Pole piece, battery cell, battery pack and electric equipment

Abstract

The embodiment of the utility model provides a pole piece, a battery cell, a battery pack and electric equipment, and relates to the technical field of automobile accessories. The pole piece comprises a conductive polymerization layer used for providing a rapid transmission channel for electrons; at least one side of the two opposite sides of the conductive polymer layer is provided with the high specific capacity layer; the porous layer is arranged on one side, deviating from the conductive polymerization layer, of the high-specific-capacity layer, and the porous layer is used for providing a plurality of transmission channels for lithium ions. According to the pole piece, the battery cell, the battery pack and the electric equipment, the polarization phenomenon of the pole piece can be relieved while the energy density of the battery cell is maintained.

Description

Technical Field

[0001] This application relates to the field of automotive parts technology, and in particular to an electrode sheet, a battery cell, a battery pack, and an electrical device. Background Technology

[0002] The electrodes of a battery cell are the core components that enable energy storage and release. The electrodes include positive and negative electrodes. The charging and discharging process is completed by the insertion and extraction of lithium ions between the positive and negative electrodes.

[0003] In electric vehicles, in order to extend the driving range of the battery cells, thick coating technology is required to process the cells. Thick coating technology increases the coating thickness of the active material on the electrode sheets, thereby increasing the active material load per unit area, which significantly improves the energy density of the battery cells. The increase in energy density directly increases the single-cell capacity of the battery cells, enabling the cells to store more energy and thus extend the driving range of electric vehicles.

[0004] However, while thick coating technology improves the energy density of the battery cell, as the electrode thickness increases, the lithium ion transport distance within the battery cell becomes longer, leading to increased internal resistance and exacerbating polarization. This polarization can affect the performance of the battery cell. Utility Model Content

[0005] This application provides an electrode sheet, a battery cell, a battery pack, and an electrical device to solve the technical problem in related technologies where the use of thick coating technology in battery cells exacerbates the polarization phenomenon, thereby affecting the performance of the battery cells.

[0006] In a first aspect, embodiments of this application provide an electrode sheet, comprising:

[0007] A conductive polymer layer, wherein the conductive polymer layer is used to provide a fast transport channel for electrons;

[0008] A high specific capacity layer, wherein the high specific capacity layer is disposed on at least one of the opposite sides of the conductive polymer layer;

[0009] A porous layer is provided on the side of the high specific capacity layer opposite to the conductive polymer layer, and the porous layer is used to provide multiple transport channels for lithium ions.

[0010] In some embodiments, the conductive polymer layer is a redox layer.

[0011] In some embodiments, the conductive polymer layer includes a current collector and a conductive adhesive layer, wherein the conductive adhesive layer is disposed on the current collector.

[0012] In some embodiments, the current collector is a copper foil.

[0013] In some embodiments, the conductive adhesive layer includes a conductive polymer, which is a doped conjugated polymer.

[0014] In some embodiments, the conductive adhesive layer further includes a first adhesive and an organic solvent, wherein the conductive polymer, the first adhesive, and the organic solvent are mixed to form the conductive adhesive layer.

[0015] In some embodiments, the thickness of the conductive polymer layer is 1 μm-10 μm.

[0016] In some embodiments, the high specific capacity layer comprises a graphite element.

[0017] In some embodiments, the high specific capacity layer further includes a first conductive element, a second binder, and a first dispersant, wherein the graphite element, the first conductive element, the second binder, and the first dispersant are mixed to form the high specific capacity layer.

[0018] In some embodiments, the thickness of the high specific capacity layer is 1 μm-50 μm.

[0019] In some embodiments, the porous layer comprises hard carbon elements.

[0020] In some embodiments, the porous layer further includes a second conductive element, a third binder, and a second dispersant, wherein the hard carbon element, the second conductive element, the third binder, and the second dispersant are mixed to form the porous layer.

[0021] In some embodiments, the thickness of the porous layer is 1 μm-60 μm.

