Conductive agent composition, positive electrode sheet, battery, and electric device

Abstract

The application relates to the technical field of batteries, and specifically discloses a conductive agent composition, a positive plate, a battery and a power utilization device, wherein the conductive agent composition comprises: a first conductive agent, the first conductive agent comprising a sheet-shaped conductive agent; and a second conductive agent, the second conductive agent comprising at least one of a spherical conductive agent and a tubular conductive agent. The compaction density of the positive plate prepared by using the conductive agent composition is improved, and the battery adopting the positive plate has excellent conductive performance.

Description

Technical Field

[0001] This application belongs to the field of battery technology, specifically relating to a conductive agent composition, a positive electrode sheet, a battery, and an electrical device. Background Technology

[0002] With the continuous development of rechargeable battery technology, higher requirements are being placed on battery materials. However, the low compaction density of rechargeable batteries remains a problem restricting their large-scale application. In related technologies, inventors have improved the overall performance of rechargeable batteries by modifying the positive electrode active material, but problems such as poor stability, complex reactants, high technical difficulty, or high cost still exist. Therefore, improving compaction density remains a challenge for rechargeable batteries. Summary of the Invention

[0003] This application is based on the inventor's discoveries and understanding of the following facts and problems:

[0004] Rechargeable batteries are among the most promising power batteries. However, low compaction density has always been a problem limiting their large-scale application. To address this issue, researchers have made a series of improvements. For example, some researchers have improved the overall performance of rechargeable batteries by controlling the particle size, specific surface area, and coating amount of the cathode active material; others have improved the compaction density of rechargeable batteries by designing single-crystal layered and mixed layered oxide cathode materials; still others have improved the compaction density of cathode sheets by controlling the preparation process parameters of cathode active materials.

[0005] Although the above-mentioned studies on modifying the active material can improve the compaction density of secondary batteries to some extent, the following problems still exist:

[0006] (1) It has poor robustness, and there will be large fluctuations between different batches of active materials;

[0007] (2) During the preparation of active materials, the reactant system is relatively complex. Incomplete reactions may generate some byproducts, which may affect the subsequent battery performance.

[0008] (3) All of these methods involve modifying the main material. However, changes in the physicochemical properties of the main material can significantly affect the overall properties of the battery. Improving compaction without degrading other performance characteristics is technically very difficult. In addition, considering the large demand for main materials in practical applications, the stability of the main materials prepared by the above methods between batches needs further verification, so their feasibility is questionable. Changes in the main material may cause incompatibility with conductive agents, binders, electrolytes, etc., which may require further changes in the types and contents of other auxiliary materials, resulting in a significant increase in cost.

[0009] In summary, although there are some modification methods for the active main material to improve the compaction density of secondary batteries, these methods have low feasibility and high cost. Therefore, this application addresses the above problems by taking into account feasibility and cost, and designs a new conductive agent to improve the compaction density of the cathode material. It is applicable to secondary batteries such as sodium-ion batteries and lithium-ion batteries.

[0010] This application aims to at least partially solve one of the technical problems in the related art. To this end, this application proposes a conductive agent composition with high compaction density and excellent electrical conductivity, a positive electrode sheet, a battery, and an electrical device.

[0011] The first aspect of this application discloses a conductive agent composition, comprising: a first conductive agent, the first conductive agent comprising a sheet-like conductive agent; and a second conductive agent, the second conductive agent comprising at least one of a spherical conductive agent and a tubular conductive agent. The positive electrode sheet prepared using this conductive agent composition can achieve a tight bond between the conductive agent and the active material, achieving a dense gradation effect, improving the compaction density of the positive electrode sheet while ensuring its excellent conductivity.

[0012] In some embodiments, the conductive agent composition includes the sheet-like conductive agent, the spherical conductive agent, and the tubular conductive agent. Therefore, the synergistic effect of the three shapes of conductive agents is better, resulting in a better improvement in the compaction density of the positive electrode sheet.

[0013] In some embodiments, the specific surface area of ​​the spherical conductive agent is 60 m². 2 / g~120m 2 / g, and / or, the oil absorption value of the spherical conductive agent is ≥200mL / 100g. This facilitates the adsorption of electrolytes and improves ionic conductivity.

[0014] In some embodiments, the sheet-like conductive agent includes a small-diameter conductive agent and a large-diameter conductive agent. The sheet diameter L1 of the small-diameter conductive agent satisfies 0.1 μm ≤ L1 < 5 μm, and the sheet diameter L2 of the large-diameter conductive agent satisfies 5 μm ≤ L2 ≤ 20 μm. This is beneficial for improving the conductivity of the positive electrode using this conductive agent composition, reducing the amount of conductive agent used, and increasing the energy density of the battery.

[0015] In some embodiments, the tubular conductive agent includes a high aspect ratio conductive agent and a low aspect ratio conductive agent. The aspect ratio N1 of the low aspect ratio conductive agent satisfies 100 ≤ N1 < 1000, and the aspect ratio N2 of the high aspect ratio conductive agent satisfies 1000 ≤ N2 ≤ 50000. This results in better gradation, which is more conducive to increasing the compaction density of the positive electrode sheet, thereby increasing the energy density of the conductive agent composition.

[0016] In some embodiments, the aspect ratio N2 of the high aspect ratio conductive agent is ≥ 10:1 to the aspect ratio N1 of the low aspect ratio conductive agent. This is beneficial for improving the energy density and cycle life of batteries using this conductive agent composition.

