Electrode plate and preparation method thereof, battery and electric equipment

Abstract

The invention provides an electrode plate and a preparation method thereof, a battery and electric equipment, the electrode plate comprises a current collector and an electrode material layer arranged on at least one functional surface of the current collector, the electrode material layer comprises a plurality of pore channels, and the plurality of pore channels form at least one ordered array. According to the electrode plate provided by the invention, the plurality of pore channels which form the ordered array are introduced into the electrode material layer, so that liquid transport channels of the electrode plate can be increased, the liquid phase diffusion performance of the electrode plate can be enhanced, the electrode plate has a higher ion transport speed, and the rate capability of an assembled battery cell is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of battery devices, and in particular to an electrode sheet and a preparation method thereof, a battery, and an electrical device. Background Art

[0002] With the popularity of consumer electronics such as smartphones, tablets, and laptops, users are increasingly demanding fast charging. Fast-charging batteries require low impedance. To reduce battery impedance, it is usually necessary to further improve the electrolyte diffusion capacity of the electrode sheet.

[0003] Constructing the electrode structure and reasonably improving the overall porosity of the electrode sheet are effective methods to improve the electrolyte diffusion performance of the electrode sheet.

[0004] Existing electrode sheets are mainly made by combining large and small particles and introducing volatile pore-forming agents during mixing. Although these methods can construct electrode sheets with pores, the position and distribution of the pores formed are relatively random, and the process is uncontrollable, resulting in unstable effects on improving liquid phase diffusion performance. Summary of the Invention

[0005] The present invention provides an electrode sheet comprising an ordered liquid phase diffusion channel, which can enhance the liquid phase diffusion performance of the electrode sheet, thereby significantly improving the ion transport performance of the electrode sheet.

[0006] The present invention also provides a method for preparing an electrode sheet, which can prepare the above-mentioned electrode sheet, and the process is simple and easy to control.

[0007] The present invention provides a battery. Since the battery includes the electrode sheet, the battery has good rate capability.

[0008] The present invention also provides an electric device. Since the electric device includes the above-mentioned battery, the electric device can be charged in a short time, thereby reducing the waiting time of the user.

[0009] In a first aspect, the present invention provides an electrode sheet comprising a current collector and an electrode material layer disposed on at least one functional surface of the current collector, wherein the electrode material layer comprises a plurality of pores, and the plurality of pores form at least one ordered array.

[0010] Optionally, the plane where each of the channels is located is parallel to the plane where the current collector is located.

[0011] Optionally, the ordered array comprises parallel arranged through holes.

[0012] Optionally, the ordered array comprises holes arranged in a matrix array.

[0013] Optionally, the diameter of the pore is 1 μm-100 μm;

[0014] And / or, the interval between every two adjacent channels is 1 cm-20 cm.

[0015] Optionally, the vertical distance from the pore to the outer surface of the electrode material layer is m, and the thickness of the electrode material layer on one side is n, wherein 0≤m / n≤1, 0 <n≤300μm。

[0016] Optionally, the pores are formed by the site-occupying and decomposable polymer fibers.

[0017] Optionally, the decomposable polymer fibers include polyglycolide fibers and / or polyvinylene carbonate fibers.

[0018] Optionally, the current collector includes a current collector base layer and a glue layer arranged on at least a portion of the surface of the current collector base layer, and the electrode material layer is arranged on a surface of the glue layer away from the current collector; wherein the glue layer includes a binder and decomposable polymer fibers.

[0019] Optionally, in the adhesive layer, the polymer fibers have a diameter of 1 μm-100 μm;

[0020] And / or, the decomposable polymer fibers include polyglycolide fibers and / or polyvinylene carbonate fibers.

[0021] In a second aspect, the present invention provides a method for preparing the electrode sheet according to the first aspect, wherein the method comprises the following step S2, or the following steps S1 and S2:

[0022] Step S1, coating a glue solution containing decomposable polymer fibers, a binder, and an organic solvent on at least one functional surface of a current collector substrate, and drying the solution to obtain a current collector having a glue layer disposed on at least a portion of the surface;

[0023] Step S2: fix the decomposable polymer fiber on at least one functional surface of the current collector, apply the electrode material slurry on the side of the current collector close to the decomposable polymer fiber, and dry it at 50-150° C. to obtain the electrode sheet.

[0024] In a third aspect, the present invention provides a battery comprising the electrode sheet described in the first aspect.

[0025] In a fourth aspect, the present invention provides an electrical device comprising the battery described in the third aspect.

[0026] The electrode sheet provided by the present invention can increase the liquid transport channels of the electrode sheet and enhance the liquid phase diffusion performance of the electrode sheet by introducing a number of channels forming an ordered array in the electrode material layer, so that the electrode sheet has a faster ion transport speed, thereby greatly improving the rate performance of the assembled battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0028] Figure 1 A schematic cross-sectional view of an electrode sheet including pores according to a specific embodiment of the present invention;

[0029] Figure 2 A schematic cross-sectional view of an electrode sheet including pores according to another embodiment of the present invention;

[0030] Figure 3 A schematic longitudinal cross-sectional view of an electrode sheet according to a specific embodiment of the present invention;

[0031] In the figure, 1-current collector, 2-electrode material layer, 3-pore;

[0032] Figure 4 Schematic diagram of the preparation process of an electrode sheet according to a specific embodiment of the present invention;

[0033] Figure 5 Schematic diagram of a process for preparing an electrode sheet according to another specific embodiment of the present invention;

[0034] Figure 6 This is a comparison chart of the test results of Test Example 3 of the present invention.

[0035] The above drawings illustrate specific embodiments of the present invention, which will be described in more detail below. These drawings and the accompanying description are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be understood that the following embodiments are only illustrative illustrations and explanations of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above contents of the present invention are covered by the scope that the present invention is intended to protect. In the drawings, parts with the same structure are represented by the same numerical labels, and components with similar structures or functions are represented by similar numerical labels. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thickness of the components is appropriately exaggerated in some places in the drawings.

[0037] The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or component referred to must have a specific direction. It is constructed and operated in a specific direction. Therefore, the terms describing the positional relationships in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0038] In the present invention, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components.

