Method for manufacturing electrode member, electrode, and lithium secondary battery

Abstract

The present invention relates to a method for preparing an electrode member comprising a current collector layer, and an active material layer and a solid electrolyte layer on at least one side of the current collector layer, and an electrode and a lithium secondary battery comprising the electrode member obtained by the method, the method includes an active material layer forming step, a first press working step, a solid electrolyte layer introduction step, and a second press working step.

Description

Technical Field

[0001] This invention belongs to the field of new energy, specifically relating to a method for preparing an electrode component for a battery, an electrode including the prepared electrode component, and a secondary battery. More specifically, it relates to a method for preparing an electrode component for a lithium secondary battery, as well as the electrode and the lithium secondary battery. Background Technology

[0002] With the rapid development of new energy technologies, solid-state battery technology is also developing rapidly.

[0003] Solid-state batteries have stricter and more specific requirements for electrodes than traditional liquid lithium-ion batteries. This is mainly because they contain very little or no liquid electrolyte, requiring good solid-solid interface contact while ensuring high energy density and cycle stability.

[0004] In some cases, solid electrolytes cannot "wet" the electrodes like liquid electrolytes, and a dense structure is beneficial for reducing interfacial impedance. Therefore, the electrode should have a highly dense structure to reduce porosity and increase the contact area with the solid electrolyte.

[0005] Common methods for preparing electrodes are divided into dry and wet methods. The active material and the current collector can be pressed together by pressure rollers to obtain positive or negative electrode sheets.

[0006] Furthermore, to prevent pulverization, cracking, or detachment, electrode materials must be compatible with the volume changes of the solid electrolyte during charging and discharging. In addition to using active materials with low coefficients of expansion and appropriately adding elastic binders (such as PTFE and PVDF) to improve flexibility, integrated electrode components combining active materials and solid electrolytes have also been developed.

[0007] Furthermore, for integrated electrode components formed by current collectors, active materials, and solid electrolytes, the appearance of the electrode sheet is subject to high requirements during the processing of the solid electrolyte layer. For example, in order to prevent excessive roughness after electrode pressing or coating from causing local voids in the stacking or lamination, its surface must be smooth to avoid particle protrusions or detachment, ensuring tight bonding and low contact resistance.

[0008] In addition, for solid-state batteries, from the perspective of effectively improving the current transmission path, reducing internal resistance, and improving battery performance and safety, multi-tab or all-tab technologies are receiving increasing attention, especially for large cylindrical batteries, which have become a hot topic in research and design. Summary of the Invention

[0009] The problem the invention aims to solve

[0010] As mentioned above, integrated electrode components and multi-tab / all-tab designs are advantageous for solid-state batteries. In the manufacturing process, pressure processing techniques such as pressure rollers are typically used to laminate the metal foil, active material layer, and electrolyte layer.

[0011] In practical industrial applications, it has been found that to improve the interfacial performance between the active material layer and the solid electrolyte, it is necessary to control the smoothness of the interface between the active material layer or active material layer and the solid electrolyte layer. However, from the perspective of improving the tightness of the integrated structure, increasing the pressure during pressure processing makes it difficult to control the smoothness of the active material layer (especially the active material layer formed by slurry coating) during rolling due to the difference in their softness. In addition, from the design of multi-tab or full-tab, excessively high pressure on the electrode pressure processing area can also easily lead to wrinkling or irregular deformation in the tab area.

[0012] For example, in order to improve the integration effect, the electrode stack is subjected to high-pressure real-time rolling processing. Due to the inconsistent extension of different processing areas (current collector area and electrode tab area), it is easy to cause electrode tab wrinkles or bulging of active material area. This can easily lead to problems such as frequent strip breakage or uneven introduction of solid layer during solid layer introduction.

[0013] To address this issue, the applicant has developed a method to improve the appearance of electrode sheets and facilitate solid electrode processing. By performing step-by-step pressure processing and controlling the degree of compaction at each step, the method can ensure the flatness of the active material layer to improve its bonding with the electrolyte layer, and also reduce the difference in ductility between the pressure-processed and non-pressure-processed areas, thereby reducing electrode wrinkles in the manufacture of multi-tab / all-tab components.

[0014] Solution for solving the problem

[0015] The above-mentioned technical problems have been solved by implementing the following technical solutions:

[0016] This invention first provides a method for fabricating an electrode component, wherein the electrode component includes a current collector layer, an active material layer on at least one side of the current collector layer, and a solid electrolyte layer, the method comprising:

[0017] The steps include the formation of the active material layer, the first pressure processing step, the introduction of the solid electrolyte layer, and the second pressure processing step.