[0017] In some embodiments, based on the total mass of the conductive agent composition, the mass percentages of the sheet-like conductive agent, the spherical conductive agent, and the tubular conductive agent are a, b, and c, respectively, where a, b, and c satisfy: 1>a>0, 1>b≥0, 1>c≥0, and |b+c|≥a≥|bc|, wherein b and c are not simultaneously 0.

[0018] In some embodiments, in the conductive agent composition, a, b, and c satisfy: 0.5 ≥ a ≥ 0.2, 0.5 ≥ b ≥ 0, and 0.5 ≥ c ≥ 0.

[0019] In some embodiments, the sheet-like conductive agent includes at least one of graphene and graphite flakes; and / or the spherical conductive agent includes carbon black; and / or the tubular conductive agent includes at least one of carbon nanotubes and conductive carbon fibers.

[0020] A second aspect of this application discloses a positive electrode sheet comprising the conductive agent composition described in the first aspect. Consequently, the positive electrode sheet exhibits high compaction density and good electrical conductivity.

[0021] In some embodiments, the positive electrode sheet further includes a positive electrode active material and a binder, wherein the mass ratio of the conductive agent composition, the binder, and the positive electrode active material is 0.01–0.3:0.005–0.1:1. With the above material ratio, the positive electrode sheet exhibits high compaction density, high capacity, and good conductivity.

[0022] In some embodiments, the positive electrode further includes a dispersant, said dispersant comprising at least one of polyvinylpyrrolidone, sodium lauryl sulfate, sodium lauryl sulfonate, sodium dodecylbenzene sulfonate, polyacrylamide, and sodium carboxymethyl cellulose. This allows for better dispersion of the conductive agent, resulting in a positive electrode with good uniformity and superior performance.

[0023] In some embodiments, the Dv50 particle size of the positive electrode active material is 3 μm to 7 μm. This particle size range allows for better interaction with the conductive agent composition, resulting in a better effect on improving the compaction density of the positive electrode sheet.

[0024] In some embodiments, the particle size of the positive electrode active material (Dv50) minus the particle size of the small-diameter conductive agent is ≤1 μm. Therefore, with conductive agents and positive electrode active materials of similar particle sizes, the conductive agent can fully utilize its ductility and slip properties during the rolling process, and by rationally utilizing the gaps between the positive electrode active material particles, a higher compaction density can be achieved.

[0025] In some embodiments, the positive electrode active material includes a sodium-ion battery positive electrode material or a lithium-ion battery positive electrode material; the sodium-ion battery positive electrode material includes at least one of transition metal oxides, polyanionic compounds, organic polymers, and Prussian blue materials; the lithium-ion battery positive electrode material includes at least one of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium nickel manganese oxide, lithium nickel oxide, lithium manganese oxide, lithium cobalt oxide, lithium iron phosphate, and lithium manganese iron phosphate.

[0026] A third aspect of this application discloses a battery comprising the conductive agent composition described in the first aspect or the positive electrode sheet described in the second aspect. Therefore, the battery exhibits high compaction density and good electrical conductivity.

[0027] The fourth aspect of this application discloses an electrical device including the battery described in the third aspect. Therefore, this electrical device has better overall performance and a longer service life.

[0028] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0029] Figure 1 This is a SEM image of the positive electrode sheet of Embodiment 1 of this application.

[0030] Figure 2 This is a SEM image of the positive electrode of Comparative Example 1 of this application. Detailed Implementation

[0031] The embodiments of this application are described in detail below, with examples of these embodiments illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0032] In a first aspect of this application, a conductive agent composition is proposed, comprising: a first conductive agent, the first conductive agent comprising a sheet-like conductive agent; and a second conductive agent, the second conductive agent comprising at least one of a spherical conductive agent and a tubular conductive agent. The positive electrode sheet prepared using this conductive agent composition can improve the compaction density of the positive electrode sheet while maintaining its excellent conductivity. Specifically, the sheet-like conductive agent is dispersed between the main material particles. During the rolling process, due to the slippage of the sheet-like conductive agent, a certain frictional force is generated between the main material particles and the sheet-like conductive agent, allowing some of the main material particles to fill the gaps, thereby achieving the effect of increasing the compaction density. However, considering that although the sheet-like conductive agent can construct a long-range conductive network, the sheet-like structure may lead to islands in the main material, resulting in more gaps between the main material particles, making it impossible to effectively build a conductive network between the main material particles, resulting in poor conductivity. At the same time, spherical conductive agents are used to fill the gaps between the main material particles, or slender tubular conductive agents are used to connect the main material particles. This can not only effectively improve the compaction density, but also build a complete conductive network to make up for the problem of poor conductivity.

[0033] In some embodiments, the conductive agent composition includes the sheet-like conductive agent, the spherical conductive agent, and the tubular conductive agent. The combined use of these three shapes of conductive agents further improves the compaction density of the positive electrode sheet. Specifically, the sheet-like conductive agent can undergo deformations such as "slippage" and "bending" during the compaction process of the positive electrode sheet, fully filling the active material through its own plasticity and toughness; on the other hand, the sheet-like conductive agent can construct a conductive network framework, ensuring the conductivity of the positive electrode sheet, that is, the sheet-like conductive agent can fix the active material to form an overall framework structure through bending and other deformations; while the tubular conductive agent can be fully embedded between the particles of the active material, connecting the active material, the spherical conductive agent, and the sheet-like conductive agent to construct a complete conductive network, ensuring the excellent short-range and long-range conductivity of the electrode sheet. Therefore, the conductive agent composition of this application can effectively improve the compaction density while improving conductivity.