[0039] In the existing electrode sheets, pores are formed by introducing a volatile pore-forming agent during mixing, which makes the position and distribution of the formed pores relatively random and the process uncontrollable, resulting in unstable effect on improving the liquid phase diffusion performance of the electrode sheet.

[0040] In order to solve the above problems, the present invention proposes the following technical solutions:

[0041] In a first aspect, the present invention provides an electrode sheet comprising a current collector and an electrode material layer disposed on at least one functional surface of the current collector, wherein the electrode material layer comprises a plurality of pores, and the plurality of pores form at least one ordered array.

[0042] In the present invention, by introducing a number of channels forming an ordered array into the electrode material layer, the liquid transport channels of the electrode sheet can be increased, the liquid phase diffusion performance of the electrode sheet can be enhanced, and the electrode sheet can have a faster ion transport speed, thereby greatly improving the rate performance of the assembled battery cell.

[0043] It can be understood that the electrode sheet of the present invention can be either a positive electrode sheet or a negative electrode sheet; as for the composition and material of the positive electrode sheet and the negative electrode sheet of the battery, the present invention does not specifically limit it. For example, the above-mentioned negative electrode sheet includes a current collector and a negative electrode active material layer located on at least one surface of the current collector, the negative electrode active material layer includes a negative electrode active material, a conductive agent, a binder and a dispersant, the negative electrode active material can be selected from one or more of graphite, hard carbon, soft carbon, silicon-based negative electrode, titanium-based material, nitride, tin, and metallic lithium, the conductive agent can be selected from natural graphite, artificial graphite, carbon black, acetylene black, At least one of piano black, carbon fiber, carbon nanotubes, metal powder, and graphene; the binder can be selected from at least one of carboxymethyl cellulose, styrene-butadiene rubber, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyvinyl alcohol, and sodium polyacrylate; the dispersant can be selected from at least one of sodium carboxymethyl cellulose, triethylhexyl phosphoric acid, and sodium lauryl sulfate; the negative electrode current collector can be a conventional negative electrode current collector in the art, such as copper foil. The above-mentioned positive electrode sheet includes a current collector and a positive electrode active material layer located on at least one surface of the current collector. The positive electrode active material layer includes a positive electrode active material, a conductive agent and a binder. The positive electrode active material includes at least one of lithium cobalt oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium manganese phosphate, lithium iron phosphate, and lithium manganese iron phosphate; the conductive agent can be selected from at least one of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanotubes, metal powder, and graphene; the binder can be selected from at least one of carboxymethyl cellulose, styrene-butadiene rubber, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyvinyl alcohol, and sodium polyacrylate; the material of the positive electrode current collector can be selected from any one or more of copper foil, titanium foil, tin foil, chromium foil, and composite foils of the above metals.

[0044] In some embodiments, the plane where each of the channels is located is parallel to the plane where the current collector is located.

[0045] The plane where each of the pores is located can be understood as the cross section of the pore being parallel to the plane where the current collector is located.

[0046] As for the specific arrangement of the ordered array, technicians can adjust it according to the specific specifications, usage scenarios, and usage requirements of the battery cell. In some embodiments, the ordered array includes parallel arranged straight through holes, see Figure 1 In the figure, α is the interval between adjacent through holes.

[0047] In other embodiments, the ordered array comprises holes arranged in a matrix array, see Figure 2 In the figure, α is the interval between adjacent holes, which is also the width of the rectangle in the matrix array, and β is the length of the rectangle in the matrix array.

[0048] Among them, the ordered array as described above can further improve the liquid transport channel compared to the randomly arranged pore structure in the traditional electrode sheet, thereby enhancing the liquid phase diffusion performance of the electrode sheet and making the electrode sheet have a faster ion transport speed.

[0049] In some embodiments, the diameter of the pore is 1 μm-100 μm;

[0050] And / or, the interval between every two adjacent channels is 1 cm-20 cm.

[0051] In the embodiment described above, by further limiting the diameter and spacing of the pores, it is possible to improve the liquid phase diffusion capacity of the electrode sheet while ensuring the contact area of ​​the active material and the mechanical strength of the electrode sheet, thereby avoiding excessive consumption of active lithium ions by side reactions or fracture or pulverization of the electrode sheet during manufacturing, assembly or cycling.

[0052] Illustratively, the diameter of the pores is any value selected from the group consisting of 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, etc., or a range consisting of any two of them. The interval between each two adjacent pores is any value selected from the group consisting of 1 cm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, 10 cm, 11 cm, 12 cm, 13 cm, 14 cm, 15 cm, 16 cm, 17 cm, 18 cm, 19 cm, 20 cm, etc., or a range consisting of any two of them.

[0053] The pores of the present invention can be distributed on the outer surface of the electrode material layer or at the junction of the electrode material layer and the current collector. Specific technicians can adjust according to the specific specifications, usage scenarios, and usage requirements of the battery cell. In some embodiments, the vertical distance from the pore to the outer surface of the electrode material layer is m, and the thickness of the single surface of the electrode material layer is n, where 0≤m / n≤1, 0μm <n≤300μm。

[0054] In a specific embodiment, the vertical distance from the point where the pore is closest to the electrode material layer to the outer surface of the electrode material layer is m, see Figure 3 .

[0055] In some embodiments, the pores are formed by the site-occupying decomposable polymer fibers.

[0056] As described in the above embodiment, the space in the electrode material layer is first occupied by decomposable polymer fibers, and then the polymer fibers are decomposed to obtain the pores.

[0057] As for the finished electrode sheet of the present invention, it can include the decomposable polymer fibers, that is, the pores are filled with the decomposable polymer fibers.

[0058] In some embodiments, the decomposable polymer fibers include polyglycolide fibers and / or polyvinylene carbonate fibers;

[0059] Among them, polyglycolide (PGA), also known as polyglycolic acid, is a highly crystalline, biodegradable aliphatic polymer. Its decomposability is mainly achieved through simple hydrolysis. The hydrolysis instability of polyglycolide is specifically due to the presence of ester bonds (-COO-) in its main chain. The degradation process has two steps: first, water diffuses into the amorphous region of polyglycolide, causing the ester bonds to cleave; the second step begins after the amorphous region is eroded, and the crystalline region of the polymer is easily hydrolyzed and cleaved. The polymer chains in the crystalline region disintegrate and collapse, and the hydrolysis product of polyglycolide is glycolic acid, which evaporates into gas at 100°C.

