electrode

Abstract

To lower an increase in interface resistance.SOLUTION: An electrode comprises current-collecting foil, and an active material layer including a plurality of binder particles and a plurality of active material particles. The plurality of binder particles, which adhere to a surface of the current-collecting foil, are randomly distributed on the surface of the current-collecting foil. Interface resistance between the current-collecting foil and the active material layer is 0.004 Ω / cm2 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to electrodes for lithium ion batteries and methods for manufacturing the same. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2016-122631 (Patent Document 1) discloses forming a binder coat layer on a current collector. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-122631 Summary of the Invention [Problem to be solved by the invention]

[0004] An electrode for a lithium-ion battery (hereinafter, simply referred to as "electrode") can be manufactured by forming an active material layer on the surface of a current collector foil. In order to increase the peel strength between the active material layer and the current collector foil, it is considered to form a binder film between the active material layer and the current collector foil.

[0005] Conventionally, binder films are formed by a wet method. That is, a binder solution is applied to the surface of the current collector foil to form the binder film. The binder film covers the surface of the current collector foil. The binder is a resistive component. The presence of a binder film between the current collector foil and the active material layer can increase the interfacial resistance (electronic resistance) between the current collector foil and the active material layer.

[0006] The objective of the present disclosure is to mitigate the increase in interfacial resistance. [Means for solving the problem]

[0007] The technical configuration and effects of the present disclosure will be described below. However, the mechanism of action in this specification includes speculation. The mechanism of action does not limit the technical scope of the present disclosure.

[0008] 1. An electrode for a lithium-ion battery includes a current collector foil, a binder particle group, and an active material layer. The binder particle group is attached to the surface of the current collector foil. The active material layer is disposed on the surface of the current collector foil. The active material layer includes an active material particle group. The binder particle group is scattered at the interface between the active material layer and the current collector foil.

[0009] In the electrode of "1" above, binder particle groups are scattered at the interface between the active material layer and the current collector foil. Because the binder is in particulate form rather than film form, many active material particles can come into contact with the current collector foil at the interface between the active material layer and the current collector foil. This can reduce the increase in interface resistance that accompanies the use of a binder.

[0010] When a binder film is formed on the surface of a current collector foil, it is thought that the number of contact points between the binder film (surface) and the active material particles is likely to be small. On the other hand, the binder particles may come into point contact with the active material particles. If the binder is particulate, the number of contact points between the binder and the active material particles may increase. By using binder particle groups instead of a binder film, it is expected that high peel strength can be obtained with a low binder basis weight.

[0011] 2. The ratio of the adhesion area of ​​the binder particle group to the area of ​​the current collector foil may be, for example, 11.4 to 19.3%.

[0012] Hereinafter, "the ratio of the adhesion area of ​​the binder particle group to the area of ​​the current collector foil" may be abbreviated as "area fraction." When the area fraction is 11.4% or more, improved peel strength is expected. When the area fraction is 19.3% or less, reduced interfacial resistance is expected.

[0013] 3. The binder particles may have a smaller D50 than, for example, the active material particles.

[0014] When the size of the binder particles is smaller than the size of the active material particles, the number of contact points between the active material particles and the current collector foil can be increased, which is expected to reduce the interface resistance.

[0015] 4. The binder particle group is, for example, 0.010 to 0.017 mg / cm 2 The fiber may have a basis weight of 1000 or more.

[0016] 5. A method for producing an electrode for a lithium ion battery includes the following steps (a) to (c): (a) Prepare the current collecting foil. (b) Binder particles are applied to the surface of the current collector foil by a dry method. (c) After (b) above, an active material layer is formed by applying an active material particle group to the surface of the current collector foil.

[0017] When the binder particles are applied by a dry method, a binder film is not formed, and the binder particles may become scattered.

[0018] 6. The above step (b) may include attaching the binder particles to the surface of the current collector foil by electrostatic force.

[0019] As an example of a dry method, it is conceivable to attach binder particles to a current collector foil by electrostatic force.

[0020] 7. The above (c) may include applying the active material particles by a dry method.

[0021] For example, when the active material particles are applied by a wet method, the arrangement of the binder particles may change. However, when the active material particles are also applied by a dry method, it is thought that the dispersed state of the binder particles is more likely to be maintained.

