Slurry composition for flexible electrode in secondary battery

Abstract

The present invention provides a slurry composition useful for making electrodes for lithium ion batteries. The slurry composition includes a binder, a solvent, an electrode active material, and an additive. The additive can be a compound described by general formula (1). The binder is a copolymer that includes one or more hydrophilic structural units and one or more hydrophobic structural units. The addition of the additive significantly improves the flexibility of the electrode. A method for producing an electrode using the slurry is also disclosed. Furthermore, batteries containing electrodes made using the slurry composition disclosed herein show excellent electrochemical performance.

Description

Technical Field

[0001] This invention relates to the field of batteries. More specifically, this invention relates to electrodes and electrode slurries for lithium-ion batteries. Background Technology

[0002] Over the past few decades, lithium-ion batteries (LIBs) have been widely used in various applications, especially in consumer electronics, due to their excellent energy density, long cycle life, and high discharge capacity. With the rapid development of the electric vehicle (EV) and grid energy storage markets, high-performance and low-cost LIBs are currently one of the most promising options for large-scale energy storage devices.

[0003] Traditionally, lithium-ion battery electrodes are prepared by coating a metal current collector with an organic slurry. This slurry contains electrode active materials, conductive carbon, and a binder in an organic solvent. The binder (most commonly polyvinylidene fluoride (PVDF)) is dissolved in the solvent and provides good electrochemical stability, strong adhesion, and high flexibility to both the electrode material and the current collector, allowing the electrodes to be stacked and wound into a jelly-roll configuration to form a battery. However, PVDF is only soluble in certain organic solvents, such as N-methyl-2-pyrrolidone (NMP), which is flammable and toxic, thus requiring special processing. During the drying process, an NMP recovery system must be installed to recover NMP vapor. This requires a significant investment, resulting in substantial costs during manufacturing. Furthermore, both NMP and PVDF cause environmental damage.

[0004] In view of the above, it is preferable to use cheaper and more environmentally friendly solvents, such as water. However, in general, aqueous solvents present some difficulties in achieving good dispersion of binder and electrode active material particles. Poor dispersibility leads to poor structural stability and flexibility of the resulting electrode, causing problems such as electrode breakage when wound into a wound configuration.

[0005] Some water-based polymer binder formulations have been successfully applied in electrode production, providing electrode slurries with good dispersibility—that is, homogeneous mixtures without phase separation. However, if the electrode coating has a high density, the resulting electrode will still be highly inflexible and brittle. This problem is most pronounced when using electrode active materials with relatively low energy density, as more material is required to achieve the same output capacity, resulting in thicker and less flexible electrodes.

[0006] When an electrode lacking flexibility is bent, the stress concentrated at the bend causes the electrode to peel off and break, thereby damaging the electrode structure. This significantly reduces the performance and lifespan of the secondary battery.

[0007] US Patent Application Publication No. US2020 / 0029177A1 discloses a lithium secondary battery cathode, wherein the cathode active material layer comprises a cathode active material, a binder, graphene, and carbon black. Specifically, the density of the cathode active material layer should be greater than or equal to 4.3 g / cm³. 3 The tested cathode active material was LiCoO2. The patent application discloses that a cathode with these characteristics will not break when wound, and batteries containing this cathode exhibit higher stability and cycle life. However, this prior art has only successfully demonstrated these benefits when the binder is PVDF dissolved in NMP. Furthermore, the use of two carbon materials is essential, and graphene cannot be replaced with the more common form of graphite, thus significantly increasing costs.

[0008] Therefore, there is an urgent need to invent a method to improve the flexibility of electrodes produced by water-based processes. Summary of the Invention

[0009] The aforementioned needs are met through the various aspects and embodiments disclosed herein. In one aspect, this document provides a slurry for preparing secondary battery electrodes, the slurry comprising electrode active materials, binders, additives, and solvents.

[0010] On the other hand, this document provides an electrode for a secondary battery, comprising a current collector and an electrode layer coated on one or more surfaces of the current collector, wherein the electrode layer comprises the aforementioned electrode slurry. In some embodiments, the electrode layer comprises an electrode active material, a binder, and additives.

[0011] In another aspect, this article provides a method for preparing the above-mentioned electrode paste.

[0012] The additives are designed to provide flexibility to the resulting electrodes. In particular, the addition of additives significantly improves electrode flexibility when the solvent is water or an aqueous solution and an aqueous binder is used. Furthermore, improved electrochemical performance has been observed in cylindrical secondary batteries containing electrodes produced using the additives. Attached Figure Description

[0013] Figure 1 A flowchart showing the electrode preparation steps according to one embodiment of the present invention is shown.

[0014] Figure 2 This image shows the coating on the electrode according to Embodiment 1 of the present invention.

[0015] Figure 3 This image shows the coating on the electrode of Comparative Example 4 of the present invention. Detailed Implementation

[0016] On one hand, this document provides a slurry for preparing a secondary battery electrode, the slurry comprising an electrode active material, a binder, additives, and a solvent. On the other hand, this document provides an electrode for a secondary battery comprising a current collector and an electrode layer coated on one or more surfaces of the current collector, wherein the electrode layer comprises the aforementioned electrode slurry. In yet another aspect, this document provides a method for preparing the aforementioned electrode slurry.

[0017] The term "electrode" refers to either "cathode" or "anode".

[0018] The terms "positive electrode" and "cathode" are used interchangeably. Similarly, the terms "negative electrode" and "anode" are used interchangeably.

[0019] The term "binder" or "binder material" refers to a chemical compound, mixture of compounds, or polymer used to fix electrode active materials and / or conductive agents in place and adhere them to a conductive substrate to form an electrode. In some embodiments, the electrode does not contain any conductive agent. In some embodiments, the binder forms a colloid, solution, or dispersion in an aqueous solvent such as water.

[0020] The term "binder composition" refers to a colloid, dispersion, or solution comprising a binder and a dispersion medium or solvent. In some embodiments, the dispersion medium or solvent is water.

[0021] The term "polymer" refers to a polymeric compound prepared by means of polymerizing monomers, regardless of whether the monomers are of the same or different types. The general term "polymer" includes the terms "homogeneous polymer" and "copolymer".

[0022] The term "homopolymer" refers to a polymer prepared by polymerizing monomers of the same type. The term "copolymer" refers to a polymer prepared by polymerizing at least two monomers of different types.

[0023] The term "total weight of repeating units" refers to the total weight obtained after repeating the repeating units.

[0024] The term "monomer unit" refers to the building block that contributes to the structure of a polymer by a single monomer.

[0025] The term "structural unit" refers to the total monomer unit contributed by the same monomer type in the polymer.

[0026] The term "olefin" refers to an unsaturated hydrocarbon compound having at least one carbon-carbon double bond.

[0027] The term "hydrophilic" refers to a tendency to interact strongly with polar solvents (especially water) or polar functional groups, such as through the formation of hydrogen bonds. Hydrophilic groups themselves are usually polar, and many compounds containing hydrophilic groups are soluble in water. Some non-limiting examples of hydrophilic groups include carboxylic acids, hydroxyl groups, and amides.

[0028] The term "hydrophobic group" refers to a functional group that does not tend to interact strongly with polar solvents (especially water) or polar functional groups, such as by forming hydrogen bonds. Hydrophobic groups are generally nonpolar, and compounds containing hydrophobic groups are usually insoluble in water.

[0029] The term "number-average molecular weight" for polymers. n In mathematics, it is defined as:

[0030]

[0031] Where N i It has a specific molecular weight M i The number of polymer molecules.

[0032] The term "weight-average molecular weight" of polymers (A) w In mathematics, it is defined as:

[0033]

[0034] Where N i It has a specific molecular weight M i The number of polymer molecules.

[0035] The "hydrophile-lipophile balance number" (HLB) of a chemical substance is mathematically defined as:

[0036]

[0037] Where M h HLB is the molecular weight of the hydrophilic portion of a chemical substance, while M is the total molecular weight of the chemical substance. The higher the HLB value, the stronger the hydrophilicity of the chemical substance.

[0038] The term "conductive agent" refers to a material with good electrical conductivity. Therefore, conductive agents are typically mixed with electrode active materials during electrode formation to improve the electrode's conductivity. In some embodiments, the conductive agent is chemically active. In some embodiments, the conductive agent is chemically inert.

[0039] The term "homogenizer" refers to a device that can be used to homogenize materials. The term "homogenization" refers to a process of uniformly distributing materials throughout a fluid. Any conventional homogenizer can be used in the methods disclosed herein. Some non-limiting examples of homogenizers include stirred mixers, planetary mixers, agitators, and ultrasonic generators.

[0040] The term "planetary mixer" refers to a device used to mix or agitate different materials to produce a homogeneous mixture, which consists of paddles undergoing planetary motion within a container. In some embodiments, the planetary mixer includes at least one planetary paddle and at least one high-speed dispersing paddle. The planetary paddle and the high-speed dispersing paddle rotate along their respective axes and also continuously along the container. Rotational speed can be expressed in revolutions per minute (rpm), which refers to the number of revolutions completed by the rotating body in one minute.

[0041] The term "ultrasonic generator" refers to a device capable of using ultrasonic energy to agitate particles in a sample. Any ultrasonic generator capable of dispersing the slurry disclosed herein may be used. Some non-limiting examples of ultrasonic generators include ultrasonic baths, probe-type ultrasonic generators, and ultrasonic flow cells.

[0042] The term "ultrasonic bath" refers to a device that transmits ultrasonic energy to a liquid sample through the walls of an ultrasonic bath container.

[0043] The term "probe-type ultrasonic generator" refers to an ultrasonic probe immersed in a medium for direct ultrasonic processing. The term "direct ultrasonic processing" refers to ultrasonic waves being directly coupled into the processing liquid.

[0044] The terms "ultrasonic flow cell" or "ultrasonic reactor chamber" refer to a device that can perform ultrasonic treatment in a flow mode. In some embodiments, the ultrasonic flow cell is a single-pass configuration, a multi-pass configuration, or a circulating configuration.

[0045] The term "apply" refers to the action of laying or spreading a substance on a surface.

[0046] The term "current collector" refers to any conductive substrate in contact with the electrode layer that is capable of conducting current flowing to the electrodes during the discharge or charging of a secondary battery. Some non-limiting examples of current collectors include a single conductive metal layer or substrate, and a single conductive metal layer or substrate covered with a conductive coating (e.g., a carbon black-based coating). The conductive metal layer or substrate can be in the form of a foil or a porous body with a three-dimensional network structure, and can be a polymer or a metallic material or a metallized polymer. In some embodiments, the three-dimensional porous current collector is covered with a conformal carbon layer.

[0047] The term "electrode layer" refers to a layer that is in contact with the current collector and contains electrochemically active material. In some embodiments, the electrode layer is formed by applying a coating to the current collector. In some embodiments, the electrode layer is located on one or both sides of the current collector. In other embodiments, a three-dimensional porous current collector is covered with a conformal electrode layer.

[0048] The term "room temperature" refers to an indoor temperature of approximately 18°C ​​to approximately 30°C, such as 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30°C. In some embodiments, room temperature refers to a temperature of approximately 20°C + / - 1°C, + / - 2°C, or + / - 3°C. In other embodiments, room temperature refers to a temperature of approximately 22°C or approximately 25°C.

[0049] The term "particle size D50" refers to the cumulative 50% size (D50) based on volume, which is the particle size at the 50% point on the cumulative curve when plotting the cumulative curve (i.e., the particle diameter at the 50th percentile (median) of the particle volume), such that the particle size distribution is obtained based on volume and the total volume is 100%. Further, with respect to the electrode active material of the present invention, particle size D50 refers to the volume average particle size of secondary particles formed by the aggregation of primary particles, while in the case where the particles consist only of primary particles, particle size D50 refers to the volume average particle size of the primary particles.

[0050] The term "solid content" refers to the amount of non-volatile substances remaining after evaporation.

[0051] The term "peel strength" refers to the force required to separate two bonded materials (such as current collector and electrode layers). It is a measure of the bond strength between the two materials and is typically expressed in N / cm.

[0052] The term "C-rate" refers to the charging or discharging rate of a battery, expressed in ampere-hours (Ah) or milliampere-hours (mAh), based on its total storage capacity. For example, a 1C rate means utilizing all the stored energy in one hour; 0.1C means utilizing 10% of the energy in one hour or all the energy in 10 hours; and 5C means utilizing all the energy in 12 minutes.

[0053] The term "ampere-hour (Ah)" is a unit used to describe the storage capacity of a battery. For example, a 1Ah battery can provide 1 ampere of current for one hour, or 0.5 amperes of current for two hours, and so on. Therefore, 1 ampere-hour (Ah) is equivalent to 3,600 coulombs of charge. Similarly, the term "milliampere-hour (mAh)" is also a unit of battery storage capacity, and is 1 / 1,000th of an ampere-hour.

[0054] The term "battery cycle life" refers to the number of complete charge-discharge cycles a battery can complete before its rated capacity drops below 80% of its initial rated capacity.

[0055] The term "capacity" is a characteristic of an electrochemical battery that refers to the total amount of charge that the battery (e.g., a 4x4 battery) can hold. Capacity is usually expressed in ampere-hours (Ah-hours). The term "specific capacity" refers to the output capacity of an electrochemical battery (e.g., a 4x4 battery) per unit weight, usually expressed in Ah / kg or mAh / g.

[0056] In the following description, all numerical values ​​disclosed herein are approximate, whether or not they are used in conjunction with the terms "approximately" or "approximately". They can vary by 1%, 2%, 5%, or sometimes 10% to 20%. Whenever a lower bound R is disclosed... L and upper limit R U When the numerical range is specified, any value within that range is specifically disclosed. Specifically, the following values ​​within that range are specifically disclosed: R = R L +k*(R U -R L ), where k is a variable from 0% to 100%. Furthermore, any numerical range defined by the two R values ​​above is also specifically disclosed.

[0057] In this specification, all descriptions of singular cases also include plural cases, and vice versa.

[0058] On one hand, the present invention provides a slurry for preparing electrodes for secondary batteries, the slurry comprising electrode active materials, binders, additives, and solvents. Electrodes made from the electrode slurry disclosed herein exhibit significantly improved flexibility and remain smooth and wrinkle-free even at high surface and high compaction densities. The electrochemical performance of batteries incorporating such electrodes is also improved.

[0059] Additives embed themselves between the polymer chains of the binder and increase the distance between the chains, making the electrodes softer and more flexible. This, in turn, increases the fluidity of molecules within the polymer chains. By increasing the distance between the polymer chains in the binder, the intermolecular forces between the polymer chains within the binder are also reduced. Furthermore, additive molecules can also interact electrostatically with the polymer chains themselves, further reducing the effective intermolecular forces between the polymer chains through the additional effect of these interactions. The overall result is increased flexibility of the binder. This effect is particularly pronounced in water-based binders because they contain hydrophilic groups that, through the formation of hydrogen bonds and other polar interactions, create strong interactions between the polymer chains of the binder.

[0060] In some embodiments, the additive is a polymer represented by the following general formula (1):

[0061]

[0062] The additive represented by general formula (1) contains three repeating units α, β, and γ, which are repeated a, b, and c, respectively. In some embodiments, the values ​​of a and c are the same. In other embodiments, the values ​​of a and c are different.

[0063] In some embodiments, a and c in general formula (1) are each independently about 2 to about 40, about 5 to about 40, about 2 to about 30, about 5 to about 30, about 2 to about 25, about 3 to about 25, about 5 to about 25, about 2 to about 20, about 3 to about 20, about 5 to about 20, about 2 to about 15, about 3 to about 15, about 2 to about 12, about 3 to about 12, about 2 to about 10, or about 3 to about 10. In some embodiments, a and c in general formula (1) are each independently 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12.

[0064] In some embodiments, a and c in general formula (1) are each independently about 40 or less, about 35 or less, about 30 or less, about 25 or less, about 20 or less, about 15 or less, about 12 or less, or about 10 or less. In some embodiments, a and c in general formula (1) are each independently about 2 or more, about 3 or more, about 5 or more, about 10 or more, about 15 or more, about 20 or more, or about 25 or more.

[0065] In some embodiments, b in general formula (1) is about 10 to about 50, about 25 to about 50, about 10 to about 40, about 12 to about 40, about 15 to about 40, about 17 to about 40, about 20 to about 40, about 25 to about 40, about 10 to about 35, about 12 to about 35, about 15 to about 35, about 17 to about 35, about 20 to about 35, about 10 to about 32, about 12 to about 32, about 15 to about 32, about 17 to about 32, about 10 to about 30, about 12 to about 30, about 15 to about 30, or about 17 to about 30. In some embodiments, b in general formula (1) is 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40.

[0066] In some embodiments, b in general formula (1) is about 50 or less, about 40 or less, about 35 or less, about 32 or less, about 30 or less, or about 25 or less. In some embodiments, b in general formula (1) is about 10 or greater, about 12 or greater, about 15 or greater, about 17 or greater, about 20 or greater, or about 25 or greater.

[0067] In some embodiments, the value of b in general formula (1) is less than or equal to the value of a or c in general formula (1). In other embodiments, the value of b in general formula (1) is greater than or equal to the value of a or c in general formula (1). In some embodiments, the value of b in general formula (1) is less than or equal to the sum of a and c in general formula (1). In other embodiments, the value of b in general formula (1) is greater than or equal to the sum of a and c in general formula (1).

[0068] In some embodiments, the hydrophilic-lipophilic balance value of the additive represented by general formula (1) is about 3 to about 13, about 3.5 to about 13, about 4 to about 13, about 4.5 to about 13, about 5 to about 13, about 5.5 to about 13, about 6 to about 13, about 6.5 to about 13, about 7 to about 13, about 7.5 to about 13, about 7.5 to about 12.5, about 7.5 to about 12, about 7.5 to about 11.5, about 7.5 to about 11, about 7.5 to about 10.5, about 7.5 to about 10, about 7.5 to about 9.5, about 7.5 to about 9, or about 7.5 to about 8.5.

[0069] In some embodiments, the hydrophilic-lipophilic balance value of the additive represented by general formula (1) is about 13 or less, about 12.5 or less, about 12 or less, about 11.5 or less, about 11 or less, about 10.5 or less, about 10 or less, about 9.5 or less, about 9 or less, or about 8.5 or less. In some embodiments, the hydrophilic-lipophilic balance value of the additive represented by general formula (1) is about 3 or more, about 3.5 or more, about 4 or more, about 4.5 or more, about 5 or more, about 5.5 or more, about 6 or more, about 6.5 or more, about 7 or more, or about 7.5 or more.

