WO2023184234A1

WO2023184234A1 - Electrochemical device and electronic device

Info

Publication number: WO2023184234A1
Application number: PCT/CN2022/084053
Authority: WO
Inventors: 韩冬冬; 刘晓欠; 张青文
Original assignee: 宁德新能源科技有限公司
Priority date: 2022-03-30
Filing date: 2022-03-30
Publication date: 2023-10-05
Also published as: CN117043977A

Abstract

Disclosed in the present application is an electrochemical device. The electrochemical device comprises: a positive electrode which comprises a positive electrode current collector, a protective layer and a positive electrode active material layer. The protective layer is arranged between the positive electrode current collector and the positive electrode active material layer. The protective layer comprises inorganic particles. By using a laser particle size analyzer for testing, the inorganic particles satisfy Dv5≤0.5 μm, wherein Dv5 represents the corresponding particle size when the cumulative volume distribution number of the inorganic particles reaches 5%, such that the electrochemical device can have good safety.

Description

一种电化学装置及电子装置An electrochemical device and an electronic device

技术领域Technical field

本申请涉及储能领域，具体涉及一种电化学装置及电子装置。This application relates to the field of energy storage, and specifically to an electrochemical device and an electronic device.

背景技术Background technique

随着电子产品如笔记本电脑、手机、掌上游戏机和平板电脑等的普及，人们对电化学装置(例如，锂离子电池)的安全性要求也越来越严格。目前，锂离子电池在使用过程中，仍然存在由于外力撞击或挤压等原因造成的着火、***等安全事故，阻碍了锂离子电池的广泛应用。其中，正极集流体与负极活性材料层之间的短路是最容易导致事故的一种。因此，亟需一种能够改善锂离子电池安全性能的技术手段。With the popularity of electronic products such as laptops, mobile phones, handheld game consoles, and tablet computers, safety requirements for electrochemical devices (such as lithium-ion batteries) are becoming more and more stringent. At present, during the use of lithium-ion batteries, there are still safety accidents such as fires and explosions caused by external impacts or extrusions, which hinders the widespread application of lithium-ion batteries. Among them, the short circuit between the positive electrode current collector and the negative electrode active material layer is the most likely to cause accidents. Therefore, a technical means that can improve the safety performance of lithium-ion batteries is urgently needed.

发明内容Contents of the invention

根据本申请的一方面，本申请提供一种电化学装置，其包括：正极，所述正极包括正极集流体、保护层和正极活性材料层。所述保护层设置于所述正极集流体与所述正极活性材料层之间。所述保护层包含无机颗粒，采用激光粒度仪进行测试，所述无机颗粒满足Dv5≤0.5μm，其中，Dv5表示所述无机颗粒的累积体积分布数达到5％时所对应的粒径。通过控制保护层中的无机颗粒满足Dv5≤0.5um，能够使无机颗粒更均匀、全面的覆盖正极集流体，特别是在卷绕结构的拐角处，能够具有充足的小粒径无机颗粒进行填充，从而更好地覆盖拐角处的正极集流体；且在电化学装置受到侧边挤压时，保护层随着极片的弯曲而存在内应力，特别是在卷绕结构的拐角处，由于拐角处自身存在弯曲应力，在受到侧边挤压时，应力将更加集中，保护层中的小粒径无机颗粒可以促进无机颗粒之间的滑移，降低内应力，抑制保护层脱落，从而降低正极集流体与负极活性材料层之间的短路风险，进而提高电化学装置的安全性能。According to one aspect of the present application, the present application provides an electrochemical device, which includes: a positive electrode, the positive electrode includes a positive electrode current collector, a protective layer and a positive electrode active material layer. The protective layer is disposed between the cathode current collector and the cathode active material layer. The protective layer contains inorganic particles, which are tested using a laser particle size analyzer. The inorganic particles satisfy Dv5 ≤ 0.5 μm, where Dv5 represents the particle size corresponding to when the cumulative volume distribution number of the inorganic particles reaches 5%. By controlling the inorganic particles in the protective layer to meet Dv5 ≤ 0.5um, the inorganic particles can more uniformly and comprehensively cover the cathode current collector. Especially at the corners of the winding structure, there can be sufficient small-sized inorganic particles for filling. Thereby better covering the positive electrode current collector at the corners; and when the electrochemical device is squeezed from the side, the protective layer will have internal stress as the pole piece bends, especially at the corners of the rolled structure, because the corners It has bending stress. When it is squeezed from the side, the stress will be more concentrated. The small-sized inorganic particles in the protective layer can promote the slip between inorganic particles, reduce the internal stress, inhibit the shedding of the protective layer, thereby reducing the concentration of the positive electrode. The risk of short circuit between the fluid and the negative active material layer, thereby improving the safety performance of the electrochemical device.

在一些实施例中，所述保护层的厚度为H1μm，满足Dv50/H1≤0.4，其中， Dv50表示采用激光粒度仪进行测试，所述无机颗粒的累积体积分布数达到50％时所对应的粒径，单位为μm。此时，在电化学装置受到外力撞击或挤压时，能够具有充足的无机颗粒在保护层的厚度方向上相互滑移，从而进一步降低保护层内部的应力，抑制保护层的脱落，从而降低正极集流体和负极活性材料层之间短路的风险，进一步提高电化学装置的安全性能。In some embodiments, the thickness of the protective layer is H1 μm, which satisfies Dv50/H1≤0.4, where Dv50 represents the particle size corresponding to when the cumulative volume distribution number of the inorganic particles reaches 50% when tested using a laser particle size analyzer. diameter in μm. At this time, when the electrochemical device is impacted or squeezed by an external force, sufficient inorganic particles can slide each other in the thickness direction of the protective layer, thereby further reducing the stress inside the protective layer, inhibiting the shedding of the protective layer, and thus reducing the positive electrode The risk of short circuit between the current collector and the negative active material layer further improves the safety performance of the electrochemical device.

在一些实施例中，满足Dv90/H1＜1，其中，Dv90表示所述无机颗粒的累积体积分布数达到90％时所对应的粒径，单位为μm。此时，无机颗粒中粒径过大的粒子数较少，在电化学装置受到外力撞击或挤压时，能够进一步降低保护层内部的应力，抑制保护层的脱落，从而降低正极集流体和负极活性材料层之间短路的风险，进一步提高电化学装置的安全性能。In some embodiments, Dv90/H1<1 is satisfied, where Dv90 represents the particle diameter corresponding to when the cumulative volume distribution number of the inorganic particles reaches 90%, in μm. At this time, the number of particles with excessively large diameters in the inorganic particles is small. When the electrochemical device is impacted or squeezed by external forces, the stress inside the protective layer can be further reduced, inhibiting the shedding of the protective layer, thereby reducing the positive electrode current collector and the negative electrode. The risk of short circuits between active material layers further improves the safety performance of electrochemical devices.

在一些实施例中，满足0.5≤H1≤10。In some embodiments, 0.5≤H1≤10 is satisfied.

在一些实施例中，所述无机颗粒包含第一颗粒和第二颗粒。In some embodiments, the inorganic particles include first particles and second particles.

在一些实施例中，所述第一颗粒包含A元素，所述A元素包含Al、Mg、Si、Ca、Ti、Ce、Zn、Y、Hf、Zr、Ba或Sn中的至少一种。In some embodiments, the first particles include an A element including at least one of Al, Mg, Si, Ca, Ti, Ce, Zn, Y, Hf, Zr, Ba, or Sn.

在一些实施例中，所述第二颗粒包含Li元素和M元素，所述M元素包含Mn或Fe中的至少一种。In some embodiments, the second particles include Li element and M element, and the M element includes at least one of Mn or Fe.

在一些实施例中，所述第一颗粒包含氧化铝、氧化镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化锌、氧化钙、氧化锆、氧化钇、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙、硅酸钙、硬水铝石、硫酸钡、硫酸钙或硅酸钙中的至少一种。In some embodiments, the first particles comprise aluminum oxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, ceria, zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, boehmite, hydroxide At least one of aluminum, magnesium hydroxide, calcium hydroxide, calcium silicate, diaspore, barium sulfate, calcium sulfate or calcium silicate.

在一些实施例中，所述第二颗粒包含磷酸铁锂、磷酸锰铁锂或锰酸锂中的至少一种。In some embodiments, the second particles comprise at least one of lithium iron phosphate, lithium iron manganese phosphate, or lithium manganate.

在一些实施例中，所述保护层包含粘结剂。在一些实施例中，所述粘结剂为水性粘结剂。水性粘结剂可提高保护层与正极集流体和正极活性材料层之间的粘结力，改善电化学装置高温存储的内阻增长率。In some embodiments, the protective layer includes an adhesive. In some embodiments, the binder is an aqueous binder. The water-based binder can improve the bonding force between the protective layer and the cathode current collector and cathode active material layer, and improve the internal resistance growth rate of the electrochemical device during high-temperature storage.

在一些实施例中，所述粘结剂包含丙烯酸、丙烯酸盐、丙烯腈、丙烯酰胺或丙烯酸酯中的至少一种形成的聚合物。In some embodiments, the binder includes a polymer formed from at least one of acrylic acid, an acrylate, acrylonitrile, acrylamide, or an acrylate.

在一些实施例中，所述粘结剂包含包含羧甲基纤维素盐或丁腈橡胶中的至少一种。In some embodiments, the binder includes at least one of carboxymethyl cellulose salts or nitrile rubber.

在一些实施例中，所述粘结剂的重量平均分子量为18万至220万。In some embodiments, the binder has a weight average molecular weight of 180,000 to 2.2 million.

在一些实施例中，所述保护层还包含导电剂。在一些实施例中，所述导电剂包含片层状、网状、线状或颗粒状导电剂中的至少一种。在一些实施例中，基于所述保护层的质量，所述导电剂的质量百分比为0.3％至20％。In some embodiments, the protective layer further includes a conductive agent. In some embodiments, the conductive agent includes at least one of sheet-like, mesh-like, linear or granular conductive agents. In some embodiments, the mass percentage of the conductive agent is 0.3% to 20% based on the mass of the protective layer.

