Modified ceramic material, modified current collector, modified pole piece, preparation method, battery and vehicle

Abstract

The invention discloses a preparation method of a modified ceramic material, the modified ceramic material, a modified negative plate, a modified current collector, preparation methods of the modified negative plate and the modified current collector, a battery and a vehicle. The preparation method of the modified ceramic material comprises the following steps: (1) mixing a solvent, an acidic solution and a silane coupling agent, and standing to obtain a mixed solution; wherein the solvent is a solvent containing hydroxyl; and (2) adding a ceramic material into the mixed solution, and carrying out heating modification to obtain the modified ceramic material. A modified coating of the modified current collector comprises a conductive carbon material, a modified ceramic material and a first binder. When the modified ceramic material is used in a modified coating of a current collector, the problem of potential non-uniform dispersion of the carbon-coated current collector can be improved, the traction force between the obtained modified current collector and an active layer is improved, and the interface adhesive force is enhanced.

Description

Technical Field

[0001] The present invention belongs to the field of batteries, and specifically relates to modified ceramic materials, modified current collectors, modified pole pieces and preparation methods, batteries and vehicles. Background Art

[0002] During the battery production process, the binder is a polymer compound that mixes the active material and the conductive agent and adheres them to the current collector. It has the function of enhancing the contact between the active material, the conductive agent and the current collector, and maintains the mechanical structure of the electrode, the conductive network and the stability of the battery's electrochemical performance during battery production and use.

[0003] The conductive agent has a small particle size and a large surface free energy, which causes the mixture to easily agglomerate, resulting in potential uneven dispersion problems in existing carbon-coated current collectors, affecting conductivity; and the negative electrode has large volume expansion and contraction and binder floating phenomena during the cycle process, especially the new silicon negative electrode material, which reduces the adhesion between the negative electrode active material coating and the negative electrode current collector during the cycle, resulting in the risk of separation of the negative electrode active material coating and the negative electrode current collector, thereby worsening the cycle performance.

[0004] The current solutions to alleviate this phenomenon are generally to modify the active material slurry separately to enhance the adhesion of the active material slurry, or to coat a carbon layer on the current collector (such as sampling carbon-coated copper foil). Although the above methods have the advantage of enhancing adhesion to a certain extent, they are only temporary solutions and cannot provide traction between the current collector and the active layer, cannot effectively enhance the interfacial adhesion, and are prone to detachment. Summary of the Invention

[0005] The first purpose of the present invention is to provide a method for preparing a modified ceramic material and the modified ceramic material obtained, so that when it is used in the modified coating of the current collector, the potential uneven dispersion problem of the carbon-coated current collector can be improved, while the traction between the obtained modified current collector and the active layer can be increased, and the interface adhesion can be enhanced.

[0006] The second object of the present invention is to provide a modified current collector having the aforementioned modified ceramic material and a preparation method thereof, wherein the modified current collector can generate traction with the active layer, thereby effectively enhancing the interfacial adhesion.

[0007] The third object of the present invention is to provide a modified electrode having the aforementioned modified current collector and a preparation method thereof.

[0008] A fourth object of the present invention is to provide a vehicle having the aforementioned modified electrolysis.

[0009] A fifth object of the present invention is to provide a vehicle having the aforementioned battery.

[0010] In order to achieve the first object of the present invention, the following technical solutions are adopted:

[0011] A method for preparing a modified ceramic material, comprising:

[0012] (1) mixing a solvent, an acidic solution, and a silane coupling agent and allowing the mixture to stand to obtain a mixed solution; wherein the solvent is a solvent containing a hydroxyl group;

[0013] (2) Adding ceramic material to the mixed solution for temperature modification to obtain modified ceramic material.

[0014] In one embodiment, the volume ratio of the solvent, the acidic solution and the silane coupling agent is (10-12):(5-6):1.

[0015] In one embodiment, the silane coupling agent includes any one of vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltri(β-methoxyethoxy)silane, or a combination thereof.

[0016] In one embodiment, the mass ratio of the ceramic material to the silane coupling agent is (25-30):1.

[0017] In one embodiment, the ceramic material includes any one of nano-alumina, nano-silica and nano-boehmite, or a combination of several thereof.

[0018] In one embodiment, the solvent includes any one of anhydrous ethanol, isopropyl alcohol, n-propyl alcohol and n-butanol, or a combination thereof.

[0019] In one embodiment, the acidic solution is any one of citric acid solution, potassium citrate solution, sodium citrate solution, lactic acid solution and tartaric acid solution, or a combination of several of them.

[0020] In one embodiment, the concentration of the acidic solution is 4.5 to 8.5 g / mol.

[0021] In one embodiment, in step (1), the solvent, acidic solution, and silane coupling agent are mixed uniformly and then allowed to stand for 1 to 2 hours.

[0022] In one embodiment, in step (2), the modification temperature is 75-85° C., and / or the modification time is 6-8 h, and / or the temperature-raising modification is carried out under stirring in a water bath.

[0023] The present invention also provides a modified ceramic material prepared according to the above preparation method.

[0024] In order to achieve the second purpose of the present invention, the following technical solutions are adopted:

[0025] A modified current collector comprises a current collector and a modified coating coated on the current collector; the modified coating comprises a conductive carbon material, the aforementioned modified ceramic material and a first binder.

[0026] In one embodiment, in the modified coating, the mass ratio of the conductive carbon material, the modified ceramic material and the first binder is (89-93):(6-10):1.

[0027] In one embodiment, the conductive carbon material includes any one or a combination of nano-conductive graphite, graphene, carbon nanotubes and carbon-coated particles.

[0028] The first binder includes polyvinylidene fluoride (PVDF) and / or styrene-butadiene rubber (SBR).

[0029] In one embodiment, the modified coating has a thickness of 1 to 2 μm.

[0030] The present invention also provides a method for preparing the aforementioned modified current collector, comprising:

[0031] The conductive carbon material, the modified ceramic material according to claim 3 and the first binder are uniformly mixed in proportion to obtain a slurry of a modified coating; the obtained slurry of the modified coating is coated on a current collector, and dried to obtain a modified current collector.

[0032] In order to achieve the third object of the present invention, the following technical solutions are adopted:

[0033] A modified pole piece comprises the aforementioned modified current collector and an active layer; wherein the active layer is coated on the modified coating of the modified current collector.

[0034] In one embodiment, the thickness of the active layer is 40 to 55 μm.

[0035] The present invention also provides a method for preparing the aforementioned modified electrode, comprising:

[0036] The active material, the second binder and the conductive agent are mixed uniformly in proportion to obtain a slurry of the active layer; the obtained slurry of the active layer is extruded and coated on the aforementioned modified current collector, and then the coated modified current collector is placed in an oven for drying to obtain a modified electrode.

[0037] In order to achieve the fourth object of the present invention, a battery is further provided, comprising the aforementioned modified electrode sheet or the modified electrode sheet prepared according to the aforementioned preparation method.