[0070] In some embodiments, the number-average molecular weight or weight-average molecular weight of the additive represented by general formula (1) is about 1,000 to about 5,000, about 2,000 to about 5,000, about 3,000 to about 5,000, about 1,000 to about 4,500, about 1,500 to about 4,500, about 2,000 to about 4,500, about 2,500 to about 4,500, about 3,000 to about 4,500, about 1,000 to about 4,000, about 1,500 to about 4,000, about 2,000 to about 4,000, about 2,5 ... 00 to about 4,000, about 1,000 to about 3,000, about 1,200 to about 3,000, about 1,500 to about 3,000, about 1,800 to about 3,000, about 2,000 to about 3,000, about 1,000 to about 2,800, about 1,200 to about 2,800, about 1,500 to about 2,800, about 1,800 to about 2,800, about 2,000 to about 2,800, about 1,000 to about 2,500, about 1,200 to about 2,500 or about 1,500 to about 2,500.

[0071] In some embodiments, the number-average molecular weight or weight-average molecular weight of the additive represented by general formula (1) is about 5,000 or less, about 4,000 or less, about 3,500 or less, about 3,000 or less, about 2,800 or less, about 2,500 or less, about 2,200 or less, or about 2,000 or less. In some embodiments, the number-average molecular weight or weight-average molecular weight of the additive represented by general formula (1) is about 1,000 or greater, about 1,200 or greater, about 1,500 or greater, about 1,800 or greater, about 2,000 or greater, about 2,200 or greater, about 2,500 or greater, about 2,800 or greater, about 3,000 or greater, about 3,200 or greater, or about 3,500 or greater.

[0072] In some embodiments, based on the number-average molecular weight or weight-average molecular weight of the additives, the proportion of the total weight of α and γ is independently, by weight, about 1% to about 40%, about 5% to about 40%, about 10% to about 40%, about 15% to about 40%, about 20% to about 40%, about 1% to about 35%, about 5% to about 35%, about 10% to about 35%, about 15% to about 35%, about 20% to about 35%, about 1% to about 30%, about 5% to about 30%, about 10% to about 30%, about 15% to about 30%, about 1% to about 25%, about 5% to about 25%, about 10% to about 25%, about 1% to about 20%, or 5% to about 20%.

[0073] In some embodiments, the percentage of the total weight of α and γ, based on the number-average molecular weight or weight-average molecular weight of the additives, is independently about 40% or less, about 35% or less, about 30% or less, about 25% or less, about 20% or less, or about 15% or less by weight. In some embodiments, the percentage of the total weight of α and γ, based on the number-average molecular weight or weight-average molecular weight of the additives, is independently about 1% or more, about 5% or more, about 10% or more, about 15% or more, or about 20% or more by weight.

[0074] In some embodiments, based on the number-average molecular weight or weight-average molecular weight of the additives, the proportion of the total weight of β is approximately 50% to 99%, approximately 55% to 99%, approximately 60% to 99%, approximately 65% ​​to 99%, approximately 70% to 99%, approximately 75% to 99%, approximately 50% to 95%, approximately 55% to 95%, approximately 60% to 95%, approximately 65% ​​to 95%, and approximately 50% by weight. The percentage of total weight of β is approximately 90%, approximately 55%, approximately 60%, approximately 65%, approximately 70%, approximately 50%, approximately 85%, approximately 55%, approximately 60%, approximately 65%, approximately 65%, approximately 70%, approximately 50%, approximately 55%, approximately 60%, approximately 70%, approximately 50%, approximately 55%, approximately 60%, approximately 75%, or approximately 55% to 90%. In some embodiments, the percentage of total weight of β is approximately 99%, approximately 95%, approximately 90%, approximately 85%, approximately 80%, approximately 75%, or approximately 70% or less by weight, based on the number-average molecular weight or weight-average molecular weight of the additives. In some embodiments, the percentage of the total weight of β based on the number-average molecular weight or weight-average molecular weight of the additive is about 50% or more, about 55% or more, about 60% or more, about 65% or more, about 70% or more, or about 75% or more by weight.

[0075] In some embodiments, based on the number-average molecular weight or weight-average molecular weight of the additives, the proportion of the total weight of β is less than or equal to the proportion of the total weight of α or γ. In other embodiments, based on the number-average molecular weight or weight-average molecular weight of the additives, the proportion of the total weight of β is greater than or equal to the proportion of the total weight of α or γ. In some embodiments, based on the number-average molecular weight or weight-average molecular weight of the additives, the proportion of the total weight of β is less than or equal to the proportion of the sum of the total weights of α and γ. In other embodiments, based on the number-average molecular weight or weight-average molecular weight of the additives, the proportion of the total weight of β is greater than or equal to the proportion of the sum of the total weights of α and γ.

[0076] Controlling the total weight proportion of α, β, and γ in the molecule of the additive represented by general formula (1) is particularly critical. For example, a low proportion of α and / or γ may result in poor additive performance due to insufficient interaction with the binder, thus preventing the additive from reducing the interactions between polymer chains of the binder. Conversely, an excessively high proportion of α and / or γ can also lead to reduced additive performance because the likelihood of repeating units α and / or γ in the same additive molecule interacting (“bridging”) with different polymer chains of the binder increases, resulting in an increase in the net interaction between different polymer chains of the binder, rather than a desired reduction.

[0077] Similarly, controlling the average molecular weight of the additive represented by general formula (1) is also crucial. A low average molecular weight may result in poor additive performance due to insufficient interaction with the binder. Conversely, an excessively high average molecular weight may lead to decreased additive performance due to an increased likelihood of bridging.

[0078] In some embodiments, based on the total weight of solids in the electrode slurry, the proportion of additives in the electrode slurry is approximately 0.1% to about 5% by weight, approximately 0.2% to about 5%, approximately 0.5% to about 5%, approximately 0.8% to about 5%, approximately 1% to about 5%, approximately 1.2% to about 5%, approximately 1.5% to about 5%, approximately 1.8% to about 5%, approximately 2% to about 5%, approximately 2.2% to about 5%, approximately 2.5% to about 5%, approximately 0.1% to about 4.5%, approximately 0.2% to about 4.5%, approximately 0.5% to about 4.5%, approximately 0.8% to about 4.5%, approximately 1% to about 4.5%, approximately 1.2% to about 4.5%, approximately 1.5% to about 4.5%, approximately 1.8% to about 4.5%, and approximately 2% to about 4%. 5%, about 0.1% to about 4%, about 0.2% to about 4%, about 0.2% to about 4%, about 0.5% to about 4%, about 0.8% to about 4%, about 1% to about 4%, about 1.2% to about 4%, about 1.5% to about 4%, about 1.8% to about 4%, about 2% to about 4%, about 0.1% to about 3.5%, about 0.2% to about 3.5%, about 0.5% to about 3.5%, about 0.8% to about 3.5%, about 1% to about 3.5%, about 1.2% to about 3.5%, about 1.5% to about 3.5%, about 0.1% to about 3%, about 0.2% to about 3%, about 0.5% to about 3%, about 0.8% to about 3%, about 1% to about 3%, about 0.5% to about 2%, or about 0.5% to about 1.5%.

[0079] In some embodiments, the proportion of additives in the electrode slurry, based on the total weight of solids in the slurry, is about 5% or less, about 4.5% or less, about 4% or less, about 3.5% or less, or about 3% or less by weight. In some embodiments, the proportion of additives in the electrode slurry, based on the total weight of solids in the slurry, is about 0.1% or more, about 0.2% or more, about 0.3% or more, about 0.4% or more, about 0.5% or more, about 0.6% or more, about 0.7% or more, about 0.8% or more, about 0.9% or more, about 1% or more, about 1.1% or more, about 1.2% or more, about 1.3% or more, about 1.4% or more, or about 1.5% or more by weight.

[0080] In some embodiments, more than one additive may be used in the electrode paste. In other embodiments, the electrode paste contains only one additive.

[0081] In some embodiments, the binder comprises a copolymer. In some embodiments, the copolymer comprises one or more hydrophilic structural units and one or more hydrophobic structural units.

[0082] In some embodiments, the one or more hydrophilic structural units are derived from a carboxylic acid-containing monomer. In some embodiments, the carboxylic acid-containing monomer is selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, 2-butylcrotonic acid, cinnamic acid, maleic acid, fumaric acid, itaconic acid, 4,4-dimethylitaconic acid, angelic acid, tiglic acid, 2-pentenoic acid, 2-hexenoic acid, 2-heptenoic acid, 2-octenic acid, 2-nonenoic acid, 2-decenoic acid, their isomers, and combinations thereof.

[0083] The carboxylic acid-containing monomer may optionally be substituted with one or more substituents. In some embodiments, the one or more substituents are selected from the group consisting of C1-C6 alkyl, C1-C6 alkoxy, hydroxy, halogen, phenyl, amino, carbonyl, and combinations thereof. Some non-limiting examples of substituted carboxylic acid-containing monomers include 2-ethylacrylic acid, 3,3-dimethylacrylic acid, 3-propylacrylic acid, 2-methyl-3-ethylacrylic acid, 3-isopropylacrylic acid, 3-methyl-3-ethylacrylic acid, 2-isopropylacrylic acid, trimethacrylic acid, 2-methyl-3,3-diethylacrylic acid, 3-butylacrylic acid, 2-butylacrylic acid, 2-pentylacrylic acid, α-acetoxyacrylic acid, β-trans-aryloxyacrylic acid, α-chloro-β-(E)-methoxyacrylic acid, and combinations thereof.

[0084] In some embodiments, the carboxylic acid-containing monomer is selected from the group consisting of methylmaleic acid, dimethylmaleic acid, phenylmaleic acid, bromomaleic acid, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, difluoromaleic acid, nonylhydrogen maleate, decyl hydrogen maleate, dodecyl hydrogen maleate, octadecyl hydrogen maleate, fluoroalkyl hydrogen maleate, or combinations thereof. In some embodiments, the one or more hydrophilic structural units are not derived from the carboxylic acid-containing monomer.

[0085] In some embodiments, the carboxylic acid-containing monomer exists in the form of a carboxylic acid, a carboxylate, a carboxylic acid derivative, or a combination thereof. In some embodiments, the carboxylate and carboxylic acid derivative may be salts or derivatives of the carboxylic acids listed above. In some embodiments, the carboxylic acid derivative is selected from the group consisting of maleic anhydride, methylmaleic anhydride, dimethylmaleic anhydride, acrylic anhydride, methacrylic anhydride, methacrolein, methacryloyl chloride, methacryloyl fluoride, methacryloyl bromide, and combinations thereof. In some embodiments, the carboxylic acid-containing monomer does not exist in the form of a carboxylate or a carboxylic acid derivative.

[0086] In some embodiments, the carboxylate comprises a metal cation. In some embodiments, the metal cation is selected from the group consisting of Li, Na, K, Mg, Ca, Al, Fe, Zn, Cu, and combinations thereof. In some embodiments, the carboxylate does not comprise a metal cation. In some embodiments, the carboxylate comprises an ammonium cation.

[0087] In some embodiments, the one or more hydrophilic structural units are derived from hydroxyl-containing monomers. In some embodiments, the hydroxyl-containing monomer is a compound containing a hydroxyl group and either an acrylate or a methacrylate. In some embodiments, the hydroxyl-containing monomer is selected from the group consisting of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl acrylate, 6-hydroxyhexyl methacrylate, 1,4-cyclohexanediethanol monomethacrylate, 1,4-cyclohexanediethanol monomethacrylate, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monomethacrylate, diethylene glycol monomethacrylate, and combinations thereof. In some embodiments, the hydroxyl-containing monomer is an alcohol. In some embodiments, the hydroxyl-containing monomer is selected from the group consisting of vinyl alcohol, allyl alcohol, crotonol, its isomers, and combinations thereof. In some embodiments, the one or more hydrophilic structural units are not derived from hydroxyl-containing monomers.

[0088] In some embodiments, the one or more hydrophilic structural units are derived from an amide-containing monomer. In some embodiments, the amide-containing monomer is selected from acrylamide, methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-n-propylmethacrylamide, N-isopropylmethacrylamide, isopropylacrylamide, N-n-butylmethacrylamide, N-isobutylmethacrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N-hydroxymethylmethacrylamide, N-(methoxymethyl)methacrylamide, N-(ethoxymethyl)methacrylamide, N- The group consisting of (propoxymethyl)methacrylamide, N-(butoxymethyl)methacrylamide, N,N-dimethylmethacrylamide, N-(3-(dimethylamino)propyl)methacrylamide, N-(2-(dimethylamino)ethyl)methacrylamide, N,N-(dihydroxymethyl)methacrylamide, diacetone methacrylamide, diacetone acrylamide, methacryloylmorpholine, N-(hydroxy)methacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N,N'-methylenebisacrylamide, N-hydroxymethylacrylamide, its isomers and combinations thereof.

[0089] The amide-containing monomer may optionally be substituted with one or more substituents. In some embodiments, the one or more substituents are selected from the group consisting of C1-C6 alkyl, C1-C6 alkoxy, hydroxyl, halogroup, phenyl, amino, carbonyl, and combinations thereof. In some embodiments, the one or more hydrophilic structural units are not derived from the amide-containing monomer.

[0090] In some embodiments, the one or more hydrophobic structural units are derived from nitrile-containing monomers. In some embodiments, the nitrile-containing monomers comprise α,β-olefinically unsaturated nitrile monomers. In some embodiments, the nitrile-containing monomers are selected from the group consisting of acrylonitrile, α-haloacrylonitrile, α-alkylacrylonitrile, and combinations thereof. In some embodiments, the nitrile-containing monomers are selected from the group consisting of α-chloroacrylonitrile, α-bromoacrylonitrile, α-fluoroacrylonitrile, methacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile, α-n-hexylacrylonitrile, α-methoxyacrylonitrile, 3-methoxyacrylonitrile, 3-ethoxyacrylonitrile, α-acetoxyacrylonitrile, α-phenylacrylonitrile, α-tolylacrylonitrile, α-(methoxyphenyl)acrylonitrile, α-(chlorophenyl)acrylonitrile, α-(cyanophenyl)acrylonitrile, vinylidene cyanide, its isomers, and combinations thereof.

[0091] The nitrile-containing monomer may optionally be substituted with one or more substituents. In some embodiments, the one or more substituents are selected from the group consisting of C1-C6 alkyl, C1-C6 alkoxy, hydroxyl, halogroup, phenyl, amino, carbonyl, and combinations thereof. In some embodiments, the one or more hydrophobic structural units are not derived from the nitrile-containing monomer.

[0092] In other embodiments, the one or more hydrophobic structural units are derived from olefin monomers. In some embodiments, the olefin is selected from the group consisting of styrene, ethylene, propylene, isobutene, butene, pentene, hexene, hepten, octene, nonene, decene, dodecene, tetradecene, hexadecene, octadecene, eicosene, isomers thereof, and combinations thereof. In some embodiments, the olefin is selected from the group consisting of 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 4,6-dimethyl-1-heptene, 4-vinylcyclohexene, vinylcyclohexane, norbornadiene, ethylidene norbornene, cyclopentene, cyclohexene, dicyclopentadiene, cyclooctene, and combinations thereof. In some embodiments, the olefin is propylene, butene, pentene, hexene, octene, or combinations thereof.

[0093] In some embodiments, the olefin is a conjugated diene. In some embodiments, the conjugated diene is C4-C. 40 Dienes. In some embodiments, the conjugated diene is an aliphatic conjugated diene. In some embodiments, the aliphatic conjugated diene is selected from the group consisting of 1,3-butadiene, 1,3-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, isoprene, myrcene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, substituted linear conjugated pentadienes, substituted branched conjugated hexadienes, and combinations thereof.

[0094] The olefin monomer may optionally be substituted with one or more substituents. In some embodiments, the one or more substituents are selected from the group consisting of C1-C6 alkyl, C1-C6 alkoxy, hydroxyl, halogroup, phenyl, amino, carbonyl, and combinations thereof. In other embodiments, the one or more hydrophobic structural units are not derived from the olefin monomer.

[0095] In other embodiments, the one or more hydrophobic structural units are derived from monomers containing aromatic vinyl groups. In some embodiments, the monomers containing aromatic vinyl groups are selected from the group consisting of styrene, α-methylstyrene, vinyltoluene, divinylbenzene, and combinations thereof. In other embodiments, the one or more hydrophobic structural units are not derived from monomers containing aromatic vinyl groups.

[0096] In other embodiments, the one or more hydrophobic structural units are derived from ester-containing monomers. In some embodiments, the ester-containing monomers are C1-C. 20 Alkyl acrylate, C1-C 20 Alkyl methacrylates, cycloalkyl acrylates, or combinations thereof. In some embodiments, the ester-containing monomer is selected from the group consisting of methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 3,3,5-trimethylhexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, lauryl acrylate, n-tetradecyl acrylate, octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, methoxymethyl acrylate, methoxyethyl acrylate, ethoxymethyl acrylate, ethoxyethyl acrylate, perfluorooctyl acrylate, stearate acrylate, and combinations thereof. In some embodiments, the ester-containing monomer is cyclohexyl acrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, 3,3,5-trimethylcyclohexyl acrylate, or combinations thereof. In some embodiments, the ester-containing monomer is selected from the group consisting of methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, isobutyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, lauryl methacrylate, n-tetradecyl methacrylate, stearate methacrylate, 2,2,2-trifluoroethyl methacrylate, phenyl methacrylate, benzyl methacrylate, and combinations thereof. In other embodiments, the one or more hydrophobic structural units are not derived from the ester-containing monomer.

[0097] In some embodiments, the adhesive may contain structural units derived from monomers having one or more functional groups comprising halogens, O, N, S, or combinations thereof. Some non-limiting examples of said functional groups include alkoxy, aryloxy, nitro, mercapto, thioether, imine, cyano, amide, amino (primary, secondary, or tertiary amine), carboxyl, ketone, aldehyde, ester, hydroxyl, and combinations thereof. In some embodiments, the functional group itself is or comprises alkoxy, aryloxy, carboxyl (i.e., -COOH), nitrile, -COOCH3, -CONH2, -OCH2CONH2, or -NH2. In some embodiments, the adhesive material may contain structural units derived from one or more monomers optionally substituted with those selected from the group consisting of styrene, ethylene halide, vinylpyridine, vinylidene fluoride, vinyl ether, vinyl acetate, acrylonitrile, acrylamide, methacrylamide, acrylic acid, methacrylic acid, acrylate, methacrylate, 2-hydroxyethyl acrylate, and combinations thereof. In some embodiments, the binder does not contain structural units derived from monomers having functional groups containing halogens, O, N, S, or combinations thereof.

