CN115939308A - Lithium-supplement positive pole piece, preparation method thereof and lithium ion battery - Google Patents
Lithium-supplement positive pole piece, preparation method thereof and lithium ion battery Download PDFInfo
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Abstract
Description
技术领域Technical Field
本发明属于锂离子电池技术领域,涉及一种补锂正极极片及其制备方法与锂离子电池。The invention belongs to the technical field of lithium ion batteries and relates to a lithium-supplemented positive electrode plate and a preparation method thereof and a lithium ion battery.
背景技术Background Art
为了满足电动汽车和大规模储能的需求,下一代动力电池需要更高的能量密度,而下一代储能电池具有更高的循环寿命,目前能同时提升电池能量密度和循环寿命的技术就是补锂技术。In order to meet the needs of electric vehicles and large-scale energy storage, the next generation of power batteries need higher energy density, while the next generation of energy storage batteries have a higher cycle life. The current technology that can simultaneously improve battery energy density and cycle life is lithium supplementation technology.
补锂技术主要包括负极电化学法、负极化学法和正极预锂化法。Lithium replenishment technologies mainly include negative electrode electrochemical method, negative electrode chemical method and positive electrode pre-lithiation method.
负极电化学法主要是在电池装配前,将负极与锂源、电解液组成一个电池,并对负极进行充电,预先在负极存储一定量的锂离子,然后将该负极与对应正极材料一起组装成全电池。该方法涉及电池拆卸后再组装问题,使得整个操作复杂、工艺成本高、不适宜大批量生产。The negative electrode electrochemical method mainly involves assembling a battery with a negative electrode, a lithium source, and an electrolyte before assembling the battery, charging the negative electrode, storing a certain amount of lithium ions in the negative electrode in advance, and then assembling the negative electrode with the corresponding positive electrode material into a full battery. This method involves the problem of disassembling the battery and then assembling it, which makes the entire operation complicated, the process cost high, and is not suitable for mass production.
目前,研究较多的方法是负极化学法,即将负极材料与金属锂或者其他低电势的含锂化学试剂进行氧化还原反应,弥补锂的损失。因为电解液的环境中,由于金属锂与负极材料的电势差使得锂离子流定向移动,其中锂箔产生的锂离子被释放到电解液中,为保持电荷守恒,电解液中的锂离子嵌入负极或者与其发生氧化还原反应,使负极完成预锂化。虽然该方案工艺简单、补锂效率高,但金属锂容量非常高、且由于技术限制,使得补充锂源的面容量远远超过实际需要的活性锂离子容量,另外锂箔和其他低电势的含锂化试剂活性都较高,易与空气中的水、空气等其他气体反应,安全隐患非常大,很难与现有装配工艺兼容。At present, the method that has been studied the most is the negative electrode chemical method, which is to conduct an oxidation-reduction reaction between the negative electrode material and metallic lithium or other low-potential lithium-containing chemical reagents to make up for the loss of lithium. Because in the electrolyte environment, the potential difference between metallic lithium and the negative electrode material causes the lithium ion flow to move in a directional manner, and the lithium ions generated by the lithium foil are released into the electrolyte. In order to maintain charge conservation, the lithium ions in the electrolyte are embedded in the negative electrode or undergo an oxidation-reduction reaction with it, so that the negative electrode is pre-lithiated. Although this solution has a simple process and high lithium replenishment efficiency, the capacity of metallic lithium is very high, and due to technical limitations, the surface capacity of the supplemented lithium source far exceeds the actual required active lithium ion capacity. In addition, lithium foil and other low-potential lithium-containing reagents are highly active and easily react with water, air and other gases in the air. The safety hazard is very large and it is difficult to be compatible with existing assembly processes.