[0022] Secondly, embodiments of this application provide a battery cell, including a battery cell body and electrode sheets disposed on the battery cell body.

[0023] Thirdly, embodiments of this application provide a battery pack, including a frame and battery cells disposed on the frame.

[0024] Fourthly, embodiments of this application provide an electrical device, including a device body and a battery pack disposed on the device body.

[0025] This application provides an electrode sheet, a battery cell, a battery pack, and an electrical device. The electrode sheet provided in this application, by employing a conductive polymer layer, addresses the issue that in thick-coated battery cells, increased lithium-ion transport distance leads to electron transport lag, thus exacerbating polarization. The conductive polymer layer provides a fast conduction channel for electrons, thereby improving electron conduction efficiency and reducing electron transport resistance. This allows lithium ions to acquire or release electrons promptly during insertion or extraction, thus reducing polarization. Furthermore, by employing a high-specific-capacity layer, despite the increased thickness from the thick coating technology, the high specific-capacity layer provides high specific capacity. These characteristics ensure that the battery cell maintains a high energy density even after increasing the active material load, enabling it to store a high amount of energy. When used in electric vehicles, this allows the cell to maintain the vehicle's driving range, thus reducing polarization while storing a high amount of energy. By employing a porous layer, the increased lithium-ion transport distance in thickly coated cells leads to a decrease in rate performance. The porous layer provides multiple transport channels for lithium ions, accelerating their diffusion and reducing the transport time under high-rate charge and discharge conditions, thereby further reducing polarization. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0027] Figure 1 This is a schematic diagram of the structure of the electrode provided in this application;

[0028] Figure 2 for Figure 1 Schematic diagram of the conductive polymer layer;

[0029] Figure 3 for Figure 2 Schematic diagram of the conductive adhesive layer;

[0030] Figure 4 for Figure 1 A schematic diagram of the structure of a medium-to-high specific capacity layer in its unmixed state;

[0031] Figure 5 for Figure 1 A schematic diagram of the structure of the medium porous layer in its unmixed state.

[0032] Explanation of reference numerals in the attached figures:

[0033] 100. Conductive polymer layer; 110. Current collector; 120. Conductive adhesive layer; 121. Conductive polymer component; 122. First adhesive component; 123. Organic solvent component;

[0034] 200, High specific capacity layer; 210, Graphite component; 220, First conductive component; 230, Second adhesive component; 240, First dispersion component;

[0035] 300, porous layer; 310, hard carbon component; 320, second conductive component; 330, third adhesive component; 340, second dispersion component.

[0036] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0037] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0038] In electric vehicles, in order to extend the driving range of the battery cells, thick coating technology is required to process the cells. Thick coating technology increases the coating thickness of the active material on the electrode sheets, thereby increasing the active material load per unit area, which significantly improves the energy density of the battery cells. The increase in energy density directly increases the single-cell capacity of the battery cells, enabling the cells to store more energy and thus extend the driving range of electric vehicles.

[0039] However, while thick coating technology improves the energy density of the battery cell, as the electrode thickness increases, the transport distance of lithium ions within the battery cell becomes longer, leading to an increase in the internal resistance of the battery cell. This results in a relative reduction in the contact area between the electrode surface and the electrolyte, making the adsorption and desorption process of lithium ions on the electrode surface more difficult, worsening the reaction kinetics, and exacerbating the polarization phenomenon of the battery cell. This polarization phenomenon affects the performance of the battery cell.

[0040] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0041] like Figure 1 As shown, an embodiment of this application provides an electrode sheet, comprising:

[0042] The conductive polymer layer 100 is used to provide a fast transport channel for electrons;

[0043] The high specific capacity layer 200 is disposed on at least one of the two opposite sides of the conductive polymer layer 100;

[0044] A porous layer 300 is disposed on the side of the high specific capacity layer 200 away from the conductive polymer layer 100. The porous layer 300 is used to provide multiple transport channels for lithium ions.

