Pole piece structure and manufacturing method thereof, battery cell structure and battery
By introducing a solid electrolyte slurry layer into the pole sheet structure of the lithium-ion battery, the safety hazards of lithium-ion batteries when thermal runaway is solved, and the safety and dynamic performance of the battery are improved.
Patent Information
- Application Number
- CN202510234914.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-28
- Publication Date
- 2025-05-30
AI Technical Summary
Lithium-ion batteries are prone to safety hazards such as ignition when thermal runaway occurs, mainly due to the combustion of electrolyte and isolation membrane.
An electrode sheet structure is adopted, which includes a current collector structure, an electrode slurry layer coated on the surface of the current collector structure, and a solid electrolyte slurry layer, in which a part of the solid electrolyte slurry in which a solid electrolyte slurry layer is penetrated into the electrode slurry layer.
By leveraging the safety and dynamic characteristics of solid electrolytes, the safety and dynamic performance of the battery can be improved, the safety hazards caused by thermal runaway are reduced, and the energy density and low-temperature performance of the battery are optimized.
Smart Images
Figure CN120072835A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of batteries, and in particular, to an electrode structure, a manufacturing method thereof, a battery cell structure, and a battery. Background Art
[0002] With the development of science and technology, batteries are more and more widely used. From portable electronic devices such as mobile phones, laptops, digital cameras, etc., to the field of new energy vehicles, and then to large-scale energy storage systems, batteries play an indispensable role. Currently, most batteries use lithium-ion batteries, but when lithium-ion batteries experience thermal runaway, they are prone to safety hazards such as catching fire. Summary of the Invention
[0003] In view of the above problems, this application provides an electrode structure, a manufacturing method thereof, a battery cell structure, and a battery. The specific solutions are as follows:
[0004] An electrode structure, comprising:
[0005] A current collector structure;
[0006] An electrode paste layer coated on the first surface of the current collector structure;
[0007] A solid electrolyte paste layer coated on the surface of the electrode paste layer;
[0008] Wherein, part of the solid electrolyte paste of the solid electrolyte paste layer penetrates into the electrode paste layer.
[0009] Optionally, the concentration or content of the solid electrolyte paste in the electrode paste layer decreases along the thickness direction;
[0010] And / or,
[0011] The weight ratio of the solid electrolyte paste to the electrode paste of the electrode paste layer is 0.9 to 1.2.
[0012] Optionally, the solid electrolyte paste includes a solid electrolyte of nanoparticles, a binder, and a solvent;
[0013] The weight percentage of the solid electrolyte in the solid electrolyte paste is 98% to 99%, and the weight percentage of the binder in the solid electrolyte paste is 1% to 2%;
[0014] And / or,
[0015] The concentration of the solid electrolyte paste is 0.5% to 80%.
[0016] Optionally, the concentration of the solid electrolyte paste is 5% to 10%;
[0017] And / or,
[0018] The solid electrolyte slurry layer completely or incompletely covers the electrode slurry layer.
[0019] A battery cell structure includes a positive electrode tab, a negative electrode tab, and a separator disposed between the positive electrode tab and the negative electrode tab;
[0020] Wherein, the tab structure of the positive electrode tab and / or the negative electrode tab includes:
[0021] A current collector structure;
[0022] An electrode slurry layer coated on a first surface of the current collector structure;
[0023] A solid electrolyte slurry layer coated on the electrode slurry layer;
[0024] Wherein, a part of the solid electrolyte slurry of the solid electrolyte slurry layer infiltrates into the electrode slurry layer.
[0025] Optionally, the positive electrode tab includes a first solid electrolyte slurry layer, and the negative electrode tab includes a second solid electrolyte slurry layer;
[0026] The separator is disposed between the first solid electrolyte slurry layer and the second solid electrolyte slurry layer;
[0027] And / or,
[0028] The first solid electrolyte slurry layer and the second solid electrolyte slurry layer have the same or different thicknesses.
[0029] Optionally, it further includes at least one of the following:
[0030] The concentration or content of the solid electrolyte slurry in the electrode slurry layer decreases along the thickness direction;
[0031] The weight ratio of the solid electrolyte slurry to the electrode slurry of the electrode slurry layer is 0.9 to 1.2;
[0032] The solid electrolyte slurry includes a solid electrolyte of nanoparticles, a binder, and a solvent. The weight percentage of the solid electrolyte in the solid electrolyte slurry is 98% to 99%, and the weight percentage of the binder in the solid electrolyte slurry is 1% to 2%;
[0033] The concentration of the solid electrolyte slurry is 0.5% to 80%.
[0034] Optionally, the binder in the first solid electrolyte slurry layer is different from the binder in the second solid electrolyte slurry layer;
[0035] And / or,
[0036] The solvent in the first solid electrolyte slurry layer is different from the solvent in the second solid electrolyte slurry layer;
[0037] And / or,
[0038] The concentration of the solid electrolyte slurry in the first solid electrolyte slurry layer is different from the concentration of the solid electrolyte slurry in the second solid electrolyte slurry layer.
[0039] A battery includes: a battery cell, an electrolyte, and a housing encapsulating the battery cell and the electrolyte. Wherein, the battery cell includes: a positive electrode plate, a negative electrode plate, and a separator disposed between the positive electrode plate and the negative electrode plate, and the positive electrode plate and the negative electrode plate are wound layer by layer in the same direction after being isolated by the separator to form the battery cell; wherein, the electrode plate structure of the positive electrode plate and / or the negative electrode plate includes:
[0040] A current collector structure;
[0041] An electrode slurry layer coated on the first surface of the current collector structure;
[0042] A solid electrolyte slurry layer coated on the electrode slurry layer;
[0043] Wherein, a part of the solid electrolyte slurry of the solid electrolyte slurry layer penetrates into the electrode slurry layer.