[0022] Hereinafter, an embodiment of the present disclosure (hereinafter may be abbreviated as "the present embodiment") and an example of the present disclosure (hereinafter may be abbreviated as "the present example") will be described. However, the present embodiment and the example do not limit the technical scope of the present disclosure. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a conceptual cross-sectional view of a lithium ion battery electrode according to this embodiment. [Figure 2] FIG. 2 is a conceptual top view of the binder particle group. [Figure 3] FIG. 3 is a conceptual top view of the binder film. [Figure 4] FIG. 4 is a conceptual cross-sectional view of a binder film. [Figure 5] FIG. 5 is a schematic flowchart of a method for producing an electrode for a lithium ion battery according to this embodiment. [Figure 6] FIG. 6 is a conceptual diagram showing an example of a method for applying binder particles. [Figure 7] FIG. 7 is a graph showing the relationship between the binder basis weight and the interface resistance. [Figure 8] FIG. 8 is a graph showing the relationship between the binder basis weight and the peel strength. DETAILED DESCRIPTION OF THE INVENTION

[0024] <Definitions of terms, etc.> In this specification, the terms "comprise," "include," "have," and variations thereof (e.g., "consisting of") are open-ended. Open-ended terms may or may not include additional elements in addition to the required elements. The term "consisting of" is closed-ended. However, even in closed-ended terms, additional elements that are normally incidental impurities or unrelated to the disclosed technology are not excluded. The term "consisting essentially of..." is semi-closed. Semi-closed terms allow for the addition of elements that do not substantially affect the basic and novel characteristics of the disclosed technology.

[0025] In this specification, expressions such as "may" and "can" are used in the permissive sense of "possibly" rather than the obligatory sense of "must."

[0026] In this specification, unless otherwise specified, a numerical range such as "m to n%" includes both the upper and lower limits. That is, "m to n%" indicates a numerical range of "m% or more and n% or less." Furthermore, "m% or more and n% or less" includes "more than m% and less than n%." Furthermore, a numerical value arbitrarily selected from within the numerical range may be set as a new upper or lower limit. For example, a new numerical range may be set by arbitrarily combining a numerical value within the numerical range with a numerical value described elsewhere in this specification, in a table, a figure, or the like.

[0027] In this specification, all numerical values ​​are modified by the term "about." The term "about" may mean, for example, ±5%, ±3%, ±1%, etc. All numerical values ​​may be approximate values ​​that may vary depending on the application of the disclosed technology. All numerical values ​​may be expressed with significant figures. Measured values ​​may be the average value of multiple measurements. The number of measurements may be three or more, five or more, or ten or more. In general, the more measurements are made, the more reliable the average value is expected to be. Measured values ​​may be rounded off based on the number of significant figures. Measured values ​​may include errors, such as those associated with the detection limits of the measuring device.

[0028] In this specification, when a compound is expressed by a stoichiometric formula (e.g., "LiCoO2"), the stoichiometric formula is merely a representative example of the compound. The compound may have a non-stoichiometric composition. For example, when lithium cobalt oxide is expressed as "LiCoO2," unless otherwise specified, the lithium cobalt oxide is not limited to a composition ratio of "Li / Co / O = 1 / 1 / 2" and may contain Li, Co, and O in any composition ratio. Furthermore, doping or substitution with trace elements may be permitted.

[0029] In this specification, the order of execution of multiple steps, actions, operations, etc. included in various methods is not limited to the order described unless otherwise specified. For example, multiple steps may proceed simultaneously. For example, multiple steps may occur one after the other.

[0030] In this specification, the term "electrode" is a general term for positive electrodes and negative electrodes. The electrode may be a positive electrode or a negative electrode.

[0031] In this specification, "D50" refers to the particle size at which the cumulative frequency of smaller particle sizes reaches 50% in a volume-based particle size distribution. The volume-based particle size distribution can be determined, for example, by a laser diffraction / scattering method.

[0032] In this specification, the term "dry method" refers to a coating method in which the solid content of the paint is 90% or more. The solid content of the paint in the dry method may be, for example, 95 to 100%. The term "wet method" refers to a coating method in which the solid content of the paint is less than 90%. The solid content of the paint in the wet method may be, for example, 50 to 85%. The "solid content" refers to the mass fraction of solid components relative to the total paint.

[0033] <Electrodes for lithium-ion batteries> FIG. 1 is a conceptual cross-sectional view of a lithium-ion battery electrode according to this embodiment. Hereinafter, the "lithium-ion battery electrode according to this embodiment" may be abbreviated as "the electrode." The electrode 10 is sheet-shaped. The electrode 10 includes a current collector foil 11, a binder particle group 12, and an active material layer 13. The binder particle group 12 and the active material layer 13 may be disposed on only one side of the current collector foil 11, or on both the front and back sides of the current collector foil 11.