[0045] In this embodiment, the electrode is a negative electrode. High specific capacity layers 200 are provided on both sides of the conductive polymer layer 100, and porous layers 300 are provided on the side of the high specific capacity layers 200 away from the conductive polymer layer 100. The thickness of the conductive polymer layer 100 is 1μm-10μm, preferably 0.5μm-2μm; the thickness of the high specific capacity layer 200 is 1μm-50μm, preferably 5μm-40μm; the thickness of the porous layer 300 is 1μm-60μm, preferably 5μm-40μm. In other embodiments, the electrode can also be a positive electrode.

[0046] By employing the conductive polymer layer 100, in thick-coated cells, the increased lithium-ion transport distance leads to electron transport lag, thus exacerbating polarization. The conductive polymer layer 100 provides a fast conduction channel for electrons, thereby improving electron conduction efficiency and reducing electron transport resistance. This allows lithium ions to acquire or release electrons promptly during insertion or extraction, thus reducing polarization. Furthermore, by employing the high specific capacity layer 200, although the thick coating technology increases thickness, the high specific capacity of the high specific capacity layer 200 ensures that the cell can withstand increased active material concentrations. Even under load, the battery maintains a high energy density, enabling the cell to store a significant amount of energy. When used in electric vehicles, this allows the cell to maintain the vehicle's driving range, thus reducing polarization while storing high energy. By employing a porous layer 300, the increased lithium-ion transport distance in thickly coated cells leads to a decrease in rate performance. The porous layer 300 provides multiple transport channels for lithium ions, accelerating their diffusion and reducing the transport time under high-rate charge and discharge conditions, thereby further reducing polarization.

[0047] The conductive polymer layer 100 is a redox layer.

[0048] In this application, by employing a redox layer, the conductive polymer layer 100 of the redox layer has high conductivity, which can significantly improve the conductivity of the electrode. High conductivity can further reduce the polarization phenomenon of the electrode, making the voltage of the cell more stable during charging and discharging. Furthermore, by reducing electrode polarization, the energy loss inside the cell can be reduced, thereby improving the energy efficiency of the cell. During charging and discharging, the redox layer can buffer the volume change of the electrode through its own redox reaction, reducing structural damage caused by volume expansion. In addition, the redox layer can also act as a buffer layer to reduce side reactions between the electrode and the electrolyte, thereby improving the interfacial stability between the electrode and the electrolyte.

[0049] In other embodiments, the conductive polymer layer 100 may also be a non-redox layer. Non-redox layers themselves also have high conductivity, but do not depend on redox reactions. Non-redox layers typically improve conductivity through doping or other means. For example, by adding electron donors (such as alkali metals) or electron acceptors (such as halogens), additional charge carriers can be introduced into the polymer chain. These charge carriers can move freely, thereby improving conductivity.

[0050] Combination Figure 1 and Figure 2 The conductive polymer layer 100 includes a current collector 110 and a conductive adhesive layer 120, with the conductive adhesive layer 120 disposed on the current collector 110.

[0051] In this embodiment, the solid content of the conductive adhesive layer 120 is 20%-60%; the conductive adhesive layer 120 is coated onto the current collector 110 by means of one of microgravure coating, gravure coating and slot coating.

[0052] In this application, by employing the current collector 110, during the cell discharge process, electrons in the conductive adhesive layer 120 are collected by the current collector 110, forming a current. The current collector 110 efficiently conducts the collected current to the external circuit, ensuring that the cell can stably output electrical energy. The conductive adhesive layer 120 is disposed on the surface of the current collector 110, and the mechanical strength of the current collector 110 can prevent the conductive adhesive layer 120 from falling off or deforming during cell assembly and use. The stability of the current collector 110 helps maintain the overall structure of the electrode and reduces damage to the conductive adhesive layer 120 caused by mechanical vibration or chemical reaction.

[0053] The current collector 110 is made of copper foil.

[0054] In this application, the copper foil has a very high electrical conductivity (approximately 5.96 × 10⁻⁶). 7 (S / m) enables efficient electron conduction, reducing internal energy loss within the cell. High conductivity significantly reduces voltage drop during charging and discharging, improving overall performance.

