolyte layer can be placed on the side of the negative electrode layer in the solid-state battery. This is beneficial to improve the adhesion between the negative electrode layer and the solid electrolyte layer, reduce the interfacial impedance between the negative electrode layer and the solid electrolyte layer, and thus improve the cycle performance of the solid-state battery.

[0099] In some embodiments, the negative electrode body includes a negative electrode current collector and a negative electrode active material layer located on at least one side of the negative electrode current collector, wherein the first electrolyte layer is located on the side of the negative electrode active material layer away from the negative electrode current collector;

[0100] The negative electrode active material layer satisfies one or more of the following characteristics:

[0101] The negative electrode active material layer includes a negative electrode binder;

[0102] The negative electrode active material layer includes a negative electrode active substance, which includes a silicon-based material.

[0103] In some embodiments where the negative electrode active material layer includes a negative electrode binder, the amphiphilic binder in the first electrolyte layer helps to improve the connection between the first electrolyte layer and the negative electrode active material layer, thereby increasing the adhesion strength between the first electrolyte layer and the negative electrode layer.

[0104] In some embodiments where the negative electrode active material layer includes a silicon-based material, the introduction of an amphiphilic binder in the first electrolyte layer is beneficial to improving the interfacial contact stability between the first electrolyte layer and the negative electrode layer when the silicon-based material undergoes volume expansion or contraction, which is beneficial to achieving better cycle performance.

[0105] In some embodiments of the fourth aspect of this application, a method for preparing a solid-state battery is provided, comprising the following steps:

[0106] An electrolyte electrode sheet is prepared; wherein the electrolyte electrode sheet includes a first electrode layer and a first electrolyte layer located on at least one side of the first electrode layer; the first electrolyte layer includes a sulfide solid electrolyte and an amphiphilic binder, wherein the amphiphilic binder includes hydrophilic groups and lipophilic groups;

[0107] A second electrode layer is formed on the side of the first electrolyte layer away from the first electrode layer.

[0108] The solid-state battery prepared includes the advantages of the aforementioned solid-state batteries.

[0109] In some embodiments, the first electrolyte layer is formed on at least one side of the first electrode layer by coating and drying an electrolyte slurry;

[0110] The electrolyte slurry comprises a solid electrolyte, the amphiphilic binder, and an organic solvent; the solid electrolyte comprises a sulfide solid electrolyte.

[0111] In some embodiments, the electrolyte electrode is prepared by a method comprising the following steps:

[0112] The electrolyte slurry is coated onto at least one side surface of the first electrode sheet and dried to prepare the electrolyte electrode sheet; wherein the first electrode sheet forms the first electrode layer, and the dried electrolyte slurry forms the first electrolyte layer.

[0113] When the first electrolyte layer is formed by wet process using electrolyte slurry, an amphiphilic binder with both hydrophilic and lipophilic groups can be introduced into the first electrolyte layer. The good compatibility of the lipophilic groups with the solvent and the van der Waals forces between the hydrophilic groups and the sulfide can improve the dispersion uniformity of the sulfide solid electrolyte in the slurry, thereby improving the dispersion uniformity of the sulfide solid electrolyte in the first electrolyte layer, and further improving the cycle performance of the solid battery.

[0114] In some embodiments, the electrolyte electrode is an electrolyte negative electrode, and the method for preparing the solid-state battery includes the following steps:

[0115] The electrolyte slurry is coated onto at least one surface of the negative electrode sheet and dried to prepare the electrolyte negative electrode sheet; wherein the negative electrode sheet forms a negative electrode layer, and the dried electrolyte slurry forms the first electrolyte layer;

[0116] A second electrolyte layer and a positive electrode layer are formed sequentially on the side of the first electrolyte layer away from the negative electrode layer.

[0117] In some embodiments, the dielectric constant ε of the organic solvent in the electrolyte slurry satisfies: ε≤6.5.

[0118] In some embodiments, the organic solvent in the electrolyte slurry satisfies one or more of the following characteristics:

[0119] The organic solvent includes one or more of low-polarity solvents and non-polar solvents; wherein, the dielectric constant ε1 of the low-polarity solvent satisfies: 2.6 < ε1 ≤ 6.5; and the dielectric constant ε2 of the non-polar solvent satisfies: ε2 ≤ 2.6.

[0120] The organic solvent includes substituted benzene, wherein the phenyl group in the substituted benzene is replaced by one or more substituents selected from the substituent group G, the substituent group G including: methyl, chlorine atom and methoxy;

[0121] The organic solvent with a dielectric constant less than or equal to 6.5 is present in a weight percentage of 50 wt% to 100 wt%, optionally 70 wt% to 100 wt%.

[0122] The organic solvent includes one or more of xylene, butyl butyrate, octyl butyrate, thallium, chlorobenzene, dimethyl carbonate, ethyl acetate, n-hexane, anisole, dibromomethane, triethyl phosphate, isopropyl ether, and benzyl acetate; optionally, the organic solvent includes one or more of p-xylene, pseudotrimethylbenzene, butyl butyrate (butyl butyrate may include one or more of n-butyl butyrate, isobutyl isobutyrate, etc.), and octyl butyrate;

[0123] The organic solvent in the electrolyte slurry is 30 wt% to 90 wt% by weight; optionally, the organic solvent in the electrolyte slurry is 40 wt% to 70 wt% by weight.

[0124] The amphiphilic binder is present in the electrolyte slurry at a weight percentage of 0.5 wt% to 6 wt%, and may be 1 wt% to 6 wt%.

[0125] For electrolyte slurry systems containing the aforementioned organic solvents, selecting low-polarity or non-polar solvents can reduce side reactions with the highly reactive sulfide solid electrolyte. Furthermore, by introducing an amphiphilic binder with both hydrophilic and lipophilic groups into the first electrolyte layer, the good compatibility of the lipophilic groups with the aforementioned organic solvents and the van der Waals forces between the hydrophilic groups and the sulfides can improve the dispersion uniformity of the sulfide solid electrolyte in the electrolyte slurry system, thereby improving the dispersion uniformity of the sulfide solid electrolyte in the first electrolyte layer, and further improving the cycle performance of the solid-state battery.

[0126] In some embodiments, the method for preparing the solid-state battery satisfies one or more of the following characteristics:

[0127] The electrolyte electrode sheet is the electrolyte electrode sheet described in the third aspect of this application, and the first electrode layer includes a corresponding electrode body;

[0128] The solid-state battery prepared is the solid-state battery described in the first aspect of this application.

[0129] In a fifth aspect of this application, an electrical device is provided, comprising at least one of the solid-state battery described in the first aspect of this application, the solid electrolyte membrane described in the second aspect of this application, the electrolyte electrode described in the third aspect of this application, and a solid-state battery prepared by the method for preparing a solid-state battery described in the fourth aspect of this application.

[0130] Details of one or more embodiments or examples of this application are set forth in the following drawings and description. Other features, objects, and advantages of this application will become apparent from the specification, drawings, and claims. Attached Figure Description

[0131] To better describe and illustrate the embodiments, examples, or models provided in this application, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, the currently described embodiments, examples, or models, or the best mode of these applications as currently understood. It should also be noted that the drawings are drawn in a simplified form and are only used to facilitate and clarify the illustration of this application. The various dimensions of each component shown in the drawings are arbitrarily shown and may be precise or not drawn to scale. For example, the dimensions of components are appropriately exaggerated in some places in the drawings to make the illustration clearer. Unless otherwise specified, the components in the drawings are not drawn to scale. The drawings of this application do not limit every dimension of every component. Furthermore, the same reference numerals are used to denote the same components throughout all the drawings. In the drawings:

[0132] Figure 1 is a schematic diagram of the structure of an electrolyte electrode sheet according to an embodiment of this application. The electrolyte electrode sheet includes an electrode body and a first electrolyte layer.

[0133] Figure 2 is a schematic diagram of the structure of an electrolyte electrode sheet according to an embodiment of the present application. The electrolyte electrode sheet includes an electrode body and a first electrolyte layer. The electrode body includes a current collector and an electrode active material layer. The electrode active material layer is located between the current collector and the first electrolyte layer. The electrolyte electrode sheet includes a current collector and an electrode active material layer and a first electrolyte layer sequentially disposed on one side of the current collector.

[0134] Figure 3 is a schematic diagram of the structure of an electrolyte negative electrode sheet according to an embodiment of the present application. The electrolyte negative electrode sheet includes a negative electrode body and a first electrolyte layer.

[0135] Figure 4 is a schematic diagram of the structure of an electrolyte negative electrode sheet according to an embodiment of this application. The electrolyte negative electrode sheet includes a negative electrode layer and a first electrolyte layer.

[0136] Figure 5 is a schematic diagram of the structure of an electrolyte negative electrode sheet according to an embodiment of the present application. The electrolyte negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer and a first electrolyte layer sequentially disposed on one side of the negative electrode current collector; wherein, the negative electrode current collector and the negative electrode active material layer are contained in the negative electrode body or contained in the negative electrode layer.

[0137] Figure 6 is a schematic diagram of the structure of a solid-state battery cell according to an embodiment of this application. The solid-state battery cell includes a first electrode layer, a solid electrolyte layer and a second electrode layer stacked in sequence.

[0138] Figure 7 is a schematic diagram of the structure of a solid-state battery cell according to an embodiment of the present application. The solid-state battery cell includes a first electrode layer, a solid electrolyte layer and a second electrode layer stacked in sequence. The solid electrolyte layer includes a first electrolyte layer, which is located on the side close to the first electrode layer.

[0139] Figure 8 is a schematic diagram of the structure of a solid-state battery cell according to an embodiment of this application. The solid-state battery cell includes a first electrode layer, a first electrolyte layer, a second electrolyte layer, and a second electrode layer stacked sequentially.

[0140] Figure 9 is a schematic diagram of the structure of a solid-state battery cell according to an embodiment of this application. The solid-state battery cell includes a negative electrode layer, a solid electrolyte layer and a positive electrode layer stacked in sequence.

[0141] Figure 10 is a schematic diagram of the structure of a solid-state battery cell according to an embodiment of the present application. The solid-state battery cell includes a negative electrode layer, a first electrolyte layer, a second electrolyte layer and a positive electrode layer stacked in sequence, wherein the first electrolyte layer and the second electrolyte layer constitute a solid electrolyte layer.

[0142] Figure 11 is a schematic diagram of a solid-state battery cell according to an embodiment of this application.

[0143] Figure 12 is an exploded view of a solid-state battery cell according to an embodiment of this application, as shown in Figure 11.

[0144] Figure 13 is a schematic diagram of a battery device according to an embodiment of this application.

[0145] Figure 14 is a schematic diagram of a battery pack according to one embodiment of this application.

[0146] Figure 15 is an exploded view of a battery pack according to an embodiment of this application, as shown in Figure 14.

[0147] Figure 16 is a schematic diagram of an electrical device using a solid-state battery as a power source according to an embodiment of this application.

[0148] Explanation of reference numerals in the attached drawings: 310, first electrolyte layer; 93, electrolyte electrode sheet; 901, electrode body; 910, current collector; 920, electrode active material layer; 13, electrolyte negative electrode sheet; 101, negative electrode body; 110, negative electrode current collector; 120, negative electrode active material layer; 10, first electrode layer; 320, second electrolyte layer; 20, second electrode layer; 100, negative electrode layer; 300, solid electrolyte layer; 200, positive electrode layer; 1, battery pack; 2, upper casing; 3, lower casing; 4, battery assembly; 5, solid-state battery cell; 51, casing; 52, solid-state battery cell; 53, cover plate; 6, power-consuming device. Detailed Implementation

[0149] The following describes in detail, with appropriate reference to the accompanying drawings, some embodiments of the solid-state battery and its preparation method, solid electrolyte membrane, electrolyte electrode, and electrical device provided in this application. However, some unnecessary details 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.

[0150] The "range" disclosed in this application can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints. Any endpoint can be included or excluded independently and can be combined arbitrarily; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0" and "5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when describing a parameter as an integer ≥ 2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 for that parameter. For instance, when describing a parameter as an integer selected from "2-10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0151] In this application, unless otherwise specified, "about" means within a reasonable range above and below the stated number, and the range of fluctuation may vary depending on the type and value of the stated number. For example, a range of ±10%, ±5%, ±2%, ±1%, etc., may be allowed. For example, taking "about 20°C" and its approximation as ±1°C, approximate values ​​such as 19°C, 19.5°C, etc., within the approximation range indicated by "about 20°C" should also be included in the range indicated by "about 20°C".

[0152] In this application, the terms "multiple," "various," "multiple items," "several," etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more (greater than or equal to) two. It can be understood that when "any number of" items are involved, it refers to any suitable combination of multiple items, that is, a combination of "any number of" items in a manner that does not conflict and enables the implementation of this application.

[0153] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0154] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. The term "implementation" as used herein has a similar understanding.

[0155] Those skilled in the art will understand that the order in which the steps are written in the various implementations or embodiments does not imply a strict execution order and does not constitute any limitation on the implementation process. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps in this application may be performed sequentially or randomly, but are preferably performed sequentially. For example, if method M includes steps (a) and (b), it means that method M may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. As another example, method M may also include step (c), meaning that step (c) can be added to method M in any order. For example, method M may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0156] In this application, open-ended technical features or solutions described using terms such as "containing," "including," or "comprising" do not exclude additional members beyond those listed unless otherwise specified. They can be considered as providing both closed-ended features or solutions comprised of the listed members and open-ended features or solutions that include additional members beyond the listed members. For example, if A includes a1, a2, and a3, it may also include other members or exclude additional members unless otherwise specified. This can be considered as providing both features or solutions where "A consists of a1, a2, and a3" or "A is selected from a1, a2, and a3," and features or solutions where "A includes not only a1, a2, and a3, but also other members."

[0157] In this application, unless otherwise stated, A (e.g., B) means that B is a non-limiting example of A, and it is understood that A is not limited to B.

[0158] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it is selected from either "with" or "without." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "option" is independent. Unless otherwise specified, the descriptions such as "optionally include" and "optionally contain" in this application, taking "optionally include" as an example, mean "may include or not include."

[0159] In this application, unless otherwise specified, the features or solutions corresponding to "and / or" include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "A and / or B" represents a group consisting of A, B, and "a combination of A and B". "Containing A and / or B" can mean "containing A, containing B, and containing A and B", or "containing A, containing B, or containing A and B", and can be appropriately understood according to the context.

[0160] The terms “combinations of,” “any combination of,” and “any combination of” used in this article include all suitable combinations of any two or more of the listed items.

[0161] In this document, the term "suitable" as used in "suitable combination", "suitable method", "any suitable method", etc., refers to the technical solution that enables the implementation of this application.

[0162] In this document, terms such as "preferred," "better," "more suitable," "ideal," "good," and "superior" are merely descriptions of more effective implementation methods or embodiments, and should be understood not to limit the scope of protection of this application. If multiple "preferred" terms appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "preferred" term shall be independent.

[0163] In this application, terms such as "further," "even more," "especially," "for example," "as," "example," and "exemplary" are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0164] In this application, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0165] In this application, the term "room temperature" generally refers to 4℃ to 35℃, and may refer to 20℃ ± 5℃. In some embodiments of this application, room temperature refers to 20℃ to 30℃.

[0166] In this application, if the unit for a data range is only followed by the right endpoint, it indicates that the units for the left and right endpoints are the same. For example, 3~5h or 3-5h both mean that the unit for the left endpoint "3" and the right endpoint "5" is h (hours), and both have the same meaning as 3h~5h. Furthermore, similar descriptions of other parameters such as temperature and size are interpreted in the same way.

[0167] In this application, "wt%" means weight percentage or mass percentage.

[0168] In this application, "greater than or equal to" and "≥" have the same meaning and can be used interchangeably; "less than or equal to" and "≤" have the same meaning and can be used interchangeably; "greater than" can be equivalently represented as ">", and "less than" can be equivalently represented as "<". In this application, unless otherwise specified, "greater than or equal to" and "≥" can be considered as providing two additional solutions: "greater than" and "equal to". In this application, unless otherwise specified, "less than or equal to" and "≤" can be considered as providing two additional solutions: "less than" and "equal to".

[0169] In this application, the exemplary descriptions such as "in some implementations (or embodiments)" and "in one implementation (or embodiment)" may cover, but are not limited to, the following meanings: these solutions can be combined with other solutions in a suitable manner to form new technical solutions.

[0170] Unless otherwise specified, the term "solid-state battery" in this application refers to a battery in which the electrolyte includes a solid electrolyte. Typically, a solid-state battery includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. During charging and discharging, active ions repeatedly insert and extract between the positive and negative electrode layers. The solid electrolyte layer acts as a conductor of ions between the positive and negative electrode layers and also isolates them, preventing short circuits. Therefore, solid-state batteries do not require the separator found in traditional lithium-ion batteries. The introduction of a non-flammable solid electrolyte in solid-state batteries, replacing the organic electrolyte in traditional liquid lithium-ion batteries, significantly improves battery safety. In addition to enhanced safety, solid-state batteries are better suited for high-energy-density positive and negative electrode materials and reduce system weight, thus facilitating improvements in energy density.