[0018] in,

[0019] In the step of forming the active material layer, the active material layer is formed on at least one side of the current collector layer.

[0020] In the first pressure processing step, the component with the active material layer is subjected to the first pressure processing, thereby giving the active material layer a first compaction density η1;

[0021] In the step of introducing the solid electrolyte layer, the solid electrolyte layer is formed on the surface of the active material layer of the component obtained by the first pressure processing;

[0022] In the second pressure processing step, the component with the introduced solid electrolyte layer is subjected to a second pressure processing, thereby imparting a second compaction density η2 to the active material layer.

[0023] Furthermore, the first compaction density η1 and the second compaction density η2 satisfy the following relationship:

[0024] η1=(82%~90%)·η2 (1)

[0025] Where η2 is the value of the electrode component directly assembled into the battery.

[0026] According to the aforementioned method, in the first pressure processing step, the total thickness of the current collector layer and the active material layer is d1, and in the second pressure processing step, the total thickness of the current collector layer and the active material layer is d3.

[0027] Wherein, d1 and d3 satisfy the following relationship:

[0028] d1=1.14~1.18d3 (2).

[0029] According to the aforementioned method, the current collector is a metal foil.

[0030] According to the aforementioned method, in the step of forming the active material layer, the active material layer is formed in the form of a slurry coating.

[0031] According to the aforementioned method, in the step of introducing the solid electrolyte layer, the thickness d2 of the solid electrolyte layer formed on the surface of the active material layer is 5~70μm.

[0032] According to the aforementioned method, in the second pressure processing step, the second pressure processing imparts a compaction density η3 of 0.82~1.60 g / (m³) to the solid electrolyte layer. 3 ·10 -6 ).

[0033] According to the aforementioned method, both the first pressure processing and the second pressure processing are performed using pressure rollers, the tension applied by the pressure rollers is 50~200N, and the tension applied by the pressure rollers for the first pressure processing is lower than the tension applied by the pressure rollers for the second pressure processing.

[0034] According to the aforementioned method, η2 includes the following cases: when the electrode component is a positive electrode component, η2' is 2.3~3.6 g / (m 3 ·10 -6 When the electrode component is a negative electrode component, the η2'' is 1.6~1.8 g / (m). 3 ·10 -6 ).

[0035] According to the aforementioned method, the solid electrolyte layer comprises an oxide solid electrolyte, a polymer solid electrolyte, or a mixture of solid electrolytes in any proportion thereof.

[0036] Furthermore, the present invention also provides an electrode, including a tab and an electrode component obtained by the above-described preparation method, wherein the tab and the electrode component are integrated.

[0037] Furthermore, the present invention also provides a lithium secondary battery, wherein it includes or uses the electrodes described above.

[0038] The aforementioned lithium secondary battery is used as a battery for energy storage systems or as a power battery.

[0039] The effects of the invention

[0040] By implementing the above technical solution, the present invention can achieve the following technical effects:

[0041] The electrode component processing method of the present invention enables the processed electrode component to have an improved appearance, which ultimately improves the cycle performance of the secondary battery.

[0042] In the processing technology of this invention, the active material slurry layer is first processed under initial pressure to 82%~90% of the required compaction level. The material area extension is not significant, avoiding bulging and uneven introduction of the solid layer. Simultaneously, it ensures consistency in the material area and the tab extension, preventing tab wrinkles and reducing the risk of breakage during solid electrolyte layer introduction. Furthermore, at this stage, the solid electrolyte layer has a higher hardness than the liquid slurry. After introducing the solid electrolyte layer, subsequent high-pressure rolling does not damage or crush the solid electrolyte layer, and it effectively compacts the active material slurry layer to the required level. This effectively solves a series of problems caused by poor appearance of the liquid electrode sheet under high-pressure compaction, leading to solid-state conduction. Attached Figure Description

[0043] Figure 1 A process flow diagram of the present invention

[0044] Figure 2 Surface morphology of the component in Embodiment 1 of the present invention

[0045] Figure 3 Surface morphology of the component in Embodiment 2 of the present invention

[0046] Figure 4 Surface morphology of the component in Embodiment 3 of the present invention

[0047] Figure 5 Surface morphology of the component in Comparative Example 1 of the present invention

[0048] Figure 6 Surface morphology of the component in Comparative Example 2 of the present invention Detailed Implementation

[0049] The present invention will now be described in detail. The descriptions of the technical features described below are based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0050] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0051] In this specification, the numerical range indicated by "above" or "below" refers to the numerical range that includes the stated number.