[0098] In some embodiments, the adhesive is a random copolymer. In other embodiments, the adhesive material is a random copolymer in which at least two monomer units are randomly distributed. In some embodiments, the adhesive material is an alternating copolymer. In other embodiments, the adhesive material is an alternating copolymer in which at least two monomer units are alternately distributed. In some embodiments, the adhesive material is a block copolymer.

[0099] In some embodiments, based on the total molar number of monomer units in the adhesive, the proportion of all hydrophilic structural units in the adhesive is, on a molar basis, about 15% to about 90%, about 15% to about 85%, about 15% to about 80%, about 15% to about 75%, about 15% to about 70%, about 15% to about 65%, about 15% to about 60%, about 15% to about 55%, about 15% to about 50%, about 15% to about 45%, about 15% to about 40%, about 15% to about 35%, about 20% to about 90%, about 20% to about 85%, about 20% to about 80%, about 20% to about 75%, and about 20%. About 70%, about 20% to about 65%, about 20% to about 60%, about 20% to about 55%, about 20% to about 50%, about 20% to about 45%, about 20% to about 40%, about 25% to about 90%, about 25% to about 85%, about 25% to about 80%, about 25% to about 75%, about 25% to about 70%, about 25% to about 65%, about 25% to about 60%, about 25% to about 55%, about 25% to about 50%, about 25% to about 45%, about 30% to about 90%, about 30% to about 85%, about 30% to about 80%, about 30% to about 75%, about 30% to about 70%, about 30% to about 65%, about 30% to about 60%, about 30% to about 55%, about 30% to about 50%, about 35% to about 90%, about 35% to about 85%, about 35% to about 80%, about 35% to about 75%, about 35% to about 70%, about 35% to about 65%, about 35% to about 60%, about 35% to about 55%, about 40% to about 90%, about 40% to about 85%, about 40% to about 80%, about 40% to about 75%, about 40% to about 70%, about 40% to about 65%, about 40% to about 60%, about 45% to about 90%, about 45% to about 85% %, about 45% to about 80%, about 45% to about 75%, about 45% to about 70%, about 45% to about 65%, about 50% to about 90%, about 50% to about 85%, about 50% to about 80%, about 50% to about 75%, about 50% to about 70%, about 55% to about 90%, about 55% to about 85%, about 55% to about 80%, about 55% to about 75%, about 60% to about 90%, about 60% to about 85%, about 65% to about 90%, about 65% to about 85%, about 70% to about 90%, about 75% to about 90%, or about 80% to about 90%.

[0100] In some embodiments, based on the total molar number of monomer units in the adhesive, the proportion of all hydrophilic structural units in the adhesive polymer is about 90% or less, about 85% or less, about 80% or less, about 75% or less, about 70% or less, about 65% or less, about 60% or less, about 55% or less, about 50% or less, about 45% or less, about 40% or less, about 35% or less, or about 30% or less, on a molar basis. In some embodiments, based on the total molar number of monomer units in the adhesive, the proportion of all hydrophilic structural units in the adhesive polymer is about 15% or more, about 20% or more, about 25% or more, about 30% or more, about 35% or more, about 40% or more, about 45% or more, about 50% or more, about 55% or more, about 60% or more, about 65% or more, about 70% or more, or about 75% or more, on a molar basis. In some embodiments, based on the total molar number of monomer units in the binder, the proportion of all hydrophilic structural units in the binder polymer is about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, or about 90% by molar.

[0101] In some embodiments, based on the total molar number of monomer units in the adhesive, the proportion of all hydrophobic structural units in the adhesive is, on a molar basis, about 5% to about 80%, about 5% to about 75%, about 5% to about 70%, about 5% to about 65%, about 5% to about 60%, about 5% to about 55%, about 5% to about 50%, about 5% to about 45%, about 5% to about 40%, about 5% to about 35%, about 5% to about 30%, about 5% to about 25%, about 10% to about 80%, about 10% to about 75%, about 10% to about 70%, about 10% to about 65%, about 10% to about 60%, about 10% to about 55%, about 10% to About 50%, about 10% to about 45%, about 10% to about 40%, about 10% to about 35%, about 10% to about 30%, about 15% to about 80%, about 15% to about 75%, about 15% to about 70%, about 15% to about 65%, about 15% to about 60%, about 15% to about 55%, about 15% to about 50%, about 15% to about 45%, about 15% to about 40%, about 15% to about 35%, about 20% to about 80%, about 20% to about 75%, about 20% to about 70%, about 20% to about 65%, about 20% to about 60%, about 20% to about 55%, about 20% to about 50%, about 20% to about 40%. 5%, about 20% to about 40%, about 25% to about 80%, about 25% to about 75%, about 25% to about 70%, about 25% to about 65%, about 25% to about 60%, about 25% to about 55%, about 25% to about 50%, about 25% to about 45%, about 30% to about 80%, about 30% to about 75%, about 30% to about 70%, about 30% to about 65%, about 30% to about 60%, about 30% to about 55%, about 30% to about 50%, about 35% to about 80%, about 35% to about 75%, about 35% to about 70%, about 35% to about 65%, about 35% to about 60%, about 35% to about 55%. Approximately 40% to approximately 80%, approximately 40% to approximately 75%, approximately 40% to approximately 70%, approximately 40% to approximately 65%, approximately 40% to approximately 60%, approximately 40% to approximately 55%, approximately 40% to approximately 50%, approximately 40% to approximately 45%, approximately 45% to approximately 90%, approximately 45% to approximately 85%, approximately 45% to approximately 80%, approximately 45% to approximately 75%, approximately 45% to approximately 70%, approximately 45% to approximately 65%, approximately 50% to approximately 80%, approximately 50% to approximately 75%, approximately 50% to approximately 70%, approximately 55% to approximately 80%, approximately 55% to approximately 75%, approximately 60% to approximately 80%, approximately 65% ​​to approximately 80%, or approximately 70% to approximately 80%.

[0102] In some embodiments, based on the total molar number of monomer units in the adhesive, the proportion of all hydrophobic structural units in the adhesive polymer is about 80% or less, about 75% or less, about 70% or less, about 65% or less, about 60% or less, about 55% or less, about 50% or less, about 45% or less, about 40% or less, about 35% or less, or about 30% or less, on a molar basis. In some embodiments, based on the total molar number of monomer units in the adhesive, the proportion of all hydrophobic structural units in the adhesive polymer is about 5% or more, about 10% or more, about 20% or more, about 25% or more, about 30% or more, about 35% or more, about 40% or more, about 45% or more, about 50% or more, about 55% or more, about 60% or more, about 65% or more, about 70% or more, or about 75% or more, on a molar basis. In some embodiments, the proportion of all hydrophobic structural units in the binder polymer is about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, or about 80% by molar, based on the total molar number of monomer units in the binder.

[0103] In some embodiments, based on the total molar number of monomer units in the binder, the proportion of one or more structural units derived from carboxylic acid-containing monomers is, on a molar basis, about 15% to about 85%, about 15% to about 80%, about 15% to about 75%, about 15% to about 70%, about 15% to about 65%, about 15% to about 60%, about 15% to about 55%, about 15% to about 50%, about 20% to about 85%, about 20% to about 80%, about 20% to about 75%, about 20% to about 70%, about 20% to about 65%, about 20% to about 60%, about 20% to about 55%, about 20% to about 50%, about 25% to about 85%, about 25% to about 80%, about 25% to about 75%, about 25% to about 70%, about 25% to about 65%, about 25% to about 65%, about 25% to about 85%, about 25% to about 80%, about 25% to about 75%, about 25% to about 70 ...80%, about 25% to about 75%, about 25% to about 70%, about 2 % to 60%, about 25% to 55%, about 25% to 50%, about 30% to 85%, about 30% to 80%, about 30% to 75%, about 30% to 70%, about 30% to 65%, about 30% to 60%, about 35% to 85%, about 35% to 80%, about 35% to 75%, about 35% to 70%, about 35% to 65%, about 35% to 60%, about 40% to 85%, about 40% to 80%, about 40% to 75%, about 40% to 70%, about 45% to 85%, about 45% to 80%, about 45% to 75%, about 45% to 70%, about 50% to 85%, about 50% to 80%, about 50% to 75%, or about 50% to 70%.

[0104] In some embodiments, based on the total number of moles of monomer units in the binder, the proportion of one or more structural units derived from carboxylic acid-containing monomers is about 85% or less, about 80% or less, about 75% or less, about 70% or less, about 69% or less, about 68% or less, about 67% or less, about 66% or less, about 65% or less, about 64% or less, about 63% or less, about 62% or less, about 61% or less, about 60% or less, about 59% or less, about 58% or less, about 57% or less, about 56% or less, about 55% or less, about 54% or less, about 53% or less, about 52% or less, about 51% or less, or about 50% or less, on a molar basis. In some embodiments, based on the total molar number of monomer units in the binder, the proportion of one or more structural units derived from carboxylic acid-containing monomers is about 15% or higher, about 20% or higher, about 25% or higher, about 30% or higher, about 35% or higher, about 40% or higher, about 41% or higher, about 42% or higher, about 43% or higher, about 44% or higher, about 45% or higher, about 46% or higher, about [missing information], on a molar basis. 47% or higher, approximately 48% or higher, approximately 49% or higher, approximately 50% or higher, approximately 51% or higher, approximately 52% or higher, approximately 53% or higher, approximately 54% or higher, approximately 55% or higher, approximately 56% or higher, approximately 57% or higher, approximately 58% or higher, approximately 59% or higher, approximately 60% or higher, approximately 61% or higher, approximately 62% or higher, approximately 63% or higher, approximately 64% or higher, or approximately 65% ​​or higher.

[0105] In some embodiments, based on the total molar number of monomer units in the binder, the proportion of one or more structural units derived from amide-containing monomers is, on a molar basis, about 5% to about 50%, about 5% to about 45%, about 5% to about 40%, about 5% to about 35%, about 5% to about 30%, about 5% to about 25%, about 5% to about 20%, about 5% to about 15%, about 10% to about 50%, about 10% to about 45%, about 10% to about 40%, etc. 0%, about 10% to about 35%, about 10% to about 30%, about 10% to about 25%, about 15% to about 50%, about 15% to about 45%, about 15% to about 35%, about 15% to about 30%, about 20% to about 50%, about 20% to about 45%, about 20% to about 40%, about 25% to about 50%, about 25% to about 45%, about 25% to about 40%, about 30% to about 50%, or about 30% to about 45%.

[0106] In some embodiments, based on the total number of moles of monomer units in the binder, the proportion of one or more structural units derived from amide-containing monomers is about 50% or less, about 45% or less, about 40% or less, about 35% or less, about 34% or less, about 33% or less, about 32% or less, about 31% or less, about 30% or less, about 29% or less, about 28% or less, about 27% or less, about 26% or less, about 25% or less, about 24% or less, about 23% or less, about 22% or less, about 21% or less, about 20% or less, about 19% or less, about 18% or less, about 17% or less, about 16% or less, or about 15% or less, on a molar basis. In some embodiments, based on the total number of moles of monomer units in the binder, the proportion of one or more structural units derived from amide-containing monomers is about 5% or higher, about 10% or higher, about 11% or higher, about 12% or higher, about 13% or higher, about 14% or higher, about 15% or higher, about 16% or higher, about 17% or higher, about 18% or higher, about 19% or higher, about 20% or higher, about 21% or higher, about 22% or higher, about 23% or higher, about 24% or higher, about 25% or higher, about 26% or higher, about 27% or higher, about 28% or higher, about 29% or higher, about 30% or higher, or about 35% or higher on a molar basis.

[0107] In some embodiments, based on the total molar number of monomer units in the binder, the proportion of one or more structural units derived from nitrile-containing monomers is, on a molar basis, about 10% to about 80%, about 10% to about 75%, about 10% to about 70%, about 10% to about 65%, about 10% to about 60%, about 10% to about 55%, about 10% to about 50%, about 10% to about 45%, about 10% to about 40%, about 10% to about 35%, about 10% to about 30%, about 15% to about 80%, about 15% to about 75%, about 15% to about 70%, about 15% to about 65%, about 15% to about 60%, about 15% to about 55%, about 15% to about 50%, about 15% to about 45%, about 15% to about 40%, about 15% to about 35%, about 15% to about 30%, about 20%. % to 80%, about 20% to 75%, about 20% to 70%, about 20% to 65%, about 20% to 60%, about 20% to 55%, about 20% to 50%, about 25% to 80%, about 25% to 75%, about 25% to 70%, about 25% to 65%, about 25% to 60%, about 25% to 55%, about 25% to 50%, about 30% to about 80%, about 30% to about 75%, about 30% to about 70%, about 30% to about 65%, about 30% to about 60%, about 30% to about 55%, about 30% to about 50%, about 35% to about 80%, about 35% to about 75%, about 35% to about 70%, about 35% to about 65%, about 35% to about 60%, about 35% to about 55%, or about 35% to about 50%.

[0108] In some embodiments, based on the total molar number of monomer units in the binder, the proportion of one or more structural units derived from nitrile-containing monomers is about 10% or higher, about 11% or higher, about 12% or higher, about 13% or higher, about 14% or higher, about 15% or higher, about 16% or higher, about 17% or higher, about 18% or higher, about 19% or higher, about 20% or higher, about 25% or higher, about 30% or higher, about 35% or higher, about 40% or higher, about 45% or higher, about 50% or higher, about 55% or higher, or about 60% or higher on a molar basis. In some embodiments, based on the total molar number of monomer units in the binder, the proportion of one or more structural units derived from nitrile-containing monomers is about 80% or less, about 75% or less, about 70% or less, about 65% or less, about 60% or less, about 55% or less, about 50% or less, about 45% or less, about 40% or less, about 35% or less, about 30% or less, or about 25% or less, on a molar basis.

[0109] In some embodiments, the pH value of the adhesive composition is about 7 to about 13, about 7.5 to about 13, about 8 to about 13, about 8.5 to about 13, about 9 to about 13, about 7 to about 12.5, about 7.5 to about 12.5, about 8 to about 12.5, about 8.5 to about 12.5, about 9 to about 12.5, about 7 to about 12, about 7.5 to about 12, about 8 to about 12, about 8.5 to about 12, about 9 to about 12, about 7 to about 11.5, about 7.5 to about 11.5, about 8 to about 11.5, about 8.5 to about 11.5, about 9 to about 11.5, about 7 to about 11, about 7.5 to about 11, about 8 to about 11, about 8.5 to about 11, or about 9 to about 11.

[0110] In some embodiments, the pH value of the adhesive composition is about 13 or less, about 12.5 or less, about 12 or less, about 11.5 or less, about 11 or less, about 10.5 or less, about 10 or less, about 9.5 or less, or about 9 or less. In some embodiments, the pH value of the adhesive composition is about 7 or greater, about 7.5 or greater, about 8 or greater, about 8.5 or greater, about 9 or greater, about 9.2 or greater, about 9.4 or greater, about 9.6 or greater, about 9.8 or greater, about 10 or greater, about 10.2 or greater, about 10.4 or greater, about 10.6 or greater, about 10.8 or greater, or about 11 or greater.

[0111] In binder copolymers, the hydrophilic groups in the hydrophilic structural units readily interact with water because they can form hydrogen bonds or other polar interactions. Therefore, the presence of these hydrophilic groups helps ensure good dispersibility of the copolymer in water. However, the hydrophilic groups of different copolymer chains in the binder can also interact with each other through polar interactions or the formation of hydrogen bonds. Therefore, in the absence of a solvent, for example when a slurry containing an aqueous binder is dried to form an electrode, the copolymer chains of the binder cannot easily slide over each other due to the intermolecular interactions between the hydrophilic groups present between the copolymer chains. This results in a decrease in the flexibility of the binder and the electrode containing the binder. Therefore, additives are added to the electrode slurry to increase the flexibility of the electrode.

[0112] Figure 1 This is a flowchart of one embodiment of the electrode slurry disclosed herein and a method 100 for preparing an electrode using the electrode slurry. In some embodiments, the first suspension is formed by dispersing a binder in a solvent in step 101. In some embodiments, the first suspension further comprises additives.

[0113] In some embodiments, based on the total weight of the first suspension, the respective contents of the binder material and additives in the first suspension are independently, by weight, about 0.1% to about 5%, about 0.2% to about 5%, about 0.3% to about 5%, about 0.4% to about 5%, about 0.5% to about 5%, about 0.6% to about 5%, about 0.7% to about 5%, about 0.8% to about 5%, about 0.9% to about 5%, about 1% to about 5%, about 1.5% to about 5%, about 2% to about 5%, about 2.5% to about 5%, about 0.1% to about 4.5%, about 0.2% to about 4.5%, about 0.3% to about 4.5%, about 0.4% to about 4.5%, about 0.5% to about 4.5%, about 0.6% to about 4.5%, about 0% to about ... 0.7% to about 4.5%, about 0.8% to about 4.5%, about 0.9% to about 4.5%, about 1% to about 4.5%, about 1.5% to about 4.5%, about 2% to about 4.5%, about 2.5% to about 4.5%, about 0.1% to about 4%, about 0.2% to about 4%, about 0.3% to about 4%, about 0.4% to about 4%, about 0.5% to about 4%, about 0.6% to about 4%, about 0.7% to about 4%, about 0.8% to about 4%, about 0.9% to about 4%, about 1% to about 4%, about 1.5% to about 4%, about 2% to about 4%, about 2.5% to about 4%, about 0.1% to about 3.5%, about 0.2% to about 3.5%, about 0.3% to about 3.5%, about 0.4% to about 3. 5%, about 0.5% to about 3.5%, about 0.6% to about 3.5%, about 0.7% to about 3.5%, about 0.8% to about 3.5%, about 0.9% to about 3.5%, about 1% to about 3.5%, about 1.5% to about 3.5%, about 0.1% to about 3%, about 0.2% to about 3%, about 0.3% to about 3%, about 0.4% to about 3%, about 0.5% to about 3%, about 0.6% to about 3%, about 0.7% to about 3%, about 0.8% to about 3%, about 0.9% to about 3%, about 1% to about 3%, about 0.1% to about 2.5%, about 0.2% to about 2.5%, about 0.3% to about 2.5%, about 0.4% to about 2.5%, about 0.5% to about 2.5%, about 0.6% to About 2.5%, about 0.7% to about 2.5%, about 0.8% to about 2.5%, about 0.9% to about 2.5%, about 1% to about 2.5%, about 0.1% to about 2%, about 0.2% to about 2%, about 0.3% to about 2%, about 0.4% to about 2%, about 0.5% to about 2%, about 0.6% to about 2%, about 0.7% to about 2%, about 0.8% to about 2%, about 0.9% to about 2%, about 1% to about 2%, about 0.1% to about 1.5%, about 0.2% to about 1.5%, about 0.3% to about 1.5%, about 0.4% to about 1.5%, about 0.5% to about 1.5%, about 0.6% to about 1.5%, about 0.7% to about 1.5%, about 0.8% to about 1.5%, about 0.9% to about 1.5%, about 1% to about 1.5%, about 0.1% to about 1.2%, about 0.2% to about 1.2%, about 0.4% to about 1.2%, about 0.5% to about 1.2%, about 0.6% to about 1.2%, about 0.7% to about 1.2%, about 0.8% to about 1.2%, about 0.1% to about 1%, about 0.2% to about 1%, about 0.3% to about 1%, about 0.4% to about 1%, about 0.5% to about 1%, about 0.6% to about 1%, or about 0.7% to about 1%.

