WO2021046719A1

WO2021046719A1 - Method for preparing secondary battery

Info

Publication number: WO2021046719A1
Application number: PCT/CN2019/105182
Authority: WO
Inventors: 唐永炳; 欧学武; 张阁; 向立
Original assignee: Shenzhen Institute of Advanced Technology of CAS
Current assignee: Shenzhen Institute of Advanced Technology of CAS
Priority date: 2019-09-10
Filing date: 2019-09-10
Publication date: 2021-03-18
Anticipated expiration: 2022-03-10

Abstract

Disclosed is a method for preparing a secondary battery, the method comprising: assembling a first positive plate (2), a first diaphragm (3), a first negative plate (4), a first electrolyte, and a first packaging shell (1) to prepare a primary battery; performing charging and discharging circulation on the primary battery; then disassembling the primary battery, and taking out the first positive plate (2) subjected to surface passivation treatment; obtaining a second positive plate (7), wherein the second positive plate (7) comprises a second positive material and a second positive current collector, the second positive material is the same as or different from the first positive material, and the second positive current collector is a first positive current collector with the surface subjected to passivation treatment; and assembling the second positive plate (7), a second diaphragm (8), a second negative plate (9), a second electrolyte, and a second packaging shell (6) to prepare the secondary battery, wherein the second electrolyte contains a bis(fluorosulfonyl)imide salt and/or a bis(trifluoromethanesulfonyl)imide salt. The secondary battery prepared by using the preparation method can effectively inhibit corrosion of the positive current collector by the electrolyte containing FSI and TFSI.

Description

Preparation method of secondary battery

Technical field

本申请涉及电池技术领域，具体涉及一种二次电池的制备方法。This application relates to the technical field of batteries, and in particular to a method for preparing secondary batteries.

Background technique

锂离子电池现已广泛应用于生活中的各个方面，作为一种典型的二次电池，锂离子电池主要由正极、负极、隔膜、电解液等主要部分组成。充电时，锂离子从正极材料中脱出，迁移到负极活性材料中；放电时，锂离子从负极活性材料中脱出，回到正极。在锂离子电池的“摇椅式”工作过程中，电解液主要起到传输离子的作用。传统的锂离子电池电解液通常以LiPF ₆作为电解质盐以及碳酸酯类作为溶剂(浓度为1mol/L)。尽管这一电解液配方已经广泛使用在锂离子电池中，然而其在稳定性、安全性等方面的问题日益突出。譬如，LiPF ₆在含有微量水的条件下会发生分解产生HF，HF会腐蚀正极材料，从而造成活性物质的丢失和结构的破坏。 Lithium-ion batteries are now widely used in all aspects of life. As a typical secondary battery, lithium-ion batteries are mainly composed of a positive electrode, a negative electrode, a separator, and an electrolyte. When charging, lithium ions are removed from the positive electrode material and migrate to the negative electrode active material; when discharging, lithium ions are removed from the negative electrode active material and return to the positive electrode. In the "rocking chair" working process of lithium-ion batteries, the electrolyte mainly plays a role in transmitting ions. Traditional lithium-ion battery electrolytes usually use LiPF ₆ as the electrolyte salt and carbonates as the solvent (with a concentration of 1 mol/L). Although this electrolyte formulation has been widely used in lithium-ion batteries, its stability and safety problems have become increasingly prominent. For example, LiPF ₆ will decompose to produce HF under the condition of containing a small amount of water. HF will corrode the cathode material, resulting in the loss of active material and structural damage.

相比较于LiPF ₆，基于双氟磺酰亚胺盐(FSI ^-)、双(三氟甲基磺酰)亚胺盐(TFSI ^-)等电解质的电解液越来越受到人们的关注。FSI ^-和TFSI ^-等电解质稳定性高，不易发生分解。另外，FSI ^-和TFSI ^-等电解质在传统碳酸酯类溶剂中容易解离，离子电导率高，溶解度高。譬如，LiFSI在碳酸二甲酯中的溶解度可以达到5.5mol/L，LiFSI在氟化碳酸乙烯酯中的溶解度可以达到7mol/L。高的离子电导率有利于电池实现快速的充放电，而高浓度有利于提高电解液的电化学窗口、安全性等。特别的，对于双离子电池，由于电解液作为活性物质的一部分，高浓度电解液有利于提高电池的能量密度。因此，基于FSI ^-和TFSI ^-等电解质的电解液具有广泛的应用前景。然而，以双氟磺酰亚胺盐和/或双(三氟甲基磺酰)亚胺盐为电解质的二次电池中，其正极集流体的腐蚀问题较为严重，即使使用传统认为耐腐蚀的钛箔、不锈钢、甚至是金属铂片作为正极集流体，其腐蚀问题依然存在。 Compared to LiPF _6, based on double salt of fluorosulfonylimide (FSI ^-), bis (trifluoromethanesulfonyl) imide (TFSI ^-) the electrolyte of the electrolyte more and more attention. Electrolytes such as FSI ^- and TFSI ^- have high stability and are not easily decomposed. In addition, ^{electrolytes such as FSI-} and TFSI ^- are easily dissociated in traditional carbonate solvents, with high ionic conductivity and high solubility. For example, the solubility of LiFSI in dimethyl carbonate can reach 5.5 mol/L, and the solubility of LiFSI in fluorinated ethylene carbonate can reach 7 mol/L. The high ionic conductivity is conducive to rapid charging and discharging of the battery, and the high concentration is conducive to improving the electrochemical window and safety of the electrolyte. In particular, for dual-ion batteries, since the electrolyte is part of the active material, high-concentration electrolyte is beneficial to increase the energy density of the battery. Therefore, electrolytes based on electrolytes such as ^FSI- and TFSI ^{-have broad application prospects.} However, in the secondary battery using bisfluorosulfonimide salt and/or bis(trifluoromethylsulfonyl)imide salt as the electrolyte, the corrosion problem of the positive current collector is more serious, even if the traditionally considered corrosion-resistant The corrosion problem of titanium foil, stainless steel, and even metal platinum sheet as the positive electrode current collector still exists.

为了解决基于FSI ^-和TFSI ^-等电解质的电解液对正极集流体的腐蚀问题，传统的手段包括配制超高浓度的电解液、电解液的杂化以及采用耐腐蚀的材料如TiN、TiB ₂等处理的不锈钢片等。然而，超高浓度的电解液往往粘度很大，造成电极浸润性差，电池充放电倍率性能有限等问题。电解液的杂化通常难以实现有效钝化正极金属集流体的效果。采用耐腐蚀的材料如TiN、TiB ₂等处理的不锈钢片，其工艺过程复杂，成本较高；且在长循环的过程中，这种镀层仍然会发生明显的腐蚀。 In order to solve ^{the corrosion problem of electrolytes based on FSI-} and TFSI ^- on the cathode current collector, traditional methods include the preparation of ultra-high concentration electrolytes, the hybridization of electrolytes, and the use of corrosion-resistant materials such as TiN, TiB _2, etc. Processed stainless steel sheets, etc. However, ultra-high-concentration electrolytes are often very viscous, causing problems such as poor electrode wettability and limited battery charge-discharge rate performance. The hybridization of electrolyte is usually difficult to achieve the effect of effectively passivating the positive electrode metal current collector. The stainless steel sheet treated with corrosion-resistant materials such as TiN and TiB ₂ has a complicated process and high cost; and in the process of a long cycle, the coating will still be significantly corroded.

发明概述Summary of the invention

technical problem

本申请实施例的目的之一在于：提供一种二次电池的制备方法，以制备一种可有效抑制含FSI ^-和TFSI ^-的电解液腐蚀正极集流体的二次电池。 One of the objectives of the embodiments of the present application is to provide a method for preparing a secondary battery, so as to prepare a secondary battery that can effectively inhibit the corrosion of the positive electrode current collector by the electrolyte ^{containing FSI-} and TFSI ^-.

问题的解决方案The solution to the problem

Technical solutions

为解决上述技术问题，本申请实施例采用的技术方案是：In order to solve the above technical problems, the technical solutions adopted in the embodiments of this application are:

第一方面，提供了一种二次电池的制备方法，包括以下步骤：In the first aspect, a method for preparing a secondary battery is provided, which includes the following steps:

将第一正极片与第一隔膜、第一负极片、第一电解液和第一封装外壳进行组装，制备第一电池；所述第一正极片包括第一正极材料和第一正极集流体，所述第一电解液在所述第一电池的充放电循环过程中能够表面钝化所述第一正极集流体；Assemble the first positive electrode sheet with the first separator, the first negative electrode sheet, the first electrolyte and the first packaging shell to prepare a first battery; the first positive electrode sheet includes a first positive electrode material and a first positive electrode current collector, The first electrolyte can surface passivate the first positive electrode current collector during the charge and discharge cycle of the first battery;

将所述第一电池进行充放电循环，对所述第一正极片进行表面钝化处理，使得所述第一正极集流体的表面形成钝化层；然后，拆解所述第一电池，取出经过表面钝化处理的第一正极片；The first battery is subjected to a charge-discharge cycle, and the first positive electrode sheet is subjected to a surface passivation treatment, so that a passivation layer is formed on the surface of the first positive electrode current collector; then, the first battery is disassembled and taken out The first positive electrode plate with surface passivation treatment;

获取第二正极片，所述第二正极片包括：第二正极材料和第二正极集流体，所述第二正极材料与所述第一正极材料相同或不相同，所述第二正极集流体为所述表面经过钝化处理的第一正极集流体；Obtain a second positive electrode sheet, the second positive electrode sheet comprising: a second positive electrode material and a second positive electrode current collector, the second positive electrode material is the same or different from the first positive electrode material, and the second positive electrode current collector Is the first positive electrode current collector whose surface has been passivated;

将所述第二正极片与第二隔膜、第二负极片、第二电解液和第二封装外壳进行组装，所述第二电解液包含双氟磺酰亚胺盐和/或双(三氟甲基磺酰)亚胺盐，制备所述二次电池。Assemble the second positive electrode sheet with the second separator, the second negative electrode sheet, the second electrolyte and the second packaging shell, and the second electrolyte contains bis(fluorosulfonimide) salt and/or bis(trifluorocarbon). Methylsulfonyl)imide salt to prepare the secondary battery.

