Composite binder composition for all-solid-state batteries, electrode slurry, and method for manufacturing electrodes for all-solid-state batteries using electrode slurry.

Abstract

The composite binder composition for all-solid-state batteries comprises: a first polymer having a repeating structure represented by the following chemical formula 1a or 1b; and a second polymer comprising at least one selected from diene rubbers, polysiloxanes, and combinations thereof: [Chemical Formula 1a] [Chemical Formula 1b]

Description

Invention Field

[0001] This disclosure relates to composite binder compositions for all-solid-state batteries. Background Technology

[0002] The statements in this section are provided only as background information in connection with this disclosure and do not constitute prior art.

[0003] Recent reports of fires and explosions related to lithium-ion batteries using liquid electrolytes have increased interest in battery safety. Consequently, all-solid-state batteries, which use solid electrolytes instead of liquid electrolytes, are gaining attention. All-solid-state batteries also offer advantages in battery performance, such as safety, high energy density, high output, and long lifespan.

[0004] However, due to the dry process used in all-solid-state batteries, their manufacturing process is complex and their price competitiveness is low, thus limiting their marketability. To apply the wet process to all-solid-state batteries, adhesives must be introduced to improve the bonding strength between electrode materials. Specifically, it is desirable that the adhesives used in all-solid-state batteries do not react with the highly reactive solid electrolyte and exhibit excellent bonding strength even when added in small amounts.

[0005] Meanwhile, solid electrolytes used in all-solid-state batteries include oxide-based solid electrolytes and sulfide-based solid electrolytes. Sulfide-based solid electrolytes exhibit higher lithium-ion conductivity and high reactivity with polar compounds. To suppress the reaction of sulfide-based solid electrolytes and to dissolve or disperse them in non-polar processing solvents, all-solid-state batteries using sulfide-based solid electrolytes primarily utilize non-polar binders with low polarity, such as rubber-based polymers and acrylic polymers. However, since non-polar binders do not contain polar functional groups that impart adhesion, the adhesion of the electrode or solid electrolyte layer using these binders is poorer compared to using polar binders. Summary of the Invention

[0006] This disclosure provides an adhesive composition that imparts excellent adhesion without reacting with sulfide-based solid electrolytes.

[0007] This disclosure provides adhesive compositions capable of imparting flexibility to electrodes and / or solid electrolyte layers.

[0008] This disclosure provides, in one form, an adhesive composition for all-solid-state batteries, comprising: a first polymer comprising a repeating structure represented by chemical formula 1a or 1b; and a second polymer comprising at least one selected from diene rubbers, polysiloxanes, and combinations thereof.

[0009] [Chemical Formula 1a]

[0010]

[0011] [Chemical Formula 1b]

[0012]

[0013] In formula 1a, R1 comprises hydrogen, a halogen element, or a C1-4 alkyl group, R2 comprises an unsubstituted C1-4 alkyl group or an ether group in which a portion of the carbon atom of the alkyl group is substituted with oxygen, and m is an integer from 40 to 2,000; in formula 1b, R3 comprises hydrogen, a halogen element, or a C1-4 alkyl group, x is an integer from 0 to 6, and m is an integer from 40 to 2,000.

[0014] Diene rubbers may include at least one selected from 1,4-polybutadiene, 1,2-polybutadiene, cis-1,4-polyisoprene, trans-1,4-polyisoprene, derivatives thereof substituted with C1-3 alkyl groups, and combinations thereof.

[0015] Polysiloxanes may include at least one selected from polydimethylsiloxane, polydiethylsiloxane, polydipropylsiloxane, polyvinylsiloxane, and combinations thereof.

[0016] The adhesive composition may be a mixture of the first polymer and the second polymer.

[0017] The adhesive composition may be a mixture comprising a first polymer of greater than 0 wt% and less than or equal to 50 wt% and a second polymer of greater than or equal to 50 wt% and less than 100 wt%.