[0114] In some embodiments, based on the total weight of the first suspension, the respective contents of the binder material and additives in the first suspension are independently, by weight, about 5% or less, about 4.5% or less, about 4% or less, about 3.5% or less, about 3% or less, about 2.5% or less, about 2% or less, about 1.5% or less, or about 1% or less. In some embodiments, based on the total weight of the first suspension, the respective contents of the binder material and additives in the first suspension are independently, by weight, about 0.1% or more, about 0.2% or more, about 0.3% or more, about 0.4% or more, about 0.5% or more, about 0.6% or more, about 0.7% or more, about 0.8% or more, about 0.9% or more, about 1% or more, about 1.5% or more, about 2% or more, about 2.5% or more, or about 3% or more.

[0115] The first suspension can be mixed at any time and at any temperature to achieve good dispersion. The embodiments described below are non-limiting examples of the mixing time and temperature of the first suspension.

[0116] In some embodiments, the first suspension is mixed for about 1 minute to about 60 minutes, about 1 minute to about 50 minutes, about 1 minute to about 45 minutes, about 1 minute to about 40 minutes, about 1 minute to about 30 minutes, about 1 minute to about 25 minutes, about 1 minute to about 20 minutes, about 1 minute to about 15 minutes, about 5 minutes to about 60 minutes, about 5 minutes to about 50 minutes, about 5 minutes to about 45 minutes, about 5 minutes to about 40 minutes, about 5 minutes to about 30 minutes, or about 10 minutes to about 60 minutes. Clock, about 10 minutes to about 50 minutes, about 10 minutes to about 45 minutes, about 10 minutes to about 40 minutes, about 10 minutes to about 30 minutes, about 15 minutes to about 60 minutes, about 15 minutes to about 50 minutes, about 15 minutes to about 45 minutes, about 20 minutes to about 60 minutes, about 20 minutes to about 50 minutes, about 20 minutes to about 45 minutes, about 25 minutes to about 60 minutes, about 25 minutes to about 50 minutes, about 25 minutes to about 45 minutes, or about 30 minutes to about 60 minutes.

[0117] In some embodiments, the first suspension is mixed for about 1 minute or more, about 5 minutes or more, about 10 minutes or more, about 15 minutes or more, about 20 minutes or more, about 25 minutes or more, about 30 minutes or more, about 35 minutes or more, about 40 minutes or more, or about 45 minutes or more. In some embodiments, the first suspension is mixed for about 60 minutes or less, about 55 minutes or less, about 50 minutes or less, about 45 minutes or less, about 40 minutes or less, about 35 minutes or less, about 30 minutes or less, about 25 minutes or less, about 20 minutes or less, or about 15 minutes or less.

[0118] In some embodiments, the temperature of the first suspension is about 10°C to about 60°C, about 10°C to about 50°C, about 10°C to about 40°C, about 10°C to about 35°C, about 10°C to about 30°C, about 10°C to about 25°C, about 15°C to about 60°C, about 15°C to about 50°C, about 15°C to about 40°C, about 20°C to about 60°C, or about 20°C to about 50°C. In some embodiments, the temperature of the first suspension is 60°C or below, 50°C or below, 40°C or below, 35°C or below, 30°C or below, or 25°C or below. In other embodiments, the temperature of the first suspension is 10°C or above, 15°C or above, 20°C or above, 25°C or above, 30°C or above, or 40°C or above. In some embodiments, the temperature at which the first suspension is mixed is about 60°C, about 50°C, about 40°C, about 35°C, about 30°C, about 25°C, about 20°C, about 15°C, or about 10°C. In some embodiments, the first suspension is mixed at room temperature.

[0119] In some embodiments, a second suspension is formed by adding a conductive agent to the first suspension in step 102.

[0120] In some embodiments, the conductive agent is a carbonaceous material selected from the group consisting of carbon, carbon black, graphite, expanded graphite, graphene, graphene nanosheets, carbon fibers, carbon nanofibers, graphitized carbon sheets, carbon nanotubes, carbon nanotubes, activated carbon, mesoporous carbon, and combinations thereof. In some embodiments, the conductive agent does not contain a carbonaceous material.

[0121] In some embodiments, the conductive agent is a conductive polymer. In some embodiments, the conductive polymer is selected from the group consisting of polypyrrole, polyaniline, polyacetylene, polyphenylene sulfide (PPS), polyphenylacetylene (PPV), poly(3,4-ethylenedioxythiophene) (PEDOT), polythiophene, and combinations thereof. In other embodiments, the conductive agent is not a conductive polymer. In some embodiments, the conductive agent also acts as a binder.

[0122] The second suspension can be mixed at any time and at any temperature to ensure good dispersion. The mixing time and temperature can be within the same range as those for the first suspension described above.

[0123] In some embodiments, a third suspension is formed by dispersing the electrode active material into a second suspension in step 103.

[0124] In some embodiments, the electrode paste is used as the cathode, and the electrode active material is a cathode active material. In some embodiments, the cathode active material is selected from LiCoO2, LiNiO2, and LiNi. x Mn y O2, LiCo x Ni y O2, Li 1+ z Ni x Mn y Co 1-x-y O2, LiNi x Co y Al z The group consisting of O2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4, Li2MnO3, LiFeO2, LiFePO4 and combinations thereof, wherein each x is independently 0.1 to 0.9; each y is independently 0 to 0.9; and each z is independently 0 to 0.4.

[0125] In some embodiments, the cathode active material is selected from LiCoO2, LiNiO2, and LiNi x Mn y O2, Li 1+ z Ni x Mn y Co 1-x-y O2(NMC), LiNi x Co y Al z O2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4, LiFeO2, LiFePO4, LiCo x Ni yA group consisting of O2 and its combinations, where each x is independently 0.4 to 0.6; each y is independently 0.2 to 0.4; and each z is independently 0 to 0.1. In other embodiments, the cathode active material is not LiCoO2, LiNiO2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4, LiFeO2 or LiFePO4. In a further embodiment, the cathode active material is not LiNi x Mn y O2, Li 1+z Ni x Mn y Co 1-x-y O2, LiNi x Co y Al z O2 or LiCo x Ni y O2, where each x is independently 0.1 to 0.9; each y is independently 0 to 0.45; and each z is independently 0 to 0.2. In certain embodiments, the cathode active material is Li 1+x Ni a Mn b Co c Al (1-a-b-c) O2; where -0.2 ≤ x ≤ 0.2, 0 ≤ a < 1, 0 ≤ b < 1, 0 ≤ c < 1 and a + b + c ≤ 1.

[0126] In some embodiments, the cathode active material has the general formula LiMPO4, where M is selected from the group consisting of Fe, Co, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge and their combinations. In some embodiments, the cathode active material is selected from the group consisting of LiFePO4, LiCoPO4, LiNiPO4, LiMnPO4, LiMnFePO4, LiMn d Fe (1-d) PO4 and their combinations; where 0 < d < 1. In some embodiments, the cathode active material is LiNi e Mn f O4; where 0.1 ≤ e ≤ 0.9 and 0 ≤ f ≤ 2. In certain embodiments, the cathode active material is dLi2MnO3·(1 - d)LiMO2, where M is selected from the group consisting of Ni, Co, Mn, Fe and their combinations; and where 0 < d < 1. In some embodiments, the cathode active material is Li3V2(PO4)3, LiVPO4F. In certain embodiments, the cathode active material has the general formula Li2MSiO4, where M is selected from the group consisting of Fe, Co, Mn, Ni and their combinations.

[0127] In some embodiments, the cathode active material is doped with a dopant selected from the group consisting of Co, Cr, V, Mo, Nb, Pd, F, Na, Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge, and combinations thereof. In some embodiments, the dopant is not Co, Cr, V, Mo, Nb, Pd, F, Na, Fe, Ni, Mn, Mg, Zn, Ti, La, Ce, Ru, Si, or Ge. In some embodiments, the dopant is not Al, Sn, or Zr.

[0128] In some embodiments, the cathode active material is LiNi. 0.33 Mn 0.33 Co 0.33 O2(NMC333), LiNi 0.4 Mn 0.4 Co 0.2 O2, LiNi 0.5 Mn 0.3 Co 0.2 O2(NMC532), LiNi 0.6 Mn 0.2 Co 0.2 O2(NMC622), LiNi 0.7 Mn 0.15 Co 0.15 O2, LiNi 0.7 Mn 0.1 Co 0.2 O2, LiNi 0.8 Mn 0.1 Co 0.1 O2(NMC811), LiNi 0.92 Mn 0.04 Co 0.04 O2, LiNi 0.8 Co 0.15 Al 0.05 O2 (NCA), LiNiO2 (LNO) and their combinations.

[0129] In other embodiments, the cathode active material is not LiCoO2, LiNiO2, LiMnO2, LiMn2O4, or Li2MnO3. In a further embodiment, the cathode active material is not LiNiO2. 0.33 Mn 0.33 Co 0.33 O2, LiNi 0.4 Mn 0.4 Co 0.2 O2, LiNi 0.5 Mn 0.3 Co 0.2 O2, LiNi0.6 Mn 0.2 Co 0.2 O2, LiNi 0.7 Mn 0.15 Co 0.15 O2, LiNi 0.7 Mn 0.1 Co 0.2 O2, LiNi 0.8 Mn 0.1 Co 0.1 O2, LiNi 0.92 Mn 0.04 Co 0.04 O2 or LiNi 0.8 Co 0.15 Al 0.05 O2.

[0130] In some embodiments, the cathode active material comprises, or is itself, a core-shell composite material having a core and shell structure, wherein the core and shell each independently comprise materials selected from Li. 1+x Ni a Mn b Co c Al (1-a-b-c) O2, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, Li2MnO3, LiCrO2, Li4Ti5O 12 , LiV2O5, LiTiS2, LiMoS2, LiCo a Ni b O2, LiMn a Ni b Lithium transition metal oxides consisting of O2 and combinations thereof, wherein -0.2≤x≤0.2, 0≤a<1, 0≤b<1, 0≤c<1 and a+b+c≤1.

[0131] In some embodiments, each lithium transition metal oxide in the core and shell is independently doped with a dopant selected from the group consisting of Co, Cr, V, Mo, Nb, Pd, F, Na, Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge, and combinations thereof. In some embodiments, the core and shell each independently comprise two or more doped lithium transition metal oxides. In some embodiments, the two or more doped lithium transition metal oxides are uniformly distributed on the core and / or shell. In some embodiments, the two or more doped lithium transition metal oxides are non-uniformly distributed on the core and / or shell.

[0132] In some embodiments, the cathode active material comprises, or is itself, a core-shell composite material comprising a core containing a lithium transition metal oxide and a shell containing a transition metal oxide. In some embodiments, the lithium transition metal oxide is selected from Li... 1+x Ni a Mn b Co c Al (1-a-b-c) O2, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, Li2MnO3, LiCrO2, Li4Ti5O 12 , LiV2O5, LiTiS2, LiMoS2, LiFePO4, LiCo a Ni b O2, LiMn a Ni b The group consisting of O2 and its combinations; wherein -0.2≤x≤0.2, 0≤a<1, 0≤b<1, 0≤c<1, and a+b+c≤1. In some embodiments, the core comprises a nucleus selected from LiNi. 0.33 Mn 0.33 Co 0.33 O2, LiNi 0.4 Mn 0.4 Co 0.2 O2, LiNi 0.5 Mn 0.3 Co 0.2 O2, LiNi 0.6 Mn 0.2 Co 0.2 O2, LiNi 0.7 Mn 0.15 Co 0.15 O2, LiNi 0.7 Mn 0.1 Co 0.2 O2, LiNi 0.8 Mn 0.1 Co 0.1 O2, LiNi 0.92 Mn 0.04 Co 0.04 O2, LiNi 0.8 Co 0.15 Al 0.05 Nickel-containing lithium transition metal oxides comprising the group consisting of O2, LiNiO2, and combinations thereof. In some embodiments, the transition metal oxide is selected from the group consisting of Fe2O3, MnO2, Al2O3, MgO, ZnO, TiO2, La2O3, CeO2, SnO2, ZrO2, RuO2, and combinations thereof. In some embodiments, the shell comprises a lithium transition metal oxide and a transition metal oxide.

[0133] In some embodiments, the cathode active material comprises, or is itself, a core-shell composite material having a core and shell structure, wherein the core and shell each independently comprise materials selected from Li. 1+x Ni a Mn b Co c Al (1-a-b-c) O2, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, Li2MnO3, LiCrO2, Li4Ti5O 12 Lithium transition metal oxides belonging to the group consisting of LiV₂O₅, LiTiS₂, LiMoS₂, LiFePO₄, and combinations thereof, wherein -0.2 ≤ x ≤ 0.2, 0 ≤ a < 1, 0 ≤ b < 1, 0 ≤ c < 1, and a + b + c ≤ 1. In some embodiments, at least one of the core or shell comprises lithium selected from LiNi. 0.33 Mn 0.33 Co 0.33 O2, LiNi 0.4 Mn 0.4 Co 0.2 O2, LiNi 0.5 Mn 0.3 Co 0.2 O2, LiNi 0.6 Mn 0.2 Co 0.2 O2, LiNi 0.7 Mn 0.15 Co 0.15 O2, LiNi 0.7 Mn 0.1 Co 0.2 O2, LiNi 0.8 Mn 0.1 Co 0.1 O2, LiNi 0.92 Mn 0.04 Co 0.04 O2, LiNi 0.8 Co 0.15 Al 0.05 Nickel-containing lithium transition metal oxides consisting of O2, LiNiO2, and combinations thereof.

[0134] In some embodiments, the core and shell each independently comprise two or more lithium transition metal oxides. In some embodiments, one of the core or shell comprises only one lithium transition metal oxide, while the other comprises two or more lithium transition metal oxides. The lithium transition metal oxides in the core and shell may be the same, different, or partially different. In some embodiments, the two or more lithium transition metal oxides are uniformly distributed on the core. In some embodiments, the two or more lithium transition metal oxides are non-uniformly distributed on the core. In some embodiments, the cathode active material is not a core-shell composite material.

[0135] In some embodiments, the diameter of the core is about 1 μm to about 15 μm, about 3 μm to about 15 μm, about 3 μm to about 10 μm, about 5 μm to about 10 μm, about 5 μm to about 45 μm, about 5 μm to about 35 μm, about 5 μm to about 25 μm, about 10 μm to about 45 μm, about 10 μm to about 40 μm, about 10 μm to about 35 μm, about 10 μm to about 25 μm, about 15 μm to about 45 μm, about 15 μm to about 30 μm, about 15 μm to about 25 μm, about 20 μm to about 35 μm, or about 20 μm to about 30 μm. In some embodiments, the shell thickness is about 1 μm to about 45 μm, about 1 μm to about 35 μm, about 1 μm to about 25 μm, about 1 μm to about 15 μm, about 1 μm to about 10 μm, about 1 μm to about 5 μm, about 3 μm to about 15 μm, about 3 μm to about 10 μm, about 5 μm to about 10 μm, about 10 μm to about 35 μm, about 10 μm to about 20 μm, about 15 μm to about 30 μm, about 15 μm to about 25 μm, or about 20 μm to about 35 μm. In some embodiments, the diameter or thickness ratio of the core to the shell is in the range of 15:85 to 85:15, 25:75 to 75:25, 30:70 to 70:30, or 40:60 to 60:40. In some embodiments, the volume or weight ratio of the core to the shell is 95:5, 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, or 30:70.

[0136] In some embodiments, the electrode paste is used as the anode, and the electrode active material is an anode active material. In some embodiments, the anode active material is selected from natural graphite particles, synthetic graphite particles, Sn (tin) particles, Li4Ti5O 12 A group consisting of particles, Si (silicon) particles, Si-C composite particles, and combinations thereof.