[0052] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0053] In this specification, the terms "optional" or "optional" are used to indicate the use or omission of certain substances, components, procedures, application conditions, etc.

[0054] In this instruction manual, "normal temperature" or "room temperature" refers to an indoor ambient temperature of "23±2℃".

[0055] All unit names used in this manual are international standard unit names, and unless otherwise stated, the "%" indicates weight or mass percentage.

[0056] In this specification, unless otherwise defined, the term "electrode" is used to refer to a stack of current collector and active material layer.

[0057] In the instruction manual, the term "requirement" refers to the meaning of "set value," which is the value of the final processing endpoint of the component, or the value of the component that meets the requirements of the next stage of use.

[0058] In this specification, the terms "substantially" and "essentially" are used to indicate that the standard deviation from the theoretical model, theoretical data, or target data is within a range of 2%, preferably 1%, and more preferably 0.8%.

[0059] In this specification, the terms “comprising” and / or “including” are used to indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0060] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "implementation," etc., refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to that embodiment, which are included in at least one of the embodiments described herein and may or may not be present in other embodiments. Furthermore, it should be understood that these elements may be combined in any suitable manner in various embodiments.

[0061] This invention primarily provides a method for fabricating an electrode component, as well as an electrode and a lithium secondary battery comprising the electrode component obtained by this method. The electrode component includes a current collector layer, an active material layer on at least one side of the current collector layer, and a solid electrolyte layer.

[0062] This invention is mainly based on the following insights:

[0063] Existing electrode laminate processing typically involves laminating a slurry layer and an electrolyte layer. However, during roll extrusion, the difference in hardness between the slurry and electrolyte layers can lead to uneven slurry layer distribution, resulting in blistering or poor interfacial bonding between the slurry and electrolyte layers. Furthermore, in integrated tab manufacturing processes, the portion used to form the tab is the exposed current collector. The tension experienced by this portion during extrusion differs from the extrusion tension experienced by the current collector in the slurry / electrolyte layer region. Consequently, wrinkles may form in the exposed current collector area, hindering the formation of multi-tab and full-tab structures. Therefore, this invention improves the lamination process by first applying a first pressure to compact the active material slurry layer to 82%–90% of its required compaction level. While ensuring a certain strength in the slurry layer, the electrolyte layer is then further formed. This reduces the hardness difference between the two layers and avoids the inhomogeneity that occurs when excessive pressure is applied to the slurry layer. As a result, during the second pressure processing, the slurry and electrolyte layers exhibit improved interfacial bonding, preventing damage to the electrolyte layer. In addition, the two-step extrusion process can also alleviate the difference in elongation caused by different areas of the current collector metal foil, thereby improving the convenience of electrode processing.

[0064] [First aspect]

[0065] In a first aspect, the present invention provides a method for preparing an electrode component, wherein the electrode component includes a current collector layer, an active material layer and a solid electrolyte layer on at least one side of the current collector layer.

[0066] The method includes: a step of forming an active material layer, a step of first pressure processing, a step of introducing a solid electrolyte layer, and a step of second pressure processing.

[0067] (Current collector layer)

[0068] The current collector of the present invention is not particularly limited in principle and can use various commonly used metals. In some specific embodiments, the current collector for the positive electrode can be aluminum and the current collector for the negative electrode can be copper.

[0069] There are no particular restrictions on the thickness of the current collector; aluminum or copper foil of the same thickness as commonly used electrodes can be used.

[0070] In some preferred embodiments, the current collector can be cleaned or surface treated before use.

[0071] In some preferred embodiments of the present invention, the current collector layer can be divided into a covered region and an exposed region. The covered region is used to sequentially form an active material layer and a solid electrolyte layer, while at least a portion of the exposed region can be used to form tabs.

[0072] (Active substance layer)

[0073] The active material layer of the present invention can be divided into a positive electrode active material layer and a negative electrode active material layer, both of which can be formed in the form of a slurry.

[0074] There are no particular restrictions on the positive electrode active layer in principle, and the composition commonly used in the art can be used, which may include positive electrode active material, binder, and optional conductive agent, additive, etc.

[0075] There are no particular restrictions on the positive electrode active material in principle; examples include:

[0076] Layered transition metal oxides mainly include LiMO2 (M=Co, Ni, Mn) cathode materials, lithium-rich manganese-based cathode materials, nickel-cobalt-manganese oxide (NCM), and nickel-cobalt-aluminum oxide (NCA) ternary cathode materials.