[0018] The adhesive composition may be a copolymer of the first polymer and the second polymer.

[0019] The adhesive composition may be a block copolymer of the first polymer and the second polymer.

[0020] The adhesive composition can be obtained by copolymerizing a first polymer of greater than 0 mol% and less than or equal to 50 mol% and a second polymer of greater than or equal to 50 mol% and less than 100 mol%.

[0021] The adhesive composition can be represented by the following chemical formula 2:

[0022] [Chemical Formula 2]

[0023]

[0024] In chemical formula 2, m is an integer from 40 to 2,000, and n is an integer from 1,500 to 15,000.

[0025] The adhesive composition can be represented by the following chemical formula 3:

[0026] [Chemical Formula 3]

[0027]

[0028] In chemical formula 3, m is an integer from 40 to 2,000, and n is an integer from 1,500 to 15,000.

[0029] Another form of this disclosure provides an electrode slurry for all-solid-state batteries, the electrode slurry comprising: a binder solution including the binder composition and solvent described above; an electrode active material; a conductive material; and a solid electrolyte.

[0030] The solvent may include at least one selected from butyrate, toluene, xylene, anisole, hexane, heptane, dibromomethane, dichloroethane, dichlorohexane, ethanol, ethylene glycol ether, and combinations thereof.

[0031] The adhesive solution may include 2.5 wt% to 45 wt% of an adhesive composition and 97.5 wt% to 55 wt% of a solvent.

[0032] The electrode paste may include 0.1 wt% to 10 wt% of a binder solution, 75 wt% to 95 wt% of an electrode active material, 1 wt% to 10 wt% of a conductive material, and 5 wt% to 25 wt% of a solid electrolyte.

[0033] Another aspect of this disclosure provides a method for manufacturing an electrode for an all-solid-state battery, the method comprising: preparing an adhesive solution comprising the above-described adhesive composition and a solvent; and manufacturing an electrode slurry by mixing the adhesive solution, an electrode active material, a conductive material, and a solid electrolyte; and forming an electrode by applying the electrode slurry onto a substrate and subjecting it to heat treatment.

[0034] The applied electrode paste can be heat-treated at temperatures ranging from 100°C to 250°C for 1 minute to 15 hours.

[0035] According to this disclosure, adhesive compositions that can impart excellent adhesion without reacting with sulfide-based solid electrolytes can be obtained.

[0036] Furthermore, according to the present invention, an adhesive composition capable of imparting flexibility to the electrodes and / or solid electrolyte layers can be obtained.

[0037] Other application areas will become apparent from the description provided herein. It should be understood that the description and specific embodiments are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0038] To facilitate understanding of this disclosure, various forms of the disclosure will now be described by way of example with reference to the accompanying drawings, in which:

[0039] Figure 1 The results of X-ray diffraction of the solid electrolyte membrane, the cathode of Example 1, and the cathode of Example 2 are shown.

[0040] Figure 2 The results of Raman spectra of the solid electrolyte membrane, the cathode of Example 1, and the cathode of Example 2 are shown.

[0041] Figure 3 This is a photograph showing the cathode of the all-solid-state battery of Example 1 undergoing a bending test.

[0042] Figure 4 This is a photograph showing the cathode of the all-solid-state battery of Comparative Example 1, which underwent a bending test.

[0043] Figure 5 The results of the 180° peel strength measurement based on displacement are shown for each of the all-solid-state batteries in Example 1, Comparative Example 2 and Comparative Example 3.

[0044] Figure 6 The measurements of the maximum peel strength of the all-solid-state batteries in each of Examples 1, 2, and Comparative Examples 1 to 3 are shown; and

[0045] Figure 7 This is a graph showing the discharge capacitance of the all-solid-state batteries of Example 1, Comparative Example 2 and Comparative Example 3 according to the number of cycles.

[0046] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way. Detailed Implementation

[0047] The following description is exemplary in nature and is not intended to limit this disclosure, its application, or its uses. It should be understood that in all the drawings, corresponding reference numerals denote the same or corresponding parts and features.