[0038] To achieve the fifth object of the present invention, a vehicle is also provided, comprising the aforementioned battery.

[0039] The beneficial effects of the present invention are:

[0040] The method for preparing the modified ceramic material of the present invention comprises the following steps: hydrolyzing a silane coupling agent in an acidic solution in a solvent containing hydroxyl groups, so that the silane coupling agent is hydrolyzed to expose the hydroxyl groups at the inorganic end; then, surface-modifying the ceramic material using the hydrolyzed silane coupling agent so that the inorganic end of the hydrolyzed silane coupling agent is grafted onto the surface of the ceramic material to obtain a modified ceramic material. When the obtained modified ceramic material is used in a modified coating of a current collector, the potential uneven distribution problem of the carbon-coated current collector can be improved, the dispersibility and uniformity of the modified ceramic material coating can be improved, and the traction between the obtained modified current collector and the active layer can be increased, thereby effectively enhancing the interfacial adhesion between the modified current collector and the active layer.

[0041] The modified current collector of the present invention is coated with a modified coating layer comprising the aforementioned modified ceramic material. The modified coating layer comprising the aforementioned modified ceramic material is uniformly dispersed. Thus, after the active layer slurry is coated on the surface of the modified current collector, the organic end of the silane coupling agent in the modified coating layer reacts with the organic group of the second binder in the active layer slurry to form a bond, thereby greatly enhancing the adhesion and traction between the modified current collector and the active material in the active layer.

[0042] In the modified electrode of the present invention, the active layer is coated on the modified current collector. The organic end of the silane coupling agent in the modified coating of the modified current collector reacts with the organic group of the binder in the active layer slurry to form a bond. At the same time, the inorganic end of the silane coupling agent hydrolyzed in the modified coating is grafted onto the ceramic material, which can greatly enhance the adhesion and traction between the modified current collector and the active material in the active layer.

[0043] The battery of the present invention has the aforementioned modified electrode sheet or the modified electrode sheet prepared according to the aforementioned preparation method. The traction between the modified current collector and the active layer is increased, the interfacial adhesion is enhanced, and the modified current collector and the active layer are not easily separated, thereby optimizing the cycle performance of the battery and extending the service life of the battery.

[0044] The vehicle of the present invention has the above-mentioned battery, which is durable and has a long life. DETAILED DESCRIPTION

[0045] The following is a further description of the technical solution and effects of the present invention in conjunction with specific embodiments. The following embodiments are merely illustrative of the present invention, and the present invention is not limited to the following embodiments or examples. Simple changes to the present invention made by applying the concepts of the present invention are within the scope of protection claimed by the present invention.

[0046] The present invention provides a method for preparing a modified ceramic material, comprising:

[0047] (1) mixing a solvent, an acidic solution, and a silane coupling agent and allowing the mixture to stand to obtain a mixed solution; wherein the solvent is a solvent containing a hydroxyl group;

[0048] (2) Adding ceramic material to the mixed solution for temperature modification to obtain modified ceramic material.

[0049] After uniform mixing, the mixture is allowed to stand for 1 to 2 hours (e.g., 1.5 hours) to allow the silane coupling agent to hydrolyze to obtain a mixed solution; the ceramic material is added to the mixed solution and stirred in a water bath at 75 to 85° C. (e.g., 80° C.) for 6 to 8 hours (e.g., 7 hours), followed by suction filtration and drying to obtain the modified ceramic material; wherein,

[0050] In the present invention, the hydrolysis reaction formula of the silane coupling agent is shown in formula (1):

[0051]

[0052] From formula (1), it can be seen that the hydroxyl group at the inorganic end is exposed after hydrolysis of the silane coupling agent;

[0053] The modification reaction formula of ceramic materials (taking nano-alumina as an example) is shown in formula (2):

[0054]

[0055] As can be seen from formula (2), the inorganic end of the silane coupling agent exposed by hydrolysis bonds with the surface hydroxylated ceramic material, thereby achieving surface modification of the ceramic material and obtaining a modified ceramic material.

[0056] The preparation method of the modified ceramic material of the present invention comprises the following steps: hydrolyzing a silane coupling agent in a solvent containing hydroxyl groups using an acidic solution, so that the silane coupling agent is hydrolyzed to expose the hydroxyl groups at the inorganic end; then, surface modification treatment is performed on the ceramic material using the hydrolyzed silane coupling agent, so that the inorganic end of the hydrolyzed silane coupling agent is grafted onto the surface of the ceramic material to achieve modification of the ceramic material, thereby obtaining a modified ceramic material; and when the prepared modified ceramic material is used in a current collector, the potential uneven distribution problem of the carbon-coated current collector can be improved, the dispersibility and uniformity of the current collector coating can be improved, and the traction between the obtained modified current collector and the active layer can be increased, thereby effectively enhancing the interfacial adhesion between the obtained modified current collector and the active layer.

[0057] In the present invention, the main function of the solvent is to provide hydroxyl groups, and the main function of the acidic solution is to provide acidity. If the ratio of the solvent to the acidic solution is too small, the silane coupling agent cannot be fully hydrolyzed; if the ratio of the solvent to the acidic solution is too large, the hydrolysis effect of the silane coupling agent will be affected due to excessive acidity, and it will also cause waste of raw materials. In one embodiment, the volume ratio of the solvent, the acidic solution and the silane coupling agent is (10-12): (5-6): 1, such as (10, 10.5, 11, 11.5 or 12): (5, 5.2, 5.4, 5.5, 5.6, 5.8 or 6): 1, thereby controlling the amount of the solvent and the acidic solution within a suitable range, helping to achieve sufficient hydrolysis of the silane coupling agent and avoiding waste of raw materials.

[0058] In one embodiment, the silane coupling agent includes any one of vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltri(β-methoxyethoxy)silane, or a combination thereof.

[0059] In one embodiment, the solvent includes any one of anhydrous ethanol, isopropyl alcohol, n-propyl alcohol and n-butanol, or a combination thereof.

[0060] In one embodiment, the acidic solution is any one or a combination of citric acid solution, potassium citrate solution, sodium citrate solution, lactic acid (ie, 2-hydroxypropionic acid) solution and tartaric acid (ie, 2,3-dihydroxysuccinic acid) solution.

[0061] In one embodiment, the concentration of the acidic solution is 4.5 to 8.5 g / mol, such as 4.5 g / mol, 5 g / mol, 5.5 g / mol, 6 g / mol, 6.5 g / mol, 7 g / mol, 7.5 g / mol, 8 g / mol and 8.5 g / mol.

[0062] In one embodiment, in step (1), the solvent, acidic solution, and silane coupling agent are mixed uniformly and then allowed to stand for 1 to 2 hours, such as 1.5 hours.