[0034] The electrode 10 can have high peel strength. The peel strength between the active material layer 13 and the current collector foil 11 can be, for example, 1 N / m or more. The peel strength between the active material layer 13 and the current collector foil 11 can be, for example, 1 to 3.5 N / m. The electrode 10 can have low interface resistance. The interface resistance between the active material layer 13 and the current collector foil 11 can be, for example, 0.0033 Ω / cm 2 The interface resistance between the active material layer 13 and the current collector foil 11 may be, for example, 0.0011 to 0.0033 Ω / cm 2 may be.

[0035] Current-collecting foil The current collector foil 11 is conductive. The current collector foil 11 is in a sheet form. The current collector foil 11 supports the active material layer 13. The current collector foil 11 includes a metal foil. The current collector foil 11 may include at least one type selected from the group consisting of aluminum foil, aluminum alloy foil, copper foil, copper alloy foil, nickel foil, titanium foil, and stainless steel foil. The current collector foil 11 may have a thickness of, for example, 5 to 50 μm, or 10 to 25 μm.

[0036] <Binder particle group> The binder particle group 12 is scattered at the interface between the active material layer 13 and the current collector foil 11. FIG. 2 is a conceptual top view of the binder particle group. The binder particle group 12 is attached to the surface of the current collector foil 11. The binder particle group 12 is distributed in an island-like pattern on the surface of the current collector foil 11. Each island-like portion may be a single binder particle or an aggregate of multiple binder particles. The island-like portions may be distributed regularly or randomly. It is believed that the active material particles can come into contact with the current collector foil 11 in the gaps between the island-like portions. The gaps between the island-like portions may be, for example, the size of one binder particle or more.

[0037] On the surface of the current collecting foil 11, the binder particle group 12 has a density of, for example, 0.010 to 0.017 mg / cm 2 The binder particle group 12 may have a weight per unit area of, for example, 0.010 to 0.014 mg / cm. The weight per unit area indicates the mass (adhesion amount) per unit area. 2 or 0.014 to 0.017 mg / cm 2 The fiber may have a basis weight of 1000 or more.

[0038] On the surface of the current collector foil 11, the binder particle group 12 may have an area fraction of, for example, 50% or less, 30% or less, or 20% or less. The binder particle group 12 may have an area fraction of, for example, 11.4 to 19.3%. When the area fraction is 11.4% or more, improved peel strength is expected. When the area fraction is 19.3% or less, reduced interfacial resistance is expected. The binder particle group 12 may have an area fraction of, for example, 11.4 to 15.9%, or 15.9 to 19.3%.

[0039] The area fraction is calculated by the following formulas (I) to (IV). M=c×S0…(I) V=M÷ρ …(II) S1=V÷T …(III) F = S1 ÷ S0 × 100 …(IV) "M" indicates the mass [mg] of the binder particle group. "c" is the basis weight of the binder particles [mg / cm 2 ] is shown. "S0" is the area of ​​the current collecting foil [cm 2 ] is shown. "V" is the volume of the binder particles [cm 3 ] is shown. "ρ" is the density of the binder particles [g / cm 3 ] is shown. "T" indicates the coating thickness [μm] of the binder particle group. "F" indicates the area fraction [%].

[0040] 3 is a conceptual top view of the binder film. Binder film 14 covers the surface of current collector foil 11. To form contact points between the active material particles and current collector foil 11, binder film 14 may be arranged, for example, in a stripe pattern.

[0041] 4 is a conceptual cross-sectional view of a binder film. The active material particles come into contact with the current collector foil 11 in the gaps between the binder films 14. However, it is thought that the active material particles arranged on the binder film 14 are unlikely to come into contact with the current collector foil 11. Even if the binder film 14 is formed in a striped pattern, it is thought that the desired interface resistance cannot be obtained.

[0042] The binder particle group 12 is an aggregate of a plurality of binder particles. The binder particle group 12 may have a D50 of, for example, 10 to 1000 nm, 50 to 500 nm, or 100 to 200 nm. The binder particle group 12 may have a smaller D50 than the active material particle group. When the size of the binder particles is smaller than the size of the active material particles, the number of contact points between the active material particles and the current collector foil 11 can be increased. This is expected to reduce the interfacial resistance. The D50 of the binder particle group 12 may be 1 / 10 or less, or 1 / 20 or less, of the D50 of the active material particle group. The D50 of the binder particle group 12 may be 1 / 100 or more of the D50 of the active material particle group.