[0048] For clarity of this disclosure, the dimensions of the structures are depicted as larger than their actual size. It will be understood that while terms such as “first,” “second,” etc., may be used herein to describe various elements, these elements are not limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, the “first” element discussed below may be referred to as the “second” element. Similarly, the “second” element may also be referred to as the “first” element. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise.

[0049] It will be further understood that, when used in this specification, the terms "comprising," "including," "having," etc., indicate the presence of the stated features, integers, steps, operations, elements, components, or combinations thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof. Additionally, it will be understood that when an element such as a layer, film, region, or sheet is referred to as being "on" another element, it may be directly on the other element, or there may be intermediate elements between them. Similarly, when an element such as a layer, film, region, or sheet is referred to as being "under" another element, it may be directly under the other element, or there may be intermediate elements between them.

[0050] Unless otherwise stated, all figures, values, and / or representations expressing the amounts of components, reaction conditions, polymer compositions, and mixtures used herein should be considered approximate, including various uncertainties inherent in obtaining these measurements. Therefore, all figures, values, and / or representations should be understood to be modified by the term "about" in all cases. Furthermore, unless otherwise stated, when numerical ranges are disclosed in this specification, the range is continuous and includes all values ​​from the minimum to the maximum of the range. Additionally, unless otherwise indicated, when such ranges are integer values, all integers are included, including the minimum to the maximum value.

[0051] This disclosure relates to a binder solution for all-solid-state batteries, an electrode slurry including the binder solution, and a method for manufacturing an electrode for all-solid-state batteries using the electrode slurry.

[0052] As mentioned above, conventional all-solid-state batteries are mainly manufactured through complex dry processes, resulting in low price competitiveness. Meanwhile, in order to apply the cheaper wet process to the manufacturing of all-solid-state batteries, it is important to select a binder composition that does not react with the sulfide-based solid electrolyte, is chemically stable, and possesses excellent adhesive strength.

[0053] Since the adhesive composition for all-solid-state batteries according to this disclosure includes both polar functional groups and rubber-like functional groups, it adheres firmly to the surface of electrode materials, solid electrolytes, etc., and at the same time, the flexibility of the electrode and solid electrolyte layers is also improved.

[0054] Furthermore, the electrode for all-solid-state batteries according to this disclosure includes an adhesive solution with excellent stability and adhesion. Therefore, even when the adhesive is included in the electrode in a minimal amount, the adhesion between the electrode materials is excellent, thereby improving battery performance.

[0055] Furthermore, the all-solid-state battery according to this disclosure enables the replacement of existing dry processes with wet processes using electrode slurry, thereby reducing manufacturing costs and providing battery performance with high energy density and high output.

[0056] The adhesive composition according to the invention may comprise a first polymer having a repeating structure represented by the following chemical formula 1a or 1b, and a second polymer comprising at least one selected from diene rubbers, polysiloxanes, and combinations thereof:

[0057] [Chemical Formula 1a]

[0058]

[0059] [Chemical Formula 1b]

[0060]

[0061] In chemical formula 1a, R1 may include hydrogen, a halogen element or a C1-4 alkyl group, R2 may include an unsubstituted C1-4 alkyl or ether group, wherein a portion of the alkyl carbon atom may be substituted with oxygen, and m may be an integer from 40 to 2,000.

[0062] In chemical formula 1b, R3 may include hydrogen, a halogen element or a C1-4 alkyl group, x may be an integer from 0 to 6 and m may be an integer from 40 to 2,000.

[0063] The first polymer may include ester groups in the side chains of the repeating structure, as shown in Formula 1a, or may include ester groups in the main chain of the repeating structure, as shown in Formula 1b.

[0064] Ester groups can impart excellent adhesion by inducing polar-polar interactions between the adhesive composition and at least one of the electrode active material, solid electrolyte, and conductive material.