[0034] It should be noted that the descriptions used in this article, such as "spherical conductive agent," "flake conductive agent," and "tubular conductive agent," refer to the shape of the conductive agent particles. It can be understood that "spherical," "flake," and "tubular" means approximately spherical, flake, and tubular, respectively. Taking spherical conductive agent as an example, the spherical conductive agent particles can be ideally spherical or approximately spherical.

[0035] In this text, "flake diameter" refers to the particle size of the Dv50 sheet-like conductive agent. The flake diameter can be measured using a laser particle size analyzer, and the particle size test method is described in GB / T 24533-2019.

[0036] It is understood that the sheet-like conductive agent used in this application includes at least two sheet-like conductive agents with different sheet diameters. In some embodiments, the sheet-like conductive agent includes at least two sheet-like conductive agents with different sheet diameters. By using sheet-like conductive agents with different sheet diameters, the larger sheet diameter conductive agent can construct a long-range conductive network, while the smaller sheet diameter conductive agent can be dispersed between the main materials, effectively improving the compaction density through slippage characteristics. This achieves a balance between higher compaction density and better conductivity.

[0037] In some embodiments, the sheet-like conductive agent includes small-diameter conductive agents and large-diameter conductive agents. The large-diameter conductive agent can fix the active material into an overall framework structure through bending and other deformations, while the small-diameter conductive agent is embedded in the gaps between the active material particles to further increase the compaction density. This conductive agent composition employs a multi-parameter discontinuous gradation method to optimize the gradation of the conductive agent's shape, size, etc., resulting in a novel conductive agent composition.

[0038] In this article, multi-parameter discontinuous gradation refers to grading multiple parameters of the same material, where the parameters have discontinuous values; dense gradation refers to a material in which the particles are in close contact after gradation design and compaction. Material in this state is called dense gradation material.

[0039] In some embodiments, the flake diameter L1 of the small-diameter conductive agent satisfies 0.1μm≤L1<5μm, for example: 0.1μm, 0.5μm, 1μm, 2μm, 3μm, 4μm, 4.9μm, etc.; in some specific examples, the flake diameter of the small-diameter conductive agent is 1μm.

[0040] In some embodiments, the diameter L2 of the large-diameter conductive agent satisfies 5μm≤L2≤20μm, for example: 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, etc.; in some specific examples, the diameter of the large-diameter conductive agent is 7μm.

[0041] With the above-mentioned sheet diameter range, the effect of improving compaction density is better, and it is also more conducive to the construction of a conductive network framework in the positive electrode sheet by the sheet conductive agent, thereby improving conductivity.

[0042] In some embodiments, the specific surface area of ​​the spherical conductive agent is 60 m². 2 / g~120m 2 / g, for example: 60m 2 / g、70m 2 / g、80m 2 / g、90m 2 / g, 100m 2 / g、110m2 / g、120m 2 / g, etc.; in some specific examples, the specific surface area of ​​the spherical conductive agent is 60m². 2 / g. This makes it easier for the spherical conductive agent to disperse in the positive electrode active material, resulting in a better effect on improving the compaction density.

[0043] In this article, specific surface area has a well-known meaning in the field, namely the surface area per unit mass, which can be specifically measured by a specific surface area pore size analyzer, and can be referred to GB / T 19587-2004.

[0044] In some embodiments, the oil absorption value of the spherical conductive agent is ≥200mL / 100g, for example: 200mL / 100g, 240mL / 100g, 280mL / 100g, 320mL / 100g; in some specific examples, the oil absorption value of the carbon black is 320mL / 100g. This further facilitates the diffusion of ions within the electrode by the spherical conductive agent, enabling the formation of a short-range conductive network, improving the battery's electrical performance, and simultaneously increasing the packing density and compaction density.

[0045] In this article, the oil absorption value is an important parameter for evaluating the structural characteristics of spherical conductive agents. It represents the ability of the surface and internal pores of the spherical conductive agent to absorb a certain amount of oil (usually dibutyl phthalate, DBP). This value reflects the specific surface area and pore structure of the spherical conductive agent and is an indicator for evaluating its ability to absorb oily substances in industrial products such as inks, coatings, and plastics. Specifically, it can be tested using an oil absorption meter; refer to the test method for oil absorption value in GB / T 3780.2-2003.

[0046] In some embodiments, the tubular conductive agent includes a high aspect ratio conductive agent and a low aspect ratio conductive agent, wherein the aspect ratio N1 of the low aspect ratio conductive agent satisfies 100 ≤ N1 < 1000, and the aspect ratio N2 of the high aspect ratio conductive agent satisfies 1000 ≤ N2 ≤ 50000. Within this range, the electrical performance of the positive electrode using this conductive agent composition can be further improved.

[0047] In some embodiments, the aspect ratio N2 of the high aspect ratio conductive agent is ≥ 10:1 compared to the aspect ratio N1 of the low aspect ratio conductive agent. Tubular conductive agents with different aspect ratios can be fully embedded between particles, connecting the active material, spherical conductive agents, and sheet-like conductive agents to construct a complete conductive network, ensuring excellent short-range and long-range conductivity of the electrode.