[0043] The binder particles may contain any component, for example, at least one selected from the group consisting of polyvinylidene fluoride (PVdF), vinylidene fluoride-hexafluoropropylene copolymer (PVdF-HFP), styrene-butadiene rubber (SBR), carboxymethyl cellulose (CMC), polyacrylic acid (PAA), polyamideimide (PAI), and polyimide (PI).

[0044] 《Active material layer》 The active material layer 13 is disposed on the surface of the current collector foil 11. The active material layer 13 may have a thickness of, for example, 10 to 500 μm, or 50 to 200 μm. The active material layer 13 contains active material particle groups. In addition to the active material particle groups, the active material layer 13 may further contain a conductive material, a binder, a solid electrolyte, etc.

[0045] <Active material particle group> The active material particle group is an aggregate of a plurality of active material particles. The active material particle group may have a D50 of, for example, 1 to 30 μm, or may have a D50 of 3 to 10 μm.

[0046] The active material particles may contain, for example, a positive electrode active material. The active material particles may contain, for example, at least one selected from the group consisting of LiCoO2, LiNiO2, LiMnO2, LiMn2O4, Li(NiCoMn)O2, Li(NiCoAl)O2, and LiFePO4. For example, "(NiCoMn)" in "Li(NiCoMn)O2" indicates that the sum of the composition ratios in parentheses is 1. As long as the sum is 1, the amount of each component is arbitrary. Li(NiCoMn)O2 may be, for example, Li(Ni 1 / 3 Co 1 / 3 Mn 1 / 3 )O2, Li(Ni 0.5 Co 0.2 Mn 0.3 )O2, Li(Ni 0.8 Co 0.1 Mn 0.1 ) O2, etc.

[0047] The active material particles may include, for example, a negative electrode active material, such as graphite, soft carbon, hard carbon, silicon, silicon oxide, a silicon-based alloy, tin, tin oxide, a tin-based alloy, and Li4Ti5O 12 It may contain at least one selected from the group consisting of:

[0048] <Other ingredients> The active material layer 13 may further contain a binder. The amount of the binder may be, for example, 0.1 to 10 parts by mass with respect to 100 parts by mass of the active material particles. The binder contained in the active material layer 13 may be in the form of particles or a film. The binder may contain, for example, PVdF, CMC, SBR, etc.

[0049] The active material layer 13 may further contain a conductive material. The amount of the conductive material may be, for example, 0.1 to 10 parts by mass per 100 parts by mass of the active material particles. The conductive material may include, for example, conductive carbon particles, conductive carbon fibers, etc. The conductive material may include, for example, at least one material selected from the group consisting of carbon black, vapor-grown carbon fiber, carbon nanotubes, and graphene flakes. The carbon black may include, for example, at least one material selected from the group consisting of acetylene black, furnace black, channel black, and thermal black.

[0050] Active material layer 13 may further contain a solid electrolyte. The solid electrolyte may contain, for example, at least one selected from the group consisting of Li2S—P2S5, LiI—Li2S—P2S5, LiBr—Li2S—P2S5, and LiI—LiBr—Li2S—P2S5.

[0051] 〈Composition〉 For example, active material particles may be composited with other solid materials (binders, conductive materials, etc.). For example, composite particles may be formed by mixing active material particles with other solid materials under conditions where a strong shear force is applied. In the composite particles, for example, binders and conductive materials may be attached to the surfaces of the active material particles.

[0052] <Method of manufacturing electrodes for lithium-ion batteries> 5 is a schematic flowchart of a method for manufacturing a lithium-ion battery electrode according to this embodiment. Hereinafter, the "method for manufacturing a lithium-ion battery electrode according to this embodiment" may be abbreviated as "the present manufacturing method." The present manufacturing method includes "(a) preparation of a current collector foil," "(b) application of binder particles," and "(c) application of active material particles." The present manufacturing method may further include, for example, "(d) fixing."

[0053] (a) Preparation of current collecting foil This manufacturing method includes preparing a current collector foil 11. Details of the current collector foil 11 are as described above.

[0054] (b) Application of binder particles This manufacturing method includes applying binder particles 12 (powder) by a dry method to the surface of the current collector foil 11. For example, electrostatic printing, electrostatic painting, or similar techniques may be used.