[0137] In some embodiments, the particle size D50 of the electrode active material is about 0.1 μm to about 20 μm, about 0.3 μm to about 20 μm, about 0.5 μm to about 20 μm, about 0.8 μm to about 20 μm, about 1 μm to about 20 μm, about 2 μm to about 20 μm, about 3 μm to about 20 μm, about 4 μm to about 20 μm, about 5 μm to about 20 μm, about 6 μm to about 20 μm, about 8 μm to about 20 μm, about 10 μm to about 20 μm, about 12 μm to about 20 μm, about 14 μm to about 20 μm, about 3 μm to about 18 μm, about 4 μm to about 18 μm, about 5 μm to about 18 μm, about 6 μm to about 18 μm, about 6 μm to about 18 μm, about 10 μm to about 20 μm, about 12 μm to about 20 μm, about 14 μm to about 20 μm, about 3 μm to about 18 μm, about 4 μm to about 18 μm, about 5 ...18 μm, about 10 μm to about 18 μm, about 10 μm to about 18 μm, about 10 μm to μm to about 18μm, about 8μm to about 18μm, about 10μm to about 18μm, about 12μm to about 18μm, about 3μm to about 16μm, about 4μm to about 16μm, about 5μm to about 16μm, about 6μm to about 16μm, about 8μm to about 16μm, about 3μm to about 15μm, about 4μm to about 15μm, about 5μm to about 15μm, about 6μm to about 15μm, about 8μm to about 15μm, about 3μm to about 14μm, about 4μm to about 14μm, about 5μm to about 14μm, about 6μm to about 14μm, about 8μm to about 14μm, about 3μm to about 12μm, about 4 μm to about 12μm, about 5μm to about 12μm, about 6μm to about 12μm, about 3μm to about 10μm, about 4μm to about 10μm, about 5μm to about 10μm, about 0.1μm to about 5μm, about 0.3μm to about 5μm, about 0.5μm to about 5μm, about 0.8μm to about 5μm, about 1μm to about 5μm, about 2μm to about 5μm, about 0.1μm to about 4μm, about 0.3μm to about 4μm, about 0.5μm to about 4μm, about 0.8μm to about 4μm, about 1μm to about 4μm, about 2μm to about 4μm, about 0.1μm to about 3μm, about 0.3μm to about 3μm m, about 0.5 μm to about 3 μm, about 0.8 μm to about 3 μm, about 1 μm to about 3 μm, about 0.1 μm to about 2.5 μm, about 0.3 μm to about 2.5 μm, about 0.5 μm to about 2.5 μm, about 0.8 μm to about 2.5 μm, about 1 μm to about 2.5 μm, about 2 μm to about 2.5 μm, about 0.1 μm to about 2 μm, about 0.3 μm to about 2 μm, about 0.5 μm to about 2 μm, about 0.8 μm to about 2 μm, about 1 μm to about 2 μm, about 0.1 μm to about 1 μm, about 0.3 μm to about 1 μm, about 0.5 μm to about 1 μm or about 0.8 μm to about 1 μm.

[0138] In some embodiments, the particle size D50 of the electrode active material is about 20 μm or less, about 19 μm or less, about 18 μm or less, about 17 μm or less, about 16 μm or less, about 15 μm or less, about 14 μm or less, about 13 μm or less, about 12 μm or less, about 11 μm or less, about 10 μm or less, about 9 μm or less, about 8 μm or less, about 7 μm or less, about 6 μm or less, about 5 μm or less, about 4 μm or less, or about 3 μm or less. In some embodiments, the particle size D50 of the electrode active material is about 0.1 μm or greater, about 0.2 μm or greater, about 0.5 μm or greater, about 1 μm or greater, about 2 μm or greater, about 3 μm or greater, about 4 μm or greater, about 5 μm or greater, about 6 μm or greater, about 7 μm or greater, about 8 μm or greater, about 9 μm or greater, about 10 μm or greater, about 11 μm or greater, about 12 μm or greater, about 13 μm or greater, about 14 μm or greater, or about 15 μm or greater.

[0139] In some embodiments, the binder and conductive agent can be mixed in the first suspension before the additive is added. This can be advantageous because it allows for better dispersion of the material in the second suspension. In some embodiments, the binder, conductive agent, and additive can be mixed to form the first suspension. The electrode active material can then be dispersed in the first suspension to form the second suspension. In other embodiments, the binder and additive can be mixed to form the first suspension. Subsequently, the electrode active material and / or conductive agent can be dispersed in the first suspension to form the second suspension. If only one of the electrode active material or conductive agent is added to form the second suspension, the other can then be dispersed in the second suspension to form a third suspension.

[0140] There is no specific order in which the components of the electrode slurry are added, provided that they can be thoroughly mixed. Binders, additives, electrode active materials, and conductive agents can each be added at any step of the process before the formation of a homogenized electrode slurry.

[0141] The third suspension is homogenized by a homogenizer to obtain a homogenized electrode slurry. The homogenizer may be equipped with a temperature control system, and the temperature of the third suspension may be controlled by this temperature control system. Any homogenizer capable of reducing or eliminating particle aggregation and / or promoting uniform distribution of slurry components can be used in this invention. Uniform distribution plays an important role in preparing batteries with good battery performance. In some embodiments, the homogenizer is a planetary mixer, a stirred mixer, a mixer, and an ultrasonic generator.

[0142] The third suspension can be homogenized at any temperature, provided a homogenized electrode slurry can be obtained. In some embodiments, the homogenization temperature of the third suspension is about 10°C to about 40°C, about 10°C to about 35°C, about 10°C to about 30°C, about 10°C to about 25°C, about 15°C to about 40°C, about 15°C to about 35°C, about 15°C to about 30°C, or about 20°C to about 40°C. In some embodiments, the homogenization temperature of the third suspension is about 40°C or lower, about 35°C or lower, about 30°C or lower, about 25°C or lower, about 20°C or lower, or about 15°C or lower. In some embodiments, the homogenization temperature of the third suspension is about 10°C or higher, about 15°C or higher, about 20°C or higher, or about 25°C or higher. In some embodiments, the third suspension is homogenized at room temperature.

[0143] In some embodiments, the planetary mixer includes at least one planetary impeller and at least one high-speed dispersing impeller. In some embodiments, the planetary impeller rotates at a speed of about 20 rpm to about 200 rpm, about 20 rpm to about 150 rpm, about 30 rpm to about 150 rpm, or about 50 rpm to about 100 rpm. In some embodiments, the dispersing impeller rotates at a speed of about 1000 rpm to about 4000 rpm, about 1000 rpm to about 3500 rpm, about 1000 rpm to about 3000 rpm, about 1000 rpm to about 2000 rpm, about 1500 rpm to about 3000 rpm, or about 1500 rpm to about 2500 rpm.

[0144] In some embodiments, the ultrasound generator is an ultrasound bath, a probe-type ultrasound generator, or an ultrasound flow cell. In some embodiments, the ultrasound generator operates at power densities of about 10 W / L to about 100 W / L, about 20 W / L to about 100 W / L, about 30 W / L to about 100 W / L, about 40 W / L to about 80 W / L, about 40 W / L to about 70 W / L, about 40 W / L to about 60 W / L, about 40 W / L to about 50 W / L, about 50 W / L to about 60 W / L, about 20 W / L to about 80 W / L, about 20 W / L to about 60 W / L, or about 20 W / L to about 40 W / L. In some implementations, the ultrasonic generator operates at power densities of about 10 W / L, about 20 W / L, about 30 W / L, about 40 W / L, about 50 W / L, about 60 W / L, about 70 W / L, about 80 W / L, about 90 W / L, or about 100 W / L.

[0145] The third suspension can be homogenized at any time period, provided a homogenized electrode slurry can be obtained. In some embodiments, the homogenization time period for the third suspension is approximately 10 minutes to approximately 6 hours, approximately 10 minutes to approximately 5 hours, approximately 10 minutes to approximately 4 hours, approximately 10 minutes to approximately 3 hours, approximately 10 minutes to approximately 2 hours, approximately 10 minutes to approximately 1 hour, approximately 10 minutes to approximately 30 minutes, approximately 30 minutes to approximately 3 hours, approximately 30 minutes to approximately 2 hours, approximately 30 minutes to approximately 1 hour, approximately 1 hour to approximately 6 hours, approximately 1 hour to approximately 5 hours, approximately 1 hour to approximately 4 hours, approximately 1 hour to approximately 3 hours, approximately 1 hour to approximately 2 hours, approximately 2 hours to approximately 6 hours, approximately 2 hours to approximately 4 hours, approximately 2 hours to approximately 3 hours, approximately 3 hours to approximately 5 hours, or approximately 4 hours to approximately 6 hours. In some embodiments, the homogenization time period for the third suspension is approximately 6 hours or less, approximately 5 hours or less, approximately 4 hours or less, approximately 3 hours or less, approximately 2 hours or less, approximately 1 hour or less, or approximately 30 minutes or less. In some embodiments, the homogenization time of the third suspension is about 4 hours or more, about 3 hours or more, about 2 hours or more, about 1 hour or more, about 30 minutes or more, about 20 minutes or more, or about 10 minutes or more.

[0146] In some embodiments, the third suspension is degassed briefly under reduced pressure before homogenization to remove trapped air bubbles. In some embodiments, the pressure during degassed operation is approximately 1 kPa to approximately 20 kPa, approximately 1 kPa to approximately 15 kPa, approximately 1 kPa to approximately 10 kPa, approximately 5 kPa to approximately 20 kPa, approximately 5 kPa to approximately 15 kPa, or approximately 10 kPa to approximately 20 kPa. In some embodiments, the pressure during degassed operation is approximately 20 kPa or less, approximately 15 kPa or less, or approximately 10 kPa or less. In some embodiments, the degassed operation is performed for approximately 30 minutes to approximately 4 hours, approximately 1 hour to approximately 4 hours, approximately 2 hours to approximately 4 hours, or approximately 30 minutes to approximately 2 hours. In some embodiments, the degassed operation is performed for approximately 4 hours or less, approximately 2 hours or less, or approximately 1 hour or less.

[0147] In some embodiments, the third suspension is degassed after homogenization, using the pressure and time period described in the step of degasing the third suspension before homogenization.

[0148] In some embodiments, the first and second suspensions can be degassed independently before or after mixing, using the pressure and time period described in the degasing step performed before homogenizing the third suspension.

[0149] In some embodiments, the pH value of the homogenized electrode slurry is about 8 to about 14, about 8 to about 13.5, about 8 to about 13, about 8 to about 12.5, about 8 to about 12, about 8 to about 11.5, about 8 to about 11, about 8 to about 10.5, about 8 to about 10, about 9 to about 14, about 9 to about 13, about 9 to about 12, about 9 to about 11, about 10 to about 14, about 10 to about 13, about 10 to about 12, about 10.5 to about 14, about 10.5 to about 13.5, about 10.5 to about 13, about 10.5 to about 12.5, about 11 to about 14, or about 12 to about 14. In some embodiments, the homogenized electrode slurry has a pH of about 14 or lower, about 13.5 or lower, about 13 or lower, about 12.5 or lower, about 12 or lower, about 11.5 or lower, about 11 or lower, about 10.5 or lower, about 10 or lower, or about 9.5 or lower. In some embodiments, the homogenized electrode slurry has a pH of about 8 or higher, about 8.5 or higher, about 9 or higher, about 9.5 or higher, about 10 or higher, about 10.5 or higher, about 11 or higher, about 11.5 or higher, or about 12 or higher.

[0150] In some embodiments, the pH change observed during homogenization is about 0.01 pH units to about 0.5 pH units, about 0.01 pH units to about 0.45 pH units, about 0.01 pH units to about 0.4 pH units, about 0.01 pH units to about 0.35 pH units, about 0.01 pH units to about 0.3 pH units, about 0.01 pH units to about 0.25 pH units, about 0.01 pH units to about 0.2 pH units, about 0.01 pH units to about 0.15 pH units, or about 0.01 pH units to about 0.1 pH units. In some embodiments, the pH decrease observed during homogenization is about 0.5 pH units or less, about 0.45 pH units or less, about 0.4 pH units or less, about 0.35 pH units or less, about 0.3 pH units or less, about 0.2 pH units or less, or about 0.1 pH units or less.

[0151] In some embodiments, based on the total weight of the solids content of the homogenized electrode slurry, the content of binder and conductive agent in the homogenized electrode slurry is independently, by weight, about 0.5% to about 5%, about 0.5% to about 4.5%, about 0.5% to about 4%, about 0.5% to about 3.5%, about 0.5% to about 3%, about 1% to about 5%, about 1% to about 4.5%, about 1% to about 4%, about 1% to about 3.5%, about 1.5% to about 5%, about 1.5% to about 4.5%, or about 2% to about 5%. In some embodiments, based on the total weight of the solids content of the homogenized electrode slurry, the content of binder and conductive agent in the homogenized electrode slurry is independently, by weight, about 0.5% or more, about 1% or more, about 1.5% or more, about 2% or more, about 2.5% or more, about 3% or more, or about 3.5% or more. In some embodiments, based on the total weight of the solids content of the homogenized electrode paste, the content of binder and conductive agent in the homogenized electrode paste is independently about 5% or less, about 4.5% or less, about 4% or less, about 3.5% or less, or about 3% or less by weight.

[0152] In some embodiments, the weight of the binder material in the homogenized electrode slurry is greater than, less than, or equal to the weight of the conductive agent. In some embodiments, the weight ratio of the binder material to the conductive agent is about 1:10 to about 10:1, about 1:10 to about 5:1, about 1:10 to about 1:1, about 1:10 to about 1:5, about 1:5 to about 5:1, about 1:3 to about 3:1, about 1:2 to about 2:1, or about 1:1.5 to about 1.5:1.

[0153] In some embodiments, based on the total weight of the homogenized electrode slurry, the content of electrode active material in the homogenized electrode slurry is about 20% or more, about 30% or more, about 35% or more, about 40% or more, about 45% or more, about 50% or more, about 55% or more, or about 60% or more by weight. In some embodiments, based on the total weight of the homogenized electrode slurry, the content of electrode active material in the homogenized electrode slurry is about 50% or less, about 55% or less, about 60% or less, about 65% or less, about 70% or less, about 75% or less, or about 80% or less by weight.

[0154] In some embodiments, based on the total weight of the homogenized electrode slurry, the content of electrode active material in the homogenized electrode slurry is, by weight, about 20% to about 80%, about 20% to about 75%, about 20% to about 70%, about 20% to about 65%, about 20% to about 60%, about 20% to about 55%, about 20% to about 50%, about 25% to about 80%, about 25% to about 75%, about 25% to about 70%, about The content of electrode active material in the homogenized electrode slurry is approximately 25% to 65%, approximately 25% to 60%, approximately 25% to 55%, approximately 25% to 50%, approximately 30% to 80%, approximately 30% to 75%, approximately 30% to 70%, approximately 30% to 65%, approximately 30% to 60%, approximately 40% to 80%, approximately 40% to 75%, approximately 40% to 70%, approximately 40% to 65%, approximately 50% to 80%, or approximately 50% to 75% by weight. In some embodiments, based on the total weight of the homogenized electrode slurry, the content of electrode active material in the homogenized electrode slurry is approximately 20%, approximately 30%, approximately 45%, approximately 50%, approximately 65%, approximately 70%, approximately 75%, or approximately 80% by weight.

[0155] In some embodiments, based on the total weight of the solids content of the homogenized electrode slurry, the content of electrode active material in the homogenized electrode slurry is about 40% or more, about 45% or more, about 50% or more, about 55% or more, about 60% or more, about 65% or more, about 70% or more, about 75% or more, about 80% or more, about 85% or more, or about 90% or more by weight. In some embodiments, based on the total weight of the solids content of the homogenized electrode slurry, the content of electrode active material in the homogenized electrode slurry is about 99% or less, about 95% or less, about 90% or less, about 85% or less, about 80% or less, about 75% or less, or about 70% or less by weight.

[0156] In some embodiments, based on the total weight of the solids content of the homogenized electrode slurry, the content of electrode active material in the homogenized electrode slurry is, by weight, about 40% to about 99%, about 40% to about 95%, about 40% to about 90%, about 40% to about 85%, about 40% to about 80%, about 40% to about 75%, about 40% to about 70%, about 50% to about 99%, about 50% to about 95%, about 50% to about 90%, about 50% to about 85%, about 50% to about 80%, and about 50% to about 75%. The content of electrode active material in the homogenized electrode slurry is approximately 40%, 50%, 60%, 70%, 75%, 80%, 85%, 90%, 93%, or 95% by weight, based on the total weight of the solids content of the homogenized electrode slurry. In some embodiments, the content of electrode active material in the homogenized electrode slurry is approximately 40%, 50%, 60%, 70%, 75%, 80%, 85%, 90%, 93%, or 95% by weight, based on the total weight of the solids content of the homogenized electrode slurry.

[0157] In some embodiments, the particle size D50 of the homogenized electrode slurry is about 3 μm to about 20 μm, about 4 μm to about 20 μm, about 5 μm to about 20 μm, about 6 μm to about 20 μm, about 8 μm to about 20 μm, about 10 μm to about 20 μm, about 12 μm to about 20 μm, about 14 μm to about 20 μm, about 3 μm to about 18 μm, about 4 μm to about 18 μm, about 5 μm to about 18 μm, about 6 μm to about 18 μm, about 8 μm to about 18 μm, about 10 μm to about 18 μm, about 12 μm to about 18 μm, about 3 μm to about 16 μm, about 4 μm to about 16 μm, about 5 μm to about 16 μm, about 5 μm to about 16 μm, about 5 μm to about 16 μm, about 10 μm to about 18 μm, about 12 μm to about 18 μm, about 3 μm to about 16 μm, about 4 μm to about 16 μm, about 5 μm to about 16 μm, about 5 μm to about 16 μm, about 10 μm to about 18 μm, about 10 μm to about 18 μm, about 10 μm to about 18 μm, about 10 μm to about 18 μm, about 10 μm to about 10 ... μm to about 16μm, about 6μm to about 16μm, about 8μm to about 16μm, about 3μm to about 15μm, about 4μm to about 15μm, about 5μm to about 15μm, about 6μm to about 15μm, about 8μm to about 15μm, about 3μm to about 14μm, about 4μm to about 14μm, about 5μm to about 14μm, about 6μm to about 14μm, about 8μm to about 14μm, about 3μm to about 12μm, about 4μm to about 12μm, about 5μm to about 12μm, about 6μm to about 12μm, about 3μm to about 10μm, about 4μm to about 10μm or about 5μm to about 10μm.

[0158] In some embodiments, the particle size D50 of the homogenized electrode slurry is about 20 μm or less, about 19 μm or less, about 18 μm or less, about 17 μm or less, about 16 μm or less, about 15 μm or less, about 14 μm or less, about 13 μm or less, about 12 μm or less, about 11 μm or less, about 10 μm or less, about 9 μm or less, about 8 μm or less, about 7 μm or less, about 6 μm or less, or about 5 μm or less. In some embodiments, the particle size D50 of the homogenized electrode slurry is about 3 μm or greater, about 4 μm or greater, about 5 μm or greater, about 6 μm or greater, about 7 μm or greater, about 8 μm or greater, about 9 μm or greater, about 10 μm or greater, about 11 μm or greater, about 12 μm or greater, about 13 μm or greater, about 14 μm or greater, or about 15 μm or greater.

[0159] In some embodiments, based on the total weight of the homogenized electrode paste, the solids content of the homogenized electrode paste is about 40% to about 80%, about 45% to about 75%, about 45% to about 70%, about 45% to about 65%, about 45% to about 60%, about 50% to about 80%, about 50% to about 75%, about 50% to about 70%, about 55% to about 80%, about 55% to about 75%, about 55% to about 70%, or about 60% to about 80% by weight. In some embodiments, based on the total weight of the homogenized electrode paste, the solids content of the homogenized electrode paste is about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, or about 80% by weight. In some embodiments, the solids content of the homogenized electrode paste is at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, or at least 70% by weight, based on the total weight of the homogenized electrode paste. In some embodiments, the solids content of the homogenized electrode paste is at most 80%, at most 75%, at most 70%, at most 65%, at most 60%, at most 55%, or at most 50% by weight, based on the total weight of the homogenized electrode paste.