在一些实施例中，0.1≤Dv50≤1.5。在一些实施例中，0.4≤Dv90≤3.5。In some embodiments, 0.1≤Dv50≤1.5. In some embodiments, 0.4≤Dv90≤3.5.

在一些实施例中，所述保护层还包含流平剂。在一些实施例中，基于所述保护层的质量，所述流平剂的质量百分比为大于0％且小于或者等于6％。In some embodiments, the protective layer further includes a leveling agent. In some embodiments, based on the mass of the protective layer, the mass percentage of the leveling agent is greater than 0% and less than or equal to 6%.

在一些实施例中，所述流平剂包含包括硅氧烷类化合物、硅氧烷类衍生物、含氧烯烃聚合物、丙烯酸酯类聚合物、丙烯酸盐类聚合物、醇类化合物、醚类化合物或氟碳化合物中的至少一种。In some embodiments, the leveling agent includes silicone compounds, silicone derivatives, oxygen-containing olefin polymers, acrylate polymers, acrylate polymers, alcohol compounds, ethers At least one of compounds or fluorocarbons.

在一些实施例中，所述电化学装置在满充状态下，所述正极的电阻为RΩ，满足1≤R≤10。In some embodiments, when the electrochemical device is in a fully charged state, the resistance of the positive electrode is RΩ, satisfying 1≤R≤10.

根据本申请的另一方面，本申请提供包含根据前述任一实施例所述的电化学装置的电子装置。According to another aspect of the present application, the present application provides an electronic device including the electrochemical device according to any of the preceding embodiments.

具体实施方式Detailed ways

下文中，对本申请进行详细说明。应当理解，在说明书和所附权利要求中使用的术语不应被解释为限于一般和词典的含义，而是在发明人被允许适当定义术语以进行最佳解释的原则的基础上基于与本申请的技术方面相对应的含义和概念来解释。因此，说明书中所述的实施方案中所示的描述仅仅是用于说明的目的的具体实例，而不旨在显示本申请的所有技术方面，并且应当理解，在提交本申请时可以对其完成多种可选等价体和变体。Hereinafter, the present application is described in detail. It is to be understood that the terms used in the specification and appended claims should not be construed to be limited to their ordinary and dictionary meanings, but rather on the basis that the inventor is allowed to appropriately define the terms for the best interpretation based on the principles associated with this application. The corresponding meanings and concepts of the technical aspects are explained. Accordingly, the descriptions shown in the embodiments described in the specification are specific examples for illustrative purposes only and are not intended to demonstrate all technical aspects of the application, and it will be understood that they may be completed by the time this application is filed. Many optional equivalents and variants.

在具体实施方式及权利要求书中，由术语“中的至少一者”、“中的至少一个”、“中的至少一种”或其他相似术语所连接的项目的列表可意味着所列项目的任何组合。例如，如果列出项目A及B，那么短语“A及B中的至少一者”意味着仅A；仅B；或A及B。在另一实例中，如果列出项目A、B及C，那么短语“A、B及C中的至少一者”意味着仅A；或仅B；仅C；A及B(排除C)；A及C(排除B)；B及C(排除A)；或A、B及C的全部。项目A可包含单个组件或多个组件。项目B可包含单个组件或多个组件。项目C可包含单个组件或多个组件。In the detailed description and claims, a list of items connected by the term "at least one of," "at least one of," "at least one of," or other similar terms may mean that the listed items any combination of. For example, if items A and B are listed, the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if the items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B and C. Project A can contain a single component or multiple components. Project B can contain a single component or multiple components. Project C may contain a single component or multiple components.

另外，有时在本文中以范围格式呈现量、比率和其它数值。应理解，此类范围格式是用于便利及简洁起见，且应灵活地理解，不仅包含明确地指定为范围限制的数值，而且包含涵盖于所述范围内的所有个别数值或子范围，如同明确地指定每一数值及子范围一般。Additionally, quantities, ratios, and other numerical values are sometimes presented herein in range format. It should be understood that such range formats are for convenience and brevity, and should be flexibly construed to include not only the values expressly designated as range limits, but also all individual values or subranges encompassed within the stated range, as if expressly Specify each value and subrange individually.

一、电化学装置1. Electrochemical device

本申请提供一种电化学装置，其包括：正极，所述正极包括正极集流体、保护层和正极活性材料层。所述保护层设置于所述正极集流体与所述正极活性材料层之间。所述保护层包含无机颗粒，采用激光粒度仪进行测试，所述无机颗粒满足Dv5≤0.5μm，其中，Dv5表示所述无机颗粒的累积体积分布数达到5％时所对应的粒径。The present application provides an electrochemical device, which includes: a positive electrode including a positive current collector, a protective layer and a positive active material layer. The protective layer is disposed between the cathode current collector and the cathode active material layer. The protective layer contains inorganic particles, which are tested using a laser particle size analyzer. The inorganic particles satisfy Dv5 ≤ 0.5 μm, where Dv5 represents the particle size corresponding to when the cumulative volume distribution number of the inorganic particles reaches 5%.

一方面，通过在正极集流体与正极活性材料层之间设置保护层，可以降低电化学装置在受到外力撞击或挤压时，发生正极集流体与负极活性材料层之间短路的风险，从而提高电化学装置的安全性能。另一方面，通过控制保护层中的无机颗粒满足Dv5≤0.5um，能够使无机颗粒更均匀、全面的覆盖正极集流体，特别是在卷绕结构的拐角处，能够具有充足的小粒径无机颗粒进行填充，从而更好地覆盖拐角处的正极集流体；且在电化学装置受到侧边挤压时，保护层随着极片的弯曲而存在内应力，特别是在卷绕结构的拐角处，由于拐角处自身存在弯曲应力，在受到侧边挤压时，应力将更加集中，保护层中的小粒径无机颗粒可以促进无机颗粒之间的滑移，降低内应力，抑制保护层脱落，从而降低正极集流体与负极活性材料层之间的短路风险，进一步提高电化学装置的安全性能。On the one hand, by providing a protective layer between the positive current collector and the positive active material layer, the risk of a short circuit between the positive current collector and the negative active material layer can be reduced when the electrochemical device is impacted or squeezed by external forces, thereby improving Safety performance of electrochemical devices. On the other hand, by controlling the inorganic particles in the protective layer to meet Dv5 ≤ 0.5um, the inorganic particles can more uniformly and comprehensively cover the cathode current collector, especially at the corners of the winding structure, which can have sufficient small particle size inorganic The particles are filled to better cover the positive electrode current collector at the corners; and when the electrochemical device is squeezed from the side, the protective layer has internal stress as the electrode piece bends, especially at the corners of the rolled structure , due to the bending stress at the corner itself, the stress will be more concentrated when squeezed by the side. The small-sized inorganic particles in the protective layer can promote the slip between inorganic particles, reduce the internal stress, and inhibit the shedding of the protective layer. This reduces the risk of short circuit between the positive electrode current collector and the negative electrode active material layer, and further improves the safety performance of the electrochemical device.

在一些实施例中，Dv5为0.05μm、0.08μm、0.1μm、0.15μm、0.2μm、0.25μm、0.3μm、0.35μm、0.4μm、0.45μm、0.5μm或前述任意两数值之间的范围。In some embodiments, Dv5 is 0.05 μm, 0.08 μm, 0.1 μm, 0.15 μm, 0.2 μm, 0.25 μm, 0.3 μm, 0.35 μm, 0.4 μm, 0.45 μm, 0.5 μm, or a range between any two of the aforementioned values.

在一些实施例中，保护层的厚度为H1μm，满足Dv50/H1≤0.4，其中，Dv50表示采用激光粒度仪进行测试，所述无机颗粒的累积体积分布数达到50％时所对应的粒径，单位为μm。此时，在电化学装置受到外力撞击或挤压时，能够具有充足的无机颗粒在保护层的厚度方向上相互滑移，从而进一步降低保护层内部的应力，抑制保护层的脱落，从而降低正极集流体和负极活性材料层之间短路的风险，进一步提高电化学装置的安全性能。在一些实施例中，Dv50/H1的值为0.01、0.05、0.1、0.15、0.2、0.25、0.3、0.35、0.4或前述任意两数值之间的范围。In some embodiments, the thickness of the protective layer is H1 μm, which satisfies Dv50/H1≤0.4, where Dv50 represents the particle size corresponding to when the cumulative volume distribution number of the inorganic particles reaches 50% when tested using a laser particle size analyzer, The unit is μm. At this time, when the electrochemical device is impacted or squeezed by an external force, sufficient inorganic particles can slide each other in the thickness direction of the protective layer, thereby further reducing the stress inside the protective layer, inhibiting the shedding of the protective layer, and thus reducing the positive electrode The risk of short circuit between the current collector and the negative active material layer further improves the safety performance of the electrochemical device. In some embodiments, the value of Dv50/H1 is 0.01, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, or a range between any two of the aforementioned values.

在一些实施例中，保护层满足Dv90/H1＜1，其中，Dv90表示采用激光粒度仪进行测试，所述无机颗粒的累积体积分布数达到90％时所对应的粒径。此时，无机颗粒中粒径过大的粒子数较少，在电化学装置受到外力撞击或挤压时，能够进一步降低保护层内部的应力，抑制保护层的脱落，从而降低正极集流体和负极活性材料层之间短路的风险，进一步提高电化学装置的安全性能。在一些实施例中，Dv90/H1的值为0.01、0.05、0.1、0.15、0.2、0.25、0.3、0.35、0.4、0.45、0.5、0.6、0.65、0.7、0.75、0.8、0.85、0.9、0.95或前述任意两数值之间的范围。In some embodiments, the protective layer satisfies Dv90/H1<1, where Dv90 represents the particle size corresponding to when the cumulative volume distribution number of the inorganic particles reaches 90% when tested using a laser particle size analyzer. At this time, the number of particles with excessively large diameters in the inorganic particles is small. When the electrochemical device is impacted or squeezed by external forces, the stress inside the protective layer can be further reduced, inhibiting the shedding of the protective layer, thereby reducing the positive electrode current collector and the negative electrode. The risk of short circuits between active material layers further improves the safety performance of electrochemical devices. In some embodiments, the value of Dv90/H1 is 0.01, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, or The range between any two values mentioned above.