[0060] The present invention does not specifically limit the source of polyglycolide, which can be purchased directly or prepared by existing methods. In some embodiments, polyglycolide is mainly prepared by polycondensation of raw materials such as glycolic acid, glycolate, and glycolide under the action of a catalyst; further, the process technology route of polyglycolide fiber includes: (1) dehydration and cyclodimerization of glycolic acid; (2) purification of glycolide intermediate; (3) decompression or sealing tube ring-opening polymerization of glycolide; (4) purification and drying; (5) obtaining polyglycolide; (6) passing polyglycolide through an extruder base to obtain spun yarn; (7) pulling and stretching the spun yarn; (8) polyglycolide fibers of different diameters (2-100 μm) can be obtained according to the extruder die parameters. (9) winding.

[0061] In some specific embodiments, the decomposable polymer fibers include polyglycolide fibers and polyvinylene carbonate fibers, wherein the polyvinylene carbonate fibers can be degraded to release VC during long-term cycling, thereby further improving the cycling performance of the battery.

[0062] In some specific embodiments, the decomposable polymer fiber has a tensile strength of 0.5 GPa to 2 GPa.

[0063] Among them, the above embodiment helps to simplify the preparation process by limiting the tensile strength of the polymer fiber. For example, the polymer fiber is directly fixed above the current collector and then coated with a slurry of active material. The polymer fiber in the above tensile range does not break or basically does not break during the slurry coating process, thereby further ensuring the orderliness of the pores.

[0064] Generally speaking, polyglycolide fibers and polyvinylene carbonate fibers can be divided into monofilaments and woven fibers of multiple monofilaments, and the tensile strength of the decomposable polymer fibers can be adjusted by multi-strand braiding.

[0065] In some embodiments, the current collector includes a current collector base layer and a glue layer disposed on at least a portion of the surface of the current collector base layer, and the electrode material layer is disposed on a surface of the glue layer away from the current collector; wherein the glue layer includes a binder and decomposable polymer fibers.

[0066] In the embodiment described above, by directly disposing a glue layer containing decomposable polymer fibers on the surface of the current collector, pores can be introduced into the glue layer. These pores can cooperate with the above-mentioned ordered channels to further enhance the liquid phase diffusivity of the electrode sheet.

[0067] In some embodiments, in the adhesive layer, the polymer fibers have a diameter of 1 μm to 100 μm;

[0068] and / or, the tensile strength of the decomposable polymer fiber is 0.5 GPa to 2 GPa;

[0069] And / or, the decomposable polymer fibers include polyglycolide fibers and / or polyvinylene carbonate fibers.

[0070] In a second aspect, the present invention provides a method for preparing the electrode sheet according to the first aspect, wherein the method comprises the following step S2, or the following steps S1 and S2:

[0071] Step S1, coating a glue solution containing decomposable polymer fibers, a binder, and an organic solvent on at least one functional surface of a current collector substrate, and drying the solution to obtain a current collector having a glue layer disposed on at least a portion of the surface;

[0072] Step S2: fix the decomposable polymer fiber on at least one functional surface of the current collector, apply the electrode material slurry on the side of the current collector close to the decomposable polymer fiber, and dry it at 50-150° C. to obtain the electrode sheet.

[0073] In some embodiments, step S2 can be achieved by the following process:

[0074] 1) Precession: The decomposable polymer fiber roll, current collector roll, and pole piece roll use synchronous speed motors to maintain a relatively stable feeding speed;

[0075] 2) Thickness control: The height of the polymer fiber in the dressing layer is adjusted by the thickness limit block and the limiting precession wheel;

[0076] 3) Slurry shaping: After the applied slurry enters the drying chamber, it can be quickly shaped in less than 3 minutes to fix the position of the polymer fibers in the dressing layer.

[0077] Since the position of the fiber in the slurry is mainly affected by flow resistance during the uncured period (3 minutes), the moving limit precession wheel and the pole piece roll provide a certain tensile force to maintain the high stability of the fiber during the curing period of the slurry.

[0078] When the ordered array includes parallel through-holes, the electrode sheet preparation process is as follows Figure 4 In the figure, the polyglycolide fiber roll provides polyglycolide fiber, the copper roll provides the current collector, the coating port limit groove: controls the direction of the polyglycolide fiber according to the design parameters α1, α2, α3, and α4, and is combined with the thickness limit block to complete the parallel limit function; the limit precession wheel: has dual functions of precession + thickness, and its routing position height is consistent with the height of the thickness limit block; the slurry nozzle: sprays the slurry; the thickness limit block: the parameter I adjusts the relative position of the polyglycolide fiber in the electrode material layer, thereby controlling the vertical distance m from the channel to the outer surface of the electrode material layer; the drying chamber: provides temperature, wind speed, rapid curing of slurry and fiber; the X-RayCT profile detection: can detect the position of the polyglycolide fiber in the electrode piece.

[0079] When the ordered array includes holes arranged in a matrix array, the preparation process of the electrode is as follows Figure 5 , the meaning of the parameters in the figure refer to Figure 4 .

[0080] In a third aspect, the present invention provides a battery comprising the electrode sheet described in the first aspect.

[0081] When the decomposable polymer includes polyglycolide fibers, to prevent the decomposition products of the polyglycolide fibers from affecting battery performance, the polyglycolide fibers are completely decomposed by washing and / or heating before injection. The battery of the present invention can be manufactured according to conventional methods in the art, such as by stacking the positive electrode sheet, separator, and negative electrode sheet in sequence, assembling the cell through a winding or stacking process, and then packaging and baking the cell, injecting the electrolyte, and then performing hot pressing and other steps to produce the battery.

[0082] For example, the battery may further include a separator. The present invention does not impose any particular limitation on the material of the separator; any known porous separator with electrochemical and chemical stability may be selected. For example, the separator may be made of at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, or polyvinylidene fluoride. The separator may be single-layer or multi-layer.