[0044] A method for manufacturing an electrode plate structure includes:
[0045] Coating an electrode slurry on the first surface of the current collector structure;
[0046] Coating a solid electrolyte slurry on the surface of the electrode slurry;
[0047] Drying the electrode slurry and the solid electrolyte slurry to obtain an electrode slurry layer coated on the first surface of the current collector structure and a solid electrolyte slurry layer coated on the surface of the electrode slurry layer, wherein a part of the solid electrolyte slurry of the solid electrolyte slurry layer penetrates into the electrode slurry layer. Description of the Drawings
[0048] In combination with the drawings and with reference to the following specific embodiments, the above and other features, advantages, and aspects of the embodiments of the present disclosure will become more apparent. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the original components and elements are not necessarily drawn to scale.
[0049] Figure 1 It is a schematic structural diagram of an electrode plate structure provided by the present application;
[0050] Figure 2 Structural schematic diagram of a battery cell structure provided by this application;
[0051] Figure 3 Structural schematic diagram of a battery cell in a battery provided by this application;
[0052] Figure 4 Flowchart of a manufacturing method of a pole piece structure provided by this application;
[0053] Figure 5 Flowchart of a manufacturing method of a battery provided by this application. Detailed implementation manners
[0054] Next, the embodiments in this application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.
[0055] Without departing from the spirit or scope of this application, various modifications and variations can be made in this application, which will be obvious to those skilled in the art. Therefore, this application is intended to cover the modifications and variations of this application that fall within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the implementation manners provided in the embodiments of this application can be combined with each other without conflict.
[0056] To make the above objects, features, and advantages of this application more obvious and understandable, the following further detailed description of this application will be given in conjunction with the accompanying drawings and specific implementation manners.
[0057] As described in the background art section, when a lithium-ion battery undergoes thermal runaway, it is prone to safety hazards such as catching fire.
[0058] Specifically, a lithium-ion battery usually consists of a positive electrode, a negative electrode, a separator, an electrolyte, and a housing. Among them, the main component of the electrolyte is an organic solvent, and the main component of the separator is an organic polymer membrane. Therefore, when a lithium-ion battery undergoes thermal runaway, the electrolyte and the separator are prone to combustion, resulting in safety hazards such as battery fire caused by the combustion of the electrolyte and the separator in the lithium-ion battery.
[0059] Based on the safety and kinetic characteristics of solid electrolytes, in order to improve the safety of batteries, the industry has proposed that the separator and / or electrolyte in lithium-ion batteries can be replaced with solid electrolytes, thereby reducing safety incidents caused by the combustion of the separator and / or electrolyte during battery thermal runaway. However, the interfacial stability between the solid electrolyte and the electrode sheet is poor, and mass production cannot be achieved in the industry. If a certain amount of solid electrolyte is added to the traditional structure of a lithium-ion battery to form a semi-solid battery, it helps to improve the interfacial stability between the solid electrolyte and the electrode sheet in the traditional structure, but it will affect the energy density of the battery.
[0060] In view of this, an embodiment of the present application provides an electrode sheet structure, as Figure 1 shown, including:
[0061] A current collector structure 10;
[0062] An electrode paste layer 20 coated on the first surface of the current collector structure 10;
[0063] A solid electrolyte paste layer 30 coated on the surface of the electrode paste layer 20;
[0064] Wherein, a part of the solid electrolyte paste of the solid electrolyte paste layer 30 penetrates into the electrode paste layer 20.
[0065] The electrode sheet structure provided by the embodiment of the present application not only includes a current collector structure and an electrode paste layer coated on the first surface of the current collector structure, but also includes a solid electrolyte paste layer coated on the surface of the electrode paste layer, so that the safety and kinetic performance of the battery applied by the electrode sheet structure can be improved by using the safety and kinetic performance of the solid electrolyte paste layer.
[0066] Moreover, in the electrode sheet structure provided by the embodiment of the present application, a part of the solid electrolyte paste of the solid electrolyte paste layer penetrates into the electrode paste layer, so as to change the performance of some regions in the electrode paste layer, reduce the change amplitude of the kinetic characteristics of the electrode sheet structure on the surface of the electrode paste layer far from the current collector structure side, thereby further optimizing the kinetic performance of the electrode sheet structure, and further optimizing the kinetic performance of the battery applied by the electrode sheet structure.
[0067] Optionally, in an embodiment of the present application, the electrode sheet structure is the electrode sheet structure of a positive electrode, and the current collector structure can be aluminum foil; the electrode sheet structure is the electrode sheet structure of a negative electrode, and the current collector can be copper foil. The present application does not make any limitations on this, and it depends on the specific situation.
[0068] Optionally, based on the above embodiments, in an embodiment of the present application, the concentration or content of the solid electrolyte slurry in the electrode slurry layer decreases along the thickness direction, that is, the concentration or content of the solid electrolyte slurry in the electrode slurry layer gradually decreases in the direction away from the current collector structure, so as to form a solid electrolyte slurry with a gradient change in content in the electrode slurry layer, so that the kinetic characteristics of the electrode structure change in a gradient manner in the direction away from the current collector structure, thereby further optimizing the kinetic performance of the electrode structure, and finally optimizing the kinetic performance of the battery to which the electrode structure is applied.
[0069] It should be noted that in the electrode structure, the weight ratio of the solid electrolyte slurry layer to the electrode slurry layer will determine the thickness of the part of the solid electrolyte slurry layer located on the surface of the electrode slurry layer and the depth of penetration of the solid electrolyte slurry layer into the electrode slurry layer. Specifically, the smaller the weight ratio of the solid electrolyte slurry layer to the electrode slurry layer, the smaller the thickness of the part of the solid electrolyte slurry layer located on the surface of the electrode slurry layer, and the smaller the depth of penetration of the solid electrolyte slurry layer into the electrode slurry layer, the smaller the energy density loss of the electrode structure, and the weaker the improvement effect of the kinetic performance of the electrode structure; on the contrary, the larger the weight ratio of the solid electrolyte slurry layer to the electrode slurry layer, the larger the thickness of the part of the solid electrolyte slurry layer located on the surface of the electrode slurry layer, and the larger the depth of penetration of the solid electrolyte slurry layer into the electrode slurry layer, the larger the energy density loss of the electrode structure, the better the improvement effect of the kinetic performance of the electrode structure, and the stronger the stability of the contact surface between the surface of the electrode slurry layer away from the current collector structure and the solid electrolyte slurry layer.