在一些实施例中，0.1≤Dv50≤1.5。在一些实施例中，Dv50为0.1、0.15、0.2、0.25、0.3、0.35、0.4、0.45、0.5、0.55、0.6、0.65、0.7、0.75、0.8、0.85、0.9、1、1.05、1.15、1.2、1.4、1.5或前述任意两数值之间的范围。In some embodiments, 0.1≤Dv50≤1.5. In some embodiments, Dv50 is 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 1, 1.05, 1.15, 1.2, 1.4, 1.5 or the range between any two values mentioned above.

在一些实施例中，0.4≤Dv90≤3.5。在一些实施例中，Dv90为0.4、0.45、0.5、0.55、0.6、0.65、0.7、0.75、0.8、0.85、0.9、1、1.5、2、2.5、3、3.5或前述任意两数值之间的范围。In some embodiments, 0.4≤Dv90≤3.5. In some embodiments, Dv90 is 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, or a range between any two of the aforementioned values .

在一些实施例中，H1为0.5μm至10μm。在一些实施例中，H1为0.5μm、0.8μm、1.2μm、1.6μm、2μm、2.4μm、2.8μm、3.2μm、3.6μm、4μm、4.4μm、4.8μm、5.2μm、5.6μm、6μm、6.4μm、6.8μm、7.2μm、7.6μm、8μm、8.4μm、9μm、9.4μm、9.8μm、10μm或前述任意两数值之间的范围。In some embodiments, H1 is 0.5 μm to 10 μm. In some embodiments, H1 is 0.5 μm, 0.8 μm, 1.2 μm, 1.6 μm, 2 μm, 2.4 μm, 2.8 μm, 3.2 μm, 3.6 μm, 4 μm, 4.4 μm, 4.8 μm, 5.2 μm, 5.6 μm, 6 μm, 6.4μm, 6.8μm, 7.2μm, 7.6μm, 8μm, 8.4μm, 9μm, 9.4μm, 9.8μm, 10μm or the range between any two of the aforementioned values.

在一些实施例中，无机颗粒包含第一颗粒和/或第二颗粒。在一些实施例中，无机颗粒包含第一颗粒和第二颗粒。In some embodiments, the inorganic particles include first particles and/or second particles. In some embodiments, the inorganic particles include first particles and second particles.

在一些实施例中，第一颗粒包含A元素，A元素可包含Al、Mg、Si、Ca、Ti、Ce、Zn、Y、Hf、Zr、Ba或Sn中的至少一种。在一些实施例中，第一颗粒包含氧化铝、氧化镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化锌、氧化钙、氧化锆、氧化钇、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙、硅酸钙、硬水铝石、硫酸钡、硫酸钙或硅酸钙中的至少一种。在一些实施例中，Al源自于勃姆石、氧化铝、氢氧化铝、硬水铝石中的至少一种。在一些实施例中，Si源自于高岭土或硅酸钙中的至少一种。在一些实施例中，Ba源自于硫酸钡。在一些实施例中，Ca源自于氧化钙、硫酸钙或硅酸钙中的至少一种。在一些实施例中，Mg源自于氧化镁或氢氧化镁中的至少一种。In some embodiments, the first particles include A element, and the A element may include at least one of Al, Mg, Si, Ca, Ti, Ce, Zn, Y, Hf, Zr, Ba, or Sn. In some embodiments, the first particles comprise aluminum oxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, ceria, zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, boehmite, aluminum hydroxide, At least one of magnesium hydroxide, calcium hydroxide, calcium silicate, diaspore, barium sulfate, calcium sulfate or calcium silicate. In some embodiments, Al is derived from at least one of boehmite, aluminum oxide, aluminum hydroxide, and diaspore. In some embodiments, Si is derived from at least one of kaolin or calcium silicate. In some embodiments, Ba is derived from barium sulfate. In some embodiments, Ca is derived from at least one of calcium oxide, calcium sulfate, or calcium silicate. In some embodiments, Mg is derived from at least one of magnesium oxide or magnesium hydroxide.

在一些实施例中，基于所述保护层的质量，第一颗粒的质量百分比为0％至93.5％。在一些实施例中，第一颗粒的质量百分比为0％、5％、10％、15％、20％、25％、30％、35％、40％、45％、50％、55％、60％、65％、70％、75％、80％、85％、90％、93.5％或前述任意两数值之间的范围。In some embodiments, based on the mass of the protective layer, the mass percentage of the first particles is 0% to 93.5%. In some embodiments, the mass percentage of the first particles is 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60 %, 65%, 70%, 75%, 80%, 85%, 90%, 93.5% or the range between any two of the aforementioned values.

在一些实施例中，第二颗粒包含Li元素和M元素，M元素包含Mn或Fe中的至少一种。在一些实施例中，第二颗粒包含磷酸铁锂(简写为LFP)、磷酸锰铁锂(简写为LFMP)或锰酸锂(简写为LMO)中的至少一种。在一些实施例中，Li源自于磷酸铁锂(简写为LFP)、磷酸锰铁锂(简写为LFMP)或锰酸锂(简写为LMO)中的至少一种。在一些实施例中，Mn源自于磷酸锰铁锂(LFMP)或锰酸锂(LMO)中的至少一种。在一些实施例中，Fe源自于磷酸铁锂(LFP)或磷酸锰铁锂(LFMP)中的至少一种。In some embodiments, the second particles include Li element and M element, and the M element includes at least one of Mn or Fe. In some embodiments, the second particles include at least one of lithium iron phosphate (abbreviated as LFP), lithium iron manganese phosphate (abbreviated as LFMP), or lithium manganate (abbreviated as LMO). In some embodiments, Li is derived from at least one of lithium iron phosphate (abbreviated as LFP), lithium iron manganese phosphate (abbreviated as LFMP) or lithium manganate (abbreviated as LMO). In some embodiments, Mn is derived from at least one of lithium iron manganese phosphate (LFMP) or lithium manganate (LMO). In some embodiments, Fe is derived from at least one of lithium iron phosphate (LFP) or lithium iron manganese phosphate (LFMP).

在一些实施例中，基于保护层的质量，第二颗粒的质量百分比0％至98.5％。在一些实施例中，第二颗粒的质量百分比为0％、5％、10％、15％、20％、25％、30％、35％、40％、45％、50％、55％、60％、65％、70％、75％、80％、85％、90％、95％、98.5％或前述任意两数值之间的范围。In some embodiments, the mass percentage of the second particles is 0% to 98.5% based on the mass of the protective layer. In some embodiments, the mass percentage of the second particles is 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60 %, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98.5% or the range between any two of the aforementioned values.

在一些实施例中，保护层包含第一粘结剂。在一些实施例中，第一粘结剂为水性粘结剂。水性粘结剂可提高保护层与正极集流体和正极活性材料层之间的粘结力，改善电化学装置高温存储的内阻增长率。In some embodiments, the protective layer includes a first adhesive. In some embodiments, the first binder is an aqueous binder. The water-based binder can improve the bonding force between the protective layer and the cathode current collector and cathode active material layer, and improve the internal resistance growth rate of the electrochemical device during high-temperature storage.

在一些实施例中，第一粘结剂包含丙烯酸、丙烯酸盐、丙烯腈、丙烯酰胺或丙烯酸酯中的至少一种形成的聚合物。In some embodiments, the first binder includes a polymer formed from at least one of acrylic acid, an acrylate, acrylonitrile, acrylamide, or an acrylate.

在一些实施例中，第一粘结剂包含羧甲基纤维素盐或丁腈橡胶中的至少一者。In some embodiments, the first binder includes at least one of carboxymethylcellulose salt or nitrile rubber.

在一些实施例中，第一粘结剂包含丙烯酸盐，以及丙烯酸、丙烯腈、丙烯酸酯中的至少一种形成的聚合物。In some embodiments, the first binder includes an acrylate and a polymer formed from at least one of acrylic acid, acrylonitrile, and acrylate.

在一些实施例中，第一粘结剂的重量平均分子量为18万至220万。在一些实施例中，第一粘结剂的重量平均分子量为20万至180万。在一些实施例中，第一粘结剂的重量平均分子量为20万至160万。在一些实施例中，第一粘结剂的重量平均分子量为18万、20万、25万、30万、35万、40万、45万、50万、55万、60万、65万、70万、75万、80万、90万、95万、100万、110万、120万、120万、130万、140万、150万、160万、170万、180万、190万、200万、220万或前述任意两数值之间的范围。In some embodiments, the first binder has a weight average molecular weight of 180,000 to 2.2 million. In some embodiments, the first binder has a weight average molecular weight of 200,000 to 1.8 million. In some embodiments, the first binder has a weight average molecular weight of 200,000 to 1.6 million. In some embodiments, the weight average molecular weight of the first binder is 180,000, 200,000, 250,000, 300,000, 350,000, 400,000, 450,000, 500,000, 550,000, 600,000, 650,000, 70 Ten thousand, 750,000, 800,000, 900,000, 950,000, 1 million, 1.1 million, 1.2 million, 1.2 million, 1.3 million, 1.4 million, 1.5 million, 1.6 million, 1.7 million, 1.8 million, 1.9 million, 2 million, 2.2 million or the range between any two values mentioned above.