[0063] In the present invention, if the proportion of ceramic material is too high and the proportion of silane coupling agent is too low, the ceramic material cannot be fully modified; if the proportion of ceramic material is too low and the proportion of silane coupling agent is too high, not only will the modification efficiency be reduced, but also the raw materials will be wasted. In one embodiment, the mass ratio of the ceramic material to the silane coupling agent is (25-30):1, such as 26:1, 27:1, 28:1 and 29:1, so that the usage ratio of the two is controlled within an appropriate range, thereby helping to achieve sufficient modification of the ceramic material, ensuring modification efficiency and avoiding raw material waste.

[0064] In one embodiment, the ceramic material includes any one of nano-alumina, nano-silica and nano-boehmite, or a combination of several thereof.

[0065] In one embodiment, in step (2), the modification temperature is 75 to 85°C, such as 78°C, 80°C and 82°C; and / or the modification time is 6 to 8 hours, such as 7.5 hours; and / or the temperature-raising modification is carried out under stirring in a water bath, thereby helping to achieve sufficient modification of the ceramic material.

[0066] The preparation method of the modified ceramic material of the present invention comprises the following steps: hydrolyzing a silane coupling agent using an acidic solution in a solvent containing hydroxyl groups, so that the silane coupling agent is hydrolyzed to expose the hydroxyl groups at the inorganic end; then, surface modification treatment is performed on the ceramic material using the hydrolyzed silane coupling agent, so that the inorganic end of the hydrolyzed silane coupling agent is grafted onto the surface of the ceramic material, thereby obtaining a modified ceramic material; when the obtained modified ceramic material is used in a current collector, the potential uneven distribution problem of the carbon-coated current collector can be improved, the dispersibility and uniformity of the modified ceramic material coating can be improved, and the traction between the obtained modified current collector and the active layer thereon can be increased, thereby effectively enhancing the interfacial adhesion between the obtained modified current collector and the active layer thereon.

[0067] The present invention also provides a modified ceramic material prepared according to the above preparation method.

[0068] The present invention also provides a modified current collector, comprising a current collector and a modified coating applied on the current collector; the modified coating comprises a conductive carbon material, the aforementioned modified ceramic material and a first binder.

[0069] Those skilled in the art understand that the first binder is a binder commonly used in the art, such as polyvinylidene fluoride (PVDF) and / or styrene-butadiene rubber (SBR); the current collector can be a positive electrode current collector (such as aluminum foil) or a negative electrode current collector (such as copper foil), so that the modified current collector can correspond to a modified positive electrode current collector or a modified negative electrode current collector.

[0070] In the modified coating of the present invention, if the ratio of the conductive carbon material, the modified ceramic material and the first binder is not appropriate, the modified ceramic material cannot be effectively coated on the surface of the current collector, the dispersion uniformity and adhesion of the modified coating on the current collector cannot be guaranteed, the coating effect cannot be guaranteed, and raw materials may be wasted. In one embodiment, in the modified coating, the mass ratio of the conductive carbon material, the modified ceramic material and the first binder is (89-93): (6-10): 1; for example, (89, 90, 91, 92 or 93): (6, 7, 8, 9 or 10): 1, thereby taking into account the dispersion uniformity and adhesion of the modified coating on the current collector and the coating effect.

[0071] In one embodiment, the modified coating has a thickness of 1 to 2 μm, such as 1.2 μm, 1.4 μm, 1.5 μm, 1.6 μm and 1.8 μm.

[0072] In one embodiment, the conductive carbon material includes any one or a combination of nano-conductive graphite, graphene, carbon nanotubes and carbon-coated particles.

[0073] In one embodiment, the first binder includes polyvinylidene fluoride and / or styrene-butadiene rubber.

[0074] The modified current collector of the present invention is coated with a modified coating having the aforementioned modified ceramic material. The modified coating having the aforementioned modified ceramic material is evenly dispersed. Therefore, after the active layer slurry is coated on the surface of the aforementioned modified current collector, the organic end of the silane coupling agent in the modified coating reacts with the organic group of the second binder in the active layer slurry to form a bond. At the same time, due to the inorganic end of the silane coupling agent exposed by hydrolysis in the modified coating, it is grafted with the ceramic material, which greatly enhances the adhesion and traction between the aforementioned modified current collector and the active material in the active layer, thereby improving the problems of the binder floating up and the active material separating from the current collector.

[0075] The present invention also provides a method for preparing the aforementioned modified current collector, comprising:

[0076] The conductive carbon material, the modified ceramic material and the first binder are uniformly mixed in proportion to obtain a slurry of a modified coating; the obtained slurry of the modified coating is coated on a current collector, and dried to obtain a modified current collector.

[0077] In one embodiment, in the preparation method of the modified current collector, the drying temperature is 75-85°C, such as 80°C.

[0078] In one embodiment, in the preparation method of the modified current collector, the coating thickness is 3.5 to 5 μm, such as 3.6 μm, 3.8 μm, 4.0 μm, 4.2 μm, 4.4 μm, 4.5 μm, 4.6 μm and 4.8 μm.

[0079] Those skilled in the art understand that the applied slurry becomes a coating after drying. During the drying process, the solvent in the coating evaporates due to drying, and the coating becomes denser and thinner. Therefore, the coating thickness is greater than the coating thickness.

[0080] The present invention also provides a modified electrode, comprising the aforementioned modified current collector and an active layer; wherein the active layer is coated on the modified coating of the modified current collector.

[0081] In one embodiment, in the modified electrode, the active layer includes an active material, a second binder and a conductive agent; preferably, the mass ratio of the active material, the second binder and the conductive agent is (95-97):(2-4):1, such as (95, 95.5, 96, 96.5 or 97):(2, 2.5, 3, 3.5 or 4):1.

[0082] Those skilled in the art will understand that, in the modified electrode sheet, when the modified current collector is a modified positive electrode current collector, the coated active layer is also a positive electrode active layer; the active material is a positive electrode active material, such as a ternary NCM (i.e., LiNi x Co y Mn z O2, x+y+z=1, different ternary systems are obtained according to the different molar ratios x:y:z of the three elements Ni, Co, and Mn, such as LiNi 0.6 Co 0.1 Mn 0.3 O2、LiNi 0.5 Co 0.2 Mn 0.3 O2、LiNi 0.64 Co 0.09 Mn0 .27 O2), such as lithium iron material (such as lithium iron phosphate LiFePO4, lithium ferrous manganese phosphate LiMnFePO4); the second binder is a positive electrode binder, such as polyvinylidene fluoride (PVDF); the conductive agent is a conductive agent commonly used in this field, such as Super P, carbon nanotubes, SP (conductive carbon black), VGCF (vapor grown carbon fiber) in any one or a combination of several; the corresponding modified electrode is a positive electrode modified electrode.

[0083] Those skilled in the art understand that, in the modified electrode sheet, when the modified current collector is a modified negative electrode current collector, the coated active layer is also a negative electrode active layer; the active material is a negative electrode active material, such as graphite; the second binder is a negative electrode binder, such as any one or a combination of polyacrylic acid (PAA), styrene-butadiene rubber (SBR) and sodium carboxymethyl cellulose (CMC); the conductive agent is a conductive agent commonly used in the art, such as any one or a combination of Super P, carbon nanotubes, SP (conductive carbon black), VGCF (vapor-grown carbon fiber); the corresponding modified electrode sheet is a negative electrode modified electrode sheet.