第二方面，提供了一种由上述制备方法制得的二次电池。In a second aspect, a secondary battery prepared by the above preparation method is provided.

本申请实施例中，将第一正极片与对第一正极集流体具有钝化作用的第一电解液组装形成第一电池，然后对第一电池进行充放电循环，以获得经过表面钝化处理的第一正极片，在此基础上，将其与包含双氟磺酰亚胺盐和/或双(三氟甲基磺酰)亚胺盐的第二电解液重新组装，从而制备获得一种可有效抑制含FSI-和TFSI-的电解液腐蚀正极集流体的二次电池，其具有良好的安全性能和电化学性能。与现有技术相比，本申请的制备方法，步骤简单，成本低，具有良好的重复性和可控性，且抗腐蚀效果明显，促进了基于FSI-和TFSI-等电解质的二次电池的广泛应用。In the embodiment of the present application, the first positive electrode sheet is assembled with the first electrolyte that has a passivating effect on the first positive electrode current collector to form the first battery, and then the first battery is subjected to a charge and discharge cycle to obtain a passivated surface. On this basis, it is reassembled with a second electrolyte containing bisfluorosulfonimide salt and/or bis(trifluoromethylsulfonyl)imide salt to prepare a It can effectively inhibit the electrolyte containing FSI- and TFSI- from corroding the secondary battery of the cathode current collector, and it has good safety performance and electrochemical performance. Compared with the prior art, the preparation method of the present application has simple steps, low cost, good repeatability and controllability, and obvious anti-corrosion effect, which promotes the development of secondary batteries based on electrolytes such as FSI- and TFSI- widely used.

发明的有益效果The beneficial effects of the invention

对附图的简要说明Brief description of the drawings

Description of the drawings

为了更清楚地说明本申请实施例中的技术方案，下面将对实施例或示范性技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其它的附图。In order to more clearly describe the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings that need to be used in the embodiments or exemplary technical descriptions. Obviously, the accompanying drawings in the following description are only of the present application. For some embodiments, those of ordinary skill in the art can obtain other drawings based on these drawings without creative work.

图1为实施例1制得的第一电池的主体部分的剖面结构；Figure 1 is a cross-sectional structure of the main body of the first battery made in Example 1;

图2为实施例2制得的锂离子电池的主体部分的剖面结构；2 is a cross-sectional structure of the main part of the lithium ion battery prepared in Example 2;

图3为实施例43制备表面钝化的正极片和正极壳的步骤4)中的充放电曲线；3 is the charge and discharge curve in step 4) of preparing a positive electrode sheet and a positive electrode case with a passivation surface in Example 43;

图4为实施例43制得的Li-石墨双离子电池在3-5V的电压范围内、以400mA/g进行充放电的循环性能测试结果；FIG. 4 shows the cycle performance test results of the Li-graphite dual-ion battery prepared in Example 43 in the voltage range of 3-5V and 400mA/g for charging and discharging;

图5为实施例44制得的Li-石墨双离子电池在3-5V的电压范围内、以200mA/g进行充放电的循环性能测试结果；FIG. 5 is a test result of the cycle performance of the Li-graphite dual-ion battery prepared in Example 44 in the voltage range of 3-5V and charged and discharged at 200mA/g;

图6为对比例1制得的第一电池以电流密度为200mA/g、电压为3-5V进行充放电循环的循环性能测试结果；Figure 6 shows the cycle performance test results of the first battery made in Comparative Example 1 with a current density of 200mA/g and a voltage of 3-5V for charging and discharging cycles;

图7为对比例1中正极铝箔在5V电压下保持10小时后其表面的电镜扫描图像；Fig. 7 is an electron microscope scan image of the surface of the positive electrode aluminum foil in Comparative Example 1 after being kept at a voltage of 5V for 10 hours;

图8为对比例2制得的第一电池以电流密度为200mA/g、电压为3-5V进行充放电循环的循环性能测试结果；Fig. 8 is a cycle performance test result of the first battery prepared in Comparative Example 2 with a current density of 200mA/g and a voltage of 3-5V for charging and discharging cycles;

图9为对比例2中正极铝箔在5V电压下保持10小时后其表面的电镜扫描图像。Fig. 9 is a scanning electron microscope image of the surface of the positive electrode aluminum foil in Comparative Example 2 after being kept at a voltage of 5V for 10 hours.

附图标记：第一正极壳1，第一正极片2，第一隔膜3，第一负极片4，第一负极壳5，第二正极壳6，第二正极片7，第二隔膜8，第二负极片9，第二负极壳10。Reference signs: first positive electrode case 1, first positive electrode sheet 2, first separator 3, first negative electrode sheet 4, first negative electrode case 5, second positive electrode case 6, second positive electrode sheet 7, second separator 8, The second negative electrode sheet 9 and the second negative electrode case 10.

发明实施例Invention embodiment

Embodiments of the present invention

为了使本申请的目的、技术方案及优点更加清楚明白，以下结合附图及实施例，对本申请进行进一步详细说明。应当理解，此处所描述的具体实施例仅用以解释本申请，并不用于限定本申请。In order to make the purpose, technical solutions, and advantages of this application clearer, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, and are not used to limit the present application.

为了说明本申请所述的技术方案，以下结合具体附图及实施例进行详细说明。In order to illustrate the technical solutions described in this application, detailed descriptions are given below in conjunction with specific drawings and embodiments.

在本申请的描述中，需要理解的是，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括一个或者更多个该特征。在本申请的描述中，“多个”的含义是两个或两个以上，除非另有明确具体的限定。In the description of this application, it should be understood that the terms “first” and “second” are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present application, "a plurality of" means two or more than two, unless otherwise specifically defined.

一种二次电池的制备方法，包括以下步骤：A method for preparing a secondary battery includes the following steps:

S01、将第一正极片与第一隔膜、第一负极片、第一电解液和第一封装外壳进行组装，制备第一电池；所述第一正极片包括第一正极材料和第一正极集流体，所述第一电解液在所述第一电池的充放电循环过程中能够表面钝化所述第一正极集流体；S01. Assemble the first positive electrode sheet with the first separator, the first negative electrode sheet, the first electrolyte and the first packaging shell to prepare a first battery; the first positive electrode sheet includes a first positive electrode material and a first positive electrode set Fluid, the first electrolyte can surface passivate the first positive electrode current collector during the charge and discharge cycle of the first battery;

S02、将所述第一电池进行充放电循环，对所述第一正极片进行表面钝化处理，使得所述第一正极集流体的表面形成钝化层；之后，拆解所述第一电池，取出经过表面钝化处理的第一正极片；S02. Perform a charge and discharge cycle of the first battery, and perform a surface passivation treatment on the first positive electrode sheet, so that a passivation layer is formed on the surface of the first positive electrode current collector; then, the first battery is disassembled , Take out the first positive electrode plate that has undergone surface passivation treatment;

S03、获取第二正极片，所述第二正极片包括：第二正极材料和第二正极集流体，所述第二正极材料与所述第一正极材料相同或不相同，所述第二正极集流体为所述表面经过钝化处理的第一正极集流体；S03. Obtain a second positive electrode sheet, the second positive electrode sheet comprising: a second positive electrode material and a second positive electrode current collector, the second positive electrode material is the same or different from the first positive electrode material, and the second positive electrode The current collector is the first positive electrode current collector whose surface has been passivated;

S04、将所述第二正极片与第二隔膜、第二负极片、第二电解液和第二封装外壳进行组装，所述第二电解液包含双氟磺酰亚胺盐和/或双(三氟甲基磺酰)亚胺盐，制备所述二次电池。S04. Assemble the second positive electrode sheet with the second separator, the second negative electrode sheet, the second electrolyte and the second packaging shell, the second electrolyte containing bisfluorosulfonimide salt and/or bis( Trifluoromethylsulfonyl)imide salt to prepare the secondary battery.