[0048] In some embodiments, the mass ratio of the high aspect ratio conductive agent to the low aspect ratio conductive agent can be 100:0 to 0:100 (excluding point 0), for example: 90:10, 70:30, 50:50, 30:70, 10:90; in some specific examples, the mass ratio of the low aspect ratio conductive agent to the high aspect ratio conductive agent can be 60:40.

[0049] In the text, "aspect ratio" refers to the ratio of the length to the diameter of the tubular conductive agent particles. The aspect ratio can be calculated by statistically analyzing the length and diameter of the tubular conductive agent using scanning electron microscopy.

[0050] In some embodiments, based on the total mass of the conductive agent composition, the mass percentages of the sheet-like conductive agent, the spherical conductive agent, and the tubular conductive agent are a, b, and c, respectively, where a, b, and c satisfy: 1>a>0, 1>b≥0, 1>c≥0, and |b+c|≥a≥|bc|, wherein b and c are not simultaneously 0. Thus, the mass percentages of the first and second conductive agents in the conductive agent composition satisfy the above ranges. On the one hand, the self-slipping properties of the sheet-like conductive agent enhance compaction; on the other hand, it works with the active main material to construct a conductive network framework. The total content of the spherical and tubular conductive agents is slightly higher than that of the sheet-like conductive agent, thus improving the conductive network structure and preventing a decrease in conductivity that might be caused by excessive sheet-like conductive agent.

[0051] In some specific embodiments, a, b, and c satisfy the following conditions: 0.5 ≥ a ≥ 0.2, 0.5 ≥ b ≥ 0, and 0.5 ≥ c ≥ 0. Specifically, a can be 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, etc.; b can be 0, 0.1, 0.2, 0.3, 0.4, 0.5, etc.; and c can be 0, 0.1, 0.2, 0.3, 0.4, 0.5, etc. Therefore, conductive agents of different shapes in the conductive agent composition can better cooperate and synergistically improve the compaction density and conductivity of the battery.

[0052] It is understood that the conductive agent composition can be provided in slurry form. As an example, the conductive agent composition described above can be dissolved in a solvent to obtain the slurry, and the solvents that can be used include, but are not limited to, N-methylpyrrolidone (NMP), 1,5-dimethyl-2-pyrrolidone, and N,N-dimethylformamide.

[0053] Understandably, the modified design of the conductive agent in this application avoids changes in the overall formulation caused by changes in the active main material, making it highly feasible. On the other hand, it reduces the amount of auxiliary material used and lowers the cost.

[0054] It is understood that the specific types of sheet-like conductive agents, spherical conductive agents, and tubular conductive agents can be flexibly selected as needed. In some embodiments, the sheet-like conductive agent includes at least one of graphene and graphite flakes; the spherical conductive agent includes carbon black; and the tubular conductive agent includes at least one of carbon nanotubes and conductive carbon fibers.

[0055] In some embodiments, carbon black may be one or a combination of acetylene black, furnace black, and conductive carbon black Super P. As a zero-dimensional conductive agent, carbon black with low specific surface area and high oil absorption value is more easily dispersed in the active host material.

[0056] In some embodiments, the carbon nanotubes used in this application may be one or a combination of single-walled, oligo-walled, and multi-walled nanotubes.

[0057] As an example, the conductive agent composition of this application may include graphene, carbon black, and carbon nanotubes, wherein the graphene includes large-diameter graphene with a sheet diameter of 5 μm to 10 μm and small-diameter graphene with a sheet diameter of 0.1 μm to 3 μm; the carbon black has a specific surface area of ​​60 m². 2 / g~80m 2 / g, oil absorption value ≥250mL / 100g; carbon nanotubes include high aspect ratio carbon nanotubes and low aspect ratio carbon nanotubes. The aspect ratios of both high aspect ratio carbon nanotubes and low aspect ratio carbon nanotubes fall within the range of 500 to 10000, and the aspect ratio of high aspect ratio carbon nanotubes: aspect ratio of low aspect ratio carbon nanotubes ≥10:1.

[0058] In a second aspect of this application, a positive electrode is provided, comprising the conductive agent composition described in the first aspect.

[0059] It is understood that a positive electrode generally includes a positive current collector and a positive electrode coating layer located on at least one surface of the positive current collector, wherein the positive electrode coating layer includes the conductive agent composition described above. The current collector of the positive electrode can be aluminum foil or composite aluminum foil, so as to serve as a support for the positive electrode.

[0060] In some embodiments, the positive electrode coating layer further includes a positive electrode active material and a binder, wherein the mass ratio of the conductive agent composition, the binder, and the positive electrode active material is 0.01–0.3:0.005–0.1:1, for example: 0.01:0.05:1, 0.05:0.01:1, 0.1:0.03:1, 0.15:0.05:1, 0.2:0.07:1, 0.3:0.1:1, etc.; in some specific examples, the mass ratio of the conductive agent composition, the binder, and the positive electrode active material can be 0.3:0.02:1. Thus, when this positive electrode sheet is applied to a battery, the battery's energy density can be higher, and the structural reliability of the positive electrode sheet can be improved.

[0061] To achieve higher compaction density, the Dv50 particle size of the positive electrode active material can be similar to that of the small-diameter conductive agent. Specifically, |Dv50 particle size of the positive electrode active material - small-diameter conductive agent particle size| ≤ 1 μm. Therefore, with conductive agents and positive electrode active materials of similar particle sizes, the conductive agent can fully utilize its plasticity and toughness during the rolling process, and by making reasonable use of the voids between the positive electrode active material particles, a higher compaction density can be achieved.