最近,正极预锂化法吸引了众多研究者的关注,其是将正极预锂化试剂添加到正极材料中,首次充电时,分子中具有高锂离子含量的预锂化试剂不可逆的脱出活性锂离子用于弥补负极材料的首次不可逆锂消耗,从而提升电池能量密度;正极预锂化试剂可借用现有的生产工艺与正极材料进行共混,能根据添加含量精准控制补锂容量,安全性高。因为其工艺简单,与现有电池工艺完美兼容,能有效提升全电池能量密度,还能精准控制预锂化锂离子的容量,非常有利于大规模的商业应用。Recently, the positive electrode pre-lithiation method has attracted the attention of many researchers. It is to add positive electrode pre-lithiation reagents to positive electrode materials. During the first charge, the pre-lithiation reagents with high lithium ion content in the molecule irreversibly release active lithium ions to make up for the first irreversible lithium consumption of the negative electrode material, thereby improving the battery energy density. The positive electrode pre-lithiation reagents can be blended with positive electrode materials using existing production processes, and the lithium replenishment capacity can be accurately controlled according to the added content, with high safety. Because of its simple process and perfect compatibility with existing battery processes, it can effectively improve the energy density of the entire battery, and can also accurately control the capacity of pre-lithiation lithium ions, which is very conducive to large-scale commercial applications.
目前,正极补锂常用方案是将补锂试剂与正极材料在配料均浆阶段进行共混,利用补锂试剂首次充电时脱出的多余锂离子来弥补电芯的活性锂离子消耗,提升电芯能量密度和循环寿命。但是,大部分正极补锂剂都存在导电性差的问题,如Li2S、Li2O、Li2O2、LiF、Li5FeO4、Li2NiO2,其必须要与较高比例的导电剂结合才能有效的脱出其所包含的锂离子。仅简单的将正极补锂试剂与正极活性材料进行简单的共混,补锂试剂首次脱出的锂离子较理论容量低;另外因补锂试剂脱锂后残留的低导电性物质,使得正极极片电阻增加,恶化正极活性物质本身克容量的发挥,最后使得电芯的能量密度改善不理想,且会恶化电芯的循环寿命。另外CN 107068972 A将补锂材料层涂覆在正极材料层表面,虽然可以分别调整正极材料、补锂材料与导电剂的比例,改善补锂试剂的容量发挥,但是涂覆在正极材料表面的补锂材料层会阻碍锂离子的传导,增加正极材料锂离子进入负极材料的传输距离,导致充放电时的浓差极化,恶化电芯电化学性能;同时CN109686947A直接在集流体表面设置补锂层,可以避免补锂层恶化锂离子传导,但是因为常用的无机补锂材料本身导电性差,这会恶化电子传导速率,增加电池物理内阻,且这两种方法都必须进行多次涂覆,增加工艺成本。At present, the common scheme for positive electrode lithium replenishment is to blend the lithium replenishment agent with the positive electrode material in the batching homogenization stage, and use the excess lithium ions released by the lithium replenishment agent during the first charge to compensate for the active lithium ion consumption of the battery cell, thereby improving the energy density and cycle life of the battery cell. However, most positive electrode lithium replenishers have the problem of poor conductivity, such as Li 2 S, Li 2 O, Li 2 O 2 , LiF, Li 5 FeO 4 , and Li 2 NiO 2 , which must be combined with a higher proportion of conductive agents to effectively release the lithium ions they contain. Simply blending the positive electrode lithium replenishment agent with the positive electrode active material will result in the lithium ions released by the lithium replenishment agent for the first time being lower than the theoretical capacity; in addition, due to the low-conductivity substances remaining after the lithium replenishment agent is de-lithiated, the resistance of the positive electrode sheet increases, which deteriorates the performance of the gram capacity of the positive electrode active material itself, and finally makes the energy density of the battery cell unsatisfactory and deteriorates the cycle life of the battery cell. In addition, CN 107068972 A coats the lithium supplement material layer on the surface of the positive electrode material layer. Although the ratio of the positive electrode material, the lithium supplement material and the conductive agent can be adjusted respectively to improve the capacity of the lithium supplement agent, the lithium supplement material layer coated on the surface of the positive electrode material will hinder the conduction of lithium ions, increase the transmission distance of lithium ions from the positive electrode material to the negative electrode material, lead to concentration polarization during charging and discharging, and deteriorate the electrochemical performance of the battery cell; at the same time, CN109686947A directly sets the lithium supplement layer on the surface of the current collector, which can avoid the lithium supplement layer from deteriorating the lithium ion conduction, but because the commonly used inorganic lithium supplement material itself has poor conductivity, this will deteriorate the electronic conduction rate and increase the physical internal resistance of the battery, and both methods must be coated multiple times, increasing the process cost.