本申请实施例提供的二次电池的方法，将第一正极片与对第一正极集流体具有钝化作用的第一电解液组装形成第一电池，然后对第一电池进行充放电循环，以获得经过表面钝化处理的第一正极片，在此基础上，将其与包含双氟磺酰亚胺盐和/或双(三氟甲基磺酰)亚胺盐的第二电解液重新组装，从而制备获得一种可有效抑制含FSI ^-和TFSI ^-的电解液腐蚀正极集流体的二次电池，其具有良好的安全性能和电化学性能。与现有技术相比，本申请实施例提供的制备方法，步骤简单，成本低，具有良好的重复性和可控性，且抗腐蚀效果明显，促进了基于FSI ^-和TFSI ^-等电解质的二次电池的广泛应用。 In the method of the secondary battery provided by the embodiment of the present application, the first positive electrode sheet is assembled with the first electrolyte that has a passivation effect on the first positive electrode current collector to form the first battery, and then the first battery is charged and discharged to cycle to Obtain the first positive electrode plate with surface passivation treatment, and on this basis, reassemble it with the second electrolyte containing bisfluorosulfonimide salt and/or bis(trifluoromethylsulfonyl)imide salt Therefore, a secondary battery that can effectively inhibit the corrosion of the positive electrode current collector by the electrolyte ^{containing FSI-} and TFSI ^{-is prepared and has good safety performance and electrochemical performance.} Compared with the prior art, the preparation method provided in the present application embodiment, the step of simple, low cost, with good reproducibility and controllability, and anti-corrosive effect is obvious, based on the promotion of the FSI ^- and TFSI ^- like electrolyte di Wide application of secondary batteries.

具体地，所述二次电池指的是一类可通过充电的方式使活性物质激活而继续使用的电池。作为一种实施方式，所述二次电池优选为锂离子电池、钠离子电池、钾离子电池、镁离子电池、钙离子电池或双离子电池。在一些实施例中，所述二次电池为锂离子电池。进一步的，所述二次电池的结构可参考本领域常规电池结构，其主要由正极片、负极片、隔膜、电解液和封装外壳组成。Specifically, the secondary battery refers to a type of battery that can be continuously used by activating the active material by charging. As an embodiment, the secondary battery is preferably a lithium ion battery, a sodium ion battery, a potassium ion battery, a magnesium ion battery, a calcium ion battery or a dual ion battery. In some embodiments, the secondary battery is a lithium ion battery. Further, the structure of the secondary battery can refer to the conventional battery structure in the field, which is mainly composed of a positive electrode sheet, a negative electrode sheet, a separator, an electrolyte, and a packaging shell.

在步骤S01中，所述第一正极片包括第一正极材料和第一正极集流体，所述第一正极材料参考本领域的常规正极材料，可选为商业化正极材料，也可选为其他常用的正极材料。作为一种实施方式，所述第一正极材料包括正极活性材料和导电剂，所述正极活性材料选自钴酸锂、磷酸铁锂、镍钴锰三元材料、锰酸锂和镍锰酸锂中的至少一种，所述导电剂选自活性炭、导电炭黑、石墨烯、碳纳米管、活性碳纤维、石墨烯、介孔碳、碳分子筛、天然石墨和膨胀石墨中的至少一种。作为另一种实施方式，除了正极活性材料和导电剂，所述第一正极材料还包括粘合剂。作为又一种实施方式，将第一正极材料涂覆于待第一正极集流体之后，还包括：烘干和裁片等步骤。所述第一正极集流体的材料可参考本领域的常规材料，例如选为商业化正极集流体。作为一种实施方式，所述第一正极集流体选自包含铝、锡、铜、铁、镍、钛、镁和锌中的至少一种的金属箔材，这类材料价格便宜，导电性好。在一些实施例中，所述第一正极集流体选为铝金属箔材。在另一些实施例中，所述第一正极集流体的厚度为10-1000μm，例如厚10、50、90、110、130、180、190、200、260、299、350、400、440、509、567、601、666、710、750、800、890、900、1000μm。In step S01, the first positive electrode sheet includes a first positive electrode material and a first positive electrode current collector, and the first positive electrode material refers to a conventional positive electrode material in the field, and can be a commercial positive electrode material or other materials. Commonly used cathode materials. As an embodiment, the first positive electrode material includes a positive electrode active material and a conductive agent, and the positive electrode active material is selected from the group consisting of lithium cobaltate, lithium iron phosphate, nickel cobalt manganese ternary material, lithium manganate and lithium nickel manganate. At least one of the conductive agent selected from the group consisting of activated carbon, conductive carbon black, graphene, carbon nanotube, activated carbon fiber, graphene, mesoporous carbon, carbon molecular sieve, natural graphite, and expanded graphite. As another embodiment, in addition to the positive electrode active material and the conductive agent, the first positive electrode material further includes a binder. As yet another embodiment, after coating the first positive electrode material on the first positive electrode current collector, the method further includes the steps of drying and cutting. The material of the first positive electrode current collector can refer to conventional materials in the art, for example, it is selected as a commercial positive electrode current collector. As an embodiment, the first positive electrode current collector is selected from metal foils containing at least one of aluminum, tin, copper, iron, nickel, titanium, magnesium, and zinc. Such materials are inexpensive and have good conductivity. . In some embodiments, the first positive electrode current collector is selected from aluminum metal foil. In other embodiments, the thickness of the first positive electrode current collector is 10-1000 μm, for example, 10, 50, 90, 110, 130, 180, 190, 200, 260, 299, 350, 400, 440, 509. , 567, 601, 666, 710, 750, 800, 890, 900, 1000μm.

所述第一隔膜参考本技术领域的常规隔膜，可选为商业化隔膜，也可选为其他常用的隔膜材料。作为一种实施方式，所述第一隔膜选自玻璃纤维、聚乙烯和聚丙烯中的至少一种。The first diaphragm refers to a conventional diaphragm in the technical field, and may be a commercial diaphragm or other commonly used diaphragm materials. As an embodiment, the first separator is selected from at least one of glass fiber, polyethylene and polypropylene.

所述第一负极参考本技术领域的常规负极，可选为商业化负极，也可采用本领域常规负极。作为一种实施方式，所述第一负极的材料选自锂、钠、钾、石墨、活性炭、导电炭黑、碳纤维、钛酸锂、石墨烯、碳纳米管、硅、铝、锡、铋或锑。在一些实施例中，所述第一负极为金属锂片、金属钠片或金属钾片；在另一些实施例中，所述第一负极为由活性炭、导电炭黑、碳纤维、石墨烯和碳纳米管中的至少一种碳基材料制成的薄片；在又一些实施例中，所述第一负极的材料选为钛酸锂、磷、硫、硅、铝、锡、铋、锑、过渡金属氧化物、过渡金属硫化物和磷化物中的任一种。The first negative electrode refers to a conventional negative electrode in the technical field, and may be a commercial negative electrode, or a conventional negative electrode in the field may also be used. As an embodiment, the material of the first negative electrode is selected from lithium, sodium, potassium, graphite, activated carbon, conductive carbon black, carbon fiber, lithium titanate, graphene, carbon nanotubes, silicon, aluminum, tin, bismuth or antimony. In some embodiments, the first negative electrode is a metallic lithium sheet, a metallic sodium sheet, or a metallic potassium sheet; in other embodiments, the first negative electrode is made of activated carbon, conductive carbon black, carbon fiber, graphene, and carbon. Nanotubes are made of at least one carbon-based material; in other embodiments, the material of the first negative electrode is selected from lithium titanate, phosphorus, sulfur, silicon, aluminum, tin, bismuth, antimony, and Any of metal oxides, transition metal sulfides, and phosphides.