[0160] In some embodiments, the solvents for the first, second, and third suspensions and the homogenized electrode slurry are independently water. Some non-limiting examples of water include tap water, bottled water, purified water, pure water, distilled water, deionized water, D2O, and combinations thereof.

[0161] In some embodiments, the solvents of the first, second, and third suspensions and the homogenized electrode slurry are independently solvent mixtures comprising water as a major component and volatile solvents other than water (e.g., alcohols, lower aliphatic ketones, lower alkyl acetates, etc.) as minor components. According to the invention, based on the total weight or volume of the solvent mixture, the water content in each of the first, second, and third suspensions and the homogenized electrode slurry is at least 50%.

[0162] Any solvent miscible with water may be used as a minor component. Some non-limiting examples of such a minor component (i.e., solvent other than water) include alcohols, lower aliphatic ketones, lower alkyl acetates, and combinations thereof. Some non-limiting examples of alcohols include C1-C4 alcohols, such as methanol, ethanol, isopropanol, n-propanol, butanol, and combinations thereof. Some non-limiting examples of lower aliphatic ketones include acetone, dimethyl ketones, and methyl ethyl ketones. Some non-limiting examples of lower alkyl acetates include ethyl acetate, isopropyl acetate, and propyl acetate.

[0163] In some embodiments, the volatile solvent or minor component is selected from the group consisting of methyl ethyl ketone, ethanol, ethyl acetate, isopropanol, n-propanol, tert-butanol, n-butanol, and combinations thereof. In some embodiments, the volume ratio of water to the minor component is from about 51:49 to about 99:1. In some embodiments, the solvents of the first, second, and third suspensions and the homogenized electrode slurry are independently free of alcohols, aliphatic ketones, alkyl acetates, or combinations thereof.

[0164] The viscosity of the homogenized electrode paste is preferably about 8000 mPa·s or less. In some embodiments, the viscosity of the homogenized electrode paste is about 1,000 mPa·s to about 8,000 mPa·s, about 1,000 mPa·s to about 7,000 mPa·s, about 1,000 mPa·s to about 6,000 mPa·s, about 1,000 mPa·s to about 5,500 mPa·s, about 1,000 mPa·s to about 5,000 mPa·s, about 1,000 mPa·s to about 4,500 mPa·s, or about 1,000 mPa·s to about 4,000 mPa·s. ,000 mPa·s, about 1,000 mPa·s to about 3,500 mPa·s, about 1,000 mPa·s to about 3,000 mPa·s, about 2,000 mPa·s to about 8,000 mPa·s, about 2,000 mPa·s to about 7,000 mPa·s, about 2,000 mPa·s to about 6,000 mPa·s, about 2,000 mPa·s to about 5,500 mPa·s, about 2,000 mPa·s to about 5,000 mPa·s, about 2,000 mPa·s to about 4,500 mPa·s, about 2,000 mPa·s to about 4,000 mPa·s, about 3,000 mPa·s to about 8,000 mPa·s, about 3,000 mPa·s to about 7,000 mPa·s, about 3,000 mPa·s to about 6,500 mPa·s, about 3,000 mPa·s to about 6,000 mPa·s, about 3,000 mPa·s to about 5,500 mPa·s, about 3,000 mPa·s to Approximately 5,000 mPa·s, approximately 3,500 mPa·s to approximately 8,000 mPa·s, approximately 3,500 mPa·s to approximately 7,000 mPa·s, approximately 3,500 mPa·s to approximately 6,500 mPa·s, approximately 3,500 mPa·s to approximately 6,000 mPa·s, approximately 3,500 mPa·s to approximately 5,500 mPa·s, approximately 3,500 mPa·s to approximately 5,000 mPa·s, or approximately 3,500 mPa·s to approximately 4,500 mPa·s.

[0165] In some embodiments, the viscosity of the homogenized electrode slurry is about 8,000 mPa·s or less, about 7,500 mPa·s or less, about 7,000 mPa·s or less, about 6,500 mPa·s or less, about 6,000 mPa·s or less, about 5,500 mPa·s or less, about 5,000 mPa·s or less, about 4,500 mPa·s or less, about 4,000 mPa·s or less, about 3,500 mPa·s or less, about 3,000 mPa·s or less, about 2,500 mPa·s or less, or about 2,000 mPa·s or less. In some embodiments, the viscosity of the homogenized electrode slurry is about 1,000 mPa·s, about 1,500 mPa·s, about 2,000 mPa·s, about 2,500 mPa·s, about 3,000 mPa·s, about 3,500 mPa·s, about 4,000 mPa·s, about 4,500 mPa·s, about 5,000 mPa·s, about 5,500 mPa·s, about 6,000 mPa·s, about 6,500 mPa·s, about 7,000 mPa·s, about 7,500 mPa·s, or about 8,000 mPa·s. Therefore, the resulting slurry can be completely mixed or homogenized.

[0166] In conventional methods for preparing electrode slurries, dispersants are used to assist in dispersing the electrode active material, conductive agent, and binder within the slurry. One advantage of this invention is that the slurry components can be uniformly dispersed at room temperature without the use of a dispersant. This is because aqueous binders are readily dispersed in water-based slurries. In some embodiments, the method of this invention does not include the step of adding a dispersant to one or more of the first suspension, second suspension, third suspension, and homogenized electrode slurry. In some embodiments, each of the first suspension, second suspension, third suspension, and homogenized electrode slurry is independently free of a dispersant.

[0167] After the slurry components are uniformly mixed, the homogenized electrode slurry can be applied to the current collector to form a coating film on the current collector, and then dried in step 104. The current collector is used to collect electrons generated by the electrochemical reaction of the electrode active material or to provide electrons required for the electrochemical reaction. In some embodiments, the current collector can be in the form of a foil, sheet, or film. In some embodiments, the current collector is stainless steel, titanium, nickel, aluminum, copper, or an alloy thereof. In other embodiments, the current collector is a conductive resin.

[0168] In some embodiments, the current collector has a two-layer structure comprising an outer layer and an inner layer, wherein the outer layer comprises a conductive material and the inner layer comprises an insulating material or another conductive material; for example, aluminum with a conductive resin layer or a polymer insulating material coated with an aluminum film.

[0169] In some embodiments, the current collector has a three-layer structure comprising an outer layer, a middle layer, and an inner layer, wherein the outer and inner layers comprise a conductive material and the middle layer comprises an insulating material or another conductive material; for example, a plastic substrate coated with a metal film on both sides. In some embodiments, each of the outer, middle, and inner layers is independently stainless steel, titanium, nickel, aluminum, copper, or an alloy thereof, or a conductive resin. In some embodiments, the insulating material is a polymer material selected from the group consisting of polycarbonate, polyacrylate, polyacrylonitrile, polyester, polyamide, polystyrene, polyurethane, epoxy resin, poly(acrylonitrile-butadiene-styrene), polyimide, polyolefin, polyethylene, polypropylene, polyphenylene sulfide, poly(vinyl ester), polyvinyl chloride, polyether, polyphenylene ether, cellulose polymers, and combinations thereof. In some embodiments, the current collector has a structure with more than three layers. In some embodiments, the current collector is coated with a protective coating. In some embodiments, the protective coating comprises a carbon-containing material. In some embodiments, the current collector is not coated with a protective coating.

[0170] In some embodiments, the thickness of the electrode layer on the current collector is about 5 μm to about 120 μm, about 5 μm to about 100 μm, about 5 μm to about 80 μm, about 5 μm to about 50 μm, about 5 μm to about 25 μm, about 10 μm to about 90 μm, about 10 μm to about 50 μm, about 10 μm to about 30 μm, about 15 μm to about 90 μm, about 20 μm to about 90 μm, about 25 μm to about 90 μm, about 25 μm to about 80 μm, about 25 μm to about 75 μm, about 25 μm to about 50 μm, about 30 μm to about 90 μm, about 3 0 μm to about 80 μm, about 35 μm to about 120 μm, about 35 μm to about 115 μm, about 35 μm to about 110 μm, about 35 μm to about 105 μm, about 35 μm to about 100 μm, about 35 μm to about 95 μm, about 35 μm to about 90 μm, about 35 μm to about 85 μm, about 35 μm to about 80 μm, about 35 μm to about 75 μm, about 40 μm to about 120 μm, about 50 μm to about 120 μm, about 60 μm to about 120 μm, about 70 μm to about 120 μm, or about 70 μm to about 115 μm.

[0171] In some embodiments, the thickness of the electrode layer on the current collector is about 5 μm or greater, about 10 μm or greater, about 15 μm or greater, about 20 μm or greater, about 25 μm or greater, about 30 μm or greater, about 35 μm or greater, about 40 μm or greater, about 45 μm or greater, about 50 μm or greater, about 55 μm or greater, about 60 μm or greater, about 65 μm or greater, about 70 μm or greater, about 75 μm or greater, or about 80 μm or greater. In some embodiments, the thickness of the electrode layer on the current collector is about 120 μm or less, about 115 μm or less, about 110 μm or less, about 105 μm or less, about 100 μm or less, about 95 μm or less, about 90 μm or less, about 85 μm or less, about 80 μm or less, about 75 μm or less, about 70 μm or less, about 65 μm or less, about 60 μm or less, about 55 μm or less, about 50 μm or less, about 45 μm or less, or about 40 μm or less. In some embodiments, the thickness of the electrode layer on the current collector is about 25 μm, about 30 μm, about 35 μm, about 40 μm, about 45 μm, about 50 μm, about 55 μm, about 60 μm, about 65 μm, about 70 μm, about 75 μm, about 80 μm, about 85 μm, about 90 μm, or about 95 μm.

[0172] In some embodiments, the surface density of the electrode layer on the current collector is about 1 mg / cm³. 2 Approximately 60 mg / cm 2 Approximately 1 mg / cm 2 Approximately 55 mg / cm 2 Approximately 1 mg / cm 2 Approximately 50 mg / cm 2 Approximately 1 mg / cm 2 Approximately 45 mg / cm 2 Approximately 1 mg / cm 2 Approximately 40 mg / cm 2 Approximately 1 mg / cm 2 Approximately 35 mg / cm 2 Approximately 1 mg / cm 2 Approximately 30 mg / cm 2 Approximately 1 mg / cm 2 Approximately 25 mg / cm 2 Approximately 10 mg / cm 2 Approximately 60 mg / cm 2 Approximately 10 mg / cm 2 Approximately 55 mg / cm 2 Approximately 10 mg / cm 2 Approximately 50 mg / cm 2 Approximately 10 mg / cm 2Approximately 45 mg / cm 2 Approximately 10 mg / cm 2 Approximately 40 mg / cm 2 Approximately 10 mg / cm 2 Approximately 35 mg / cm 2 Approximately 10 mg / cm 2 Approximately 30 mg / cm 2 Approximately 10 mg / cm 2 Approximately 25 mg / cm 2 Approximately 20 mg / cm 2 Approximately 60 mg / cm 2 Approximately 20 mg / cm 2 Approximately 55 mg / cm 2 Approximately 20 mg / cm 2 Approximately 50 mg / cm 2 Approximately 20 mg / cm 2 Approximately 45 mg / cm 2 Approximately 20 mg / cm 2 Approximately 40 mg / cm 2 Approximately 25 mg / cm 2 Approximately 60 mg / cm 2 Approximately 25 mg / cm 2 Approximately 55 mg / cm 2 Approximately 25 mg / cm 2 Approximately 50 mg / cm 2 Approximately 25 mg / cm 2 Approximately 45 mg / cm 2 Approximately 25 mg / cm 2 Approximately 40 mg / cm 2 Approximately 28 mg / cm³ 2 Approximately 60 mg / cm 2 Approximately 28 mg / cm³ 2 Approximately 55 mg / cm 2 Approximately 28 mg / cm³ 2 Approximately 50 mg / cm 2 Approximately 28 mg / cm³ 2 Approximately 45 mg / cm 2 Approximately 28 mg / cm³ 2 Approximately 40 mg / cm 2 Approximately 30 mg / cm 2 Approximately 60 mg / cm 2 Approximately 30 mg / cm 2 Approximately 55 mg / cm 2 Approximately 30 mg / cm 2 Approximately 50 mg / cm 2 Approximately 30 mg / cm2 Approximately 45 mg / cm 2 Approximately 30 mg / cm 2 Approximately 40 mg / cm 2 Approximately 35 mg / cm 2 Approximately 60 mg / cm 2 Approximately 35 mg / cm 2 Approximately 55 mg / cm 2 Approximately 35 mg / cm 2 Approximately 50 mg / cm 2 Approximately 35 mg / cm 2 Approximately 45 mg / cm 2 or about 30mg / cm 2 Approximately 40 mg / cm 2 .

[0173] In some embodiments, the surface density of the electrode layer on the current collector is about 1 mg / cm³. 2 or above, approximately 10 mg / cm³ 2 or above, approximately 20 mg / cm³ 2 or above, approximately 25 mg / cm³ 2 or above, approximately 28 mg / cm³ 2 or above, approximately 30 mg / cm³ 2 or above, approximately 31 mg / cm³ 2 or above, approximately 32 mg / cm³ 2 or above, approximately 33 mg / cm³ 2 or above, approximately 34 mg / cm³ 2 or above, approximately 35 mg / cm³ 2 or above, approximately 36 mg / cm³ 2 or above, approximately 37 mg / cm³ 2 or above, approximately 38 mg / cm³ 2 or above, approximately 39 mg / cm³ 2 or above or approximately 40 mg / cm 2 Or higher. In some embodiments, the surface density of the electrode layer on the current collector is about 60 mg / cm³. 2 or below, approximately 55 mg / cm³ 2 or below, approximately 50 mg / cm³ 2 or below, approximately 45 mg / cm³ 2 or below, approximately 44 mg / cm³ 2 or below, approximately 43 mg / cm³ 2 or below, approximately 42 mg / cm³ 2 or below, approximately 41 mg / cm³ 2 or below, approximately 40 mg / cm³ 2or below, approximately 39 mg / cm³ 2 or below, approximately 38 mg / cm³ 2 or below, approximately 37 mg / cm³ 2 or below, approximately 36 mg / cm³ 2 or below, approximately 35 mg / cm³ 2 or below, approximately 34 mg / cm³ 2 or below, approximately 33 mg / cm³ 2 or below, approximately 32 mg / cm³ 2 or below, approximately 31 mg / cm³ 2 or below or about 30 mg / cm 2 Or the following.

[0174] In some embodiments, a conductive layer may be coated onto the aluminum current collector to improve its current conductivity. In some embodiments, the conductive layer comprises a material selected from the group consisting of carbon, carbon black, graphite, expanded graphite, graphene, graphene nanosheets, carbon fibers, carbon nanofibers, graphitized carbon sheets, carbon nanotubes, carbon nanotubes, activated carbon, mesoporous carbon, and combinations thereof. In some embodiments, the conductive agent is not carbon, carbon black, graphite, expanded graphite, graphene, graphene nanosheets, carbon fibers, carbon nanofibers, graphitized carbon sheets, carbon nanotubes, carbon nanotubes, activated carbon, or mesoporous carbon.

[0175] In some embodiments, the thickness of the conductive layer is from about 0.5 μm to about 5.0 μm. The thickness of the conductive layer will affect the volume occupied by the current collector and the amount of electrode material in the battery, thereby affecting the battery capacity.

[0176] In some embodiments, the thickness of the conductive layer on the current collector is about 0.5 μm to about 4.5 μm, about 1.0 μm to about 4.0 μm, about 1.0 μm to about 3.5 μm, about 1.0 μm to about 3.0 μm, about 1.0 μm to about 2.5 μm, about 1.0 μm to about 2.0 μm, about 1.1 μm to about 2.0 μm, about 1.2 μm to about 2.0 μm, about 1.5 μm to about 2.0 μm, about 1.8 μm to about 2.0 μm, about 1.0 μm to about 1.8 μm, about 1.2 μm to about 1.8 μm, about 1.5 μm to about 1.8 μm, about 1.0 μm to about 1.5 μm, or about 1.2 μm to about 1.5 μm. In some embodiments, the thickness of the conductive layer on the current collector is less than 4.5 μm, less than 4.0 μm, less than 3.5 μm, less than 3.0 μm, less than 2.5 μm, less than 2.0 μm, less than 1.8 μm, less than 1.5 μm, or less than 1.2 μm. In some embodiments, the thickness of the conductive layer on the current collector is greater than 1.0 μm, greater than 1.2 μm, greater than 1.5 μm, greater than 1.8 μm, greater than 2.0 μm, greater than 2.5 μm, greater than 3.0 μm, or greater than 3.5 μm.

[0177] Furthermore, the electrodes prepared using this invention exhibit strong adhesion of the electrode layer to the current collector. Good peel strength between the electrode layer and the current collector is important because it prevents electrode peeling or separation, which would significantly affect the mechanical stability of the electrode and the cycle life of the battery. Therefore, the electrode should possess sufficient peel strength to withstand the harshness of the battery manufacturing process.

[0178] In some embodiments, the peel strength between the current collector and the electrode layer independently ranges from about 1.00 N / cm to about 7.00 N / cm, about 1.25 N / cm to about 7.00 N / cm, about 1.50 N / cm to about 7.00 N / cm, about 1.75 N / cm to about 7.00 N / cm, about 2.00 N / cm to about 7.00 N / cm, about 2.25 N / cm to about 7.00 N / cm, about 2.50 N / cm to about 7.00 N / cm, and about 2.75 N / cm to about 7.00 N / cm. The range is approximately 3.00 N / cm to approximately 7.00 N / cm, approximately 3.00 N / cm to approximately 6.75 N / cm, approximately 3.00 N / cm to approximately 6.50 N / cm, approximately 3.00 N / cm to approximately 6.25 N / cm, approximately 3.00 N / cm to approximately 6.00 N / cm, approximately 3.00 N / cm to approximately 5.75 N / cm, approximately 3.00 N / cm to approximately 5.50 N / cm, approximately 3.00 N / cm to approximately 5.25 N / cm, or approximately 3.00 N / cm to approximately 5.00 N / cm.