[0070] Optionally, based on any of the above embodiments, in an embodiment of the present application, the weight ratio of the solid electrolyte slurry to the electrode slurry of the electrode slurry layer is 0.9 to 1.2 to balance the kinetic performance and energy density of the electrode structure. Optionally, in an embodiment of the present application, the weight ratio of the solid electrolyte slurry to the electrode slurry of the electrode slurry layer is 1 to 1.1 to further balance the kinetic performance and energy density of the electrode structure. However, the present application does not limit this, and it depends on the specific situation.
[0071] Based on any of the above embodiments, in a specific embodiment of the present application, the solid electrolyte slurry includes a solid electrolyte of nanoparticles, a binder, and a solvent, and the solid electrolyte slurry is obtained by uniformly mixing the solid electrolyte of nanoparticles, the binder, and the solvent. It should be noted that in this embodiment, the solid electrolyte is a solid electrolyte of nanoparticles with a relatively small size, so that when the solid electrolyte slurry infiltrates into the electrode slurry layer, it can fill the voids in the electrode slurry layer and have a relatively small impact on the volume of the electrode slurry layer. Furthermore, on the premise that the thickness of the electrode structure remains unchanged, the energy loss of the electrode structure is reduced, and finally the energy loss of the battery to which the electrode structure is applied is reduced.
[0072] Optionally, in an embodiment of the present application, the solid electrolyte of nanoparticles can be selected as LATP (Lanthanum Titanium Aluminum Phosphate) to reduce the cost of the electrode structure; the binder can be selected as a binder with the same electrical property according to the electrode characteristics of the electrode slurry layer in the actual electrode structure. For example, if the electrical property of the electrode slurry layer is positive, the binder can be selected as PVDF (Polyvinylidene Fluoride), and if the electrode characteristics of the electrode slurry layer are negative, the binder can be selected as CMC (Carboxymethyl Cellulose). However, the present application does not limit this, and it depends on the specific situation.
[0073] It should be noted that in this embodiment, the ratio of the solid electrolyte to the binder will affect the bonding degree of the solid electrolyte in the solid electrolyte slurry. Specifically, if the ratio of the solid electrolyte to the binder is relatively large, the improvement effect of the kinetic performance of the electrode structure is reduced, but the solid electrolyte is more likely to adhere near the active particles in the electrode slurry layer and will not fall off from the active particles or from the electrode structure due to the volume expansion or contraction of the active particles in the electrode slurry layer during the cycling process; if the ratio of the solid electrolyte to the binder is relatively small, the improvement effect of the kinetic performance of the electrode structure is more significant, but the solid electrolyte is more likely to fall off from the active particles or from the electrode structure due to the volume expansion or contraction of the active particles in the electrode slurry layer during the cycling process, or even cause the separation of the solid electrolyte slurry layer from the electrode structure, resulting in the problem that the kinetic performance of the electrode structure is significantly improved in the early stage and the improvement of the kinetic performance is reduced in the later stage during the use of the battery to which the electrode structure is applied.
[0074] Therefore, in an embodiment of the present application, to ensure the consistency of the kinetics in the early and late stages during the use of the battery to which the electrode structure is applied, the weight percentage of the solid electrolyte in the solid electrolyte slurry is 98% - 99%, and the weight percentage of the binder in the solid electrolyte slurry is 1% - 2%, so as to take into account the improvement of the kinetics performance in the early stage and the improvement of the kinetics performance in the late stage during the use of the battery to which the electrode structure is applied.
[0075] Based on any of the above embodiments, in an embodiment of the present application, the concentration of the solid electrolyte slurry is 0.5% - 80%, that is, in the solid electrolyte slurry formed by mixing the solid electrolyte, the binder and the solvent, the concentration value range of the solid electrolyte is 0.5% - 80%, so as to avoid that the concentration of the solid electrolyte is too large and the solid electrolyte in the solid electrolyte slurry layer cannot penetrate into the electrode slurry layer. At the same time, avoid that the concentration of the solid electrolyte is too low and no concentration gradient can be formed after penetrating into the electrode slurry layer. Optionally, in an embodiment of the present application, the concentration of the solid electrolyte slurry is 0.5% - 10%, that is, in the solid electrolyte slurry formed by mixing the solid electrolyte, the binder and the solvent, the concentration value range of the solid electrolyte is 0.5% - 10%, so that the solid electrolyte in the solid electrolyte slurry layer can penetrate into the electrode slurry layer more smoothly, and a concentration gradient is formed after the solid electrolyte penetrates into the electrode slurry layer. However, the present application does not limit this, and it depends on the specific situation.
[0076] It should be noted that in this embodiment, the solvent can be selected according to the electrode characteristics of the electrode slurry layer in the actual electrode structure. For example, if the electrical property of the electrode slurry layer is positive, the solvent can be NMP (N-Methylpyrrolidone), and if the electrode characteristic of the electrode slurry layer is negative, the solvent can be water or ethanol. However, the present application does not limit this, and it depends on the specific situation.
[0077] Based on any of the above embodiments, in an embodiment of the present application, the solid electrolyte slurry completely covers the electrode slurry layer, that is, the part of the solid electrolyte slurry located on the surface of the electrode slurry layer away from the current collector structure completely covers the surface of the electrode slurry layer away from the current collector structure, so as to form a lithium-ion conductor channel on the surface of the electrode slurry layer and improve the kinetic performance of the battery. However, the present application does not limit this. In other embodiments of the present application, the solid electrolyte slurry may not completely cover the electrode slurry layer, that is, the part of the solid electrolyte slurry located on the surface of the electrode slurry layer away from the current collector structure does not completely cover the surface of the electrode slurry layer away from the current collector structure, which depends on the specific situation.