在本申请实施例中，所述第一电解液在所述第一电池的充放电循环中能够表面钝化所述第一正极集流体，使得充放电循环之后所述第一正极集流体的表面形成钝化层，以抑制基于FSI ^-和TFSI ^-等电解质的电解液对第一正极集流体的腐蚀。所述第一电解液为溶解有电解质的溶液，作为一种实施方式，所述第一电解液包含六氟磷酸盐、四氟硼酸盐、六氟砷酸盐、氟化盐、高氯酸盐、二氟草酸硼酸盐和草酸硼酸盐中的至少一种。在一些实施例中，所述六氟磷酸盐优选为六氟磷酸锂、六氟磷酸钠和六氟磷酸钾种的至少一种；在另一些实施例中，所述四氟硼酸盐优选为四氟硼酸锂、四氟硼酸钠和四氟硼酸钾中的至少一种；在又一些实施例中，所述六氟砷酸盐优选为六氟砷酸锂和/或六氟砷酸钠；在再一些实施例中，所述氟化盐优选为氟化锂和/或氟化钠；在其他一些实施例中，所述高氯酸盐优选为高氯酸锂，所述二氟草酸硼酸盐优选为二氟草酸硼酸锂和/或二氟草酸硼酸钠，所述草酸硼酸盐优选为草酸硼酸锂。作为另一种实施方式，所述第一电解液中，用于溶解电解质的溶剂选自酯类有机溶剂、砜类有机溶剂、醚类有机溶剂和腈类有机溶剂中的至少一种。在一些实施例中，所述用于溶解电解质的溶剂优选为碳酸丙烯酯(PC)、碳酸乙烯酯(EC)、碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸甲乙酯(EMC)、氟代碳酸乙烯酯(FEC)、丙酸甲酯(MP)、丙酸乙酯(EP)、乙酸乙酯(EA)、磷酸三甲酯(TMP)、四氢呋喃(THF)、2-甲基四氢呋喃(2MeTHF)、1，3-二氧环戊烷(DOL )、4-甲基-1，3-二氧环戊烷(4MeDOL)、二甲氧甲烷(DMM)、1，2-二甲氧丙烷(DMP)、三乙二醇二甲醚(DG)、二甲基砜(MSM)、环丁砜(TMS)、甲基乙基砜(EMS)，二甲醚(DME)、亚硫酸乙烯酯(ES)、亚硫酸丙烯脂(PS)、亚硫酸二甲脂(DMS)、亚硫酸二乙脂(DES)、乙腈(AN)和己二腈(HN)中中的至少一种。作为又一种实施方式，所述第一电解液中，电解质的浓度为0.1-10mol/L，在保证第一电解液具有良好的离子导电率的同时能够有效钝化正极集流体和正极壳。 In the embodiment of the present application, the first electrolyte can surface passivate the first positive electrode current collector during the charge and discharge cycle of the first battery, so that the surface of the first positive electrode current collector after the charge and discharge cycle A passivation layer is formed to suppress the corrosion of the first positive electrode current collector by the electrolyte ^{based on electrolytes such as FSI-} and TFSI ^-. The first electrolyte is a solution in which electrolytes are dissolved. As an embodiment, the first electrolyte includes hexafluorophosphate, tetrafluoroborate, hexafluoroarsenate, fluoride, and perchloric acid. At least one of salt, difluorooxalic acid borate, and oxalic acid borate. In some embodiments, the hexafluorophosphate is preferably at least one of lithium hexafluorophosphate, sodium hexafluorophosphate and potassium hexafluorophosphate; in other embodiments, the tetrafluoroborate is preferably tetrafluoroborate. At least one of lithium, sodium tetrafluoroborate and potassium tetrafluoroborate; in other embodiments, the hexafluoroarsenate is preferably lithium hexafluoroarsenate and/or sodium hexafluoroarsenate; In embodiments, the fluoride salt is preferably lithium fluoride and/or sodium fluoride; in other embodiments, the perchlorate is preferably lithium perchlorate, and the difluorooxalate borate is preferably Lithium difluorooxalate borate and/or sodium difluorooxalate borate, and the oxalate borate is preferably lithium oxalate borate. As another embodiment, in the first electrolyte, the solvent used to dissolve the electrolyte is selected from at least one of ester organic solvents, sulfone organic solvents, ether organic solvents, and nitrile organic solvents. In some embodiments, the solvent used to dissolve the electrolyte is preferably propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethyl methyl carbonate. (EMC), fluoroethylene carbonate (FEC), methyl propionate (MP), ethyl propionate (EP), ethyl acetate (EA), trimethyl phosphate (TMP), tetrahydrofuran (THF), 2 -Methyltetrahydrofuran (2MeTHF), 1,3-dioxolane (DOL), 4-methyl-1,3-dioxolane (4MeDOL), dimethoxymethane (DMM), 1, 2 -Dimethoxypropane (DMP), triethylene glycol dimethyl ether (DG), dimethyl sulfone (MSM), sulfolane (TMS), methyl ethyl sulfone (EMS), dimethyl ether (DME), sulfide At least one of vinyl sulfate (ES), propylene sulfite (PS), dimethyl sulfite (DMS), diethyl sulfite (DES), acetonitrile (AN), and adiponitrile (HN). As another embodiment, the concentration of the electrolyte in the first electrolyte is 0.1-10 mol/L, which can effectively passivate the positive electrode current collector and the positive electrode shell while ensuring that the first electrolyte has good ionic conductivity.

所述第一封装外壳用于封装形成第一电池，所述第一封装外壳的材料和结构可参考本领域的常规电池封装外壳，本申请实施例对此不作特殊限制。The first packaging shell is used to encapsulate and form a first battery, and the material and structure of the first packaging shell can refer to conventional battery packaging shells in the art, which is not particularly limited in the embodiment of the present application.

将所述第一正极片与第一隔膜、第一负极片、第一电解液和第一封装外壳进行组装的步骤可参考本领域常规操作，本申请实施例对此不作特殊限制。For the steps of assembling the first positive electrode sheet with the first separator, the first negative electrode sheet, the first electrolyte and the first packaging shell, reference may be made to conventional operations in the field, and the embodiment of the present application does not impose special restrictions on this.

在步骤S02中，将所述第一电池进行充放电循环，对所述第一正极片进行表面钝化处理，使得所述第一正极集流体的表面形成钝化层，尤其是在第一正极集流体与第一电解液接触的表面。在进行充放电循环过程中，由于第一电解液中电解质的分解，第一正极集流体的表面逐渐形成一层稳定的钝化层。In step S02, the first battery is subjected to a charge-discharge cycle, and the first positive electrode sheet is subjected to a surface passivation treatment, so that a passivation layer is formed on the surface of the first positive electrode current collector, especially on the first positive electrode. The surface of the current collector in contact with the first electrolyte. During the charge-discharge cycle, due to the decomposition of the electrolyte in the first electrolyte, a stable passivation layer is gradually formed on the surface of the first positive electrode current collector.

作为一种实施方式，将所述第一电池进行充放电循环的步骤中，以1-1000mA/g的电流密度进行充放电循环，有利于在正极集流体和正极壳的表面形成致密稳定的钝化层。在一些实施例中，电流密度为1、15、20、36、49、58、67、79、81、92、100、206、307、410、560、640、730、820、950、1000mA/g。可以理解，将所述第一电池进行充放电循环的步骤中，充放电循环的电压范围由电池的正负极材料决定。作为一种实施方式，所述第一电池的负极为金属锂，将所述第一电池以3-5.4V的电压进行充放电循环，在一些实施例中，所述电压为3-4.8、3-5.0、3-5.2或3-5.4。As an embodiment, in the step of performing the charge and discharge cycle of the first battery, the charge and discharge cycle is performed at a current density of 1-1000 mA/g, which is conducive to the formation of a dense and stable blunt on the surface of the positive electrode current collector and the positive electrode shell.化层。 The layer. In some embodiments, the current density is 1, 15, 20, 36, 49, 58, 67, 79, 81, 92, 100, 206, 307, 410, 560, 640, 730, 820, 950, 1000 mA/g . It can be understood that in the step of subjecting the first battery to a charge-discharge cycle, the voltage range of the charge-discharge cycle is determined by the positive and negative electrode materials of the battery. As an embodiment, the negative electrode of the first battery is metal lithium, and the first battery is charged and discharged at a voltage of 3-5.4V. In some embodiments, the voltage is 3-4.8, 3. -5.0, 3-5.2 or 3-5.4.

对所述第一电池进行充放电循环之后拆解所述第一电池，以获得经过表面钝化处理的第一正极片。所述经过表面钝化处理的第一正极片包括：表面经过钝化处理的第一正极集流体以及所述第一正极材料，可以理解，在进行充放电循环过程中，第一正极材料几乎没有变化。拆解所述第一电池的步骤可参考本领域常规操作，本申请实施例不作具体限定。After the first battery is subjected to a charge-discharge cycle, the first battery is disassembled to obtain a first positive electrode plate with a surface passivation treatment. The first positive electrode sheet subjected to surface passivation treatment includes: a first positive electrode current collector whose surface has been passivated and the first positive electrode material. It can be understood that during the charge and discharge cycle, there is almost no first positive electrode material. Variety. For the steps of disassembling the first battery, reference may be made to conventional operations in the field, and the embodiment of the present application does not specifically limit it.

在步骤S03中，所述第二正极片包括：第二正极材料和第二正极集流体，所述第二正极材料与所述第一正极材料相同或不相同，所述第二正极集流体为所述表面经过钝化处理的第一正极集流体。作为示例一，当第二正极材料与所述第一正极材料相同时，所述第二正极片与所述经过表面钝化处理的第一正极片可为同一个，在后续组装二次电池时，可将所述经过表面钝化处理的第一正极片与第二隔膜、第二负极片、第二电解液和第二封装外壳进行组装，步骤简化，操作方便。作为示例二，当第二正极材料与所述第一正极材不同时，将所述经过表面钝化处理的第一正极片上的第一正极材料与表面经过钝化处理的第一正极集流体分离，然后在表面经过钝化处理的第一正极集流体表面涂覆第二正极材料，之后进行烘干、裁片，获得第二正极片。其中，所述第二正极材料参考本领域的常规正极材料，可选为商业化正极材料，也可选为其他常用的正极材料。In step S03, the second positive electrode sheet includes: a second positive electrode material and a second positive electrode current collector, the second positive electrode material is the same or different from the first positive electrode material, and the second positive electrode current collector is The first positive electrode current collector whose surface has been passivated. As an example one, when the second positive electrode material is the same as the first positive electrode material, the second positive electrode sheet and the first positive electrode sheet subjected to the surface passivation treatment may be the same. When the secondary battery is subsequently assembled , The first positive electrode plate with the surface passivation treatment can be assembled with the second separator, the second negative electrode plate, the second electrolyte and the second packaging shell, the steps are simplified and the operation is convenient. As an example two, when the second positive electrode material is different from the first positive electrode material, the first positive electrode material on the first positive electrode sheet subjected to surface passivation treatment is separated from the first positive electrode current collector whose surface has undergone passivation treatment Then, the second positive electrode material is coated on the surface of the first positive electrode current collector whose surface has been passivated, and then the second positive electrode sheet is obtained by drying and cutting pieces. Wherein, the second positive electrode material refers to conventional positive electrode materials in the field, and can be selected as a commercial positive electrode material or other commonly used positive electrode materials.