[0179] In some embodiments, the peel strength between the current collector and the anode or cathode electrode layer is independently about 1.00 N / cm or more, about 1.25 N / cm or more, about 1.50 N / cm or more, about 1.75 N / cm or more, about 2.00 N / cm or more, about 2.25 N / cm or more, about 2.50 N / cm or more, about 2.75 N / cm or more, about 3.00 N / cm or more, about 3.25 N / cm or more, about 3.5 N / cm or more, about 3.75 N / cm or more, about 4.00 N / cm or more, about 4.25 N / cm or more, or about 4.50 N / cm or more. In some embodiments, the peel strength between the current collector and the anode or cathode electrode layer is independently about 7.00 N / cm or less, about 6.75 N / cm or less, about 6.50 N / cm or less, about 6.25 N / cm or less, about 6.00 N / cm or less, about 5.75 N / cm or less, about 5.50 N / cm or less, about 5.25 N / cm or less, about 5.00 N / cm or less, about 4.75 N / cm or less, about 4.50 N / cm or less, about 4.25 N / cm or less, about 4.00 N / cm or less, about 3.75 N / cm or less, or about 3.50 N / cm or less.

[0180] The thickness of the current collector affects its volume in the battery, the amount of electrode active material required, and thus the battery capacity. In some embodiments, the thickness of the current collector is from about 5 μm to about 30 μm. In other embodiments, the thickness of the current collector is from about 5 μm to about 20 μm, from about 5 μm to about 15 μm, from about 10 μm to about 30 μm, from about 10 μm to about 25 μm, or from about 10 μm to about 20 μm.

[0181] In some embodiments, based on the total weight of the electrode layer, the additive constitutes a percentage of the electrode layer by weight of approximately 0.1% to approximately 5%, approximately 0.2% to approximately 5%, approximately 0.5% to approximately 5%, approximately 0.8% to approximately 5%, approximately 1% to approximately 5%, approximately 1.2% to approximately 5%, approximately 1.5% to approximately 5%, approximately 1.8% to approximately 5%, approximately 2% to approximately 5%, approximately 2.2% to approximately 5%, approximately 2.5% to approximately 5%, approximately 0.1% to approximately 4.5%, approximately 0.2% to approximately 4.5%, approximately 0.5% to approximately 4.5%, approximately 0.8% to approximately 4.5%, approximately 1% to approximately 4.5%, approximately 1.2% to approximately 4.5%, approximately 1.5% to approximately 4.5%, approximately 1.8% to approximately 4.5%, and approximately 2% to approximately 4% to approximately 4% to 5 ... 0.5%, about 0.1% to about 4%, about 0.2% to about 4%, about 0.5% to about 4%, about 0.8% to about 4%, about 1% to about 4%, about 1.2% to about 4%, about 1.5% to about 4%, about 1.8% to about 4%, about 2% to about 4%, about 0.1% to about 3.5%, about 0.2% to about 3.5%, about 0.5% to about 3.5%, about 0.8% to about 3.5%, about 1% to about 3.5%, about 1.2% to about 3.5%, about 1.5% to about 3.5%, about 0.1% to about 3%, about 0.2% to about 3%, about 0.5% to about 3%, about 0.8% to about 3%, about 1% to about 3%, about 0.5% to about 2%, or about 0.5% to about 1.5%.

[0182] In some embodiments, the additive constitutes a percentage of the electrode layer by weight of approximately 5% or less, approximately 4.5% or less, approximately 4% or less, approximately 3.5% or less, approximately 3% or less, approximately 2% or less, approximately 1.5% or less, approximately 1.4% or less, approximately 1.3% or less, approximately 1.2% or less, approximately 1.1% or less, approximately 1% or less, approximately 0.9% or less, approximately 0.8% or less, approximately 0.7% or less, approximately 0.6% or less, approximately 0.5% or less, approximately 0.4% or less, or approximately 0.3% or less. In some embodiments, the additive constitutes a percentage of the electrode layer by weight of approximately 0.1% or higher, approximately 0.2% or higher, approximately 0.3% or higher, approximately 0.4% or higher, approximately 0.5% or higher, approximately 0.6% or higher, approximately 0.7% or higher, approximately 0.8% or higher, approximately 0.9% or higher, approximately 1% or higher, approximately 1.1% or higher, approximately 1.2% or higher, approximately 1.3% or higher, approximately 1.4% or higher, approximately 1.5% or higher, approximately 2% or higher, approximately 2.5% or higher, approximately 3% or higher, or approximately 3.5% or higher.

[0183] In some embodiments, based on the total weight of the electrode layer, the content of the binder and the conductive agent in the electrode layer is independently about 0.5% to about 5%, about 0.5% to about 4.5%, about 0.5% to about 4%, about 0.5% to about 3.5%, about 0.5% to about 3%, about 1% to about 5%, about 1% to about 4.5%, about 1% to about 4%, about 1% to about 3.5%, about 1.5% to about 5%, about 1.5% to about 4.5%, or about 2% to about 5% by weight. In some embodiments, based on the total weight of the electrode layer, the content of the binder and the conductive agent in the electrode layer is independently about 0.5% or more, about 1% or more, about 1.5% or more, about 2% or more, about 2.5% or more, about 3% or more, or about 3.5% or more by weight. In some embodiments, the content of binder and conductive agent in the electrode layer is independently about 5% or less, about 4.5% or less, about 4% or less, about 3.5% or less, or about 3% or less by weight, based on the total weight of the electrode layer.

[0184] In some embodiments, based on the total weight of the electrode layer, the content of the electrode active material in the electrode layer is, by weight, about 40% to about 99%, about 40% to about 95%, about 40% to about 90%, about 40% to about 85%, about 40% to about 80%, about 40% to about 75%, about 40% to about 70%, about 50% to about 99%, about 50% to about 95%, about 50% to about 90%, about 50% to about 85%, about 50% to about 80%, about 50% to about 75%, about 50% to about 70%, about 60% to about 99%, about 60% to about 95%, about 60% to about 90%, about 60% to about 85%, about 60% to about 80%, about 60% to about 75%, about 70% to about 99%, about 70% to about 95%, about 70% to about 90%, about 70% to about 85%, about 75% to about 99%, about 75% to about 95%, about 75% to about 90%, about 75% to about 85%, about 80% to about 99%, about 80% to about 95%, or about 80% to about 90%. In some embodiments, based on the total weight of the electrode layer, the content of the electrode active material in the electrode layer is about 40%, about 50%, about 60%, about 70%, about 75%, about 80%, about 85%, about 90%, about 93%, or about 95% by weight.

[0185] In some embodiments, the content of the electrode active material in the electrode layer, based on the total weight of the electrode layer, is about 40% or more, about 45% or more, about 50% or more, about 55% or more, about 60% or more, about 65% or more, about 70% or more, about 75% or more, about 80% or more, about 85% or more, or about 90% or more by weight. In some embodiments, the content of the electrode active material in the electrode layer, based on the total weight of the electrode layer, is about 99% or less, about 95% or less, about 90% or less, about 85% or less, about 80% or less, about 75% or less, or about 70% or less by weight.

[0186] In some embodiments, the coating process can be performed by a doctor blade coater, an extrusion coater, a transfer coater, a spray coater, a roller coater, a gravure coater, an dip coater, or a curtain coater.

[0187] In battery fabrication, solvent evaporation is required to form dry, porous electrodes. After a homogenized electrode slurry is applied to a current collector, the coating on the current collector can be dried using a dryer to obtain the battery electrodes. Any dryer capable of drying the coating on the current collector is applicable herein. Some non-limiting examples of dryers include batch drying ovens, conveyor belt drying ovens, and microwave drying ovens. Some non-limiting examples of conveyor belt drying ovens include conveyor belt hot air drying ovens, conveyor belt resistance drying ovens, conveyor belt induction drying ovens, and conveyor belt microwave drying ovens.

[0188] In some embodiments, the conveyor drying oven for drying the coated film on the current collector includes one or more heating sections, each of which is independently temperature-controlled, and each heating section may include independently controlled heating zones. In some embodiments, each heating section independently includes one or more heating elements and a temperature control system connected to the heating elements, the two interacting to monitor and selectively control the temperature of each heating zone.

[0189] In some embodiments, the temperature of the coating film on the drying current collector can be from about 25°C to about 150°C. In some embodiments, the temperature of the coating film on the drying current collector can be about 25°C to about 140°C, about 25°C to about 130°C, about 25°C to about 120°C, about 25°C to about 110°C, about 25°C to about 100°C, about 25°C to about 90°C, about 25°C to about 80°C, about 25°C to about 70°C, about 30°C to about 90°C, about 30°C to about 80°C, about 30°C to about 70°C, about 40°C to about 90°C, about 40°C to about 80°C, about 40°C to about 70°C, about 50°C to about 90°C, about 50°C to about 80°C, about 60°C to about 150°C, about 60°C to about 140°C, about 60°C to about 130°C, about 60°C to about 120°C, about 60°C to about 110°C, about 60°C to about 100°C, about 60°C to about 90°C, or about 60°C to about 80°C.

[0190] In some embodiments, the temperature of the coating film on the drying current collector is about 150°C or lower, about 140°C or lower, about 130°C or lower, about 120°C or lower, about 110°C or lower, about 100°C or lower, about 90°C or lower, about 80°C or lower, or about 70°C or lower. In some embodiments, the temperature of the coating film on the drying current collector is about 100°C or higher, about 90°C or higher, about 80°C or higher, about 70°C or higher, about 60°C or higher, about 50°C or higher, about 40°C or higher, about 30°C or higher, or about 25°C or higher.

[0191] In some embodiments, the conveyor belt moves at speeds of about 1 m / min to about 120 m / min, about 1 m / min to about 100 m / min, about 1 m / min to about 50 m / min, about 10 m / min to about 120 m / min, about 10 m / min to about 100 m / min, about 10 m / min to about 50 m / min, about 25 m / min to about 120 m / min, about 25 m / min to about 100 m / min, about 25 m / min to about 50 m / min, about 50 m / min to about 120 m / min, or about 50 m / min to about 100 m / min.

[0192] Controlling the length and speed of the conveyor belt controls the drying time of the coated film. In some embodiments, the drying time of the coated film on the current collector can be about 1 minute to about 30 minutes, about 2 minutes to about 30 minutes, about 2 minutes to about 20 minutes, about 2 minutes to about 10 minutes, about 5 minutes to about 30 minutes, about 5 minutes to about 20 minutes, about 5 minutes to about 10 minutes, about 10 minutes to about 30 minutes, or about 10 minutes to about 20 minutes. In some embodiments, the drying time of the coated film on the current collector can be less than 5 minutes, less than 10 minutes, less than 15 minutes, less than 20 minutes, or less than 30 minutes. In some embodiments, the drying time of the coated film on the current collector can be about 5 minutes, about 10 minutes, about 15 minutes, about 20 minutes, or about 30 minutes.

[0193] Since the activity of the electrode active material is sufficient to chemically react with water, it is necessary to control the total processing time of method 100. In some embodiments, the total processing time is about 1 hour to about 8 hours, about 2 hours to about 6 hours, or about 2 hours to about 4 hours. In some embodiments, the total processing time is about 8 hours or less, about 6 hours or less, about 4 hours or less, or about 3 hours or less.

[0194] After the coating film on the current collector dries, it forms an electrode. In some embodiments, the electrode is mechanically compressed to increase the electrode density.

[0195] The method disclosed herein has the advantage of using aqueous solvents in the manufacturing process, which saves processing time and equipment, and improves safety by avoiding the need to handle or recycle hazardous organic solvents. Furthermore, costs are reduced by simplifying the overall process. Therefore, this method is particularly suitable for industrial production due to its low cost and ease of handling.

[0196] The development of aqueous binders for water-based electrode slurries has improved slurry stability without compromising battery performance (e.g., cycle life and capacity). By adding additives to water-based electrode slurries, electrodes prepared according to the present invention exhibit excellent flexibility even at high surface densities. Batteries containing the positive electrode prepared according to the present invention demonstrate high cycle stability. Furthermore, the lower drying temperature and shorter drying time of the coating significantly improve battery performance.

[0197] This document also provides a set of electrode assemblies comprising electrodes prepared by the methods described above. The electrode assembly includes at least one cathode, at least one anode, and at least one diaphragm disposed between the cathode and the anode.

[0198] In some embodiments, the electrode assembly is dried after assembly to reduce its water content. In other embodiments, at least one component of the electrode assembly is dried before assembling the electrode assembly. In some embodiments, at least one component is pre-dried before assembling the electrode assembly. In some embodiments, the diaphragm is pre-dried before being assembled into the electrode assembly.

[0199] It is not necessary to dry the membrane to a very low moisture content. The remaining moisture content in the pre-dried membrane can be further reduced by subsequent drying steps. In some embodiments, the water content in the pre-dried diaphragm is, by weight, about 50 ppm to about 800 ppm, about 50 ppm to about 700 ppm, about 50 ppm to about 600 ppm, about 50 ppm to about 500 ppm, about 50 ppm to about 400 ppm, about 50 ppm to about 300 ppm, about 50 ppm to about 200 ppm, about 50 ppm to about 100 ppm, about 100 ppm to about 500 ppm, about 100 ppm to about 400 ppm, about 100 ppm to about 300 ppm, about 100 ppm to about 200 ppm, about 200 ppm to about 500 ppm, about 200 ppm to about 400 ppm, about 300 ppm to about 800 ppm, about 300 ppm to about 600 ppm, about 300 ppm to about 500 ppm, about 300 ppm to about 400 ppm, about 400 ppm to about 800 ppm, or about 400 ppm to about 500 ppm. In some implementations, the water content in the pre-dried diaphragm is less than 500 ppm, less than 400 ppm, less than 300 ppm, less than 200 ppm, less than 100 ppm, or less than 50 ppm by weight, based on the total weight of the pre-dried diaphragm.

[0200] In some embodiments, the water content in the dried electrode assembly may be, by weight, about 20 ppm to about 350 ppm, about 20 ppm to about 300 ppm, about 20 ppm to about 250 ppm, about 20 ppm to about 200 ppm, about 20 ppm to about 100 ppm, about 20 ppm to about 50 ppm, about 50 ppm to about 350 ppm, about 50 ppm to about 250 ppm, about 50 ppm to about 150 ppm, about 100 ppm to about 350 ppm, about 100 ppm to about 300 ppm, about 100 ppm to about 250 ppm, about 100 ppm to about 200 ppm, about 100 ppm to about 150 ppm, about 150 ppm to about 350 ppm, about 150 ppm to about 300 ppm, about 150 ppm to about 250 ppm, about 150 ppm to about 200 ppm, about 200 ppm to about 350 ppm, about 250 ppm to about 350 ppm, or about 300 ppm to about 350 ppm.

[0201] The following embodiments are provided to illustrate implementations of the invention, but are not intended to limit the invention to the specific embodiments listed. Unless otherwise stated, all parts and percentages are by weight. All values ​​are approximate. When numerical ranges are given, it should be understood that implementations outside the stated ranges still fall within the scope of the invention. Specific details described in the various embodiments should not be construed as essential features of the invention.

[0202] Example

[0203] The pH value of the binder composition was measured at room temperature using an electrode-type pH meter (ION 2700, Eutech Instruments). The viscosity of the slurry was measured at room temperature using a rotational viscometer (NDJ-5S, JT Electronics Technology Co., Ltd., Shanghai, China) at a rotational speed of 12 rpm using a No. 3 rotor.

[0204] The peel strength of the dried electrode layer was measured using a tensile tester (DZ-106A, from Dongguan Zonhow Test Equipment Co., Ltd., China). This test measures the average force required to peel the electrode layer from the current collector at a 180° angle for each 18mm wide test sample. An 18mm wide strip of adhesive tape (3M; USA; Model 810) was adhered to the surface of the cathode electrode layer. The cathode strip was clamped in the tester, and the tape was folded back 180° and placed in a movable jaw, then pulled at a peel speed of 200 mm / min at room temperature. The maximum peel force measured was taken as the peel strength. The measurement was repeated three times and the average value was taken.

[0205] According to the Chinese standard GB / T 1731-93 for determining membrane flexibility, the flexibility of the electrode is measured using specialized equipment with fixed rods of various diameters or radii of curvature. The cathode strip, prepared by coating aluminum foil with electrode paste, is placed in an electric blast drying oven for 15-30 minutes at a constant temperature, and then placed in a constant temperature and humidity environment for 30-60 minutes. This ensures that the cathode meets the flexibility test requirements of Chinese standard GB 1727-92. The cathode strip is mechanically bent around a rod with a constant force for 2-3 seconds, then removed and examined under a 4x microscope for defects such as peeling, cracking, or breakage. The electrode flexibility is defined as the minimum diameter (or an equivalent based on the radius of curvature) Ф of the rod in which the electrode can be bent without defects, with the diameter unit being mm.

[0206] The water content in the electrode assembly and diaphragm was measured using Karl-Fischer titration. The electrode assembly or diaphragm was cut into 1cm × 1cm pieces in an argon-filled glove box. Each 1cm × 1cm piece of the cut electrode assembly or diaphragm was weighed in a sample vial. The weighed electrode assembly or diaphragm was then added to the titration vessel and Karl-Fischer titration was performed using a Karl-Fischer coulometric moisture analyzer (831KF coulometer, Metrohm, Switzerland). The measurement was repeated three times, and the average value was taken.

[0207] Example 1

[0208] A) Preparation of adhesive composition

[0209] Add 18.15 g of sodium hydroxide (NaOH) to a round-bottom flask containing 380 g of distilled water. Stir the mixture at 80 rpm for 30 minutes to obtain the first binder synthesis suspension.

[0210] Add 36.04 g of acrylic acid to the first suspension. Stir the mixture further at 80 rpm for 30 minutes to obtain the second binder synthesis suspension.

[0211] 19.04 g of acrylamide was dissolved in 10 g of deionized water to form an acrylamide solution. Then, all of the acrylamide solution was added to the second suspension. The mixture was further heated to 55°C and stirred at 80 rpm for 45 minutes to obtain a third binder synthesis suspension.

[0212] 12.92 g of acrylonitrile was added to the third suspension. The mixture was further stirred at 80 rpm for 10 minutes to obtain the fourth binder synthesis suspension.

[0213] Further, 0.015 g of water-soluble free radical initiator (ammonium persulfate, APS; from Aladdin Industrial Co., Ltd., China) was dissolved in 3 g of deionized water, and 0.0075 g of reducing agent (sodium bisulfite; from Tianjin Damao Chemical Reagent Factory, China) was dissolved in 1.5 g of deionized water. All APS solutions and all sodium bisulfite solutions were added dropwise to the fourth suspension. The mixture was stirred at 200 rpm for 24 hours at 55°C to obtain the fifth binder synthesis suspension.