发明内容Summary of the invention
针对现有技术中存在的问题,本发明提供了一种补锂正极极片及其制备方法与锂离子电池,将正极活性物质和补锂剂分开均浆,根据各自的电子传导特点匹配不同的导电剂含量,然后将两种浆料通过挤压涂布一次性涂覆在正极集流体上;并且补锂材料纵向分布(垂直于集流体宽度方向),既不影响正极材料层的电子传导,也不会恶化锂离子的传输路径,同时因为补锂层的导电剂含量多,孔隙率大,使得纵向补锂材料层中电解液更多,这样正极材料的锂离子可以通过补锂层中的电解液快速脱出,改善快充、放电时的浓差极化;这样该方法不仅使得正极活性物质和补锂剂各自性能最大化的发挥,互不影响,最大化的提升补锂剂的作用,提升电芯能量密度和循环寿命;同时工艺简单,可以根据补锂量的需求灵活设计,且一次完成正极材料和补锂试剂的涂覆,加工成本低。In view of the problems existing in the prior art, the present invention provides a lithium-supplemented positive electrode sheet and a preparation method thereof and a lithium-ion battery, wherein the positive electrode active material and the lithium supplement agent are separated and homogenized, and different conductive agent contents are matched according to their respective electronic conduction characteristics, and then the two slurries are coated on the positive electrode current collector at one time by extrusion coating; and the lithium supplement material is distributed longitudinally (perpendicular to the width direction of the current collector), which neither affects the electronic conduction of the positive electrode material layer nor deteriorates the transmission path of lithium ions. At the same time, because the conductive agent content of the lithium supplement layer is high and the porosity is large, there is more electrolyte in the longitudinal lithium supplement material layer, so that the lithium ions of the positive electrode material can be quickly released through the electrolyte in the lithium supplement layer, thereby improving the concentration polarization during fast charging and discharging; in this way, the method not only maximizes the performance of the positive electrode active material and the lithium supplement agent, without affecting each other, but also maximizes the effect of the lithium supplement agent, thereby improving the energy density and cycle life of the battery cell; at the same time, the process is simple, can be flexibly designed according to the demand for lithium supplementation, and the coating of the positive electrode material and the lithium supplement agent is completed at one time, with low processing cost.
为了实现上述目的,本发明采用以下技术方案。In order to achieve the above object, the present invention adopts the following technical solutions.
一种补锂正极极片,所述正极极片包括正极集流体、涂覆在所述正极集流体上的正极活性物质层和补锂试剂层,其中,单条所述补锂试剂层和单条所述正极活性物质层均沿集流体长度方向布设,所述补锂试剂层与所述正极活性物质层在所述集流体表面上沿集流体宽度方向间隔排布。A lithium-replenishing positive electrode plate, comprising a positive current collector, a positive active material layer coated on the positive current collector, and a lithium-replenishing reagent layer, wherein a single lithium-replenishing reagent layer and a single positive active material layer are both arranged along the length direction of the current collector, and the lithium-replenishing reagent layer and the positive active material layer are arranged at intervals on the surface of the current collector along the width direction of the current collector.