[0062] In some embodiments, the Dv50 particle size of the positive electrode active material is 3μm to 7μm, specifically 3μm, 3.5μm, 4μm, 4.5μm, 5μm, 5.5μm, 6μm, 6.5μm, and 7μm. In this application, Dv50 refers to the particle size corresponding to a sample where the cumulative volumetric particle size distribution percentage reaches 50%. Its physical meaning is that particles larger than Dv50 occupy 50% of the volume, and particles smaller than Dv50 also occupy 50% of the volume. Dv50 is also called the median diameter or median particle size. It can be detected using a laser particle size analyzer.

[0063] In some embodiments, the specific type of positive electrode active material is not particularly limited. In some embodiments, the positive electrode active material includes sodium-ion battery positive electrode material or lithium-ion battery positive electrode material; the sodium-ion battery positive electrode material includes at least one of transition metal oxides, polyanionic compounds, organic polymers, and Prussian blue materials; the lithium-ion battery positive electrode material may include at least one of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium nickel manganese oxide, lithium nickel oxide, lithium manganese oxide, lithium cobalt oxide, lithium iron phosphate, and lithium manganese iron phosphate.

[0064] In some embodiments, the binder includes, but is not limited to, one or a combination of several of the following: polyvinylidene fluoride, polyacrylonitrile, polyimide, perfluorosulfonic acid ionomer, and polytetrafluoroethylene, to bond the positive electrode active material mixed in the positive electrode binder and the conductive agent to the current collector.

[0065] In some embodiments, the positive electrode further includes a dispersant, which includes at least one selected from polyvinylpyrrolidone, sodium lauryl sulfate, sodium lauryl sulfonate, sodium dodecylbenzene sulfonate, polyacrylamide, and sodium carboxymethyl cellulose. This allows for better dispersion of the conductive agent, resulting in a positive electrode with good uniformity and superior performance.

[0066] It is understandable that the positive electrode sheet also includes positive electrode active materials and binders, which means that the positive electrode dressing layer contains positive electrode active materials and binders; the positive electrode sheet also includes dispersants, which also means that the positive electrode dressing layer contains dispersants.

[0067] In some embodiments, the preparation method of the above-mentioned positive electrode sheet may include: mixing a binder and N-methylpyrrolidone (NMP) to prepare a slurry, stirring at low speed and then stirring at high speed to obtain a slurry; adding a conductive agent composition and an active main material to the slurry in sequence, stirring, adjusting the viscosity of the slurry to obtain the desired positive electrode slurry; coating the above-mentioned positive electrode slurry onto a current collector to obtain the desired positive electrode sheet.

[0068] Specifically, the preparation methods for the positive electrode include:

[0069] (1) Preparation of novel conductive agent. NMP, dispersant and conductive agent composition are mixed in a certain proportion and stirred evenly to obtain conductive agent slurry.

[0070] In some embodiments, the mass ratio of dispersant, conductive agent composition, and NMP is 1:1 to 8:18 to 72, for example 1:1:18, 1:2:36, 1:3:36, 1:4:72. In some specific examples, the mass ratio of dispersant, conductive agent composition, and NMP is 1:4:36.

[0071] In some embodiments, the sample addition order may be as follows: First, add the dispersant and NMP, and stir until homogeneous. The stirring speed is 1500 rpm to 2500 rpm, for example, 1500 rpm, 2000 rpm, 2500 rpm, etc., and the stirring time is 60 min to 180 min, for example, 60 min, 90 min, 120 min, 150 min, 180 min, etc. In some specific examples, the stirring speed is 2000 rpm and the stirring time is 60 min. Next, add the sheet-like, spherical, and tubular conductive agent, and stir until homogeneous to obtain the conductive agent slurry.

[0072] Specifically, conductive agents can be added sequentially in the following order: carbon nanotubes (first add carbon nanotubes with larger aspect ratios, then add those with smaller aspect ratios), graphene (first add graphene with larger sheet diameters, then add those with smaller sheet diameters), and carbon black. The stirring speed should be 1500 rpm to 2500 rpm, for example, 1500 rpm / min, 2000 rpm, 2500 rpm, etc. After adding one conductive agent, stirring should be continued for a period of time before adding the next, ranging from 10 min to 60 min, for example, 10 min, 20 min, 30 min, 50 min, 60 min, etc. In some specific examples, the stirring speed is 2000 rpm and the stirring time is 15 min. After all conductive agents have been added, stirring should continue for a period of time, ranging from 60 min to 180 min, for example, 60 min, 90 min, 120 min, 150 min, 180 min, etc. In some specific examples, the stirring time is 120 min.

[0073] (2) Preparation of adhesive solution. Mix the adhesive and NMP in a certain proportion and stir evenly to obtain the desired adhesive solution.

[0074] In some embodiments, the mass ratio of adhesive to NMP is 0.01 to 0.2:1, for example: 0.01:1, 0.05:1, 0.10:1, 0.15:1, 0.20:1, etc. In some specific examples, the mass ratio of adhesive to NMP is 0.03:1.

[0075] In some embodiments, the mixing conditions for the binder and NMP are: first slow mixing, then high-speed mixing.

[0076] In some embodiments, the slow stirring speed is 100 rpm to 500 rpm, for example: 100 rpm, 300 rpm, 500 rpm, etc., and the stirring time is 5 min to 30 min, for example: 5 min, 15 min, 25 min, etc. In some specific examples, the slow stirring speed is 300 rpm and the stirring time is 10 min.

