Electrode plates for lithium secondary batteries and lithium secondary batteries containing the same

Abstract

The present invention relates to an electrode plate for a lithium secondary battery and a lithium secondary battery including the same, comprising a current collector layer and an electrode mixture layer formed on one or both sides of the current collector layer, wherein the electrode mixture layer comprises a first region formed in the direction of the other edge portion with respect to the transverse (TD) cross-section of the electrode mixture layer from one edge portion of the electrode mixture layer, and a second region excluding the first region, wherein the electrode mixture layer comprises first particles and second particles each comprising an electrode active material, a conductive material, and a binder, wherein the first particles have a higher binder content than the second particles, or the region containing 30% or more of the total binder content contained in the particle is 20% or less of the length from the outermost surface portion of the particle to the center of the particle.

Description

[Technical Field]

[0001] This application claims priority rights under Korean Patent Application No. 10-2023-0040898 dated March 29, 2023, and Korean Patent Application No. 10-2024-0042597 dated March 28, 2024, and incorporates all the contents disclosed in the documents of said Korean Patent Applications as part of this Specification.

[0002] This invention relates to an electrode plate for a lithium secondary battery and a lithium secondary battery containing the same. [Background technology]

[0003] Recent key trends in the development of the electronics industry can be summarized as the shift towards wireless and mobile devices, and the transition from analog to digital. The rapid proliferation of mobile devices and laptops, and the shift from analog to digital cameras, are prime examples of this trend.

[0004] In addition to these trends, research and development of secondary batteries as power sources for devices are actively underway. Among these, lithium secondary batteries, which use lithium transition metal oxides or lithium composite oxides as the positive electrode active material and offer high power-to-capacity ratios, are attracting considerable attention. A lithium secondary battery consists of an electrode assembly of a positive electrode, a separator membrane, and a negative electrode, which is housed in a sealed container along with an electrolyte.

[0005] On the other hand, electrodes generate electric current through ion exchange, and the positive and negative electrodes that make up the electrodes are constructed by coating an electrode active material onto an electrode current collector made of metal.

[0006] Generally, the positive electrode consists of an electrode plate made of aluminum or the like coated with an active material such as LiCoO2, LiMnO2, or LiNiO2, while the negative electrode consists of an electrode plate made of copper or aluminum or the like coated with a carbon-based active material.

[0007] In order to manufacture electrode plates such as positive or negative electrodes, an electrode current collector, which is made of a metal sheet that is long in one direction, is coated with an electrode mixture containing an electrode active material at regular intervals, and then processed into a set electrode shape.

[0008] The methods for applying electrode material to electrode plates can be broadly divided into wet electrode processes and dry electrode processes.

[0009] The wet electrode process is characterized by a process in which, in the process of preparing the electrode mixture to be applied to the current collector, the main components contained in the electrode mixture, such as the electrode active material, conductive material, and binder, are mixed using an organic solvent such as N-methyl-2-pyrrolidone (NMP) to produce an electrode mixture slurry, and this slurry is then applied to the electrode current collector.

[0010] The aforementioned wet electrode process must inevitably go through a step in which organic solvents such as NMP, which were separately added to produce the electrode mixture slurry, must be removed in order to ultimately manufacture the electrode. However, in this process, some of the binder dissolved in the organic solvent may fall off, which can reduce the bonding force between the electrode active material / conductive material and the current collector. Furthermore, the drying process to remove the organic solvent consumes a large amount of electricity and costs.

[0011] To overcome the shortcomings of such wet electrode processes, a dry electrode process has emerged in recent years, in which the electrode mixture is directly applied to the current collector without adding a separate organic solvent during the manufacturing process. When manufacturing electrodes for lithium secondary batteries using this dry electrode process, it is environmentally friendly because no separate solvent is used in the preparation of the electrode mixture, and it simplifies the process and reduces costs because there is no need for a separate solvent drying step. Furthermore, since the electrode mixture can be applied to the current collector through the rolling process, the thickness of the electrode can be reduced, and the energy density of the electrode can be improved, making it a suitable method for manufacturing high-nickel or all-solid-state batteries.

[0012] However, in the dry electrode process, since the step of preparing the electrode mixture slurry using a separate organic solvent during electrode mixture manufacturing is not performed, the electrode mixture coating on the electrode edge becomes relatively weaker compared to the wet electrode process, and there is a problem that the electrode mixture may detach at the edge, and a solution to this problem is urgently needed. [Prior art documents] [Patent Documents]

[0013] [Patent Document 1] Japanese Patent Publication No. 2022-075282 (May 18, 2022) [Overview of the project] [Problems that the invention aims to solve]

[0014] The object of the present invention is to provide an electrode plate for a lithium secondary battery that includes an electrode mixture layer, and by arranging particles with a high binder content or a high surface binder content in a specific region formed from the edge of the mixture layer, it is possible to prevent the electrode plate edge from separating and increase the energy density of the electrode plate, even when the electrode plate is manufactured using a dry electrode process.

[0015] Another object of the present invention is to provide a lithium secondary battery including the aforementioned lithium secondary battery electrode plates. [Means for solving the problem]

[0016] One embodiment of the present invention provides an electrode plate for a lithium secondary battery, comprising a current collector layer and an electrode mixture layer formed on either one or both sides of the current collector layer, wherein the electrode mixture layer comprises a first region formed in the direction of the other edge portion with respect to the transverse (TD) cross-section of the electrode mixture layer from one edge portion of the electrode mixture layer, and a second region excluding the first region, wherein the electrode mixture layer comprises first particles and second particles each comprising an electrode active material, a conductive material, and a binder, wherein the first particles have a higher binder content than the second particles, or the region containing 30% or more of the total binder content contained within the particle is 20% or less of the length from the outermost surface portion of the particle to the center of the particle.

[0017] The first particle may be located in the first region, and the second particle may be located in the second region.

[0018] The first and second particles may be in granular form.