[0171] In this application, unless otherwise specified, "solid electrolyte" refers to an electrolyte material or substance that exists in solid form during the storage and fabrication of solid-state batteries and their components, as well as during the operation of solid-state batteries. This includes, but is not limited to, solid electrolytes existing in solid form at room temperature.

[0172] In this application, unless otherwise specified, the electrode layer can be a positive electrode layer or a negative electrode layer, and the electrode layer includes electrode active materials. The electrode active materials can be positive electrode active materials or negative electrode active materials. The electrode active materials can be particulate matter themselves or contained within electrode active particles. The electrode active particles can be positive electrode active particles or negative electrode active particles. "Electrode active material" in the electrode layer refers to a material capable of reversibly inserting and extracting active ions. Unless otherwise specified, "negative electrode active material" refers to a material used in the negative electrode layer capable of reversibly inserting and extracting active ions; "positive electrode active material" refers to a material used in the positive electrode layer capable of reversibly extracting and inserting active ions. When the solid-state battery is charged, active ions are extracted from the positive electrode, pass through the solid electrolyte layer, and insert into the negative electrode; while when the solid-state battery is discharged, active ions are extracted from the negative electrode and insert into the positive electrode. The active ions are not particularly limited or restrictive; they can be lithium ions, corresponding to a lithium-ion solid-state battery.

[0173] In this application, "electrode active particles" refers to particles containing electrode active substances.

[0174] In this application, unless otherwise specified, "electrode active material layer" includes at least one of the positive electrode active material layer in the positive electrode layer and the negative electrode active material layer in the negative electrode layer. Depending on the specific circumstances, the electrode active material layer may refer to either the positive electrode active material layer or the negative electrode active material layer. It is understood that the positive electrode active material layer contains a positive electrode active substance, and the negative electrode active material layer contains a negative electrode active substance. In this application, "electrode active material layer" may also be abbreviated as "active material layer".

[0175] In solid-state batteries, the interfacial contact characteristics within the solid electrolyte layer and between it and adjacent electrode layers affect the battery's cycle performance. Among numerous solid electrolyte materials, sulfide solid electrolytes stand out due to their ultra-high ionic conductivity (e.g., up to approximately 10⁻⁶). -3 ~10 -2 With its excellent mechanical properties, such as good flexibility, it possesses superior ion-conducting ability and good deformation capability, making it one of the most promising solid electrolyte materials for practical application and industrialization. When preparing solid electrolyte membranes using a wet process, an electrolyte slurry comprising a sulfide solid electrolyte, a binder, and an organic solvent can be used. This slurry is then coated and dried to form a membrane layer comprising the sulfide solid electrolyte and the binder. Due to the high reactivity of the sulfide solid electrolyte, choosing a low-polarity or non-polar organic solvent helps reduce side reactions. However, this can easily lead to insufficient uniform dispersion of the sulfide solid electrolyte in the electrolyte slurry, which in turn affects the uniformity of dispersion of the sulfide solid electrolyte and binder in the formed solid electrolyte membrane. This may result in one or more problems, such as local differences in ionic conductivity, poor local interfacial contact, and unstable ion transport performance, further affecting the improved cycle performance of solid-state batteries containing this solid electrolyte membrane. When the electrode active material layer of the electrode sheet is used as the coating substrate for the electrolyte slurry, poor dispersion of the sulfide solid electrolyte in the electrolyte slurry may affect the film strength of the formed solid electrolyte film, the adhesion strength between the solid electrolyte film and the substrate, as well as the interface stability and interface impedance, which may in turn affect the cycle stability and discharge capacity of the solid-state battery. Poor film strength of the solid electrolyte film may also lead to the risk of film detachment.

[0176] Based on this, according to various embodiments and examples of this application, this application provides a solid-state battery and its preparation method, a solid electrolyte membrane, an electrolyte electrode, and an electrical device. This solid-state battery exhibits improved cycle performance.

[0177] In some embodiments of the first aspect of this application, a solid-state battery is provided, which includes a first electrode layer, a solid electrolyte layer and a second electrode layer stacked sequentially; wherein, the solid electrolyte layer includes a first electrolyte layer, and the first electrolyte layer is located on the side of the solid electrolyte layer close to the first electrode layer;

[0178] The first electrolyte layer comprises a sulfide solid electrolyte and a first binder, wherein the first binder comprises an amphiphilic binder.

[0179] In some embodiments, the amphiphilic adhesive includes both hydrophilic and lipophilic groups.

[0180] In some embodiments, this application provides a solid-state battery, which includes a first electrode layer, a solid electrolyte layer, and a second electrode layer stacked sequentially; wherein the solid electrolyte layer includes a first electrolyte layer, and the first electrolyte layer is located on the side of the solid electrolyte layer close to the first electrode layer;

[0181] The first electrolyte layer includes a first solid electrolyte and a first binder. The first solid electrolyte includes a sulfide solid electrolyte, and the first binder includes an amphiphilic binder, which includes hydrophilic groups and lipophilic groups.

[0182] The aforementioned solid-state battery has a first electrolyte layer comprising a sulfide solid electrolyte and a binder (which may be referred to as the first binder) disposed on the side of the solid electrolyte layer near the first electrode layer. By introducing an amphiphilic binder having both hydrophilic and lipophilic groups into the first electrolyte layer, the van der Waals forces between the hydrophilic groups and the sulfide can be used to strengthen the bond between the binder and the sulfide solid electrolyte. The presence of the lipophilic groups helps to inhibit the aggregation of the binder, promotes the uniform dispersion of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer, and promotes the transport of active ions in the solid electrolyte layer, thereby improving the cycle performance of the solid-state battery.

[0183] On the other hand, the improved dispersion uniformity of sulfide solid electrolyte and amphiphilic binder in the first electrolyte layer is beneficial to improving the contact network between sulfide solid electrolytes, increasing adhesion, improving the stability and mechanical strength of the first electrolyte layer and solid electrolyte layer, promoting the transport of active ions, and thus improving the cycle performance and discharge capacity of the battery.

[0184] On the other hand, the improved dispersion uniformity of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer is also beneficial to improving the adhesion strength of the first electrolyte layer on the first electrode layer, which helps to reduce the interfacial stability and interfacial impedance between the solid electrolyte layer and the first electrode layer, and thus can also improve the cycle stability and discharge capacity of the battery.

[0185] Furthermore, the first electrolyte layer can be formed by coating and drying a slurry comprising a sulfide solid electrolyte, a binder, and an organic solvent. When a low-polarity or non-polar solvent is selected as the organic solvent, the high reactivity of the sulfide solid electrolyte can easily lead to insufficient uniform dispersion of the sulfide solid electrolyte in the slurry. By introducing an amphiphilic binder with both hydrophilic and lipophilic groups into the first electrolyte layer, the good compatibility of the lipophilic groups with the solvent and the van der Waals forces between the hydrophilic groups and the sulfide can be utilized to further improve the uniformity of dispersion of the sulfide solid electrolyte in the slurry, thereby improving the uniformity of dispersion of the sulfide solid electrolyte in the first electrolyte layer. This can further improve the cycle performance of the solid-state battery, and further improve the film strength and adhesion strength of the first electrolyte layer on the film substrate, significantly reducing the risk of film detachment.

[0186] The improvement described in any part of the context of this application is not intended to be limited to any theory.

[0187] In this application, unless otherwise specified, "amphiphilic adhesive" refers to a polymer comprising both hydrophilic and lipophilic groups. Amphiphilic adhesives possess both hydrophilic and lipophilic properties. The "amphiphilicity" of the amphiphilic adhesive can be characterized using the "contact angle value." Unless otherwise specified, the "contact angle value" of the amphiphilic adhesive refers to the water contact angle value of the membrane material formed by the amphiphilic adhesive. The amphiphilic adhesive solution can be coated and dried to form a film. The water contact angle value of the membrane material can be determined using conventional water contact angle testing methods. For example, a water droplet can be placed on the membrane surface, and the contact angle formed between the water droplet and the membrane surface can be observed and measured: a side view of the droplet is captured under an optical microscope, the droplet shape is analyzed using geometric principles, and the obtained contact angle value is recorded. "Amphiphilic adhesive solution" refers to a mixture of an amphiphilic adhesive and an organic solvent, obtained by dissolving the amphiphilic adhesive in an organic solvent. This organic solvent can be a low-polarity or non-polar solvent (e.g., with a dielectric constant less than or equal to 6.5). The mass concentration of the amphiphilic adhesive in the solution can be 2% to 10% (e.g., 2%, 4%, 5%, 6%, 8%, 10%, etc., by mass percentage). The testing temperature is in the range of 20℃ to 30℃, for example, 23±2℃. A larger contact angle value indicates better hydrophilicity, and conversely, a smaller contact angle value indicates better oleophilicity or hydrophobicity. For example, p-xylene can be used as a solvent for ethylene methyl acrylate rubber, but it is not limited to this.

[0188] In this application, the test temperature for the contact angle is taken as "the contact angle value of the amphiphilic adhesive is 20°~90° at 23±2℃". As long as a temperature exists within the range of 23±2℃, the measured contact angle value of the amphiphilic adhesive is within the range of 20°~90°. "23±2℃" means that the temperature can be controlled at any temperature condition between 21℃ and 25℃.

[0189] Non-limitingly, the contact angle value of the amphiphilic adhesive can be 20° to 90°, optionally 30° to 90°, further optionally 45° to 90°, even further optionally 60° to 90°, and even further preferably, the contact angle value of the amphiphilic adhesive is less than 90°. Non-limitingly, the measuring temperature can refer to the preceding text, for example, it can be 23±2℃, such as 21°, 22°, 23°, 24°, 25°, etc.

[0190] In some implementations, the contact angle of the amphiphilic adhesive is less than 90° at a measurement temperature of 23±2°C.

[0191] In this application, the polarity of a solvent can be reflected by its dielectric constant. Generally, a larger dielectric constant indicates greater polarity, and vice versa. In this application, the dielectric constant of a low-polarity solvent is denoted as ε1, and unless otherwise specified, 2.6 < ε1 ≤ 6.5. The dielectric constant of a non-polar solvent is denoted as ε2, and unless otherwise specified, ε2 ≤ 2.6. In this application, unless otherwise specified, the dielectric constant of a solvent can be obtained from chemical handbooks or existing literature, or by testing using conventional methods in the art.

[0192] Typically, examples of "nonpolar solvent" and "low polar solvent" in this application may include, but are not limited to, one or more of p-xylene, pseudotrimethylbenzene, toluene, n-hexane, n-butyl butyrate, isobutyl isobutyrate, octyl butyrate, chlorobenzene, dimethyl carbonate, anisole, dibromomethane, triethyl phosphate, isopropyl ether, benzyl acetate, etc.

[0193] In some embodiments, the adhesive solution for preparing the amphiphilic adhesive may be one or more of the following solvents: p-xylene, pseudotrimethylbenzene, n-butyl butyrate, isobutyl isobutyrate, octyl butyrate, etc.

[0194] Those skilled in the art can identify the types and structures of components in solid-state batteries using one or more of the following detection methods, including but not limited to: Fourier transform infrared (FT-IR) spectroscopy, ultraviolet spectroscopy, and proton nuclear magnetic resonance (NMR) spectroscopy. 1Methods include 1H NMR, X-ray diffraction (XRD), gel permeation chromatography (GPC), high-performance liquid chromatography (HPLC), mass spectrometry, inductively coupled plasma atomic emission spectrometry (ICP), and energy dispersive spectroscopy (EDS). Non-limitingly, one or more of the following methods can be used to analyze the type, structure, and molecular weight of the binder components in solid-state batteries: Fourier transform infrared (FT-IR) spectroscopy, ultraviolet spectroscopy, and proton nuclear magnetic resonance (NMR) spectroscopy. 1 Methods include 1H NMR, gel permeation chromatography (GPC), high performance liquid chromatography (HPLC), mass spectrometry, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The sample preparation and testing methods for these methods are known to those skilled in the art, and the test parameters can be appropriately adjusted according to the sample characteristics.

[0195] In this application, unless otherwise specified, one of the first electrode layer and the second electrode layer in the solid-state battery is the positive electrode layer and the other is the negative electrode layer.

[0196] Non-limitingly, the contact angle value of the amphiphilic adhesive and any example thereof (such as amphiphilic rubber, further such as amphiphilic acrylic rubber) may also be any of the following values, or greater than or equal to any of the following values ​​and less than 90°, or greater than any of the following values ​​and less than 90°, or selected from a range consisting of any two of the following values: 20°, 22°, 24°, 25°, 26°, 28°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 86°, 87°, 88°, 89°, 90°, etc., and the test temperature may be defined in the context, for example, 23±2℃. The contact angle values ​​of amphiphilic adhesives and any examples thereof (such as amphiphilic rubbers, and further, amphiphilic acrylic rubbers) may also be selected from any of the following ranges: 20°–90°, 30°–90°, 40°–90°, 45°–90°, 50°–90°, 60°–90°, 70°–90°, 80°–90°, 40°–85°, 20°–90° (including the left endpoint but excluding 90°), 30°–90° (including the left endpoint but excluding 90°), 40°–90° (including the left endpoint but excluding 90°), 45°–90° (including the left endpoint but excluding 90°), 50°–90° (including the left endpoint but excluding 90°), 60°–90° (including the left endpoint but excluding 90°), 70°–90° (including the left endpoint but excluding 90°), etc. The test temperature may be referred to the context definition, for example, 23±2℃.

[0197] By selecting an amphiphilic binder with the aforementioned contact angle value, it is beneficial to promote the bonding, dispersion, and ion transport of hydrophilic and lipophilic groups, and to promote a more uniform dispersion of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer.

[0198] Without limitation, the hydrophilic group in the amphiphilic adhesive may include, but is not limited to, one or more of the following: chlorine atom, ether bond, carboxyl group, -C(=O)-O-, amide group, etc. The amide group may include -C(=O)-NH-, and further, the amide group may be -C(=O)-NH-.

[0199] Without limitation, the lipophilic groups in amphiphilic adhesives may include, but are not limited to, C. 1-8 Alkyl groups, and may further include, but are not limited to, C14 groups. 1-6 Alkyl groups, and further may include, but are not limited to, C14 groups. 1-4 Alkyl groups. Without limitation, the lipophilic groups in the amphiphilic adhesive may include, but are not limited to, one or more of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl.

[0200] In this application, unless otherwise specified, "alkyl" means a monovalent residue formed by the loss of a hydrogen atom from a saturated hydrocarbon containing a primary (normal) carbon atom, or a secondary carbon atom, or a tertiary carbon atom, or a quaternary carbon atom, or a combination thereof. Phrases containing this term, such as "C1-8 alkyl," refer to alkyl groups containing 1 to 8 carbon atoms, and each occurrence may independently be C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, or C8 alkyl. Suitable examples include, but are not limited to: methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -CH(CH3)2) )CH2CH3), 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl-2-butyl (-CH(CH3)CH(CH3)2), 3-methyl-1-butyl (-CH2C) H2CH(CH3)2), 2-methyl-1-butyl(-CH2CH(CH3)CH2CH3), 1-hexyl(-CH2CH2CH2CH2CH2CH3), 2-hexyl(-CH(CH3)CH2CH2CH2CH3), 3-hexyl(-CH(CH2CH3)(CH2CH2CH3)), 2-methyl-2-pentyl(-C(CH3)2CH2CH2CH3), 3-methyl-2-pentyl(-CH(CH3)CH(CH3)CH 2CH3), 4-methyl-2-pentyl (-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl (-C(CH3)(CH2CH3)2), 2-methyl-3-pentyl (-CH(CH2CH3)CH(CH3)2), 2,3-dimethyl-2-butyl (-C(CH3)2CH(CH3)2), 3,3-dimethyl-2-butyl (-CH(CH3)C(CH3)3), octyl (-(CH2)7CH3), 2-ethyl-hexyl, etc.

[0201] In some implementations, the amphiphilic adhesive satisfies one or more of the following characteristics:

[0202] The hydrophilic groups in amphiphilic adhesives include one or more of the following: chlorine atom, ether bond, carboxyl group, -C(=O)-O-, and amide group;

[0203] The lipophilic groups in amphiphilic adhesives include C 1-8 Alkyl groups, optionally including C 1-6 alkyl.

[0204] In some embodiments, the lipophilic groups in the amphiphilic adhesive include one or more of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl.

[0205] In some embodiments, the lipophilic groups in the amphiphilic adhesive include methyl groups.

[0206] By selecting amphiphilic binders with the aforementioned types of hydrophilic and lipophilic groups, it is beneficial to better control the contact angle value of the amphiphilic binder, to better promote the combined gain effect of hydrophilic and lipophilic groups, to better balance the van der Waals forces between hydrophilic groups and sulfides and the inhibitory effect of lipophilic groups on binder aggregation, and to promote more uniform dispersion of sulfide solid electrolyte and amphiphilic binder in the first electrolyte layer.

[0207] In some embodiments, the amphiphilic binder includes a carbon skeleton and side groups grafted onto the carbon skeleton, the side groups including hydrophilic and lipophilic groups.

[0208] In this application, the "carbon skeleton" in the amphiphilic binder can be a linear carbon chain, but is not limited to this.