[0077] In some embodiments, the high-speed stirring speed is 1500 rpm to 2500 rpm, for example: 1500 rpm, 2000 rpm, 2500 rpm, etc., and the stirring time is 90 min to 180 min, for example: 90 min, 120 min, 150 min, 180 min, etc. In some specific examples, the high-speed stirring speed is 2000 rpm and the stirring time is 120 min.

[0078] (3) Add the conductive agent slurry to the above adhesive solution and stir evenly to obtain a slurry containing the conductive agent.

[0079] In some embodiments, the stirring speed is 1500 rpm to 2500 rpm, for example: 1500 rpm, 2000 rpm, 2500 rpm, etc., and the stirring time is 60 min to 180 min, for example: 60 min, 90 min, 120 min, 150 min, 180 min, etc. In some specific examples, the stirring speed is 2000 rpm and the stirring time is 60 min.

[0080] (4) Add the active main material to the above-mentioned slurry containing the conductive agent, stir evenly, adjust the viscosity, and obtain the desired positive electrode slurry.

[0081] In some embodiments, the mass ratio of the active ingredient to NMP is 0.5 to 5:1, for example: 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, etc. In some specific examples, the ratio of the active ingredient to NMP is 2:1.

[0082] In some embodiments, the stirring speed is 1500-2500 rpm, for example: 1500 rpm, 2000 rpm, 2500 rpm, etc., and the stirring time is 60-180 min, for example: 60 min, 90 min, 120 min, 150 min, 180 min, etc. In some specific examples, the stirring speed is 2000 rpm and the stirring time is 120 min.

[0083] (5) Coat the above positive electrode slurry onto the current collector and dry it in an oven.

[0084] In some embodiments, the oven temperature is 100℃~130℃, for example: 100℃, 110℃, 120℃, 130℃, etc., and in some specific examples, the oven temperature is 110℃. The drying time is 5~30min, for example: 5min, 10min, 15min, 20min, 25min, 30min, etc., and in some specific examples, the drying time is 20min.

[0085] (6) Place the dried positive electrode sheet in a roller press to roll and form the desired positive electrode sheet.

[0086] In a third aspect of this application, a battery is provided comprising the conductive agent composition described in the first aspect or the positive electrode sheet described in the second aspect. This battery exhibits high compaction density and excellent conductivity.

[0087] It is understood that there are no particular restrictions on the specific type of battery, which can be a primary battery or a secondary battery (including but not limited to lithium-ion batteries, sodium-ion batteries, etc.); the shape of the battery can be cylindrical or square; and the outer packaging can be hard-shell or soft-pack, etc.

[0088] It is understandable that, apart from the aforementioned positive electrode, this battery has the necessary structure and components of a conventional battery. Taking a lithium-ion battery as an example, in addition to the aforementioned positive electrode, it typically includes a negative electrode, a separator, an electrolyte, and an outer packaging. The positive electrode, separator, and negative electrode are formed into an electrode assembly through a winding or stacking process, and the electrode assembly and electrolyte (including electrolyte solution, semi-solid electrolyte, solid electrolyte, etc.) are contained in the outer packaging.

[0089] In a fourth aspect of this application, an electrical device is proposed, which includes the battery described in the third aspect. It should be noted that the features and effects described for the battery in the third aspect of this application also apply to this electrical device, and will not be repeated here.

[0090] According to embodiments of this application, the battery can be used as a power source for the electrical device, or as an energy storage unit for the electrical device. The electrical device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

[0091] The embodiments of this application are described in detail below.

[0092] Example 1

[0093] 1. The composition and formulation of the conductive agent are as follows: The specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value of 300mL / 100g, graphene sheet diameter of 1μm and 5μm, carbon nanotube aspect ratio of 5000 and 500, the mass ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 500) = 50: (20: 5): (15: 10).

[0094] 2. Preparation of the conductive agent composition: Dispersant PVP (polyvinylpyrrolidone) and NMP were mixed at a mass ratio of 1:36, stirred at 2000 rpm / min for 60 min. Then, high aspect ratio carbon nanotubes, low aspect ratio carbon nanotubes, large-diameter graphene, small-diameter graphene, and carbon black were added sequentially. The mass ratio of the conductive agent composition to the dispersant PVP was 4:1. Each addition was spaced 15 min apart. After the carbon black was added, the mixture was stirred for 120 min.

[0095] 3. Preparation of positive electrode sheet: The positive electrode active material is composited with sodium iron phosphate (Na4Fe3P4O). 15 The conductive agent composition, polyvinylidene fluoride, and NMP are mixed in a mass ratio of 100:30:2:50. The mixture is stirred into a positive electrode slurry using a homogenizer and then evenly coated onto aluminum foil (double-sided coating). The slurry is then dried in an oven at 100°C. The dried positive electrode sheet is then rolled and shaped in a roller press to obtain the desired positive electrode sheet.

[0096] Example 2

[0097] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 80m². 2 / g, oil absorption value 200mL / 100g, graphene sheet diameter is 1μm and 5μm, carbon nanotube aspect ratio is 5000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 500) = 50: (20: 5): (15: 10).

[0098] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0099] Example 3

[0100] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 1μm and 5μm, carbon nanotube aspect ratio is 5000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 500) = 50: (5: 20): (15: 10).

[0101] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0102] Example 4

[0103] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 1μm and 10μm, carbon nanotube aspect ratio is 5000 and 500, the ratio of the three is carbon black: graphene (1μm: 10μm): carbon nanotube (5000: 500) = 50: (20: 5): (15: 10).

