Electrochemical device and electronic device

Abstract

An electrochemical device and an electronic device. The electrochemical device comprises a positive electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer arranged on at least one surface of the positive electrode current collector. The positive electrode active material layer comprises conductive particles, wherein the conductive particles comprise at least one of antimony-doped tin oxide (SnO)x1(Sb2O3)x2 or aluminum-doped zinc oxide (ZnO)y1(Al2O3)y2, with the ratio of x1:x2 ranging from 80:20 to 95:5, and the ratio of y1:y2 ranging from 85:15 to 99:1. The antimony-doped tin oxide (SnO)x1(Sb2O3)x2 and the aluminum-doped zinc oxide (ZnO)y1(Al2O3)y2 have good conductivity and a poor adsorption capacity, such that the conductivity of the conductive particles can be improved. The arrangement is beneficial for improving the conductivity of the conductive particles, thereby improving the cycle performance of the electrochemical device.

Description

Electrochemical device and electronic device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on March 12, 2024, with application number 202410282302.6 and invention name “An Electrochemical Device and Electronic Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of electrochemical technology, and in particular to an electrochemical device and an electronic device. Background Art

[0003] Lithium-ion batteries (electrochemical devices) have advantages such as high energy storage density, high open-circuit voltage, low self-discharge rate, long cycle life, and good safety. They are widely used in various fields such as portable energy storage, electronic devices, and electric vehicles. With the widespread application of lithium-ion batteries in these fields, the market has increasingly higher requirements for the electrochemical performance of lithium-ion batteries.

[0004] In the prior art, lithium-ion batteries typically use conductive carbon to improve the conductivity of the positive electrode. However, during the charge and discharge process of lithium-ion batteries, due to the strong adsorption effect of conductive carbon, side reaction products are enriched on its surface, which manifests as an increase in the diameter of the conductive carbon, affecting the conductivity of the conductive carbon and thus the cycle performance of the lithium-ion battery. Summary of the Invention

[0005] The purpose of this application is to provide an electrochemical device and an electronic device to improve the cycle performance of the electrochemical device. The specific technical solution is as follows:

[0006] The first aspect of the present application provides an electrochemical device comprising a positive electrode plate, the positive electrode plate comprising a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector, the positive electrode active material layer comprising conductive particles, the conductive particles comprising antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 At least one of the following, wherein the ratio of x1:x2 is in the range of 80:20 to 95:5, and the ratio of y1:y2 is in the range of 85:15 to 99:1. Antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 It has good conductivity and poor adsorption capacity, which can improve the conductivity of conductive particles. Conductive particles include antimony-doped tin oxide (SnO) x1 (Sb2O3) x2or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 At least one of the above and regulating the values ​​of x1:x2 and y1:y2 within the scope of the present application is beneficial to improving the conductivity of the conductive particles, thereby improving the cycle performance of the electrochemical device.

[0007] In some embodiments of the present application, antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 Located on at least part of the surface of the conductive particles, antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The ratio of the coverage area to the total surface area of ​​the conductive particles is Z, Z ≥ 50%. By regulating the antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The ratio Z of the coverage area to the total surface area of ​​the conductive particles is within the scope of the present application, which is beneficial to improving the conductivity of the conductive particles and improving the cycle performance of the electrochemical device.

[0008] In some embodiments of the present application, antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The thickness on the surface of the conductive particles is 0.5nm to 70nm. x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 When the thickness of the surface of the conductive particles is within the range of the present application, it is beneficial to improve the conductivity of the conductive particles and the cycle performance of the electrochemical device.

[0009] In some embodiments of the present application, the diameter of the conductive particles is d μm, 0.002 ≤ d ≤ 0.15, preferably 0.02 ≤ d ≤ 0.07. By regulating the diameter of the conductive particles within the scope of the present application, it is beneficial to improve the conductivity of the conductive particles and improve the cycle performance of the electrochemical device.

[0010] In some embodiments of the present application, the conductive particles are in the form of strings, and the length of the strings is L μm, with 0.05 ≤ L ≤ 5. The strings of conductive particles and the control of the string length within the scope of the present application can enhance the long-range conductivity of the conductive particles, while also facilitating the storage of electrolyte between the conductive particles, increasing the ionic conductivity of the positive electrode sheet, and further improving the cycling performance of the electrochemical device.

[0011] In some embodiments of the present application, the conductive particles have a BET specific surface area of ​​150 m 2 / g to 1000m 2 By regulating the specific surface area of ​​the strings composed of conductive particles within the scope of the present application, it is beneficial to improve the conductivity of the conductive particles and further improve the cycle performance of the electrochemical device.

[0012] In some embodiments of the present application, the interior of the conductive particles is carbon, antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 Through the above arrangement, the conductive particles can have good conductivity and improve the cycle performance of the electrochemical device.

[0013] In some embodiments of the present application, the positive electrode active material layer includes a positive electrode active material, and the particle size of the positive electrode active material satisfies at least one of the following characteristics: (1) 5 μm ≤ Dv50 ≤ 20 μm, 25 μm ≤ Dv99 ≤ 50 μm; (2) the diameter of the conductive particles is d μm, 80 ≤ Dv50 / d ≤ 6000; (3) the conductive particles are in the form of strings, and the length of the strings composed of conductive particles is L μm, 5 ≤ Dv99 / L ≤ 1000. The particle size of the positive electrode active material that satisfies at least one of the above characteristics is beneficial to the grading of the conductive particles and the positive electrode active material, improves the compaction density of the positive electrode sheet, and can enable the lithium-ion battery to have a higher energy density.