[0065] The second polymer is a rubber-based polymer and may include at least one selected from diene rubbers, polysiloxanes, and combinations thereof. The second polymer can increase the flexibility of the electrode and / or the solid electrolyte layer. Ultimately, the binder composition can suppress electrode breakage by dispersing internal stresses in thick electrodes, etc.

[0066] Diene rubbers may include those selected from 1,4-polybutadiene, 1,2-polybutadiene, cis-1,4-polyisoprene, trans-1,4-polyisoprene, derivatives thereof substituted with C1-3 alkyl groups, and combinations thereof. Derivatives may be in the form where at least one carbon atom of the diene rubber, such as 1,4-polybutadiene, is substituted with a C1-3 alkyl group.

[0067] Polysiloxanes may include at least one selected from polydimethylsiloxane, polydiethylsiloxane, polydipropylsiloxane, polyvinylsiloxane, and combinations thereof.

[0068] Because the binder composition has low polarity, it is completely dispersed in nonpolar solvent groups and can suppress chemical reactions between electrode materials in the electrode slurry.

[0069] The adhesive composition may be a mixture of a first polymer and a second polymer. Here, the adhesive composition may include greater than 0 wt% and less than or equal to 50 wt% of the first polymer and greater than or equal to 50 wt% and less than 100 wt% of the second polymer. When the amounts of the first polymer and the second polymer fall within the aforementioned numerical range, the adhesion and flexibility can be increased to the desired level.

[0070] Furthermore, the adhesive composition can be a copolymer in which the first polymer and the second polymer are copolymerized. Preferably, the adhesive composition is a block copolymer of the first polymer and the second polymer. Here, the adhesive composition can be obtained by copolymerizing a first polymer of greater than 0 mol% and less than or equal to 50 mol% and a second polymer of greater than or equal to 50 mol% and less than 100 mol%. When the amounts of the first polymer and the second polymer fall within the above-mentioned numerical range, the adhesion and flexibility can be increased to the desired level.

[0071] The adhesive composition may include at least one selected from the following chemical formulas 2 to 17:

[0072] [Chemical Formula 2]

[0073]

[0074] [Chemical Formula 3]

[0075]

[0076] [Chemical Formula 4]

[0077]

[0078] [Chemical Formula 5]

[0079]

[0080] [Chemical Formula 6]

[0081]

[0082] [Chemical Formula 7]

[0083]

[0084] [Chemical Formula 8]

[0085]

[0086] [Chemical Formula 9]

[0087]

[0088] [Chemical Formula 10]

[0089]

[0090] [Chemical Formula 11]

[0091]

[0092] [Chemical Formula 12]

[0093]

[0094] [Chemical Formula 13]

[0095]

[0096] [Chemical Formula 14]

[0097]

[0098] [Chemical Formula 15]

[0099]

[0100] [Chemical Formula 16]

[0101]

[0102] [Chemical Formula 17]

[0103]

[0104] In chemical formulas 2 to 17, m can be an integer from 40 to 2,000, and n can be an integer from 1,500 to 15,000.

[0105] The electrode paste according to this disclosure may include: an adhesive solution comprising the above-described adhesive composition and a solvent; an electrode active material; a conductive material; and a solid electrolyte.

[0106] The adhesive composition is as described above, and its description will be omitted below.

[0107] The solvent may include at least one selected from butyrate, toluene, xylene, anisole, hexane, heptane, dibromomethane, dichloroethane, dichlorohexane, ethanol, ethylene glycol ether, and combinations thereof.

[0108] The binder solution may include 2.5 wt% to 45 wt% of a binder composition and 97.5 wt% to 55 wt% of a solvent. If the amount of the binder composition is less than 2.5 wt%, it may be difficult to adjust the viscosity of the slurry. On the other hand, if the amount of the binder composition exceeds 45 wt%, the binder composition may not be uniformly dispersed.

[0109] The electrode active material may be a cathode active material or an anode active material.