[0083] The present invention does not particularly limit the above-mentioned electrolyte. For example, an electrolyte comprising an organic solvent and an electrolyte salt may be selected. The organic solvent, as a medium for transporting ions in the electrochemical reaction, may be an organic solvent known in the art for battery electrolytes, such as one or more of fluorocarbonates, fluorocarboxylates, non-fluorocarbonates, fluorocarbonates, non-fluorocarboxylates, fluorocarboxylates, fluoroethers, non-fluoroethers, and tetrahydrofuran. The electrolyte salt, as a source of ions, may be an electrolyte salt known in the art for battery electrolytes, such as one or more of lithium hexafluorophosphate, bistrifluoromethylsulfonyl imide, and lithium bis(fluorosulfonyl)imide.

[0084] In a fourth aspect, the present invention provides an electrical device comprising the battery described in the third aspect.

[0085] It should be noted that the above-mentioned electrical equipment can be any conventional equipment that requires electricity, such as but not limited to computers, electric cars, air conditioners, refrigerators, washing machines, microwave ovens, printers, fax machines, etc.

[0086] To further understand the present invention, the following will clearly and completely describe the technical solutions of the present invention in conjunction with specific embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0087] Unless otherwise specified, all reagents involved in the embodiments of the present invention are commercially available products and can be purchased through commercial channels.

[0088] The model of the polyglycolide fiber is EP0.2 or USP12-0, and the fiber diameter is 20 μm.

[0089] Example 1

[0090] This example provides a positive electrode sheet, including a current collector aluminum foil and an electrode material layer arranged on two functional surfaces of the aluminum foil. The electrode material layer includes a plurality of parallel straight through holes, and the parallel straight through holes form an ordered array. The diameter of the parallel straight through holes is 20 μm and the spacing is 5 cm. The length of the positive electrode sheet is 26 cm, the thickness of the single-sided electrode material layer is 100 μm, and m / n = 0.5.

[0091] The preparation of the positive electrode sheet includes the following steps:

[0092] 1) Lithium iron phosphate material, conductive carbon black, and PVDF were weighed in a mass ratio of 96:2:2, added to a solvent (NMP:water = 95:5), and mixed to obtain a positive electrode slurry with a solid content of 50 wt%;

[0093] 2) Fix the polyglycolide fiber roll and control the rotating wheel speed to be the same so that it and the aluminum foil roll move from left to right simultaneously. The polyglycolide fiber is adjusted to 40 μm from the base surface of the current collector through the thickness limit block and the precession wheel. The positive electrode slurry is applied to the polyglycolide fiber while the fiber is being rolled out (calculated on one side, the polyglycolide fiber accounts for 0.006% of the mass of the electrode material layer). After coating, the positive electrode slurry is quickly blown at about 90°C for 20 minutes to initially dry the electrode slurry.

[0094] 3) After the slurry on one side is dried, the coating process is carried out on the other side of the uncoated current collector. The polyglycolide fiber roll is fixed and the rotating wheel speed is controlled to be the same so that it and the aluminum foil move from left to right at the same time. The polyglycolide fiber is adjusted to 50 μm from the base surface of the current collector by the thickness limit block and the precession position of the precession wheel. The positive electrode slurry is coated while the polyglycolide fiber is rolled out (calculated on one side, the polyglycolide fiber accounts for 0.006% of the mass of the electrode material layer). After coating, the positive electrode slurry is quickly blown at about 90°C for 20 minutes to initially dry the electrode slurry.

[0095] 4) After the electrode is dried, it is rolled and cut into positive electrode sheets. The rolled electrode sheets are placed in a non-dew point environment and left to stand for 14 days to allow the polyglycolide fibers to absorb moisture in the electrode sheets and decompose. The electrode sheets after standing for 14 days are placed in a 110°C oven and baked for 24 hours to promote complete decomposition of the polyglycolide. The oven is further subjected to vacuum conditions (-100 MPa) to completely remove the decomposition products.

[0096] Example 2

[0097] This example provides a negative electrode sheet, including a current collector aluminum foil and an electrode material layer arranged on two functional surfaces of the aluminum foil. The electrode material layer includes a plurality of parallel straight through holes, and the parallel straight through holes form an ordered array. The diameter of the parallel straight through holes is 20 μm and the spacing is 5 cm. The length of the positive electrode sheet is 26.5 cm, the thickness of the single-sided electrode material layer is 90 μm, and m / n = 0.5.

[0098] The preparation of the negative electrode sheet includes the following steps:

[0099] 1) Weighing graphite, conductive carbon black, and PVDF in a mass ratio of 96:2:2, adding them to a solvent (NMP:water = 90:10), mixing them to obtain a positive electrode slurry in a mass ratio of 96:2:2 to obtain a negative electrode slurry;

[0100] 2) Fix the polyglycolide fiber roll and control the rotating wheel speed to be the same so that it and the aluminum foil roll move from left to right simultaneously. The polyglycolide fiber is adjusted to 35 μm from the base surface of the current collector by the thickness limit block and the precession wheel. The negative electrode slurry is applied to the polyglycolide fiber while the fiber is being rolled out (calculated on a single side, the polyglycolide fiber accounts for 0.006% of the mass of the electrode material layer). After coating, the negative electrode slurry is quickly blown at about 90°C for 20 minutes to allow the electrode slurry to be initially dried. The negative electrode sheet is then rolled and cut into pieces to obtain the negative electrode sheet.

[0101] 3) After the slurry on one side is dried, the coating process is carried out on the other side of the uncoated current collector. Fix the polyglycolide fiber roll and control the rotating wheel speed to be the same so that it moves from left to right at the same time as the aluminum foil roll. The polyglycolide fiber is adjusted to 45um from the base surface of the current collector through the thickness limit block and the precession wheel. The negative electrode slurry is coated while the polyglycolide fiber is being rolled out (calculated on one side, the polyglycolide fiber accounts for 0.006% of the mass of the electrode material layer). After coating, blow air quickly at about 90℃ for 20 minutes to allow the electrode slurry to dry initially.

[0102] 4) After the electrode is dried, it is rolled and cut into positive electrode sheets. The rolled electrode sheets are placed in a non-dew point environment and left to stand for 14 days to allow the polyglycolide fibers to absorb moisture in the electrode sheets and decompose. The electrode sheets after standing for 14 days are placed in a 110°C oven and baked for 24 hours to promote complete decomposition of the polyglycolide. The oven is further subjected to vacuum conditions (-100 MPa) to completely remove the decomposition products.