[0077] Preferably, the positive electrode active material may include Li a Ni x Co y Mn z A b The ternary material of O2; wherein, 0.9≤a≤1.1, 0.5≤x<1, x+y+z=1, 0≤b≤0.1, and A is selected from at least one of Al, Zr, Ti, Mo, W, Zn, Cu, Cr, Mg, Fe, Nb, and B.

[0078] From the perspective of high capacity, ternary layered transition metal oxide cathode materials are preferred because they have higher specific capacity and can better meet the requirements of high energy density.

[0079] Furthermore, for positive electrode active materials, especially for NCM and NCA, the key to improving the discharge capacity of ternary positive electrode materials lies in increasing the proportion of nickel content. Therefore, in a further preferred embodiment of the present invention, the positive electrode active material may include ternary positive electrode materials with medium nickel (mainly 5-series such as NCM523), medium-high nickel (mainly 6-series such as NCM613 and NCM622), and high nickel (mainly 8-series such as NCM811).

[0080] Furthermore, there are no particular limitations on other components in the positive electrode active material layer in principle; for example, they can be binders, conductive agents, and additives commonly used in the art. Such binders can be, for example, fluorinated polyolefins, acrylates, or cellulose binders; suitable conductive agents can be, for example, carbon nanotubes, conductive metal particles, etc.; and suitable additives can be, for example, thickeners, dispersants, etc.

[0081] Similarly, there are no particular limitations on the negative electrode active layer, and compositions commonly used in the art can be used. The negative electrode active layer may include the negative electrode active material, a binder, and optional additives.

[0082] For the negative electrode active material, from the perspective of improving the battery's capacity, it includes the element Si. There are no particular restrictions on the source of such Si element; for example, it can be elemental silicon, silicon oxide, or silicon alloy.

[0083] From the perspective of balancing good capacity and dimensional stability, the negative electrode active material also includes carbon (C). There are no particular restrictions on the source of this C element; it can be, for example, carbon materials or graphite.

[0084] In some preferred embodiments of the present invention, the negative electrode active material includes C and Si elements, that is, the preferred negative electrode active material includes silicon-carbon composite material.

[0085] Furthermore, other components in the negative electrode active material layer, such as binders and other additives, can be selected from conventional components already available in the art.

[0086] Regarding the silicon (Si) content in the negative electrode active material layer, while a higher silicon content results in higher battery energy density, it also leads to significant volume expansion. Therefore, it is necessary to rationally control the silicon content. In some preferred embodiments, the Si content in the negative electrode active material layer is typically 5-30% by mass, more preferably 10-25% by mass, including examples such as 8% by mass, 12% by mass, 14% by mass, 16% by mass, 18% by mass, 20% by mass, 22% by mass, and 28% by mass.

[0087] (Steps for the formation of the active substance layer)

[0088] In the step of forming the active material layer of the present invention, the above-mentioned positive or negative active material layer is formed on the surface of at least one side of the corresponding current collector to form an electrode.

[0089] For the formation of the active material layer, it can usually be used in the form of a slurry. For the formation of the slurry, the various raw materials of the above-mentioned positive or negative electrode active material layer can be mixed at room temperature. If necessary, conventional solvents can be used in the field.

[0090] The active material layer can be formed on the surface of the corresponding current collector (metal foil) using a coating device. The coating amount per unit area is determined according to the design requirements of the positive or negative electrode.

[0091] In some specific implementations, a coated area and an exposed area can be formed on the surface of the current collector. For example, in a direction perpendicular to the processing direction, the edge portion is the exposed area of ​​the current collector. This area can be used for subsequent processes to form tabs.

[0092] There are no particular restrictions on the proportion of the exposed area to the surface area of ​​the current collector electrode. It can be selected according to the specific conditions of the processing equipment, for example, it can be less than 10%.

[0093] (The first pressure processing step)

[0094] The present invention performs a first pressure processing on the above-mentioned active material component, namely the electrode, to perform a first compaction on the active material layer on the surface of the current collector layer.

[0095] Specifically, in the first pressure processing step of the present invention, the component to which the active material layer is formed is subjected to a first pressure processing, thereby imparting a first compaction density η1 to the active material layer.

[0096] There are no particular limitations on the pressure processing apparatus, as long as it can apply continuous tension to the electrode sheet in the processing direction. In some preferred embodiments, the first pressure processing of the present invention can be performed using a pressure roller for roll forming.