[0014] In some embodiments of the present application, the weight percentage of the conductive particles is 0.1% to 3% based on the weight of the positive electrode active material layer. By adjusting the weight percentage of the conductive particles within the range of the present application, the conductivity of the positive electrode sheet is improved, thereby improving the cycling performance of the electrochemical device.

[0015] In some embodiments of the present application, after the electrochemical device is cycled for 501 cycles at 45°C, the diameter growth rate of the conductive particles is ≤15%. This indicates that the diameter growth rate of the conductive particles is small, and the conductive particles still maintain good conductivity, thus enabling the electrochemical device to have good cycling performance.

[0016] The second aspect of the present application provides an electronic device comprising the electrochemical device provided in the first aspect of the present application. The electrochemical device provided in the first aspect of the present application has good cycle performance, so the electronic device provided in the second aspect of the present application has a long service life.

[0017] Beneficial effects of this application:

[0018] The present application provides an electrochemical device and an electronic device, wherein the electrochemical device comprises a positive electrode plate, the positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector, the positive electrode active material layer comprises conductive particles, and the conductive particles comprise antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 At least one of the following, wherein the ratio of x1:x2 is in the range of 80:20 to 95:5, and the ratio of y1:y2 is in the range of 85:15 to 99:1. Antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 It has good conductivity and poor adsorption capacity, which can improve the conductivity of conductive particles. Conductive particles include antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 At least one of the above and regulating the values ​​of x1:x2 and y1:y2 within the scope of the present application is beneficial to improving the conductivity of the conductive particles, thereby improving the cycle performance of the electrochemical device.

[0019] Of course, it is not necessary to achieve all the advantages described above at the same time when implementing any product or method of the present application. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by those skilled in the art based on the present application are within the scope of protection of the present application.

[0021] It should be noted that, in the specific embodiments of the present application, a lithium-ion battery is used as an example of an electrochemical device to explain the present application, but the electrochemical device of the present application is not limited to a lithium-ion battery.

[0022] The first aspect of the present application provides an electrochemical device comprising a positive electrode plate, the positive electrode plate comprising a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector, the positive electrode active material layer comprising conductive particles, the conductive particles comprising antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 At least one of the following, wherein the ratio of x1:x2 is in the range of 80:20 to 95:5, and the ratio of y1:y2 is in the range of 85:15 to 99:1. For example, antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 x1:x2 can be 80:20, 83:17, 85:15, 87:13, 90:10, 93:7, 95:5 or a range consisting of any two of these values; aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The ratio y1:y2 can be 85:15, 87:13, 90:10, 93:7, 95:5, 99:1 or a range consisting of any two of these values.

[0023] The researchers of this application found that antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 It has good electrical conductivity and poor adsorption capacity, which is beneficial to improving the conductivity of conductive particles, improving the accumulation of side reaction products on the surface of conductive particles, reducing the diameter growth rate of conductive particles, and also conducive to the uniform distribution of binders and conductive particles in the positive electrode sheet, thereby improving the conductivity of the positive electrode sheet and reducing the polarization of the battery cell. Conductive particles include antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 At least one of the above and regulating the values ​​of x1:x2 and y1:y2 within the scope of the present application is beneficial to improving the conductivity of the conductive particles and improving the cycle performance of the electrochemical device.

[0024] In some embodiments of the present application, antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 Located on at least part of the surface of the conductive particles, antimony-doped tin oxide (SnO) x1 (Sb2O3)x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The ratio of the coverage area to the total surface area of ​​the conductive particles is Z, and Z ≥ 50%. For example, the value of Z can be 50%, 60%, 70%, 80%, 90%, 100%, or a range consisting of any two of these values. By regulating the antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The ratio Z of the coverage area to the total surface area of ​​the conductive particles is within the scope of the present application, which is beneficial to improving the conductivity of the conductive particles, improving the accumulation of side reaction products on the surface of the conductive particles, reducing the polarization of the battery cell, and improving the cycle performance of the electrochemical device.

[0025] In some embodiments of the present application, antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The thickness on the surface of the conductive particles is 0.5nm to 70nm. For example, antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The thickness on the surface of the conductive particles can be 0.5nm, 1nm, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm or a range consisting of any two of these values. x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 When the thickness of the surface of the conductive particles is within the range of the present application, it is beneficial to improve the conductivity of the conductive particles and the cycle performance of the electrochemical device.

[0026] In some embodiments of the present application, the diameter of the conductive particles is d μm, 0.002 ≤ d ≤ 0.15, preferably 0.02 ≤ d ≤ 0.07. For example, the diameter of the conductive particles can be 0.002 μm, 0.01 μm, 0.02 μm, 0.03 μm, 0.04 μm, 0.05 μm, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm, 0.1 μm, 0.12 μm, 0.14 μm, 0.15 μm, or a range consisting of any two of these values. By regulating the diameter of the conductive particles within the scope of the present application, it is beneficial to improve the conductivity of the conductive particles and improve the cycle performance of the electrochemical device.

[0027] In some embodiments of the present application, the conductive particles are in the form of strings, and the length of the strings composed of the conductive particles is Lμm, 0.05≤L≤5. For example, the length of the strings composed of the conductive particles can be 0.05μm, 0.5μm, 1μm, 2μm, 3μm, 4μm, 5μm or a range consisting of any two of these values. The conductive particles are in the form of strings and the length of the strings is regulated within the scope of the present application, which can enable the conductive particles to play a long-range conductive role, improve the conductivity of the conductive particles, and at the same time be beneficial to the storage of the electrolyte between the conductive particles, which is beneficial to the active metal ions (such as Li + ) transmission, improve the ionic conductivity of the positive electrode sheet, and further improve the cycle performance of the electrochemical device. In this application, the conductive particles are in the form of strings, which means that multiple conductive particles are connected to form a string.