[0110] The cathode active material is not particularly limited, and examples thereof may include oxide active materials and sulfide active materials.

[0111] The oxide active material may be a rock salt layer-type active material, such as LiCoO2, LiMnO2, LiNiO2, LiVO2, Li 1+x Ni 1 / 3 Co 1 / 3 Mn 1 / 3 O2, etc., a spinel-type active material such as LiMn2O4, Li(Ni 0.5 Mn 1.5 )O4, etc., an inverse spinel-type active material such as LiNiVO4, LiCoVO4, etc., an olivine-type active material such as LiFePO4, LiMnPO4, LiCoPO4, LiNiPO4, etc., a silicon-containing active material such as Li2FeSiO4, Li2MnSiO4, etc., a rock salt layer-type active material in which a part of the transition metal is replaced by another metal such as LiNi 0.8 Co (0.2-x) Al x O2 (0 < x < 0.2), a spinel-type active material in which a part of the transition metal is replaced by another metal such as Li 1+x Mn 2-x-y M y O4 (M is at least one of Al, Mg, Co, Fe, Ni, and Zn, 0 < x + y < 2) or lithium titanate such as Li4Ti5O 12 etc.

[0112] The sulfide active material may be copper chevrel, iron sulfide, cobalt sulfide, nickel sulfide, etc.

[0113] The anode active material is not particularly limited, and examples thereof may include carbon active materials and metal active materials.

[0114] The carbon active material may be graphite, such as mesocarbon microbeads (MCMB), highly oriented pyrolytic graphite (HOPG), etc., or amorphous carbon such as hard carbon and soft carbon.

[0115] The active metal material can be In, Al, Si, Sn, or an alloy containing at least one of these elements.

[0116] The role of conductive materials is to create electron conduction paths within the electrodes. Conductive materials can be sp... 2 Carbon materials such as carbon black, conductive graphite, ethylene black, carbon nanotubes, or graphene.

[0117] The solid electrolyte can be an oxide-based solid electrolyte or a sulfide-based solid electrolyte. Here, a sulfide-based solid electrolyte with high lithium-ion conductivity is preferred.

[0118] Sulfide solid electrolytes can be Li₂S-P₂S₅, Li₂S-P₂S₅-LiI, Li₂S-P₂S₅-LiCl, Li₂S-P₂S₅-LiBr, 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 (where m and n are positive numbers, and Z is any one of Ge, Zn, and Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li x MO y (where x and y are positive numbers, and M is any one of P, Si, Ge, B, Al, Ga, and In), Li 10 GeP2S 12 wait.

[0119] The electrode paste may comprise 0.1 wt% to 10 wt% of a binder solution, 75 wt% to 95 wt% of electrode active material, 1 wt% to 10 wt% of conductive material, and 5 wt% to 25 wt% of solid electrolyte. If the amount of binder solution is less than 0.1 wt%, the bond strength between the electrode active material, conductive material, and solid electrolyte may deteriorate. On the other hand, if the amount of binder solution exceeds 10 wt%, the electrode resistance may increase due to the binder solution, which may worsen the electrochemical performance, and further improvement in bond strength may not be expected.

[0120] According to this disclosure, a method for manufacturing an electrode may include preparing an adhesive solution comprising the above-described adhesive composition and a solvent; manufacturing an electrode slurry by mixing the adhesive solution, an electrode active material, a conductive material, and a solid electrolyte; and forming an electrode by applying the electrode slurry onto a substrate and subjecting it to heat treatment.

[0121] Adhesive solutions can be prepared by dissolving or dispersing an adhesive composition in a solvent.

[0122] The heat treatment of the applied electrode slurry can be carried out at temperatures of 100°C to 250°C, 150°C to 180°C, or 150°C to 160°C for 1 minute to 15 hours. If the heat treatment temperature is higher than 250°C, side reactions may occur within or between the electrode active material, conductive material, and solid electrolyte in the electrode slurry, undesirably causing changes in the material composition.