[0097] During the first pressure processing, the processing surface of the electrode is compressed, causing the electrode to stretch to a certain extent. At this time, because the area covered with the active material bears greater processing tension than the exposed area, the elongation rate of the covered area is higher than that of the exposed area. To suppress wrinkling of the metal layer in the exposed area or the junction area between the covered and exposed areas that may be caused by this difference in elongation rate between different areas, the tension used in the first pressure processing of this invention is less than the tension required to form the final active material layer.

[0098] Therefore, the first compaction density η1 of the active material layer obtained under the first pressure processing of the present invention is less than the required compaction density specified by the final requirement of the present invention or the finished product, namely the required compaction density η2 as described below.

[0099] The compaction density of this invention can be determined based on the linear density of the layer divided by the thickness of the layer. Furthermore, the following relationship exists between η1 and η2 of this invention:

[0100] η1=(82%~90%)·η2 (1)

[0101] Preferably, the following relationship exists:

[0102] η1=(82%~88%)·η2 (1-a)

[0103] Further examples include η1=82%·η2, η1=84%·η2, η1=86%·η2, η1=90%·η2, etc.

[0104] The absolute value of η1 is related to the case where the positive and negative poles are different, and there is no particular limitation in principle.

[0105] When the electrode component is a positive electrode component, η1' can be 2.0~3.2 g / (m 3 ·10 -6 For example, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1 g / (m 3 ·10 -6 )wait.

[0106] When the electrode component is a negative electrode component, the η1'' can be 1.3~1.5 g / (m 3 ·10 -6), such as 1.4 g / (m 3 ·10 -6 )wait.

[0107] Through the above processing, the thickness of the component (electrode) that forms the active material layer is given as d1. There is no particular limitation on the absolute value of d1, which is related to the thickness of the current collector used and the tension of the first processing.

[0108] Furthermore, there are no particular restrictions on the temperature conditions for the first pressure processing, which can generally be carried out at room temperature. In some specific embodiments, when the first pressure processing is performed using pressure rollers, the preferred roller pressure is 50~80T, the roller speed is 3~8m / min, the tension is 50~200 N, and the roller gap can be controlled at 120~200μm.

[0109] Through the above processing, especially the first compaction of the active material layer by the first pressure processing, it is possible to ensure that a suitable tension is applied to the electrode component. Under this tension, not only can the active material layer (slurry layer) obtain good distribution and surface smoothness, but the current collectors in the covered area and the exposed area can also reduce the occurrence of wrinkles caused by the difference in elongation.

[0110] (Steps for introducing the solid electrolyte layer)

[0111] The introduction of the solid electrolyte in this invention refers to the step of forming a solid electrolyte layer on a surface on which an active material layer (having a first compaction density η1) has been formed.

[0112] Solid electrolytes can typically be oxide solid electrolytes or hybrid solid electrolytes that combine oxide solid electrolytes and polymer solid electrolytes.

[0113] For oxide solid electrolytes, there are no particular restrictions in principle; examples include perovskite type (such as Li₂). 3x La2 / 3- x TiO3, LLTO), garnet type (such as Li7La3Zr2O) 12 LLZO), NASICON type (such as Li 1.3 Al 0.3 Ti 1.7 (PO4)3, LATP, etc.

[0114] There are no particular restrictions on polymer solid electrolytes in principle. Examples include polyethylene oxide (PEO) based electrolytes, polyacrylonitrile (PAN) based electrolytes, and polyvinylidene fluoride (PVDF) based electrolytes.

[0115] For hybrid electrolytes formed by oxide solid electrolytes and polymer solid electrolytes, the two can be combined into a hybrid system according to the requirements of compatibility, flexibility, etc. Examples include PEO and LLZO hybrid electrolytes and polymer-ceramic composite electrolytes.

[0116] For the introduction of solid electrolytes, a solid electrolyte layer can be formed on the surface of the active material layer of the electrode by means of extrusion, or a film or sheet can be formed by pre-processing the solid electrolyte and then covering the surface of the active material layer.

[0117] There are no special requirements for the thickness d2 of the formed solid electrolyte layer, which is related to the final thickness d4 of the solid electrolyte layer obtained after the subsequent second compaction process. In some specific embodiments, d2 can be 5 to 70 μm, preferably 6 to 60 μm, and also includes 10, 15, 20, 25, 30, 35, 40, 45, 50, and 55 μm.