[0028] In some embodiments of the present application, the conductive particles have a BET specific surface area of ​​150 m 2 / g to 1000m 2 / g, for example, the specific surface area of ​​the string composed of conductive particles can be 150m 2 / g、300m 2 / g、350m 2 / g, 400m 2 / g, 450m 2 / g、500m 2 / g、550m 2 / g、600m 2 / g、800m 2 / g、900m 2 / g、1000m 2 By regulating the specific surface area of ​​the strings composed of conductive particles within the scope of the present application, the conductivity of the conductive particles is improved, and the cycle performance of the electrochemical device is further improved.

[0029] In some embodiments of the present application, the interior of the conductive particles is carbon, antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The above configuration can provide the conductive particles with good electrical conductivity, thereby improving the cycle performance of the electrochemical device. The carbon element comprises at least one of graphene, Ketjen black, or conductive carbon black (Super P).

[0030] In some embodiments of the present application, the positive electrode active material layer includes a positive electrode active material, and the particle size of the positive electrode active material satisfies at least one of the following characteristics: (1) 5 μm ≤ Dv50 ≤ 20 μm, 25 μm ≤ Dv99 ≤ 50 μm; (2) the diameter of the conductive particles is d μm, 80 ≤ Dv50 / d ≤ 6000; Dv50 is the Dv50 of the positive electrode active material, in μm; (3) the conductive particles are in the form of strings, the length of the strings composed of the conductive particles is L μm, 5 ≤ Dv99 / L ≤ 1000, and Dv99 is the Dv99 of the positive electrode active material, in μm. The particle size of the positive electrode active material that satisfies at least one of the above characteristics is beneficial to the grading of the conductive particles and the positive electrode active material, improves the compaction density of the positive electrode sheet, can make the lithium ion battery have a higher energy density, and is beneficial to exerting the conductivity of the conductive particles and improving the cycle performance of the lithium ion battery. "Dv50" refers to the particle size at which 50% of the volume is accumulated, measured from the smallest particle size, in the volume-based particle size distribution of the material. "Dv99" refers to the particle size at which 99% of the volume is accumulated, measured from the smallest particle size, in the volume-based particle size distribution of the material.

[0031] In some embodiments of the present application, the weight percentage of the conductive particles is 0.1% to 3% based on the weight of the positive electrode active material layer. For example, the weight percentage of the conductive particles can be 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, or a range consisting of any two of these values. By regulating the weight percentage of the conductive particles within the range of the present application, the conductivity of the positive electrode sheet is improved, thereby improving the cycling performance of the electrochemical device.

[0032] In some embodiments of the present application, after the electrochemical device is cycled for 501 cycles at 45°C, the diameter growth rate of the conductive particles is ≤15%. This indicates that the diameter growth rate of the conductive particles is small, the conductive particles still maintain good conductivity, and that the electrochemical device has good cycling performance.

[0033] In some embodiments of the present application, after the electrochemical device is cycled at 45° C. for 501 cycles, the capacity retention rate of the electrochemical device is ≥80%, indicating that the electrochemical device has good cycle performance.

[0034] The present application does not particularly limit the preparation method of the conductive particles, as long as the purpose of the present application can be achieved. For example, the preparation method of the conductive particles with carbon elements inside may include but is not limited to the following steps: first, the hydrocarbon substance is pyrolyzed and purified under high temperature conditions to obtain high-purity nano conductive carbon particles. The above-mentioned hydrocarbon substance may include but is not limited to at least one of acetylene or methane. Commercially available conductive carbon particles can also be used. Nano conductive carbon particles are used as a carbon source, dissolved in water with metal salts, oxidants, precipitants, surfactants, etc. to form an aqueous solution, and the aqueous solution is transferred to a hydrothermal kettle, sealed, and allowed to react at a certain temperature and pressure for a period of time, and then filtered, washed, and calcined to obtain conductive particles with carbon elements inside, and then sintered at high temperature to obtain conductive particles in the form of strings. The interior of the conductive particles is antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The preparation method may include but is not limited to the following steps: dissolving a metal salt, an oxidant, a precipitant, a surfactant, etc. in water to form an aqueous solution, transferring the aqueous solution to a hydrothermal kettle, sealing it, allowing it to react for a period of time at a certain temperature and pressure, and then filtering, washing, and calcining it to obtain antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The conductive particles are then sintered at high temperature to obtain conductive particles in the form of strings.

[0035] Synthesis (SnO) x1 (Sb2O3) x2 The metal salts include tin salts and antimony salts. Tin salts may include but are not limited to at least one of tin dichloride, tin nitrate, and tin sulfate. Antimony salts may include but are not limited to at least one of antimony trichloride, antimony nitrate, and antimony sulfate. Synthesis (ZnO) y1 (Al2O3) y2 The metal salts include zinc salts and aluminum salts. The zinc salts may include, but are not limited to, at least one of zinc dichloride, zinc sulfate, and zinc acetate. The aluminum salts may include, but are not limited to, at least one of aluminum trichloride, aluminum nitrate, and aluminum sulfate. The oxidant may include, but are not limited to, at least one of nitric acid and hydrogen peroxide. The precipitant may include, but are not limited to, at least one of ammonium hydroxide and sodium hydroxide. The surfactant may include, but are not limited to, at least one of sodium nitrate and sodium lauryl sulfate.