[0084] In one embodiment, the thickness of the active layer is 40-55 μm, such as 42 μm, 44 μm, 45 μm, 46 μm, 48 μm, 50 μm, 52 μm and 54 μm.

[0085] In the modified electrode of the present invention, the active layer is coated on the aforementioned modified current collector. The organic end of the silane coupling agent in the modified coating of the aforementioned modified current collector will react with the organic group of the binder in the active layer slurry to form a bond. At the same time, due to the inorganic end of the silane coupling agent exposed by hydrolysis in the modified coating and grafted with the ceramic material, the adhesion and traction between the aforementioned modified current collector and the active material in the active layer can be greatly enhanced.

[0086] The present invention also provides a method for preparing the aforementioned modified electrode, comprising:

[0087] The active material, the second binder and the conductive agent are mixed uniformly in proportion to obtain an active layer slurry; the obtained active layer slurry is extrusion-coated on the modified current collector, and then the coated modified current collector is placed in an oven for drying to obtain a modified electrode.

[0088] In the aforementioned method for preparing the modified electrode of the present invention, the drying process can cause the organic end of the silane coupling agent on the modified current collector to undergo a bonding reaction with the organic group of the second binder, thereby improving the bonding force between the modified current collector and the active layer.

[0089] In one embodiment, in the method for preparing the modified electrode, the drying temperature is 75-85°C, such as 80°C.

[0090] In one embodiment, in the method for preparing the modified electrode, the coating thickness is 55 to 60 μm, such as 56 μm, 57 μm, 58 μm, 59 μm and 60 μm.

[0091] The preparation method of the modified pole piece of the present invention is simple and easy to implement.

[0092] The present invention also provides a battery having the aforementioned modified electrode piece or the modified electrode piece prepared according to the aforementioned preparation method.

[0093] In one embodiment, the battery includes a positive electrode sheet, a negative electrode sheet, a separator located between the positive electrode sheet and the negative electrode sheet, and an electrolyte; wherein the negative electrode sheet and / or the positive electrode sheet is the aforementioned modified electrode sheet or a modified electrode sheet prepared according to the aforementioned preparation method.

[0094] In one embodiment, the negative electrode sheet is the aforementioned modified negative electrode sheet and / or the positive electrode sheet is the aforementioned modified positive electrode sheet.

[0095] Those skilled in the art will understand that, in the present invention, the diaphragm is a diaphragm commonly used in the art, and the electrolyte is an electrolyte commonly used in the art.

[0096] The present invention also provides a vehicle having the battery.

[0097] Those skilled in the art understand that, in the present invention, "a combination of any one or more items" and "a combination of any one or several items" refer to any one item, a combination of any two items, or even a combination of any more items (such as 3, 4, or 5 items).

[0098] The present invention is further illustrated below by examples and comparative examples.

[0099] The performance testing methods of the batteries obtained in the following examples and comparative examples are as follows:

[0100] 1. Cycle performance test and service life test

[0101] The obtained battery was placed in a constant temperature box at 25°C for 30 minutes, charged to 4.4V at a constant charge rate of 1 / 3C, then charged at a constant voltage to a charge rate of 0.05C, allowed to stand for 5 minutes, and then discharged to 2.5V at a constant discharge rate of 1 / 3C, which was recorded as the initial discharge capacity C0; and then subjected to a cycle test according to the following steps:

[0102] 1) Let it stand for 30 minutes;

[0103] 2) Charge to 4.4V at a constant charge rate of 1 / 3C0; then charge at a constant voltage to a charge rate of 0.05C

[0104] 3) Let it stand for 30 minutes;

[0105] 4) Discharge to 2.5V at a constant discharge rate of 1.0C;

[0106] 5) Step charging to 100% SOC (i.e. fully charged state) at the following rates:

[0107] 1.85C0 constant current charging for 600s;

[0108] 1.75C0 constant current charging 212s;

[0109] 1.55C0 constant current charging 225s;

[0110] 1.4C0 constant current charging 258s;

[0111] 1C0 constant current charging 330s;

[0112] 0.7C0 constant current charging for 450s;

[0113] 0.5C0 constant current charging for 600s;

[0114] 0.4C0 constant current charging for 450s;

[0115] 0.3C0 constant current charging to 4.4V, 4.4V constant voltage charging to 0.05C;

[0116] 6) Let stand for 30 minutes;

[0117] 7) Steps 4) to 6) are cycled to 80% SOH (i.e., 80% health state), and this is recorded as the end of life; according to the cycle x number of cycles at this time, the battery cycle capacity retention rate (%) = C x / C0×100% is used to calculate the cycle capacity retention rate of the battery; the service life of the battery is the number of cycles x when the battery reaches 80% SOH.

[0118] 2. Peeling performance test

[0119] Use a peel tester (Jinan Saicheng FPT-F1) to test the positive and negative electrodes:

[0120] 1) Power on: Turn on the power switch of the peel tester and enter the test operation page;

[0121] 2) Settings: Click the Settings button on the operation panel, set the test value to 10, the test width to 20mm, the sample mode to stroke, and the running speed to 100mm / min;

[0122] 3) Experimental preparation: Wipe the test board and equipment working surface with a clean, dust-free cloth dampened with alcohol. Keep the working surface clean and tidy. Do not touch the working surface with your hands or other objects after cleaning.

[0123] 4) Sample preparation: Prepare the electrode to be tested and cut it into samples with a length of about 400mm and a width of 25mm using a cutting knife;

[0124] Stick the pressure-sensitive 3M-VHB double-sided tape (width 20mm) on the center of the stainless steel test plate. The length should be greater than the test length of the sample. Smooth it firmly to ensure that the double-sided tape is tightly attached to the center of the steel plate.

[0125] Remove the double-sided tape and attach the electrode to the tape. Ensure that the electrode and the tape are symmetrical. Then use a roller to roll the sample three times in the same direction at a speed of about 300 mm / min under its own weight to prepare the sample.

[0126] 5) Test: Place the prepared sample in the test environment for 20-40 minutes and then conduct the following test:

[0127] Insert the steel plate with the sample attached into the pull clamp and fix it. Fix the unattached end of the sample into the upper clamp so that the sample attached to the adhesive tape is 180 degrees from the sample fixed on the upper clamp, and cover it with a protective cover.

[0128] Click the "Test" button in the control panel and wait for the test results. Do not touch the desktop during the test to avoid inaccurate test data.

[0129] Record the measured peel force data in the record sheet and remove the sample to observe its condition;

[0130] Repeat the test three times and take the average value of the three measurements.