[0209] By selecting an amphiphilic binder with the aforementioned structure, the synergistic effect between the carbon skeleton and the hydrophilic groups grafted onto the side groups is beneficial for better encapsulation of the sulfide solid electrolyte. The lipophilic groups grafted onto the side groups can inhibit the aggregation of the binder. This structural design is beneficial for promoting a more uniform dispersion of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer.

[0210] In some implementations, the amphiphilic adhesive includes amphiphilic rubber.

[0211] In this application, unless otherwise specified, "rubber" has the common meaning in the art, referring to a highly elastic polymer with reversible deformation capability. The glass transition temperature (Tg) of the "amphiphilic rubber" applicable to this application can be from -50°C to 30°C, which is beneficial for maintaining stable performance under battery operating and storage conditions.

[0212] In this application, "glass transition temperature (Tg)" has a well-known meaning in the art, corresponding to the temperature at which a polymer transitions from a glassy state to a rubbery state. It can be obtained by conventional methods in the art, such as testing, examples of which include dynamic mechanical analysis methods, further examples such as differential scanning calorimetry (DSC), but are not limited thereto.

[0213] In this application, unless otherwise specified, "amphiphilic rubber" refers to rubber that includes hydrophilic and lipophilic groups and has a certain contact angle value.

[0214] In some embodiments, the water contact angle of the amphiphilic rubber is any of the following values, or a range selected from any two of the following values, or greater than or equal to any of the following values ​​and less than 90°, or greater than any of the following values ​​and less than 90°: 20°, 22°, 24°, 25°, 26°, 28°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 86°, 87°, 88°, 89°, 90°, etc. The test temperature can be referred to the context definition, for example, 23±2℃. The contact angle value of the amphiphilic rubber can also be selected from any of the following ranges: 20°~90°, 30°~90°, 40°~90°, 45°~90°, 50°~90°, 60°~90°, 70°~90°, 80°~90°, 40°~85°, 20°~90° (including the left end but excluding 90°), 30°~90° (including the left end but excluding 90°), 40°~90° (including the left end but excluding 90°), 45°~90° (including the left end but excluding 90°), 50°~90° (including the left end but excluding 90°), 60°~90° (including the left end but excluding 90°), 70°~90° (including the left end but excluding 90°), etc. The test temperature can be referred to the context definition, for example, 23±2℃.

[0215] In this application, unless otherwise specified, the elastic deformation of amphiphilic rubber at 45°C is denoted as δ, and the elastic modulus of amphiphilic rubber at 30°C is denoted as E.

[0216] In some embodiments, the elastic deformation δ of the amphiphilic rubber at 45°C is ≥200%, and optionally, 450% ≤ δ ≤ 600%. Non-limitingly, δ may also be any of the following percentages or a range selected from any two of the following percentages: 200%, 250%, 300%, 350%, 400%, 450%, 500%, 550%, 600%, etc.

[0217] In some embodiments, the elastic modulus E of the amphiphilic rubber at 30°C is ≤100MPa; optionally, 50MPa ≤ E ≤ 85MPa. Non-limitingly, E may also be any of the following moduli or a range selected from any two of the following moduli: 50MPa, 60MPa, 65MPa, 70MPa, 75MPa, 80MPa, 85MPa, 90MPa, 95MPa, 100MPa, etc.

[0218] In some implementations, the amphiphilic rubber satisfies one or more of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in the context):

[0219] The elastic deformation of amphiphilic rubber at 45°C is denoted as δ, where δ ≥ 200%, and optionally, 450% ≤ δ ≤ 600%.

[0220] The elastic modulus of amphiphilic rubber at 30℃ is denoted as E, where E≤100MPa, and optionally, 50MPa≤E≤85MPa.

[0221] In some implementations, the amphiphilic rubber satisfies one or more of the following characteristics:

[0222] The elastic deformation of amphiphilic rubber at 45℃ satisfies 450% ≤ δ ≤ 600%;

[0223] The elastic modulus of amphiphilic rubber at 30℃ satisfies 50MPa≤E≤85MPa.

[0224] By introducing amphiphilic rubber with the aforementioned elastic deformation capacity and / or elastic modulus, the deformation capacity of the rubber can be used to further improve the contact between the amphiphilic binder and the sulfide solid electrolyte, thereby further improving the cycle performance of the solid-state battery.

[0225] On the other hand, improving the contact between the amphiphilic binder and the sulfide solid electrolyte is beneficial to further improving the discharge capacity of solid-state batteries.

[0226] Unless otherwise specified in this application, the elastic deformation and elastic modulus of amphiphilic rubber can be tested using conventional methods in the art, such as tensile testing. The elastic deformation and elastic modulus of amphiphilic rubber can be tested using the following method: the elastic modulus can be tested using a tensile testing machine according to the national standard GB / T 29895-2013. The tensile test involves applying a tensile force to the sample to cause deformation, measuring the stress-strain curve, and calculating the elastic modulus based on the slope of the linear strain region. An Instron 3365 tensile testing machine can be used.

[0227] In some embodiments, the amphiphilic rubber includes amphiphilic acrylate rubber.

[0228] In this application, unless otherwise specified, "amphiphilic acrylate rubber" refers to an acrylate rubber having any of the aforementioned suitable contact angle values, comprising repeating units with the structure -CH2-CH(-COOR)-, which can be formed by the polymerization of acrylate monomers CH2=CH(-COOR). In some embodiments, R is an alkyl group, and may further be C 1-8 Alkyl groups, which can further be C16-264 ... 1- 6-alkyl. Non-limiting, etc., the number of carbon atoms in R can be 1 to 8, and further can be 1, 2, 3, 4, 5, 6, 7, 8, or a range consisting of any two of the aforementioned values. In some embodiments, R is methyl.

[0229] In this application, "acrylate rubber" has the well-known meaning in the art, referring to a rubber polymerized from a main monomer, a vulcanizing point monomer, and a low-temperature oil-resistant monomer. The main monomer is generally an acrylate, but can further be an alkyl acrylate, and even further, C-acrylate. 1-8 Alkyl esters. Non-limiting examples of the main monomer include one or more of methyl acrylate, ethyl acrylate, etc. Non-limiting examples of low-temperature oil-resistant monomers include alkoxy ether acrylates, further such as methoxyethyl acrylate, etc., but not limited thereto. When synthesizing acrylate rubbers, a vulcanizing point monomer is often added to facilitate subsequent vulcanization processing. Based on the differences in reactive sites in the vulcanizing point monomer, acrylate rubbers can be classified into types such as chlorinated, epoxy, double-bond, and carboxyl types.

[0230] In some embodiments, the ester type in the amphiphilic acrylate rubber may include, but is not limited to, -COOR (the definition of -COOR can be found above) depending on the difference in the side groups in the main monomer. In some embodiments, the amphiphilic acrylate rubber includes amphiphilic alkyl acrylate rubber, and further, the amphiphilic acrylate rubber includes amphiphilic C-acrylate rubber. 1-8 Alkyl ester rubbers.

[0231] In some embodiments, based on the differences in the reactive sites of the vulcanization point monomers, amphiphilic acrylate rubbers may include one or more of the following: chlorinated acrylate rubber, active chlorinated acrylate rubber, epoxy acrylate rubber, carboxyl acrylate rubber, double bond acrylate rubber, double crosslinked acrylate rubber, and ethylene methyl acrylate rubber.

[0232] In this application, unless otherwise specified, chlorinated acrylate rubber and reactive chlorinated acrylate rubber have the meanings known in the art, both containing chlorine atoms. Relatively speaking, the chlorine atoms in reactive chlorinated acrylate rubber are more reactive than those in chlorinated acrylate rubber. Examples of vulcanizing point monomers used in chlorinated acrylate rubber include 2-chloroethyl vinyl ether (CEVE). Examples of vulcanizing point monomers used in reactive chlorinated acrylate rubber include vinyl chloroacetate (VCA). Examples of epoxy-type vulcanizing point monomers include glycidyl methacrylate (GMA) and allyl glycidyl ether (AGE). Examples of double-bond-type vulcanizing point monomers include ethylene-2-norbornene (5-ethylidene-2-norbornene, ENB). Examples of carboxylic acid-type vulcanizing point monomers include maleic acid monoester and imidazolic acid monoester. Double-crosslinked acrylate rubber refers to a monomer with two reactive sites at its vulcanization point. For example, it can be a chlorine / carboxyl combination type including chlorine atoms and carboxyl groups, or an epoxy / carboxyl combination type including epoxy groups and carboxyl groups.

[0233] By introducing the aforementioned amphiphilic acrylate rubber, it is beneficial to better control the contact angle value of the amphiphilic binder, to better promote the combined gain effect of hydrophilic and lipophilic groups, to better balance the van der Waals forces between hydrophilic groups and sulfides and the inhibitory effect of lipophilic groups on binder aggregation, and to promote more uniform dispersion of sulfide solid electrolyte and amphiphilic binder in the first electrolyte layer.

[0234] In some embodiments, the first electrolyte layer satisfies one or more of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in the context):

[0235] The amphiphilic binder has a weight percentage of 0.5 wt% to 15 wt% in the first electrolyte layer, optionally 1 wt% to 15 wt%, and further optionally 2 wt% to 15 wt%.

[0236] The amphiphilic adhesive accounts for more than or equal to 10% by weight in the first adhesive, and can be selected from 10% to 100%, and more preferably from 30% to 100%.

[0237] The amphiphilic adhesive includes an amphiphilic rubber, wherein the weight percentage of the amphiphilic rubber in the first electrolyte layer is 0.5 wt% to 15 wt%, optionally 1 wt% to 15 wt%;

[0238] Amphiphilic adhesives include amphiphilic rubber, wherein the weight percentage of amphiphilic rubber in the first adhesive is greater than or equal to 10%, and can be selected as 30% to 100%;

[0239] The first adhesive also includes one or more of the following adhesives: nitrile rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, natural rubber, polyvinylidene fluoride, etherified cellulose, polymethyl methacrylate, polyethylene oxide, and methyl vinyl silicone rubber;

[0240] The thickness of the first electrolyte layer is 10 μm to 70 μm, optionally 20 μm to 50 μm, and further optionally 20 μm to 50 μm.

[0241] In some embodiments, the first electrolyte layer satisfies one or more of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in the context):

[0242] In the first electrolyte layer, the weight ratio of the amphiphilic binder to the sulfide solid electrolyte is (2-20):100, and can be (2-18):100.

[0243] In the first electrolyte layer, the amphiphilic binder includes amphiphilic rubber, and the weight ratio of the amphiphilic rubber to the sulfide solid electrolyte is (2-20):100, optionally (2-18):100.

[0244] Non-limitingly, the weight percentage of the amphiphilic binder in the first electrolyte layer can be 0.5 wt% to 15 wt%, optionally 1 wt% to 15 wt%, further optionally 2 wt% to 15 wt%, and can also be any of the following percentages or a range selected from any two of the following percentages: 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, etc.

[0245] Non-limitingly, the amphiphilic adhesive may constitute 10% or more by weight in the first adhesive, preferably 10% to 100%, further preferably 30% to 100%, or any of the following percentages or a range consisting of any two of the following percentages: 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 70%, 80%, 90%, 100%, etc.

[0246] Non-limitingly, the weight percentage of the amphiphilic rubber in the first electrolyte layer can be 0.5 wt% to 15 wt%, optionally 1 wt% to 15 wt%, or any of the following percentages or a range selected from any two of the following percentages: 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, etc.

[0247] Non-limitingly, the amphiphilic rubber may constitute 10% or more by weight in the first adhesive, preferably 10% to 100%, further preferably 30% to 100%, or any of the following percentages or a range consisting of any two of the following percentages: 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 70%, 80%, 90%, 100%, etc.

[0248] Without limitation, the first adhesive includes an amphiphilic adhesive and may also include one or more of the following adhesives: nitrile rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, natural rubber, polyvinylidene fluoride, etherified cellulose, polymethyl methacrylate, polyethylene oxide, and methyl vinyl silicone rubber.

[0249] Non-limitingly, the thickness of the first electrolyte layer can be 10 μm to 70 μm, optionally 20 μm to 50 μm, further optionally 20 μm to 50 μm, and can also be any of the following thicknesses or a range selected from any two of the following thicknesses: 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc.

[0250] Non-limitingly, in the first electrolyte layer, the weight ratio of the amphiphilic binder to the sulfide solid electrolyte can be denoted as N1:100, where N1 can be a value selected from 2 to 20, or a value selected from the range of 2 to 18, or a range selected from any of the following values ​​or any two of the following values: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, etc. In some embodiments, the weight ratio of the amphiphilic binder to the sulfide solid electrolyte can be (2 to 20):100, or optionally (2 to 18):100.

[0251] Non-limitingly, in the first electrolyte layer, the weight ratio of the amphiphilic rubber to the sulfide solid electrolyte can be denoted as N2:100, where N2 can be a value selected from 2 to 20, a value selected from the range of 2 to 18, or a value selected from any of the following values ​​or a range consisting of any two of the following values: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, etc. In some embodiments, the weight ratio of the amphiphilic rubber to the sulfide solid electrolyte can be (2-20):100, or optionally (2-18):100.

[0252] The content of the amphiphilic binder in the first electrolyte layer can be adjusted by adjusting one or more of the following parameters: the weight percentage of the amphiphilic binder in the first electrolyte layer, the weight ratio of the amphiphilic binder in the first binder, the weight percentage of the amphiphilic rubber in the first electrolyte layer, the weight ratio of the amphiphilic rubber in the first binder, the weight ratio of the amphiphilic binder to the sulfide solid electrolyte, and the weight ratio of the amphiphilic rubber to the sulfide solid electrolyte.

[0253] By controlling one or more of the following parameters within the aforementioned ranges: the weight percentage of the amphiphilic binder in the first electrolyte layer, the weight proportion of the amphiphilic binder in the first binder, and the weight ratio of the amphiphilic binder to the sulfide solid electrolyte, it is beneficial to better achieve one or more advantages such as improving the component dispersion uniformity of the first electrolyte layer, optimizing the electrical contact network, improving interfacial adhesion strength and interfacial stability, and reducing interfacial impedance. This is beneficial to better improve the cycle performance of solid-state batteries. Simultaneously, solid-state batteries also exhibit good ion transport performance, thus achieving good battery kinetics. Similarly, by controlling one or more of the following parameters within the aforementioned ranges: the weight proportion of the amphiphilic rubber in the first binder, the weight percentage of the amphiphilic rubber in the first electrolyte layer, and the weight ratio of the amphiphilic rubber to the sulfide solid electrolyte, it is beneficial to better improve the electrical contact network in the first electrolyte layer, thereby further improving the cycle performance of solid-state batteries.

[0254] By controlling the thickness of the first electrolyte layer within the aforementioned range, it is possible to promote the better performance of the amphiphilic binder while also taking into account the ion transport performance between the first and second electrode layers, thus better controlling the influence of the binder in the first electrolyte layer on the overall resistivity of the solid electrolyte layer.

[0255] In some embodiments, in solid-state batteries or electrolyte electrodes, including but not limited to in solid electrolyte layers, including but not limited to in first electrolyte layers, the sulfide solid electrolyte may include at least one of binary sulfide solid systems and ternary sulfide solid systems. Non-limitingly, the binary sulfide solid system may include one or more of Li₂S-P₂S₅, Li₂S-SiS₂, Li₂S-GeS₂, and Li₂S-B₂S₃. Non-limitingly, the ternary sulfide solid system may include one or more of the following: silver sulfide-germanium sulfide electrolyte, Li2S-MeS2-P2S5 ternary sulfide electrolyte, lithium germanium phosphorus sulfide electrolyte, Li2S-P2S5-MS ternary sulfide electrolyte, Li2S-P2S5-MCl ternary sulfide electrolyte, and thio-LISICON type sulfide electrolyte; wherein, Me may include one or more elements selected from silicon (Si), germanium (Ge), tin (Sn), and aluminum (Al), and may further be selected from one or more elements selected from Si, Ge, Sn, and Al; M may include one or more elements selected from Ge, Al, Sn, lead (Pb), antimony (Sb), Si, and arsenic (As), and may further be selected from one or more elements selected from Ge, Al, Sn, Pb, Sb, Si, and As.

[0256] In some embodiments, the sulfide solid electrolyte includes one or more of the following: LGPS type sulfide electrolyte, silver-germanium sulfide type sulfide electrolyte, lithium sulfide-phosphorus pentasulfide complex sulfide electrolyte, and thio-LISICON sulfide electrolyte.

[0257] Unless otherwise specified, the sulfide electrolytes of the sulfide type have a sulfide-germanium type crystal phase structure. Without limitation, the sulfide electrolyte may include electrolytes with the chemical formula Li 6±s P 1-j A j S 5±s-t B t X 1±s The electrolyte is a sulfide electrolyte, wherein 0 ≤ j < 1, 0 ≤ t < 1, 0 ≤ s < 1, A can be selected from, but is not limited to, one or more elements selected from Ge, Si, Sn, and Sb, B can be one or more elements selected from O, Se, and Te, and X can be selected from one or more elements selected from Cl, Br, I, and F. In some embodiments, X is a halogen, and further, X can be selected from one or more elements selected from Cl, Br, I, and F.