在步骤S04中，将所述第二正极片与第二隔膜、第二负极片、第二电解液和第二封装外壳进行组装的步骤可参考本领域常规操作，本申请实施例对此不作特殊限制。In step S04, the step of assembling the second positive electrode sheet with the second separator, the second negative electrode sheet, the second electrolyte and the second packaging shell can refer to the conventional operations in the field, and the embodiment of this application does not make any special considerations for this. limit.

作为一种实施方式，所述第一隔膜与所述第二隔膜相同或不同，且所述第一隔膜和所述第二隔膜的材料各自独立地选自玻璃纤维、聚乙烯和聚丙烯中的至少一种。As an embodiment, the first diaphragm and the second diaphragm are the same or different, and the materials of the first diaphragm and the second diaphragm are each independently selected from the group consisting of glass fiber, polyethylene, and polypropylene. At least one.

作为一种实施方式，所述第一负极和所述第二负极相同或不同，且所述第一负极和所述第二负极的材料各自独立地选自锂、钠、钾、石墨、活性炭、导电炭黑、碳纤维、钛酸锂、石墨烯、碳纳米管、硅、磷、硫、铝、锡、铋、锑、过渡金属氧化物、过渡金属硫化物和磷化物中的任一种。As an embodiment, the first negative electrode and the second negative electrode are the same or different, and the materials of the first negative electrode and the second negative electrode are each independently selected from lithium, sodium, potassium, graphite, activated carbon, Conductive carbon black, carbon fiber, lithium titanate, graphene, carbon nanotube, silicon, phosphorus, sulfur, aluminum, tin, bismuth, antimony, transition metal oxide, transition metal sulfide, and phosphide.

可以理解，当所述第一隔膜与所述第二隔膜相同，所述第一负极和所述第二负极相同，且所述第二正极片与所述经过表面钝化处理的第一正极片为同一个时，所述第一电池与所述二次电池的主要区别为电解液的不同，在组装二次电极时，将所述第一电解液替换为所述第二电解液即可，操作简便，可大大缩短工艺周期，节约成本。It can be understood that when the first separator is the same as the second separator, the first negative electrode and the second negative electrode are the same, and the second positive electrode plate is the same as the first positive electrode plate that has undergone surface passivation. When they are the same, the main difference between the first battery and the secondary battery is the difference in electrolyte. When assembling the secondary electrode, the first electrolyte can be replaced with the second electrolyte. The operation is simple, which can greatly shorten the process cycle and save costs.

所述第二电解液含双氟磺酰亚胺盐和/或双(三氟甲基磺酰)亚胺盐，作为所述二次电池的电解质。作为一种实施方式，所述双氟磺酰亚胺盐选自双氟磺酰亚胺锂、双氟磺酰亚胺钠、双氟磺酰亚胺钾、双氟磺酰亚胺镁和双氟磺酰亚胺钙。作为另一种实施方式，所述双(三氟甲基磺酰)亚胺盐选自双(三氟甲基磺酰)亚胺锂、双(三氟甲基磺酰)亚胺钠、双(三氟甲基磺酰)亚胺钾、双(三氟甲基磺酰)亚胺镁和双(三氟甲基磺酰)亚胺钙中的至少一种。进一步的，所述第一电解液还含有用于溶解双氟磺酰亚胺盐和/或双(三氟甲基磺酰)亚胺盐的溶剂。在一些实施例中，所述溶剂优选为酯类有机溶剂、砜类有机溶剂、醚类有机溶剂何腈类有机溶剂中的至少一种，包括但不限于碳酸丙烯酯(PC)、碳酸乙烯酯(EC)、碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸甲乙酯(EMC)、氟代碳酸乙烯酯(FEC)、丙酸甲酯(MP)、丙酸乙酯(EP)、乙酸乙酯(EA)、磷酸三甲酯(TMP)、四氢呋喃(THF)、2-甲基四氢呋喃(2MeTHF)、1，3-二氧环戊烷(DOL)、4-甲基-1，3-二氧环戊烷(4MeDOL)、二甲氧甲烷(DMM)、1，2-二甲氧丙烷(DMP)、三乙二醇二甲醚(DG)、二甲基砜(MSM)、环丁砜(TMS)、甲基乙基砜(EMS)，二甲醚(DME)、亚硫酸乙烯酯(ES)、亚硫酸丙烯脂(PS)、亚硫酸二甲脂(DMS)、亚硫酸二乙脂(DES)、乙腈(AN)和己二腈(HN)中的至少一种。在另一些实施例中，所述第二电解液中，电解质的浓度为0.1-10mol/L。The second electrolyte contains a bisfluorosulfonimide salt and/or a bis(trifluoromethylsulfonyl)imide salt as the electrolyte of the secondary battery. As an embodiment, the bisfluorosulfonimide salt is selected from lithium bisfluorosulfonimide, sodium bisfluorosulfonimide, potassium bisfluorosulfonimide, magnesium bisfluorosulfonimide, and bisfluorosulfonimide. Calcium fluorosulfonimide. As another embodiment, the bis(trifluoromethylsulfonyl)imide salt is selected from lithium bis(trifluoromethanesulfonyl)imide, sodium bis(trifluoromethanesulfonyl)imide, bis(trifluoromethylsulfonyl)imide At least one of potassium (trifluoromethylsulfonyl)imide, magnesium bis(trifluoromethylsulfonyl)imide, and calcium bis(trifluoromethylsulfonyl)imide. Further, the first electrolyte solution further contains a solvent for dissolving the bisfluorosulfonimide salt and/or bis(trifluoromethylsulfonyl)imide salt. In some embodiments, the solvent is preferably at least one of ester organic solvents, sulfone organic solvents, ether organic solvents and nitrile organic solvents, including but not limited to propylene carbonate (PC) and ethylene carbonate. (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), fluoroethylene carbonate (FEC), methyl propionate (MP), ethyl propionate ( EP), ethyl acetate (EA), trimethyl phosphate (TMP), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2MeTHF), 1,3-dioxolane (DOL), 4-methyl- 1,3-Dioxolane (4MeDOL), Dimethoxymethane (DMM), 1,2-Dimethoxypropane (DMP), Triethylene glycol dimethyl ether (DG), Dimethyl sulfone (MSM) ), sulfolane (TMS), methyl ethyl sulfone (EMS), dimethyl ether (DME), vinyl sulfite (ES), propylene sulfite (PS), dimethyl sulfite (DMS), sulfurous acid At least one of diethyl ester (DES), acetonitrile (AN) and adiponitrile (HN). In other embodiments, the concentration of the electrolyte in the second electrolyte is 0.1-10 mol/L.

不同于PF ₆ ^-类型电解质，FSI ^-和TFSI ^-等电解质在电池循环过程中不能有效钝化正极集流体，例如金属铝箔等，而且，由于FSI ^-和TFSI ^-的强酸性，以双氟磺酰亚胺盐和/或双(三氟甲基磺酰)亚胺盐为电解质的二次电池中，其正极集流体和正极壳的腐蚀问题较为严重。本申请实施例在组装二次电池之前采用电池循环的方法对正极集流体进行表面钝化处理，可有效抑制正极集流体腐蚀，解决了现有二次电池中基于FSI ^-和TFSI ^-等电解质的电解液存在的对正极集流体以及正极壳的腐蚀问题，步骤简单，成本低，具有良好的重复性和可控性，且抗腐蚀效果明显，促进了基于FSI ^-和TFSI ^-等电解质的二次电池的广泛应用。 Unlike PF ₆ ^- type electrolyte, FSI ^- and TFSI ^- and the like can not be effectively passivated the electrolyte in the positive current collector during cell cycling, such as metal foil, etc., and, since the FSI ^- and TFSI ^- strongly acidic, double fluorosulfonyl In secondary batteries in which imine salt and/or bis(trifluoromethylsulfonyl)imide salt are electrolytes, the problem of corrosion of the positive electrode current collector and the positive electrode shell is more serious. In the embodiment of the application, the positive electrode current collector is surface passivated by the battery cycle method before assembling the secondary battery, which can effectively inhibit the corrosion of the positive electrode current collector and solve the problem of electrolytes ^{based on FSI-} and TFSI ^{-in existing secondary batteries.} corrosion of the positive electrode current collector and a positive electrode of electrolytic solution exists, step simple, low cost, with good reproducibility and controllability, and anti-corrosive effect is obvious, based on the promotion of the FSI ^- and TFSI ^- like electrolyte secondary Wide application of batteries.