[0078] In summary, the electrode structure provided by the embodiments of the present application not only includes a current collector structure and an electrode slurry layer coated on the first surface of the current collector structure, but also includes a solid electrolyte slurry layer coated on the surface of the electrode slurry layer. Part of the solid electrolyte slurry of the solid electrolyte slurry layer penetrates into the electrode slurry layer, so that the safety and kinetic characteristics of the solid electrolyte slurry can be utilized to improve the safety, kinetic performance and low-temperature performance of the battery to which the electrode structure is applied, and thus improve the user experience.
[0079] Correspondingly, an embodiment of the present application also provides a cell structure, as Figure 2 shown, the cell structure includes: a positive electrode tab 100, a negative electrode tab 200, and a separator 300 disposed between the positive electrode tab 100 and the negative electrode tab 200;
[0080] Wherein, the electrode structure of the positive electrode tab 100 and / or the negative electrode tab 200 includes:
[0081] A current collector structure;
[0082] An electrode slurry layer coated on the first surface of the current collector structure;
[0083] A solid electrolyte slurry layer coated on the surface of the electrode slurry layer;
[0084] Wherein, part of the solid electrolyte slurry of the solid electrolyte slurry layer penetrates into the electrode slurry layer.
[0085] Optionally, in an embodiment of the present application, continue as Figure 2As shown, the electrode structure of the positive electrode sheet 100 includes: a current collector structure 101, an electrode paste layer 102, and a solid electrolyte paste layer 103. Among them, a part of the solid electrolyte paste of the solid electrolyte paste layer 103 penetrates into the electrode paste layer 102, so as to improve the safety and kinetic performance of the positive electrode sheet 100, and improve the safety and kinetic performance of the battery cell structure.
[0086] In another embodiment of the present application, continue as Figure 2 As shown, the electrode structure of the negative electrode sheet 200 includes: a current collector structure 201, an electrode paste layer 202, and a solid electrolyte paste layer 203. Among them, a part of the solid electrolyte paste of the solid electrolyte paste layer 203 penetrates into the electrode paste layer 202, so as to improve the safety and kinetic performance of the negative electrode sheet 200, and improve the safety and kinetic performance of the battery cell structure.
[0087] In yet another embodiment of the present application, the electrode structure of the positive electrode sheet includes: a current collector structure, an electrode paste layer, and a solid electrolyte paste layer. Among them, a part of the solid electrolyte paste of the solid electrolyte paste layer penetrates into the electrode paste layer. And the electrode structure of the negative electrode sheet includes: a current collector structure, an electrode paste layer, and a solid electrolyte paste layer. Among them, a part of the solid electrolyte paste of the solid electrolyte paste layer penetrates into the electrode paste layer, so as to improve the safety and kinetic performance of the battery cell structure by simultaneously improving the safety and kinetic performance of the positive electrode sheet and the negative electrode sheet.
[0088] Next, taking the electrode structures of the positive electrode sheet and the negative electrode sheet both including a current collector structure, an electrode paste layer, and a solid electrolyte paste layer as an example, the battery cell structure provided by the embodiments of the present application will be further described.
[0089] Optionally, in an embodiment of the present application, the positive electrode sheet includes a first solid electrolyte paste layer, and the negative electrode sheet includes a second solid electrolyte paste layer; the separator is disposed between the first solid electrolyte paste layer and the second solid electrolyte paste layer. It should be noted that in this embodiment, the first solid electrolyte paste layer is the part of the solid electrolyte paste layer on the surface of the electrode paste layer in the positive electrode sheet, excluding the part that penetrates into the interior of the electrode paste layer; similarly, the second solid electrolyte paste layer is the part of the solid electrolyte paste layer on the surface of the electrode paste layer in the negative electrode sheet, including the part that penetrates into the interior of the electrode paste layer.
[0090] Based on any of the above embodiments, in an embodiment of the present application, the first solid electrolyte slurry layer and the second solid electrolyte slurry layer have the same thickness to improve the kinetic performance of the cell structure. However, the present application does not limit this. In other embodiments of the present application, the thicknesses of the first solid electrolyte slurry layer and the second solid electrolyte slurry layer may also be different, depending on the specific situation.
[0091] Optionally, based on the above embodiments, in an embodiment of the present application, the concentration or content of the solid electrolyte slurry in the electrode slurry layer decreases along the thickness direction, that is, the concentration or content of the solid electrolyte slurry in the electrode slurry layer gradually decreases along the direction away from the current collector structure, so as to form a solid electrolyte slurry with a gradient change in content in the electrode slurry layer, so that the kinetic characteristics of the electrode structure change in a gradient along the direction away from the current collector structure, thereby further optimizing the kinetic performance of the electrode structure, and ultimately optimizing the kinetic performance of the battery to which the electrode structure is applied.
[0092] It should be noted that in the electrode structure, the weight ratio of the solid electrolyte slurry layer to the electrode slurry layer will determine the thickness of the part of the solid electrolyte slurry layer located on the surface of the electrode slurry layer, as well as the depth and concentration gradient of the solid electrolyte slurry layer penetrating into the electrode slurry layer. Specifically, the smaller the weight ratio of the solid electrolyte slurry layer to the electrode slurry layer, the smaller the thickness of the part of the solid electrolyte slurry layer located on the surface of the electrode slurry layer, and the smaller the depth of the solid electrolyte slurry layer penetrating into the electrode slurry layer. The smaller the energy density loss of the electrode structure, the weaker the improvement effect of the kinetic performance of the electrode structure; on the contrary, the larger the weight ratio of the solid electrolyte slurry layer to the electrode slurry layer, the larger the thickness of the part of the solid electrolyte slurry layer located on the surface of the electrode slurry layer, and the larger the depth of the solid electrolyte slurry layer penetrating into the electrode slurry layer. The larger the energy density loss of the electrode structure, the better the improvement effect of the kinetic performance of the electrode structure, and the stronger the stability of the contact surface between the surface of the electrode slurry layer away from the current collector structure and the solid electrolyte slurry layer.
