All-solid-state battery negative electrode sheet
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WEICHAI POWER CO LTD
- Filing Date
- 2025-06-27
- Publication Date
- 2026-07-21
AI Technical Summary
All-solid-state batteries, lacking an electrolyte negative electrode, have weaker lithium-ion transport capabilities, resulting in poor rate performance and a higher susceptibility to short circuits.
Design an all-solid-state battery negative electrode sheet, including a current collector, a negative electrode coating and an electrolyte layer. The surface of the negative electrode coating has a porous structure, and the electrolyte layer fills the porous structure. The porous structure increases the contact area between the negative electrode coating and the electrolyte layer, thereby enhancing lithium-ion transport.
It improves the conductivity of the electrolyte-free negative electrode, enhances the rate performance of the all-solid-state battery, and avoids short-circuit problems.
Smart Images
Figure CN224537060U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of all-solid-state battery technology, and more specifically, to an all-solid-state battery negative electrode sheet. Background Technology
[0002] Solid-state batteries are batteries that use solid electrodes and solid electrolytes. Compared with traditional liquid lithium-ion batteries that use electrolytes, they have the advantage of increased energy storage capacity. At the same time, solid-state batteries have a higher power-to-weight ratio, making them an ideal battery for electric vehicles.
[0003] Currently, all-solid-state batteries, which lack an electrolyte anode and consist of active materials and binders, do not use sulfide electrolytes that are sensitive to humid air, effectively reducing the manufacturing cost of all-solid-state batteries. However, the lithium-ion transport capacity between particles is weak in all-solid-state batteries without an electrolyte anode, resulting in poor rate performance and a higher susceptibility to short circuits. Utility Model Content
[0004] In view of this, the purpose of this utility model is to provide a negative electrode for an all-solid-state battery, which improves the conductivity of the electrolyte-free negative electrode through electrode structure design, thereby improving the rate performance of the all-solid-state battery using the electrolyte-free negative electrode.
[0005] This utility model provides an all-solid-state battery negative electrode sheet, comprising:
[0006] current collector;
[0007] A negative electrode coating is disposed on at least one side surface of the current collector; the surface of the negative electrode coating away from the current collector has a plurality of pore structures.
[0008] An electrolyte layer is disposed on the surface of the negative electrode coating and filled with the plurality of porous structures.
[0009] Preferably, the negative electrode coating is an electrolyte-free negative electrode coating.
[0010] Preferably, the thickness of the negative electrode coating is 150μm to 300μm.
[0011] Preferably, the plurality of pore structures are evenly and uniformly arranged at equal intervals on the surface of the negative electrode coating.
[0012] Preferably, in the plurality of hole structures, the spacing between adjacent hole structures is less than the thickness of the negative electrode coating.
[0013] Preferably, the pore structure is a channel structure formed along the thickness direction of the negative electrode coating; the cross-sectional shape of the channel structure parallel to the negative electrode coating includes one or more of the following: circular, rectangular, and triangular.
[0014] Preferably, the pore diameter of the pore structure is <1000μm.
[0015] Preferably, the depth of the pore structure is more than 1 / 2 of the thickness of the negative electrode coating.
[0016] Preferably, the electrolyte layer includes a top electrolyte membrane covering the surface of the negative electrode coating and an insert filling the plurality of pore structures.
[0017] Preferably, the thickness of the top electrolyte membrane is 10 μm to 50 μm.
[0018] This invention provides an all-solid-state battery negative electrode sheet, comprising: a current collector; a negative electrode coating disposed on at least one surface of the current collector; the surface of the negative electrode coating away from the current collector having a plurality of porous structures; and an electrolyte layer disposed on the surface of the negative electrode coating and filling the plurality of porous structures. Compared with the prior art, the all-solid-state battery negative electrode sheet provided by this invention adopts a specific structure and connection relationship. Through the porous structure, the negative electrode coating and the electrolyte layer are in close contact, and the contact area between the two is effectively increased, thereby achieving better overall interaction. This reduces lithium-ion transport resistance, improves the conductivity of the electrolyte-free negative electrode, and thus improves the rate performance of the all-solid-state battery using the electrolyte-free negative electrode. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0020] Figure 1 This is a schematic diagram of the structure of the all-solid-state battery negative electrode sheet provided by this utility model.