[0036] The present application has no particular restrictions on the temperature of the reaction in the hydrothermal kettle, the pressure of the reaction in the hydrothermal kettle, the time of the reaction in the hydrothermal kettle, the calcination temperature, the calcination time, the high-temperature sintering temperature, and the high-temperature sintering time, as long as the purpose of the present application can be achieved. For example, the temperature of the reaction in the hydrothermal kettle can be 100°C to 200°C, the pressure of the reaction in the hydrothermal kettle can be 1MPa to 5MPa, the time of the reaction in the hydrothermal kettle can be 3h to 10h, the calcination temperature can be 130°C to 250°C, the calcination time can be 22h to 26h, the high-temperature sintering temperature can be 700°C to 1100°C, and the high-temperature sintering time can be 1h to 5h.

[0037] The present application has no particular restrictions on the positive electrode sheet, as long as the purpose of the present application can be achieved. For example, the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector. The present application has no particular restrictions on the positive electrode current collector, as long as the purpose of the present application can be achieved. For example, the positive electrode current collector may include aluminum foil or aluminum alloy foil, etc. The positive electrode active material layer of the present application includes a positive electrode active material. The present application has no particular restrictions on the type of positive electrode active material, as long as the purpose of the present application can be achieved. For example, the positive electrode active material may include at least one of lithium nickel cobalt manganese oxide (NCM811, NCM622, NCM523, NCM111), lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium-rich manganese-based material, lithium cobalt oxide (LiCoO2), lithium manganese oxide, lithium iron manganese phosphate, or lithium titanate, preferably at least one of lithium nickel cobalt manganese oxide (NCM811, NCM622, NCM523, NCM111), lithium cobalt oxide (LiCoO2), and lithium manganese oxide. Based on the mass of the positive electrode active material layer, the mass percentage of the positive electrode active material can be 93% to 99%, for example, the mass percentage of the positive electrode active material is 93%, 94%, 95%, 96%, 97%, 98%, 99% or a range consisting of any two values ​​therein. In the present application, there is no particular restriction on the thickness of the positive electrode current collector and the positive electrode active material layer, as long as the purpose of the present application can be achieved. For example, the thickness of the positive electrode current collector is 5μm to 20μm, preferably 6μm to 18μm. The thickness of the single-sided positive electrode active material layer is 30μm to 120μm. In the present application, the positive electrode active material layer can be arranged on one surface in the thickness direction of the positive electrode current collector, or on two surfaces in the thickness direction of the positive electrode current collector. It should be noted that the "surface" here can be the entire area of ​​the positive electrode current collector or a partial area of ​​the positive electrode current collector. There is no particular restriction in the present application, as long as the purpose of the present application can be achieved. The positive electrode active material layer of the present application may further include a positive electrode conductive agent and a positive electrode binder. The present application has no particular restrictions on the positive electrode conductive agent and the positive electrode binder, as long as the purpose of the present application can be achieved. For example, the conductive agent may include at least one of graphene, carbon nanotubes, Ketjen black, graphite fiber, or conductive carbon black (Super P). Based on the mass of the positive electrode active material layer, the mass percentage of the positive electrode conductive agent may be 0.1% to 3%, for example, the mass percentage of the positive electrode conductive agent is 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, or a range consisting of any two of these values.The positive electrode binder may include at least one of polyacrylic acid, polyvinylidene fluoride (PVDF), polytetrafluoroethylene-hexafluoropropylene, sodium polyacrylate, nitrile rubber, or polyacrylate. Based on the mass of the positive electrode active material layer, the mass percentage content of the positive electrode binder may be 0.5% to 4%. For example, the mass percentage content of the positive electrode binder is 0.5%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, or a range composed of any two of these values.

[0038] This application has no particular limitation on the negative electrode sheet, as long as the purpose of this application can be achieved. For example, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer provided on at least one surface of the negative electrode current collector. In this application, the negative electrode active material layer may be provided on one surface in the thickness direction of the negative electrode current collector, or may be provided on both surfaces in the thickness direction of the negative electrode current collector. It should be noted that the "surface" here may be the entire area of the negative electrode current collector or a partial area of the negative electrode current collector. This application has no particular limitation, as long as the purpose of this application can be achieved. This application has no particular limitation on the negative electrode current collector, as long as the purpose of this application can be achieved. For example, the negative electrode current collector may include, but is not limited to, copper foil, copper alloy foil, nickel foil, titanium foil, nickel foam, copper foam, or composite current collector, etc. The negative electrode active material layer of this application contains a negative electrode active material. This application has no particular limitation on the type of the negative electrode active material, as long as the purpose of this application can be achieved. For example, the negative electrode active material may include, but is not limited to, natural graphite, artificial graphite, mesocarbon microbeads (MCMB), hard carbon, soft carbon, silicon, silicon-carbon composite, SiO x (0 < x ≤ 2) or at least one of metallic lithium, etc. In this application, there is no particular limitation on the thickness of the negative electrode current collector and the negative electrode active material layer, as long as the purpose of this application can be achieved. For example, the thickness of the negative electrode current collector is 4 μm to 12 μm, and the thickness of the single-sided negative electrode active material layer is 30 μm to 130 μm. The negative electrode active material layer of this application may also contain a conductive agent and a binder. This application has no particular limitation on the conductive agent and the binder, as long as the purpose of this application can be achieved. For example, the conductive agent may include at least one of conductive carbon black (Super P), carbon nanotubes (CNTs), carbon nanofibers, graphite fibers, Ketjen black, acetylene black, natural graphite, artificial graphite, flake graphite, or graphene, etc. The binder may include at least one of polyacrylic acid, polyvinyl alcohol, polyacrylate, sodium polyacrylate, potassium polyacrylate, lithium polyacrylate, polyimide, polyamideimide, nitrile rubber, styrene-butadiene rubber (SBR), polyvinyl alcohol (PVA), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polytetrafluoroethylene-hexafluoropropylene, polyvinyl butyral (PVB), water-based acrylic resin, carboxymethyl cellulose (CMC), or sodium carboxymethyl cellulose (CMC-Na), etc.