[0131] Modified ceramic materials

[0132] Example 1 -1 (S1 -1 )

[0133] The modified ceramic material A1 was prepared according to the following preparation method, comprising:

[0134] The solvent (anhydrous ethanol), acidic solution (citric acid solution, concentration of 6 g / mol), and silane coupling agent (vinyltriethoxysilane) were mixed uniformly in a volume ratio of 11:5.5:1 and allowed to stand for 1.5 hours to hydrolyze the silane coupling agent to obtain a mixed solution; the ceramic material (nano-alumina) was added to the mixed solution and stirred in a water bath at 80°C for 7 hours to increase the temperature for modification, and then filtered and dried at 80°C to obtain modified ceramic material A1.

[0135] Example 1 -2 (S1 -2 )

[0136] According to Example 1 -1 (S1 -1 ) is used to prepare a modified ceramic material A2, wherein:

[0137] The only differences from Example 1 are as follows:

[0138] The volume ratio of the solvent, the acid solution and the silane coupling agent is 10:5:1.

[0139] Example 1 -3 (S1 -3 )

[0140] According to Example 1 -1 (S1 -1 ) is used to prepare a modified ceramic material A3, wherein:

[0141] The only differences from Example 1 are as follows:

[0142] The volume ratio of the solvent, the acid solution and the silane coupling agent is 12:6:1.

[0143] Example 1 -4 (S1 -4 )

[0144] According to Example 1 -1 (S1 -1 ) is used to prepare a modified ceramic material A4, wherein:

[0145] The only differences from Example 1 are as follows:

[0146] The concentration of the citric acid solution is 4.5 g / mol.

[0147] Example 1 -5 (S1 -5 )

[0148] According to Example 1 -1 (S1 -1 ) is used to prepare a modified ceramic material A5, wherein:

[0149] The only differences from Example 1 are as follows:

[0150] The concentration of the citric acid solution is 8.5 g / mol.

[0151] Example 1 -6 (S1 -6 )

[0152] According to Example 1 -1 (S1 -1 ) is used to prepare a modified ceramic material A6, wherein:

[0153] The only differences from Example 1 are as follows:

[0154] The solvent is isopropyl alcohol;

[0155] The acidic solution is a lactic acid solution;

[0156] The silane coupling agent is vinyltrimethoxysilane;

[0157] The ceramic material is nano-silicon dioxide;

[0158] Let stand for 1 hour;

[0159] Stir in a water bath at 75°C for 8 h.

[0160] Example 1 -7 (S1 -7 )

[0161] According to Example 1 -1 (S1 -1 ) is used to prepare a modified ceramic material A7, wherein:

[0162] The only differences from Example 1 are as follows:

[0163] The solvent is n-butanol;

[0164] The acidic solution is a tartaric acid solution;

[0165] The silane coupling agent is vinyl tris (β-methoxyethoxy) silane;

[0166] The ceramic material is nanoboehmite;

[0167] Let stand for 2 hours;

[0168] Stir in a water bath at 85°C for 6 h.

[0169] Modified positive electrode current collector and modified positive electrode sheet

[0170] Example 2 -1 (S2 -1 )

[0171] (1) Prepare the modified positive electrode current collector B1 according to the following preparation method, including:

[0172] The conductive carbon material, the modified ceramic material and the first binder are uniformly mixed in proportion to obtain a modified coating slurry; the obtained modified coating slurry is coated on the positive electrode current collector (aluminum foil), and after drying, a modified positive electrode current collector B1 with a modified coating thickness of 1.2 μm is obtained; wherein,

[0173] The mass ratio of the conductive carbon material, the modified ceramic material and the first binder is 91:8:1;

[0174] The conductive carbon material is nano-conductive graphite;

[0175] The modified ceramic material is modified ceramic material A1;

[0176] The first binder is polyvinylidene fluoride (PVDF);

[0177] The coating thickness is 4 μm;

[0178] The drying temperature is 80°C;

[0179] (2) Prepare the modified positive electrode sheet D1 according to the following preparation method, including:

[0180] The active material, the second binder and the conductive agent are mixed uniformly in proportion to obtain an active layer slurry; the obtained active layer slurry is extrusion-coated on the modified positive electrode current collector, and then the coated modified positive electrode current collector is placed in an oven and dried at 80° C. to obtain a modified positive electrode sheet D1 with an active layer thickness of 47 μm; wherein,

[0181] The mass ratio of the active material, the second binder and the conductive agent is 96:3:1;

[0182] The active material is LiNi 0.6 Co 0.1 Mn 0.3 O2;

[0183] The second binder is polyvinylidene fluoride (PVDF);

[0184] The conductive agent is carbon nanotubes;

[0185] The modified positive electrode current collector is a modified positive electrode current collector B1;

[0186] The coating thickness was 57 μm.

[0187] Example 2 -2 (S2 -2 )

[0188] (1) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode current collector B2, wherein the modified positive electrode current collector B2 was prepared in the same manner as in Example 2. -1 The only differences are:

[0189] The modified ceramic material is modified ceramic material A2;

[0190] In the obtained modified positive electrode current collector B2, the thickness of the modified coating was 1.2 μm;

[0191] (2) According to Example 2 -1 (S2 -1 ) is prepared by the method of preparing the modified positive electrode sheet D2, wherein the modified positive electrode sheet D2 ... -1 The only differences are:

[0192] The modified positive electrode current collector is a modified positive electrode current collector B2;

[0193] In the obtained modified positive electrode sheet D2, the thickness of the active layer was 47 μm.

[0194] Example 2 -3 (S2 -3 )

[0195] (1) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode current collector B3, wherein the modified positive electrode current collector B3 was prepared in the same manner as in Example 2. -1 The only differences are:

[0196] The modified ceramic material is modified ceramic material A3;

[0197] In the obtained modified positive electrode current collector B3, the thickness of the modified coating was 1.2 μm;

[0198] (2) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode sheet D3, wherein the modified positive electrode sheet D3 was prepared in the same manner as in Example 2. -1 The only differences are:

[0199] The modified positive electrode current collector is a modified positive electrode current collector B3;

[0200] In the obtained modified positive electrode sheet D3, the thickness of the active layer was 47 μm.

[0201] Example 2 -4 (S2 -4 )

[0202] (1) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode current collector B4, wherein the modified positive electrode current collector B4 was prepared in the same manner as in Example 2. -1 The only differences are:

[0203] The modified ceramic material is modified ceramic material A4;

[0204] In the obtained modified positive electrode current collector B4, the thickness of the modified coating was 1.2 μm;

[0205] (2) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode sheet D4, wherein the modified positive electrode sheet D4 was prepared in the same manner as in Example 2. -1 The only differences are:

[0206] The modified positive electrode current collector is a modified positive electrode current collector B4;

[0207] In the obtained modified positive electrode sheet D4, the thickness of the active layer was 47 μm.