[0021] Figure 2 A flowchart illustrating the fabrication process of the all-solid-state battery negative electrode sheet provided by this utility model.
[0022] Figure 3 Charge-discharge curves of an all-solid-state battery assembled without an electrolyte negative electrode at different rates are provided for comparison.
[0023] Figure 4 Charge-discharge curves of an all-solid-state battery assembled without an electrolyte negative electrode, provided in this embodiment of the utility model, at different rates.
[0024] The attached figures are labeled as follows:
[0025] 1. Current collector;
[0026] 2. Negative electrode coating;
[0027] 3. Electrolyte layer. Detailed Implementation
[0028] To enable those skilled in the art to better understand the present application, the technical solution of the present utility model will be clearly and completely described below in conjunction with the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.
[0029] In the description of this application, it should be understood that the terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0030] In the description of this application, "same chemical composition" should be interpreted broadly, that is, the main components of the two have the same chemical composition, or the two have substantially the same chemical composition, but may have errors or impurities within the acceptable range that can be understood by those skilled in the art.
[0031] In the description of this application, "A and / or B" can include any of the cases of A alone, B alone, or A and B, where A and B are merely examples and can be any technical feature connected by "and / or" in this application.
[0032] Unless otherwise stated, all technical terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. All patents and publications referenced in this application are incorporated herein by reference in their entirety. The terms "comprising" or "including" are open-ended expressions, meaning they include the contents specified in this application but do not exclude other contents.
[0033] Terminology Explanation:
[0034] Sulfide solid electrolytes: a type of solid electrolyte containing sulfur.
[0035] Active materials: Chemical substances that store lithium ions.
[0036] Currently, all-solid-state batteries, due to their higher energy storage capacity and power-to-weight ratio compared to traditional liquid lithium-ion batteries, have become the next-generation battery for electric vehicles and have broad development prospects. All-solid-state batteries, with their electrolyte-free anode composed of active materials and binders, do not use sulfide electrolytes sensitive to humid air during preparation. This broadens the range of anode coating preparation methods and solvent and binder choices. Furthermore, they do not require preparation in a dry environment, reducing environmental requirements and allowing for a reduction in electrolyte usage, thus effectively lowering the manufacturing and material costs of all-solid-state batteries. However, the lithium-ion transport capacity between particles in electrolyte-free anodes is weaker, resulting in poorer rate performance and a higher susceptibility to short-circuit problems in all-solid-state batteries.
[0037] To solve the above-mentioned technical problems, this utility model provides an all-solid-state battery negative electrode sheet, comprising:
[0038] current collector;
[0039] A negative electrode coating is disposed on at least one side surface of the current collector; the surface of the negative electrode coating away from the current collector has a plurality of pore structures.
[0040] An electrolyte layer is disposed on the surface of the negative electrode coating and filled with the plurality of porous structures.
[0041] See Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of the all-solid-state battery negative electrode sheet provided by this utility model; wherein, 1 is the current collector, 2 is the negative electrode coating, and 3 is the electrolyte layer.
[0042] In this invention, the all-solid-state battery negative electrode sheet includes a current collector, a negative electrode coating, and an electrolyte layer, preferably composed of a current collector, a negative electrode coating, and an electrolyte layer.
[0043] This invention does not impose any special restrictions on the type and source of the current collector; commercially available current collectors for all-solid-state battery negative electrode sheets, which are well-known to those skilled in the art, can be used. In one embodiment of this invention, the current collector is a copper current collector.
[0044] In this invention, the negative electrode coating is disposed on at least one side surface of the current collector; in one embodiment of this invention, the negative electrode coating is disposed on one side surface of the current collector.