[0103] Example 3

[0104] This example provides a positive electrode sheet, including a current collector aluminum foil and an electrode material layer arranged on two functional surfaces of the aluminum foil. The electrode material layer includes a plurality of matrix through holes, and the parallel through holes form an ordered matrix array. The matrix through holes are 5 cm long and 3 cm wide. The length of the positive electrode sheet is 26 cm, and the thickness of the single-sided electrode material layer is 100 μm, wherein the through hole position is m / n=0.5.

[0105] The preparation of the positive electrode sheet includes the following steps:

[0106] 1) Lithium iron phosphate material, conductive carbon black, and PVDF were weighed in a mass ratio of 96:2:2, added to a solvent (NMP:water = 95:5), and mixed to obtain a positive electrode slurry with a solid content of 50 wt%;

[0107] 2) Fix the polyglycolide fiber roll, the polyglycolide fiber is mesh-woven, the mesh hole is 5 cm long and 3 cm wide, and its height is at the m / n=0.5 position. The base plane is the current collector. Control the rotating wheel speed to be the same so that it and the aluminum foil roll move from left to right at the same time. The polyglycolide fiber is adjusted to 40 μm from the base surface of the current collector by the thickness limit block and the precession wheel precession position. While the polyglycolide fiber is being rolled out, the positive electrode slurry is applied (the polyglycolide fiber accounts for 0.010% of the mass of the electrode material layer). After coating, blow air rapidly at about 90°C for 20 minutes to allow the electrode slurry to be initially dried.

[0108] 3) After the slurry on one side is dried, the coating process is carried out on the other side of the uncoated current collector. Fix the polyglycolide fiber roll and control the rotating wheel speed to be the same so that it moves from left to right at the same time as the copper foil roll. The polyglycolide fiber is adjusted to 40um from the base surface of the current collector through the thickness limit block and the precession wheel. The positive electrode slurry is coated while the polyglycolide fiber is being rolled out (the polyglycolide fiber accounts for 0.01% of the mass of the electrode material layer). After coating, blow air quickly at about 90℃ for 20 minutes to allow the electrode slurry to dry initially.

[0109] 4) After the electrode is dried, it is rolled and cut into positive electrode sheets. The rolled electrode sheets are placed in a non-dew point environment and left to stand for 14 days to allow the polyglycolide fibers to absorb moisture in the electrode sheets and decompose. The electrode sheets after standing for 14 days are placed in a 110°C oven and baked for 24 hours to promote complete decomposition of the polyglycolide. The oven is further subjected to vacuum conditions (-100 MPa) to completely remove the decomposition products.

[0110] Example 4

[0111] This example provides a positive electrode sheet, including a current collector aluminum foil and an electrode material layer arranged on two functional surfaces of the aluminum foil. The electrode material layer includes a plurality of parallel through holes, and the parallel through holes form an ordered matrix array. The diameter of the parallel through holes is 1 μm, the spacing is 1 cm, m / n=0.5, the length of the positive electrode sheet is 26.5 cm, and the thickness of the single-sided electrode material layer is 90 μm.

[0112] The preparation of the positive electrode sheet includes the following steps:

[0113] 1) Lithium iron phosphate material, conductive carbon black, and PVDF were weighed in a mass ratio of 96:2:2, added to a solvent (NMP:water = 95:5), and mixed to obtain a positive electrode slurry with a solid content of 50 wt%;

[0114] 2) Fix the polyglycolide fiber roll and control the rotating wheel speed to be the same so that it and the aluminum foil roll move from left to right simultaneously. The polyglycolide fiber is adjusted to 50 μm from the current collector base through the thickness limit block and the precession wheel. The negative electrode slurry (polyglycolide fiber accounts for 0.00008% of the mass of the electrode material layer) is coated on the polyglycolide fiber while the fiber is being rolled out. After coating, the negative electrode slurry is quickly blown at about 90°C for 20 minutes to allow the electrode slurry to be initially dried, and then rolled and cut into positive electrode sheets.

[0115] 3) After the slurry on one side is dried, the coating process is carried out on the other side of the uncoated current collector. Fix the polyglycolide fiber roll and control the rotating wheel speed to be the same so that it moves from left to right at the same time as the aluminum foil roll. The polyglycolide fiber is adjusted to 50um from the base surface of the current collector through the thickness limit block and the precession wheel. The negative electrode slurry is coated while the polyglycolide fiber is being rolled out (the polyglycolide fiber accounts for 0.00008% of the mass of the electrode material layer). After coating, blow air quickly at about 90°C for 20 minutes to allow the electrode slurry to dry initially.

[0116] 4) After the electrode is dried, it is rolled and cut into positive electrode sheets. The rolled electrode sheets are placed in a non-dew point environment and left to stand for 14 days to allow the polyglycolide fibers to absorb moisture in the electrode sheets and decompose. The electrode sheets after standing for 14 days are placed in a 110°C oven and baked for 24 hours to promote complete decomposition of the polyglycolide. The oven is further subjected to vacuum conditions (-100 MPa) to completely remove the decomposition products.

[0117] Example 5

[0118] This example provides a positive electrode sheet, including a current collector aluminum foil and an electrode material layer arranged on two functional surfaces of the aluminum foil. The electrode material layer includes a plurality of parallel straight through holes, and the parallel straight through holes form an ordered array. The diameter of the parallel straight through holes is 100 μm and the interval is 20 cm. The length of the positive electrode sheet is 26 cm, the thickness of the single-sided electrode material layer is 150 μm, and m / n = 0.5.

[0119] The preparation of the positive electrode sheet includes the following steps:

[0120] 1) Lithium iron phosphate material, conductive carbon black, and PVDF were weighed in a mass ratio of 96:2:2, added to a solvent (NMP:water = 95:5), and mixed to obtain a positive electrode slurry with a solid content of 50 wt%;

[0121] 2) Fix the polyglycolide fiber roll and control the rotating wheel speed to be the same so that it and the aluminum foil roll move from left to right simultaneously. The polyglycolide fiber is adjusted to 25 μm from the base surface of the current collector by the thickness limit block and the precession wheel. The positive electrode slurry is applied while the polyglycolide fiber is being rolled out (the polyglycolide fiber accounts for 0.04% of the mass of the electrode material layer). After coating, the positive electrode slurry is quickly blown at about 90°C for 20 minutes to initially dry the electrode slurry.