[0123] This disclosure will be better understood through the following examples, which are merely illustrative and should not be construed as limiting the scope of this disclosure.

[0124] Example 1

[0125] The first polymer used is tert-butyl polyacrylate with a number-average molecular weight of 20,000 g / mol. The second polymer used is 1,4-polybutadiene with a number-average molecular weight of 130,000 g / mol. The first and second polymers are polymerized to obtain an adhesive composition in the form of a block copolymer represented by Formula 2.

[0126] An adhesive solution was prepared by mixing 10 wt% of the adhesive composition with 90 wt% of the butyrate solvent.

[0127] A cathode paste was prepared by mixing 2 wt% binder solution, 74.5 wt% cathode active material, 2 wt% conductive material, and 21.5 wt% solid electrolyte. The cathode active material used here was LiNi, a lithium transition metal oxide. 0.7 Co 0.15 Mn 0.15 O2 is used, the conductive material is carbon black, and the solid electrolyte is Li6PS5Cl, which has a sulfide-germanium sulfide crystal structure and is used as a Li2S-P2S5-LiCl type sulfide solid electrolyte.

[0128] The cathode is manufactured by applying cathode paste to an aluminum current collector and heat-treating it at 150°C for 3 hours.

[0129] On the cathode, a solid electrolyte membrane, an anode, and a cathode current collector are sequentially stacked using a typical process to fabricate an all-solid-state battery. Here, the solid electrolyte membrane used is Li6PS5Cl, a sulfide solid electrolyte with a silver-germanium sulfide crystal structure, and the anode is lithium indium metal. Additionally, nickel foil is applied as the anode current collector.

[0130] Example 2

[0131] The first polymer used is polymethyl methacrylate with a number-average molecular weight of 68,000 g / mol. The second polymer used is 1,2-polybutadiene with a number-average molecular weight of 142,000 g / mol. The first and second polymers are polymerized to obtain an adhesive composition in the form of a block copolymer represented by Formula 3.

[0132] In addition, the all-solid-state battery was manufactured in the same manner as in Example 1.

[0133] Comparative Example 1

[0134] All-solid-state batteries were manufactured in the same manner as in Example 1, except that a polymethyl methacrylate homopolymer with a number-average molecular weight of 160,000 g / mol was used as the binder composition.

[0135] Comparative Example 2

[0136] The all-solid-state battery was manufactured in the same manner as in Example 1, except that a polytert-butyl acrylate homopolymer with a number-average molecular weight of 143,000 g / mol was used as the binder composition.

[0137] Comparative Example 3

[0138] All-solid-state batteries were manufactured in the same manner as in Example 1, except that a 1,4-polybutadiene homopolymer with a number-average molecular weight of 200,000 g / mol was used as the binder composition.

[0139] Test Example 1

[0140] The reactivity of the binder composition with the solid electrolyte was evaluated. The solid electrolytes for the cathodes and solid electrolyte membranes in Examples 1 and 2 were identical; therefore, the X-ray diffraction and Raman spectroscopy results of the solid electrolyte membranes were used as a reference, and the X-ray diffraction and Raman spectroscopy results of the electrodes in Examples 1 and 2 were compared with the reference. The results are shown in… Figure 1 and 2 .

[0141] refer to Figure 1 and 2As can be seen, the peaks of the solid electrolyte contained in the cathodes of Examples 1 and 2 overlap with the peaks of the solid electrolyte membrane. This means that, in the cathodes of Examples 1 and 2, despite the heat treatment during their manufacturing process, no chemical reaction occurred between the binder composition and the solid electrolyte. Therefore, it is concluded that the binder composition according to this disclosure does not react with the solid electrolyte and exists in a stable state.

[0142] Test Example 2

[0143] The lithium-ion conductivity of each of the all-solid-state batteries in Examples 1, 2, and Comparative Examples 1 to 3 was measured. The results are shown in Table 1 below.