[0258] In some embodiments, the sulfide solid electrolyte in the first electrolyte layer includes Li6PS5X, where X is a halogen, and further, X may be selected from one or more elements selected from Cl, Br and I.

[0259] Unless otherwise specified, the sulfide electrolyte of the LGPS type has a LGPS-type crystal phase structure. Without limitation, the sulfide electrolyte of the LGPS type may include a sulfide electrolyte having the chemical formula Li 10±δ5 Ge 1-g G g P 2-q Q q S 12-w W w where 0 ≤ δ5 < 1, 0 ≤ g ≤ 1, 0 ≤ q ≤ 2, 0 ≤ w < 1, G is selected from one or both of the elements Si and Sn, Q is Sb, and W is selected from one or more of the elements O, Se, Te, Cl, Br, I, and F.

[0260] Without limitation, the sulfide electrolyte of the lithium sulfide-phosphorus pentasulfide complex type may include a sulfide electrolyte having the chemical formula (100 - u - v)Li2S·uP2S5·vM m N n where 0 < u < 100, 0 ≤ v < 100, 0 ≤ u + v < 100, 0 ≤ m < 4, 0 ≤ n < 6, M may be selected from one or more of the elements Li, B, Ge, Si, Sn, and Sb, and N may be selected from one or more of the elements S, Se, Te, O, Cl, Br, I, and F.

[0261] In some embodiments, the sulfide solid electrolyte includes Li 6-x PS 5-x Cl 1+x where 0 ≤ x ≤ 0.9. Non-limiting examples of x are 0, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and may also be selected from within the range formed by any two of the foregoing values, and may also be greater than 0 and less than or equal to any one of the foregoing non-zero values.

[0262] When selecting the sulfide solid electrolyte of the foregoing type, the foregoing improvement effects can be achieved.

[0263] By doping the sulfide solid electrolyte with chlorine (Cl) element, the (Cl) element can replace a part of the sulfur (S) element, which is beneficial to further reducing the hydrogen sulfide gas release amount of the sulfide solid electrolyte in an aqueous environment.

[0264] In some embodiments, the solid electrolyte layer further includes a second electrolyte layer, and the second electrolyte layer is located between the second electrode layer and the first electrolyte layer;

[0265] where the second electrolyte layer includes a solid electrolyte (which may be denoted as the second solid electrolyte), and may also optionally include a binder (which may be denoted as the second binder).

[0266] In the present application, the binder located in the first electrolyte layer may be denoted as "the first binder", the binder located in the second electrolyte layer may be denoted as "the second binder", the solid electrolyte located in the first electrolyte layer may be denoted as "the first solid electrolyte", the solid electrolyte located in the second electrolyte layer may be denoted as "the second solid electrolyte", and the binder located in the negative electrode layer may be denoted as "the negative electrode binder".

[0267] In the present application, in "the first binder", "the second binder", "the first solid electrolyte", "the second solid electrolyte", etc., the terms "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first" and "second" only serve the purpose of non-exhaustive enumerative description and should be understood not to constitute a closed limitation on quantity.

[0268] In some embodiments, the second electrolyte layer includes or does not include an amphiphilic binder.

[0269] In some embodiments, the second electrolyte layer includes a binder. In some of these embodiments, the second electrolyte layer includes an amphiphilic binder.

[0270] In the present application, the weight percentage of the amphiphilic binder in the second electrolyte layer is denoted as f12, and the weight percentage of the amphiphilic binder in the first electrolyte layer is denoted as f11.

[0271] In some embodiments, the second electrolyte layer satisfies one or more of the following characteristics (any numerical parameter in the following characteristics may also be selected from any suitable value or range in the context):

[0272] 0 ≤ f12 < f11;

[0273] The weight percentage f12 of the amphiphilic binder in the second electrolyte layer is 0 wt% to 5 wt%.

[0274] In some embodiments, f12 < f11. At this time, the weight percentage of the amphiphilic binder in the second electrolyte layer is lower than the weight percentage of the amphiphilic binder in the first electrolyte layer.

[0275] In some embodiments, 0 ≤ f12 < f11, optionally, 0 < f12 < f11.

[0276] In some embodiments, the weight percentage (f12) of the amphiphilic binder in the second electrolyte layer can be 0 wt% to 5 wt%, optionally 0 wt% to 3 wt%, or can be any of the following percentages or a range selected from any two of the following percentages: 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, etc.

[0277] In some embodiments, a solid-state battery is provided, comprising a first electrode layer, a solid electrolyte layer, and a second electrode layer stacked sequentially; wherein the solid electrolyte layer includes a first electrolyte layer and a second electrolyte layer, and the first electrolyte layer is located between the second electrolyte layer and the first electrode layer;

[0278] The first electrolyte layer includes a sulfide solid electrolyte and a first binder. The first binder includes an amphiphilic binder, which includes hydrophilic groups and lipophilic groups.

[0279] In some embodiments, a solid-state battery is provided, comprising a first electrode layer, a solid electrolyte layer, and a second electrode layer stacked sequentially; wherein the solid electrolyte layer includes a first electrolyte layer and a second electrolyte layer, and the first electrolyte layer is located between the second electrolyte layer and the first electrode layer;

[0280] The first electrolyte layer includes a first solid electrolyte and a first binder. The first solid electrolyte includes a sulfide solid electrolyte, and the first binder includes an amphiphilic binder, which includes hydrophilic groups and lipophilic groups.

[0281] In some implementations, solid-state batteries satisfy one or more of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in the context):

[0282] The total thickness of the solid electrolyte layer is greater than 15 μm, and can be selected from 30 μm to 110 μm, and further selected from 40 μm to 90 μm;

[0283] The thickness of the second electrolyte layer is greater than or equal to 10 μm, optionally greater than or equal to 20 μm, further optionally 20 μm to 45 μm, and even more preferably 30 μm to 40 μm;

[0284] The thickness of the second electrolyte layer is greater than the thickness of the first electrolyte layer;

[0285] The binder content in the second electrolyte layer is lower than that in the first electrolyte layer, by weight percentage;

[0286] The second binder has a weight percentage of 0 wt% to 5 wt% in the second electrolyte layer;

[0287] The solid electrolyte in the second electrolyte layer accounts for 95 wt% to 100 wt% of the total weight of the second electrolyte layer.

[0288] Non-limitingly, the total thickness of the solid electrolyte layer can be greater than 15 μm, and can be selected from 30 μm to 110 μm, further selected from 40 μm to 90 μm, and can also be any of the following thicknesses or a range selected from any two of the following thicknesses: 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, etc.

[0289] Non-limitingly, the thickness of the second electrolyte layer may be greater than or equal to 10 μm, optionally greater than or equal to 20 μm, further optionally 20 μm to 45 μm, even further optionally 30 μm to 40 μm, and may also be any of the following thicknesses or a range selected from any two of the following thicknesses: 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, etc.

[0290] By controlling the thickness of the solid electrolyte layer and / or the second electrolyte layer as described above, it is beneficial to reduce the risk of short circuits and improve the reliability of solid-state batteries.

[0291] In some embodiments, the thickness of the second electrolyte layer is greater than the thickness of the first electrolyte layer.

[0292] By controlling the thickness of the second electrolyte layer to be greater than that of the first electrolyte layer, the solid electrolyte layer can simultaneously improve the adhesion strength between the first electrolyte layer and the first electrode layer and fully utilize the fast ion transport properties of the second electrolyte layer.

[0293] By incorporating a solid electrolyte layer that simultaneously includes a first electrolyte layer and a second electrolyte layer, the first electrolyte layer improves the cycle performance of the solid-state battery while simultaneously reducing its thickness within a given total thickness. This allows for better control over the influence of the binder in the first electrolyte layer on the overall resistivity of the solid electrolyte layer. Furthermore, by controlling the second electrolyte layer to have a lower binder content and / or a higher solid electrolyte content, the solid electrolyte layer can simultaneously improve the adhesion strength between the first electrolyte layer and the first electrode layer while fully utilizing the fast ion transport capabilities of the second electrolyte layer.

[0294] In some embodiments, the binder content in the second electrolyte layer is lower than the binder content in the first electrolyte layer by weight percentage; that is, the content of the second binder in the second electrolyte layer is lower than the content of the first binder in the first electrolyte layer.

[0295] By controlling the binder content in the second electrolyte layer to be lower than that in the first electrolyte layer, the second electrolyte layer can provide higher ionic conductivity, allowing the solid electrolyte layer to both improve the adhesion strength between the first electrolyte layer and the first electrode layer and fully utilize the fast ion transport properties of the second electrolyte layer.

[0296] Non-limitingly, the weight percentage of the second binder in the second electrolyte layer can be 0 wt% to 5 wt%, or it can be any of the following percentages or a range selected from any two of the following percentages: 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, etc.

[0297] Non-limitingly, in the second electrolyte layer, the weight percentage of the solid electrolyte in the second electrolyte layer can be 95wt% to 100wt%, or it can be any of the following percentages or a range selected from any two of the following percentages: 95wt%, 95.5wt%, 96wt%, 96.5wt%, 97wt%, 97.5wt%, 98wt%, 98.5wt%, 99wt%, 99.5wt%, 100wt%, etc.

[0298] In some embodiments, the second electrolyte layer does not include an amphiphilic binder.

[0299] In some implementations, the second electrolyte layer does not include an adhesive.

[0300] In some embodiments, the second electrolyte layer is composed of a solid electrolyte.

[0301] In some embodiments, the second electrolyte layer consists of a solid electrolyte and a binder (denoted as the second binder).

[0302] In some implementations, the first electrode layer is a negative electrode layer and the second electrode layer is a positive electrode layer.

[0303] By placing the first electrolyte layer on one side of the negative electrode layer, it is beneficial to improve the adhesion between the negative electrode layer and the solid electrolyte layer, reduce the interfacial impedance between the negative electrode layer and the solid electrolyte layer, and thus improve the cycle performance of the solid-state battery.

[0304] In some embodiments, the negative electrode layer includes a negative electrode current collector and a negative electrode active material layer located on at least one side of the negative electrode current collector, and a first electrolyte layer located on the side of the negative electrode active material layer away from the negative electrode current collector. Further, the first electrolyte layer is located on the surface of the negative electrode active material layer on the side away from the negative electrode current collector.

[0305] In some embodiments, a solid-state battery is provided, comprising a negative electrode layer, a solid electrolyte layer, and a positive electrode layer stacked sequentially; wherein the solid electrolyte layer includes a first electrolyte layer and a second electrolyte layer, the first electrolyte layer being located between the second electrolyte layer and the negative electrode layer.

[0306] In some embodiments, the first electrolyte layer comprises a sulfide solid electrolyte and a first binder, the first binder comprising an amphiphilic binder, further comprising hydrophilic groups and lipophilic groups.

[0307] In some embodiments, the first electrolyte layer includes a first solid electrolyte and a first binder, the first solid electrolyte including a sulfide solid electrolyte, and the first binder including an amphiphilic binder, further comprising hydrophilic groups and lipophilic groups.

[0308] In some embodiments, the negative electrode active material layer includes a binder (denoted as negative electrode binder).

[0309] It is understood that the negative electrode layer includes at least a negative electrode active material layer, which comprises a negative electrode active material. In some embodiments, the negative electrode active material layer comprises a silicon-based material.

[0310] In some embodiments, the negative electrode active material layer satisfies one or more of the following characteristics:

[0311] The negative electrode active material layer includes a negative electrode binder;

[0312] The negative electrode active material layer includes a negative electrode active material, which includes silicon-based materials. Without limitation, the silicon-based material may include, but is not limited to, one or more of elemental silicon, silicon-carbon composite materials, and silicon oxides.

[0313] In some embodiments, the first electrolyte layer and the negative electrode active material layer are in contact.

[0314] In some implementations, the solid-state battery is an all-solid-state battery.

[0315] In this application, unless otherwise specified, "all-solid-state battery" refers to a solid-state battery in which all electrolytes are solid electrolytes. In this case, the positive electrode layer, negative electrode layer and electrolyte part are all made of solid materials, and no liquid electrolyte is provided in the battery, so it can be called "all-solid-state battery".

[0316] A solid-state battery includes at least one solid-state battery cell. A solid-state battery may include one or more solid-state battery cells.

[0317] In this application, unless otherwise specified, "solid-state battery cell" refers to a basic unit capable of converting chemical energy into electrical energy, and all its components are solid-state. In some embodiments, a solid-state battery cell may be an all-solid-state battery cell.

[0318] In this application, unless otherwise specified, "all-solid-state battery cell" refers to a solid-state battery cell in which all electrolytes are solid electrolytes. In this case, the positive electrode layer, negative electrode layer and electrolyte part are all made of solid materials, and no liquid electrolyte is provided in the battery cell, so it can be called "all-solid-state battery cell".

[0319] Non-limitingly, a solid-state battery cell (which can be an all-solid-state battery cell) may include a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, with the solid electrolyte layer located between the positive and negative electrode layers. During battery charging and discharging, active ions shuttle between the positive and negative electrode layers, inserting and extracting. The solid electrolyte layer serves to conduct ions between the positive and negative electrode layers and also isolates them, thus preventing short circuits between the positive and negative electrodes.

[0320] In some embodiments, the solid-state battery cell 5 includes a solid-state cell 52.

[0321] In some implementations, the solid-state cell is an all-solid-state cell.

[0322] In some embodiments, the solid-state cell 52 (which may be an all-solid-state cell) includes a first electrode layer 10, a solid electrolyte layer 300, and a second electrode layer 20 stacked sequentially, one example of which is shown in FIG. 6. In some embodiments, the solid electrolyte layer 300 includes a first electrolyte layer 310 located on the side close to the first electrode layer 10, one example of which is shown in FIG. 7.

[0323] In some embodiments, the solid-state cell 52 (which may be an all-solid-state cell) includes a first electrode layer 10, a first electrolyte layer 310, and a second electrode layer 2, which are stacked sequentially.

[0324] In some embodiments, the solid-state cell 52 (which may be an all-solid-state cell) includes a first electrode layer 10, a first electrolyte layer 310, a second electrolyte layer 320 and a second electrode layer 20 stacked sequentially, one example of which can be found in FIG8.

[0325] In some embodiments, the solid-state cell 52 (which may be an all-solid-state cell) includes a negative electrode layer 100, a solid electrolyte layer 300 and a positive electrode layer 200 stacked sequentially, one example of which can be found in FIG9.

[0326] In some embodiments, the solid-state cell 52 (which may be an all-solid-state cell) includes a negative electrode layer 100, a first electrolyte layer 310, a second electrolyte layer 320 and a positive electrode layer 200 stacked sequentially, one example of which can be found in FIG10.

[0327] In some embodiments, the solid-state battery may include an outer packaging. This outer packaging can be used to encapsulate the aforementioned solid-state battery cell.

[0328] In some embodiments, the outer packaging of a solid-state battery can be a rigid shell, such as a hard plastic shell, an aluminum shell, or a steel shell. The outer packaging of a solid-state battery can also be a soft pack, such as a pouch-type soft pack. The material of the soft pack can be plastic; further, non-limiting examples of plastics may include one or more of polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0329] This application does not impose any particular limitation on the shape of the solid-state battery cell; it can be cylindrical, square, or any other arbitrary shape. For example, Figure 11 shows a square solid-state battery cell 5 as an example.

[0330] In some embodiments, referring to FIG12, the outer packaging may include a housing 51 and a cover plate 53. The housing 51 may include a base plate and side plates connected to the base plate, the base plate and side plates forming a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the cover plate 53 can be placed over the opening to close the receiving cavity. A solid-state battery cell 52 is encapsulated within the receiving cavity. The number of solid-state battery cells 52 contained in the solid-state battery cell 5 may be one or more, which can be selected by those skilled in the art according to actual needs.

[0331] Solid-state batteries can be battery device 4 or battery pack 1.

[0332] The battery device includes at least one solid-state battery cell. The number of solid-state battery cells in the battery device can be one or more, and those skilled in the art can select an appropriate number according to the application and capacity of the battery device.

[0333] Figure 13 shows a battery device 4 as an example. Referring to Figure 13, in the battery device 4, multiple solid-state battery cells 5 can be arranged sequentially along the length of the battery device 4. Of course, they can also be arranged in any other arbitrary manner. Furthermore, the multiple solid-state battery cells 5 can be fixed in place by fasteners.

[0334] Optionally, the battery device 4 may also include a housing with a receiving space in which a plurality of solid-state battery cells 5 are housed.

[0335] In some embodiments, the battery devices described above can also be assembled into a battery pack, and the number of battery devices contained in the battery pack can be one or more. Those skilled in the art can select an appropriate number according to the application and capacity of the battery pack.

[0336] Figures 14 and 15 show a battery pack 1 as an example. Referring to Figures 14 and 15, the battery pack 1 may include a battery box and a plurality of battery devices 4 disposed within the battery box. The battery box includes an upper box 2 and a lower box 3, the upper box 2 covering the lower box 3 to form a closed space for accommodating the battery devices 4. The plurality of battery devices 4 may be arranged in any manner within the battery box.

[0337] The following are some additional descriptions of the solid electrolyte layer.

[0338] The formation of the solid electrolyte layer can be found in the fourth aspect of this application, but is not limited thereto.