[0055] FIG. 6 is a conceptual diagram showing an example of a method for applying binder particles. For example, the binder particles may be applied by electrostatic screen printing. The binder particles 12 are disposed on a screen 101. The screen 101 is conductive. A plurality of through holes are formed in the screen 101. A current collector foil 11 is disposed below the screen 101. A power source 102 applies a DC voltage between the current collector foil 11 and the screen 101. This forms an electric field (E) between the screen 101 and the current collector foil 11. An electric charge (q) is injected from the screen 101 into the binder particles 12. In other words, the binder particles 12 are charged. A printing brush 103 smooths the binder particles 12, thereby introducing the binder particles 12 into the electric field. In the electric field, an electrostatic force (F=qE) acts on the binder particles 12. The electrostatic force can cause the binder particles 12 to adhere to the surface of the current collector foil 11. For example, the application pattern can be controlled by the pattern of through holes in the screen 101. That is, a desired scattering state can be formed.

[0056] The coating thickness (deposited thickness) of the binder particle group 12 may be, for example, 0.1 to 3 μm, or 0.1 to 1 μm.

[0057] (c) Coating of active material particles This manufacturing method includes applying the binder particles 12 and then applying active material particles (powder) to the surface of the current collector foil 11 to form the active material layer 13.

[0058] The active material particles may be applied by any method. For example, a slurry containing the active material particles may be prepared. The slurry may be applied to the surface of the current collector foil 11 using, for example, a die coater. For example, a wet powder containing the active material particles may be prepared. The wet powder may be applied to the surface of the current collector foil 11 using, for example, a roll coater. The wet powder is sometimes referred to as a granule.

[0059] As with the binder particles, the active material particles may also be applied by a dry method. It is believed that by applying the active material particles by a dry method, the dispersed state of the binder particles is more likely to be maintained.

[0060] For example, composite particles may be formed by combining active material particles, a conductive material, and a binder. By applying a composite particle group (powder) by a dry method, an active material layer 13 having a homogeneous composition can be formed. This is thought to be because the positional relationship between the active material particles, the conductive material, and the binder is unlikely to change during the process of forming the active material layer 13. In a wet method, for example, the binder moves with the solvent (liquid) during the process of forming the active material layer 13, which tends to cause bias in the composition.

[0061] (d) Establishment The present manufacturing method may include applying at least one of heat and pressure to active material layer 13 to fix active material layer 13 to current collector foil 11. Fixing active material layer 13 to current collector foil 11 is expected to improve peel strength.

[0062] Pressure and heat may be applied separately. Pressure and heat may be applied substantially simultaneously. For example, active material layer 13 may be compressed using a heat roll, a heat plate, or the like. The heating temperature of active material layer 13 may be, for example, a temperature near the melting point of the binder. The heating temperature may be, for example, 80 to 200°C, 120 to 200°C, or 140 to 180°C.

[0063] The pressure can be adjusted according to, for example, the target thickness and target density of active material layer 13. For example, a pressure of 50 to 200 MPa may be applied to active material layer 13.

[0064] In this way, the present electrode 10 can be manufactured. The present electrode 10 may be cut into a predetermined planar shape according to the specifications of the battery. [Example]

[0065] <Electrode manufacturing> Electrodes Nos. 1 to 5 were manufactured as follows.

[0066] No. 1 The following materials were prepared: Active material particles: Li(NiCoMn)O2, particle size range = 3 to 10 μm Conductive material: acetylene black Binder particle group: PVdF, D50=150nm, density=1.76g / cm 3 Current collecting foil: Al foil, thickness = 12 μm

[0067] An electrostatic screen printing machine (manufactured by Berg Kogyo Co., Ltd.) was prepared. The distance between the screen 101 and the current collector foil 11 was set to 1 cm. A DC voltage of 1.5 kV was applied between the screen 101 and the current collector foil 11 to form an electric field. Binder particles 12 were applied to the surface of the current collector foil 11 by electrostatic screen printing (see FIG. 6). That is, the binder particles 12 were applied by a dry method. The basis weight of the binder particles 12 was 0.007 mg / cm. 2 The coating thickness of the binder particles 12 was 0.5 μm.

[0068] A mixing device called the "Multi-Purpose Mixer" manufactured by Nippon Coke Engineering Co., Ltd. was prepared. The device includes a spherical tank (mixing vessel). The spherical tank's convection-promoting effect generates strong shear forces, allowing solid materials to be compounded.