[0019] The average particle size of the first and second particles may be 30 to 100 μm, respectively.

[0020] The first region may be formed with an area ratio of 1% to 20% based on the total area of ​​the electrode mixture layer.

[0021] The binder content ratio of the first particle to the binder content ratio of the second particle may be between 1.2:1 and 3.0:1.

[0022] The binder contained in the first and second particles may be at least one of the following: polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyethylene (PE), high molecular weight polyethylene (HMWPE), ultra-high molecular weight polyethylene (UHMWPE), polypropylene (PP), carboxymethylcellulose (CMC), polyvinylphenol, polyvinylpyrrolidine, polyvinyl acetate, polyvinyl alcohol, and polyacetylene.

[0023] The first particles may contain 3.6 to 9% by weight of a binder based on the total weight of the first particles, and the second particles may contain 1 to 5% by weight of a binder based on the total weight of the second particles.

[0024] The first particles and the second particles can each independently further contain a sulfide-based solid electrolyte represented by the following Chemical Formula 1.

[0025] [Chemical Formula 1] Li k M 2 l S m X 2 n

[0026] In Chemical Formula 1, M 2 is Sn, Mg, Ba, B, Al, Ga, In, Si, Ge, Pb, N, P, As, Sb, Bi, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Hf, Ta, W, or La, and X 2 is F, Cl, Br, I, Se, Te, or O, 0 < k ≤ 6, 0 < l ≤ 6, 0 < m ≤ 6, and 0 ≤ n ≤ 6.

[0027] One embodiment of the present invention provides a lithium secondary battery including the electrode plate for a lithium secondary battery.

Advantages of the Invention

[0028] According to the present invention, by arranging particles with a high binder content or a high surface layer binder content in a specific region formed from the edge portion of the binder layer while the electrode plate for a lithium secondary battery includes an electrode binder layer, even when manufacturing the electrode plate in a dry electrode process, it is possible to prevent detachment of the edge portion of the electrode plate and increase the energy density of the electrode plate. Further, when manufacturing the electrode plate for a lithium secondary battery, by not applying a wet electrode process, the drying stage of the organic solvent in the electrode binder slurry can be omitted, so it is an environmentally friendly process and the production cost can be reduced, making it economical. [Brief explanation of the drawing]

[0029] [Figure 1] This is a schematic diagram showing the structure of an electrode plate for a lithium secondary battery according to one embodiment of the present invention. [Figure 2] This is a schematic diagram showing the structure of an electrode plate for a lithium secondary battery according to one embodiment of the present invention. [Figure 3] This figure shows an image of an electrode mixture layer containing particles formed on a current collector according to a manufacturing example and a comparative manufacturing example of the present invention. [Figure 4] and [Figure 5] This figure shows scanning electron microscope (SEM) images of particles produced according to an example of the present invention, and the results of measuring the average particle size using a particle size analyzer. [Figure 6] This figure shows an image of an electrode plate for a lithium secondary battery according to one embodiment of the present invention. [Figure 7] This figure shows an image of an electrode plate for a lithium secondary battery according to one embodiment of the present invention. [Figure 8] This figure shows an image of an electrode plate for a lithium secondary battery according to one embodiment of the present invention. [Figure 9] This figure shows a scanning electron microscope (SEM) image of an electrode plate for a lithium secondary battery according to one embodiment of the present invention. [Figure 10] This figure shows a carbon EDS mapping image of an electrode plate for a lithium secondary battery according to one embodiment of the present invention. [Modes for carrying out the invention]

[0030] Embodiments of the present invention will now be described in detail. Prior to this, terms and words used in this specification and in the claims should not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather in a manner consistent with the technical idea of ​​the present invention, based on the principle that inventors may appropriately define the concepts of terms in order to best describe their invention. Therefore, it should be understood that the configurations described in the embodiments described herein represent only one of the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that at the time of filing, there may be various equivalents and modifications that can substitute for them.

[0031] In the entirety of this specification, when a part "includes" a certain component, unless otherwise stated, this does not mean that other components are excluded, but rather that other components may be included.

[0032] Furthermore, explanations that specify or add components can be applied to all inventions unless otherwise restricted, and are not limited to specific inventions.

[0033] Furthermore, throughout the description of the invention and the claims of this application, singular nouns include plural nouns unless otherwise specified.

[0034] Furthermore, throughout the description of the invention and the claims of this application, "or" includes "and" unless otherwise specified. Therefore, "including A or B" means all three cases: including A, including B, or including both A and B.

[0035] Furthermore, all numerical ranges include the values ​​at both ends and all intermediate values ​​between them, unless otherwise explicitly stated.

[0036] Throughout this specification, the average particle size may be, for example, the median diameter (D50) measured using a laser particle size analyzer.

[0037] The following describes a composite sulfide-based solid electrolyte according to one embodiment of the present invention.

[0038] The present invention relates to an electrode plate for a lithium secondary battery and a lithium secondary battery containing the same, which can prevent the detachment of the electrode plate edge and improve the energy density of the electrode plate when manufacturing electrodes for lithium secondary batteries in a dry electrode process.

[0039] Figure 1 is a schematic diagram showing an electrode plate for a lithium secondary battery according to one embodiment of the present invention. Referring to Figure 1, the electrode plate (100) for a lithium secondary battery according to one embodiment of the present invention includes a current collector layer (not shown) and an electrode mixture layer formed on either one or both sides of the current collector layer. The electrode mixture layer includes a first region (10) formed from one edge portion (50) of the electrode mixture layer toward the other edge portion with respect to the transverse (TD) cross-section of the electrode mixture layer, and a second region (20) excluding the first region. The electrode mixture layer includes first particles (30) and second particles (40), each containing an electrode active material, a conductive material, and a binder, respectively. The first particle (30) has a higher binder content than the second particle (40), or contains 30% or more of the total binder content in the particle in a region that is 20% or less of the length from the outermost surface of the particle to the center of the particle.