[0045] In this invention, the negative electrode coating is preferably an electrolyte-free negative electrode coating. This invention uses an electrolyte-free negative electrode coating, which does not use sulfide electrolytes that are sensitive to humid air in its components. Therefore, it does not need to be prepared in a dry environment, which reduces environmental requirements. This broadens the range of negative electrode coating preparation methods and the selection of solvents and binders, and can reduce the amount of electrolyte used, thereby effectively reducing the manufacturing and material costs of all-solid-state batteries.
[0046] In this invention, the electrolyte-free negative electrode coating comprises an active material, a conductive agent, and a binder, preferably composed of the active material, the conductive agent, and the binder; wherein, the active material includes, but is not limited to, one or more of graphite, silicon-carbon, silicon-oxygen, and other alloy-type negative electrode materials; in one embodiment of this invention, the active material is a silicon-carbon negative electrode material; the conductive agent includes, but is not limited to, carbon black and / or carbon nanotubes; in one embodiment of this invention, the conductive agent is carbon black; the binder includes, but is not limited to, one or more of PAA, PAALi, PAANa, CMC, SBR, PVDF, and PTFE; in one embodiment of this invention, the binder is PAALi.
[0047] In this invention, the preferred mass ratio of the active material, conductive agent, and binder is (90-99):(0.5-1.5):(0.5-8.5).
[0048] This invention does not impose any special restrictions on the preparation method of the electrolyte-free negative electrode coating. It can be prepared by wet or dry processes well known to those skilled in the art. When using a wet process, water, N-methylpyrrolidone (NMP), etc., can be selected as solvents.
[0049] In one embodiment of this invention, a wet process is used to prepare an electrolyte-free negative electrode coating. First, the active material, conductive agent, and binder are dispersed in a solvent with a solid content of 50% to 60%, and a stable negative electrode slurry is formed by stirring. Then, the negative electrode slurry is uniformly coated on a current collector, and the wet film thickness is preferably 400 μm to 600 μm. Finally, the wet film is placed on a hot plate at 50°C to 70°C to dry thoroughly to obtain a dry film coating. The thickness of the dry film coating is preferably 180 μm to 380 μm. Since the adhesion of the inorganic electrolyte negative electrode is low after coating and drying, this invention improves the adhesion and cohesion by compacting the above-mentioned dry film coating. The compression rate of the dry film coating is controlled at 15% to 25%, resulting in the final electrolyte-free negative electrode coating.
[0050] Based on this, the thickness of the negative electrode coating is preferably 150μm to 300μm, and more preferably 200μm to 250μm.
[0051] In this invention, the surface of the negative electrode coating away from the current collector is provided with a plurality of pore structures; the plurality of pore structures are evenly and uniformly arranged at equal intervals on the surface of the negative electrode coating. Furthermore, the pore spacing between adjacent pore structures is equal; simultaneously, to ensure better lithium-ion transport performance, the pore spacing between adjacent pore structures is preferably smaller than the thickness of the negative electrode coating.
[0052] This invention uses a laser to etch the negative electrode coating, forming the plurality of pore structures. Preferably, the pore structures are channel structures formed along the thickness direction of the negative electrode coating. The cross-sectional shape of the channel structure parallel to the negative electrode coating preferably includes one or more of circles, rectangles, and triangles, more preferably circles, resulting in cylindrical channel structures. Furthermore, the high laser energy can carbonize the binder on the channel walls, reducing the resistance to lithium ion diffusion into the active material.
[0053] In this invention, the pore diameter of the pore structure is preferably <1000μm, more preferably <100μm.
[0054] In this invention, the depth of the pore structure is preferably more than 1 / 2 of the thickness of the negative electrode coating; in one embodiment of this invention, the depth of the pore structure is equal to the thickness of the negative electrode coating, forming a pore structure that penetrates the negative electrode coating.