[0208] Example 2 -5 (S2 -5 )

[0209] (1) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode current collector B5, wherein the modified positive electrode current collector B5 was prepared in the same manner as in Example 2. -1 The only differences are:

[0210] The modified ceramic material is modified ceramic material A5;

[0211] In the obtained modified positive electrode current collector B5, the thickness of the modified coating was 1.2 μm;

[0212] (2) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode sheet D5, wherein the modified positive electrode sheet D5 was prepared in the same manner as in Example 2. -1 The only differences are:

[0213] The modified positive electrode current collector is a modified positive electrode current collector B5;

[0214] In the obtained modified positive electrode sheet D5, the thickness of the active layer was 47 μm.

[0215] Example 2 -6 (S2 -6 )

[0216] (1) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode current collector B6, wherein the modified positive electrode current collector B6 was prepared in the same manner as in Example 2. -1 The only differences are:

[0217] The modified ceramic material is modified ceramic material A6;

[0218] In the obtained modified positive electrode current collector B6, the thickness of the modified coating was 1.2 μm;

[0219] (2) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode sheet D6, wherein the modified positive electrode sheet D6 was prepared in the same manner as in Example 2. -1 The only differences are:

[0220] The modified positive electrode current collector is a modified positive electrode current collector B6;

[0221] In the obtained modified positive electrode sheet D6, the thickness of the active layer was 47 μm.

[0222] Example 2 -7 (S2 -7 )

[0223] (1) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode current collector B7, wherein the modified positive electrode current collector B7 was prepared in the same manner as in Example 2. -1 The only differences are:

[0224] The modified ceramic material is modified ceramic material A7;

[0225] In the obtained modified positive electrode current collector B7, the thickness of the modified coating was 1.2 μm;

[0226] (2) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode sheet D7, wherein the modified positive electrode sheet D7 was prepared in the same manner as in Example 2. -1 The only differences are:

[0227] The modified positive electrode current collector is a modified positive electrode current collector B7;

[0228] In the obtained modified positive electrode sheet D7, the thickness of the active layer was 47 μm.

[0229] Example 2 -8 (S2 -8 )

[0230] (1) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode current collector B8, wherein the modified positive electrode current collector B8 was prepared in the same manner as in Example 2. -1 The only differences are:

[0231] The mass ratio of the conductive carbon material, the modified ceramic material and the first binder is 89:10:1;

[0232] In the obtained modified positive electrode current collector B8, the thickness of the modified coating was 1.2 μm;

[0233] (2) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode sheet D8, wherein the modified positive electrode sheet D8 was prepared in the same manner as in Example 2. -1 The only differences are:

[0234] The modified positive electrode current collector is a modified positive electrode current collector B8;

[0235] In the obtained modified positive electrode sheet D8, the thickness of the active layer was 47 μm.

[0236] Example 2 -9 (S2 -9 )

[0237] (1) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode current collector B9, wherein the modified positive electrode current collector B9 was prepared in the same manner as in Example 2. -1 The only differences are:

[0238] The mass ratio of the conductive carbon material, the modified ceramic material and the first binder is 93:6:1;

[0239] In the obtained modified positive electrode current collector B9, the thickness of the modified coating was 1.2 μm;

[0240] (2) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode sheet D9, wherein the modified positive electrode sheet D9 was prepared in the same manner as in Example 2. -1 The only differences are:

[0241] The modified positive electrode current collector is a modified positive electrode current collector B9;

[0242] In the obtained modified positive electrode sheet D9, the thickness of the active layer was 47 μm.

[0243] Example 2 -10 (S2 -10 )

[0244] (1) According to Example 2-1 (S2 -1 ) was used to prepare the modified positive electrode current collector B10, wherein the modified positive electrode current collector B10 was prepared in the same manner as in Example 2. -1 The only differences are:

[0245] The conductive carbon material is graphene;

[0246] The first binder is styrene-butadiene rubber (SBR);

[0247] The coating thickness is 3.5 μm;

[0248] In the obtained modified positive electrode current collector B10, the thickness of the modified coating was 1 μm;

[0249] (2) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode sheet D10, wherein the modified positive electrode sheet D10 was prepared in the same manner as in Example 2. -1 The only differences are:

[0250] The modified positive electrode current collector is a modified positive electrode current collector B10;

[0251] In the obtained modified positive electrode sheet D10, the thickness of the active layer was 47 μm.

[0252] Example 2 -11 (S2 -11 )

[0253] (1) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode current collector B11, wherein the modified positive electrode current collector B11 was prepared in the same manner as in Example 2. -1 The only differences are:

[0254] The conductive carbon material is carbon nanotubes;

[0255] The coating thickness is 5 μm;

[0256] In the obtained modified positive electrode current collector B11, the thickness of the modified coating was 2 μm;

[0257] (2) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode sheet D11, wherein the modified positive electrode sheet D11 was prepared in the same manner as in Example 2. -1 The only differences are:

[0258] The modified positive electrode current collector is a modified positive electrode current collector B11;

[0259] In the obtained modified positive electrode sheet D11, the thickness of the active layer was 47 μm.

[0260] Example 2 -12 (S2-12 )

[0261] (1) According to Example 2 -1 (S2 -1 ) to prepare a modified positive electrode current collector B1;

[0262] (2) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode sheet D12, wherein the modified positive electrode sheet D12 was prepared in the same manner as in Example 2. -1 The only differences are:

[0263] The mass ratio of the active material, the second binder and the conductive agent is 95:4:1;

[0264] The active material is lithium iron phosphate;

[0265] The conductive agent is conductive carbon black;

[0266] The coating thickness is 55 μm;

[0267] In the obtained modified positive electrode sheet D12, the thickness of the active layer was 41 μm.

[0268] Example 2 -13 (S2 -13 )

[0269] (1) According to Example 2 -1 (S2 -1 ) to prepare a modified positive electrode current collector B1;

[0270] (2) According to Example 2 -1 (S2 -1 ) was used to prepare the modified positive electrode sheet D13, wherein the modified positive electrode sheet D13 was prepared in the same manner as in Example 2. -1 The only differences are:

[0271] The mass ratio of the active material, the second binder and the conductive agent is 97:2:1;

[0272] The active material is LiFeMnPO4;

[0273] The conductive agent is conductive carbon;

[0274] The coating thickness is 60 μm;

[0275] In the obtained modified positive electrode sheet D13, the thickness of the active layer was 54 μm.

[0276] Comparative Example 1

[0277] A common positive electrode sheet D14 is prepared according to the following preparation method, including:

[0278] The active material, the second binder and the conductive agent are mixed uniformly in proportion to obtain an active layer slurry; the obtained active layer slurry is extrusion-coated onto the positive electrode current collector (aluminum foil), and then the coated positive electrode current collector is placed in an oven and dried at 80°C to obtain a common positive electrode sheet D14 with an active layer thickness of 47 μm; wherein,

[0279] The mass ratio of the active material, the second binder and the conductive agent is 96:3:1;

[0280] The active material is LiNi 0.6 Co 0.1 Mn 0.3 O2;

[0281] The second binder is polyvinylidene fluoride (PVDF);

[0282] The conductive agent is carbon nanotubes;

[0283] The coating thickness was 57 μm.