[0040] The electrode plate for lithium secondary batteries according to the present invention contains particles with a specific structure in which the binder content is high in a region formed within a certain range based on the edge portion of the electrode mixture layer and the transverse (TD) cross-section of the electrode mixture layer, or in which the binder content is unevenly distributed in a specific region along the length from the outermost surface of the particle to the center of the particle. This allows for the manufacture of the electrode plate for lithium secondary batteries, particularly when the electrode plate is manufactured through a so-called "dry electrode process" that does not use a separate solvent such as an organic solvent to manufacture the electrode mixture, by providing improved bonding strength at the edge portion of the electrode plate, thereby preventing detachment of the edge portion. Furthermore, because the lithium secondary battery electrode plate can be easily applied through the dry electrode process, the energy density of the electrode plate can also be improved compared to an electrode plate manufactured in a wet electrode process.

[0041] In the present invention, the electrode plate for a lithium secondary battery can mean a structure in which an electrode current collector, which includes a metal sheet formed to be elongated in one direction, is coated with an electrode mixture containing an electrode active material.

[0042] In the present invention, the electrode mixture can mean a mixture applied to an electrode plate for a lithium secondary battery, and may be a composition of, for example, an electrode active material, a conductive material, a binder, and other components, each of which will be described later.

[0043] In one embodiment of the present invention, the first particles (30) and the second particles (40) may be granules formed by mixing and agglomerating constituent particles of the electrode active material, conductive material, binder, and other components contained in each particle. For example, the first particles (30) and the second particles (40) may be granules in which constituent particles of the electrode active material, conductive material, binder, and other components are uniformly mixed and distributed, or they may have a granule form in which any of the constituent components are biased to a particular region.

[0044] In one embodiment of the present invention, the average particle size of the first particle (30) may be 30 to 100 μm, for example, 35 to 95 μm, 40 to 90 μm, and preferably 50 to 80 μm.

[0045] In one embodiment of the present invention, the average particle size of the second particle (40) may be 30 to 100 μm, for example, 35 to 95 μm, 40 to 90 μm, and preferably 50 to 80 μm.

[0046] In one embodiment of the present invention, the first particle (30) may contain 3.6 to 9% by weight of binder relative to the total weight of the first particle, which includes the electrode active material, conductive material, and binder. For example, it may contain 3.6 to 8.0% by weight, 3.8 to 7.0% by weight, preferably 4.0 to 6.0% by weight of binder.

[0047] If the binder content of the first particles is less than 3.6% by weight, there is a problem that the adhesion strength of the primary particles applied to the edges of the lithium secondary battery electrode plates may decrease. If it exceeds 9% by weight, there is a problem that the resistance of the electrode plates may increase due to the first particles. Therefore, it should be appropriately adjusted within the above range.

[0048] In one embodiment of the present invention, the second particle (40) may contain 1 to 5% by weight of binder relative to the total weight of the second particle, which includes the electrode active material, conductive material, and binder. For example, it may contain 1.5 to 4.5% by weight, 2 to 4.0% by weight, and preferably 2.5 to 3.5% by weight of binder.

[0049] If the binder content of the second particle is less than 1% by weight, there is a problem that the manufacturing yield of the second particle may decrease, and if it exceeds 5% by weight, there is a problem that the resistance of the electrode plate may increase due to the second particle; therefore, it should be appropriately adjusted within the above range.

[0050] Furthermore, in one embodiment of the present invention, the binder content ratio of the first particle (30) to the binder content ratio of the second particle (40) may be 1.2:1 to 3.0:1, for example, 1.3:1 to 2.9:1, 1.4:1 to 2.8:1, or 1.5:1 to 2.7:1.

[0051] If the binder content ratio of the second particle to the binder content ratio of the first particle is less than the range described above, there is a problem that the adhesive strength improvement effect of the first and second particles on the electrode plate for lithium secondary batteries may decrease. If it exceeds the range described above, there is a problem that the resistance of the electrode plate may increase. Therefore, in order to prevent the detachment of the electrode plate edge portion that may occur when manufacturing the electrode plate for lithium secondary batteries according to the present invention using a dry electrode process, it is preferable that the binder content in the first particle (30) and the second particle (40) contained in the electrode mixture layer satisfies the range described above.

[0052] In the case of the first particle (30) contained in the electrode mixture layer of the electrode plate for a lithium secondary battery according to the present invention, it may have a higher binder content within the particle compared to the second particle (40), or it may be distributed in a form in which 30% or more of the binder content contained within the particle is contained in a region that is 20% or less of the length from the outermost surface of the particle to the center of the particle.

[0053] For example, the first particle (30) may have a "core-shell structure" in which a shell portion of the first particle (30) is formed in a region that is 20% of the length from the outermost surface of the particle to the center of the particle, and the remaining region up to the center is formed as a "core". In this case, the shell portion of the first particle (30) may contain 30% or more of the binder content contained in the first particle. That is, the first particle (30) contains an electrode active material, a conductive material, and a binder, and in particular has the characteristic that the binder is distributed such that it is biased towards the relative outer part of the first particle, thereby increasing the bonding force with other adjacent first particles or current collector layers, and playing a role in preventing the detachment of the edge portion of the electrode plate for lithium secondary batteries.

[0054] When the first particle (30) is formed as a "core-shell structure" as described above, the region in which the binder is unevenly distributed may be a region that is 20% of the length from the outermost surface of the particle to the center of the particle, or a region that is 1% to 20% of the length from the outermost surface of the particle to the center of the particle.

[0055] When the first particle (30) is formed as a "core-shell structure" as described above, the region that is 20% or less of the length from the outermost surface of the particle to the center of the particle can contain 30% or more of the binder of the total binder content contained within the first particle.