[0055] The actual output voltage and energy efficiency of the battery cell are significantly improved due to the high conductivity of the copper foil. The copper foil allows for rapid current conduction during high-rate charging and discharging, thus increasing the cell's power density. The copper foil possesses high tensile strength and toughness, maintaining its shape during cell assembly and use, preventing the conductive adhesive layer from peeling off. Its good flexibility allows it to adapt to various processing techniques in battery cell manufacturing, such as winding and folding. Furthermore, the copper foil exhibits good corrosion resistance in common electrolyte environments, reducing side reactions with the electrolyte and extending the cell's lifespan.

[0056] In other embodiments, the current collector 110 can be replaced with aluminum foil, stainless steel, or titanium foil, with aluminum having higher conductivity (approximately 3.5 × 10⁻⁶). 7 Stainless steel has high mechanical strength and toughness, enabling it to withstand significant mechanical stress, making it suitable for cell designs requiring high strength. Titanium has relatively high conductivity (approximately 2.4 × 10⁻⁶ S / m), allowing for efficient current conduction. It also possesses high mechanical strength and toughness, enabling it to withstand substantial mechanical stress, making it suitable for high-strength cell designs. 7 (S / m), which can efficiently conduct current.

[0057] Combination Figure 2 and Figure 3 The conductive adhesive layer 120 includes a conductive polymer 121, which is a doped conjugated polymer.

[0058] In this embodiment, the doped conjugated polymer is one of the doped states of polyacetylene, polypyrrole, polythiophene, and polyaniline; the conductivity of the conductive polymer 121 is 10 S / m-106 S / m.

[0059] Polyacetylene: Its conductivity is extremely low when undoped, approaching that of an insulator; by doping with electron acceptors such as iodine (I₂) or bromine (Br₂), its conductivity can be increased to near metallic levels (approximately 10⁻⁶). 4 Polypyrrole: Low conductivity when undoped; conductivity can be significantly improved by doping with acids (such as sulfuric acid, hydrochloric acid, etc.), reaching 10²S / m-10. 4 S / m; Polythiophene: The conductivity is low when undoped, but it can be significantly improved to 10²S / m by doping with acids (such as p-toluenesulfonic acid) or metal salts (such as ferric chloride), reaching 10²S / m-10. 4 S / m; Polyaniline: Its conductivity is low when undoped, but can be significantly improved by doping with acids (such as hydrochloric acid, sulfuric acid, etc.), reaching 10²S / m-10. 4 S / m.

[0060] Doped conjugated polymers have excellent electrochemical properties and are suitable for applications such as battery cells and supercapacitors. Furthermore, doped conjugated polymers have abundant active sites, which can provide high specific capacity, thereby improving the energy density of the battery cell. Doping treatment can improve the mechanical and chemical stability of conductive polymer 121, reduce structural changes during charge and discharge processes, and thus extend the cycle life of the battery cell.

[0061] Combination Figure 2 and Figure 3 The conductive adhesive layer 120 also includes a first adhesive 122 and an organic solvent 123. The conductive polymer 121, the first adhesive 122 and the organic solvent 123 are mixed to form the conductive adhesive layer 120.

[0062] In this embodiment, the first adhesive 122 is one or more of sodium carboxymethyl cellulose (SBR), styrene-butadiene rubber (CMC), polyvinylidene fluoride (PVDF), and polyethylene oxide (PEO); the organic solvent 123 includes deionized water, acetonitrile, methanol, and N-methylpyrrolidone.

[0063] In this application, by adopting the first adhesive 122122, the adhesion between the conductive polymer 121 and the copper foil can be enhanced, ensuring the stability of the conductive polymer 121 during the charging and discharging process. Furthermore, the good adhesion can reduce the contact resistance between the conductive polymer 121 and the copper foil, thereby further improving the conductivity of the electrode. Deionized water, acetonitrile, methanol, and N-methylpyrrolidone (NMP) have many significant advantages in battery cell manufacturing. They can meet the requirements of cleaning, electrolyte preparation, and electrode slurry preparation in the battery cell manufacturing process. The high purity, good solubility, and chemical stability of these solvents make them widely used in the manufacturing of high-performance battery cells.