[0069] Active material particles, conductive material, and binder were placed in a spherical tank. The material mixing ratio was "active material particles / conductive material / binder = 90 / 5 / 5 (mass ratio)." The rotation speed of the stirring blade was set to 10,000 rpm. The materials were mixed for 10 minutes. Composite particles were formed by the conductive material and binder adhering to the surface of the active material particles.

[0070] The composite particle group was applied to the surface of the current collector foil 11 by electrostatic screen printing (dry method), thereby forming the active material layer 13. In other words, the present electrode 10 was manufactured.

[0071] This electrode 10 was sandwiched between two heat plates (flat plates). The temperature of the heat plates was 160° C. A load of 15 tf was applied to the active material layer 13 by the heat plates. This fixed the active material layer 13 to the current collector foil 11.

[0072] No.2~4 As shown in Table 1 below, except that the basis weight of the binder particle group 12 was changed, the present electrode 10 was produced in the same manner as No. 1, and the active material layer 13 was fixed.

[0073] No.5 A binder solution was prepared by dissolving binder particles in a solvent. The binder solution was applied in stripes to the surface of the current collector foil 11 (see Figures 3 and 4). This formed a binder film 14. Except for these steps, an electrode was manufactured in the same manner as No. 1.

[0074] <Electrode evaluation> The peel strength between the active material layer 13 and the current collector foil 11 was measured by a 90-degree peel test.

[0075] The interface resistance between the active material layer 13 and the current collecting foil 11 was measured using an electrode resistance measuring system (model name "RM2610", manufactured by HIOKI Corporation).

[0076] [Table 1]

[0077] 7 is a graph showing the relationship between the binder basis weight and the interface resistance. As the binder basis weight increases, the interface resistance tends to increase.

[0078] FIG. 8 is a graph showing the relationship between the binder basis weight and peel strength. When the binder particles are applied dry, there is a tendency for high peel strength to be obtained with a low basis weight. In other words, the dry method can reduce the binder basis weight compared to the wet method. Therefore, it is thought that applying the binder particles dry can reduce the increase in interface resistance (see FIG. 7).

[0079] <Additional Notes> This specification also supports a lithium ion battery. The lithium ion battery includes the present electrode. The lithium ion battery is expected to have low battery resistance. This is because the interface resistance between the active material layer and the current collecting foil in the present electrode is low. The lithium ion battery may be a liquid-based battery or an all-solid-state battery.

[0080] The present embodiment and examples are illustrative in all respects. The present embodiment and examples are not limiting. The technical scope of the present disclosure encompasses all modifications within the meaning and scope equivalent to the claims. For example, it is also intended from the beginning that any configuration may be extracted from the present embodiment and examples and that they may be combined in any desired manner. [Explanation of symbols]

[0081] 10 electrode (lithium ion battery electrode), 11 current collecting foil, 12 binder particle group, 13 active material layer, 14 binder film, 101 screen, 102 power supply, 103 printing brush.

Claims

1. A current collecting foil; an active material layer including a plurality of binder particles and a plurality of active material particles; Equipped with the plurality of binder particles are attached to the surface of the current collecting foil and are randomly distributed on the surface of the current collecting foil; The interface resistance between the current collecting foil and the active material layer is 0.004 Ω / cm 2 Below is the electrode.

2. the plurality of binder particles have a smaller D50 than the plurality of active material particles; 10. The electrode of claim 1.

3. The interface resistance is 0.0011 Ω / cm 2 0.0033Ω / cm or more 2 Below is the 3. The electrode according to claim 1 or claim 2.

4. the peel strength between the current collecting foil and the active material layer is 0.6 N / m or more and 3.5 N / m or less; 4. The electrode according to claim 1.

5. The D50 of the plurality of active material particles is 3 μm or more and 10 μm or less.

5. The electrode according to claim 1.

6. The plurality of active material particles are Li(NiCoMn)O 2 containing particles, 6. The electrode according to claim 1.

7. The plurality of active material particles are Li(NiCoAl)O 2 containing particles, 6. The electrode according to claim 1.

8. the plurality of active material particles include graphite particles; 6. The electrode according to claim 1.

9. the plurality of active material particles include graphite particles and silicon oxide particles; 6. The electrode according to claim 1.

10. the plurality of binder particles include PVdF particles; 8. The electrode according to claim 6 or claim 7.

11. the plurality of binder particles include at least one of SBR particles and CMC particles; 10. The electrode according to claim 8 or claim 9.

12. the plurality of binder particles include SBR particles and CMC particles; 10. The electrode according to claim 8 or claim 9.

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