[0284] Modified negative electrode current collector and modified negative electrode sheet

[0285] Example 3 -1 (S3 -1 )

[0286] (1) Example 2 -1 (S2 -1 ) in step (1) by replacing the positive electrode current collector (aluminum foil) with the negative electrode current collector (copper foil) to obtain a modified negative electrode current collector C1;

[0287] In the obtained modified negative electrode current collector C1, the thickness of the modified coating was 1.2 μm;

[0288] (2) Prepare the negative positive electrode sheet D1 according to the following preparation method, including:

[0289] The active material, the second binder and the conductive agent are mixed uniformly in proportion to obtain an active layer slurry; the obtained active layer slurry is extrusion-coated on the modified negative electrode current collector, and then the coated modified negative electrode current collector is placed in an oven and dried at 80° C. to obtain a modified negative electrode sheet E1 with an active layer thickness of 47 μm; wherein,

[0290] The mass ratio of the active material, the second binder and the conductive agent is 96:3:1;

[0291] The active material is graphite;

[0292] The second binder is styrene-butadiene rubber (SBR);

[0293] The conductive agent is carbon nanotubes;

[0294] The modified negative electrode current collector is a modified negative electrode current collector C1;

[0295] The coating thickness was 57 μm.

[0296] Example 3 -2 ~3 -11 (S3 -2 ~3 -11 )

[0297] (1) Example 2 -2 ~2 -11 (S2 -2 ~2 -11 ) in step (1) are replaced by negative electrode current collectors (copper foils) to obtain modified negative electrode current collectors C2 to C11 respectively;

[0298] In the obtained modified negative electrode current collectors C2 to C9, the thickness of the modified coating was 1.2 μm;

[0299] In the obtained modified negative electrode current collector C10, the thickness of the modified coating was 1 μm;

[0300] In the obtained modified negative electrode current collector C11, the thickness of the modified coating layer was 2 μm.

[0301] (2) Example 2 -2 ~2 -11 (S2 -2 ~2 -11 ) in step (2) are replaced with modified cathode current collectors B11 to B11 respectively and in sequence with modified anode current collectors C2 to C11, and modified anode sheets E2 to E11 are obtained in sequence;

[0302] In the obtained modified negative electrode sheets E2 to E11, the thickness of the active layer was 47 μm.

[0303] Example 3 -12 (S3 -12 )

[0304] (1) According to Example 3 -1 (S3 -1 ) to prepare a modified negative electrode current collector C1;

[0305] In the obtained modified negative electrode current collector C1, the thickness of the modified coating was 1.2 μm;

[0306] (2) According to Example 3 -1 (S3 -1 ) was used to prepare the modified negative electrode sheet E12, wherein the modified negative electrode sheet E12 was prepared in the same manner as in Example 3. -1 The only differences are:

[0307] The mass ratio of the active material, the second binder and the conductive agent is 95:4:1;

[0308] The second binder is polyacrylic acid (PAA);

[0309] The conductive agent is conductive carbon black;

[0310] The coating thickness is 55 μm;

[0311] In the obtained modified negative electrode sheet E12, the thickness of the active layer was 41 μm.

[0312] Example 3 -13 (S3 -13 )

[0313] (1) According to Example 3 -1 (S3 -1 ) to prepare a modified negative electrode current collector C1;

[0314] In the obtained modified negative electrode current collector C1, the thickness of the modified coating was 1.2 μm;

[0315] (2) According to Example 3 -1 (S3 -1 ) was used to prepare the modified negative electrode sheet E13, wherein the modified negative electrode sheet E13 was prepared in the same manner as in Example 3. -1 The only differences are:

[0316] The mass ratio of the active material, the second binder and the conductive agent is 97:2:1;

[0317] The second binder is sodium carboxymethyl cellulose (CMC);

[0318] The conductive agent is conductive carbon;

[0319] The coating thickness is 60 μm;

[0320] In the obtained modified negative electrode sheet E13, the thickness of the active layer was 54 μm.

[0321] Comparative Example 2

[0322] The common negative electrode sheet E14 is prepared according to the following preparation method, including:

[0323] The active material, the second binder, and the conductive agent are mixed uniformly in proportion to obtain an active layer slurry; the obtained active layer slurry is extrusion-coated onto the negative electrode current collector (copper foil), and then the coated negative electrode current collector is placed in an oven and dried at 80°C to obtain a common negative electrode sheet E14 with an active layer thickness of 47 μm; wherein,

[0324] The mass ratio of the active material, the second binder and the conductive agent is 96:3:1;

[0325] The active material is graphite;

[0326] The second binder is styrene-butadiene rubber (SBR);

[0327] The conductive agent is carbon nanotubes;

[0328] The coating thickness was 57 μm.

[0329] Battery

[0330] Example 4 -1 ~4 -17 (S4 -1 ~S4 -17 ) and Comparative Example 3

[0331] Batteries F1 to F17 and F1' were prepared according to the following preparation method, including:

[0332] The positive electrode sheet, the separator and the negative electrode sheet are stacked in order, then wound and placed in an aluminum-plastic film, and the electrolyte is injected at 80°C, and then vacuum packaged, allowed to stand, formed, and shaped to prepare the battery; wherein,

[0333] The diaphragm used is PE;

[0334] The electrolyte used was EC / DEC / DMC+LiPF6;

[0335] The positive and negative electrodes used are shown in Table 1.

[0336] Table 1S4 -1 ~S4 -17 and the positive and negative electrodes used in Comparative Example 3 and the resulting battery

[0337] positive electrode negative electrode Battery <![CDATA[S4 -1 ]]> Modified positive electrode D1 Modified negative electrode sheet E1 Battery F1 <![CDATA[S4 -2 ]]> Modified positive electrode D2 Modified negative electrode sheet E2 Battery F2 <![CDATA[S4 -3 ]]> Modified positive electrode D3 Modified negative electrode sheet E3 Battery F3 <![CDATA[S4 -4 ]]> Modified positive electrode sheet D4 Modified negative electrode sheet E4 Battery F4 <![CDATA[S4 -5 ]]> Modified positive electrode D5 Modified negative electrode sheet E5 Battery F5 <![CDATA[S4 -6 ]]> Modified positive electrode sheet D6 Modified negative electrode sheet E6 Battery F6 <![CDATA[S4 -7 ]]> Modified positive electrode sheet D7 Modified negative electrode sheet E7 Battery F7 <![CDATA[S4 -8 ]]> Modified positive electrode sheet D8 Modified negative electrode sheet E8 Battery F8 <![CDATA[S4 -9 ]]> Modified positive electrode D9 Modified negative electrode sheet E9 Battery F9 <![CDATA[S4 -10 ]]> Modified positive electrode sheet D10 Modified negative electrode sheet E10 Battery F10 <![CDATA[S4 -11 ]]> Modified positive electrode D11 Modified negative electrode sheet E11 Battery F11 <![CDATA[S4 -12 ]]> Modified positive electrode D12 Modified negative electrode sheet E12 Battery F12 <![CDATA[S4 -13 ]]> Modified positive electrode sheet D13 Modified negative electrode sheet E13 Battery F13 <![CDATA[S4 -14 ]]> Ordinary positive electrode sheet D14 Modified negative electrode sheet E1 Battery F14 <![CDATA[S4 -15 ]]> Ordinary positive electrode sheet D14 Modified negative electrode sheet E2 Battery F15 <![CDATA[S4 -16 ]]> Modified positive electrode D1 Ordinary negative electrode sheet E14 Battery F16 <![CDATA[S4 -17 ]]> Modified positive electrode D2 Ordinary negative electrode sheet E14 Battery F17 Comparative Example 3 Ordinary positive electrode sheet D14 Ordinary negative electrode sheet E14 Battery F1'