[0214] After the reaction was complete, the temperature of the fifth binder synthesis suspension was lowered to 25°C. 3.72 g of NaOH was dissolved in 400 g of deionized water. Then, all of this sodium hydroxide solution was slowly added to the fifth binder synthesis suspension to adjust the pH to 7.3 to form the sixth binder synthesis suspension. The sixth binder synthesis suspension was filtered through a 200 μm nylon mesh to form the binder material. The solids content of the binder composition was 9.00 wt.%. The components of the binder composition of Example 1 and their respective proportions are shown in Table 1 below.

[0215] B) Preparation of the positive electrode

[0216] 0.090 g of an additive conforming to general formula (1), wherein the values ​​of a and c are each 7 and the value of b is 21, and 7.48 g of the above-described binder composition were added to 16.9 g of deionized water, while stirring using a top-mounted stirrer (R20, IKA) to prepare a first suspension. After addition, the first suspension was further stirred at 1200 rpm at 25°C for approximately 30 minutes.

[0217] Subsequently, 0.675 g of conductive agent (Super P; obtained from Timcal Ltd, Bodio, Switzerland) was added to the first suspension to prepare the second suspension. After addition, the second suspension was further stirred at 25°C for approximately 30 minutes.

[0218] Subsequently, 21.0 g of LiFePO4 (LFP; obtained from Shenzhen Dynanonic Co., Ltd., China) was added to the second suspension at 25 °C while stirring with a top-mounted stirrer to prepare a third suspension. The third suspension was then degassed at approximately 10 kPa for 1 hour. It was then further stirred at 1200 rpm at 25 °C for approximately 60 minutes to form a homogenized electrode slurry. The binder accounted for 3 wt.% of the total solids content in the slurry. The particle size D50 of the LFP was 1 μm. The viscosity of the homogenized slurry was 4260 mPa·s.

[0219] A homogenized electrode slurry was coated onto one side of an aluminum foil serving as a current collector, with a thickness of 16 μm, using a blade coater with a gap width of 100 μm. The coated slurry film on the aluminum foil was dried at 50°C for approximately 6 minutes to form a cathode electrode layer. The electrode was then pressed to reduce the thickness of the cathode electrode layer on the current collector to 85 μm. The flexibility and surface density of the cathode made using the slurry composition of Example 1 were measured and are shown in Table 2 below. Figure 2 The image shows the dried coating slurry, taken shortly after the coating had completely dried on the current collector. The peel strength of the dried electrode layer was 4.31 N / cm.

[0220] C) Preparation of the negative electrode

[0221] A negative electrode slurry was prepared by mixing 92 wt.% hard carbon (BTR New Energy Materials Co., Ltd., Shenzhen, Guangdong, China), 1 wt.% carboxymethyl cellulose (CMC, BSH-12, DKS Co., Ltd., Japan) as a binder, 3 wt.% SBR (AL-2001, NIPPON A&LINC., Japan), and 4 wt.% carbon black as a conductive agent in deionized water. The anode slurry had a solids content of 50 wt.%. The slurry was coated onto one side of a copper foil with a thickness of 8 μm using a doctor blade coater with a gap width of approximately 95 μm. The coating on the copper foil was dried at approximately 50°C for 2.4 minutes using a hot air dryer to obtain the negative electrode. The electrode was then pressed to reduce the coating thickness to 55 μm and the surface density to 17 mg / cm³. 2 .

[0222] D) Assembly of button batteries

[0223] CR2032 button-type Li batteries were assembled in an argon-filled glove box. Coated cathode and anode plates were cut into disc-shaped positive and negative electrodes, and then assembled into an electrode assembly by alternately stacking the cathode and anode plates and placing them in a CR2032 stainless steel housing. The cathode and anode plates were kept separate by a separator. The separator was a ceramic-coated microporous membrane made of polyethylene (Hebei Gellec New Energy Science & Technology Co., Ltd., China), with a thickness of approximately 16 μm. The electrode assembly was then dried in a box-type resistance furnace (DZF-6020, from Shenzhen Kejing Xingguang Technology Co., Ltd., China) under vacuum at 90°C for approximately 16 hours. The moisture content of the dried separator and electrode assembly was 200 ppm and 300 ppm, respectively.

[0224] In a high-purity argon atmosphere with humidity and oxygen content both less than 3 ppm, the electrolyte is injected into the housing containing the packaged electrodes. The electrolyte is a solution containing LiPF6 (1M) in a 1:1:1 volume ratio mixture of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC). After electrolyte injection, the button cell is vacuum-sealed and then mechanically pressed using a standard circular stamping tool.

[0225] E) Electrochemical Measurement

[0226] The button cell was analyzed in constant current mode using a multichannel battery tester (BTS-4008-5V 10mA, from Xinwei Electronics Co., Ltd., China). After one cycle at C / 20, it was charged and discharged at C / 2. The discharge capacity was obtained by charge / discharge cycling the battery at 25°C with a current density between 2.0 and 3.65V at C / 2. The electrochemical performance of the button cell of Example 1 was measured and is shown in Table 2 below.

[0227] Examples 2-4

[0228] The positive electrode was prepared in the same manner as in Example 1, except that the values ​​of additives a, b, and c were changed as shown in Table 1 below.

[0229] Example 5

[0230] The positive electrode was prepared in the same manner as in Example 3, except that the amount of additive added to the first suspension was 0.067 g.

[0231] Example 6

[0232] The positive electrode was prepared in the same manner as in Example 3, except that the amounts of binder composition and additives added to the first suspension were 7.57 g and 0.364 g, respectively.

[0233] Examples 7-11:

[0234] The positive electrode was prepared in the same manner as in Example 3, except that the binder composition was synthesized as described below to achieve the monomer ratios shown in Table 1 below.

[0235] Adhesive composition of Example 7

[0236] The binder compositions were prepared in the same manner as in Example 1, except that 28.70 g of NaOH was added when preparing the first binder synthesis suspension, 56.21 g of acrylic acid was added when preparing the second binder synthesis suspension, 4.27 g of acrylamide was added when preparing the third binder synthesis suspension, and 8.49 g of acrylonitrile was added when preparing the fourth binder synthesis suspension.

[0237] Adhesive composition of Example 8

[0238] The binder compositions were prepared in the same manner as in Example 1, except that 18.37 g of NaOH was added when preparing the first binder synthesis suspension, 36.44 g of acrylic acid was added when preparing the second binder synthesis suspension, 15.82 g of acrylamide was added when preparing the third binder synthesis suspension, and 15.03 g of acrylonitrile was added when preparing the fourth binder synthesis suspension.

[0239] Adhesive composition of Example 9

[0240] The binder compositions were prepared in the same manner as in Example 1, except that 16.93 g of NaOH was added when preparing the first binder synthesis suspension, 33.15 g of acrylic acid was added when preparing the second binder synthesis suspension, 23.46 g of acrylamide was added when preparing the third binder synthesis suspension, and 11.14 g of acrylonitrile was added when preparing the fourth binder synthesis suspension.

[0241] Adhesive composition of Example 10

[0242] The binder compositions were prepared in the same manner as in Example 1, except that 11.78 g of NaOH was added when preparing the first binder synthesis suspension, 23.06 g of acrylic acid was added when preparing the second binder synthesis suspension, 6.40 g of acrylamide was added when preparing the third binder synthesis suspension, and 31.31 g of acrylonitrile was added when preparing the fourth binder synthesis suspension.

[0243] Adhesive composition of Example 11

[0244] The binder compositions were prepared in the same manner as in Example 1, except that 14.72 g of NaOH was added when preparing the first binder synthesis suspension, 28.82 g of acrylic acid was added when preparing the second binder synthesis suspension, 16.35 g of acrylamide was added when preparing the third binder synthesis suspension, and 19.63 g of acrylonitrile was added when preparing the fourth binder synthesis suspension.

[0245] Comparative Example 1

[0246] The positive electrode was prepared in the same manner as in Example 1, except that no additives were added to the first suspension.

[0247] Comparative Examples 2-3

[0248] The positive electrode was prepared in the same manner as in Example 1, except that the values ​​of additives a, b, and c were changed as shown in Table 1 below.

[0249] Comparative Examples 4-9

[0250] The positive electrode was prepared in the same manner as in Example 3, except that the binder composition was synthesized as described below to achieve the monomer ratios shown in Table 1 below.

[0251] Adhesive composition of Comparative Example 4

[0252] The adhesive compositions were prepared in the same manner as in Example 1, except that 7.45 g of NaOH was added when preparing the first adhesive synthesis suspension, 16.77 g of acrylic acid was added when preparing the second adhesive synthesis suspension, 7.19 g of acrylamide was added when preparing the third adhesive synthesis suspension, and 35.95 g of acrylonitrile was added when preparing the fourth adhesive synthesis suspension.

[0253] Adhesive composition of Comparative Example 5

[0254] The binder compositions were prepared in the same manner as in Example 1, except that 30.51 g of NaOH was added when preparing the first binder synthesis suspension, 58.31 g of acrylic acid was added when preparing the second binder synthesis suspension, no acrylamide was added when preparing the third binder synthesis suspension, and 10.73 g of acrylonitrile was added when preparing the fourth binder synthesis suspension.

[0255] Adhesive composition of Comparative Example 6

[0256] The binder compositions were prepared in the same manner as in Example 1, except that 24.44 g of NaOH was added when preparing the first binder synthesis suspension, 47.38 g of acrylic acid was added when preparing the second binder synthesis suspension, 25.16 g of acrylamide was added when preparing the third binder synthesis suspension, and no acrylonitrile was added when preparing the fourth binder synthesis suspension.

[0257] Adhesive composition of Comparative Example 7

[0258] The binder compositions were prepared in the same manner as in Example 1, except that 14.72 g of NaOH was added when preparing the first binder synthesis suspension, 28.83 g of acrylic acid was added when preparing the second binder synthesis suspension, 31.99 g of acrylamide was added when preparing the third binder synthesis suspension, and 8.05 g of acrylonitrile was added when preparing the fourth binder synthesis suspension.

[0259] Available Figure 3 See the image of the dried coating slurry applied to the positive electrode in Comparative Example 4. It was taken shortly after the coating on the current collector had completely dried.

[0260] Adhesive composition of Comparative Example 8

[0261] The binder compositions were prepared in the same manner as in Example 1, except that 4.78 g of NaOH was added when preparing the first binder synthesis suspension, 9.37 g of acrylic acid was added when preparing the second binder synthesis suspension, 21.32 g of acrylamide was added when preparing the third binder synthesis suspension, and 30.26 g of acrylonitrile was added when preparing the fourth binder synthesis suspension.

[0262] Comparative Examples 9-10

[0263] The positive electrode was prepared in the same manner as in Example 1, except that the additive was replaced with the same weight of Triton. TM X-100 (a nonionic surfactant) and triethyl citrate (an ionic surfactant).

[0264] Preparation of negative electrodes in Examples 2-11 and Comparative Examples 1-10

[0265] The negative electrodes of Examples 2-11 and Comparative Examples 1-10 were prepared in the same manner as in Example 1.

[0266] Assembly of button batteries in Examples 2-11 and Comparative Examples 1-10

[0267] The button batteries of Examples 2-11 and Comparative Examples 1-10 were assembled in the same manner as in Example 1.

[0268] Electrochemical measurements of Examples 2-11 and Comparative Examples 1-10

[0269] The electrochemical performance of the button batteries of Examples 2-11 and Comparative Examples 1-10 was measured using the same method as in Example 1, and the test results are shown in Table 2 below.

[0270] Although the invention has been described in conjunction with a limited number of embodiments, specific features of one embodiment should not limit other embodiments of the invention. In some embodiments, the method may include multiple steps not mentioned herein. In other embodiments, the method does not include or substantially does not contain any steps not listed herein. Variations and modifications based on the described embodiments exist. The appended claims are intended to cover all such variations and modifications that fall within the scope of the invention.

[0271] Table 1

[0272]

[0273] Table 2

[0274]

[0275] * Due to insufficient electrode flexibility, a testable battery could not be manufactured.

[0276] #Failed to manufacture testable electrodes.

Claims

1. An electrode for a secondary battery, comprising a current collector and an electrode layer coated on one or more surfaces of the current collector, wherein the electrode layer comprises an electrode active material, a binder, and an additive, wherein the additive conforms to general formula (1): (1) Wherein a and c are independently 3 to 12, and b is 17 to 70, wherein the adhesive comprises a copolymer, wherein the copolymer comprises one or more hydrophilic structural units and one or more hydrophobic structural units, wherein the hydrophilic structural units are derived from monomers containing carboxylic acids and monomers containing amides, wherein the hydrophobic structural units are derived from monomers containing nitrile groups, wherein, based on the total molar number of monomer units in the adhesive, the proportion of structural units derived from carboxylic acid monomers is 30-80%, the proportion of structural units derived from amide monomers is 5-35%, and the proportion of structural units derived from nitrile monomers is 15-60%.

2. The electrode according to claim 1, wherein the additive has a number average molecular weight of 1,000 to 5,000 and a hydrophilic-lipophilic balance value of 3 to 13.

3. The electrode according to claim 1, wherein a and c are the same.

4. The electrode according to claim 1, wherein the proportions of repeating units α and γ are each independently 1% to 40% by weight based on the total weight of the additive, wherein the repeating units α and γ correspond to a and c in general formula (1).

5. The electrode according to claim 1, wherein the thickness of the electrode layer on the current collector is from 5 μm to 120 μm, and wherein the surface density of the electrode layer on the current collector is 1 mg / cm³. 2 Up to 60 mg / cm 2 .

6. The electrode according to claim 1, wherein the electrode active material is selected from Li 1+x Ni a Mn b Co c Al (1-a-b-c) The cathode active material of O2, wherein -0.2≤x≤0.2, 0≤a<1, 0≤b<1, 0≤c<1, and a+b+c≤1.

7. The electrode according to claim 6, wherein the electrode active material is selected from the group consisting of LiNi 0.33 Mn 0.33 Co 0.33 O2, LiNi 0.4 Mn 0.4 Co 0.2 O2, LiNi 0.5 Mn 0.3 Co 0.2 O2, LiNi 0.6 Mn 0.2 Co 0.2 O2, LiNi 0.7 Mn 0.15 Co 0.15 O2, LiNi 0.7 Mn 0.1 Co 0.2 O2, LiNi 0.8 Mn 0.1 Co 0.1 O2, LiNi 0.92 Mn 0.04 Co 0.04 O2, LiNi 0.8 Co 0.15 Al 0.05 O2, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, Li2MnO3, LiFePO4, LiCoPO4, LiNiPO4, LiMnPO4, LiMnFePO4, LiMn d Fe (1-d) PO4, dLi2MnO3·(1 - d)LiMO2, LiNi e Mn f O4, Li3V2(PO4)3, LiVPO4F, Li2MSiO4 and combinations thereof, where 0 < d < 1, 0.1 ≤ e ≤ 0.9, 0 ≤ f ≤ 2, and M is selected from the group consisting of Fe, Co, Mn, Ni and combinations thereof.

8. The electrode according to claim 1, wherein the electrode active material is a cathode active material comprising or being itself a core-shell composite material comprising a core and a shell, wherein the core and shell independently comprise materials selected from Li. 1+x Ni a Mn b Co c Al (1-a-b-c) Lithium transition metal oxides of O2, wherein -0.2≤x≤0.2, 0≤a<1, 0≤b<1, 0≤c<1 and a+b+c≤1.

9. The electrode according to claim 8, wherein the lithium transition metal oxide is selected from LiCoO2, LiNiO2, LiMnO2, LiMn2O4, Li2MnO3, LiFePO4, LiCrO2, Li4Ti5O 12 , LiV2O5, LiTiS2, LiMoS2, LiCo a Ni b O2, LiMn a Ni b Groups consisting of O2 and its combinations.

10. The electrode according to claim 1, wherein the electrode active material is selected from natural graphite particles, synthetic graphite particles, Sn (tin) particles, Li4Ti5O 12 Anode active materials consisting of particles, Si (silicon) particles, Si-C composite particles and combinations thereof.

11. The electrode according to claim 1, wherein the number-average molecular weight of the additive is 1800 to 2800.

12. The electrode according to claim 1, wherein b is 20 to 40.

13. The electrode according to claim 1, further comprising a conductive agent composed of carbon.

14. The electrode according to claim 13, wherein the carbon is selected from the group consisting of carbon black, graphite, expanded graphite, graphene, carbon fiber, graphitized carbon sheet, carbon nanotube, activated carbon, mesoporous carbon, and combinations thereof.

15. The electrode according to claim 14, wherein the graphene is graphene nanosheet, the carbon fiber is carbon nanofiber, and the carbon nanotube is carbon nanotube.

16. The electrode of claim 1, wherein the additive constitutes 0.1% to 5% by weight of the electrode layer based on the total weight of the electrode layer.

17. The electrode of claim 1, further comprising a conductive agent, wherein the content of the binder and the conductive agent in the electrode layer is independently from 0.5% to 5% by weight, based on the total weight of the electrode layer.

18. An electrode slurry for a secondary battery, comprising an electrode active material, a binder, an additive, and a solvent, wherein the additive conforms to general formula (1): (1) Wherein a and c are independently 3 to 12, and b is 17 to 70, wherein the adhesive comprises a copolymer, wherein the copolymer comprises one or more hydrophilic structural units and one or more hydrophobic structural units, wherein the hydrophilic structural units are derived from monomers containing carboxylic acids and monomers containing amides, wherein the hydrophobic structural units are derived from monomers containing nitrile groups, wherein, based on the total molar number of monomer units in the adhesive, the proportion of structural units derived from carboxylic acid monomers is 30-80%, the proportion of structural units derived from amide monomers is 5-35%, and the proportion of structural units derived from nitrile monomers is 15-60%.

19. The electrode paste according to claim 18, wherein the solvent is water.

20. The electrode slurry of claim 18, wherein the additive accounts for 0.1% to 5% by weight of the electrode slurry based on the total weight of the solids content of the electrode slurry.

21. The electrode slurry of claim 18, wherein the content of the electrode active material in the electrode slurry is 20% to 80% by weight, based on the total weight of the electrode slurry.

22. A secondary battery comprising the electrode as described in any one of claims 1-17.

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