[0093] Optionally, based on any of the above embodiments, in an embodiment of the present application, the weight ratio of the solid electrolyte slurry to the electrode slurry in the electrode slurry layer is 0.9 to 1.2 to balance the kinetic performance and energy density of the electrode structure. Optionally, in an embodiment of the present application, the weight ratio of the solid electrolyte slurry to the electrode slurry in the electrode slurry layer is 1 to 1.1 to further balance the kinetic performance and energy density of the electrode structure. However, the present application does not limit this, depending on the specific situation.
[0094] Based on any of the above embodiments, in a specific embodiment of the present application, the solid electrolyte slurry includes a solid electrolyte of nanoparticles, a binder, and a solvent, and the solid electrolyte slurry is obtained by uniformly mixing the solid electrolyte of nanoparticles, the binder, and the solvent. It should be noted that in this embodiment, the solid electrolyte is a solid electrolyte of nanoparticles with a relatively small size. As a result, when the solid electrolyte slurry infiltrates into the electrode slurry layer, it can fill the voids in the electrode slurry layer, have a relatively small impact on the volume of the electrode slurry layer, and then, on the premise that the thickness of the electrode structure remains unchanged, reduce the energy loss of the electrode structure, and ultimately reduce the energy loss of the battery to which the electrode structure is applied.
[0095] It should be noted that in this embodiment, the ratio of the solid electrolyte to the binder will affect the bonding degree of the solid electrolyte in the solid electrolyte slurry. Specifically, if the ratio of the solid electrolyte to the binder is relatively large, the improvement effect of the kinetics of the electrode structure is reduced, but the solid electrolyte is more likely to adhere near the active particles in the electrode slurry layer and will not fall off from the active particles or from the electrode structure due to the volume expansion or contraction of the active particles in the electrode slurry layer during the cycle; if the ratio of the solid electrolyte to the binder is relatively small, the improvement effect of the kinetics of the electrode structure is more significant, but the solid electrolyte is more likely to fall off from the active particles or from the electrode structure due to the volume expansion or contraction of the active particles in the electrode slurry layer during the cycle, or even cause the separation of the solid electrolyte slurry layer and the electrode structure, resulting in the problem that the kinetics performance of the electrode structure is significantly improved in the early stage and the improvement of the kinetics performance is reduced in the later stage during the use of the battery to which the electrode structure is applied.
[0096] Therefore, in an embodiment of the present application, to ensure the consistency of the kinetics in the early and later stages during the use of the battery to which the electrode structure is applied, the weight percentage of the solid electrolyte in the solid electrolyte slurry is 98% - 99%, and the weight percentage of the binder in the solid electrolyte slurry is 1% - 2%, so as to take into account the improvement of the kinetics performance in the early stage and the improvement of the kinetics performance in the later stage during the use of the battery to which the electrode structure is applied.
[0097] Based on any of the above embodiments, in an embodiment of the present application, the concentration of the solid electrolyte slurry is 0.5% - 80%, that is, in the solid electrolyte slurry formed by mixing the solid electrolyte, the binder, and the solvent, the concentration range of the solid electrolyte is 0.5% - 80%, so as to avoid the excessive concentration of the solid electrolyte, where the solid electrolyte in the solid electrolyte slurry layer cannot penetrate into the electrode slurry layer. At the same time, it is to avoid the too low concentration of the solid electrolyte, which cannot form a concentration gradient after penetrating into the electrode slurry layer. Optionally, in an embodiment of the present application, the concentration of the solid electrolyte slurry is 0.5% - 10%, that is, in the solid electrolyte slurry formed by mixing the solid electrolyte, the binder, and the solvent, the concentration range of the solid electrolyte is 0.5% - 10%, so that the solid electrolyte in the solid electrolyte slurry layer can penetrate into the electrode slurry layer more smoothly, and a concentration gradient is formed after the solid electrolyte penetrates into the electrode slurry layer. However, the present application does not limit this, and it depends on the specific situation.
[0098] Based on any of the above embodiments, the binder in the first solid electrolyte slurry layer is different from the binder in the second solid electrolyte slurry layer. Optionally, in an embodiment of the present application, the binder in the first solid electrolyte slurry layer can be selected as PVDF (Polyvinylidene Fluoride); the binder in the second solid electrolyte slurry layer can be selected as CMC (CarboxymethylCellulose). However, the present application does not limit this, and it depends on the specific situation.
[0099] Optionally, in the above embodiments, the solid electrolyte of nanoparticles in the first solid electrolyte slurry layer can be selected as LATP (Lanthanum Titanium Aluminum Phosphate) to reduce the cost of the electrode structure; the solid electrolyte of nanoparticles in the second solid electrolyte slurry layer can also be selected as LATP (Lanthanum Titanium Aluminum Phosphate) to reduce the cost of the electrode structure. However, the present application does not limit this, and it depends on the specific situation.
[0100] Based on any of the above embodiments, in an embodiment of the present application, the solvent in the first solid-state electrolyte slurry layer is different from the solvent in the second solid-state electrolyte slurry layer. Optionally, the solvent in the first solid-state electrolyte slurry layer can be NMP (N-Methylpyrrolidone), and the solvent in the second solid-state electrolyte slurry layer can be water or ethanol. However, the present application does not limit this, and it depends on the specific situation.