[0118] (The second pressure processing step)

[0119] In the second pressure processing of the present invention, the electrode component with the solid electrolyte layer is further compacted so that the active material layer (slurry layer) and the solid electrolyte layer form the final compaction density.

[0120] There are no particular limitations on the pressure processing apparatus, as long as it can apply continuous tension to the electrode components in the processing direction. In some preferred embodiments, the second pressure processing of the present invention can be performed using a pressure roller for roll forming.

[0121] The second compaction density η2 of the active material layer obtained under the second pressure processing of the present invention is greater than the first compaction density η1 mentioned above, and the second compaction density is the required compaction density of the active material layer or the value when the electrode components are assembled into the battery.

[0122] Furthermore, through a second pressure processing, the thickness of the electrode (the sum of the current collector layer and the active material layer) can be changed from d1 in the first pressure processing to d3. In some preferred embodiments, d1 and d3 satisfy the following relationship:

[0123] d1=1.14~1.18d3 (2)

[0124] Other examples include d1=1.15d3, d1=1.16d3, d1=1.17d3, etc.

[0125] Furthermore, the absolute value of η2 is related to the case where the positive and negative poles are different, and there are no special restrictions in principle.

[0126] When the electrode component is a positive electrode component, η2' can be 2.3~3.6 g / (m 3 ·10 -6 For example, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5 g / (m 3 ·10 -6 ), etc. Preferably, when the positive electrode active material is a ternary lithium active material, η2' can be 3.4~3.6 g / (m). 3 ·10 -6 When the positive electrode active material is lithium iron phosphate, η2' can be 2.3~2.8 g / (m 3 ·10 -6 ).

[0127] When the electrode component is a negative electrode component, the η2'' can be 1.6~1.8 g / (m 3 ·10 -6 For example, 1.7 g / (m 3 ·10 -6 )wait.

[0128] Furthermore, after the second pressure processing, the thickness d4 of the solid electrolyte layer is typically between 0.4 and 0.6 times that of d2. The final compaction density η3 of the solid electrolyte layer is typically between 0.82 and 1.60 g / (m³). 3 ·10 -6 ).

[0129] Furthermore, there are no particular restrictions on the temperature conditions for the second pressure processing, and it can generally be carried out at room temperature. In some specific embodiments, when using pressure rollers, the preferred roller pressure is 50~80T, the roller speed is 3~8m / min, and the tension is 50~200 N. In addition, the roller gap can be controlled at 120~200μm. Moreover, the tension of the second pressure processing is higher than that of the first pressure processing.

[0130] Through the above processing, the final electrode component of the present invention is obtained.

[0131] The above processing method describes the formation of an active material layer and a solid electrolyte layer on one side of the current collector. For the case where the above-described stack is formed on both sides, at least one side or both sides satisfy the above description.

[0132] [Electrodes and Batteries]

[0133] The second part of the present invention provides an electrode comprising an electrode component obtained based on the method of the first aspect described above.

[0134] In addition to the electrode components described above, the electrode of the present invention also includes a tab.

[0135] In some preferred embodiments, the electrode tab may be formed from the exposed portion of the current collector in the above processing method, that is, it is integrally formed with the electrode component of the present invention.

[0136] With such a design, multi-pole or all-pole electrodes can be obtained.

[0137] Furthermore, the battery of the present invention can be a battery including the electrodes described above. Such electrodes can be positive or negative electrodes. Therefore, the battery of the present invention can include corresponding electrodes, and optionally may include or exclude a separator, liquid electrolyte, etc.

[0138] Furthermore, the battery of the present invention is a quasi-solid-state battery or an all-solid-state battery.

[0139] Such batteries can be either power batteries or batteries for energy storage systems. Power batteries can be used in ground or air transportation vehicles for goods and passengers. Batteries for energy storage systems can be used in energy storage devices within wind power, hydropower, tidal power, and solar power systems.

[0140] Example

[0141] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0142] It should be noted that the "solid layer" in the following embodiments is formed using the same type of oxide solid electrolyte.

[0143] Example 1

[0144] The electrode components are manufactured using the following steps:

[0145] S1: The positive electrode is prepared by wet homogenization, in which ternary positive electrode material, conductive agent, carbon nanotubes and binder are prepared in a mass ratio of 97:1:0.5:1.5.

[0146] Meanwhile, the negative electrode is prepared by mixing graphite with silicon, conductive agent, thickener and binder in a ratio of 96:1:1:2.