[0339] The solid electrolyte layer acts as a conductor of ions between the positive and negative electrode layers, and can also isolate the positive and negative electrode layers to prevent short circuits between them.

[0340] It is understood that the solid electrolyte layer includes solid electrolytes. The types of solid electrolytes in the solid electrolyte layer can be found in the context of this application.

[0341] The types of solid electrolytes present in different film layers of a solid-state battery can be the same or different. For example, the types of solid electrolytes in the positive electrode layer and the solid electrolyte layer can be the same or different.

[0342] In some embodiments of this application, the solid electrolyte layer includes at least a first electrolyte layer. The definition of the first electrolyte layer can be found in the first aspect of this application. In some embodiments, the solid electrolyte layer may also optionally include a second electrolyte layer. The types of solid electrolytes in the first electrolyte layer and the second electrolyte layer may be the same or different.

[0343] In some embodiments of this application, the first electrolyte layer includes a sulfide-based solid electrolyte. The first electrolyte layer may also include solid electrolytes known in the art and suitable for solid-state batteries. In the first electrolyte layer, these solid electrolytes may be used alone or in combination of two or more. In some embodiments, the first electrolyte layer may also include one or more of the following materials: halide-based solid electrolytes, oxide-based solid electrolytes, polymer-based solid electrolytes, etc.

[0344] In this application, "sulfide solid electrolyte" and "sulfide solid electrolyte" have the same meaning and can be used interchangeably. A sulfide solid electrolyte can be a sulfide or any suitable modified form of a sulfide. Sulfide solid electrolytes can be modified using conventional methods in the art or methods suitable for the solid-state batteries of this application to obtain new sulfide solid electrolytes.

[0345] As a non-limiting example, in the second electrolyte layer, the solid electrolyte includes one or more of sulfide solid electrolytes, halide solid electrolytes, oxide solid electrolytes, and polymer solid electrolytes. In some non-limiting examples, the solid electrolyte in the second electrolyte layer may include, but is not limited to, one or more of oxide solid electrolytes, sulfide solid electrolytes, and halide solid electrolytes.

[0346] Non-limiting examples of oxide solid electrolytes may include LISICON-type oxide electrolytes (such as γ-Li3PO4, etc.) and NASICON-type oxide electrolytes (such as Li...). 1+x Al x Ge 2-x (PO4)3,Li 1+x Al x Ti 2-x (PO4)3, etc., 0≤x≤1), Garnet type (such as Li7La3Zr2O) 12 (etc.), perovskite-type oxide electrolytes (such as Li, etc.) 3x La 2 / 3-x One or more of TiO3, etc. (0≤x≤0.5), etc.

[0347] Non-limiting examples of sulfide solid electrolytes may include Li 10 GeP2S 12 Li₂S-P₂S₅, Argyrodite type (such as Li₆PS₅Cl, Li 5.5 PS 5.5 Cl 1.5 One or more of the following: etc.

[0348] Non-limiting examples of halide solid electrolytes may include one or more of Li3InCl6, Li3YCl6, Li3ScCl6, Li3ErCl6, Li2ZrCl6, etc.

[0349] The following are some other descriptions of the negative electrode layer.

[0350] In some implementations, the negative electrode layer may be provided by an electrolyte negative electrode sheet as described in the context of this application.

[0351] In other embodiments, the negative electrode layer may be formed based on a solid electrolyte membrane or provided by a pre-fabricated negative electrode sheet, which may be a negative electrode sheet that is available in the art for use in solid-state batteries.

[0352] The negative electrode sheet can be prepared by dry or wet methods. For example, it can be formed into a film by dry pressing. Alternatively, it can be formed into a film by wet coating.

[0353] In this application, unless otherwise specified, the negative electrode layer includes at least a negative electrode active material layer.

[0354] Unless otherwise stated in this application, the negative electrode sheet includes at least a negative electrode active material layer.

[0355] Unless otherwise stated in this application, the negative electrode active material layer includes at least negative electrode active particles.

[0356] Without limitation, the negative electrode active material layer may include a solid electrolyte. The solid electrolyte in the negative electrode active material layer may be referred to as "negative electrode electrolyte particles".

[0357] In this application, unless otherwise specified, "negative electrode electrolyte particles" refers to a solid electrolyte that can be used in the negative electrode layer. Negative electrode electrolyte particles can enhance the ion conductivity of the negative electrode layer, reduce interfacial impedance, and promote the charge transfer efficiency and full release of the capacity of the negative electrode active material with the external environment. The type of negative electrode electrolyte particles can be the same as or different from those in the solid electrolyte layer.

[0358] In this application, unless otherwise stated, "negative electrode active particles" refers to particles containing negative electrode active substances that have the ability to reversibly insert and extract active ions.

[0359] Without limitation, the weight percentage of negative electrode active particles or negative electrode active materials in the negative electrode active material layer can be ≥80wt%, and more preferably ≥90wt%.

[0360] Non-limiting, the weight percentage of the negative electrode electrolyte particles in the negative electrode active material layer can be 0 to 30 wt%, preferably 0.1 wt% to 30 wt%, and further preferably 5 wt% to 20 wt%.

[0361] In some embodiments, the negative electrode active particles or negative electrode active material are lithium indium alloys (InLi alloys).

[0362] In some implementations, the negative electrode layer or negative electrode sheet is an InLi alloy electrode sheet.

[0363] In some embodiments, the negative electrode active material may also be a negative electrode active material known in the art for use in solid-state batteries. As a non-limiting example, the negative electrode active material may include one or more of the following materials: elemental silicon, elemental tin, silicon-carbon composites, silicon suboxide, graphite, and metallic lithium. However, this application is not limited to these materials or substances, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0364] In some embodiments, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector, the negative electrode active material layer comprising a negative electrode active substance. As a non-limiting example, the negative electrode current collector has two surfaces opposite to each other in its own thickness direction, and the negative electrode active material layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector. In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. In the negative electrode current collector, the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. In the negative electrode current collector, the composite current collector may be formed by forming a metal material on the polymer material base layer. Non-limiting examples of the metal material in the negative electrode current collector may include one or more of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. In the negative electrode current collector, non-limiting examples of the polymeric material substrate may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.

[0365] In some embodiments, the negative electrode active material layer optionally includes a conductive agent (which may be referred to as a negative electrode conductive agent). Non-limitingly, the negative electrode conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. Non-limitingly, the weight percentage of the negative electrode conductive agent in the negative electrode active material layer may be 0–15 wt%, more preferably 0–10 wt%, and even more preferably 0–5 wt%.

[0366] In some embodiments, the negative electrode active material layer optionally includes a binder (denoted as negative electrode binder). As a non-limiting example, the negative electrode binder may include one or more of polyvinylidene fluoride (PVDF), styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS). Non-limitingly, the weight percentage of the negative electrode binder in the negative electrode active material layer may be 0–10 wt%, more preferably 0–5 wt%, even more preferably 1 wt%–5 wt%, and even more preferably 1 wt%–3 wt%.

[0367] In some embodiments, the negative electrode active material layer may optionally include other additives, such as thickeners (e.g., sodium carboxymethyl cellulose (CMC-Na)). The weight percentage of the other additives in the negative electrode active material layer may be 0–15 wt%, more preferably 0–10 wt%, even more preferably 0–5 wt%, even more preferably 0–3 wt%, and even more preferably 0–2 wt%.

[0368] In some embodiments, the negative electrode sheet can be prepared by dispersing the components used to prepare the negative electrode sheet, such as negative electrode active particles, negative electrode conductive agent, negative electrode binder, and any other components, in a solvent (non-limiting examples of solvents include p-xylene, N-methyl-2-pyrrolidone (NMP), etc.), to form a negative electrode slurry. Further, the negative electrode slurry is coated onto at least one surface of the negative electrode current collector, and after drying, cold pressing, and other processes, the negative electrode sheet is obtained. Cold pressing can be performed using a cold rolling mill. The surface of the negative electrode current collector coated with the negative electrode slurry can be a single surface of the negative electrode current collector or both surfaces of the negative electrode current collector. The solid content of the negative electrode slurry can be 30wt% to 70wt%, optionally 40wt% to 60wt%. The viscosity of the negative electrode slurry at room temperature can be adjusted to 2000 mPa·s to 10000 mPa·s, optionally 3000 mPa·s to 10000 mPa·s. When coating the negative electrode slurry, the coating density per unit area (after deducting solvent) on a dry weight basis, based on the amount coated on one side of the negative electrode current collector, can be 1.3 mg / cm³. 2 ~22mg / cm 2 However, this is not the only possibility. The compaction density of the negative electrode sheet can be 1.0 g / cm³. 3 ~2.0g / cm 3 1.0g / cm³ is an optional value. 3 ~1.8g / cm 3 .

[0369] The following is a description of the positive electrode layer.

[0370] The positive electrode layer can be formed based on a solid electrolyte membrane or provided by a pre-fabricated positive electrode sheet, which can be a positive electrode sheet that is available in the art for use in solid-state batteries.

[0371] Positive electrode sheets can be prepared using dry or wet methods. For example, they can be dry-pressed into films. Alternatively, they can be wet-coated and dried to form films.

[0372] In some embodiments, the positive electrode layer includes a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector.

[0373] Unless otherwise stated, the positive electrode layer in this application includes at least a positive electrode active material layer.

[0374] Unless otherwise stated in this application, the positive electrode sheet includes at least a positive active material layer.

[0375] In this application, unless otherwise specified, the positive electrode active material layer includes at least positive electrode active particles, and usually also includes positive electrode electrolyte particles.

[0376] In this application, unless otherwise specified, "positive electrode active particles" refers to particles containing positive electrode active substances that have the ability to reversibly extract and insert active ions.

[0377] In this application, unless otherwise specified, "positive electrode electrolyte particles" refers to solid electrolytes that can be used in the positive electrode layer. Positive electrode electrolyte particles can enhance the ion conductivity of the positive electrode layer, reduce interfacial impedance, and promote the charge transfer efficiency and full release of the capacity of the positive electrode active material with the external environment.

[0378] In some embodiments, the positive electrode active material may be a known positive electrode active material for batteries. As a non-limiting example, the positive electrode active material may include one or more of the following materials: lithium-containing phosphates with an olivine structure, lithium transition metal oxides, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium transition metal oxides include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and their modified compounds. Non-limiting examples of lithium-containing phosphates with an olivine structure include, but are not limited to, one or more of lithium iron phosphate, lithium iron phosphate and carbon composites, lithium manganese phosphate, lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium manganese iron phosphate and carbon composites. Non-limiting examples of lithium cobalt oxides may include LiCoO2; non-limiting examples of lithium nickel oxides may include LiNiO2; non-limiting examples of lithium manganese oxides may include LiMnO2, LiMn2O4, etc.; non-limiting examples of lithium nickel cobalt manganese oxides may include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 Examples of lithium nickel cobalt aluminum oxides include LiNi, etc. 0.80 Co 0.15 Al 0.05 O2. Examples of lithium iron phosphate include LiFePO4 (also known as LFP). Examples of lithium manganese phosphate include LiMnPO4.

[0379] Understandably, lithium (Li) is intercalated and deintercalated during the charging and discharging process of a battery, resulting in different Li content in the positive electrode layer or positive electrode sheet when the battery is discharged to different states. In the exemplary description of the positive electrode active material in this application, unless otherwise specified, the Li content can be the initial state of the material or a non-initial state after charge-discharge cycles. When the positive electrode active material is applied to the positive electrode in a battery system, the Li content in the positive electrode active material at the positive electrode will usually change after charge-discharge cycles. The Li content can be measured in atomic molar content, but is not limited to this. Regarding "Li content is the initial state of the material," the initial state of the material refers to the state before it is made into the positive electrode active material layer. It is understood that new materials or substances obtained by appropriate modification based on the listed positive electrode active materials are also within the scope of positive electrode active materials. The aforementioned appropriate modification refers to an acceptable modification method for the positive electrode active material, and non-limiting examples include coating modification.

[0380] In the exemplary description of the positive electrode active material in this application, the oxygen (O) content is only a theoretical value. Lattice oxygen release will cause changes in the atomic molar content of oxygen, and the actual O content will fluctuate. The O content can be measured using atomic molar content, but is not limited to this.

[0381] Non-limiting, the weight percentage of positive electrode active particles or positive electrode active materials in the positive electrode active material layer can be ≥70wt%, further ≥80wt%, even further ≥90wt%, and can also be 70wt% to 99wt%, optionally 80wt% to 95wt%.

[0382] Non-limiting, the weight percentage of positive electrode electrolyte particles in the positive electrode active material layer can be 0.1 wt% to 30 wt%, and optionally 5 wt% to 20 wt%.

[0383] In some embodiments, the positive electrode active material layer includes positive electrode electrolyte particles. Non-limitingly, the weight percentage of the positive electrode electrolyte particles in the positive electrode active material layer can be from 0.1 wt% to 30 wt%, optionally from 5 wt% to 20 wt%.

[0384] In some embodiments, the positive electrode active material layer includes positive electrode active particles and positive electrode electrolyte particles.

[0385] In some embodiments, the positive electrode active material layer includes a conductive agent (which may be referred to as a positive electrode conductive agent). As a non-limiting example, the positive electrode conductive agent may be a carbon conductive agent. Non-limitingly, the carbon conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In some embodiments, the positive electrode conductive agent may include, but is not limited to, one or more of SP, KS-6, acetylene black, branched Ketjen black ECP, SFG-6, vapor-grown carbon fibers (VGCF), carbon nanotubes (CNTs), and graphene. Non-limitingly, the weight percentage of the positive electrode conductive agent in the positive electrode active material layer may be 0–10 wt%, more further 0–8 wt%, even further 0–5 wt%, and even further 0.1 wt%–3 wt%. When the positive electrode material is prepared into a positive electrode active material layer using a dry method, the positive electrode conductive agent can be incorporated into the positive electrode material, which can improve the conductivity of the positive electrode active material layer.

[0386] In some embodiments, the positive electrode active material layer optionally includes a binder (which may be referred to as a positive electrode binder). As a non-limiting example, the positive electrode binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), a terpolymer of PVDF-tetrafluoroethylene-propylene, a terpolymer of PVDF-hexafluoropropylene-tetrafluoroethylene, a tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resins. The aforementioned non-limiting examples of positive electrode binders are all organic binders and belong to organic components. Typically, the weight percentage of the positive electrode binder in the positive electrode active material layer can be 0–10 wt%, more commonly 0–8 wt%, even more commonly 0.1 wt%–5 wt%, and even more commonly 1 wt%–5 wt%. When the positive electrode material is formulated into a positive electrode slurry using a wet process and then the positive electrode active material layer is prepared, the positive electrode binder can be placed in the positive electrode slurry, which can assist in film formation and also promote the formation of a good electrical contact network between the active particles in the positive electrode active material layer.

[0387] Non-limiting, the positive electrode active material layer may include positive electrode active particles, positive electrode electrolyte particles, positive electrode conductive agent, and positive electrode binder. The types and contents of each component can be found in the context of this application.

[0388] As a non-limiting example, the positive current collector has two surfaces that are opposite to each other in its own thickness direction, and the positive active material layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0389] In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. In the positive electrode current collector, the composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. In the positive electrode current collector, the composite current collector may be obtained by forming a metal material on the polymer material substrate. Non-limiting examples of the metal material in the positive electrode current collector may include at least one of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. Non-limiting examples of the polymer material substrate in the positive electrode current collector may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0390] In some embodiments, the positive electrode sheet can be prepared by: dry mixing the components used to prepare the positive electrode sheet, such as positive electrode active particles, positive electrode electrolyte particles, positive electrode conductive agent, positive electrode binder, and any other components; then heating and pressurizing the mixed material to knead it into a clump; hot rolling pressing to form a self-supporting positive electrode sheet; and hot rolling bonding the self-supporting positive electrode sheet with a positive electrode current collector, wherein the self-supporting positive electrode sheet can be bonded to at least one side (single or double sides) of the positive electrode current collector to obtain the positive electrode sheet. Non-limitingly, a dual planetary mixer can be used for dry mixing. Non-limitingly, a kneading and pressing process can be performed using a Banbury mixer. Non-limitingly, the temperature for hot rolling pressing can be 75°C to 85°C, and further, such as 78°C, 80°C, 82°C, etc. The method of assembling solid-state batteries using positive electrode sheets is suitable for industrial mass production.

[0391] In some embodiments, the positive electrode sheet can be prepared by dispersing the components used to prepare the positive electrode sheet, such as positive electrode active particles, positive electrode electrolyte particles, positive electrode conductive agent, positive electrode binder, and any other components, in an organic solvent to form a positive electrode slurry. Further, the positive electrode slurry is coated onto at least one surface of the positive electrode current collector, and after drying, cold pressing, and other processes, the positive electrode sheet is obtained. Cold pressing can be performed using a cold rolling mill. Non-limitingly, the organic solvent in the positive electrode slurry can include one or more of p-xylene, trimethylbenzene, butyl butyrate, heptane, etc., and more specifically, p-xylene. The surface of the positive electrode current collector coated with the positive electrode slurry can be a single surface of the positive electrode current collector or both surfaces of the positive electrode current collector. The solid content of the positive electrode slurry can be 40 wt% to 80 wt%. The viscosity of the positive electrode slurry at room temperature can be adjusted to 5000 mPa·s to 25000 mPa·s. When coating the positive electrode slurry, the coating density per unit area, measured by dry weight (excluding solvent), can be 15 mg / cm³, based on the amount coated on one side of the positive electrode current collector. 2 ~35mg / cm2 However, this is not the only possibility. The compaction density of the positive electrode sheet can be 2.0 g / cm³. 3 ~3.6g / cm 3 2.3g / cm³ is an option. 3 ~3.5g / cm 3 .