[0064] The mass ratio of the conductive polymer component 121, the first adhesive component 122, and the organic solvent component 123 is (1-10):(0.1-1):1.

[0065] In this application, the mass ratio of the conductive polymer 121 is between 1 and 10, ensuring that there is sufficient conductive material in the conductive adhesive layer 120, thereby improving the overall conductivity of the electrode; the mass ratio of the first adhesive 122 is between 0.1 and 1, ensuring that the amount of the first adhesive 122 is appropriate, providing sufficient adhesion without excessively affecting the conductivity of the electrode; the mass ratio of the organic solvent 123 is 1, ensuring that the amount of the organic solvent 123 is appropriate, completely dissolving the conductive polymer 121 and the first adhesive 122, while not excessively affecting the drying and molding of the electrode.

[0066] Combination Figure 1 and Figure 4The high specific capacity layer 200 includes graphite elements 210.

[0067] In this application, by employing graphite component 210, graphite, a layered material with an interlayer spacing of approximately 0.335 nanometers, allows lithium ions to intercalate between the graphite layers during the charging and discharging process of the lithium-ion battery cell, forming lithium graphite compounds. This intercalation process creates lithium graphite compounds at different stages, such as LiC6 (where each carbon atom intercalates into one lithium ion). This intercalation process can store a large number of lithium ions, resulting in a high specific capacity. The specific capacity of graphite can reach 372 mAh / g, meaning that each gram of graphite can store 372 milliampere-hours of charge. Graphite possesses excellent electronic conductivity; the carbon atoms in its layered structure form conjugated systems with sp² hybridization, allowing electrons to move freely within these systems. During the charging and discharging process of the battery cell, this excellent electronic conductivity ensures rapid electron transfer, making the lithium-ion intercalation and deintercalation process more efficient. The layered structure of graphite remains relatively stable during lithium-ion intercalation and deintercalation. Although some volume change occurs during charging and discharging, this change is relatively small, and the layered structure of graphite can withstand a certain degree of volume change without structural collapse. This stability allows graphite to maintain a high specific capacity during multiple charge-discharge cycles, thus ensuring the energy density of the cell throughout its entire lifespan.

[0068] In other embodiments, the high specific capacity can also be replaced by silicon-based materials, which have a specific capacity of up to 4200 mAh / g, far exceeding that of graphite (372 mAh / g). Silicon can form a variety of lithium-silicon compounds (such as Li4Si) with lithium, and each silicon atom can embed multiple lithium ions, thereby achieving a high specific capacity.

[0069] Combination Figure 1 and Figure 4 The high specific capacity layer 200 also includes a first conductive element 220, a second adhesive element 230 and a first dispersion element 240. The graphite element 210, the first conductive element 220, the second adhesive element 230 and the first dispersion element 240 are mixed to form the high specific capacity layer 200.

[0070] In this embodiment, the first conductive element 220 is at least one of conductive carbon, carbon nanotubes, graphene, carbon fiber, vapor-grown carbon fiber, activated carbon, porous carbon, acetylene black, and Ketjen black; the second adhesive element 230 is one or more of sodium carboxymethyl cellulose (SBR), styrene-butadiene rubber (CMC), polyvinylidene fluoride (PVDF), and polyethylene oxide (PEO); and the high specific capacity layer 200 has a solid content of 40%-60%.