[0104] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0105] Example 5

[0106] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 1μm and 5μm, carbon nanotube aspect ratio is 5000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 500) = 50: (20: 5): (5: 20).

[0107] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0108] Example 6

[0109] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 1μm and 5μm, carbon nanotube aspect ratio is 30000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (30000: 500) = 50: (20: 5): (15: 10).

[0110] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0111] Example 7

[0112] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 1μm and 5μm, carbon nanotube aspect ratio is 5000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 500) = 40: (25: 10): (15: 10).

[0113] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0114] Example 8

[0115] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 1μm and 5μm, carbon nanotube aspect ratio is 5000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 500) = 40: (20: 5): (20: 15).

[0116] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0117] Example 9

[0118] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 120 m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 1μm and 5μm, carbon nanotube aspect ratio is 5000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 500) = 50: (20: 5): (15: 10).

[0119] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0120] Example 10

[0121] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 1μm and 5μm, carbon nanotube aspect ratio is 5000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 500) = 20: (30: 15): (20: 15).

[0122] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0123] Example 11

[0124] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 1μm and 5μm, carbon nanotube aspect ratio is 5000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 500) = 30: (30: 15): (15: 10).

[0125] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0126] Example 12

[0127] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 1μm and 5μm, carbon nanotube aspect ratio is 5000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 500) = 60: (20: 5): (5: 10).

[0128] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0129] Example 13

[0130] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 0.1μm and 5μm, carbon nanotube aspect ratio is 5000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 500) = 50: (20: 5): (15: 10).

[0131] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0132] Example 14

[0133] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 4.5μm and 5μm, carbon nanotube aspect ratio is 5000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 500) = 50: (20: 5): (15: 10).

[0134] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0135] Example 15

[0136] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 1μm and 20μm, carbon nanotube aspect ratio is 5000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 500) = 50: (20: 5): (15: 10).

[0137] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0138] Example 16

[0139] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 1μm and 5μm, carbon nanotube aspect ratio is 5000 and 100, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (5000: 100) = 50: (20: 5): (15: 10).

[0140] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0141] Example 17

[0142] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter is 1μm and 5μm, carbon nanotube aspect ratio is 50000 and 500, the ratio of the three is carbon black: graphene (1μm: 5μm): carbon nanotube (50000: 500) = 50: (20: 5): (15: 10).

[0143] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0144] Example 18

[0145] The composition and formulation of the conductive agent are as follows: the graphene sheet diameters are 1μm and 5μm, and the aspect ratios of the carbon nanotubes are 5000 and 500, with the ratio of graphene (1μm: 5μm): carbon nanotubes (5000: 500) = (25: 15): (25: 35).

[0146] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0147] Example 19

[0148] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameters of 1μm and 5μm, with a ratio of carbon black: graphene (1μm: 5μm) = 60: (25: 15).

[0149] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0150] Example 20

[0151] The composition and formulation of the conductive agent are as follows: the specific surface area of ​​carbon black is 60m². 2 / g, oil absorption value 300mL / 100g, graphene sheet diameter 5μm, carbon nanotube aspect ratio 500, the ratio of the three is carbon black: graphene (5μm): carbon nanotube (500) = 50:25:25.

[0152] The conductive agent composition, positive electrode preparation process, coating process, and drying conditions are the same as in Example 1.

[0153] Comparative Example 1

[0154] The conductive agent composition and formulation are as follows: Carbon black has a specific surface area of ​​80m². 2 / g, oil absorption value 250mL / 100g, carbon nanotube aspect ratio 1000, the ratio of carbon black: carbon nanotube = 90:10.

[0155] The preparation process of the conductive agent and positive electrode, the coating process, and the drying conditions are the same as in Example 1.

[0156] Comparative Example 2

[0157] The conductive agent composition and formulation are as follows: the graphene sheet diameters are 1μm and 5μm, and the ratio is graphene (1μm: 5μm) = 50:50.

[0158] The preparation process of the conductive agent and positive electrode, the coating process, and the drying conditions are the same as in Example 1.

[0159] Comparative Example 3

[0160] The conductive agent is carbon black, and the specific surface area of ​​carbon black is 60 m². 2 / g, oil absorption value 300mL / 100g.

[0161] The preparation process of the conductive agent and positive electrode, the coating process, and the drying conditions are the same as in Example 1.

[0162] Comparative Example 4

[0163] The composition and formulation of the conductive agent are as follows: the aspect ratio of the carbon nanotubes is 5000 and 500, and the ratio is (5000:500) = (60:40).

[0164] The preparation process of the conductive agent and positive electrode, the coating process, and the drying conditions are the same as in Example 1.

[0165] The compaction density and resistivity of the positive electrode sheets obtained in Examples 1-20 and Comparative Examples 1-4 were tested. The test methods are shown below, and the test results are shown in the table.

[0166] (1) Electrode compaction test: The double-coated electrode was die-cut into 5cm×20cm pieces and placed in a roller press. Rolling was performed under certain pressure conditions, with the pressures set to 1MPa, 1.5MPa and 2MPa respectively.

[0167] (2) Electrode resistivity test: Cut the single-sided coated electrode into a rectangle of appropriate size (e.g., 5cm×7cm), place it in an electrode resistivity meter for testing, set the pressure to 25MPa, and hold the pressure for 15s.