[0392] In a second aspect of this application, a solid electrolyte membrane is provided, which includes a first electrolyte layer as defined in the first aspect of this application.

[0393] The solid electrolyte membrane includes a first electrolyte layer as defined in the first aspect of this application. The first electrolyte layer includes a sulfide solid electrolyte and an amphiphilic binder. By introducing an amphiphilic binder having both hydrophilic and lipophilic groups into the first electrolyte layer, the van der Waals forces between the hydrophilic groups and the sulfide can strengthen the bond between the binder and the sulfide solid electrolyte. The presence of the lipophilic groups helps to inhibit the aggregation of the binder, promotes the uniform dispersion of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer, and promotes the transport of active ions in the solid electrolyte layer, thereby improving the cycle performance of the solid-state battery including the solid electrolyte membrane.

[0394] On the other hand, the improved dispersion uniformity of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer is beneficial to improving the contact network between the sulfide solid electrolytes, increasing the adhesion, improving the stability and mechanical strength of the first electrolyte layer and the solid electrolyte membrane, promoting the transport of active ions, and thus improving the cycle performance and discharge capacity of the solid battery including the solid electrolyte membrane.

[0395] On the other hand, the improved dispersion uniformity of the sulfide solid electrolyte and the amphiphilic binder in the first electrolyte layer is beneficial to improving the adhesion strength of the first electrolyte layer on the first electrode layer, which is beneficial to reducing the interfacial stability and interfacial impedance between the solid electrolyte membrane and the adjacent electrode layer, thereby improving the cycle stability and discharge capacity of the solid battery including the solid electrolyte membrane.

[0396] Furthermore, the first electrolyte layer can be formed by coating and drying a slurry comprising a sulfide solid electrolyte, a binder, and an organic solvent. When a low-polarity or non-polar solvent is selected as the organic solvent, the high reactivity of the sulfide solid electrolyte can easily lead to insufficient uniform dispersion of the sulfide solid electrolyte in the slurry. By introducing an amphiphilic binder with both hydrophilic and lipophilic groups into the first electrolyte layer, the good compatibility of the lipophilic groups with the solvent and the van der Waals forces between the hydrophilic groups and the sulfide can improve the uniformity of dispersion of the sulfide solid electrolyte in the slurry, thereby improving the uniformity of dispersion of the sulfide solid electrolyte in the first electrolyte layer. This further improves the cycle performance of the solid-state battery including the solid electrolyte membrane, and further improves the film strength and adhesion strength of the first electrolyte layer on the film substrate, significantly reducing the risk of film detachment.

[0397] In some embodiments, a solid electrolyte membrane is provided, comprising a sulfide solid electrolyte and an amphiphilic binder, wherein the amphiphilic binder comprises hydrophilic and lipophilic groups. The definition of "amphiphilic binder" can also be found in the relevant description within the context of this application.

[0398] In some embodiments, a solid electrolyte membrane is provided, comprising a sulfide solid electrolyte and a first binder, the first binder comprising an amphiphilic binder comprising hydrophilic and lipophilic groups.

[0399] In some embodiments, a solid electrolyte membrane is provided, comprising a first solid electrolyte and a first binder, wherein the first solid electrolyte comprises a sulfide solid electrolyte, and the first binder comprises an amphiphilic binder, further comprising hydrophilic groups and lipophilic groups.

[0400] In a third aspect of this application, an electrolyte electrode is provided, comprising an electrode body and a first electrolyte layer, the first electrolyte layer being located on at least one side of the electrode body. The definition of the first electrolyte layer can be found in the first aspect of this application.

[0401] In some implementations, the first electrolytic layer is as defined in the first aspect of this application.

[0402] In some embodiments, an electrolyte electrode 93 is provided, which includes an electrode body 901 and a first electrolyte layer 310 located on at least one side of the electrode body, one example of which can be seen in FIG1.

[0403] The electrolyte electrode includes an electrode body and a first electrolyte layer located on at least one side of the electrode body. As mentioned above, by utilizing the amphiphilic properties of the amphiphilic binder in the first electrolyte layer, the sulfide solid electrolyte and the amphiphilic binder can be uniformly dispersed in the first electrolyte layer, thereby improving the cycle performance of the solid-state battery including the electrolyte electrode.

[0404] On the other hand, the introduction of amphiphilic binders facilitates the contact network between sulfide solid electrolytes, thereby improving the cycle performance and discharge capacity of solid-state batteries including the electrolyte electrode.

[0405] On the other hand, the introduction of amphiphilic binders can improve the adhesion strength of the first electrolyte layer on the electrode body, reduce the interfacial stability and interfacial impedance between the solid electrolyte membrane and the electrode body, and thus improve the cycle stability and discharge capacity of the solid-state battery including the electrolyte electrode.

[0406] The first electrolyte layer in the electrolyte electrode can also be formed by coating and drying a slurry comprising a sulfide solid electrolyte, a binder, and an organic solvent. As mentioned earlier, by utilizing the amphiphilic properties of the amphiphilic binder in the first electrolyte layer, the dispersion uniformity of the sulfide solid electrolyte in the slurry can be improved, thereby improving the dispersion uniformity of the sulfide solid electrolyte in the first electrolyte layer, and further improving the cycle performance of the solid-state battery including the electrolyte electrode.

[0407] The electrode body 901 includes at least an electrode active material layer 920.

[0408] In some embodiments, the electrode body 901 includes a current collector 910 and an electrode active material layer 920 located on at least one side of the current collector. In some embodiments, in the electrolyte electrode 93, the electrode active material layer 920 is located between the current collector 910 and the first electrolyte layer 310.

[0409] In some embodiments, the electrolyte electrode 93 includes a current collector 910 and an electrode active material layer 920 and a first electrolyte layer 310 sequentially disposed on at least one side of the current collector 910, one example of which can be seen in FIG2.

[0410] In some embodiments, an electrolyte electrode is provided. In some embodiments, the electrode body includes a current collector and an electrode active material layer located on at least one side of the current collector, and a solid electrolyte membrane is located on the side of the electrode active material layer away from the current collector. In this case, the electrode active material layer is located between the current collector and the solid electrolyte membrane.

[0411] In some embodiments, the solid electrolyte membrane is located on the surface of the electrode active material layer away from the current collector.

[0412] In some embodiments, the electrolyte electrode sheet is an electrolyte negative electrode sheet, and the electrode body is a negative electrode body. Accordingly, the current collector is a negative electrode current collector, and the electrode active material layer is a negative electrode active material layer.

[0413] In some embodiments, an electrolyte negative electrode 13 is provided, which includes a negative electrode body 101 and a first electrolyte layer 310 located on at least one side of the negative electrode body 101. The definition of the first electrolyte layer can be found in the first aspect of this application. An example of the electrolyte negative electrode 13 can be found in FIG3.

[0414] In some embodiments, an electrolyte negative electrode sheet is provided, comprising a negative electrode body and a solid electrolyte membrane located on at least one side of the negative electrode body; the solid electrolyte membrane includes a first electrolyte layer. Further, the first electrolyte layer is located on the side of the solid electrolyte membrane closer to the negative electrode body.

[0415] In some embodiments, the negative electrode body 101 includes a negative electrode current collector 110 and a negative electrode active material layer 120 located on at least one side of the negative electrode current collector 110. Further, in the electrolyte negative electrode sheet 13, a first electrolyte layer 310 is located on the side of the negative electrode active material layer 120 away from the negative electrode current collector 110. Further, the first electrolyte layer 310 is located on the surface of the negative electrode active material layer 120 on the side away from the negative electrode current collector 110.

[0416] In some embodiments, an electrolyte negative electrode 13 is provided, which includes a negative electrode layer 100 and a first electrolyte layer 310 located on at least one side of the negative electrode layer 100, one example of which can be seen in FIG4.

[0417] In some embodiments, the negative electrode layer 100 includes a negative electrode current collector 110 and a negative electrode active material layer 120 located on at least one side of the negative electrode current collector 110. Further, the negative electrode active material layer 120 is located between the negative electrode current collector 110 and the first electrolyte layer 310.

[0418] The electrolyte electrode can be selected as the electrolyte negative electrode. In this case, the first electrolyte layer can be placed on the side of the negative electrode layer in the solid-state battery. This is beneficial to improve the adhesion between the negative electrode layer and the solid electrolyte layer, reduce the interfacial impedance between the negative electrode layer and the solid electrolyte layer, and thus improve the cycle performance of the solid-state battery.

[0419] The negative electrode layer 100 includes at least a negative electrode active material layer 120.

[0420] In some embodiments, the electrolyte negative electrode sheet 13 includes a negative electrode current collector 110 and a negative electrode active material layer 120 and a first electrolyte layer 310 sequentially disposed on at least one side of the negative electrode current collector 110, one example of which can be seen in FIG5.

[0421] In some embodiments, the negative electrode active material layer satisfies one or more of the following characteristics:

[0422] The negative electrode active material layer includes a negative electrode binder;

[0423] The negative electrode active material layer includes a negative electrode active material, which includes silicon-based materials.

[0424] In some embodiments, the negative electrode active material layer includes a negative electrode binder. The type of negative electrode binder and its content in the negative electrode active material layer (e.g., content by weight percentage) can be found in the relevant description in the context of this application, for example, in the first aspect of this application.

[0425] In some embodiments where the negative electrode active material layer includes a negative electrode binder, the amphiphilic binder in the first electrolyte layer helps to improve the connection between the first electrolyte layer and the negative electrode active material layer, thereby increasing the adhesion strength between the first electrolyte layer and the negative electrode layer.

[0426] In some embodiments, the negative electrode active material layer includes a negative electrode active substance, which includes a silicon-based material. The types of silicon-based materials can be found in the relevant description within the context of this application, for example, in the first aspect of this application.

[0427] In some embodiments where the negative electrode active material layer includes silicon-based materials, the introduction of an amphiphilic binder in the first electrolyte layer is also beneficial to improving the interfacial contact stability between the first electrolyte layer and the negative electrode layer when the silicon-based material undergoes volume expansion or contraction, which is conducive to achieving better cycle performance.

[0428] The preparation methods of electrolyte electrodes and electrolyte negative electrodes can be found in the context of this application, for example, in the fourth aspect of this application.

[0429] In some embodiments of the fourth aspect of this application, a method for preparing a solid-state battery is provided, comprising the following steps:

[0430] S100: Prepare an electrolyte electrode sheet; wherein the electrolyte electrode sheet includes a first electrode layer and a first electrolyte layer located on at least one side of the first electrode layer; the first electrolyte layer includes a sulfide solid electrolyte and an amphiphilic binder;

[0431] S200: A second electrode layer is formed on the side of the first electrolyte layer away from the first electrode layer.

[0432] The definition of amphiphilic adhesives can be found in the first aspect of this application.

[0433] In some embodiments, the amphiphilic adhesive includes both hydrophilic and lipophilic groups.

[0434] In some embodiments, the contact angle value of the amphiphilic adhesive can be found in the first aspect of this application.

[0435] The solid-state battery prepared includes the advantages described in the first aspect of this application, which will not be repeated here.

[0436] In some embodiments, the first electrolyte layer is formed on at least one side of the first electrode layer by coating and drying an electrolyte slurry;

[0437] The electrolyte slurry includes solid electrolytes, amphiphilic binders, and organic solvents; the solid electrolytes include sulfide solid electrolytes.

[0438] In some embodiments, the electrolyte electrode can be prepared by a method including the following steps:

[0439] An electrolyte slurry is coated onto at least one side surface of a first electrode sheet and dried to prepare an electrolyte electrode sheet; wherein the first electrode sheet forms a first electrode layer and the dried electrolyte slurry forms a first electrolyte layer.

[0440] When the first electrolyte layer is formed by wet process using electrolyte slurry, an amphiphilic binder with both hydrophilic and lipophilic groups can be introduced into the first electrolyte layer. The good compatibility of the lipophilic groups with the solvent and the van der Waals forces between the hydrophilic groups and the sulfide can improve the dispersion uniformity of the sulfide solid electrolyte in the slurry, thereby improving the dispersion uniformity of the sulfide solid electrolyte in the first electrolyte layer, and further improving the cycle performance of the solid battery.

[0441] In some embodiments, the electrolyte electrode is an electrolyte negative electrode, and the solid-state battery preparation method includes the following steps:

[0442] S100: An electrolyte slurry is coated onto at least one side surface of a negative electrode sheet and dried to prepare an electrolyte negative electrode sheet; wherein, the negative electrode sheet forms a negative electrode layer, and the dried electrolyte slurry forms a first electrolyte layer;

[0443] S210: A second electrolyte layer and a positive electrode layer are formed sequentially on the side of the first electrolyte layer away from the negative electrode layer.

[0444] For the preparation method of the negative electrode sheet, please refer to the context of this application.

[0445] In some embodiments, the dielectric constant ε of the organic solvent in the electrolyte slurry satisfies: ε≤6.5.

[0446] In this application, unless otherwise specified, the dielectric constant of organic solvents can be tested using the frequency method, which determines the dielectric constant based on the polarization phenomenon of solvent molecules under an alternating electric field. The testing instrument includes a frequency-adjustable AC power supply and a capacitance meter. The test can be performed as follows: the organic solvent to be tested is injected into the capacitance meter until it is fully filled; the frequency f of the AC power supply is set and connected to the capacitance meter; the capacitance value C at different frequencies is measured and recorded; the dielectric constant ε is calculated according to the following formula. Where K is the electrostatic constant, K = 9.0 × 10⁻⁶ 9 N·m 2 / C 2 C is the capacitance; d is the distance between the two plates; S is the area of ​​the two plates facing each other; the capacitance C can be calculated using the following formula: Where ω is the angular velocity, Z” is the imaginary part of the complex impedance (or the capacitive reactance); ω=2πf.

[0447] In some embodiments, the organic solvent in the electrolyte slurry includes organic solvent A, wherein the dielectric constant ε of organic solvent A is ≤ 6.5. Optionally, organic solvent A includes one or more of a low-polarity solvent and a non-polar solvent.

[0448] In some embodiments, the organic solvent in the electrolyte slurry includes one or more organic solvents with a dielectric constant less than or equal to 6.5.

[0449] In some embodiments, the organic solvent in the electrolyte slurry includes one or more of a low-polarity solvent and a non-polar solvent; non-limitingly, the dielectric constant ε1 of the low-polarity solvent satisfies: 2.6 < ε1 ≤ 6.5; and the dielectric constant ε2 of the non-polar solvent satisfies: ε2 ≤ 2.6.

[0450] In some embodiments, the organic solvent in the electrolyte slurry includes substituted benzene, wherein the phenyl group in the substituted benzene is replaced by one or more substituents selected from the substituent group G, which includes methyl, chlorine, and methoxy groups.

[0451] In some embodiments, the organic solvent in the electrolyte slurry may include, but is not limited to, one or more of xylene, butyl butyrate, octyl butyrate, trimethylbenzene, chlorobenzene, dimethyl carbonate, ethyl acetate, n-hexane, anisole, dibromomethane, triethyl phosphate, isopropyl ether, and benzyl acetate. Butyrate may include one or more of n-butyl butyrate, isobutyl isobutyrate, etc. Further, the organic solvent in the electrolyte slurry may include one or more of p-xylene, pseudotrimethylbenzene, butyl butyrate (examples of butyl butyrate include one or more of n-butyl butyrate, isobutyl isobutyrate, etc.), and octyl butyrate.

[0452] In some embodiments, the organic solvent in the electrolyte slurry is 30 wt% to 90 wt%, optionally 40 wt% to 70 wt%, or any of the following percentages or a range selected from any two of the following percentages: 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, etc.

[0453] In some embodiments, the organic solvent with a dielectric constant less than or equal to 6.5 is present in the electrolyte slurry at a weight percentage of 30 wt% to 90 wt%, optionally 40 wt% to 70 wt%, or any of the following percentages or a range selected from any two of the following percentages: 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, etc.

[0454] In some embodiments, the amphiphilic binder has a weight percentage of 0.5wt% to 6wt% in the electrolyte slurry, and can be selected as 1wt% to 6wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 6wt%, etc.

[0455] In some embodiments, the organic solvent in the electrolyte slurry satisfies one or more of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in the context):

[0456] Organic solvents include one or more of low-polarity solvents and non-polar solvents; wherein, the dielectric constant ε1 of the low-polarity solvent satisfies: 2.6 < ε1 ≤ 6.5; and the dielectric constant ε2 of the non-polar solvent satisfies: ε2 ≤ 2.6.