[0039] The electrochemical device of the present application also includes an electrolyte, and the electrolyte may include a lithium salt and an organic solvent. The present application has no particular restrictions on the type of lithium salt, as long as the purpose of the present application can be achieved. For example, the lithium salt may include but is not limited to lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium difluorophosphate (LiPO2F2), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(oxalatoborate) (LiBOB) or lithium difluorooxalatoborate (LiDFOB). The present application does not limit the content of lithium salt in the electrolyte, as long as the purpose of the present application can be achieved. The present application has no particular restrictions on the type of the above-mentioned organic solvent, as long as the purpose of the present application can be achieved. For example, it may include but is not limited to at least one of a carbonate compound, a carboxylate compound, an ether compound or other organic solvents. The above-mentioned carbonate compound may include but is not limited to at least one of a chain carbonate compound or a cyclic carbonate compound. The above-mentioned linear carbonate compound may include but is not limited to at least one of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate or methylethyl carbonate. The above-mentioned cyclic carbonate compound may include but is not limited to at least one of ethylene carbonate, propylene carbonate, butylene carbonate or vinylethylene carbonate. The above-mentioned carboxylate compound may include but is not limited to at least one of methyl formate, methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, γ-butyrolactone, decanoic acid, valerolactone or caprolactone. The above-mentioned ether compound may include but is not limited to at least one of ethylene glycol dimethyl ether, dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1-ethoxy-1-methoxyethane, 2-methyltetrahydrofuran or tetrahydrofuran. The above-mentioned other organic solvents may include but are not limited to at least one of dimethyl sulfoxide, 1,2-dioxolane, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, dimethylformamide, acetonitrile, trimethyl phosphate, triethyl phosphate or trioctyl phosphate.

[0040] The electrochemical device of the present application also includes a diaphragm to separate the positive electrode sheet and the negative electrode sheet, prevent internal short circuit of the electrochemical device, allow electrolyte ions to pass freely, and do not affect the electrochemical charge and discharge process. The present application has no special restrictions on the diaphragm, as long as the purpose of the present application can be achieved. For example, the material of the diaphragm may include but is not limited to polyethylene (PE), polypropylene (PP), polytetrafluoroethylene-based polyolefin (PO) diaphragms, polyester films (such as polyethylene terephthalate (PET) films), cellulose films, polyimide films (PI), polyamide films (PA), spandex or aramid films, etc. At least one of the following. The type of diaphragm may include but is not limited to at least one of a woven membrane, a non-woven membrane (non-woven fabric), a microporous membrane, a composite membrane, a rolled membrane or a spun membrane, etc. The diaphragm of the present application may have a porous structure, and the porous layer is provided on at least one surface of the diaphragm, and the porous layer includes inorganic particles and a binder. The inorganic particles may include at least one of aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, cerium dioxide, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide or barium sulfate. The binder may include at least one of polyvinylidene fluoride, a copolymer of vinylidene fluoride and hexafluoropropylene, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, sodium carboxymethyl cellulose, polyvinyl pyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene or polyhexafluoropropylene. The present application does not particularly limit the size of the pore size of the porous structure, as long as the purpose of the present application can be achieved, for example, the size of the pore size can be 0.01 μm to 1 μm. In the present application, the thickness of the diaphragm is not particularly limited, as long as the purpose of the present application can be achieved, for example, the thickness can be 3 μm to 500 μm.

[0041] The electrochemical device of the present application also includes a packaging bag for containing the positive electrode sheet, separator, negative electrode sheet, and electrolyte, as well as other components of the electrochemical device known in the art. This application does not limit these other components. This application does not particularly limit the packaging bag and can be any packaging bag known in the art, as long as it can achieve the purpose of this application. For example, an aluminum-plastic film packaging bag can be used.

[0042] The electrochemical device of the present application is not particularly limited and may include any device that undergoes an electrochemical reaction. In one embodiment of the present application, the electrochemical device may include, but is not limited to, a lithium-ion battery, a sodium-ion battery, a lithium polymer secondary battery, or a lithium-ion polymer secondary battery.

[0043] The preparation process of the electrochemical device of the present application is well known to those skilled in the art and is not particularly limited in the present application. For example, it may include but is not limited to the following steps: stacking the positive electrode sheet, the separator and the negative electrode sheet in order, and winding, folding and other operations as needed to obtain an electrode assembly with a wound structure, placing the electrode assembly in a packaging bag, injecting an electrolyte into the packaging bag and sealing it to obtain an electrochemical device; or stacking the positive electrode sheet, the separator and the negative electrode sheet in order, and then fixing the four corners of the entire stacked structure with tape to obtain an electrode assembly with a stacked structure, placing the electrode assembly in a packaging bag, injecting an electrolyte into the packaging bag and sealing it to obtain an electrochemical device. In addition, an overcurrent protection element, a guide plate, etc. may also be placed in the packaging bag as needed to prevent pressure rise and overcharging and discharging inside the electrochemical device.