[0056] In one embodiment of the present invention, the binder contained in the first particle (30) and the second particle (40) may be at least one of the following: polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyethylene (PE), high molecular weight polyethylene (HMWPE), ultra-high molecular weight polyethylene (UHMWPE), polypropylene (PP), carboxymethylcellulose (CMC), polyvinylphenol, polyvinylpyrrolidine, polyvinyl acetate, polyvinyl alcohol, and polyacetylene, and preferably polytetrafluoroethylene (PTFE) may be used.

[0057] In one embodiment of the present invention, the first particles (30) may be included in the first region (10) of the electrode mixture layer, and the second particles (40) may be included in the second region (20) of the electrode mixture layer.

[0058] The first region (10) refers to a portion formed in a fixed area from one edge portion (50) of the electrode mixture layer toward the other edge portion, with reference to the transverse (TD) cross-section of the electrode mixture layer. It can be formed on either one or both edges of the electrode mixture layer, and preferably on both edges of the positive electrode in order to prevent detachment of the edges of the electrode plate for the lithium secondary battery.

[0059] Referring to Figure 2, in the lithium secondary battery electrode plate (200) according to the present invention, the first region may be formed on both the first edge portion (60) and the second edge portion (70) of the electrode mixture layer as needed, and may be formed as first regions (11, 13) having different areas from each other.

[0060] In one embodiment of the present invention, the first region (10, 11, 13) can be formed with an area ratio of 1% to 20% of the total area of ​​the electrode mixture layer, for example, with an area ratio of 2% to 19%, 3% to 18%, and preferably 5% to 15%.

[0061] If the area ratio of the first region is less than 1% of the total area of ​​the electrode mixture layer, there is a possibility that the adhesive strength of the electrode plate edge for lithium secondary batteries may decrease. If it exceeds 20%, there is a possibility that the resistance of the electrode plate may increase. Therefore, it should be appropriately adjusted within the above range.

[0062] Another embodiment of the present invention provides a lithium secondary battery including the electrode plate for the lithium secondary battery.

[0063] The lithium secondary battery may be a battery in which a positive electrode, a negative electrode, and a separator membrane interposed between the positive and negative electrodes are included, or it may be an all-solid-state battery in which a solid electrolyte is included between the positive and negative electrodes without using a separate separator membrane.

[0064] The electrode plate for the lithium secondary battery according to the present invention may be either a positive electrode or a negative electrode.

[0065] The positive electrode may have a structure in which a positive electrode mixture layer is laminated on one or both sides of the positive electrode current collector.

[0066] For example, the positive electrode mixture layer may include a positive electrode active material, a conductive material, and a binder, and may further include positive electrode additives commonly used in the industry, as needed.

[0067] The positive electrode active material is not particularly limited in type, as long as it is a material capable of reversible intercalation and release of lithium ions. For example, it may contain one or more composite compounds of metals such as cobalt, manganese, nickel, iron, or combinations thereof, and lithium.

[0068] As a more specific example, as the positive electrode active material, a compound represented by any one of the following chemical formulas can be used. Li a A 1-b R b D2 (in the above formula, 0.90 ≤ a ≤ 1.8 and 0 ≤ b ≤ 0.5); Li a E 1-b R b O 2-c D c (in the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5 and 0 ≤ c ≤ 0.05); LiE 2-b R b O 4-c D c (in the above formula, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); Li a Ni 1-b-c Co b R c D α (in the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05 and 0 < α ≤ 2); Li a Ni 1-b-c Co b R c O 2-α Z α (in the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05 and 0 < α < 2); Li a Ni 1-b-c Co b R c O 2-α Z2 (in the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05 and 0 < α < 2); Li a Ni 1-b-c Mn b R c D α (in the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05 and 0 < α ≤ 2); Li a Ni 1-b-c Mn b R c O 2-α Zα (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05 and 0 < α < 2); Li a Ni 1-b-c Mn b R c O 2-α Z2 (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05 and 0 < α < 2); Li a Ni b E c G d O2 (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, and 0.001 ≤ d ≤ 0.1); Li a Ni b Co c Mn d G e O2 (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.5, and 0 ≤ e ≤ 0.1); Li a NiG b O2 (In the above formula, 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); Li a CoG b O2 (In the above formula, 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); Li a MnG b O2 (In the above formula, 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); Li a Mn2G b O4 (In the above formula, 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); QO2; QS2; LiQS2; V2O5; LiV2O5; LiTO2; LiNiVO4; Li (3-f) J2(PO4)3(0 ≤ f ≤ 2);Li (3-f) Fe2(PO4)3 (0 ≤ f ≤ 2); and LiFePO4.

[0069] In the above chemical formula, A is Ni, Co, Mn or a combination thereof; R is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements or a combination thereof; D is O, F, S, P or a combination thereof; E is Co, Mn or a combination thereof; Z is F, S, P or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V or a combination thereof; Q is Ti, Mo, Mn or a combination thereof; T is Cr, V, Fe, Sc, Y or a combination thereof; J is V, Cr, Mn, Co, Ni, Cu or a combination thereof.

[0070] The conductive material is not particularly limited as long as it does not induce a chemical change in the battery and is conductive. For example, graphite such as natural graphite or artificial graphite; carbon black such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black; conductive fibers such as carbon fibers and metal fibers; metal powders such as carbon fluoride, aluminum, and nickel powder; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives can be used. The conductive material may be included in an amount of about 0.01 to 10 parts by weight, or 0.01 to 5 parts by weight, or 0.01 to 3 parts by weight, based on 100 parts by weight of the entire positive electrode mixture layer.

[0071] The aforementioned binder is an added component that takes into consideration the binding properties of the positive electrode active material, conductive material, and other components of the positive electrode mixture layer. As the binder included in the electrode mixture layer according to the present invention is as described above, no further explanation will be provided below.

[0072] If the lithium secondary battery according to the present invention is an all-solid-state battery that includes a solid electrolyte layer between the positive electrode and the negative electrode, the positive electrode may further contain a solid electrolyte.