[0071] In this application, by mixing the first conductive element 220 and the graphite element 210, the conductivity of the electrode can be significantly improved, thereby ensuring that electrons can be transported quickly. By using the second adhesive element 230, the adhesion between the graphite element 210, the first conductive element 220 and the copper foil can be enhanced, thereby ensuring the stability of the graphite element 210 and the first conductive element 220 during the charging and discharging process. By using the first dispersant element 240, the graphite element 210, the first conductive element 220 and the second adhesive element 230 can be prevented from agglomerating during the mixing process, thereby making the graphite element 210, the first conductive element 220 and the second adhesive element 230 uniformly distributed. The uniformly distributed graphite element 210, the first conductive element 220 and the second adhesive element 230 can form a porous structure, increase the specific surface area of ​​the high specific capacity layer 200, provide more active sites for lithium ions and improve the specific capacity of the cell.

[0072] The mass ratio of the graphite part 210, the first conductive part 220, the second adhesive part 230 and the first dispersing part 240 is (90-95): (1-3): (1-3): (1-2).

[0073] In this application, a higher content of graphite 210 (90-95%) ensures that the electrode has a higher specific capacity, thereby improving the energy density of the cell; an appropriate amount of first conductive 220 (1-3) can significantly improve the conductivity of the electrode, reduce the internal power loss of the electrode, and improve the efficiency of the cell; an appropriate amount of second binder 230 (1-3) can significantly enhance the adhesion between the high specific capacity layer 200 and the conductive polymer layer 100, reduce the shedding of the high specific capacity layer 200, and improve the mechanical stability of the electrode; an appropriate amount of first dispersant 240 (1-2) can ensure that the graphite 210 and the first conductive 220 are uniformly distributed during the mixing process, prevent agglomeration, and improve the uniformity of the high specific capacity layer 200.

[0074] Combination Figure 1 and Figure 5 The porous layer 300 includes a hard carbon component 310.

[0075] In this embodiment, the mass ratio of graphite part 210 to hard carbon part 310 is 3:1.

[0076] In this application, by employing a hard carbon component 310, which possesses a porous structure and abundant active sites, lithium-ion transport performance can be significantly improved. In thick-coated cells, increased lithium-ion transport distance leads to a decrease in rate performance, while the porous structure of the hard carbon component 310 provides more transport channels for lithium-ions, accelerating their diffusion. The hard carbon component 310 includes micropores, mesopores, and macropores. Micropores provide a large number of active sites, enabling rapid adsorption and desorption of lithium-ions. These micropores can increase the specific surface area of ​​the electrode material, thereby improving the lithium-ion storage capacity. Mesopores, as lithium-ion transport channels, can accelerate the diffusion of lithium-ions within the porous layer 300. These larger pore sizes reduce the resistance to lithium-ion transport. Macropores facilitate electrolyte penetration, ensuring uniform electrolyte distribution, thereby further improving lithium-ion transport efficiency.

[0077] In other embodiments, the diameter of the porous structures within the porous layer 300 can be set to the same size. For example, the porous structures within the porous layer 300 can all be set to micropores. The advantage of this is that it can provide a large number of active sites, increasing the lithium-ion storage capacity. Alternatively, the porous structures within the porous layer 300 can all be set to mesopores. The advantage of this is that the lithium-ion transport resistance is lower, allowing for rapid diffusion. Or, the porous structures within the porous layer 300 can all be set to mesopores or macropores. The advantage of this is that it allows for better electrolyte permeability and smoother lithium-ion transport paths.

[0078] Combination Figure 1 and Figure 5 The porous layer 300 further includes a second conductive element 320, a third adhesive element 330, and a second dispersant element 340. The hard carbon element 310, the second conductive element 320, the third adhesive element 330, and the second dispersant element 340 are mixed to form the porous layer 300.

[0079] In this embodiment, the second conductive element 320 is at least one of conductive carbon, carbon nanotubes, graphene, carbon fiber, vapor-grown carbon fiber, activated carbon, porous carbon, acetylene black, and Ketjen black; the third adhesive element 330 is one or more of sodium carboxymethyl cellulose (SBR), styrene-butadiene rubber (CMC), polyvinylidene fluoride (PVDF), and polyethylene oxide (PEO); and the solid content of the porous layer 300 is 50%-60%.