在一些实施例中，基于保护层的质量，第一粘结剂的质量百分比为0.5％至21％。在一些实施例中，第一粘结剂的质量百分比为0.5％、1％、2％、3％、4％、4.5％、5％、5.5％、6％、6.5％、7％、7.5％、8％、8.5％、9％、10％、11％、12％、13％、14％、15％、16％、17％、18％、19％、20％、21％或前述任意两数值之间的范围。In some embodiments, the mass percentage of the first binder is 0.5% to 21% based on the mass of the protective layer. In some embodiments, the mass percentage of the first binder is 0.5%, 1%, 2%, 3%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5% , 8%, 8.5%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21% or any two of the above values range between.

在一些实施例中，保护层包含第一导电剂。在一些实施例中，所述第一导电剂可包含片层状、网状、线状或颗粒状导电剂中的至少一种。在一些实施例中，所述第一导电剂包含石墨烯(简写为GN)、石墨纤维、碳纳米管(简写为CNT)、科琴黑或导电碳(简写为SP)中的至少一种。In some embodiments, the protective layer includes a first conductive agent. In some embodiments, the first conductive agent may include at least one of sheet-like, mesh-like, linear or granular conductive agents. In some embodiments, the first conductive agent includes at least one of graphene (GN for short), graphite fiber, carbon nanotube (CNT for short), Ketjen black or conductive carbon (SP for short).

在一些实施例中，基于保护层的质量，第一导电剂的质量百分比为0.3％至20％。在一些实施例中，第一导电剂的质量百分比为0.3％、0.4％、0.5％、0.6％、0.7％、0.8％、0.9％、1％、1.2％、1.4％、1.5％、1.6％、1.7％、1.8％、1.9％、2％、2.1％、2.2％、 2.3％、2.4％、2.5％、2.6％、2.7％、2.8％、2.9％、3％、3.2％、3.4％、3.6％、3.8％、4％、4.2％、4.4％、4.6％、4.8％、5％、5.5％、6％、6.5％、7％、7.5％、8％、10％、12％、14％、16％、18％、20％或前述任意两数值之间的范围。In some embodiments, based on the mass of the protective layer, the mass percentage of the first conductive agent is 0.3% to 20%. In some embodiments, the mass percentage of the first conductive agent is 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.2%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, 3.2%, 3.4%, 3.6% , 3.8%, 4%, 4.2%, 4.4%, 4.6%, 4.8%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 10%, 12%, 14%, 16 %, 18%, 20% or the range between any two of the aforementioned values.

在一些实施例中，保护层还包含流平剂。在一些实施例中，所述流平剂可包含硅氧烷类化合物、硅氧烷类衍生物、含氧烯烃聚合物、丙烯酸酯类聚合物、丙烯酸盐类聚合物、醇类化合物、醚类化合物或氟碳化合物中的至少一种。在一些实施例中，流平剂包含聚二甲基硅氧烷、乙氧基丙烯-丙氧基丙烯聚合物或氟碳改性聚丙烯酸酯中的至少一种。In some embodiments, the protective layer further includes a leveling agent. In some embodiments, the leveling agent may include silicone compounds, silicone derivatives, oxygen-containing olefin polymers, acrylate polymers, acrylate polymers, alcohol compounds, ethers At least one of compounds or fluorocarbons. In some embodiments, the leveling agent includes at least one of polydimethylsiloxane, ethoxypropylene-propoxypropylene polymer, or fluorocarbon modified polyacrylate.

在一些实施例中，基于保护层的质量，流平剂的质量百分比为大于0％且小于或者等于6％。在一些实施例中，流平剂的质量百分比为0.001％、0.01％、0.02％、0.03％、0.04％、0.05％、0.06％、0.07％、0.08％、0.09％、0.1％、0.15％、0.2％、0.3％、0.4％、0.5％、0.6％、0.7％、0.8％、0.9％、1％、1.5％、2％、2.5％、3％、3.5％、4％、4.5％、5％、5.5％、6％或前述任意两数值之间的范围。流平剂有利于形成均匀、平滑的保护层，增加保护层和集流体以及正极活性材料层的接触面积，从而抑制电化学装置高温存储的内阻增长。In some embodiments, based on the mass of the protective layer, the mass percentage of the leveling agent is greater than 0% and less than or equal to 6%. In some embodiments, the mass percentage of the leveling agent is 0.001%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2 %, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6% or the range between any two of the aforementioned values. The leveling agent is beneficial to forming a uniform and smooth protective layer, increasing the contact area between the protective layer and the current collector and the positive active material layer, thereby inhibiting the growth of the internal resistance of the electrochemical device during high-temperature storage.

在一些实施例中，所述正极活性材料层包含活性物质、第二粘结剂和第二导电剂。In some embodiments, the positive active material layer includes an active material, a second binder, and a second conductive agent.

在一些实施例中，活性物质包含钴酸锂(简写为LCO)。在一些实施例中，基于正极活性材料层的质量，活性物质的质量百分比为94％至99％。在一些实施例中，基于正极活性材料层的质量，活性物质的质量百分比为94％、94.5％、95％、95.5％、96％、96.5％、97％、97.5％、98％、98.5％、99％或前述任意两数值之间的范围。In some embodiments, the active material includes lithium cobalt oxide (abbreviated as LCO). In some embodiments, the mass percentage of the active material is 94% to 99% based on the mass of the cathode active material layer. In some embodiments, based on the mass of the cathode active material layer, the mass percentage of the active material is 94%, 94.5%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99% or the range between any two values mentioned above.

在一些实施例中，第二粘结剂包含聚偏氟乙烯(简写为PVDF)、丁腈橡胶或聚丙烯酸酯中的至少一种。在一些实施例中，基于正极活性材料层的质量，第二粘结剂的质量百分比为0.5％至2.5％。在一些实施例中，基于正极活性材料层的质量，第二粘结剂的质量百分比为0.5％、1％、1.5％、2％、2.5％或前述任意两数值之间的范围。In some embodiments, the second adhesive includes at least one of polyvinylidene fluoride (abbreviated as PVDF), nitrile rubber, or polyacrylate. In some embodiments, the mass percentage of the second binder is 0.5% to 2.5% based on the mass of the cathode active material layer. In some embodiments, based on the mass of the cathode active material layer, the mass percentage of the second binder is 0.5%, 1%, 1.5%, 2%, 2.5% or a range between any two of the aforementioned values.

在一些实施例中，第二导电剂包含石墨烯、石墨纤维、碳纳米管、科琴黑或导电碳中的至少一种。在一些实施例中，基于正极活性材料层的总质量，第二导电剂的质量百分比为0.5％至3.5％。在一些实施例中，基于正极活性材料层的质量，第二导电剂的质量百分比为0.5％、1％、1.5％、2％、2.5％、3％、3.5％或前述任意两数值之间的范围。In some embodiments, the second conductive agent includes at least one of graphene, graphite fibers, carbon nanotubes, Ketjen black, or conductive carbon. In some embodiments, the mass percentage of the second conductive agent is 0.5% to 3.5% based on the total mass of the cathode active material layer. In some embodiments, based on the mass of the cathode active material layer, the mass percentage of the second conductive agent is 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5% or between any two of the aforementioned values. scope.

本申请通过在电化学装置的正极集流体与正极活性材料层之间设置保护层，可以降低电化学装置在受到外力撞击或挤压时，发生正极集流体与负极活性材料层之间短路的风险，从而提高电化学装置的安全性能。同时，本申请认识到，藉由控制保护层的材料使其包含无机颗粒，并控制其采用激光粒度仪进行测试，所述无机颗粒满足Dv5≤0.5μm时(其中，Dv5表示所述无机颗粒的累积体积分布数达到5％时所对应的粒径)，能够使无机颗粒更均匀、全面的覆盖正极集流体，特别是在卷绕结构的拐角处，能够具有充足的小粒径无机颗粒进行填充，从而更好地覆盖拐角处的正极集流体；且在电化学装置受到侧边挤压时，保护层随着极片的弯曲而存在内应力，特别是在卷绕结构的拐角处，由于拐角处自身存在弯曲应力，在受到侧边挤压时，应力将更加集中，保护层中的小粒径无机颗粒可以促进无机颗粒之间的滑移，降低内应力，抑制保护层脱落，从而降低正极集流体与负极活性材料层之间的短路风险，进一步提高电化学装置的安全性能。By arranging a protective layer between the positive electrode current collector and the positive electrode active material layer of the electrochemical device, the present application can reduce the risk of short circuit between the positive electrode current collector and the negative electrode active material layer when the electrochemical device is impacted or squeezed by external force. , thereby improving the safety performance of electrochemical devices. At the same time, the present application recognizes that by controlling the material of the protective layer to include inorganic particles, and controlling it to be tested using a laser particle size analyzer, the inorganic particles satisfy Dv5≤0.5 μm (wherein, Dv5 represents the size of the inorganic particles) The corresponding particle size when the cumulative volume distribution number reaches 5%), which can make the inorganic particles more uniformly and comprehensively cover the cathode current collector, especially at the corners of the winding structure, there can be sufficient small-sized inorganic particles for filling , thereby better covering the positive electrode current collector at the corners; and when the electrochemical device is squeezed from the side, the protective layer will have internal stress as the pole piece bends, especially at the corners of the rolled structure, due to the corner There is bending stress at the surface itself. When squeezed from the side, the stress will be more concentrated. The small-sized inorganic particles in the protective layer can promote the slip between the inorganic particles, reduce the internal stress, inhibit the shedding of the protective layer, and thereby reduce the cost of the positive electrode. The risk of short circuit between the current collector and the negative active material layer further improves the safety performance of the electrochemical device.

本申请的电化学装置还包括隔离膜、电解液和负极。The electrochemical device of the present application also includes a separator, an electrolyte and a negative electrode.