[0144] [Table 1]

[0145]

[0146] In addition, bending tests were performed on the all-solid-state batteries of Examples 1, 2, and Comparative Examples 1 to 3. Specifically, bending tests were performed using a mandrel bending machine with a diameter of 7 mm. The results are shown in Table 2 below.

[0147] [Table 2]

[0148]

[0149] Figure 3 This is a photograph showing the cathode of the all-solid-state battery of Example 1 undergoing a bending test. Figure 4 This is a photograph showing the cathode of the all-solid-state battery of Comparative Example 1, which underwent a bending test.

[0150] The results in Tables 1 and 2 clearly show that the all-solid-state batteries of Examples 1 and 2 exhibit the desired lithium-ion conductivity and flexibility. However, Comparative Examples 1 and 2 show low flexibility, and Comparative Example 3 shows low lithium-ion conductivity.

[0151] Test Example 3

[0152] Peel strength tests were performed on the all-solid-state batteries of Examples 1, 2, and Comparative Examples 1 to 3. Specifically, peel strength tests were conducted using a general-purpose testing machine via a 180° peel test method. The results are shown below. Figure 5 and 6 middle.

[0153] Figure 5 The results of the 180° peel strength measurement based on displacement are shown for the all-solid-state batteries of Example 1, Comparative Example 2 and Comparative Example 3. Figure 6 The results of the measurement of the maximum peel strength of the all-solid-state batteries of Examples 1, 2 and Comparative Examples 1 to 3 are shown.

[0154] In Comparative Example 1, the electrode had low flexibility, and therefore broke during the peel strength test, making measurement impossible. In Comparative Example 2, compared to Examples 1 and 2, the electrode had low flexibility, and the adhesive composition lacked elasticity, resulting in poor adhesion. Comparative Example 3 confirmed that, due to the use of a low-polarity butadiene rubber adhesive, the adhesion between the electrode materials was very low.

[0155] In contrast, as demonstrated in Examples 1 and 2, both polar functional groups and rubber-like functional groups are present in the molecular structure, resulting in excellent adhesion strength between the adhesive and the electrode material, as well as excellent electrode flexibility. Furthermore, the adhesion of the electrode is enhanced due to the elasticity of the adhesive composition.

[0156] Test Example 5

[0157] Charge / discharge tests were performed on the all-solid-state batteries of Example 1, Comparative Example 2, and Comparative Example 3. The charge / discharge tests were conducted using a constant current constant voltage (CCCV) method. The results are shown below. Figure 7 middle.

[0158] Figure 7 This is a graph showing the discharge capacity of the all-solid-state batteries of Example 1, Comparative Example 2, and Comparative Example 3 according to the number of cycles. Referring to this graph, it was confirmed in Example 1 that, compared with Comparative Example 2 and Comparative Example 3, the adhesion between the electrode materials in the electrodes remained at a high level before and after charging and discharging due to enhanced adhesion, and the discharge capacity was improved.

[0159] Specifically, as demonstrated in Comparative Example 3, during the increase and decrease of the volume of the electrode material before and after charging and discharging, the adhesion between the electrode material and the adhesive was insufficient, resulting in a significant reduction in the contact between the electrolyte and the active material, thus exhibiting the lowest discharge capacity.

[0160] Although the specific forms of this disclosure have been described with reference to the accompanying drawings, those skilled in the art will understand that this disclosure may be provided in other specific forms without altering its technical spirit or essential characteristics. Therefore, all the foregoing forms should be understood as non-limiting and illustrative in all circumstances.