[0044] The second aspect of the present application provides an electronic device, which includes the electrochemical device provided by the first aspect of the present application. The electrochemical device provided by the present application has good cycle performance, so the electronic device provided by the present application has a long service life.

[0045] The electronic device of the present application is not particularly limited and can be any electronic device known in the art. In some embodiments, the electronic device can include, but is not limited to, a laptop computer, a pen-type computer, a mobile computer, an e-book player, a portable phone, a portable fax machine, a portable copier, a portable printer, a headset, a video recorder, an LCD television, a portable cleaner, a portable CD player, a mini-disc, a transceiver, an electronic notepad, a calculator, a memory card, a portable recorder, a radio, a backup power supply, a motor, an automobile, a motorcycle, a power-assisted bicycle, a bicycle, a lighting fixture, a toy, a game console, a clock, a power tool, a flashlight, a camera, a large household battery or a lithium-ion capacitor, etc.

[0046] Example

[0047] The following examples and comparative examples are provided to more specifically illustrate the embodiments of the present invention. Various tests and evaluations were performed according to the following methods. In addition, unless otherwise specified, "parts" and "%" are based on mass.

[0048] Test methods and equipment:

[0049] Test of various characteristic quantities of conductive particles

[0050] (1) The lithium-ion battery was disassembled to obtain the positive electrode sheet, which was then soaked in dimethyl carbonate (DMC) at 25±5°C for 30 min and then taken out and naturally dried.

[0051] (2) The positive electrode obtained in (1) was observed and tested using a scanning electron microscope (instrument model: ZEISSSEM) to measure the diameter of 15 conductive particles and the length of the string composed of 15 conductive particles. The average values ​​were recorded as the diameter d of the conductive particles and the length L of the string composed of the conductive particles. The surface elements of the positive electrode were tested using EDS. The obtained Sn element content was x1, 1 / 2 of the Sb element content was x2, the Zn element content was y1, and 1 / 2 of the Al element content was y2.

[0052] (3) The positive electrode sheet obtained in (1) was cut under plasma to obtain a cross section of the positive electrode sheet, and the internal elements of the conductive particles and antimony-doped tin oxide (SnO) at 15 locations were observed and tested under a scanning electron microscope. x1 (Sb2O3) x2 / Aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The coverage and thickness on the surface of the conductive particles are averaged and recorded as antimony-doped tin oxide (SnO). x1 (Sb2O3) x2 / Aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The coverage Z and thickness of the conductive particles. Antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 / Aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The coverage on the surface of the conductive particles is the result of testing using statistical software.

[0053] BET test of specific surface area of ​​conductive particles

[0054] The specific surface area of ​​the conductive particles was measured using a Tristar II 3020M surface area analyzer using nitrogen adsorption. The specific test was conducted in accordance with the national standard GB / T 19587-2017, "Determination of the Specific Surface Area of ​​Solids by the BET Method for Gas Adsorption."

[0055] Testing of particle size of positive electrode active materials

[0056] (1) The lithium-ion battery was disassembled to obtain the positive electrode sheet, which was then soaked in dimethyl carbonate (DMC) at 25±5°C for 30 min and then taken out and naturally dried.

[0057] (2) The positive electrode sheet obtained in (1) is placed in concentrated sulfuric acid for corrosion, and the remaining particles are the positive electrode active material.

[0058] (3) The positive electrode active material particles obtained in (2) were washed with deionized water and stirred and dispersed, and then tested using a Malvern laser particle size analyzer to obtain Dv50 and Dv99 of the positive electrode active material.

[0059] Cycle performance test

[0060] The lithium-ion battery was placed at 45°C for 60 minutes, then discharged at a constant current of 0.5C to 3V and allowed to stand for 5 minutes.

[0061] {

Charge to 4.5V at 1.5C constant current, then charge to 0.05C at 4.5V constant voltage, let stand for 5 minutes, then discharge to 3V at 0.7C constant current, let stand for 5 minutes

[0062] The process in [ ] is cycled 49 times, and the battery discharge capacity is recorded as C1, C2, C3….C 49 At the 50th week, the battery was charged to 4.5V at a constant current of 0.5C, then charged to 0.05C at a constant voltage of 4.5V, left to stand for 5 minutes, and then discharged to 3V at a constant current of 0.2C. The discharge capacity of the lithium-ion battery was recorded. 50}

[0063] Cycle the process in {} 10 times, then cycle the process in [] once, and record the discharge capacity of the lithium-ion battery at this time as C 501 , the capacity retention rate of lithium-ion battery after 501 cycles = C 501 / C1×100%.

[0064] Conductive particle diameter growth rate test

[0065] Disassemble the unused lithium-ion battery, remove the positive electrode sheet, clean it with dimethyl carbonate (DMC), and use a scanning electron microscope (instrument model is ZEISSSEM) to observe and test the diameters of 50 conductive particles, calculate the average value, and record it as d0; take the lithium-ion battery under the same conditions to test the above cycle performance, and disassemble the lithium-ion battery after 501 cycles at 45°C, remove the positive electrode sheet, clean it with DMC, and use a scanning electron microscope to observe and test the diameters of 50 conductive particles, calculate the average value, and record it as d 501 , conductive particle diameter growth rate = [(d 501 -d0) / d0]×100%.