[0101] Based on any of the above embodiments, in an embodiment of the present application, the concentration of the solid-state electrolyte slurry in the first solid-state electrolyte slurry layer is different from the concentration of the solid-state electrolyte slurry in the second solid-state electrolyte slurry layer, so as to set the corresponding concentration according to the balance point of the kinetic performance and energy density loss of the positive electrode plate and the negative electrode plate respectively, so as to further balance the kinetic performance and energy density loss of the cell structure. However, the present application does not limit this. In other embodiments of the present application, the concentration of the solid-state electrolyte slurry in the first solid-state electrolyte slurry layer may also be the same as the concentration of the solid-state electrolyte slurry in the second solid-state electrolyte slurry layer, depending on the specific situation.
[0102] In addition, an embodiment of the present application also provides a battery, which includes: a cell, an electrolyte, and a housing encapsulating the cell and the electrolyte, as Figure 3 shown, the cell includes: a positive electrode plate 100, a negative electrode plate 200, and a separator 300 disposed between the positive electrode plate 100 and the negative electrode plate 200. After the positive electrode plate 100 and the negative electrode plate 200 are isolated by the separator 300, they are wound layer by layer in the same direction to form the cell; wherein, the electrode plate structure of the positive electrode plate 100 and / or the negative electrode plate 200 includes:
[0103] A current collector structure;
[0104] An electrode slurry layer coated on the first surface of the current collector structure;
[0105] A solid-state electrolyte slurry layer coated on the surface of the electrode slurry layer;
[0106] Among them, a part of the solid-state electrolyte slurry in the solid-state electrolyte slurry layer penetrates into the electrode slurry layer.
[0107] Since the relevant content of the electrode plate structure has been described in the above embodiments, it will not be repeated here.
[0108] In the battery provided by the embodiment of the present application, the positive electrode sheet and / or the negative electrode sheet not only include a current collector structure and an electrode paste layer coated on the first surface of the current collector structure, but also include a solid electrolyte paste layer coated on the surface of the electrode paste layer. Part of the solid electrolyte paste of the solid electrolyte paste layer penetrates into the electrode paste layer, so that the safety and kinetic characteristics of the solid electrolyte paste can be utilized to improve the safety, kinetic performance and low-temperature performance of the battery, thereby improving the user experience.
[0109] In addition, the battery provided by the embodiment of the present application can also effectively reduce the amount of liquid electrolyte in the battery and improve the needle penetration rate by increasing the thickness of the solid electrolyte paste layer, further improving the safety.
[0110] In addition, the embodiment of the present application also provides a manufacturing method of a pole piece structure, as Figure 4 shown, the manufacturing method includes:
[0111] S1: Coating an electrode paste on the first surface of the current collector structure;
[0112] S2: Coating a solid electrolyte paste on the surface of the electrode paste;
[0113] S3: Drying the electrode paste and the solid electrolyte paste to obtain an electrode paste layer coated on the first surface of the current collector structure and a solid electrolyte paste layer coated on the surface of the electrode paste layer, wherein part of the solid electrolyte paste of the solid electrolyte paste layer penetrates into the electrode paste layer.
[0114] Specifically, in an embodiment of the present application, a double-layer coating process is adopted to coat an electrode paste and a solid electrolyte paste on the first surface of the current collector structure, so as to coat the electrode paste on the first surface of the current collector structure and coat the solid electrolyte paste on the surface of the electrode paste. However, the present application does not limit this, and it depends on the specific situation.
[0115] It should be noted that the particle sizes of the electrode paste particles and the solid electrolyte paste particles are different. Therefore, during the drying process of the electrode paste and the solid electrolyte paste, the solid electrolyte paste can sink from the surface of the electrode paste into the interior of the electrode paste. It should also be noted that the drying time and drying temperature of the electrode paste and the solid electrolyte paste will affect the thickness of the part of the solid electrolyte paste located on the surface of the electrode paste, as well as the depth and concentration gradient of the solid electrolyte paste penetrating into the interior of the electrode paste.
[0116] Specifically, when the drying time is fixed, the higher the drying temperature, the faster the drying speed, the shorter the sedimentation time of the solid electrolyte slurry, and the shallower the concentration gradient of the part of the solid electrolyte slurry located in the electrode slurry; when the drying temperature is fixed, the longer the drying time, the longer the sedimentation time of the solid electrolyte slurry, and the deeper the concentration gradient of the part of the solid electrolyte slurry located in the electrode slurry.
[0117] Optionally, in an embodiment of the present application, the solid electrolyte is a solid electrolyte in the form of nanoparticles. Drying the electrode slurry and the solid electrolyte slurry includes: drying the electrode slurry and the solid electrolyte slurry for a first time at a first temperature, where the first temperature ranges from 80°C to 120°C, and the first time ranges from 10 h to 48 h, so as to balance the concentration gradient structure of the part of the solid electrolyte slurry inside the electrode slurry and the homogeneous structure of the part of the solid electrolyte slurry on the surface of the electrode slurry, and build a laterally uniformly distributed but longitudinally concentration-gradient-distributed ion conduction path in the electrode slurry layer, thereby improving the kinetic performance of the electrode structure.
[0118] It should be noted that during the production process of the electrode structure, the weight ratio of the solid electrolyte slurry to the electrode slurry will determine the thickness of the part of the solid electrolyte slurry layer located on the surface of the electrode slurry layer and the depth of penetration of the solid electrolyte slurry layer into the electrode slurry layer. Specifically, the smaller the weight ratio of the solid electrolyte slurry to the electrode slurry, the smaller the thickness of the part of the solid electrolyte slurry located on the surface of the electrode slurry layer, and the smaller the depth of penetration of the solid electrolyte slurry into the electrode slurry layer. The smaller the energy density loss of the electrode structure, and the weaker the improvement effect on the kinetic performance of the electrode structure; conversely, the larger the weight ratio of the solid electrolyte slurry to the electrode slurry, the larger the thickness of the part of the solid electrolyte slurry layer located on the surface of the electrode slurry layer, and the larger the depth of penetration of the solid electrolyte slurry into the electrode slurry layer. The larger the energy density loss of the electrode structure, the better the improvement effect on the kinetic performance of the electrode structure, and the stronger the stability of the contact surface between the side surface of the electrode slurry layer away from the current collector structure and the solid electrolyte slurry layer.