[0073] The solid electrolyte can be broadly classified into a polymer solid electrolyte, an oxide solid electrolyte, or a sulfide solid electrolyte. For example, when the sulfide solid electrolyte is included in the positive electrode, the sulfide solid electrolyte can be represented by the following Chemical Formula 1.

[0074] [Chemical Formula 1] Li k M 2 l S m X 2 n

[0075] In Chemical Formula 1, M 2 is Sn, Mg, Ba, B, Al, Ga, In, Si, Ge, Pb, N, P, As, Sb, Bi, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Hf, Ta, W, or La, and X 2 is F, Cl, Br, I, Se, Te, or O, and 0 < k ≦ 6, 0 < l ≦ 6, 0 < m ≦ 6, and 0 ≦ n ≦ 6.

[0076] For example, in Chemical Formula 1, M 2 may be B, Si, Ge, P, or N.

[0077] For example, in Chemical Formula 1, X 2 may be F, Cl, Br, I, or O.

[0078] For example, the sulfide solid electrolyte represented by Chemical Formula 1 is Li2S - P2S5, Li2S - P2S5 - LiX, where X is a halogen element, Li2S - P2S5 - Li2O, Li2S - P2S5 - Li2O - LiI, Li2S - SiS2, Li2S - SiS2 - LiI, Li2S - SiS2 - LiBr, Li2S - SiS2 - LiCl, Li2S - SiS2 - B2S3 - LiI, Li2S - SiS2 - P2S5 - LiI, Li2S - B2S3, Li2S - P2S5 - Z m S n, m, and n are positive numbers, Z is any one of Ge, Zn, or Ga, Li2S - GeS2, Li2S - SiS2 - Li3PO4, Li2S - SiS2 - Li p MO q , p, and q are positive numbers, M is any one of P, Si, Ge, B, Al, Ga, In, Li 7-x PS 6-x Cl x , 0 ≤ x ≤ 2, Li 7-x PS 6-x Br x , 0 ≤ x ≤ 2, and Li 7-x PS 6-x I x It may be one or more selected from 0 ≤ x ≤ 2.

[0079] Also, preferably, the sulfide - based solid electrolyte may be an argyrodite - type solid electrolyte containing one or more selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0080] The positive electrode can be manufactured according to methods widely known in the art and is not limited to a specific manufacturing method. For example, the positive electrode active material, sulfide - based solid electrolyte, conductive material, binder, etc. can be mixed to prepare a positive electrode mixture paste, which is spray - dried and granulated, and then applied to a positive electrode current collector for manufacturing.

[0081] The positive electrode current collector is generally manufactured with a thickness of 3 - 500 μm. Such a positive electrode current collector is not particularly limited as long as it does not induce chemical changes in the battery and has high conductivity. For example, stainless steel, aluminum, nickel, titanium, fired carbon, or those surface - treated with carbon, nickel, titanium, silver, etc. on the surface of aluminum or stainless steel can be used. The current collector can also form fine irregularities on its surface to enhance the adhesive force of the positive electrode active material, and various forms such as films, sheets, foils, nets, porous bodies, foams, non - woven fabrics, etc. are possible.

[0082] In addition to the positive electrode active material, conductive material, and binder mentioned above, the positive electrode may further contain additives such as fillers, coating agents, dispersants, and ion conductivity enhancers. As the fillers, coating agents, dispersants, and ion conductivity enhancers, known materials commonly used in electrodes for all-solid-state secondary batteries can be used.

[0083] The thickness of the positive electrode may be, for example, 70 to 150 μm.

[0084] The negative electrode may include a negative electrode current collector and a negative electrode mixture layer.

[0085] The thickness of the negative electrode mixture layer is, for example, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5% or less of the thickness of the positive electrode mixture layer. The thickness of the negative electrode active material layer is, for example, 1 μm to 20 μm, 2 μm to 10 μm, or 3 μm to 7 μm.

[0086] The negative electrode mixture layer includes, for example, a negative electrode active material that forms an alloy or compound with lithium.

[0087] The negative electrode active material contained in the negative electrode mixture layer is, for example, particulate. The average particle size of the particulate negative electrode active material is, for example, 4 μm or less, 3 μm or less, 2 μm or less, 1 μm or less, or 900 nm or less. The average particle size of the particulate negative electrode active material is, for example, 10 nm to 4 μm or less, 10 nm to 3 μm or less, 10 nm to 2 μm or less, 10 nm to 1 μm or less, or 10 nm to 900 nm or less.

[0088] The negative electrode active material contained in the negative electrode mixture layer includes, for example, one or more selected from carbon-based negative electrode active materials and metallic or quasi-metallic negative electrode active materials.

[0089] Carbon-based negative electrode active materials are particularly amorphous carbon. Amorphous carbons include, for example, carbon black (CB), acetylene black (AB), furnace black (FB), Ketjen black (KB), and graphene, but are not necessarily limited to these; any material classified as amorphous carbon in the relevant technical field is acceptable. Amorphous carbon is classified as carbon that does not have crystallinity or has very low crystallinity, and is therefore distinguished from crystalline carbon or graphite-based carbon.

[0090] The metallic or quasimetallic anode active material includes, but is not limited to, one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). Any metallic or quasimetallic anode active material that forms an alloy or compound with lithium in the art is acceptable. For example, nickel (Ni) is not a metallic anode active material because it does not form an alloy with lithium.

[0091] The negative electrode mixture layer contains one negative electrode active material from among these negative electrode active materials, or a mixture of multiple different negative electrode active materials. For example, the negative electrode mixture layer contains only amorphous carbon, or one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). Alternatively, the negative electrode active material layer contains a mixture of amorphous carbon and one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). The mixing ratio of amorphous carbon and silver (Ag), etc., is, for example, 10:1 to 1:2, 5:1 to 1:1, or 4:1 to 2:1 by weight, but is not necessarily limited to these ranges.