[0457] Organic solvents include substituted benzenes, wherein the phenyl group in the substituted benzene is replaced by one or more substituents selected from the substituent group G, which includes: methyl, chlorine, and methoxy groups;

[0458] The organic solvent with a dielectric constant less than or equal to 6.5 has a weight percentage of 50 wt% to 100 wt% in the organic solvent, and can be optionally 70 wt% to 100 wt%.

[0459] The organic solvents include one or more of xylene, butyl butyrate, octyl butyrate, thallium, chlorobenzene, dimethyl carbonate, ethyl acetate, n-hexane, anisole, dibromomethane, triethyl phosphate, isopropyl ether, and benzyl acetate; optionally, the organic solvents include one or more of p-xylene, pseudotrimethylbenzene, butyl butyrate (examples of butyl butyrate include one or more of n-butyl butyrate, isobutyl isobutyrate, etc.), and octyl butyrate;

[0460] The organic solvent accounts for 30 wt% to 90 wt% of the electrolyte slurry; optionally, the organic solvent accounts for 40 wt% to 70 wt% of the electrolyte slurry.

[0461] The amphiphilic binder has a weight percentage of 0.5 wt% to 6 wt% in the electrolyte slurry, and can be selected as 1 wt% to 6 wt%.

[0462] For electrolyte slurry systems containing the aforementioned organic solvents, selecting low-polarity or non-polar solvents can reduce side reactions with the highly reactive sulfide solid electrolyte. Furthermore, by introducing an amphiphilic binder with both hydrophilic and lipophilic groups into the first electrolyte layer, the good compatibility of the lipophilic groups with the aforementioned organic solvents and the van der Waals forces between the hydrophilic groups and the sulfides can improve the dispersion uniformity of the sulfide solid electrolyte in the electrolyte slurry system, thereby improving the dispersion uniformity of the sulfide solid electrolyte in the first electrolyte layer, and further improving the cycle performance of the solid-state battery.

[0463] In some embodiments, the electrolyte electrode is the electrolyte electrode described in the third aspect of this application, and the first electrode layer includes a corresponding electrode body.

[0464] In some embodiments, the solid-state battery prepared is the solid-state battery described in the first aspect of this application.

[0465] In a fifth aspect of this application, an electrical device is provided, comprising at least one of the solid-state battery described in the first aspect of this application, the solid electrolyte membrane described in the second aspect of this application, the electrolyte electrode described in the third aspect of this application, and a solid-state battery prepared by the method for preparing a solid-state battery described in the fourth aspect of this application.

[0466] In some of these embodiments, the power supply device includes a solid-state battery according to any of the embodiments provided in this application.

[0467] In a non-limiting sense, solid-state batteries can be used as a power source for electrical devices or as an energy storage unit for electrical devices. Electrical devices can include, but are not limited to, mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, etc. Mobile devices can be, for example, mobile phones, laptops, etc.; electric vehicles can be, for example, pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, electric motorcycles, power tools, etc., but are not limited to these. This electrical device can also be applied to military equipment, aerospace, and other fields, and can also be applied to energy storage power systems such as hydroelectric, thermal, wind, and solar power plants.

[0468] As an electrical device, solid-state batteries can be selected based on its usage requirements.

[0469] Figure 16 shows an example of an electrical device 6. This electrical device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. To meet the high power and high energy density requirements of this electrical device for solid-state batteries, a battery pack or battery device can be used.

[0470] Another example device could be a mobile phone, tablet, or laptop. These devices typically require a thin and light design and can use solid-state batteries as their power source.

[0471] The following describes some embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where the technology or conditions are not specified in the embodiments, they are performed according to the description above, or according to the technology or conditions described in the literature in this field, or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially, or can be synthesized from commercially available products using conventional methods.

[0472] It should be noted that the following embodiments and examples use all-solid-state batteries as non-limiting examples of solid-state batteries.

[0473] In the following examples, unless otherwise specified, the amphiphilic rubbers used all satisfy the following conditions: elastic deformation (δ) at 45°C is in the range of 200% ≤ δ ≤ 600%, and elastic modulus (E) at 30°C is in the range of 50 MPa ≤ E ≤ 100 MPa. Specifically, the amphiphilic rubber used in Example 1 satisfies the following conditions: elastic deformation (δ) at 45°C is in the range of 450% ≤ δ ≤ 600%, and elastic modulus (E) at 30°C is in the range of 50 MPa ≤ E ≤ 85 MPa.

[0474] The testing methods for elastic deformation and elastic modulus are as follows: According to the national standard GB / T 29895-2013, the elastic modulus is tested using a tensile testing machine (Instron 3365 tensile testing machine). The tensile test involves applying a tensile force to the material to cause deformation and measuring the stress-strain curve. At a test temperature of 30℃, the elastic modulus is calculated based on the slope of the linear region, using the portion where strain is linear. The elastic deformation of the amphiphilic rubber at 45℃ is obtained at a test temperature of 45℃.

[0475] In the following examples, the contact angle values ​​of the amphiphilic adhesives, using amphiphilic rubber as an example, were obtained by testing as follows: at a test temperature of 23°C, the amphiphilic adhesive was dissolved in an organic solvent (such as xylene) to prepare an adhesive solution, which was then coated on a flat plate (such as Al foil) and dried to form a film; water droplets were dropped onto the surface of the film material, and the side view of the droplets was captured under an optical microscope. The shape of the droplets was analyzed using geometric principles, and the obtained contact angle values ​​were recorded.

[0476] In the following examples, regarding the dielectric constant of the organic solvents in the electrolyte slurry, p-xylene and pseudotrimethylbenzene are used as examples. The dielectric constant of p-xylene is approximately 2.25, and the dielectric constant of pseudotrimethylbenzene is approximately 2.3.

[0477] The dielectric constant of organic solvents was determined using the frequency method: the organic solvent to be tested was injected into the capacitance meter until it was full; the frequency f of the AC power supply was set, and the power supply was connected to the capacitance meter; the capacitance value C at different frequencies was measured and recorded; according to the following formula... The dielectric constant ε of the organic solvent was calculated; the meaning of each symbol can be found in the previous text.

[0478] In the following embodiments and comparative examples, unless otherwise stated, the steps involving sulfide-based electrolyte materials are performed in an argon atmosphere.

[0479] The amphiphilic rubbers used in the following examples are all commercially available.

[0480] I. Preparation of Electrolyte Slurry and Solid Electrolyte Membrane

[0481] (I) Preparation of solid electrolyte membranes

[0482] Example M1. Preparation of solid electrolyte membrane

[0483] Aluminum (Al) foil with a thickness of 12 μm was cleaned with ethanol or benzene-based solvents, dried and flattened at 60℃~70℃, and then used for later use. In this example, anhydrous ethanol was used for cleaning.

[0484] The sulfide solid electrolyte Li6PS5Cl, the binder ethylene methyl acrylate rubber (ethylene methyl acrylate rubber 3430), and the solvent p-xylene were mixed at a mass ratio of 0.45:0.05:0.5 to obtain an electrolyte slurry. The solid content was 50 wt%.

[0485] Taking the total mass of the sulfide solid electrolyte slurry as 100%, 45% by mass of sulfide solid electrolyte, 5% by mass of ethylene methyl acrylate rubber, and 50% by mass of p-xylene were mixed and dispersed in a defoamer for 15 minutes to form an electrolyte slurry. The electrolyte slurry was transferred into a glove box and coated onto a cleaned 12 μm thick Al foil using a coater to a thickness of 30 μm. The coating was then dried at 110°C (600 minutes in this example) to obtain a solid electrolyte film formed on the Al foil. The total thickness after drying was approximately 35 μm.

[0486] It should be noted that, on a dry weight basis, the mass ratio of sulfide solid electrolyte to ethylene methyl acrylate rubber is 45%:5%. When mixing, first use a portion of the solvent p-xylene to dissolve the ethylene methyl acrylate rubber to prepare a rubber solution, and then mix the sulfide solid electrolyte, the rubber solution, and the remaining measured amount of solvent.

[0487] In this example, the contact angle of the ethylene methyl acrylate rubber is 85°, which is an amphiphilic rubber, and it includes the hydrophilic group -C(=O)O- and the lipophilic group methyl.

[0488] Example M2. A solid electrolyte membrane was prepared using a method essentially the same as that in Example M1, except that the mass ratio of the sulfide solid electrolyte Li6PS5Cl, the binder ethylene methyl acrylate rubber, and the solvent was changed to 0.34:0.06:0.6 when preparing the electrolyte slurry, and the solid content was 40wt%. The remaining operating steps were the same as in Example M1.

[0489] Example M3. A solid electrolyte membrane was prepared using a method essentially the same as that in Example 1, except that the mass ratio of the sulfide solid electrolyte Li6PS5Cl, the binder ethylene methyl acrylate rubber, and the solvent was changed to 0.395:0.055:0.55 when preparing the electrolyte slurry, and the solid content was 45wt%. The remaining operation steps were the same as in Example M1.

[0490] Example M4. A solid electrolyte membrane was prepared using a method essentially the same as that in Example 1, except that the mass ratio of the sulfide solid electrolyte Li6PS5Cl, the binder ethylene methyl acrylate rubber, and the solvent was changed to 0.505:0.045:0.45 when preparing the electrolyte slurry, and the solid content was 55wt%. The remaining operating steps were the same as in Example M1.

[0491] Example M5. A solid electrolyte membrane was prepared using a method essentially the same as that used in Example M2, except that the mass ratio of the sulfide solid electrolyte Li6PS5Cl, the binder ethylene methyl acrylate rubber, and the solvent was changed to 0.39:0.01:0.6 when preparing the electrolyte slurry, and the solid content was 40wt%. The remaining operating steps were the same as in Example M1.

[0492] Example M6. A solid electrolyte membrane was prepared using a method essentially the same as that used in Example M2, except that the mass ratio of the sulfide solid electrolyte Li6PS5Cl, the binder ethylene methyl acrylate rubber, and the solvent was changed to 0.095:0.005:0.9 when preparing the electrolyte slurry, and the solid content was 10wt%. The remaining operating steps were the same as in Example M1.

[0493] Example M7. A solid electrolyte membrane was prepared using a method essentially the same as that used in Example M1, except that the type of binder, ethylene methyl acrylate, was changed to chlorinated acrylate rubber (chlorinated acrylate rubber ACM-2012); the remaining operating steps were the same as in Example M1.

[0494] In this example, the contact angle of the chlorinated acrylate rubber is 43°, which is an amphiphilic rubber.

[0495] Example M8. A solid electrolyte membrane was prepared using a method essentially the same as that used in Example M1, except that the type of binder, ethylene methyl acrylate, was changed to epoxy acrylate rubber (epoxy acrylate rubber 4053EP); the remaining operating steps were the same as in Example M1.

[0496] In this example, the contact angle of the epoxy acrylate rubber is 62°, which is an amphiphilic rubber.

[0497] Example M9. A solid electrolyte membrane was prepared using a method essentially the same as that used in Example M1, except that the type of binder, ethylene methyl acrylate, was changed to a double-bond type acrylate rubber (3-methyl-2-butenyl ester type); the remaining operating steps were the same as in Example M1.

[0498] In this example, the contact angle of the double-bond acrylate rubber is 88°, which is an amphiphilic rubber.

[0499] Example M10. A solid electrolyte membrane was prepared using a method essentially the same as that in Example M1, except that the mass ratio of the sulfide solid electrolyte Li6PS5Cl, the binder ethylene methyl acrylate rubber (same as in Example M1), the binder nitrile rubber (NBR1704), and the solvent was changed to 0.45:0.025:0.025:0.5 when preparing the electrolyte slurry. The remaining operating steps were the same as in Example M1.

[0500] In this example, the adhesive is a combination of ethylene methyl acrylate rubber and nitrile rubber. The contact angle of the nitrile rubber NBR1704 is 150°.

[0501] Example M11. A solid electrolyte membrane was prepared using a method essentially the same as that in Example M10, except that the mass ratio of the sulfide solid electrolyte Li6PS5Cl, the binder ethylene methyl acrylate rubber (same as in Example M10), the binder nitrile rubber (same as in Example M10), and the solvent was changed to 0.45:0.015:0.035:0.5, and the solid content was 50wt%. The remaining operating steps were the same as in Example M10.

[0502] Example M12. A solid electrolyte membrane was prepared using a method essentially the same as that in Example M10, except that the mass ratio of the sulfide solid electrolyte Li6PS5Cl, the binder ethylene methyl acrylate rubber (same as in Example M10), the binder nitrile rubber (same as in Example M10), and the solvent was changed to 0.4:0.01:0.09:0.5, and the solid content was 50wt%. The remaining operating steps were the same as in Example M10.

[0503] Example M13. A solid electrolyte membrane was prepared using essentially the same method as in Example M1, except that the solvent p-xylene was changed to pseudotrimethylbenzene. The remaining steps were the same as in Example M1.

[0504] Comparative Example M1. A solid electrolyte membrane was prepared using a method essentially the same as that in Example 1, except that the type of binder, ethylene methyl acrylate, was changed to nitrile rubber (NBR1704); the remaining operating steps were the same as in Example M1.

[0505] In this example, the contact angle of nitrile rubber is 150°, which does not qualify it as an amphiphilic adhesive.

[0506] Comparative Example m2. A solid electrolyte membrane was prepared using a method essentially the same as that in Example 1, except that the type of binder, ethylene methyl acrylate, was changed to a block copolymer (block copolymer SEBS4055); the remaining operating steps were the same as in Example M1.

[0507] In this example, the contact angle of the block copolymer SEBS4055 is 155°. It is an ethylene-ethylene-butene-styrene block copolymer, which does not contain hydrophilic groups and is not an amphiphilic adhesive.

[0508] In each embodiment and comparative example, the drying time in the drying step after coating the electrolyte slurry can be adjusted to achieve thorough drying.

[0509] (II) Preparation of electrolyte electrode sheets (Preparation of electrolyte negative electrode sheets)

[0510] Examples J1 to J12: Solid electrolyte membranes are formed on a film-forming substrate using essentially the same method as in Examples M1 to M12, except that the film-forming substrate is changed to a negative electrode active material layer of a negative electrode sheet to obtain an electrolyte negative electrode sheet. The electrolyte electrode sheet consists of a negative electrode sheet and a solid electrolyte membrane located on the negative electrode active material layer, the solid electrolyte membrane corresponding to the first electrolyte layer.

[0511] The negative electrode sheet is prepared as follows: A silicon-carbon composite material (the negative electrode active material), polyvinylidene fluoride (PVDF) binder, and N-methylpyrrolidone (NMP) are uniformly mixed at a mass ratio of 97:3:100, coated onto both sides of a copper foil, dried, and cold-pressed to obtain the negative electrode sheet. The silicon-carbon composite material consists of a porous carbon matrix and nano-elemental silicon located within the pores of the porous carbon matrix, wherein the mass ratio of silicon to carbon is 1:1.

[0512] Example J13. An electrolyte negative electrode sheet was prepared using a method that was basically the same as that used in Example J1, except that the composition and preparation method of the electrolyte slurry were different.

[0513] Preparation of electrolyte slurry: Li6PS5Cl sulfide solid electrolyte powder, ethylene methyl acrylate binder and pseudotrimethylbenzene solvent were weighed in a ratio of 98:2:100 and mixed evenly in a degassing machine. The evenly mixed slurry was then coated on both sides of the negative electrode sheet with a coating thickness of 30μm and dried at 80℃ (720min in this example) to obtain the electrolyte negative electrode sheet.

[0514] The preparation method of the negative electrode sheet is the same as that in Example J1.

[0515] Comparative Examples j1 to j2 were prepared using essentially the same method as Comparative Examples m1 to m2, except that the electrolyte negative electrode sheets were prepared on both sides of the negative electrode active material of the negative electrode sheet by changing the coating substrate.

[0516] The preparation method of the negative electrode sheet is the same as that in Example J1.

[0517] (III) Solid-state battery fabrication

[0518] Examples 1 to 13 use electrolyte negative electrode sheets J1 to J13 to prepare all-solid-state batteries respectively, and Comparative Examples 1 and 2 use electrolyte negative electrode sheets j1 to j2 to prepare all-solid-state batteries respectively. The remaining operation steps are the same, and the drying time is allowed to be adjusted in the drying step.

[0519] The preparation method of solid-state batteries is as follows:

[0520] (1) Preparation of composite cathode materials

[0521] LiNi, the positive electrode active material 0.83 NiCo 0.12 Mn 0.05 O2, sulfide solid electrolyte Li6PS5Cl and conductive agent VGCF were weighed in a mass ratio of 70:27.5:2.5, ground in a mortar for 30 minutes to mix evenly, and used as a composite positive electrode material.

[0522] (2) Examples 1 to 13 use electrolyte electrodes J1 to J13 respectively, and Comparative Examples 1-2 use electrolyte negative electrodes j1-j2 respectively.