[0055] In this invention, the electrolyte layer is disposed on the surface of the negative electrode coating and fills the plurality of pore structures; thus, it can be seen that the electrolyte layer includes a top electrolyte film covering the surface of the negative electrode coating and an insert filling the plurality of pore structures. Based on this, by setting the aforementioned plurality of specific pore structures, this invention enables the negative electrode coating and the electrolyte layer to be in close contact, effectively increasing the contact area between the electrolyte and the negative electrode active material, reducing lithium-ion transport resistance, and thereby improving the rate performance of the all-solid-state battery.
[0056] In this invention, the electrolyte layer comprises, but is not limited to, a series of materials with ion-conducting functions such as sulfide electrolytes, polymer electrolytes, oxides, and halides. It can be a single substance or a combination of multiple substances. In one embodiment of this invention, the electrolyte layer is made by sequentially coating, drying, and rolling an electrolyte slurry. The electrolyte slurry comprises lithium phosphorus sulfide chloride, polyisobutylene, and p-xylene solution, wherein the preferred mass ratio of lithium phosphorus sulfide chloride to polyisobutylene is (91-99):(1-9), and the preferred solid content of the electrolyte slurry is 30%-50%. The electrolyte layer can be uniformly coated onto the negative electrode coating by scraping, dip coating, aerosol coating, electrophoresis, or electroplating, filling the several pore structures, then dried at room temperature, and finally rolled to obtain an electrolyte layer with a top electrolyte membrane of the target thickness.
[0057] In this invention, the thickness of the top electrolyte membrane is preferably 10 μm to 50 μm, and more preferably 20 μm to 40 μm.
[0058] In this invention, the top electrolyte membrane and the insert filling the plurality of pore structures form an integral electrolyte layer, which is obtained by one-time molding without the need for an additional electrolyte membrane preparation process. When assembling the battery, the all-solid-state battery negative electrode sheet provided by this invention can be directly combined with the positive electrode, which reduces the manufacturing difficulty of solid-state batteries.
[0059] This invention provides an all-solid-state battery negative electrode sheet, comprising: a current collector; a negative electrode coating disposed on at least one surface of the current collector; the surface of the negative electrode coating away from the current collector having a plurality of porous structures; and an electrolyte layer disposed on the surface of the negative electrode coating and filling the plurality of porous structures. Compared with the prior art, the all-solid-state battery negative electrode sheet provided by this invention adopts a specific structure and connection relationship. Through the porous structure, the negative electrode coating and the electrolyte layer are in close contact, and the contact area between the two is effectively increased, thereby achieving better overall interaction. This reduces lithium-ion transport resistance, improves the conductivity of the electrolyte-free negative electrode, and thus improves the rate performance of the all-solid-state battery using the electrolyte-free negative electrode.
[0060] To further illustrate this utility model, the following embodiments will be described in detail.
[0061] Example
[0062] A schematic diagram of the all-solid-state battery negative electrode sheet provided in this embodiment of the invention is shown below. Figure 1 As shown, 1 represents the copper current collector, 2 represents the negative electrode coating, and 3 represents the electrolyte layer. The fabrication flowchart of this all-solid-state battery negative electrode is shown below. Figure 2 As shown, the specific steps are as follows:
[0063] (1) Disperse silicon-carbon anode material, conductive carbon black and PAALi in deionized water at a mass ratio of 95:1:4, with a solid content of 55%, and form a stable anode slurry by stirring.
[0064] (2) The negative electrode slurry obtained in step (1) is uniformly coated on the copper current collector, the wet film thickness is 500 μm, and the wet film is placed on a 60°C hot plate to dry fully to obtain a negative electrode sheet; the negative electrode sheet includes a copper current collector and a negative electrode coating disposed on the surface of the copper current collector, and the thickness of the negative electrode coating is 260 μm at this stage.
[0065] (3) The negative electrode sheet obtained in step (2) is subjected to roll forming. The coating thickness after roll forming is 80% of the original dry film thickness. Then, a laser is used to form holes in the negative electrode coating of the negative electrode sheet. The hole diameter is 2μm, the hole spacing is 100μm, and the hole depth is equal to the coating thickness to obtain a hole-formed negative electrode sheet.