[0119] Therefore, based on any of the above embodiments, in an embodiment of the present application, coating the solid electrolyte slurry on the surface of the electrode slurry includes coating the solid electrolyte slurry on the surface of the electrode slurry according to a preset ratio, where the preset ratio refers to the weight ratio of the solid electrolyte slurry to the electrode slurry in the electrode slurry layer, and the value range of the preset ratio is 0.9 to 1.2 to balance the kinetic performance and energy density of the electrode structure. Optionally, in an embodiment of the present application, the weight ratio of the solid electrolyte slurry to the electrode slurry in the electrode slurry layer is 1 to 1.1 to further balance the kinetic performance and energy density of the electrode structure. However, the present application does not limit this, and it depends on the specific situation.
[0120] Based on any of the above embodiments, in an embodiment of the present application, the method further includes: selecting solid electrolyte particles at the nanoscale, adding a binder and a solvent to adjust into a slurry with a certain viscosity to obtain the solid electrolyte slurry.
[0121] It should be noted that in the solid electrolyte slurry, the ratio of the solid electrolyte to the binder will affect the adhesion of the solid electrolyte in the solid electrolyte slurry. Specifically, if the ratio of the solid electrolyte to the binder is large, the improvement effect of the kinetic performance of the electrode structure is reduced, but the solid electrolyte is more likely to adhere near the active particles in the electrode slurry layer and will not fall off from the active particles or from the electrode structure due to the volume expansion or contraction of the active particles in the electrode slurry layer during cycling; if the ratio of the solid electrolyte to the binder is small, the improvement effect of the kinetic performance of the electrode structure is more significant, but the solid electrolyte is more likely to fall off from the active particles or from the electrode structure due to the volume expansion or contraction of the active particles in the electrode slurry layer during cycling, or even cause the separation of the solid electrolyte slurry layer and the electrode structure, resulting in the problem that the kinetic performance of the electrode structure is significantly improved in the early stage and the improvement of the kinetic performance is reduced in the later stage during the use of the battery to which the electrode structure is applied.
[0122] Therefore, in an embodiment of the present application, to ensure the consistency of the kinetics in the early and late stages during the use of the battery to which the electrode structure is applied, the weight percentage of the solid electrolyte in the solid electrolyte slurry is 98% to 99%, and the weight percentage of the binder in the solid electrolyte slurry is 1% to 2% to take into account the improvement of the kinetic performance in the early stage and the improvement of the kinetic performance in the later stage during the use of the battery to which the electrode structure is applied.
[0123] Based on any of the above embodiments, in an embodiment of the present application, the concentration of the solid electrolyte slurry is 0.5% to 80%, that is, in the solid electrolyte slurry formed by mixing the solid electrolyte, the binder and the solvent, the concentration range of the solid electrolyte is 0.5% to 80%, so as to avoid that the concentration of the solid electrolyte is too large and the solid electrolyte in the solid electrolyte slurry layer cannot penetrate into the electrode slurry layer. At the same time, it is avoided that the concentration of the solid electrolyte is too low and no concentration gradient can be formed after penetrating into the electrode slurry layer. Optionally, in an embodiment of the present application, the concentration of the solid electrolyte slurry is 0.5% to 10%, that is, in the solid electrolyte slurry formed by mixing the solid electrolyte, the binder and the solvent, the concentration range of the solid electrolyte is 0.5% to 10%, so that the solid electrolyte in the solid electrolyte slurry layer can penetrate into the electrode slurry layer more smoothly, and a concentration gradient is formed after the solid electrolyte penetrates into the electrode slurry layer. However, the present application does not limit this, and it depends on the specific situation.
[0124] In summary, the pole piece structure manufactured by using the method for manufacturing a pole piece structure provided by the embodiments of the present application has high safety, good kinetic performance, and small energy loss. Moreover, the method for manufacturing a pole piece structure provided by the embodiments of the present application does not require the introduction of special equipment and can be realized by using the existing pole piece manufacturing process.
[0125] Correspondingly, an embodiment of the present application further provides a method for manufacturing a battery, as Figure 5 shown, including:
[0126] Manufacturing a positive pole piece and a negative pole piece;
[0127] After isolating the positive pole piece and the negative pole piece with a separator, winding them layer by layer in the same direction to form an electric core;
[0128] Encapsulating the electric core with a housing and injecting an electrolyte into the accommodation space of the housing to obtain the battery.
[0129] Optionally, in an embodiment of the present application, after isolating the positive pole piece and the negative pole piece with a separator and winding them layer by layer in the same direction to form an electric core, it includes:
[0130] First, after isolating the positive pole piece and the negative pole piece with a separator, a mixed pole piece is obtained, and the mixed pole piece formed by the positive pole piece, the negative pole piece and the separator is roll-pressed; then the mixed pole piece formed by the positive pole piece, the negative pole piece and the separator is slit into a plurality of pole piece units, and then each pole piece unit is wound layer by layer in the same direction to form an electric core.
[0131] Optionally, in an embodiment of the present application, encapsulating the battery cell with a housing and injecting electrolyte into the accommodation space of the housing to obtain the battery includes:
[0132] First, place the wound battery cell into the housing of the aluminum-plastic film; second, inject the electrolyte into the accommodation space formed by the housing through the opening of the housing; then, seal the opening of the housing to prevent electrolyte leakage and the influence of the external environment on the battery; then, perform a process of charging the battery with a small current to form a stable SEI film (solid electrolyte interface film) on the surface of the active material, thereby preventing the reduction reaction of solvent molecules on the electrode surface; finally, perform certain charge and discharge tests on the battery and calculate the capacity of the battery according to the test results, so as to determine it as different grades according to the capacity of the battery to meet the requirements of different application scenarios.