[0122] 3) After the slurry on one side has dried, the coating process is carried out on the other side of the uncoated current collector. The polyglycolide fiber roll is fixed and the rotating wheel speed is controlled to be the same, so that it and the aluminum foil move simultaneously from left to right. The polyglycolide fiber is adjusted to 25μm from the base surface of the current collector by the thickness limit block and the precession wheel. The positive electrode slurry (polyglycolide fiber accounts for 0.04% of the mass of the electrode material layer) is coated while the polyglycolide fiber is being rolled out. After coating, a rapid air blow is applied at around 90°C for 20 minutes to initially dry the electrode slurry.

[0123] 4) After the electrode is dried, it is rolled and cut into positive electrode sheets. The rolled electrode sheets are placed in a non-dew point environment and left to stand for 14 days to allow the polyglycolide fibers to absorb moisture in the electrode sheets and decompose. The electrode sheets after standing for 14 days are placed in a 110°C oven and baked for 24 hours to promote complete decomposition of the polyglycolide. The oven is further subjected to vacuum conditions (-100 MPa) to completely remove the decomposition products.

[0124] Example 6

[0125] This example provides a positive electrode sheet, including a current collector aluminum foil coated with polyglycolide fiber and an electrode material layer arranged on two functional surfaces of the current collector aluminum foil coated with polyglycolide fiber, the electrode material layer includes a plurality of parallel straight through holes, and the parallel straight through holes form an ordered array. The diameter of the parallel straight through holes is 20 μm and the interval is 5 cm. The length of the positive electrode sheet is 26 cm, the thickness of the single-sided electrode material layer is 100 μm, and m / n = 0.5.

[0126] The preparation of the positive electrode sheet includes the following steps:

[0127] 1) Fix the polyglycolide fiber roll and control the rotating wheel speed to be the same so that it and the aluminum foil roll move from left to right simultaneously. The polyglycolide fiber is adjusted to 0 μm from the base surface of the current collector by the thickness limit block and the precession wheel. While the polyglycolide fiber is being rolled out, PVDF / NMP (PVDF and NMP mass ratio of 30:70) glue is coated (polyglycolide fibers are arranged in parallel, with two sections 3 cm away from the edge of the current collector and 5 cm equidistantly distributed in the middle). After coating, the current collector is quickly blown at about 90°C for 20 minutes to allow the current collector to dry initially.

[0128] 2) Lithium iron phosphate material, conductive carbon black, and PVDF were weighed in a mass ratio of 96:2:2, added to a solvent (NMP:water = 95:5), and mixed to obtain a positive electrode slurry with a solid content of 50 wt%;

[0129] 3) Fix the polyglycolide fiber roll and control the rotating wheel speed to be the same so that it moves from left to right simultaneously with the aluminum foil roll. The polyglycolide fiber is adjusted to 40 μm from the base surface of the current collector by the thickness limit block and the precession wheel. The positive electrode slurry is applied while the polyglycolide fiber is being rolled out (the polyglycolide fiber accounts for 0.006% of the mass of the electrode material layer). After coating, the positive electrode slurry is quickly blown at about 90°C for 20 minutes to initially dry the electrode slurry.

[0130] 4) After the slurry on one side has dried, the coating process is carried out on the other side of the uncoated current collector. The polyglycolide fiber roll is fixed and the rotating wheel speed is controlled to be the same, so that it and the aluminum foil roll move from left to right simultaneously. The polyglycolide fiber is adjusted to 25μm from the base of the current collector by the thickness limit block and the precession wheel. The positive electrode slurry (polyglycolide fiber accounts for 0.006% of the mass of the electrode material layer) is coated on the polyglycolide fiber while the fiber is being rolled out. After coating, a rapid air blow is applied at around 90°C for 20 minutes to initially dry the electrode slurry.

[0131] 5) After the electrode is dried, it is rolled and cut into positive electrode sheets. The rolled electrode sheets are placed in a non-dew point environment and left to stand for 14 days to allow the polyglycolide fibers to absorb moisture in the electrode sheets and decompose. The electrode sheets, which have been left to stand for 14 days, are placed in a 110°C oven and baked for 24 hours to promote complete decomposition of the polyglycolide. The oven is further subjected to vacuum conditions (-100 MPa) to completely remove the decomposition products.

[0132] Example 7

[0133] This example provides a positive electrode sheet, including a current collector aluminum foil and an electrode material layer arranged on two functional surfaces of the aluminum foil. The electrode material layer includes a plurality of parallel straight through holes, and the parallel straight through holes form an ordered array. The diameter of the parallel straight through holes is 20 μm and the spacing is 5 cm. The length of the positive electrode sheet is 26 cm, the thickness of the single-sided electrode material layer is 100 μm, and m / n = 0.5.

[0134] The preparation of the positive electrode sheet includes the following steps:

[0135] 1) Lithium iron phosphate material, conductive carbon black, and PVDF were weighed in a mass ratio of 96:2:2, added to a solvent (NMP:water = 100:0), and mixed to obtain a positive electrode slurry with a solid content of 50 wt%;

[0136] 2) adding 1 wt% AIBN to vinylene carbonate (VC) to react and form PVC, dissolving the PVC in a DMF solution to form a spinning solution, and then extruding fibers through a spinneret. The diameter of the polyVC fibers was controlled to be 20 μm by controlling the spinneret size, and the polyVC fibers were woven with polyglycolide fibers in a mass ratio of 1:1 to 1:1 to form a functional fiber structure;

[0137] 3) Fix the functional fiber roll and control the rotating wheel speed to be the same so that it moves from left to right simultaneously with the aluminum foil roll. The functional fiber is adjusted to 40 μm from the base surface of the current collector by the thickness limiting block and the precession wheel. The positive electrode slurry (the functional fiber accounts for 0.012 wt% of the mass of the electrode material layer) is coated on the functional fiber while the fiber is being rolled out. After coating, the positive electrode slurry is quickly blown at about 90°C for 20 minutes to initially dry the electrode slurry.