在一些实施例中，本申请的电化学装置包括，但不限于：所有种类的一次电池或二次电池。在一些实施例中，所述电化学装置是锂二次电池。在一些实施例中，锂二次电池包括，但不限于：锂金属二次电池、锂离子二次电池、锂聚合物二次电池或锂离子聚合物二次电池。In some embodiments, electrochemical devices of the present application include, but are not limited to: all kinds of primary or secondary batteries. In some embodiments, the electrochemical device is a lithium secondary battery. In some embodiments, lithium secondary batteries include, but are not limited to: lithium metal secondary batteries, lithium ion secondary batteries, lithium polymer secondary batteries, or lithium ion polymer secondary batteries.

二、一种制备前述电化学装置的方法2. A method of preparing the aforementioned electrochemical device

如下以锂离子电池为例详细描述了本申请的电化学装置的制备方法。The preparation method of the electrochemical device of the present application is described in detail below by taking a lithium-ion battery as an example.

负极的制备：将负极活性物质(碳材料、硅材料或钛酸锂中的至少一种)和负极粘结剂，以及可选的导电材料，按一定的质量比分散于溶剂体系中充分搅拌混合均匀后，涂覆于负极集流体上，经过烘干、冷压，得到负极。Preparation of the negative electrode: Disperse the negative electrode active material (at least one of carbon material, silicon material or lithium titanate) and negative electrode binder, as well as optional conductive material, into the solvent system according to a certain mass ratio and stir thoroughly. After uniformity, it is coated on the negative electrode current collector, dried and cold pressed to obtain the negative electrode.

正极的制备：Preparation of positive electrode:

(1)将无机颗粒、第一导电剂、第一粘结剂，以及可选的流平剂，加入溶剂中混合均匀，获得保护层的浆料(在后称作“第一浆料”)；(1) Add inorganic particles, first conductive agent, first binder, and optional leveling agent to the solvent and mix evenly to obtain a slurry for the protective layer (hereinafter referred to as "first slurry") ;

(2)将步骤(1)中的第一浆料涂覆在正极集流体的目标区域；(2) Apply the first slurry in step (1) to the target area of the positive electrode current collector;

(3)将步骤(2)中的获得的含有第一浆料的正极集流体进行烘干以去除溶剂，得到涂有保护层的正极集流体；(3) Drying the positive electrode current collector containing the first slurry obtained in step (2) to remove the solvent to obtain a positive electrode current collector coated with a protective layer;

(4)将活性物质、第二导电剂、第二粘结剂按一定的质量比分散于溶剂体系中充分搅拌混合均匀，得到正极活性物质的浆料(在后称作“第二浆料”)；(4) Disperse the active material, the second conductive agent, and the second binder in a solvent system at a certain mass ratio and stir thoroughly to mix evenly to obtain a slurry of the positive electrode active material (hereinafter referred to as "second slurry" );

(5)将第二浆料涂覆在步骤(3)中得到的涂有保护层的正极集流体的目标区域；(5) Coating the second slurry on the target area of the positive electrode current collector coated with the protective layer obtained in step (3);

(6)将步骤(5)中的含有第二浆料的正极集流体进行烘干以去除溶剂，从而得到所要正极。(6) Dry the positive electrode current collector containing the second slurry in step (5) to remove the solvent, thereby obtaining the desired positive electrode.

无机颗粒、第一导电剂、第一粘结剂、活性物质、第二导电剂和第二粘结剂的种类如前述。The types of inorganic particles, first conductive agent, first binder, active material, second conductive agent and second binder are as described above.

在一些实施例中，所述溶剂的示例包括但不限于N-甲基吡咯烷酮、丙酮或水。在一些实施例中，可适当的调节溶剂的量。In some embodiments, examples of the solvent include, but are not limited to, N-methylpyrrolidone, acetone, or water. In some embodiments, the amount of solvent can be adjusted appropriately.

在一些实施例中，所述集流体具有3微米至20微米范围内的厚度，但本公开内容不限于此。所述集流体没有特别的限制，只要所述集流体是导电的，而不在所制造的电池中引起不利的化学变化。所述集流体的实施例包括铜、不锈钢、铝、镍、钛或合金(例如铜-镍合金)，但公开内容不限于此。在一些实施例中，所述集流体的表面上可包括细小的不规则物(例如，表面粗糙度)以增强所述集流体的表面对活性物质的粘合。在一些实施例中，集流体可以多种形式使用，其实施例包括膜、片、箔、网、多孔结构体、泡沫体或无妨物，但本公开内容不限于此。In some embodiments, the current collector has a thickness in the range of 3 microns to 20 microns, although the disclosure is not limited thereto. The current collector is not particularly limited as long as the current collector is conductive without causing adverse chemical changes in the manufactured battery. Examples of the current collector include copper, stainless steel, aluminum, nickel, titanium, or alloys such as copper-nickel alloys, but the disclosure is not limited thereto. In some embodiments, fine irregularities (eg, surface roughness) may be included on the surface of the current collector to enhance adhesion of the surface of the current collector to the active material. In some embodiments, the current collector can be used in various forms, and examples thereof include films, sheets, foils, meshes, porous structures, foams, or similar materials, but the disclosure is not limited thereto.

隔离膜：在一些实施例中，以聚乙烯(简写为PE)多孔聚合薄膜作为隔离膜。在一些实施例中，所述隔离膜的材质可包括玻璃纤维，聚酯，聚乙烯，聚丙烯，聚四氟乙烯或其组合。在一些实施例中，所述隔离膜中的孔具有在0.01微米至1微米范围的直径，所述隔离膜的厚度在5微米至500微米范围内。Isolation film: In some embodiments, a polyethylene (abbreviated as PE) porous polymer film is used as the isolation film. In some embodiments, the material of the isolation membrane may include fiberglass, polyester, polyethylene, polypropylene, polytetrafluoroethylene or combinations thereof. In some embodiments, the pores in the isolation film have a diameter in the range of 0.01 micron to 1 micron, and the thickness of the isolation film ranges from 5 microns to 500 microns.

电解液：在一些实施例中，所述电解液包括有机溶剂、锂盐和添加剂。在一些实施例中，有机溶剂包括碳酸乙烯酯(简写为EC)、碳酸丙烯酯(简写为PC)、碳酸二乙酯(简写为DEC)、碳酸甲乙酯(简写为EMC)、碳酸二甲酯(简写为DMC)、碳酸亚丙酯或丙酸乙酯中的至少一种。在一些实施例中，锂盐包括有机锂盐或无机锂盐中的至少一种。在一些实施例中，锂盐包括六氟磷酸锂(LiPF ₆)、四氟硼酸锂(LiBF ₄)、二氟磷酸锂(LiPO ₂F ₂)、双三氟甲烷磺酰亚胺锂LiN(CF ₃SO ₂) ₂(LiTFSI)、双(氟磺酰)亚胺锂Li(N(SO ₂F) ₂)(LiFSI)、双草酸硼酸锂LiB(C ₂O ₄) ₂(LiBOB)或二氟草酸硼酸锂LiBF ₂(C ₂O ₄)(LiDFOB)中的至少一种。 Electrolyte: In some embodiments, the electrolyte includes an organic solvent, a lithium salt, and additives. In some embodiments, the organic solvent includes ethylene carbonate (abbreviated as EC), propylene carbonate (abbreviated as PC), diethyl carbonate (abbreviated as DEC), ethyl methyl carbonate (abbreviated as EMC), dimethyl carbonate At least one of ester (abbreviated as DMC), propylene carbonate or ethyl propionate. In some embodiments, the lithium salt includes at least one of an organic lithium salt or an inorganic lithium salt. In some embodiments, lithium salts include lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium difluorophosphate (LiPO ₂ F ₂ ), lithium bistrifluoromethanesulfonimide LiN (CF ₃ SO ₂ ) ₂ (LiTFSI), lithium bis(fluorosulfonyl)imide Li(N(SO ₂ F) ₂ )(LiFSI), lithium bis(fluorosulfonyl)borate LiB(C ₂ O ₄ ) ₂ (LiBOB) or lithium difluoroxalatoborate At least one of LiBF ₂ (C ₂ O ₄ ) (LiDFOB).

将正极、隔离膜、负极按顺序叠好，使隔离膜处于正负极中间起到隔离的作用，并卷绕得到裸电芯。将经卷绕所得裸电芯置于外包装中，注入电解液并封装，经过化成、脱气、切边等工艺流程获得锂离子电池。Stack the positive electrode, isolation film, and negative electrode in order so that the isolation film is between the positive and negative electrodes for isolation, and wind them to obtain a bare cell. The bare battery core obtained by winding is placed in an outer package, electrolyte is injected and packaged, and a lithium-ion battery is obtained through processes such as formation, degassing, and trimming.

三、电子装置3. Electronic devices

本申请提供了一种电子装置，其包含根据前述内容所述的电化学装置。The present application provides an electronic device comprising the electrochemical device according to the foregoing content.

根据本申请的一些实施例，所述电子装置包括，但不限于：笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池或锂离子电容器等。According to some embodiments of the present application, the electronic devices include, but are not limited to: notebook computers, pen-input computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, head-mounted Stereo headphones, video recorders, LCD TVs, portable cleaners, portable CD players, mini discs, transceivers, electronic notepads, calculators, memory cards, portable recorders, radios, backup power supplies, motors, cars, motorcycles, power-assisted bicycles , bicycles, lighting equipment, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries or lithium-ion capacitors, etc.

四、具体的实施例4. Specific Examples

下面结合实施例，对本申请做进一步详细的描述。然而，应理解，以下实施例仅是示例，本申请的实施例方式不限于此。The present application will be described in further detail below with reference to examples. However, it should be understood that the following embodiments are only examples, and the embodiments of the present application are not limited thereto.