[0523] (3) Battery assembly:

[0524] The composite positive electrode material, solid electrolyte powder, and electrolyte negative electrode sheet are placed in an assembly mold in the following order to assemble a solid-state battery. The detailed steps are as follows: 100 mg of sulfide solid electrolyte Li6PS5Cl is weighed and added to the battery mold. The mold is pressurized at 350 MPa for 2 minutes to obtain a solid electrolyte sheet (providing a second electrolyte layer with a thickness of approximately 35 μm). Then, the composite positive electrode material is placed on one side of the solid electrolyte sheet, and the electrolyte negative electrode sheet is placed on the other side, ensuring that the first electrolyte layer in the electrolyte sheet contacts the solid electrolyte sheet (second electrolyte layer). The mixture is then pressed and assembled into an all-solid-state battery. The composite positive electrode material forms the positive electrode layer, the solid electrolyte film in the electrolyte negative electrode sheet provides the first electrolyte layer, and the negative electrode sheet in the electrolyte negative electrode sheet provides the negative electrode layer.

[0525] The types and amounts of binders used in the electrolyte slurry in each embodiment can also be found in Table 1.

[0526] Table 1.

[0527] (iv) Test and Analysis Methods

[0528] 1. Peel strength test of the first electrolyte layer

[0529] Instrument: Instron 3365 tensile testing machine.

[0530] The coating surface of the first electrolyte layer formed on the film-forming substrate (aluminum foil or negative electrode active material layer) is attached to a standard test plate, the peel angle is adjusted to 180°, and a tensile testing machine is used to peel it at 180°. The peel force values ​​of 50 points are obtained in the test distance of 50mm to 120mm and the average value is calculated as the test value of "peel strength" between the first electrolyte layer and the film-forming substrate.

[0531] The greater the peel strength, the higher the film-forming strength of the first electrolyte layer, and the greater the adhesion strength of the first electrolyte layer on the film-forming substrate, and the better the interfacial stability between the first electrolyte layer and the film-forming substrate.

[0532] The test results can be found in Table 2.

[0533] 2. Stability analysis of electrolyte slurry

[0534] The electrolyte slurry was stored in an inert atmosphere with water ≤0.01ppm and oxygen ≤0.01ppm for at least 48 hours. The stability of the slurry was observed, and whether sedimentation occurred was recorded. If sedimentation occurred during the observation period, the time of sedimentation was also recorded.

[0535] The longer the electrolyte slurry remains unsettled, the better its dispersibility and stability.

[0536] 3. Battery performance test

[0537] The battery was tested using a constant current charge-discharge mode at room temperature (25±3℃). The solid-state battery under test was first charged and discharged at a constant current of 0.1C for 3 cycles to obtain the initial capacity C1 of the battery. Then, it was charged and discharged at 0.33C for 200 cycles, and the cycle capacity retention rate of the battery was calculated. The capacity retention rate of the nth cycle = Cn / C1×100%, where n is a positive integer.

[0538] Battery testing window is 2.0V-4.3V vs. Li + / Li (Li potential, active ion is Li) + ), where 1C = 200mA / g.

[0539] The test results can be found in Table 3, "Capacity retention rate after 200 cycles (0.33C)".

[0540] Test Results and Analysis

[0541] In Examples M1-M13, an amphiphilic binder was introduced into the electrolyte slurry, and no sedimentation occurred within 48 hours. In Comparative Examples m1 and m2, no amphiphilic binder was used in the electrolyte slurry. Comparative Example m1's electrolyte slurry sedimented within 16 hours, and Comparative Example m2's electrolyte slurry sedimented within 12 hours.

[0542] By introducing an amphiphilic binder into the electrolyte slurry, the dispersibility and stability of the electrolyte slurry are significantly improved.

[0543] In the solid electrolyte membranes prepared in Examples M1-M13 and the electrolyte negative electrode sheets prepared in Examples J1-J13, the solid electrolyte membranes exhibit high peel strength relative to the film-forming substrate, the electrolyte negative electrode sheets demonstrate good mechanical properties, the first electrolyte layer exhibits high film-forming strength, and the first electrolyte layer possesses high adhesion strength relative to the negative electrode layer, thus providing a stable negative electrode layer / solid electrolyte layer interface. Furthermore, the all-solid-state batteries prepared in Examples 1-13 all demonstrate good cycle performance and high cycle capacity retention.

[0544] Examples M1-M13 also have a high initial discharge capacity.

[0545] Table 2.

[0546] Table 3.

[0547] The descriptions of the various implementation methods and embodiments above tend to emphasize the differences between them. Similarities or resemblances can be referenced interchangeably, and for the sake of brevity, they will not be repeated here. The technical features of the implementation methods and embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combinations of these technical features do not contradict each other, they should be considered within the scope of this specification.

[0548] It should be noted that this application is not limited to the above-described embodiments and examples. The above-described embodiments and examples are merely examples, and any embodiments and examples that have the same structure and achieve the same effect as the technical concept within the scope of this application are included in the technical scope of this application. The embodiments and examples described above only illustrate several embodiments and examples of this application, and although the descriptions are relatively detailed, they should not be construed as limiting the scope of the patent. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments or examples, and other ways of constructing embodiments or examples by combining some of the constituent elements of the embodiments or examples, are also included in the scope of this application without departing from the spirit of this application.

Claims

1. A solid-state battery, comprising a first electrode layer, a solid electrolyte layer, and a second electrode layer sequentially stacked thereon; wherein, The solid electrolyte layer includes a first electrolyte layer, which is located on the side of the solid electrolyte layer closer to the first electrode layer. The first electrolyte layer comprises a sulfide solid electrolyte and a first binder, wherein the first binder comprises an amphiphilic binder, and the amphiphilic binder comprises hydrophilic groups and lipophilic groups.

2. The solid-state battery according to claim 1, wherein, The contact angle of the amphiphilic adhesive is 20° to 90°, and can be selected as 30° to 90°; the contact angle value is the water contact angle value of the membrane material composed of the amphiphilic adhesive, and the test temperature is 23±2℃.

3. The solid-state battery according to claim 2, wherein, The contact angle of the amphiphilic adhesive is 45° to 90°, optionally 60° to 90°, and the test temperature is 23±2℃.

4. The solid-state battery according to any one of claims 1 to 3, wherein, The amphiphilic adhesive satisfies one or more of the following characteristics: The hydrophilic group includes one or more of the following: chlorine atom, ether bond, carboxyl group, -C(=O)-O-, and amide group; The lipophilic group includes C 1-8 alkyl.

5. The solid-state battery according to claim 4, wherein, The lipophilic group includes one or more of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl.

6. The solid-state battery according to any one of claims 1 to 5, wherein, The amphiphilic binder includes a carbon skeleton and side groups grafted onto the carbon skeleton, the side groups including the hydrophilic group and the lipophilic group.

7. The solid-state battery according to any one of claims 1 to 6, wherein, The amphiphilic adhesive includes amphiphilic rubber.

8. The solid-state battery according to claim 7, wherein, The contact angle of the amphiphilic rubber is 20° to 90°, optionally 30° to 90°, and further optionally 60° to 90°; The contact angle value is the water contact angle value of the membrane material composed of the amphiphilic adhesive, and the test temperature is 23±2℃.

9. The solid-state battery according to claim 7 or 8, wherein, The amphiphilic rubber satisfies one or more of the following characteristics: The elastic deformation of the amphiphilic rubber at 45°C is denoted as δ, where δ ≥ 200%. The elastic modulus of the amphiphilic rubber at 30°C is denoted as E, where E ≤ 100 MPa.

10. The solid-state battery according to claim 9, wherein, The amphiphilic rubber satisfies one or more of the following characteristics: The elastic deformation of the amphiphilic rubber at 45°C satisfies 450% ≤ δ ≤ 600%; The elastic modulus of the amphiphilic rubber at 30°C satisfies 50MPa≤E≤85MPa.

11. The solid-state battery according to any one of claims 7 to 10, wherein, The amphiphilic rubber includes amphiphilic acrylate rubber.

12. The solid-state battery according to claim 11, wherein, The amphiphilic acrylate rubbers include one or more of the following: chlorinated acrylate rubber, active chlorinated acrylate rubber, epoxy acrylate rubber, carboxyl acrylate rubber, double bond acrylate rubber, double crosslinked acrylate rubber, and ethylene methyl acrylate rubber.

13. The solid-state battery according to any one of claims 1 to 12, wherein, The first electrolyte layer satisfies one or more of the following characteristics: The amphiphilic binder has a weight percentage of 0.5 wt% to 15 wt% in the first electrolyte layer; The amphiphilic adhesive accounts for more than or equal to 10% of the weight of the first adhesive, and can be selected as 10% to 100%. The amphiphilic adhesive includes an amphiphilic rubber, and the weight percentage of the amphiphilic rubber in the first electrolyte layer is 0.5 wt% to 15 wt%. The amphiphilic adhesive includes amphiphilic rubber, and the weight percentage of the amphiphilic rubber in the first adhesive is greater than or equal to 10%, which can be selected as 10% to 100%. The first adhesive further includes one or more of the following adhesives: nitrile rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, natural rubber, polyvinylidene fluoride, etherified cellulose, polymethyl methacrylate, polyethylene oxide, and methyl vinyl silicone rubber; The thickness of the first electrolyte layer is 10 μm to 70 μm.

14. The solid-state battery according to claim 13, wherein, The first electrolyte layer satisfies one or more of the following characteristics: The weight percentage of the amphiphilic binder in the first electrolyte layer is 1 wt% to 15 wt%. The amphiphilic adhesive accounts for 30% to 100% of the weight of the first adhesive; The amphiphilic adhesive includes an amphiphilic rubber, and the weight percentage of the amphiphilic rubber in the first electrolyte layer is 1 wt% to 15 wt%. The amphiphilic adhesive includes amphiphilic rubber, and the weight percentage of the amphiphilic rubber in the first adhesive is 30wt% to 100wt%. The thickness of the first electrolyte layer is 20 μm to 50 μm.

15. The solid-state battery according to any one of claims 1 to 14, wherein, The first electrolyte layer satisfies one or more of the following characteristics: In the first electrolyte layer, the weight ratio of the amphiphilic binder to the sulfide solid electrolyte is (2-20):100; In the first electrolyte layer, the amphiphilic binder comprises amphiphilic rubber, and the weight ratio of the amphiphilic rubber to the sulfide solid electrolyte is (2-20):

100.

16. The solid-state battery according to any one of claims 1 to 15, wherein, The first electrolyte layer satisfies one or more of the following characteristics: In the first electrolyte layer, the weight ratio of the amphiphilic binder to the sulfide solid electrolyte is (2-18):100; In the first electrolyte layer, the amphiphilic binder comprises amphiphilic rubber, and the weight ratio of the amphiphilic rubber to the sulfide solid electrolyte is (2-18):

100.

17. The solid-state battery according to any one of claims 1 to 16, wherein, The sulfide solid electrolyte includes one or more of the following: LGPS type sulfide electrolyte, silver-germanium sulfide type sulfide electrolyte, lithium sulfide-phosphorus pentasulfide complex sulfide electrolyte, and thio-LISICON sulfide electrolyte.

18. The solid-state battery according to claim 17, wherein, The sulfide solid electrolyte includes L i6-x PS 5-x Cl 1+x , where 0≤x≤0.

9.

19. The solid-state battery according to any one of claims 1 to 18, wherein, The solid electrolyte layer further includes a second electrolyte layer, which is located between the second electrode layer and the first electrolyte layer; The second electrolyte layer includes a solid electrolyte and optionally includes a second binder.

20. The solid-state battery according to claim 19, wherein, The weight percentage of the amphiphilic adhesive in the second electrolyte layer is denoted as f12, and the weight percentage of the amphiphilic adhesive in the first electrolyte layer is denoted as f11. The second electrolyte layer satisfies one or more of the following characteristics: 0≤f12 <f11; The weight percentage f12 of the amphiphilic binder in the second electrolyte layer is 0 wt% to 5 wt%.

21. The solid-state battery according to claim 19 or 20, wherein it satisfies one or more of the following characteristics: The total thickness of the solid electrolyte layer is greater than 15 μm, and can be selected from 30 μm to 110 μm, and further selected from 40 μm to 90 μm; The thickness of the second electrolyte layer is greater than or equal to 10 μm, and can be selected as 20 μm to 45 μm, and more preferably 30 μm to 40 μm; The thickness of the second electrolyte layer is greater than the thickness of the first electrolyte layer; The binder content in the second electrolyte layer is lower than that in the first electrolyte layer, by weight percentage; The second adhesive has a weight percentage of 0 wt% to 5 wt% in the second electrolyte layer; The second electrolyte layer contains 95 wt% to 100 wt% solid electrolyte.

22. The solid-state battery according to any one of claims 1 to 21, wherein it satisfies one or more of the following characteristics: The first electrode layer is a negative electrode layer, and the second electrode layer is a positive electrode layer; optionally, the negative electrode layer includes a negative electrode current collector and a negative electrode active material layer located on at least one side of the negative electrode current collector, and the first electrolyte layer is located on the side of the negative electrode active material layer away from the negative electrode current collector; The solid-state battery is an all-solid-state battery.

23. A solid electrolyte membrane comprising a first electrolyte layer as defined in any one of claims 1 to 22.

24. An electrolyte electrode comprising an electrode body and a first electrolyte layer as defined in any one of claims 1 to 22, the first electrolyte layer being located on at least one side of the electrode body.

25. The electrolyte electrode according to claim 24, wherein, The electrolyte electrode sheet is an electrolyte negative electrode sheet, and the electrode body is a negative electrode body.

26. The electrolyte electrode according to claim 25, wherein, The negative electrode body includes a negative electrode current collector and a negative electrode active material layer located on at least one side of the negative electrode current collector, wherein the first electrolyte layer is located on the side of the negative electrode active material layer away from the negative electrode current collector; The negative electrode active material layer satisfies one or more of the following characteristics: The negative electrode active material layer includes a negative electrode binder; The negative electrode active material layer includes a negative electrode active substance, which includes a silicon-based material.

27. A method for preparing a solid-state battery, comprising the following steps: Preparation of electrolyte electrodes; wherein, The electrolyte electrode includes a first electrode layer and a first electrolyte layer located on at least one side of the first electrode layer; the first electrolyte layer includes a sulfide solid electrolyte and an amphiphilic binder, wherein the amphiphilic binder includes hydrophilic groups and lipophilic groups; A second electrode layer is formed on the side of the first electrolyte layer away from the first electrode layer.

28. The method for preparing a solid-state battery according to claim 27, wherein, The first electrolyte layer is formed on at least one side of the first electrode layer by coating and drying an electrolyte slurry; The electrolyte slurry comprises a solid electrolyte, the amphiphilic binder, and an organic solvent; the solid electrolyte comprises a sulfide solid electrolyte.

29. The method for preparing a solid-state battery according to claim 28, wherein, The electrolyte electrode is an electrolyte negative electrode, and the method for preparing the solid-state battery includes the following steps: The electrolyte slurry is coated onto at least one surface of the negative electrode sheet and dried to prepare the electrolyte negative electrode sheet; wherein the negative electrode sheet forms a negative electrode layer, and the dried electrolyte slurry forms the first electrolyte layer; A second electrolyte layer and a positive electrode layer are formed sequentially on the side of the first electrolyte layer away from the negative electrode layer.

30. The method for preparing a solid-state battery according to claim 28 or 29, wherein, The dielectric constant ε of the organic solvent in the electrolyte slurry satisfies: ε≤6.

5.

31. The method for preparing a solid-state battery according to claim 30, wherein, The organic solvent in the electrolyte slurry satisfies one or more of the following characteristics: The organic solvent includes one or more of low-polarity solvents and non-polar solvents; wherein, the dielectric constant ε1 of the low-polarity solvent satisfies: 2.6 < ε1 ≤ 6.5; and the dielectric constant ε2 of the non-polar solvent satisfies: ε2 ≤ 2.

6. The organic solvent includes substituted benzene, wherein the phenyl group in the substituted benzene is replaced by one or more substituents selected from the substituent group G, the substituent group G including: methyl, chlorine atom and methoxy; The organic solvent with a dielectric constant less than or equal to 6.5 is present in a weight percentage of 50 wt% to 100 wt%, optionally 70 wt% to 100 wt%. The organic solvent includes one or more of xylene, butyl butyrate, octyl butyrate, thallium, chlorobenzene, dimethyl carbonate, ethyl acetate, n-hexane, anisole, dibromomethane, triethyl phosphate, isopropyl ether, and benzyl acetate; optionally, the organic solvent includes one or more of p-xylene, pseudotrimethylbenzene, butyl butyrate, and octyl butyrate. The organic solvent in the electrolyte slurry is 30 wt% to 90 wt% by weight; optionally, the organic solvent in the electrolyte slurry is 40 wt% to 70 wt% by weight. The amphiphilic binder is present in the electrolyte slurry at a weight percentage of 0.5 wt% to 6 wt%, and may be 1 wt% to 6 wt%.

32. The method for preparing a solid-state battery according to any one of claims 27 to 31, wherein it satisfies one or more of the following characteristics: The electrolyte electrode sheet is the electrolyte electrode sheet according to any one of claims 24 to 26, and the first electrode layer includes a corresponding electrode body; The solid-state battery prepared is the solid-state battery according to any one of claims 1 to 22.

33. An electrical device comprising at least one of the following: a solid-state battery according to any one of claims 1 to 22; a solid electrolyte membrane according to claim 23; an electrolyte electrode according to any one of claims 24 to 26; and a solid-state battery prepared by the method of preparing a solid-state battery according to any one of claims 27 to 32.

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