[0338] Example 4 -1 ~4 -17 The batteries F1 to F17 and F1′ obtained in Comparative Example 3 were subjected to cycle performance tests, peeling performance tests, and battery life tests. The results are shown in Table 2.

[0339] Table 2 Example 4 -8 ~4 -17 And the performance test results of batteries F1 to F17 and F1' obtained in comparative example 3

[0340]

[0341] According to Example 4 -1 ~4 -17As can be seen from the comparison with Comparative Example 3 and Tables 1 and 2, the present invention improves the adhesion between the modified current collector and the active layer in the obtained modified electrode sheet by modifying the modified coating layer having a modified ceramic material, increases the peel strength, and makes it difficult for the modified current collector to separate from the active layer, thereby optimizing the cycle performance of the battery and extending the service life of the battery.

[0342] Example 4 -1 ~4 -2 With Example 4 -14 ~4 -15 Example 4 -16 ~4 -17 As can be seen from the comparison of comparative example 3 and Tables 1 and 2,

[0343] Compared with the comparative example 3 in which both the positive and negative electrodes are made of ordinary electrodes, the -16 ~4 -17 In the experiment, the negative electrode still uses the ordinary electrode, while the positive electrode uses the modified electrode. The peel strength of the negative electrode is not much different, and the peel strength of the positive electrode is significantly increased. The battery's cycle capacity retention rate and the number of cycles to 80% SOH are significantly improved.

[0344] Compared with the comparative example 3 in which both the positive and negative electrodes are made of ordinary electrodes, the -14 ~4 -15 In the embodiment, the positive electrode sheet still uses the ordinary electrode sheet, while the negative electrode sheet uses the modified electrode sheet. The peel strength of the positive electrode is not much different, and the peel strength of the negative electrode is significantly increased. The cycle capacity retention rate of the battery and the number of cycles to 80% SOH battery are significantly improved, and the improvement rate is greater than that of Example 4. -16 ~4 -17 The improvement is greater;

[0345] Compared with the comparative example 3 in which both the positive and negative electrodes are made of ordinary electrodes, the -1 ~4 -2 In the embodiment, the positive and negative electrodes are modified, the peel strength of the positive and negative electrodes are significantly increased, and the battery cycle capacity retention rate and the number of cycles to 80% SOH are significantly improved, and the improvement is greater than that of Example 4. -14 ~4 -15 And Example 4 -16 ~4 -17 The improvement is even greater.

Claims

1. A method for preparing a modified ceramic material, characterized in that: The preparation method comprises: (1) mixing a solvent, an acidic solution, and a silane coupling agent and allowing the mixture to stand to obtain a mixed solution; wherein the solvent is a solvent containing a hydroxyl group; (2) Adding ceramic material to the mixed solution for temperature modification to obtain modified ceramic material.

2. The method for preparing the modified ceramic material according to claim 1, wherein: The volume ratio of the solvent, the acidic solution and the silane coupling agent is (10-12):(5-6):1; and / or, The mass ratio of the ceramic material to the silane coupling agent is (25-30):1; and / or, The silane coupling agent includes any one or a combination of vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltri(β-methoxyethoxy)silane; and / or, The ceramic material comprises any one or a combination of nano-alumina, nano-silicon dioxide and nano-boehmite; and / or, The solvent includes any one or a combination of anhydrous ethanol, isopropyl alcohol, n-propyl alcohol and n-butyl alcohol; and / or, The acidic solution is any one or a combination of citric acid solution, potassium citrate solution, sodium citrate solution, lactic acid solution and tartaric acid solution; and / or, The concentration of the acidic solution is 4.5 to 8.5 g / mol; and / or, In step (1), the solvent, acid solution and silane coupling agent are mixed uniformly and then allowed to stand for 1 to 2 hours; and / or, In step (2), the modification temperature is 75-85° C., and / or the modification time is 6-8 h, and / or the temperature-raising modification is carried out under stirring in a water bath.

3. A modified ceramic material obtained according to the preparation method of claim 1 or 2.

4. A modified current collector, characterized in that: The modified current collector includes a current collector and a modified coating applied on the current collector; The modified coating comprises a conductive carbon material, the modified ceramic material according to claim 3 and a first binder.

5. The modified current collector according to claim 4, characterized in that In the modified coating, the mass ratio of the conductive carbon material, the modified ceramic material and the first binder is (89-93):(6-10):1; and / or, The conductive carbon material includes any one or a combination of nano-conductive graphite, graphene, carbon nanotubes and carbon-coated particles; and / or, The first binder includes polyvinylidene fluoride and / or styrene-butadiene rubber.

6. The modified current collector according to claim 4 or 5, characterized in that: The thickness of the modified coating is 1 to 2 μm.

7. A method for preparing the modified current collector according to any one of claims 4 to 6, characterized in that: The preparation method comprises: The conductive carbon material, the modified ceramic material according to claim 3 and the first binder are uniformly mixed in proportion to obtain a slurry of a modified coating; the obtained slurry of the modified coating is coated on a current collector, and dried to obtain a modified current collector.

8. A modified pole piece, characterized in that: The modified electrode comprises the modified current collector according to any one of claims 4 to 6 and an active layer; wherein the active layer is coated on the modified coating of the modified current collector.

9. The modified pole piece according to claim 8, characterized in that: The thickness of the active layer is 40 to 55 μm.

10. A method for preparing the modified electrode according to claim 8 or 9, characterized in that: The active material, the second binder and the conductive agent are mixed uniformly in proportion to obtain an active layer slurry; the obtained active layer slurry is extrusion-coated on the modified current collector, and then the coated modified current collector is placed in an oven for drying to obtain a modified electrode.

11. A battery, characterized in that: The battery has the modified electrode sheet according to claim 8 or 9 or the modified electrode sheet prepared by the preparation method according to claim 10.

12. A vehicle, characterized in that: The vehicle has the battery according to claim 11 .

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