[0168] Test results:

[0169]

[0170]

[0171] The above results show that using a combination of sheet-like conductive agent with at least one of spherical and tubular conductive agents can make the positive electrode sheet have both high compaction density and low resistivity. Through comparative examples and comparative examples, it can be seen that without sheet-like conductive agent, the resistivity increases significantly, while with only one of sheet-like, spherical, or tubular conductive agent, the compaction density decreases significantly.

[0172] Specifically, in combination Figure 1 and Figure 2 illustrate, Figure 1 This indicates that large-diameter graphene sheets are bent and wrapped around the active material, while small-diameter graphene sheets and carbon nanotubes are distributed between the active material particles and are tightly bonded together. At the same time, carbon black is distributed on the surface of the active material to form a conductive network, thus perfecting the conductive network. Figure 2This indicates that carbon nanotubes and carbon black agglomerate and are not uniformly dispersed. There is no graphene to build a framework between the active material particles, and the active main material particles are not tightly bonded together, resulting in a low compaction density. However, the large number of carbon nanotubes present promotes the reduction of resistivity.

[0173] In summary, the conductive agent composition of this application improves the compaction density of the positive electrode and has good conductivity.

[0174] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0175] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0176] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0177] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0178] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0179] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A conductive agent composition, characterized in that, include: A first conductive agent, comprising a sheet-like conductive agent; The second conductive agent includes at least one of spherical conductive agents and tubular conductive agents.

2. The conductive agent composition according to claim 1, characterized in that, The conductive agent composition includes the sheet-like conductive agent, the spherical conductive agent, and the tubular conductive agent.

3. The conductive agent composition according to claim 1 or 2, characterized in that, The specific surface area of ​​the spherical conductive agent is 60 m². 2 / g~120m 2 / g, and / or, the oil absorption value of the spherical conductive agent is ≥200mL / 100g.

4. The conductive agent composition according to any one of claims 1 to 3, characterized in that, The sheet-like conductive agent includes small-diameter conductive agents and large-diameter conductive agents. The sheet diameter L1 of the small-diameter conductive agent satisfies 0.1μm≤L1<5μm, and the sheet diameter L2 of the large-diameter conductive agent satisfies 5μm≤L2≤20μm.

5. The conductive agent composition according to any one of claims 1 to 4, characterized in that, The tubular conductive agent includes a high aspect ratio conductive agent and a low aspect ratio conductive agent. The aspect ratio N1 of the low aspect ratio conductive agent satisfies 100≤N1<1000, and the aspect ratio N2 of the high aspect ratio conductive agent satisfies 1000≤N2≤50000.

6. The conductive agent composition according to any one of claims 5, characterized in that, The aspect ratio N2 of the high aspect ratio conductive agent is greater than or equal to the aspect ratio N1 of the low aspect ratio conductive agent by a ratio ≥ 10:

1.

7. The conductive agent composition according to any one of claims 1 to 6, characterized in that, Based on the total mass of the conductive agent composition, the mass percentages of the sheet-like conductive agent, the spherical conductive agent, and the tubular conductive agent are a, b, and c, respectively, where a, b, and c satisfy: 1>a>0, 1>b≥0, 1>c≥0, and |b+c|≥a≥|bc|, wherein b and c are not simultaneously 0.

8. The conductive agent composition according to claim 7, characterized in that, a, b, and c satisfy: 0.5 ≥ a ≥ 0.2, 0.5 ≥ b ≥ 0, and 0.5 ≥ c ≥ 0.

9. The conductive agent composition according to any one of claims 1 to 8, characterized in that, The sheet-like conductive agent includes at least one of graphene and graphite microflakes; and / or The spherical conductive agent includes carbon black; and / or The tubular conductive agent includes at least one of carbon nanotubes and conductive carbon fibers.

10. A positive electrode plate, characterized in that, The conductive agent composition includes any one of claims 1 to 9.

11. The positive electrode sheet according to claim 10, characterized in that, The positive electrode sheet further includes a positive electrode active material and a binder, wherein the mass ratio of the conductive agent composition, the binder and the positive electrode active material is 0.01-0.3:0.005-0.1:

1.

12. The positive electrode sheet according to claim 10 or 11, characterized in that, The positive electrode also includes a dispersant, which includes at least one of polyvinylpyrrolidone, sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, polyacrylamide, and sodium carboxymethyl cellulose.

13. The positive electrode sheet according to claim 11 or 12, characterized in that, The Dv50 particle size of the positive electrode active material is 3μm to 7μm.

14. The positive electrode sheet according to any one of claims 11 to 13, characterized in that, The sheet-like conductive agent includes large-diameter conductive agents and small-diameter conductive agents, where |Dv50 particle size of the positive electrode active material - the sheet size of the small-diameter conductive agent| ≤ 1 μm.

15. The positive electrode sheet according to any one of claims 11 to 14, characterized in that, The positive electrode active material includes sodium battery positive electrode material or lithium battery positive electrode material; The sodium electrode material includes at least one of transition metal oxides, polyanionic compounds, organic polymers, and Prussian blue materials. The lithium-ion battery cathode material includes at least one of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium nickel manganese oxide, lithium nickel oxide, lithium manganese oxide, lithium cobalt oxide, lithium iron phosphate, and lithium manganese iron phosphate.

16. A battery, characterized in that, It includes the conductive agent composition according to any one of claims 1 to 9, or the positive electrode sheet according to any one of claims 10 to 15.

17. An electrical appliance, characterized in that, Includes the battery as described in claim 16.

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