[0080] In this application, by mixing the second conductive element 320 and the hard carbon element 310, the conductivity of the electrode can be significantly improved, thereby ensuring rapid electron transport. By employing the third binder 330, the adhesion between the hard carbon element 310, the second conductive element 320, and the copper foil can be enhanced, thereby ensuring the stability of the hard carbon element 310 and the second conductive element 320 during charging and discharging. By employing the second dispersant 340, the hard carbon element 310, the second conductive element 320, and the third binder 330 can be prevented from agglomerating during the mixing process, thereby ensuring that the hard carbon element 310, the second conductive element 320, and the third binder 330 are uniformly distributed. The uniformly distributed hard carbon element 310, the second conductive element 320, and the third binder 330 can form a porous structure, increasing the specific surface area of ​​the electrode material, providing more active sites for lithium ions, and improving the specific capacity of the cell.

[0081] The mass ratio of the hard carbon part 310, the second conductive part 320, the third adhesive part 330, and the second dispersion part 340 is (90-95): (1-3): (1-3): (1-2).

[0082] In this application, a higher hard carbon element 310 (90-95) ensures that the electrode has a higher specific capacity, thereby improving the energy density of the cell; an appropriate amount of second conductive element 320 (1-3) can significantly improve the conductivity of the electrode, reduce the power loss of the electrode, and improve the efficiency of the cell; an appropriate amount of third binder 330 (1-3) can significantly enhance the adhesion between the porous layer 300 and the high specific capacity layer 200, reduce the shedding of the porous layer 300, and improve the mechanical stability of the electrode; an appropriate amount of second dispersant 340 (1-2) can ensure that the hard carbon element 310 and the second conductive element 320 are uniformly distributed during the mixing process, prevent agglomeration, and improve the uniformity of the porous layer 300.

[0083] When it is necessary to prepare the electrode sheet, first add the conductive polymer 121 and the first adhesive 122 into the organic solvent 123, stir evenly, and prepare the conductive adhesive layer 120.

[0084] The conductive adhesive layer 120 is coated on both sides of the current collector 110, and after drying and rolling, the conductive polymer layer 100 is obtained.

[0085] The graphite component 210 and the second adhesive component 230 are added to the first dispersion component 240 and stirred evenly to form a high specific capacity layer 200. The high specific capacity layer 200 is then uniformly coated onto the conductive polymer layer 100 and dried.

[0086] Hard carbon component 310 and third binder 330 are added to second dispersant 340 and stirred evenly to form porous layer 300. The porous layer 300 is then evenly coated on high specific capacity layer 200 and dried to obtain electrode sheet.

[0087] Specifically:

[0088] (1) Redox polyacetylene (PA) with a conductivity of 104 S / cm was selected as the conductive polymer. First, sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR) and deionized water (H2O) were all added to a mixing tank and stirred at 3000 rpm for 120 min. Then, polyacetylene was added and stirred at 3500 rpm for 90 min to obtain conductive adhesive layer 120.

[0089] (2) The conductive adhesive layer 120 is coated on both sides of the copper foil (thickness of 6μm) using a micro-gravure coating machine. After drying and rolling, a conductive polymer layer 100 with a thickness of 1μm and a thickness of 8μm is obtained.

[0090] (3) The graphite component 210, sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR) and the first dispersion component 240 are mixed and stirred to form a slurry, thereby obtaining a high specific capacity layer 200 with a solid content of 50% and a viscosity of 5000 mPa•s. The high specific capacity layer 200 is then coated on the surface of the conductive polymer layer 100 and dried.

[0091] (4) The hard carbon component 310, sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR) and the second dispersion component 340 are mixed and stirred to form a slurry, and a porous layer 300 with a solid content of 50% and a viscosity of 5000 mPa•s is obtained. The porous layer 300 is then coated on the surface of the high specific capacity layer 200 and cold-pressed to obtain the negative electrode sheet.