在本申请实施例中，所述二次电池可为扣式电池，也可为卷绕式电池。在在一些实施方式中，所述二次电池为扣式电池，扣式电池的封装外壳主要由正极壳和负极壳组装形成，且正极壳常规为不锈钢合金材质。与正极集流体一样，正极壳在电池循环过程中也容易被含FSI ^-和TFSI ^-的电解液腐蚀，一定程度上影响到二次电池的安全性能和电化学性能。 In the embodiment of the present application, the secondary battery may be a button battery or a wound battery. In some embodiments, the secondary battery is a button battery, and the packaging shell of the button battery is mainly formed by assembling a positive electrode case and a negative electrode case, and the positive electrode case is conventionally made of a stainless steel alloy. Like the positive electrode current collector, the positive electrode shell is also easily ^{corroded by the electrolyte containing FSI-} and TFSI ^- during the battery cycle, which affects the safety performance and electrochemical performance of the secondary battery to a certain extent.

作为一种实施方式，所述二次电池为扣式电池，所述第二封装外壳包括第二正极壳，且所述第二正极壳的表面形成有钝化层。如此，以有效抑制含FSI ^-和TFSI ^-的电解液腐蚀正极壳的问题。进一步的，所述第一电池为扣式电池，所述第一封装外壳包括第一正极壳，将所述第一电池进行充放电循环时所述第一正极壳的表面形成钝化层，且所述第二正极壳为表面形成有钝化层的所述第一正极壳。利用电池循环的方法对第一正极集流体和第一正极壳同时进行表面钝化处理，然后采用经过表面钝化处理的第一正极片和第一正极壳与基于FSI ^-和TFSI ^-等电解质的电解液及其他部分进行组装二次电池，大大简化了二次电池的制备工艺，缩短了工艺周期，有效降低了成本。在一些实施例中，所述第一正极壳选自铝、锡、铜、铁、镍、钛、镁和锌中的至少一种金属形成的不锈钢合金，其具有良好的导电性和稳定性，价格便宜，性能稳定。 As an embodiment, the secondary battery is a button battery, the second packaging shell includes a second positive electrode shell, and a passivation layer is formed on the surface of the second positive electrode shell. In this way, the problem of corrosion of the positive electrode case by the electrolyte ^{containing FSI-} and TFSI ^{-can be effectively suppressed.} Further, the first battery is a button battery, the first packaging casing includes a first positive electrode shell, and a passivation layer is formed on the surface of the first positive electrode shell when the first battery is subjected to a charge-discharge cycle, and The second positive electrode case is the first positive electrode case on which a passivation layer is formed. The first positive electrode current collector and the first positive electrode shell are simultaneously subjected to surface passivation treatment using the method of battery cycling, and then the first positive electrode sheet and the first positive electrode shell that have undergone the surface passivation treatment and the electrolyte ^{based on FSI-} and TFSI ^{-are used.} The electrolyte and other parts are used to assemble the secondary battery, which greatly simplifies the preparation process of the secondary battery, shortens the process cycle, and effectively reduces the cost. In some embodiments, the first positive electrode shell is a stainless steel alloy formed of at least one metal selected from aluminum, tin, copper, iron, nickel, titanium, magnesium, and zinc, which has good conductivity and stability, The price is cheap and the performance is stable.

相应的，由上述制备方法制得的二次电池。Correspondingly, the secondary battery produced by the above-mentioned production method.

本申请实施例提供的二次电池，由上述制备方法制得，具有良好的安全性能和电化学性能。The secondary battery provided in the examples of the application is prepared by the above-mentioned preparation method and has good safety performance and electrochemical performance.

经过实验测试，由上述制备方法制得的二次电池，在循环500次后，其容量保持率高达83％，库伦效率高达94％，具有良好的循环稳定性能和倍率性能。After experimental tests, the secondary battery prepared by the above preparation method has a capacity retention rate of up to 83% and a coulombic efficiency of 94% after 500 cycles, and has good cycle stability and rate performance.

为了使本申请要解决的技术问题、技术方案及有益效果更加清楚明白，以下结合具体实施例，对本申请进行进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本申请，并不用于限定本申请。In order to make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the application will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described here are only used to explain the application, and not used to limit the application.

实施例1：Example 1:

本实施例提供了一种锂离子电池，其具体制备过程包括以下步骤：This embodiment provides a lithium ion battery, and its specific preparation process includes the following steps:

1、制备第一电池1. Prepare the first battery

1)将钴酸锂、聚偏氟乙烯(PVDF)和导电炭黑按8∶1∶1的质量比例混合均匀，同时加入一定量的甲基吡咯烷酮(NMP)进行研磨均匀，获得第一正极材料；然后，将第一正极材料涂覆在铝箔上，烘干，切片，制备成第一正极片。1) Mix lithium cobaltate, polyvinylidene fluoride (PVDF) and conductive carbon black in a mass ratio of 8:1:1, and add a certain amount of methylpyrrolidone (NMP) to grind uniformly to obtain the first positive electrode material ; Then, the first positive electrode material is coated on the aluminum foil, dried, sliced, and prepared into a first positive electrode sheet.

2)称取六氟磷酸锂，加入到碳酸乙烯酯和碳酸二甲酯的混合溶剂(v/v＝1∶1) 中，制备成浓度为1M的六氟磷酸锂溶液，作为第一电解液。2) Weigh lithium hexafluorophosphate and add it to a mixed solvent of ethylene carbonate and dimethyl carbonate (v/v=1:1) to prepare a lithium hexafluorophosphate solution with a concentration of 1M as the first electrolyte.

3)在手套箱中，将第一负极片4、金属锂片、第一隔膜3、第一正极片2依次紧密堆叠，置于第一正极壳1上，滴加第一电解液，扣上第一负极壳5，获得第一电池，其主体部分的剖面结构如图1所示。3) In the glove box, stack the first negative electrode sheet 4, the metal lithium sheet, the first separator 3, and the first positive electrode sheet 2 closely in sequence, and place them on the first positive electrode shell 1, drop the first electrolyte solution, and buckle it. The first negative electrode shell 5 obtains the first battery, and the cross-sectional structure of the main body part is shown in FIG. 1.

4)以100mA/g的电流对半电池进行充放电循环，在3-4.8V的电压范围内循环50圈后拆解半电池，取出第一正极片2和第一正极壳1。4) The half-cell is charged and discharged at a current of 100mA/g, and the half-cell is disassembled after 50 cycles in the voltage range of 3-4.8V, and the first positive electrode sheet 2 and the first positive electrode case 1 are taken out.

2、组装锂离子电池二次电池2. Assemble lithium ion battery secondary battery

1)将天然石墨、聚偏氟乙烯(PVDF)、导电碳黑按8∶1∶1的质量比例混合均匀，制备成第二负极片。1) Natural graphite, polyvinylidene fluoride (PVDF), and conductive carbon black are uniformly mixed in a mass ratio of 8:1:1 to prepare a second negative electrode sheet.

2)称取双氟磺酰亚胺锂，加入到碳酸乙烯酯和碳酸二甲酯的混合溶剂(v/v＝1∶1)中，配置成浓度为1M的双氟磺酰亚胺锂溶液，作为第二电解液。2) Weigh out lithium bisfluorosulfonimide and add it to the mixed solvent of ethylene carbonate and dimethyl carbonate (v/v=1:1) to prepare a solution of lithium bisfluorosulfonimide with a concentration of 1M , As the second electrolyte.

3)将步骤1中半电池拆解后得到的第一正极片2和第一正极壳1，以第一正极片2作为第二正极片7，以第一正极壳1作为第二正极壳6，然后将第二正极片7与第二隔膜8、第二负极片9依次紧密堆叠，置于第二正极壳6上，滴加第二电解液使隔膜完全浸润，扣上第二负极壳10，最后通过封装完成锂离子电池的组装，其主体部分的剖面结构如图2所示。3) The first positive electrode sheet 2 and the first positive electrode case 1 obtained after disassembling the half-cell in step 1, the first positive electrode sheet 2 is used as the second positive electrode sheet 7, and the first positive electrode case 1 is used as the second positive electrode case 6. Then, the second positive electrode sheet 7 is closely stacked with the second separator 8 and the second negative electrode sheet 9 in turn, placed on the second positive electrode shell 6, and the second electrolyte solution is dripped to make the separator completely wet, and the second negative electrode shell 10 is buckled. Finally, the assembly of the lithium-ion battery is completed by packaging, and the cross-sectional structure of the main body is shown in Figure 2.

实施例2：Example 2:

本实施例提供了一种基于锂的双离子电池，其具体制备过程包括以下步骤：This embodiment provides a lithium-based dual-ion battery, and its specific preparation process includes the following steps:

1、制备第一电池1. Prepare the first battery

1)将膨胀石墨、聚偏氟乙烯(PVDF)和导电炭黑按8∶1∶1的质量比例混合均匀，研磨，然后涂覆到铝箔片上，烘干、切片，制备成正极片。1) Expanded graphite, polyvinylidene fluoride (PVDF) and conductive carbon black are uniformly mixed in a mass ratio of 8:1:1, ground, and then coated on an aluminum foil sheet, dried, and sliced to prepare a positive electrode sheet.