[0147] S2: The prepared positive electrode slurry is coated onto the surface of the positive electrode aluminum foil, and the negative electrode slurry is coated onto the negative electrode copper foil;

[0148] S3: Positive electrode roller pressing, roller pressing until the slurry layer compaction density is 2.92 g / (m³) 3 ·10 -6 The resulting electrode sheet had a thickness of 106 μm and was compacted to 84.6% of the final required compaction. The negative electrode was then rolled normally to the required compaction of 1.6 g / (m²). 3 ·10 -6 ).

[0149] S4: Solid layer is introduced into the positive electrode (solid layer is lithium rhenium zirconium oxide: thickener: binder = 8:1:1), and the thickness of the solid layer is 7um on one side; the negative electrode does not conduct solid layer.

[0150] S5: The compaction density of the slurry layer after secondary roller pressing of the positive electrode is 3.45 g / (m³). 3 ·10 -6 ), corresponding to a 97um electrode thickness, and a solid layer thickness of 3.5±0.5um on one side;

[0151] Example 2

[0152] The electrode components are manufactured using the following steps:

[0153] S1: The ternary cathode material, conductive agent, carbon nanotubes and binder are prepared by wet homogenization at a mass ratio of 97:1:0.5:1.5; the anode material is prepared by silicon-doped graphite, conductive agent, thickener and binder at a mass ratio of 96:1:1:2.

[0154] S2: The prepared positive electrode slurry is coated onto the surface of the positive electrode aluminum foil, and the negative electrode slurry is coated onto the negative electrode copper foil;

[0155] S3: The positive electrode roller needs to be compacted to 3.45 g / (m²) of the slurry layer. 3 ·10 -6 );

[0156] The compaction density of the slurry layer after the negative electrode roller is pressed is 1.32 g / (m³). 3 ·10 -6 The corresponding electrode thickness is 90µm;

[0157] S4: Solid-state layer is introduced into the negative electrode, and the thickness of the solid-state layer is 12um on one side.

[0158] S5: The secondary roller of the negative electrode needs to be pressed to a compaction density of 1.6 g / (m³) into the slurry layer. 3 ·10 -6 ), corresponding to a 97um electrode thickness, of which the solid layer thickness is 5±0.5um on one side.

[0159] Example 3

[0160] The electrode components are manufactured using the following steps:

[0161] S1: The LFP positive electrode material, conductive agent, carbon nanotubes and binder are slurried in a mass ratio of 96.5:1:0.5:2 using a wet homogenization method; the negative electrode is slurried in a mass ratio of 96:1.5:1:1.5 using graphite, conductive agent, thickener and binder.

[0162] S2: The prepared slurry is coated with positive and negative electrodes;

[0163] S3: The positive electrode roller is pressed to a compaction level of 2.3 g / (m²). 3 ·10 -6 ), corresponding to a thickness of 91um;

[0164] The negative electrode roller is pressed to the required compaction density of 1.6 g / (m³). 3 ·10 -6 );

[0165] S4: Solid-state layer is introduced into the positive electrode, and the thickness of the solid-state layer is 14um on one side.

[0166] S5: The positive electrode secondary roller is pressed to the required compaction, with a compaction density of 2.6 g / (m³). 3 ·10 -6 ( ), corresponding to a 97um electrode thickness, the secondary roll forming mainly rolls the solid layer, where the single-sided thickness of the solid layer is 7±0.5um.

[0167] Comparative Example 1

[0168] The electrode components are manufactured using the following steps:

[0169] S1: Prepare the positive electrode slurry, negative electrode slurry, current collector, and solid electrolyte in the same manner as in Example 1;

[0170] S2: The prepared slurry is then coated.

[0171] S3: The positive electrode is directly rolled to the required compaction density of 3.45 g / (m³). 3 ·10 -6 The negative electrode is directly rolled to the required compaction density of 1.6 g / (m³). 3 ·10 -6 );

[0172] S4: The positive electrode is introduced into a solid layer and rolled, with the thickness being the same as the final solid layer thickness in Example 1.

[0173] Comparative Example 2

[0174] S1: Prepare the positive electrode slurry, negative electrode slurry, current collector, and solid electrolyte in the same manner as in Example 2;

[0175] S2: The prepared slurry is then coated.

[0176] S3: The positive electrode is directly rolled to the required compaction density of 3.45 g / (m³). 3 ·10 -6 The negative electrode is directly rolled to the required compaction density of 1.6 g / (m³). 3 ·10 -6 );

[0177] S4: The negative electrode is introduced into a solid layer and rolled, with the thickness being the same as the final solid layer thickness in Example 2.