[0092] The negative electrode active material contained in the negative electrode mixture layer includes, for example, a mixture of first particles made of amorphous carbon and second particles made of a metal or quasimetallic material. Examples of metals or quasimetallic materials include gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). Other quasimetallic materials include semiconductors. The content of the second particles may be 8-60% by weight, 10-50% by weight, 15-40% by weight, or 20-30% by weight, based on the total weight of the mixture.

[0093] The negative electrode mixture layer, like the positive electrode mixture layer, may further contain a conductive material and a binder, the conductive material and binder as described above.

[0094] The negative electrode current collector is composed of a material that does not react with lithium, i.e., does not form any alloys or compounds. The materials constituting the negative electrode current collector include, but are not limited to, copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni), and any other material used as an electrode current collector in the relevant art. The negative electrode current collector can be composed of one of the aforementioned metals, or of an alloy or coating material of two or more metals. The negative electrode current collector may be in the form of a plate or foil, for example.

[0095] The negative electrode mixture layer may further contain additives used in conventional lithium secondary batteries, such as fillers and dispersants.

[0096] When the lithium secondary battery according to the present invention is an all-solid-state battery, it may further include a solid electrolyte layer between the positive electrode and the negative electrode. For example, the solid electrolyte layer may include a sulfide-based solid electrolyte. The sulfide-based solid electrolyte may be the same as or different from the sulfide-based solid electrolyte included in the positive electrode.

[0097] For specific details regarding sulfide-based solid electrolytes, please refer to the positive electrode section described above.

[0098] The elastic modulus (Young's modulus) of the solid electrolyte layer is, for example, 35 GPa or less, 30 GPa or less, 27 GPa or less, 25 GPa or less, or 23 GPa or less. The elastic modulus (Young's modulus) of the solid electrolyte is, for example, 10-35 GPa, 15-35 GPa, 15-30 GPa, or 15-25 GPa. Having an elastic modulus within such a range of elastic modulus of the solid electrolyte layer makes pressurization and / or sintering of the solid electrolyte easier.

[0099] The solid electrolyte layer further includes, for example, a binder. Examples of binders included in the solid electrolyte layer include, but are not limited to, styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, and polyethylene; any binder used in the relevant art is acceptable. The binder in the solid electrolyte layer may be the same as, or different from, the binder in the positive electrode mixture layer and the negative electrode mixture layer.

[0100] The lithium secondary battery according to the present invention can be manufactured, for example, by first manufacturing a positive electrode, a negative electrode, and a solid electrolyte layer, and then stacking these layers.

[0101] The lithium secondary battery according to the present invention can be embodied as a battery module including the lithium secondary battery as a unit battery, a battery pack including the battery module, and a device including the battery pack as a power source.

[0102] Specific examples of the aforementioned devices include, but are not limited to, power tools powered by electric motors; electric vehicles including electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs); electric two-wheeled vehicles including electric bicycles (E-bikes) and electric scooters; electric golf carts; and power storage systems.

[0103] The following describes specific embodiments of the present invention. However, the embodiments described below are merely for illustrative or explanatory purposes and do not limit the present invention. Furthermore, matters not described herein can be sufficiently inferred by technical analogy to those skilled in the art, and their explanations are omitted.

[0104] Manufacturing Example 1: Manufacturing of Electrode Mixture Layer Particles (1) A slurry with a viscosity of approximately 1,000 cPs was prepared by mixing 94 wt% of a positive electrode active material containing nickel, cobalt, and manganese in a weight ratio of 8:1:1, 1 wt% of a carbon black conductive material, and 5 wt% of a polytetrafluoroethylene (PTFE) binder with water as a dispersion medium, and then homogenizing the mixture. At this time, the solid content in the slurry was 30 wt%.

[0105] (2) The slurry produced above was introduced into a spray dryer along with hot air under pressure range conditions of -40 mmH2O, and dried to produce granular electrode mixture layer particles. At this time, the spray dryer conditions were controlled with an inlet temperature of 180°C, an outlet temperature of 90°C, and a rotation speed of 18,000 rpm. The average particle size (D50) of the granular particles obtained above was measured using a particle size analyzer, and their morphology was measured using a scanning electron microscope (SEM), and the results are shown in Figure 4.

[0106] Manufacturing Examples 2-6: Manufacturing of Electrode Mixture Layer Particles In Manufacturing Example 1, granular electrode mixture layer particles were produced in the same manner as in Manufacturing Example 1, except that the content of the positive electrode active material, conductive material, binder, and spray drying time were as shown in Table 1 below. The average particle size (D50) of the electrode mixture layer particles produced in Manufacturing Example 2 was measured using a particle size analyzer, and their morphology was measured using a scanning electron microscope (SEM). The results are shown in Figure 5. The average particle size (D50) of the particles produced in Manufacturing Examples 3 to 6 was also measured using the same method and is shown in Table 1 below.

[0107] [Table 1]

[0108] Example 1: Manufacturing of electrode plates for lithium secondary batteries Using a thickness adjustment bar on one surface of the current collector layer formed of aluminum foil, the current collector is 25 cm 2 Granule-like electrode mixture layer particles produced in Production Example 1 and Production Example 5 were applied to the current collector in varying areas at a rate of 400 mg per unit. The mixture was then pressurized at a rate of 2 m / min under conditions of 0.7 tons per cm, 60°C, and using a roll-to-roll hot rolling machine to produce an electrode plate for a lithium secondary battery formed on the current collector layer. The results are shown in Figure 6.

[0109] Specifically, using one edge portion of the generated electrode mixture layer and the lateral cross-section of the electrode mixture layer as a reference, the electrode mixture layer particles produced in Production Example 1 were applied to the other edge portion formed on the other side, and the electrode mixture layer particles produced in Production Example 5 were applied to the area of ​​the electrode mixture layer excluding the two edge portions, so that granular particles with a high binder content could be positioned at the edge portions of the electrode mixture layer. The two edge portions were formed with an area of ​​30% of the total area of ​​the electrode mixture layer.