实施例1至38和对比例1至2Examples 1 to 38 and Comparative Examples 1 to 2

正极的制作Production of positive electrode

步骤(1)：将无机颗粒、第一粘结剂、第一导电剂，以及可选的流平剂，加入水中混合均匀，获得保护层的浆料(在后称作“第一浆料”)；Step (1): Add inorganic particles, first binder, first conductive agent, and optional leveling agent to water and mix evenly to obtain a protective layer slurry (hereinafter referred to as "first slurry"). );

步骤(2)将步骤(1)中的第一浆料涂覆在正极集流体的目标区域；Step (2) Coating the first slurry in step (1) on the target area of the positive electrode current collector;

步骤(3)将步骤(2)中的获得的含有第一浆料的正极集流体进行烘干以去除溶剂，得到涂有保护层的正极集流体；Step (3) drying the positive electrode current collector containing the first slurry obtained in step (2) to remove the solvent to obtain a positive electrode current collector coated with a protective layer;

步骤(4)将活性物质(钴酸锂，质量百分比97.3％)、第二导电剂(质量百分比0.6％的导电碳(商品名Super P)和质量百分比0.5％的碳纳米管(简写为CNT)、第二粘结剂(质量百分比1.6％的聚偏氟乙烯(简写为PVDF))分散于N-甲基吡咯烷酮溶剂体系中充分搅拌混合均匀，得到正极活性物质的浆料(在后称作“第二浆料”)；Step (4) Combine the active material (lithium cobalt oxide, 97.3% by mass), the second conductive agent (0.6% by mass of conductive carbon (trade name Super P) and 0.5% by mass of carbon nanotubes (abbreviated as CNT) , the second binder (polyvinylidene fluoride (abbreviated as PVDF) with a mass percentage of 1.6%) is dispersed in the N-methylpyrrolidone solvent system and stirred thoroughly to obtain a slurry of the positive electrode active material (hereinafter referred to as " Second slurry");

步骤(5)将第二浆料涂覆在步骤(3)中得到的涂有保护层的正极集流体的目标区域；Step (5) applying the second slurry to the target area of the positive electrode current collector coated with the protective layer obtained in step (3);

步骤(6)将步骤(5)中的含有第二浆料的正极集流体进行烘干以去除溶剂，从而得到所要正极。Step (6) Drying the positive electrode current collector containing the second slurry in step (5) to remove the solvent, thereby obtaining the desired positive electrode.

下表1具体示出了实施例1至38和对比例1至2中的正极中的保护层差异。Table 1 below specifically shows the differences in protective layers in the positive electrodes in Examples 1 to 38 and Comparative Examples 1 to 2.

表1Table 1

除上述差异外，实施例1至38和对比例1至2中正极的正极活性材料层、正极集流体等并没有差异，均采用前述工艺制备。Except for the above differences, there are no differences in the positive active material layer, positive current collector, etc. of the positive electrodes in Examples 1 to 38 and Comparative Examples 1 to 2, and they are all prepared using the aforementioned process.

锂离子电池的制作Manufacturing of lithium-ion batteries

锂离子电池的正极的制作如前述。The positive electrode of the lithium-ion battery is produced as described above.

负极：将活性物质人造石墨、导电剂乙炔黑、粘结剂丁苯橡胶(简写为SBR)、增稠剂羧甲基纤维素钠(简写为CMC)按照质量比为95∶2∶2∶1在去离子水溶剂体系中充分搅拌混合均匀后，涂覆于Cu箔上烘干、冷压，得到负极。Negative electrode: Combine the active material artificial graphite, conductive agent acetylene black, binder styrene-butadiene rubber (abbreviated as SBR), and thickener sodium carboxymethylcellulose (abbreviated as CMC) in a mass ratio of 95:2:2:1 After being thoroughly stirred and mixed in a deionized water solvent system, it is coated on a Cu foil, dried, and cold-pressed to obtain a negative electrode.

电解液：在含水量＜10ppm的氩气气氛手套箱中，将碳酸乙烯酯(简写为EC)、碳酸二乙酯(简写为DEC)、碳酸丙烯酯(简写为PC)、按照2∶6∶2的重量比混合均匀，再将充分干燥的锂盐LiPF6溶解于上述溶剂，LiPF6的含量为12.5％，加入1.5％的1，3-丙烷磺内酯、3％的氟代碳酸乙烯酯、2％的己二腈。其中各物质含量是以电解液的总重量计。Electrolyte: In an argon atmosphere glove box with a water content of <10 ppm, mix ethylene carbonate (abbreviated as EC), diethyl carbonate (abbreviated as DEC), and propylene carbonate (abbreviated as PC) according to 2:6: Mix evenly with a weight ratio of 2, then dissolve the fully dried lithium salt LiPF6 in the above solvent, the content of LiPF6 is 12.5%, add 1.5% 1,3-propane sultone, 3% fluoroethylene carbonate, 2 % adiponitrile. The content of each substance is based on the total weight of the electrolyte.

隔离膜：以聚乙烯(简写为PE)多孔聚合薄膜作为隔离膜。Isolation film: Polyethylene (abbreviated as PE) porous polymer film is used as the isolation film.

将正极、隔离膜、负极按顺序叠好，使隔离膜处于正负极中间起到隔离的作用，并卷绕、置于外包装中，注入配好的电解液并封装，经过化成，脱气，切边等工艺得到锂离子电池。Stack the positive electrode, isolation film, and negative electrode in order, so that the isolation film is between the positive and negative electrodes for isolation, roll it up, place it in the outer package, inject the prepared electrolyte and package it, and then form and degas , trimming and other processes to obtain lithium-ion batteries.

性能测试方法Performance testing methods

颗粒度Graininess

采用激光粒度仪(马尔文3000)进行测试：仪器开机后，在样品仓内加入去离子水，先进行空白背景测试，当空白背景无明显特征峰时进行无机颗粒颗粒度的测试。将超声分散均匀的无机颗粒水分散液加入到样品仓内开始测试，即可获得无机颗粒的颗粒度分布情况，相关软件自动输出材料的颗粒度分布，并计算得到Dv5/Dv50/Dv90(样品的累积体积分布数分别达到5％/50％/90％时所对应的粒径)。Use a laser particle size analyzer (Malvern 3000) for testing: After the instrument is turned on, add deionized water to the sample chamber and conduct a blank background test first. When the blank background has no obvious characteristic peaks, conduct a particle size test of the inorganic particles. Add the aqueous dispersion of inorganic particles uniformly dispersed by ultrasonic into the sample chamber and start testing. The particle size distribution of the inorganic particles can be obtained. The relevant software automatically outputs the particle size distribution of the material and calculates Dv5/Dv50/Dv90 (sample's The corresponding particle size when the cumulative volume distribution number reaches 5%/50%/90% respectively).

保护层厚度Protective layer thickness

1)在(25±3)℃的环境下，将涂有保护层的正极从锂离子电池中拆出。用无尘纸拭去正极表面残留的电解液；1) Remove the positive electrode coated with protective layer from the lithium-ion battery in an environment of (25±3)℃. Use dust-free paper to wipe away the remaining electrolyte on the surface of the positive electrode;

2)在等离子体下切割涂有保护层的正极，得到其横截面；2) Cut the positive electrode coated with a protective layer under plasma to obtain its cross section;

3)在扫描电子显微镜(SEM)下观察2)中得到的正极的横截面，并测试保护层的厚度，相邻测试点间隔0.5mm至1mm，至少测试10个不同点，记所有测试点的均值为保护层的厚度H1μm。3) Observe the cross-section of the positive electrode obtained in 2) under a scanning electron microscope (SEM), and test the thickness of the protective layer. The intervals between adjacent test points are 0.5mm to 1mm. Test at least 10 different points, and record the values of all test points. The average value is the thickness of the protective layer H1μm.

锂离子电池内阻Lithium-ion battery internal resistance

使用电阻仪，采用正弦、1000Hz频率波测试锂离子电池的交流内阻。Use a resistance meter to test the AC internal resistance of the lithium-ion battery using sinusoidal and 1000Hz frequency waves.

高温存储内阻增长率High temperature storage internal resistance growth rate

存储条件(85℃放置6h)：Storage conditions (placed at 85°C for 6 hours):

在25±3℃的环境中，将锂离子电池以0.5C恒流充电至满充设计电压4.45V，再以满充电压4.45V恒压充电至0.025C，测试锂离子电池初始内阻记为IMP0。将锂离子电池放入85±3℃的高温炉中6h后取出，待锂离子电池温度降至25±3℃后，测试其内阻记为“IMP6h”。高温存储内阻增长率＝(IMP6h-IMP0)/IMP0×100％。In an environment of 25±3°C, charge the lithium-ion battery at a constant current of 0.5C to the full charge design voltage of 4.45V, and then charge at a constant voltage of 4.45V to the full charge voltage to 0.025C. The initial internal resistance of the tested lithium-ion battery is recorded as imp0. Put the lithium-ion battery into a high-temperature furnace at 85±3℃ for 6 hours and take it out. After the temperature of the lithium-ion battery drops to 25±3℃, test its internal resistance and record it as "IMP6h". High temperature storage internal resistance growth rate=(IMP6h-IMP0)/IMP0×100%.

满充状态下的正极电阻Positive resistance in fully charged state

1)0.05C的倍率恒流充电至满充设计电压4.45V，随后以满充设计电压4.45V恒压充电至电流为0.025C(截止电流)，使锂离子电池达到满充状态；1) Charge with a constant current at a rate of 0.05C to the full charge design voltage of 4.45V, and then charge with a constant voltage of the full charge design voltage of 4.45V until the current is 0.025C (cut-off current), so that the lithium-ion battery reaches the full charge state;

2)将锂离子电池拆解，得到正极；2) Disassemble the lithium-ion battery to obtain the positive electrode;

3)将2)中所得正极在湿度为5％至15％的环境中放置30min，然后密封转移到电阻测试地点；3) Place the positive electrode obtained in 2) in an environment with a humidity of 5% to 15% for 30 minutes, and then seal and transfer it to the resistance test location;

4)使用BER1200型号膜片电阻测试仪测试3)中所得正极的电阻，相邻测试点间隔2mm至3mm，至少测试15个不同点，所有测试点的电阻均值记为满充状态下的正极电阻RΩ，其中测试参数为：压头面积153.94mm2，压力3.5t，保持时间50s。4) Use the BER1200 diaphragm resistance tester to test the resistance of the positive electrode obtained in 3). The distance between adjacent test points is 2mm to 3mm. Test at least 15 different points. The average resistance of all test points is recorded as the positive electrode resistance in the fully charged state. RΩ, where the test parameters are: pressure head area 153.94mm2, pressure 3.5t, holding time 50s.