2)称取二氟草酸硼酸锂，加入到碳酸乙烯酯和碳酸二甲酯的混合溶剂(v/v＝1∶1)中，制备成浓度为1M的二氟草酸硼酸锂电解液。2) Weigh out lithium difluorooxalate borate and add it to a mixed solvent (v/v=1:1) of ethylene carbonate and dimethyl carbonate to prepare a lithium difluorooxalate borate electrolyte with a concentration of 1M.

3)在手套箱中，将金属锂、隔膜、正极片依次紧密堆叠，组装正极壳和负极壳，滴加电解液，进行半电池的组装，获得第一电池。3) In the glove box, the metal lithium, the separator, and the positive electrode sheet are closely stacked in sequence, the positive electrode shell and the negative electrode shell are assembled, the electrolyte is added dropwise, and the half-cell assembly is performed to obtain the first battery.

4)以100mA/g的电流对第一电池进行充放电循环，在3-5V的电压范围内循环50圈后拆解第一电池，取出经过表面钝化处理的正极片和正极壳。4) Charge and discharge the first battery with a current of 100mA/g, and disassemble the first battery after 50 cycles in the voltage range of 3-5V, and take out the positive electrode sheet and the positive electrode case that have undergone surface passivation.

2、组装基于锂的双离子电池二次电池2. Assemble lithium-based dual-ion battery secondary batteries

1)将50μm厚度的铝箔裁切成负极片；1) Cut the aluminum foil with a thickness of 50μm into a negative electrode sheet;

2)在手套箱中称取双氟磺酰亚胺锂，加入到碳酸乙烯酯和碳酸二甲酯的混合溶剂(v/v＝1∶1)中，配置成浓度为5M的双氟磺酰亚胺锂电解液。2) Weigh bisfluorosulfonimide lithium in the glove box, add it to the mixed solvent of ethylene carbonate and dimethyl carbonate (v/v=1:1), and configure it to a concentration of 5M bisfluorosulfonyl Lithium imide electrolyte.

3)将步骤1中第一电池拆解后得到的正极片和正极壳与隔膜、负极片依次紧密堆叠，组装正极壳和负极壳，滴加电解液使隔膜完全浸润，最后通过封装完成基于锂的双离子电池的组装。3) The positive electrode sheet and the positive electrode shell, the separator, and the negative electrode sheet obtained after disassembling the first battery in step 1 are closely stacked in sequence, the positive electrode shell and the negative electrode shell are assembled, the electrolyte is dripped to make the separator completely infiltrated, and finally the lithium-based is completed by packaging. The assembly of the dual-ion battery.

实施例3：Example 3:

本实施例提供了一种基于钾的双离子电池，其具体制备过程包括以下步骤：This embodiment provides a potassium-based dual-ion battery, and its specific preparation process includes the following steps:

1、制备第一电池1. Prepare the first battery

2)称取六氟磷酸钾，加入到碳酸乙烯酯和碳酸二甲酯的混合溶剂(v/v＝1∶1)中，制备成浓度为1M的六氟磷酸钾电解液。2) Weigh potassium hexafluorophosphate and add it to a mixed solvent (v/v=1:1) of ethylene carbonate and dimethyl carbonate to prepare a potassium hexafluorophosphate electrolyte with a concentration of 1M.

3)在手套箱中，将金属钾、隔膜、正极片依次紧密堆叠，滴加电解液，进行半电池的组装，获得第一电池。3) In the glove box, the metal potassium, the separator, and the positive electrode sheet are closely stacked in sequence, and the electrolyte is added dropwise to assemble the half-cell to obtain the first battery.

4)以100mA/g的电流对第一电池进行充放电循环，在3-5V的电压范围内循环50圈后拆解半电池，取出经过表面钝化处理的正极片和正极壳。4) Charge and discharge the first battery with a current of 100mA/g, disassemble the half-cell after 50 cycles in the voltage range of 3-5V, and take out the positive electrode sheet and the positive electrode shell that have undergone surface passivation.

1)将100μm厚度的锡箔裁切成负极片；1) Cut the tin foil with a thickness of 100μm into a negative electrode sheet;

2)在手套箱中称取双氟磺酰亚胺钾，加入到碳酸乙烯酯和碳酸二甲酯的混合溶剂(v/v＝1∶1)中，配置成浓度为5M的双氟磺酰亚胺钾电解液。2) Weigh bisfluorosulfonimide potassium in the glove box, add it to the mixed solvent of ethylene carbonate and dimethyl carbonate (v/v=1:1), and configure it to a concentration of 5M bisfluorosulfonyl Potassium imide electrolyte.

3)将步骤1中第一电池拆解后得到的正极片和正极壳与隔膜、负极片依次紧密堆叠，滴加电解液使隔膜完全浸润，最后通过封装完成基于钾的双离子电池的组装。3) The positive electrode sheet and the positive electrode shell obtained after the disassembly of the first battery in step 1 are closely stacked with the separator and the negative electrode sheet in sequence, the electrolyte is dripped to completely infiltrate the separator, and finally the assembly of the potassium-based dual-ion battery is completed by packaging.

实施例4-15与实施例1的区别在于：制备第一电池的步骤4)中采用不同的充放电循环次数和充放电电流密度，实施例16省略制备第一电池的步骤4)，其他地方与实施例1基本相同。其中，实施例1和实施例4-16的制备第一电池的步骤4)中的充放电循环次数及其电流密度如表1所示。The difference between Examples 4-15 and Example 1 is that different charge-discharge cycles and charge-discharge current densities are used in step 4) of preparing the first battery. Example 16 omits step 4) of preparing the first battery. Other places It is basically the same as Example 1. Among them, the number of charge and discharge cycles and the current density in step 4) of preparing the first battery in Example 1 and Examples 4-16 are shown in Table 1.

将实施例1和实施例4-16制得的电池进行电化学性能的测试，测试结果如表1所示。The batteries prepared in Example 1 and Examples 4-16 were tested for electrochemical performance, and the test results are shown in Table 1.

表1Table 1

[Table 1][Table 1]

实施例17-28与实施例2的区别在于：制备第一电池的步骤4)中采用不同的充放电循环次数和充放电电流密度，实施例29省略制备第一电池的步骤4)，其他地方与实施例1基本相同。其中，实施例2和实施例17-28的制备第一电池的步骤4)中的充放电循环次数及其电流密度如表2所示。The difference between Examples 17-28 and Example 2 is that different charge-discharge cycles and charge-discharge current densities are used in step 4) of preparing the first battery. Example 29 omits step 4) of preparing the first battery. Other places It is basically the same as Example 1. Among them, the number of charge and discharge cycles and the current density in step 4) of preparing the first battery in Example 2 and Examples 17-28 are shown in Table 2.

将实施例2和实施例17-29制得的电池进行电化学性能的测试，测试结果如表2所示。The batteries prepared in Example 2 and Examples 17-29 were tested for electrochemical performance, and the test results are shown in Table 2.

表2Table 2

[Table 2][Table 2]

实施例30-42与实施例3的区别在于：制备第一电池的步骤4)中采用不同的充放电循环次数和充放电电流密度，实施例42省略制备第一电池的步骤4)，其他地方与实施例1基本相同。其中，实施例3和实施例30-42的制备第一电池的步骤4)中的充放电循环次数及其电流密度如表3所示。The difference between Examples 30-42 and Example 3 is that different charge-discharge cycles and charge-discharge current densities are used in step 4) of preparing the first battery. Example 42 omits step 4) of preparing the first battery. Other places It is basically the same as Example 1. Among them, the number of charge and discharge cycles and the current density in step 4) of preparing the first battery in Example 3 and Examples 30-42 are shown in Table 3.

将实施例3和实施例30-42制得的电池进行电化学性能的测试，测试结果如表3所示。The batteries prepared in Example 3 and Examples 30-42 were tested for electrochemical performance, and the test results are shown in Table 3.

表3table 3

[Table 3][Table 3]

实施例43：Example 43:

本实施例提供了一种Li-石墨双离子电池，与实施例2的区别在于：制备第一电池的步骤2)中采用六氟磷酸锂作为钝化电解质；组装二次电池的步骤2)中配置浓度为9M的双氟磺酰亚胺锂电解液。其余地方与实施例2基本相同，此处不再一一赘述。This embodiment provides a Li-graphite dual-ion battery. The difference from embodiment 2 is that lithium hexafluorophosphate is used as the passivation electrolyte in step 2) of preparing the first battery; the configuration concentration in step 2) of assembling the secondary battery is 9M lithium bisfluorosulfonimide electrolyte. The other parts are basically the same as in Embodiment 2, and will not be repeated here.

图3为制备第一电池的步骤4)中的充放电曲线，显示，由于六氟磷酸锂的钝化作用，该第一电池能够有效的进行充放电，并表现出较高的容量和较好的循环稳定性。Figure 3 is the charge and discharge curve in step 4) of preparing the first battery, showing that due to the passivation effect of lithium hexafluorophosphate, the first battery can effectively charge and discharge, and exhibits higher capacity and better cycle stability Sex.