[0110] Referring to Figure 6, it can be seen that the aluminum foil wrinkles slightly at the edges of the electrode mixture layer due to increased stress. However, because electrode mixture layer particles with a high binder content are located at the edges of the electrode mixture layer, the electrode mixture layer is not detached from the current collector, and stable sheeting of the electrode mixture layer is possible.

[0111] Example 2: Manufacturing of electrode plates for lithium secondary batteries In the above-mentioned Example 1, an electrode plate for a lithium secondary battery was manufactured in the same manner as in Example 1, except that the electrode mixture layer particles manufactured in Manufacturing Example 2 were applied to two edges of the electrode mixture layer, and the result is shown in Figure 7.

[0112] Referring to Figure 7, it can be seen that by arranging high-binder particles with a smaller average particle size compared to Example 1, the stress at the edges of the electrode mixture layer was reduced, and the phenomenon of wrinkling of the aluminum foil was relatively reduced.

[0113] Example 3: Manufacturing of electrode plates for lithium secondary batteries Except for applying the electrode mixture layer particles manufactured in Manufacturing Example 4 to two edges of the electrode mixture layer in Example 1, an electrode plate for a lithium secondary battery was manufactured in the same manner as in Example 1, and the result is shown in Figure 8.

[0114] Referring to Figure 8, it can be seen that, compared to the high-binder particles used in Example 2, using particles manufactured with a higher drying rate for granular particle production resulted in a significant reduction in the wrinkling of the aluminum foil, and further improvement in the adhesion between the current collector and the electrode mixture layer. This can be understood as a result of increasing the drying rate during the production of granular particles compared to Manufacturing Example 1 or 2, which caused the binder components within the particles to migrate to the surface layer of the particles along with the evaporation of the dispersion medium, thereby improving the adhesion performance of the particles.

[0115] Figure 9 shows a scanning electron microscope (SEM) image of the lithium secondary battery electrode plate according to this embodiment 3, and Figure 10 shows a carbon EDS mapping image of the lithium secondary battery electrode plate according to the above embodiment 3.

[0116] Referring to Figures 9 and 10, it can be seen from the carbon EDS mapping image of the lithium secondary battery electrode plate that, in the case of the lithium secondary battery electrode plate according to Example 3, granular particles in which the binder has migrated to the surface layer of the particles were applied to the edge of the electrode mixture layer.

[0117] Comparative Example 1: Manufacturing of electrode plates for lithium secondary batteries Using a thickness adjustment bar on one surface of the current collector layer formed of aluminum foil, the current collector is 25 cm 2 A granular electrode mixture layer particle, manufactured in Manufacturing Example 1, was applied to a current collector at a rate of 400 mg per unit area. The mixture was then pressurized in a roll-to-roll hot rolling machine at a pressure of 0.7 tons per cm, a temperature of 60°C, and a speed of 2 m / min to produce an electrode plate for a lithium secondary battery formed on the current collector layer. The results are shown in Figure 3B).

[0118] Referring to Figure 3B), when an electrode mixture layer was formed using a single particle manufactured in Manufacturing Example 1, the adhesion between the current collector and the electrode mixture layer was at a good level. However, as a result of increased stress at the edges of the electrode mixture layer, the phenomenon of wrinkling in the aluminum foil was observed.

[0119] Comparative Example 2: Manufacturing of electrode plates for lithium secondary batteries In Comparative Example 1, a lithium secondary battery electrode plate was manufactured in the same manner as in Comparative Example 1, except that particles manufactured in Manufacturing Example 2 were applied instead of the particles manufactured in Manufacturing Example 1. The results are shown in Figure 3C).

[0120] Referring to Figure 3C), when an electrode mixture layer was formed using a single particle manufactured in Manufacturing Example 2, it was confirmed that the average particle size was relatively smaller compared to the particle manufactured in Manufacturing Example 1, the binder content located on the surface of the particle decreased, and as a result of the reduced adhesive strength, the packing of the electrode mixture layer did not proceed smoothly.

[0121] Comparative Example 3: Manufacturing of electrode plates for lithium secondary batteries In Comparative Example 1, a lithium secondary battery electrode plate was manufactured in the same manner as in Comparative Example 1, except that particles manufactured in Manufacturing Example 4 were applied instead of the particles manufactured in Manufacturing Example 1. The results are shown in Figure 3D).

[0122] Referring to Figure 3D), when an electrode mixture layer was formed using a single particle manufactured in Manufacturing Example 4, the adhesion between the current collector layer and the electrode mixture layer increased slightly compared to the electrode plate in Comparative Example 2, but it was confirmed that the packing of the electrode mixture layer was still not performed smoothly.

[0123] Comparative Example 4: Manufacturing of electrode plates for lithium secondary batteries In Comparative Example 1, a lithium secondary battery electrode plate was manufactured in the same manner as in Comparative Example 1, except that particles manufactured in Manufacturing Example 5 were applied instead of the particles manufactured in Manufacturing Example 1. The results are shown in Figure 3A).

[0124] Referring to Figure 3A), when an electrode mixture layer was formed using a single particle manufactured in Manufacturing Example 5, the binder content within the particle was significantly reduced compared to the particle manufactured in Manufacturing Example 1, and it was confirmed that the adhesive strength between the current collector and the electrode mixture layer was significantly reduced.

[0125] Experimental example: Evaluation of initial discharge capacity, high-rate discharge characteristics, and life characteristics of lithium secondary batteries. The initial discharge capacity, high-rate discharge characteristics, and life characteristics of the all-solid-state batteries including the electrode plates according to Examples 1-3, Comparative Example 1, and Comparative Example 4 were evaluated.

[0126] The aforementioned all-solid-state battery was manufactured by the following method.