侧边挤压通过率Side extrusion pass rate

将待测的锂离子电池以0.05C的倍率恒流充电至设计满充电压4.45V，随后以满充设计电压4.45V恒压充电至电流为0.025C(截止电流)，使锂离子电池达到满充状态，记录测试前锂离子电池外观。在25±3℃环境中对电池进行侧边挤压测试，钢钉直径5mm，挤压速度150mm/s，从锂离子电池垂直于极耳所在一侧的侧边开始挤压，测试进行3min或锂离子电池表面温度降到50℃以后停止测试，以20个锂离子电池为一组，观察测试过程中锂离子电池状态，以锂离子电池不燃烧、不***为通过标准。记侧边挤压通过率＝通过数/20。Charge the lithium-ion battery to be tested with a constant current at a rate of 0.05C to the designed full charge voltage of 4.45V, and then charge with a constant voltage of 4.45V at the full design voltage until the current is 0.025C (cut-off current), so that the lithium-ion battery reaches full charge. Charging status, record the appearance of the lithium-ion battery before testing. Conduct a side extrusion test on the battery in an environment of 25±3°C. The diameter of the steel nail is 5mm and the extrusion speed is 150mm/s. The extrusion starts from the side of the lithium-ion battery perpendicular to the side where the tab is located. The test lasts for 3 minutes or The test is stopped after the surface temperature of the lithium-ion battery drops to 50°C. A group of 20 lithium-ion batteries is used to observe the status of the lithium-ion battery during the test. The passing criterion is that the lithium-ion battery does not burn or explode. Record the side extrusion pass rate = the number of passes/20.

下表2示出了实施例1至38和对比例1至2的各项性能。Table 2 below shows various properties of Examples 1 to 38 and Comparative Examples 1 to 2.

表2Table 2

1.探讨保护层的有无和无机颗粒粒径对电化学装置的性能影响1. Explore the impact of the presence or absence of a protective layer and the particle size of inorganic particles on the performance of electrochemical devices

由前述表1和表2可知，具有保护层的实施例1至38以及具有保护层的对比例2的锂离子电池的侧边挤压通过率明显优于没有保护层的对比例1的锂离子电池。由此可见，正极集流体与正极活性材料层之间加入的保护层可以显著提高锂离子电池的安全性能。It can be seen from the aforementioned Table 1 and Table 2 that the side extrusion pass rate of the lithium ion batteries of Examples 1 to 38 with a protective layer and Comparative Example 2 with a protective layer is significantly better than that of the lithium ion battery of Comparative Example 1 without a protective layer. Battery. It can be seen that the protective layer added between the positive electrode current collector and the positive electrode active material layer can significantly improve the safety performance of lithium-ion batteries.

由前述表1和表2中的实施例1至38与对比例2的比较可知，当所述保护层的无机颗粒满足Dv5≤0.5μm时(其中，Dv5表示所述无机颗粒的累积体积分布数达到5％时对应的粒径)，锂离子电池能够具有较高的侧边挤压通过率(70％以上)，这是由于，通过控制保护层中的无机颗粒满足Dv5≤0.5um，能够使无机颗粒更均匀、全面的覆盖正极集流体，特别是在卷绕结构的拐角处，能够具有充足的小粒径无机颗粒进行填充，从而更好地覆盖拐角处的正极集流体；且在锂离子电池受到侧边挤压时，保护层随着极片的弯曲而存在内应力，特别是在卷绕结构的拐角处，由于拐角处自身存在弯曲应力，在受到侧边挤压时，应力将更加集中，保护层中的小粒径无机颗粒可以促进无机颗粒之间的滑移，降低内应力，从而抑制保护层脱落，进而降低了正极集流体与负极活性材料层之间的短路风险，提高了锂离子电池的侧边挤压通过率。It can be seen from the comparison between Examples 1 to 38 and Comparative Example 2 in the aforementioned Table 1 and Table 2 that when the inorganic particles of the protective layer satisfy Dv5 ≤ 0.5 μm (where Dv5 represents the cumulative volume distribution number of the inorganic particles When reaching the corresponding particle size of 5%), lithium-ion batteries can have a high side extrusion pass rate (more than 70%). This is because by controlling the inorganic particles in the protective layer to satisfy Dv5≤0.5um, it can make The inorganic particles more uniformly and comprehensively cover the cathode current collector, especially at the corners of the rolled structure, which can be filled with sufficient small-sized inorganic particles to better cover the cathode current collector at the corners; and in lithium ion When the battery is squeezed from the side, the protective layer will have internal stress as the pole piece bends, especially at the corners of the winding structure. Due to the bending stress at the corner itself, the stress will be even greater when it is squeezed from the side. Concentrated, small-sized inorganic particles in the protective layer can promote slippage between inorganic particles, reduce internal stress, thereby inhibiting the shedding of the protective layer, thereby reducing the risk of short circuit between the positive electrode current collector and the negative electrode active material layer, and improving Side crush pass rate of lithium-ion batteries.

进一步地，由前述表1和表2中的实施例1至36与实施例37的比较可知，当所述保护层的无机颗粒满足Dv50/H1≤0.4时，锂离子电池能够具有更加优异的侧边挤压通过率(90％以上)。这是由于，在锂离子电池受到侧边挤压时，能够具有充足的无机颗粒在保护层的厚度方向上相互滑移，从而进一步降低保护层内部的应力，抑制保护层的脱落，从而降低正极集流体和负极活性材料层之间短路的风险，进而进一步提高锂离子电池的侧边挤压通过率。Further, from the comparison of Examples 1 to 36 and Example 37 in Table 1 and Table 2, it can be seen that when the inorganic particles of the protective layer satisfy Dv50/H1≤0.4, the lithium ion battery can have more excellent side effects. Side extrusion pass rate (more than 90%). This is because when the lithium-ion battery is squeezed from the side, sufficient inorganic particles can slide with each other in the thickness direction of the protective layer, thereby further reducing the stress inside the protective layer, inhibiting the shedding of the protective layer, and thereby reducing the risk of cathode damage. The risk of short circuit between the current collector and the negative active material layer further increases the side extrusion pass rate of lithium-ion batteries.

2.探讨保护层的组成对电化学装置的性能的影响2. Explore the impact of the composition of the protective layer on the performance of the electrochemical device

2.1无机颗粒2.1 Inorganic particles

本申请实施例1至38中保护层所用的无机颗粒可包括第一颗粒和/或第二颗粒。第一颗粒包括勃姆石、氧化铝、硫酸钡、硫酸钙或硅酸钙中的至少一种。第二颗粒包括磷酸铁锂、磷酸锰铁锂、锰酸锂中的至少一种。然而，应当理解，本申请保护层所用的无机颗粒不限于具体实施例所列举的种类，其可以包含其类似物。The inorganic particles used in the protective layer in Examples 1 to 38 of the present application may include first particles and/or second particles. The first particles include at least one of boehmite, aluminum oxide, barium sulfate, calcium sulfate or calcium silicate. The second particles include at least one of lithium iron phosphate, lithium iron manganese phosphate, and lithium manganate. However, it should be understood that the inorganic particles used in the protective layer of the present application are not limited to the types listed in the specific embodiments, and may include their analogs.

2.2第一粘结剂2.2 First binder

本申请实施例1至38中保护层所用的第一粘结剂可包括丙烯腈-丙烯酸锂-丙烯酰胺聚合物、聚丙烯酸、羧甲基纤维素钠、聚丙烯酸钠、聚丙烯酸酯、聚丙烯腈或丁腈橡胶中的至少一种。然而，应当理解，本申请保护层所用的第一粘结剂不限于具体实施例所列举的种类，其可以包含丙烯酸、丙烯酰胺、丙烯酸盐、丙烯腈或丙烯酸酯中的至少一种形成的聚合物。The first binder used for the protective layer in Examples 1 to 38 of the present application may include acrylonitrile-lithium acrylate-acrylamide polymer, polyacrylic acid, sodium carboxymethylcellulose, sodium polyacrylate, polyacrylate, polypropylene At least one of nitrile or nitrile rubber. However, it should be understood that the first adhesive used in the protective layer of the present application is not limited to the types listed in the specific embodiments. It may include a polymer formed from at least one of acrylic acid, acrylamide, acrylate, acrylonitrile or acrylate. things.

由前述表1和表2中的实施例1至37与实施例38、对比例2的比较可发现，当保护层包含的第一粘结剂为水性粘结剂时，其相较于聚四氟乙烯、聚偏氟乙烯，能够显著改善锂离子电池的高温存储内阻增长率。Comparing Examples 1 to 37 with Example 38 and Comparative Example 2 in Table 1 and Table 2, it can be found that when the first binder contained in the protective layer is a water-based binder, it is Vinyl fluoride and polyvinylidene fluoride can significantly improve the high-temperature storage internal resistance growth rate of lithium-ion batteries.