[0066] Example 1

[0067] <Preparation of positive electrode sheet>

[0068] The positive electrode active material lithium cobalt oxide (LiCoO2), the positive electrode binder polyvinylidene fluoride (PVDF), the conductive particles, and the positive electrode conductive agent carbon nanotubes (CNT) are mixed in a mass ratio of 97.8:1.2:0.5:0.5, wherein the Dv50 of the positive electrode active material is 12 μm, the Dv99 of the positive electrode active material is 30 μm, the conductive particle diameter d is 0.03 μm, the conductive particle string length L is 1 μm, and the BET of the conductive particle string is 453 m 2 / g, (SnO) x1 (Sb2O3) x2 The thickness on the surface of the conductive particles is 6nm, where x1:x2=90:10. Then N-methylpyrrolidone (NMP) is added as a solvent to prepare a slurry with a solid content of 75wt%, and stirred evenly. The positive electrode slurry is evenly coated on one surface of a positive electrode current collector aluminum foil with a thickness of 10μm, and dried at 110°C to obtain a positive electrode sheet with a single-sided positive electrode active material coating and a positive electrode active material layer thickness of 60μm. Thereafter, the above steps are repeated on the other surface of the positive electrode sheet to obtain a positive electrode sheet with a double-sided positive electrode active material coating. After coating, the positive electrode sheet is cold pressed and cut into sheets with a specification of 74mm×867mm for standby use.

[0069] <Preparation of negative electrode sheet>

[0070] The negative electrode active materials, graphite, styrene-butadiene rubber, and sodium carboxymethyl cellulose, were mixed in a mass ratio of 97.5:1.3:1.2. Deionized water was then added as a solvent to create a negative electrode slurry with a solids content of 70 wt%, which was then stirred thoroughly. The negative electrode slurry was evenly coated on one surface of a 6 μm thick copper foil, dried at 95°C, and cold pressed to produce a 120 μm thick negative electrode sheet coated on one side with the negative electrode active material layer. The negative electrode sheet was cut into 74 mm x 875 mm sheets for later use.

[0071] <Preparation of Separator>

[0072] A polyethylene film with a thickness of 5 μm (supplied by Celgard) was used.

[0073] <Preparation of Electrolyte>

[0074] In a dry argon atmosphere glove box, organic solvents ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed in a mass ratio of 30:50:20, and then lithium salt LiPF6 was added to the organic solvent to dissolve and mix evenly to obtain an electrolyte with a lithium salt concentration of 1.15 mol / L.

[0075] <Preparation of lithium-ion batteries>

[0076] The positive electrode sheet, separator, and negative electrode sheet are stacked in order, with the separator positioned between the positive and negative electrodes to provide insulation. The electrodes are then wound to form an electrode assembly. The electrode assembly is then placed in an aluminum-plastic film packaging bag, dehydrated at 80°C, and then injected with the aforementioned electrolyte and packaged. The lithium-ion battery is then produced through a series of processes, including formation, degassing, and shaping.

[0077] Example 2 to Example 22

[0078] Except for adjusting the parameters of the conductive particles according to Table 1 in the "Preparation of Positive Electrode Sheet", the rest is the same as Example 1.

[0079] Example 23

[0080] In addition to adjusting the parameters of the conductive particles according to Table 1 in the preparation of the positive electrode sheet, the conductive particles are (SnO) x1 (Sb2O3) x2 Except for (ATO), the rest is the same as that of Example 1.

[0081] Example 24

[0082] In addition to adjusting the parameters of the conductive particles according to Table 1 in the preparation of the positive electrode sheet, the conductive particles are (ZnO) y1 (Al2O3) y2 Except for (AZO), the rest is the same as in Example 1.

[0083] Example 25 to Example 28

[0084] Except for adjusting the relevant parameters in Table 1 in the preparation of the positive electrode sheet, the rest is the same as in Example 1.

[0085] Example 29 to Example 30

[0086] Except that the mass percentage of the conductive particles in <Preparation of Positive Electrode Sheet> is adjusted according to Table 1, and the mass percentage of the positive electrode active material is changed accordingly, the rest is the same as Example 1.

[0087] Comparative Example 1

[0088] Except that conductive carbon is used as the conductive particles in the preparation of the positive electrode sheet, the rest is the same as that in Example 1.

[0089] The researchers of this application found that antimony-doped tin oxide (SnO) in conductive particles x1 (Sb2O3) x2 x1:x2 and aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2The value of y1:y2 will affect the cycle performance of the lithium-ion battery. From Examples 1 to 6 and Comparative Example 1, it can be seen that the conductive particles include antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 At least one of them, and regulating the values ​​of x1:x2 and y1:y2 within the scope of this application, is beneficial to improving the conductivity of the conductive particles, and can make the lithium-ion battery have a lower conductive particle diameter growth rate and a higher capacity retention rate, indicating that the lithium-ion battery has good cycle performance.

[0090] The researchers of this application found that antimony-doped tin oxide (SnO) in conductive particles x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The ratio Z of the coverage area to the total surface area of ​​the conductive particles will affect the cycle performance of the lithium-ion battery.

[0091] It can be seen from Examples 1, 4, 7 to 10 that by regulating the antimony-doped tin oxide (SnO) in the conductive particles x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The ratio Z of the coverage area to the total surface area of ​​the conductive particles is within the scope of the present application, which is beneficial to improving the conductivity of the conductive particles and can enable the lithium-ion battery to have a lower conductive particle diameter growth rate and a higher capacity retention rate, indicating that the lithium-ion battery has good cycle performance.

[0092] The researchers of this application found that antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The thickness of the conductive particles on the surface will affect the cycle performance of the lithium-ion battery. From Examples 1, 4, 11 to 13, and 14 to 16, it can be seen that by adjusting the antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 When the thickness of the conductive particle surface is within the range of this application, it is beneficial to improve the conductivity of the conductive particles, and can make the lithium-ion battery have a lower conductive particle diameter growth rate and a higher capacity retention rate, indicating that the lithium-ion battery has good cycle performance.