[0138] 4) After the slurry on one side has dried, the coating process is carried out on the other, uncoated current collector side. A functional fiber roll (polyVC:polycaprolactone fiber, 1:1) is fixed and the rotating wheel speed is controlled to be the same, moving it and the aluminum foil roll simultaneously from left to right. The functional fiber is adjusted by the thickness limiter and the precession wheel to keep the fiber 25μm away from the current collector base. As the functional fiber is unwound, the positive electrode slurry is applied (the functional fiber accounts for 0.012% of the electrode material layer by weight). After coating, a rapid air blow is applied at around 90°C for 20 minutes to initially dry the electrode slurry.

[0139] 5) After the electrode is dried, it is rolled and cut into positive electrode sheets. The rolled electrode sheets are placed in a non-dew point environment and left to stand for 14 days to allow the polyglycolide fibers to absorb moisture in the electrode sheets and decompose. The electrode sheets after standing for 14 days are placed in a 110°C oven and baked for 24 hours to promote complete decomposition of the polyglycolide. The oven is further subjected to vacuum conditions (-100 MPa) to completely remove the decomposition products.

[0140] Comparative Example 1

[0141] The preparation of the positive electrode sheet in this example includes the following steps:

[0142] Lithium iron phosphate material, conductive carbon black, PVDF, and polyglycolide are mixed in a mass ratio of 96:2:0.006:2 to form a positive electrode slurry;

[0143] The positive electrode slurry is coated on the surface of the current collector, and after coating, it is quickly blown at about 90°C for 20 minutes; the electrode slurry is initially dried, and then roller-pressed. After rolling, the electrode is placed in a non-dew point environment and left to stand for 14 days to allow the polyglycolide fiber to absorb moisture in the electrode and decompose; the electrode after standing for 14 days is placed in a 110°C oven and baked for 24 hours to promote complete decomposition of the polyglycolide; further, a vacuum condition (-100MPa) is applied to the oven to completely remove the decomposition products, and the positive electrode is cut.

[0144] Comparative Example 2

[0145] The preparation of the negative electrode sheet in this example includes the following steps:

[0146] Graphite, conductive carbon black, PVDF, and polyglycolide are mixed in a mass ratio of 96:2:0.006:2 to form a negative electrode slurry; the negative electrode slurry is coated on the surface of the current collector, and after coating, it is quickly blown at about 90°C for 20 minutes; the electrode slurry is initially dried, and then roller-pressed. After rolling, the electrode is placed in a non-dew point environment and left to stand for 14 days to allow the polyglycolide fiber to absorb moisture in the electrode and decompose; the electrode after standing for 14 days is placed in a 110°C oven and baked for 24 hours to promote complete decomposition of polyglycolide; further, a vacuum condition (-100MPa) is applied to the oven to completely remove the decomposition products, and the negative electrode is cut.

[0147] Comparative Example 3

[0148] The preparation of the positive electrode sheet in this example includes the following steps:

[0149] Lithium iron phosphate material, conductive carbon black, and PVDF are mixed in a mass ratio of 96:2:2 to form a positive electrode slurry;

[0150] The positive electrode slurry is coated on the surface of the current collector, and after coating, it is quickly blown at about 90°C for 20 minutes; the electrode slurry is initially dried, and then roller-pressed. After rolling, the electrode is placed in a non-dew point environment and left to stand for 14 days to allow the polyglycolide fiber to absorb moisture in the electrode and decompose; the electrode after standing for 14 days is placed in a 110°C oven and baked for 24 hours to promote complete decomposition of the polyglycolide; further, a vacuum condition (-100MPa) is applied to the oven to completely remove the decomposition products, and the positive electrode is cut.

[0151] Comparative Example 4

[0152] The preparation of the negative electrode sheet in this example includes the following steps:

[0153] Graphite, conductive carbon black and PVDF are mixed in a mass ratio of 96:2:2 to form a negative electrode slurry; the negative electrode slurry is coated on the surface of the current collector, and after coating, it is quickly blown at about 90°C for 20 minutes; the electrode slurry is initially dried and then rolled. After rolling, the electrode is placed in a non-dew point environment and left to stand for 14 days to allow the polyglycolide fiber to absorb moisture in the electrode and decompose; the electrode after standing for 14 days is placed in a 110°C oven and baked for 24 hours to promote the complete decomposition of polyglycolide; the oven is further subjected to vacuum conditions (-100MPa) to completely remove the decomposition products and cut to obtain the negative electrode sheet.

[0154] Test Example 1

[0155] Assembling batteries using the positive electrode sheets of Examples 1 and 3-7 and the negative electrode sheet of Example 2, respectively, comprises the following steps:

[0156] 1. Assemble the positive and negative electrodes into a 20AH battery cell according to the initial design;

[0157] 2. Vacuum drying at 100℃ for 24 hours;

[0158] 3. Injection: The lithium salt in the electrolyte is 1M LiPF6, the solvent is EC and EMC with a mass ratio of 30:70, VC is added (accounting for 3wt% of the electrolyte mass), and the injection volume is 100g;

[0159] 4. Soaking: Place the battery in a constant temperature room at 50℃ for 5 days.

[0160] 5. Formation: Place the soaked battery on a parallel plate fixture with a pressure of 0.5 MPA. First, use a 0.05C constant current charge to form it, and then use a 0.5C constant current charge to 3.7V.

[0161] 6. Aging: Place the formed cells in a constant temperature room at 50°C and leave them for 5 days.

[0162] 7. Capacity Separation: Allow the aged cells to rest at room temperature for 12 hours. After cooling naturally, place them on a cabinet for capacity separation. The capacity separation process is as follows: ① Discharge at 0.5C to 2.0V; ② Charge at 0.5C constant current to 3.7V, then charge at 3.7V constant voltage until the cutoff current is less than 0.05C; ③ Discharge at 0.5C constant current to 2.0V; ④ Repeat steps ②-③ five times.

[0163] Comparative Test Example 1

[0164] The positive and negative electrodes of Comparative Examples 1 and 2 were assembled into battery cells according to the method of Experimental Example 1.

[0165] Comparative Test Example 2

[0166] The positive and negative electrodes of Comparative Examples 3 and 4 were assembled into battery cells according to the method of Experimental Example 1.