2.3流平剂2.3 Leveling agent

本申请实施例1至38中保护层所用的流平剂可包括乙氧基丙烯-丙氧基丙烯共聚物、聚二甲基硅烷、丙烯酸酯聚合物、丙烯酸钠聚合物或氟碳改性聚丙烯酸酯中的至少一种。然而，应当理解，本申请保护层所用的流平剂不限于具体实施例所列举的种类，其可以包含其类似物。The leveling agent used in the protective layer in Examples 1 to 38 of the present application may include ethoxypropylene-propoxypropylene copolymer, polydimethylsilane, acrylate polymer, sodium acrylate polymer or fluorocarbon modified polyethylene. At least one kind of acrylate. However, it should be understood that the leveling agent used in the protective layer of the present application is not limited to the types listed in the specific embodiments, and may include analogs thereof.

由前述表1和表2中的实施例31至35与实施例36的比较可发现，当保护层有包含流平剂时，其相较于不包含者，其改善高温存储内阻增长率的效果更明显。From the comparison between Examples 31 to 35 and Example 36 in the aforementioned Table 1 and Table 2, it can be found that when the protective layer contains a leveling agent, it improves the growth rate of the internal resistance in high-temperature storage compared to the case where it does not contain a leveling agent. The effect is more obvious.

综上所述，本申请的电化学装置可具有较高的侧边挤压通过率，即具有优异的安全性；且可保持高温存储内阻增长率在一定的范围内，具有良好的高温稳定性。In summary, the electrochemical device of the present application can have a high side extrusion pass rate, that is, it has excellent safety; and it can maintain the growth rate of high-temperature storage internal resistance within a certain range, and has good high-temperature stability. sex.

整个说明书中对“一些实施例”、“部分实施例”、“一个实施例”、“另一举例”、“举例”、“具体举例”或“部分举例”的引用，其所代表的意思是在本申请中的至少一个实施例或举例包含了该实施例或举例中所描述的特定特征、结构、材料或特性。因此，在整个说明书中的各处所出现的描述，例如：“在一些实施例中”、“在实施例中”、“在一个实施例中”、“在另一个举例中”，“在一个举例中”、“在特定举例中”或“举例“，其不必然是引用本申请中的相同的实施例或示例。此外，本文中的特定特征、结构、材料或特性可以以任何合适的方式在一个或多个实施例或举例中结合。References throughout this specification to “some embodiments,” “partial embodiments,” “one embodiment,” “another example,” “example,” “specific example,” or “partial example” mean the following: At least one embodiment or example in this application includes a specific feature, structure, material or characteristic described in the embodiment or example. Accordingly, phrases such as "in some embodiments," "in an embodiment," "in one embodiment," "in another example," "in one example," etc. may appear in various places throughout this specification. "in", "in a particular example" or "for example" do not necessarily refer to the same embodiment or example in this application. Furthermore, the specific features, structures, materials, or characteristics herein may be combined in any suitable manner in one or more embodiments or examples.

尽管已经演示和描述了说明性实施例，本领域技术人员应该理解上述实施例不能被解释为对本申请的限制，并且可以在不脱离本申请的精神、原理及范围的情况下对实施例进行改变，替代和修改。Although illustrative embodiments have been shown and described, those skilled in the art will understand that the above-described embodiments are not to be construed as limitations of the present application, and that changes may be made in the embodiments without departing from the spirit, principles and scope of the present application. , substitutions and modifications.

Claims

一种电化学装置，其包括：正极，所述正极包括正极集流体、保护层和正极活性材料层，所述保护层设置于所述正极集流体与所述正极活性材料层之间；所述保护层包含无机颗粒，采用激光粒度仪进行测试，所述无机颗粒满足Dv5≤0.5μm，其中，Dv5表示所述无机颗粒的累积体积分布数达到5％时所对应的粒径。An electrochemical device, which includes: a positive electrode, the positive electrode includes a positive electrode current collector, a protective layer and a positive electrode active material layer, the protective layer is disposed between the positive electrode current collector and the positive electrode active material layer; The protective layer contains inorganic particles, which are tested using a laser particle size analyzer. The inorganic particles satisfy Dv5 ≤ 0.5 μm, where Dv5 represents the particle size corresponding to when the cumulative volume distribution number of the inorganic particles reaches 5%.
根据权利要求1所述的电化学装置，其中，所述保护层的厚度为H1μm，满足如下条件中的至少一者：The electrochemical device according to claim 1, wherein the thickness of the protective layer is H1 μm and meets at least one of the following conditions:

(a)Dv50/H1≤0.4，其中，Dv50表示采用激光粒度仪进行测试，所述无机颗粒的累积体积分布数达到50％时所对应的粒径，单位为μm；(a) Dv50/H1≤0.4, where Dv50 represents the particle size corresponding to when the cumulative volume distribution number of the inorganic particles reaches 50% when tested using a laser particle size analyzer, the unit is μm;

(b)Dv90/H1＜1，其中，Dv90表示所述无机颗粒的累积体积分布数达到90％时所对应的粒径，单位为μm；(b) Dv90/H1<1, where Dv90 represents the particle diameter corresponding to when the cumulative volume distribution number of the inorganic particles reaches 90%, in μm;

(c)0.5≤H1≤10。(c)0.5≤H1≤10.
根据权利要求1所述的电化学装置，其中，所述无机颗粒包含第一颗粒和/或第二颗粒，满足如下条件中的至少一者：The electrochemical device according to claim 1, wherein the inorganic particles comprise first particles and/or second particles that meet at least one of the following conditions:

(1)所述第一颗粒包含A元素，所述A元素包含Al、Mg、Si、Ca、Ti、Ce、Zn、Y、Hf、Zr、Ba或Sn中的至少一种；(1) The first particles contain A element, and the A element contains at least one of Al, Mg, Si, Ca, Ti, Ce, Zn, Y, Hf, Zr, Ba or Sn;

(2)所述第二颗粒包含Li元素和M元素，所述M元素包含Mn或Fe中的至少一种。(2) The second particles include Li element and M element, and the M element includes at least one of Mn or Fe.
根据权利要求3所述的电化学装置，其满足如下条件中的至少一者：The electrochemical device according to claim 3, which satisfies at least one of the following conditions:

(i)所述第一颗粒包含氧化铝、氧化镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化锌、氧化钙、氧化锆、氧化钇、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙、硅酸钙、硬水铝石、硫酸钡、硫酸钙或硅酸钙中的至少一种；(i) The first particles include aluminum oxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, ceria, zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, boehmite, aluminum hydroxide, hydrogen At least one of magnesium oxide, calcium hydroxide, calcium silicate, diaspore, barium sulfate, calcium sulfate or calcium silicate;

(ii)所述第二颗粒包含磷酸铁锂、磷酸锰铁锂或锰酸锂中的至少一种。(ii) The second particles comprise at least one of lithium iron phosphate, lithium iron manganese phosphate or lithium manganate.
根据权利要求1所述的电化学装置，其中，所述保护层包含粘结剂，所述粘结剂满足如下特征中的至少一者：The electrochemical device according to claim 1, wherein the protective layer includes a binder, the binder satisfies at least one of the following characteristics:

(I)所述粘结剂为水性粘结剂；(1) The adhesive is a water-based adhesive;

(II)所述粘结剂包含丙烯酸、丙烯酸盐、丙烯腈、丙烯酰胺或丙烯酸酯中的至少一种形成的聚合物；(II) The binder includes a polymer formed from at least one of acrylic acid, acrylate, acrylonitrile, acrylamide or acrylate;

(III)所述粘结剂包含羧甲基纤维素盐或丁腈橡胶中的至少一种；(III) The binder includes at least one of carboxymethyl cellulose salt or nitrile rubber;

(IV)所述粘结剂的重量平均分子量为18万至220万。(IV) The weight average molecular weight of the binder is 180,000 to 2.2 million.
根据权利要求1所述的电化学装置，其中，所述保护层还包含导电剂，满足如下特征中的至少一者：The electrochemical device according to claim 1, wherein the protective layer further includes a conductive agent that meets at least one of the following characteristics:

(1)所述导电剂包含片层状、网状、线状或颗粒状导电剂中的至少一种；(1) The conductive agent includes at least one of sheet-like, mesh-like, linear or granular conductive agents;

(2)基于所述保护层的质量，所述导电剂的质量百分比为0.3％至20％。(2) Based on the mass of the protective layer, the mass percentage of the conductive agent is 0.3% to 20%.
根据权利要求2所述的电化学装置，其中，满足如下条件中的至少一者：The electrochemical device according to claim 2, wherein at least one of the following conditions is met:

(1)0.1≤Dv50≤1.5；(1)0.1≤Dv50≤1.5;

(2)0.4≤Dv90≤3.5。(2)0.4≤Dv90≤3.5.
根据权利要求1所述的电化学装置，其中，所述保护层还包含流平剂，所述流平剂满足如下特征中的至少一者：The electrochemical device according to claim 1, wherein the protective layer further includes a leveling agent, and the leveling agent satisfies at least one of the following characteristics:

(1)基于所述保护层的质量，所述流平剂的质量百分比为大于0％且小于或者等于6％；(1) Based on the mass of the protective layer, the mass percentage of the leveling agent is greater than 0% and less than or equal to 6%;

(2)所述流平剂包括硅氧烷类化合物、硅氧烷类衍生物、含氧烯烃聚合物、丙烯酸酯类聚合物、丙烯酸盐类聚合物、醇类化合物、醚类化合物或氟碳化合物中的至少一种。(2) The leveling agent includes silicone compounds, silicone derivatives, oxygen-containing olefin polymers, acrylate polymers, acrylate polymers, alcohol compounds, ether compounds or fluorocarbons at least one of the compounds.
根据权利要求1所述的电化学装置，其中，所述电化学装置在满充状态下，所述正极的电阻为RΩ，满足1≤R≤10。The electrochemical device according to claim 1, wherein when the electrochemical device is fully charged, the resistance of the positive electrode is RΩ, satisfying 1≤R≤10.
一种电子装置，其包括根据权利要求1-9中任一项所述的电化学装置。An electronic device comprising the electrochemical device according to any one of claims 1-9.