[0066] (4) Lithium-phosphorus-sulfur-chlorine electrolyte (D50 = 800 nm) and polyisobutylene are uniformly dispersed in a p-xylene solution at a mass ratio of 95:5 to obtain an electrolyte slurry with a solid content of 40%.
[0067] (5) The electrolyte slurry obtained in step (4) is uniformly coated onto the porous negative electrode sheet obtained in step (3) by scraping. After drying at room temperature, a composite negative electrode sheet is obtained, wherein the thickness of the top electrolyte film is 100 μm.
[0068] (6) The composite negative electrode obtained in step (5) is subjected to roll forming. The thickness of the electrolyte membrane after roll forming is 30 μm, thus obtaining a solid-state battery negative electrode, i.e., a non-electrolyte negative electrode with a porous structure.
[0069] Comparative Example
[0070] The preparation method provided in the examples is used, except that no pores are formed; a solid-state battery negative electrode sheet is obtained, that is, a conventional electrolyte-free negative electrode sheet.
[0071] Performance testing:
[0072] The all-solid-state battery negative electrode sheets obtained in the examples and comparative examples were cut into φ10 small circular pieces, and then combined with ternary positive electrode sheets to form all-solid-state batteries. The above all-solid-state batteries (mold batteries) were then placed in an oven at 55°C to test their rate performance.
[0073] See results Figures 3-4 As shown, Figure 3 The charge-discharge curves of a conventional all-solid-state battery assembled with a non-electrolyte negative electrode provided for comparison show that it experiences a short circuit during the 0.5C charge-discharge test. Figure 4 The charge-discharge curves of the all-solid-state battery assembled with a porous electrolyte-free negative electrode sheet provided in this embodiment of the present invention at different rates show that the battery charges and discharges normally under 1C conditions without short circuits. Therefore, it can be seen that the present invention can effectively improve the rate performance of the electrolyte-free negative electrode through the electrode sheet structure design.
[0074] In the foregoing description of this specification, references to terms such as "one embodiment," "another embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment is included in at least one embodiment of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples, without contradiction. Additionally, it should be noted that in this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.
[0075] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A negative electrode sheet for an all-solid-state battery, characterized in that, include: current collector; A negative electrode coating is disposed on at least one side surface of the current collector; the surface of the negative electrode coating away from the current collector has a plurality of pore structures. An electrolyte layer is disposed on the surface of the negative electrode coating and filled with the plurality of porous structures.
2. The all-solid-state battery negative electrode sheet according to claim 1, characterized in that, The negative electrode coating is an electrolyte-free negative electrode coating.
3. The all-solid-state battery negative electrode sheet according to claim 1, characterized in that, The thickness of the negative electrode coating is 150μm to 300μm.
4. The all-solid-state battery negative electrode sheet according to claim 1, characterized in that, The plurality of pore structures are evenly distributed at equal intervals on the surface of the negative electrode coating.
5. The all-solid-state battery negative electrode sheet according to claim 4, characterized in that, In the plurality of hole structures, the spacing between adjacent hole structures is less than the thickness of the negative electrode coating.
6. The all-solid-state battery negative electrode sheet according to claim 1, characterized in that, The pore structure is a channel structure formed along the thickness direction of the negative electrode coating; the cross-sectional shape of the channel structure parallel to the negative electrode coating includes one or more of the following: circular, rectangular, and triangular.
7. The all-solid-state battery negative electrode sheet according to claim 1, characterized in that, The pore size of the pore structure is <1000μm.
8. The all-solid-state battery negative electrode sheet according to claim 1, characterized in that, The depth of the pore structure is more than 1 / 2 of the thickness of the negative electrode coating.
9. The all-solid-state battery negative electrode sheet according to claim 1, characterized in that, The electrolyte layer includes a top electrolyte membrane covering the surface of the negative electrode coating and an insert filling the plurality of pore structures.
10. The all-solid-state battery negative electrode sheet according to claim 9, characterized in that, The thickness of the top electrolyte membrane is 10 μm to 50 μm.