[0167] Test Example 1

[0168] Rate performance test

[0169] 1. Select the battery cells of comparative test example 1, comparative test example 2, and test example 1, with 6 cells in each group;

[0170] 2. SOC adjustment: Place the above cells at 25°C and adjust the SOC to 30% SOC;

[0171] 3. 25℃ DCIR test: Discharge for 10s at a current value of 3 times the capacity value (3C). Record the voltage V0 in the last second of the hold step before discharge and the voltage V1 in the last second of discharge. Calculate the 25℃ DCIR of the cell as (V0-V1) / 3C. Then calculate the average 25℃ DCIR of the 6 cells in each group.

[0172] 4. SOC adjustment: Place the battery cell at 25°C and adjust the SOC to 30% SOC;

[0173] 5. Low temperature thermal balance: Place the battery cell in a -10℃ environmental chamber for 24 hours;

[0174] 6. -10℃ DCIR test: Discharge for 10s at a current value of 3 times the capacity value (3C). Record the voltage V0 in the last second of the shelving step before discharge and the voltage V1 in the last second of discharge. Calculate -10℃ DCIR = (V0-V1) / 3C. Then calculate the average -10℃ DCIR of the 6 cells in each group.

[0175] The above test results are shown in Table 1:

[0176] Table 1:

[0177]

[0178] As can be seen from Table 1, the -10℃ DCIR or 25℃ results of the battery cell are: Test Example < Comparative Test Example 1 < Comparative Test Example 2, indicating that the scheme of the embodiment can more significantly increase the electrolyte diffusion channel than the comparative example, thereby facilitating the improvement of the liquid phase diffusion capacity of the electrode sheet and reducing the DCIR of the battery cell, verifying the effectiveness of the design of orderly enhanced electrolyte diffusion channels.

[0179] Test Example 2

[0180] Additive distribution test

[0181] 1. The battery cells of Comparative Test Example 1, the battery cells of Comparative Test Example 2, and the battery cells of Test Example 1 were selected, with 6 cells in each group. Among them, the battery cells of Comparative Test Example 1, the battery cells of Comparative Test Example 2, and the battery cells in Test Example 1 including the positive electrode sheet of Example 1 were named BG7, BG8, BG9, BG10, BG11, BG12, LO7, LO8, LO9, LO10, LO11, LO12, LT7, LT8, LT9, LT10, LT11, and LT12, respectively;

[0182] 2. Disassemble the battery: Take the outermost and middle positive electrodes of the battery cell in five equal parts. Take three points of the docking line of each battery cell as the test position, mark A, B, and C, and take a 2cm×2cm square piece at each position.

[0183] 3. Record the pole piece mass m0;

[0184] 4. Use ethyl acetate to soak the tablets for 24 hours and record the mass m1;

[0185] 5. The above electrolyte was subjected to GC-MS test, and the mass fraction a was obtained;

[0186] 6. The mass of the dried electrode m2;

[0187] 7. Calculate the mass fraction b = a(m1-m2) / (m2-m0), and calculate the average value of each group of 6 cells;

[0188] The experimental results are shown in Table 2 and Figure 6 .

[0189] Table 2:

[0190]

[0191] As can be seen from Table 2, the distribution uniformity of the additives is: Test Example > Comparative Test Example 1 > Comparative Test Example 2, which shows that the electrode sheet of the embodiment can improve the diffusion performance of the electrolyte and improve the uniformity of the distribution of the additives in the center of the large surface of the battery cell because it contains an ordered array pore structure.

[0192] It should be understood that the present invention is not limited to the exact construction described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof, which is limited only by the appended claims.

Claims

1. An electrode sheet comprising a current collector and an electrode material layer disposed on at least one functional surface of the current collector, characterized in that: The electrode material layer includes a plurality of pores, and the plurality of pores form at least one ordered array.

2. The electrode sheet according to claim 1, characterized in that The plane where each of the pores is located is parallel to the plane where the current collector is located.

3. The electrode sheet according to claim 1 or 2, characterized in that: The ordered array includes parallel arranged through holes.

4. The electrode sheet according to claim 1 or 2, characterized in that: The ordered array includes holes arranged in a matrix array.

5. The electrode sheet according to claim 3 or 4, characterized in that: The diameter of the pores is 1 μm-100 μm; And / or, the interval between every two adjacent channels is 1 cm-20 cm.

6. The electrode sheet according to any one of claims 1 to 5, characterized in that: The vertical distance from the pore to the outer surface of the electrode material layer is m, and the thickness of the electrode material layer on one side is n, wherein 0≤m / n≤1,0 <n≤300μm。 7. The electrode sheet according to any one of claims 1 to 6, characterized in that: The pores are formed by the decomposable polymer fibers.

8. The electrode sheet according to claim 7, characterized in that: The decomposable polymer fibers include polyglycolide fibers and / or polyvinylene carbonate fibers.

9. The electrode sheet according to any one of claims 1 to 8, characterized in that: The current collector includes a current collector base layer and a glue layer arranged on at least a portion of the surface of the current collector base layer, and the electrode material layer is arranged on a surface of the glue layer away from the current collector; wherein the glue layer includes a binder and decomposable polymer fibers.

10. The electrode sheet according to claim 9, characterized in that: In the adhesive layer, the diameter of the polymer fibers is 1 μm-100 μm; And / or, the decomposable polymer fibers include polyglycolide fibers and / or polyvinylene carbonate fibers.

11. A method for preparing an electrode sheet according to any one of claims 1 to 10, characterized in that: The preparation method includes the following step S2, or includes the following steps S1 and S2: Step S1, coating a glue solution containing decomposable polymer fibers, a binder, and an organic solvent on at least one functional surface of a current collector substrate, and drying the solution to obtain a current collector having a glue layer disposed on at least a portion of the surface; Step S2: fix the decomposable polymer fiber on at least one functional surface of the current collector, apply the electrode material slurry on the side of the current collector close to the decomposable polymer fiber, and dry it at 50-150° C. to obtain the electrode sheet.

12. A battery, characterized in that: The invention comprises the electrode sheet according to any one of claims 1 to 10.

13. An electrical device, characterized in that: Including the battery according to claim 12.

Images