Claims

1.A binder composition for an all-solid-state battery, the binder composition comprising: a first polymer including a repeating structure represented by the following Chemical Formula 1a: [Chemical Formula 1a] a second polymer including a diene-based rubber, wherein, in Chemical Formula 1a, R1 includes hydrogen, a halogen element, or a C1-4 alkyl group, R2 includes an unsubstituted C1-4 alkyl group or an ether group in which a part of alkyl carbon atoms is substituted with oxygen, and m is an integer of 40 to 2,000, wherein the first polymer and the second polymer are block-copolymerized, and the binder composition is represented by the following Chemical Formula 2 or Chemical Formula 3: [Chemical Formula 2] wherein, in Chemical Formula 2, m is an integer of 40 to 2,000, and n is an integer of 1,500 to 15,000, [Chemical Formula 3] wherein, in Chemical Formula 3, m is an integer of 40 to 2,000, and n is an integer of 1,500 to 15,000. 2.The binder composition of claim 1, wherein the first polymer is copolymerized in more than 0 mol% and less than or equal to 50 mol%, and the second polymer is copolymerized in more than or equal to 50 mol% and less than 100 mol%. 3.An electrode slurry for an all-solid-state battery, the electrode slurry comprising: a binder solution including a binder composition and a solvent; an electrode active material; a conductive material; and a solid electrolyte wherein the binder composition comprises: a first polymer including a repeating structure represented by the following Chemical Formula 1a: [Chemical Formula 1a] and a second polymer including a diene-based rubber, wherein, in Chemical Formula 1a, R1 includes hydrogen, a halogen element, or a C1-4 alkyl group, R2 includes an unsubstituted C1-4 alkyl group or an ether group in which a part of alkyl carbon atoms is substituted with oxygen, and m is an integer of 40 to 2,000, wherein the first polymer and the second polymer are block-copolymerized, and wherein the binder composition is represented by the following Chemical Formula 2 or Chemical Formula 3: [Chemical Formula 2] wherein, in Chemical Formula 2, m is an integer of 40 to 2,000, and n is an integer of 1,500 to 15,000, [Chemical Formula 3] wherein, in Chemical Formula 3, m is an integer of 40 to 2,000, and n is an integer of 1,500 to 15,000. 4.The electrode slurry of claim 3, wherein the solvent includes at least one selected from the group consisting of butyrate, toluene, xylene, anisole, hexane, heptane, dibromomethane, dichloroethane, dichlorohexane, ethanol, glycol ether, and combinations thereof. 5.The electrode slurry of claim 3, wherein the binder solution includes: 2.5 wt% to 45 wt% of the binder composition; and 97.5 wt% to 55 wt% of the solvent. 6.The electrode slurry of claim 3, which includes 0.1 wt% to 10 wt% of the binder solution, 75 wt% to 95 wt% of the electrode active material, 1 wt% to 10 wt% of the conductive material, and 5 wt% to 25 wt% of the solid electrolyte. 7.A method of manufacturing an electrode for an all-solid-state battery, the method comprising the steps of: preparing a binder solution including a binder composition and a solvent; manufacturing an electrode slurry by mixing the binder solution, an electrode active material, a conductive material, and a solid electrolyte; and forming an electrode by applying the electrode slurry to a substrate and performing a heat treatment, wherein the binder composition includes: a first polymer including a repeating structure represented by the following Chemical Formula 1a: [Chemical Formula 1a] and a second polymer including a diene-based rubber, wherein, in Chemical Formula 1a, R1 includes hydrogen, a halogen element, or a C1-4 alkyl group, R2 includes an unsubstituted C1-4 alkyl group or an ether group in which a part of alkyl carbon atoms is substituted with oxygen, and m is an integer of 40 to 2,000, wherein the first polymer and the second polymer are block-copolymerized, and wherein the binder composition is represented by the following Chemical Formula 2 or Chemical 3: [Chemical Formula 2] wherein, in Chemical Formula 2, m is an integer of 40 to 2,000, and n is an integer of 1,500 to 15,000, [Chemical Formula 3] wherein, in Chemical Formula 3, m is an integer of 40 to 2,000, and n is an integer of 1,500 to 15,000. 8.The method of claim 7, wherein the applied electrode slurry is heat-treated at a temperature of 100℃ to 250℃ for 1 minute to 15 hours.

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