[0178] Morphological characteristics :

[0179] See appendix Figure 2-6 It shows the morphology of the electrode sheets containing solid layers obtained in the embodiments and comparative examples, wherein:

[0180] Figures 2-4 The results show that the tab wrinkles are suppressed during processing, with only slight wrinkles visible. The material area has no black and white curve intersections and maintains a smooth and uniform surface.

[0181] Figure 5 The data shows obvious stress marks in the material area after the active layer is compacted by roller pressing. In particular, the electrode tab area of ​​the electrode sheet is severely wrinkled after the final roller pressing after the solid layer is introduced. Therefore, abnormal problems such as strip breakage, electrode tab cracking, and obvious wrinkles are prone to occur during processing.

[0182] Figure 6 The results show that after the active layer is rolled and compacted, the tabs show obvious wrinkles and fishtail patterns. In particular, after the solid layer is introduced and rolled, the tabs show obvious wrinkles. At the same time, black and white boundaries appear in the material area, indicating that the surface of the material area is unevenly distributed.

[0183] Because the solid-layer electrode shown in the examples has a good shape, its product yield in electrode component production is significantly higher than that of Comparative Example 1 and Comparative Example 2.

[0184] It should be noted that although the technical solution of the present invention has been described with specific examples, those skilled in the art will understand that the present invention should not be limited thereto.

[0185] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for preparing an electrode component, characterized in that, The electrode component includes a current collector layer, an active material layer on at least one side of the current collector layer, and a solid electrolyte layer. The method includes: The steps include the formation of the active material layer, the first pressure processing step, the introduction of the solid electrolyte layer, and the second pressure processing step. in, In the step of forming the active material layer, the active material layer is formed on at least one side of the current collector layer. In the first pressure processing step, the component with the active material layer is subjected to the first pressure processing, thereby giving the active material layer a first compaction density η1; In the step of introducing the solid electrolyte layer, the solid electrolyte layer is formed on the surface of the active material layer of the component obtained by the first pressure processing; In the second pressure processing step, the component with the introduced solid electrolyte layer is subjected to a second pressure processing, thereby imparting a second compaction density η2 to the active material layer. Furthermore, the first compaction density η1 and the second compaction density η2 satisfy the following relationship: η1=(82%~90%)·η2 (1) Where η2 is the value of the electrode components directly assembled into the battery.

2. The method according to claim 1, characterized in that, In the first pressure processing step, the total thickness of the current collector layer and the active material layer is d1; in the second pressure processing step, the total thickness of the current collector layer and the active material layer is d3. Wherein, d1 and d3 satisfy the following relationship: d1=1.14~1.18d3 (2).

3. The method according to claim 1 or 2, characterized in that, The current collector is a metal foil.

4. The method according to claim 1 or 2, characterized in that, In the step of forming the active material layer, the active material layer is formed in the form of a slurry coating.

5. The method according to claim 1 or 2, characterized in that, In the step of introducing the solid electrolyte layer, the thickness d2 of the solid electrolyte layer formed on the surface of the active material layer is 5~70μm.

6. The method according to claim 1 or 2, characterized in that, In the second pressure processing step, the second pressure processing imparts a compaction density η3 of 0.82~1.60 g / (m³) to the solid electrolyte layer. 3 ·10 -6 ).

7. The method according to claim 1 or 2, characterized in that, Both the first and second pressure processing are performed using pressure rollers, with the pressure rollers applying a tension of 50~200N. Furthermore, the tension applied by the pressure rollers in the first pressure processing is lower than the tension applied by the pressure rollers in the second pressure processing.

8. The method according to claim 1 or 2, characterized in that, The η2 includes the following cases: when the electrode component is a positive electrode component, the η2' is 2.3~3.6 g / (m 3 ·10 -6 When the electrode component is a negative electrode component, the η2'' is 1.6~1.8 g / (m). 3 ·10 -6 ).

9. The method according to claim 1 or 2, characterized in that, The solid electrolyte layer includes oxide solid electrolytes, polymer solid electrolytes, or a mixture of solid electrolytes in any proportion thereof.

10. A battery electrode comprising an electrode component obtained by the preparation method according to any one of claims 1 to 9.

11. A lithium secondary battery, characterized in that, It includes or uses the electrode component as described in claim 10.

12. The lithium secondary battery according to claim 11, characterized in that, It is a battery or power battery used in energy storage systems.

Images