[0127] After loading 150 mg of Li6PS5Cl as a solid electrolyte into a mold cell, it is pelletized at a pressure of 70 MPa. The electrode plates according to Examples 1 to 3, Comparative Example 1, and Comparative Example 4 thus produced are loaded as the positive electrode on one side of the solid electrolyte pellet, and Li 0.5 100 mg of a composite negative electrode in which In and the solid electrolyte are mixed at a weight ratio of 8:2 is loaded and pressurized at a pressure of 370 MPa to fabricate an all-solid-state half-cell. The fastening strength of the bolts of the jig is fastened so that a driving pressure of 70 MPa is applied. For the evaluation of the all-solid-state half-cell, after sealing so that air does not penetrate into the battery, it is transferred to a constant temperature chamber and the following electrochemical evaluation is performed.

[0128] Regarding the all-solid-state batteries including the electrode plates according to Examples 1 to 3, Comparative Example 1, and Comparative Example 4, the initial discharge capacity was evaluated by the following test method. After charging at a rate of 0.1C (C-rate) until the voltage reached 4.3V (vs. Li), it was cut off at 4.3V (vs. Li). Subsequently, it was discharged at a rate of 0.1C (C-rate) until the voltage reached 3.0V (vs. Li) during discharge (1 st cycle). The results are shown in Table 2 below.

[0129] Regarding the all-solid-state batteries including the electrode plates according to Examples 1 to 3, Comparative Example 1, and Comparative Example 4, the high-rate discharge characteristics were evaluated by the following test method. After charging under constant current (0.1C) and constant voltage (1.0V, 0.01C cut-off) conditions, it was rested for 10 minutes and then discharged under constant current (3.0C) conditions until it reached 2.5V. The high-rate discharge characteristics at this time are shown in Table 2 below.

[0130] In Table 2 below, the high-rate discharge characteristics can be calculated by the following Mathematical Formula 1.

[0131] [Mathematical Formula 1] High-rate discharge characteristics (%) = (Discharge capacity when discharging the cell at 3.0C) / (Discharge capacity when discharging the cell at a rate of 0.1C) * 100

[0132] The life characteristics of the all-solid-state batteries, including the electrode plates, according to Examples 1-3, Comparative Example 1, and Comparative Example 4 were evaluated using the following test method. 100 charge-discharge cycles were performed under constant current (1C) and constant voltage (1.0V, 0.01C cut-off) charging, 10-minute rest, and constant current (1C, room temperature (20°C), 2.5V cut-off) discharge conditions. The discharge capacity after 100 cycles relative to the initial discharge capacity was measured to determine the life characteristics. The life characteristics at this time are shown in Table 2 below.

[0133] [Table 2]

[0134] Referring to Table 2 above, it can be seen that when applying high-binder particles to the electrode mixture layer, the all-solid-state battery including the electrode mixture layer according to Example 3, which uses particles with a relatively small average particle size and a fast drying rate for particle manufacturing, exhibits the best initial discharge capacity, high-rate discharge characteristics, and life characteristics. [Explanation of symbols]

[0135] 10, 11, 13: 1st area 20:Second area 30: 1st particle 40:Second particle 50: Edge portion of the electrode mixture layer 60: First edge portion of the electrode mixture layer 70: Second edge portion of the electrode mixture layer 100, 200: Electrode plates for lithium secondary batteries

Claims

1. Current collector layer; and The current collector layer includes an electrode mixture layer formed on one or both sides thereof. The electrode mixture layer includes a first region formed in the direction of the other edge portion with respect to the transverse (TD) cross-section of the electrode mixture layer, and a second region excluding the first region. The electrode mixture layer comprises first and second particles, each containing an electrode active material, a conductive material, and a binder, respectively. The first particle has a higher binder content than the second particle, or the region containing 30% or more of the total binder content within the particle is 20% or less of the length from the outermost surface of the particle to the center of the particle. Electrode plates for lithium secondary batteries.

2. The first particle is included in the first region, The second particle is included in the second region. The electrode plate for a lithium secondary battery according to claim 1.

3. The first and second particles are granular. The electrode plate for a lithium secondary battery according to claim 1.

4. The average particle sizes of the first and second particles are 30 μm to 100 μm, respectively. The electrode plate for a lithium secondary battery according to claim 1.

5. The first region is formed with an area ratio of 1% to 20% based on the total area of ​​the electrode mixture layer. The electrode plate for a lithium secondary battery according to claim 1.

6. The binder content ratio of the first particle to the binder content ratio of the second particle is 1.2:1 to 3.0:

1. The electrode plate for a lithium secondary battery according to claim 1.

7. The binder contained in the first and second particles is at least one of the following: polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyethylene (PE), high molecular weight polyethylene (HMWPE), ultra-high molecular weight polyethylene (UHMWPE), polypropylene (PP), carboxymethylcellulose (CMC), polyvinylphenol, polyvinylpyrrolidine, polyvinyl acetate, polyvinyl alcohol, and polyacetylene. The electrode plate for a lithium secondary battery according to claim 1.

8. The first particle contains 3.6% to 9% by weight of a binder relative to the total weight of the first particle. The second particle contains 1% to 5% by weight of a binder relative to the total weight of the second particle. The electrode plate for a lithium secondary battery according to claim 1.

9. The first and second particles each independently contain a sulfide-based solid electrolyte represented by the following chemical formula 1. Electrode plate for lithium secondary battery according to claim 1: [Chemical formula 1] Li ｋ M ２ ｌ S ｍ X ２ ｎ In the above chemical formula 1, M ２ is Sn, Mg, Ba, B, Al, Ga, In, Si, Ge, Pb, N, P, As, Sb, Bi, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Hf, Ta, W, or La; ２ is F, Cl, Br, I, Se, Te, or O, and 0 < k ≤ 6, 0 < l ≤ 6, 0 < m ≤ 6, and 0 ≤ n ≤ 6.

10. A lithium secondary battery comprising an electrode plate for a lithium secondary battery as described in any one of claims 1 to 9.

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