将本实施例制得的Li-石墨双离子电池进行充放电循环性能测试，在3-5V的电压范围内、以400mA/g进行充放电的循环性能测试结果如图4所示，采用经过钝化后的正极片以及正极壳组装得到的二次电池，表现出较好的循环稳定性。The Li-graphite dual-ion battery prepared in this example was subjected to a charge-discharge cycle performance test. The charge-discharge cycle performance test results of 400mA/g in a voltage range of 3-5V are shown in Figure 4, using a blunt The secondary battery assembled from the positive electrode sheet and the positive electrode shell after chemicalization exhibits good cycle stability.

实施例44：Example 44:

本实施例提供了一种Li-石墨双离子电池，与实施例2的区别在于：组装二次电池的步骤2)中配置浓度为7M的双氟磺酰亚胺锂电解液。其余地方与实施例2基本相同，此处不再一一赘述。This embodiment provides a Li-graphite dual-ion battery. The difference from the second embodiment is that in step 2) of assembling the secondary battery, a lithium bisfluorosulfonimide electrolyte with a concentration of 7M is configured. The other parts are basically the same as in Embodiment 2, and will not be repeated here.

将本实施例制得的Li-石墨双离子电池进行充放电循环性能测试，在3-5V的电压范围内、以200mA/g进行充放电的循环性能测试结果如图5所示，显示经过LiDFOB钝化后的正极片以及正极壳组装形成的二次电池，同样表现出较好的循环稳定性。The Li-graphite dual-ion battery prepared in this example was subjected to a charge-discharge cycle performance test. The cycle performance test results of the charge-discharge cycle performance at 200mA/g within a voltage range of 3-5V are shown in Fig. 5, showing that the LiDFOB The secondary battery formed by the passivation of the positive electrode sheet and the positive electrode shell also shows better cycle stability.

对比例1：Comparative example 1:

2)称取双氟磺酰亚胺锂，加入到碳酸乙烯酯和碳酸二甲酯的混合溶剂(v/v＝1∶1)中，制备成浓度为9M的双氟磺酰亚胺锂电解液。2) Weigh bisfluorosulfonimide lithium and add it to the mixed solvent of ethylene carbonate and dimethyl carbonate (v/v=1:1) to prepare a 9M bisfluorosulfonimide lithium electrolysis liquid.

3)在手套箱中，将金属锂、隔膜、正极片依次紧密堆叠，滴加电解液，进行半电池的组装，获得第一电池。3) In the glove box, the metal lithium, the separator, and the positive electrode sheet are closely stacked in sequence, and the electrolyte is added dropwise to assemble the half-cell to obtain the first battery.

以电流密度为200mA/g、电压为3-5V进行充放电循环，并监测其循环性能，结果如图6所示，其电池电压难以达到5V。为了证实双氟磺酰亚胺锂对正极铝箔的腐蚀，通过组装LiIIAl半电池，在5V电压下保持10小时后，拆解半电池，取出正极铝箔，进行电镜扫描，图7为不同倍数下的电镜扫描图像，显示铝箔表面已经发生了明显的腐蚀。The current density is 200mA/g and the voltage is 3-5V for charging and discharging cycles, and the cycle performance is monitored. As shown in Figure 6, the battery voltage is difficult to reach 5V. In order to confirm the corrosion of lithium bisfluorosulfonimide on the positive aluminum foil, the LiIIAl half-cell was assembled and kept at 5V for 10 hours. The half-cell was disassembled, the positive aluminum foil was taken out, and the electron microscope was scanned. Figure 7 shows the results under different magnifications. Scanning the image with an electron microscope shows that the surface of the aluminum foil has undergone significant corrosion.

对比例2：Comparative example 2:

以电流密度为200mA/g、电压为3-5V进行充放电循环，并监测其充放电过程绘制充放电曲线，结果如图8所示，该第一电池能够进行有效的充放电，且具有较好的循环稳定性。为了证实二氟草酸硼酸锂对正极铝箔的钝化作用，通过组装LiIIAl半电池，在5V电压下保持电循环10小时后，拆解半电池，取出正极铝箔，进行电镜扫描，图9为铝箔表面的电镜扫描图像，显示铝箔表面完整，没有发生明显的腐蚀现象。The charge-discharge cycle was performed with a current density of 200mA/g and a voltage of 3-5V, and the charge-discharge process was monitored to draw a charge-discharge curve. The result is shown in Figure 8. Good cycle stability. In order to verify the passivation effect of lithium difluorooxalate on the aluminum foil of the positive electrode, the LiIIAl half-cell was assembled, and the half-cell was kept under 5V voltage for 10 hours. The half-cell was disassembled, the positive aluminum foil was taken out, and the electron microscope was scanned. Figure 9 shows the surface of the aluminum foil. The scanning image of the electron microscope showed that the surface of the aluminum foil was intact and there was no obvious corrosion phenomenon.

以上仅为本申请的可选实施例而已，并不用于限制本申请。对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的权利要求范围之内。The above are only optional embodiments of the application, and are not used to limit the application. For those skilled in the art, this application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the scope of the claims of this application.

Claims

A method for preparing a secondary battery is characterized in that it comprises the following steps:

Assemble the first positive electrode sheet with the first separator, the first negative electrode sheet, the first electrolyte and the first packaging shell to prepare a first battery; the first positive electrode sheet includes a first positive electrode material and a first positive electrode current collector, The first electrolyte can surface passivate the first positive electrode current collector during the charge and discharge cycle of the first battery;

The first battery is subjected to a charge-discharge cycle, and the first positive electrode sheet is subjected to surface passivation treatment, so that a passivation layer is formed on the surface of the first positive electrode current collector; then, the first battery is disassembled and taken out The first positive electrode plate with surface passivation treatment;

Obtain a second positive electrode sheet, the second positive electrode sheet comprising: a second positive electrode material and a second positive electrode current collector, the second positive electrode material is the same or different from the first positive electrode material, and the second positive electrode current collector Is the first positive electrode current collector whose surface has been passivated;

Assemble the second positive electrode sheet with the second separator, the second negative electrode sheet, the second electrolyte and the second packaging shell. The second electrolyte contains bisfluorosulfonimide salt and/or bis(trifluoro Methylsulfonyl)imide salt to prepare the secondary battery.

The preparation method according to claim 1, wherein in the step of subjecting the first battery to a charge and discharge cycle, the charge and discharge cycle is performed at a current density of 1-1000 mA/g.

The preparation method according to claim 1, wherein in the step of subjecting the first battery to a charge-discharge cycle, the negative electrode material of the first battery is metallic lithium, and the voltage of the charge-discharge cycle is 3- 5.4V.

The preparation method according to claim 1, wherein in the step of subjecting the first battery to charge and discharge cycles, the number of charge and discharge cycles is 1-1000.

The manufacturing method according to claim 1, wherein the second packaging shell comprises a second positive electrode shell, and a passivation layer is formed on the surface of the second positive electrode shell.

The preparation method according to claim 3, wherein the first packaging shell comprises a first positive electrode shell, and a passivation layer is formed on the surface of the first positive electrode shell when the first battery is subjected to a charge-discharge cycle. And the second positive electrode case is the first positive electrode case with a passivation layer formed on the surface.

The preparation method according to claim 6, wherein the first positive electrode case is a stainless steel alloy formed by at least one of aluminum, tin, copper, iron, nickel, titanium, magnesium, and zinc.

The preparation method according to claim 1, wherein the first electrolyte contains hexafluorophosphate, tetrafluoroborate, hexafluoroarsenate, fluoride salt, perchlorate, difluorooxalic acid At least one of borate and oxalate borate.

The preparation method according to claim 1, wherein the first positive electrode current collector is selected from metal foils containing at least one of aluminum, tin, copper, iron, nickel, titanium, magnesium, and zinc.

The preparation method according to claim 1, wherein the first diaphragm and the second diaphragm are the same or different, and the materials of the first diaphragm and the second diaphragm are each independently selected from glass fiber , At least one of polyethylene and polypropylene.

The preparation method according to claim 1, wherein the first negative electrode and the second negative electrode are the same or different, and the materials of the first negative electrode and the second negative electrode are each independently selected from lithium, Sodium, potassium, graphite, activated carbon, conductive carbon black, carbon fiber, lithium titanate, graphene, carbon nanotubes, silicon, phosphorus, sulfur, aluminum, tin, bismuth, antimony, transition metal oxides, transition metal chalcogenides and Any of phosphides.

The preparation method according to claim 1, wherein the bisfluorosulfonimide salt is selected from the group consisting of lithium bisfluorosulfonimide, sodium bisfluorosulfonimide, potassium bisfluorosulfonimide, and bisfluorosulfonimide. At least one of fluorosulfonimide magnesium and bisfluorosulfonimide calcium.

The preparation method according to claim 1, wherein the bis(trifluoromethylsulfonyl)imide salt is selected from lithium bis(trifluoromethanesulfonyl)imide, bis(trifluoromethanesulfonyl)imide At least one of sodium bis(trifluoromethylsulfonyl)imide, potassium bis(trifluoromethanesulfonyl)imide, magnesium bis(trifluoromethanesulfonyl)imide, and calcium bis(trifluoromethanesulfonyl)imide.

The preparation method according to claim 1, wherein the solvent of the second electrolyte is at least one of an ester organic solvent, a sulfone organic solvent, an ether organic solvent, and a nitrile organic solvent.

A secondary battery produced by the production method according to any one of claims 1 to 14.