[0093] The researchers of this application found that the diameter d value of the conductive particles affects the cycle performance of the lithium-ion battery. It can be seen from Examples 1 and 17 to 19 that by regulating the diameter d value of the conductive particles within the scope of this application, it is beneficial to improve the conductivity of the conductive particles, and the lithium-ion battery can have a lower conductive particle diameter growth rate and a higher capacity retention rate, indicating that the lithium-ion battery has good cycle performance.

[0094] The researchers of this application found that the length L of the strings formed by the conductive particles affects the cycle performance of the lithium-ion battery. It can be seen from Examples 1 and 20 to 22 that by regulating the length L of the strings formed by the conductive particles within the scope of this application, it is beneficial to improve the conductivity of the conductive particles, and the lithium-ion battery can have a lower conductive particle diameter growth rate and a higher capacity retention rate, indicating that the lithium-ion battery has good cycle performance.

[0095] The researchers of this application found that the specific surface area BET of the strings composed of conductive particles will affect the cycle performance of the lithium-ion battery. From Examples 1 to 30, it can be seen that by regulating the specific surface area BET of the strings composed of conductive particles within the scope of this application, it is beneficial to improve the conductivity of the conductive particles, and the lithium-ion battery can have a lower conductive particle diameter growth rate and a higher capacity retention rate, indicating that the lithium-ion battery has good cycle performance.

[0096] The researchers of this application found that the internal material of the conductive particles will affect the cycle performance of the lithium-ion battery. From Examples 1, 4, 23 to 24, it can be seen that the internal material of the conductive particles is carbon, antimony-doped tin oxide (SnO), x1 (Sb2O3) x2 or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 One of them is beneficial to improving the conductivity of the conductive particles, which can make the lithium-ion battery have a lower conductive particle diameter growth rate and a higher capacity retention rate, indicating that the lithium-ion battery has good cycle performance.

[0097] The researchers of this application found that the particle size Dv50 of the positive electrode active material affects the cycle performance of the lithium-ion battery. It can be seen from Examples 1 and 25 to 26 that by regulating the particle size Dv50 of the conductive particle positive electrode active material within the scope of this application, the lithium-ion battery can have a lower conductive particle diameter growth rate and a higher capacity retention rate, indicating that the lithium-ion battery has good cycle performance.

[0098] The researchers of this application found that the particle size Dv99 of the positive electrode active material affects the cycle performance of the lithium-ion battery. It can be seen from Example 1, Example 27 to Example 28 that by regulating the particle size Dv99 of the conductive particle positive electrode active material within the scope of this application, the lithium-ion battery can have a lower conductive particle diameter growth rate and a higher capacity retention rate, indicating that the lithium-ion battery has good cycle performance.

[0099] The researchers of this application found that the mass percentage of the conductive particles in the positive electrode active material layer affects the cycle performance of the lithium-ion battery. It can be seen from Examples 1 and 29 to 30 that by regulating the mass percentage of the conductive particles in the positive electrode active material layer within the scope of this application, the lithium-ion battery can have a lower conductive particle diameter growth rate and a higher capacity retention rate, indicating that the lithium-ion battery has good cycle performance.

[0100] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. An electrochemical device comprising a positive electrode plate, the positive electrode plate comprising a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector, the positive electrode active material layer comprising conductive particles, the conductive particles comprising antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 At least one of The ratio of x1:x2 ranges from 80:20 to 95:5, and the ratio of y1:y2 ranges from 85:15 to 99:

1.

2. The electrochemical device according to claim 1, wherein The antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 Located on at least a portion of the surface of the conductive particles, the antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The ratio of the coverage area to the total surface area of ​​the conductive particles is Z, and Z is ≥ 50%.

3. The electrochemical device according to claim 1, wherein The antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 and / or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 The thickness on the surface of the conductive particles is 0.5 nm to 70 nm.

4. The electrochemical device according to claim 1, wherein The diameter of the conductive particles is d μm, 0.002≤d≤0.

15.

5. The electrochemical device according to claim 1, wherein The diameter of the conductive particles is d μm, 0.02≤d≤0.

07.

6. The electrochemical device according to claim 1, wherein The conductive particles are in the form of strings, and the length of the strings composed of the conductive particles is L μm, and 0.05≤L≤5.

7. The electrochemical device according to claim 6, wherein The BET specific surface area of ​​the string composed of the conductive particles is 150 m 2 / g to 1000m 2 / g.

8. The electrochemical device according to claim 1, wherein The interior of the conductive particles is carbon, antimony-doped tin oxide (SnO) x1 (Sb2O3) x2 or aluminum-doped zinc oxide (ZnO) y1 (Al2O3) y2 .

9. The electrochemical device according to claim 1, wherein The positive electrode active material layer includes a positive electrode active material, and the particle size of the positive electrode active material satisfies at least one of the following characteristics: (1) 5μm≤Dv50≤20μm, 25μm≤Dv99≤50μm; (2) The diameter of the conductive particles is d μm, 80≤Dv50 / d≤6000; (3) The conductive particles are in the form of strings, and the length of the strings composed of the conductive particles is L μm, and 5≤Dv99 / L≤1000.

10. The electrochemical device according to claim 1, wherein The conductive particles may have a content in an amount of 0.1% to 3% by mass based on the mass of the positive electrode active material layer.

11. An electronic device comprising the electrochemical device according to any one of claims 1 to 10.

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