[0133] It should be noted that, in this embodiment, the positive electrode plate and / or the negative electrode plate can be manufactured by using the manufacturing method of the electrode plate structure provided in any of the above embodiments. Since the manufacturing method of the electrode plate structure has been described in the above embodiments, it will not be elaborated here.
[0134] Since the positive electrode plate and / or the negative electrode plate have good safety and kinetic performance and small energy density loss, therefore, the battery manufactured by using the battery manufacturing method provided in the embodiment of the present application has relatively high safety, good kinetic performance and small energy loss. Moreover, the battery manufacturing method provided in the embodiment of the present application does not require the introduction of special equipment and can be realized by using the existing battery manufacturing process.
[0135] In this specification, the various embodiments are described in a progressive, or parallel, or a combination of progressive and parallel manners. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.
[0136] It should be noted that in the description of this application, it should be understood that the descriptions of the drawings and embodiments are illustrative rather than restrictive. The same reference numerals throughout the embodiments of the specification identify the same structures. Additionally, for the sake of understanding and ease of description, the drawings may exaggerate the thickness of some layers, films, panels, regions, etc. It should also be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that an article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the article or device comprising the above element.
[0137] The above description of the disclosed embodiments enables those skilled in the art to implement or use this application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.
Claims
1. A pole piece structure, comprising: Current collector structure; an electrode slurry layer coated on a first surface of the current collector structure; A solid electrolyte slurry layer coated on the surface of the electrode slurry layer; Wherein, part of the solid electrolyte slurry of the solid electrolyte slurry layer is infiltrated into the electrode slurry layer.
2. The pole piece structure according to claim 1, wherein: The concentration or content of the solid electrolyte slurry in the electrode slurry layer decreases along the thickness direction; and / or, The weight ratio of the solid electrolyte slurry to the electrode slurry of the electrode slurry layer is 0.9 to 1.
2.
3. The pole piece structure according to claim 1 or 2, wherein: The solid electrolyte slurry includes a solid electrolyte of nanoparticles, a binder and a solvent; The weight proportion of the solid electrolyte in the solid electrolyte slurry is 98% to 99%, and the weight proportion of the adhesive in the solid electrolyte slurry is 1% to 2%; and / or, The concentration of the solid electrolyte slurry is 0.5% to 80%.
4. The pole piece structure according to claim 3, wherein: The concentration of the solid electrolyte slurry is 5% to 10%; and / or, The solid electrolyte slurry layer completely or incompletely covers the electrode slurry layer.
5. A battery cell structure, comprising a positive electrode sheet, a negative electrode sheet and a separator disposed between the positive electrode sheet and the negative electrode sheet; in, The electrode structure of the positive electrode sheet and / or the negative electrode sheet includes: Current collector structure; an electrode slurry layer coated on a first surface of the current collector structure; A solid electrolyte slurry layer coated on the electrode slurry layer; Wherein, part of the solid electrolyte slurry of the solid electrolyte slurry layer is infiltrated into the electrode slurry layer.
6. The battery cell structure according to claim 5, wherein: The positive electrode plate includes a first solid electrolyte slurry layer, and the negative electrode plate includes a second solid electrolyte slurry layer; The separator is disposed between the first solid electrolyte slurry layer and the second solid electrolyte slurry layer; and / or, The thickness of the first solid electrolyte slurry layer and the second solid electrolyte slurry layer are the same or different.
7. The battery cell structure according to claim 6, wherein: Also includes at least one of the following: The concentration or content of the solid electrolyte slurry in the electrode slurry layer decreases along the thickness direction; The weight ratio of the solid electrolyte slurry to the electrode slurry of the electrode slurry layer is 0.9 to 1.2; The solid electrolyte slurry comprises a solid electrolyte of nanoparticles, a binder and a solvent, wherein the weight proportion of the solid electrolyte in the solid electrolyte slurry is 98% to 99%, and the weight proportion of the binder in the solid electrolyte slurry is 1% to 2%; The concentration of the solid electrolyte slurry is 0.5% to 80%.
8. The battery core structure according to claim 6 or 7, wherein: The binder in the first solid electrolyte slurry layer is different from the binder in the second solid electrolyte slurry layer; and / or, The solvent in the first solid electrolyte slurry layer is different from the solvent in the second solid electrolyte slurry layer; and / or, The concentration of the solid electrolyte slurry in the first solid electrolyte slurry layer is different from the concentration of the solid electrolyte slurry in the second solid electrolyte slurry layer.
9. A battery comprising: A battery cell, an electrolyte, and a shell encapsulating the battery cell and the electrolyte, wherein the battery cell comprises: a positive electrode sheet, a negative electrode sheet, and a separator arranged between the positive electrode sheet and the negative electrode sheet, and the positive electrode sheet and the negative electrode sheet are separated by the separator and wound layer by layer in the same direction to form the battery cell; wherein the electrode sheet structure of the positive electrode sheet and / or the negative electrode sheet comprises: Current collector structure; an electrode slurry layer coated on a first surface of the current collector structure; A solid electrolyte slurry layer coated on the electrode slurry layer; Wherein, part of the solid electrolyte slurry of the solid electrolyte slurry layer is infiltrated into the electrode slurry layer.
10. A method for manufacturing a pole piece structure, comprising: coating an electrode slurry on a first surface of the current collector structure; Coating a solid electrolyte slurry on the surface of the electrode slurry; The electrode slurry and the solid electrolyte slurry are dried to obtain an electrode slurry layer coated on the first surface of the current collector structure and a solid electrolyte slurry layer coated on the surface of the electrode slurry layer, wherein a portion of the solid electrolyte slurry of the solid electrolyte slurry layer is infiltrated into the electrode slurry layer.