[0092] The separator, negative electrode, separator, and positive electrode are stacked in sequence, with the separator acting as a barrier between the positive and negative electrodes. They are then wound into a bare cell. The lithium-ion cell is then manufactured through processes including casing, electrolyte injection, formation, and packaging.

[0093] This application also provides a battery cell, including a battery cell body and electrode sheets disposed on the battery cell body according to any of the above embodiments.

[0094] The specific structure of the electrode has been described in detail in the above embodiments, and will not be repeated here.

[0095] This application also provides a battery pack, including a frame and battery cells from any of the above embodiments disposed on the frame.

[0096] This application also provides an electrical device, including a device body and a battery pack of any of the above embodiments disposed on the device body.

[0097] The electrical device provided in this application embodiment, by setting up a battery pack and employing a doped conjugated polymer, addresses the issue that in thick-coated cells, the increased lithium-ion transport distance leads to electron transport lag, thus exacerbating polarization. The doped conjugated polymer provides a fast conduction channel for electrons, thereby improving electron conduction efficiency and reducing electron transport resistance. This allows lithium ions to acquire or release electrons promptly during insertion or extraction, thereby reducing polarization. Furthermore, by employing graphite element 210, although the thick coating technology increases thickness, the high specific capacity of graphite element 210 ensures... Even with increased active material loading, the battery cell maintains a high energy density, enabling it to store a significant amount of energy. When used in electric vehicles, this allows the cell to maintain the vehicle's driving range, thus reducing polarization while storing high energy. By employing hard carbon components 310, the increased lithium-ion transport distance in thickly coated cells leads to a decrease in rate performance. However, the hard carbon components 310 provide multiple transport channels for lithium ions, accelerating their diffusion and reducing transport time under high-rate charge and discharge conditions, further minimizing polarization.

[0098] Finally, it should be noted that other embodiments of this utility model will readily occur to those skilled in the art upon consideration of the specification and practice of the utility model disclosed herein. This utility model is intended to cover any variations, uses, or adaptations of this utility model that follow the general principles of this utility model and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this utility model is limited only by the appended claims.

Claims

1. An electrode sheet, characterized in that, include: A conductive polymer layer (100) is provided to provide a fast transport channel for electrons; A high specific capacity layer (200) is provided on at least one of the opposite sides of the conductive polymer layer (100); A porous layer (300) is provided on the side of the high specific capacity layer (200) away from the conductive polymer layer (100), and the porous layer (300) is used to provide multiple transport channels for lithium ions.

2. The electrode sheet according to claim 1, characterized in that, The conductive polymer layer (100) is a redox layer.

3. The electrode sheet according to claim 1, characterized in that, The conductive polymer layer (100) includes a current collector (110) and a conductive adhesive layer (120), wherein the conductive adhesive layer (120) is disposed on the current collector (110).

4. The electrode sheet according to claim 3, characterized in that, The current collector (110) is a copper foil.

5. The electrode sheet according to claim 3, characterized in that, The conductive adhesive layer (120) includes a conductive polymer (121), which is a doped conjugated polymer.

6. The electrode sheet according to claim 1, characterized in that, The thickness of the conductive polymer layer (100) is 1μm-10μm.

7. The electrode sheet according to any one of claims 1-6, characterized in that, The high specific capacity layer (200) includes a graphite element (210).

8. The electrode sheet according to claim 7, characterized in that, The thickness of the high specific capacity layer (200) is 1μm-50μm.

9. The electrode sheet according to any one of claims 1-6, characterized in that, The porous layer (300) includes a hard carbon element (310).

10. The electrode sheet according to claim 9, characterized in that, The thickness of the porous layer (300) is 1μm-60μm.

11. A battery cell, characterized in that, It includes a cell body and an electrode sheet disposed on the cell body as described in any one of claims 1-10.

12. A battery pack, characterized in that, It includes a frame and a battery cell disposed on the frame as described in claim 11.

13. An electrical appliance, characterized in that, It includes a device body and a battery pack as described in claim 12, disposed on the device body.

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