上述补锂正极极片,作为一种优选实施方式,补锂试剂层条数根据实际的补锂量进行调整,补锂试剂层的条数可为1-5条(例如,2条、3条、4条),补锂试剂层宽度为0.5mm-30mm(例如,1mm、5mm、10mm、15mm、20mm、25mm)。As a preferred embodiment, the number of lithium replenishing reagent layers of the above-mentioned lithium replenishing positive electrode plate is adjusted according to the actual amount of lithium replenishment, the number of lithium replenishing reagent layers can be 1-5 (for example, 2, 3, 4), and the width of the lithium replenishing reagent layer is 0.5mm-30mm (for example, 1mm, 5mm, 10mm, 15mm, 20mm, 25mm).
上述补锂正极极片,作为一种优选实施方式,补锂试剂层包括补锂试剂、第一导电剂、第一粘结剂。As a preferred embodiment, the lithium-replenishing positive electrode plate comprises a lithium-replenishing reagent layer including a lithium-replenishing reagent, a first conductive agent, and a first binder.
上述补锂正极极片,作为一种优选实施方式,所述补锂试剂层中,所述补锂试剂包括Li2S、Li2O、Li2O2、LiF、Li1+a1FeO4(0<a1≤5),Li1+a2 NiO2(0<a2≤3),Li1+a3NixCoyMnzO2(0<a3≤3,0≤x≤1,0≤y≤1,0≤z≤1,且x+y+z=1)中的任意一种或多种。As a preferred embodiment, the above-mentioned lithium-replenishing positive electrode plate, in the lithium-replenishing reagent layer, the lithium-replenishing reagent includes any one or more of Li2S , Li2O , Li2O2 , LiF , Li1 + a1FeO4 (0< a1≤5 ), Li1 +a2NiO2 ( 0< a2≤3 ), Li1 + a3NixCoyMnzO2 (0< a3≤3, 0≤x≤1 , 0≤y≤1, 0≤z≤1, and x+y+z=1).
上述补锂正极极片,作为一种优选实施方式,所述补锂试剂层中,补锂试剂、第一导电剂和第一粘结剂的质量比例为60-95(例如,65、70、80、85、88):2-30(例如,5、10、15、20、25、28):2-15(例如,3、5、10、12、14),且比例之和等于100。The above-mentioned lithium-supplemented positive electrode plate, as a preferred embodiment, in the lithium-supplementing reagent layer, the mass ratio of the lithium-supplementing reagent, the first conductive agent and the first binder is 60-95 (for example, 65, 70, 80, 85, 88): 2-30 (for example, 5, 10, 15, 20, 25, 28): 2-15 (for example, 3, 5, 10, 12, 14), and the sum of the ratios is equal to 100.
上述补锂正极极片,作为一种优选实施方式,所述补锂试剂层的厚度与正极活性物质的厚度相同,或者比正极活性物质的厚度低1μm-20μm(例如,3μm、5μm、10μm、15μm、18μm)。As a preferred embodiment, the thickness of the lithium-replenishing reagent layer of the above-mentioned lithium-replenishing positive electrode plate is the same as the thickness of the positive electrode active material, or is 1μm-20μm (for example, 3μm, 5μm, 10μm, 15μm, 18μm) lower than the thickness of the positive electrode active material.
本发明中,采用与正极活性物质的厚度相同或低的补锂试剂层的厚度,特别是比正极活性物质的厚度低的补锂试剂层的厚度,有利于提升正极极片的保液率,改善正极的浓差极化,提升正极放电容量和倍率性能。In the present invention, the thickness of the lithium replenishing reagent layer is the same as or lower than the thickness of the positive electrode active material, especially the thickness of the lithium replenishing reagent layer is lower than the thickness of the positive electrode active material, which is beneficial to improving the liquid retention rate of the positive electrode plate, improving the concentration polarization of the positive electrode, and improving the discharge capacity and rate performance of the positive electrode.
上述补锂正极极片,作为一种优选实施方式,所述正极活性物质层和所述补锂试剂层可以涂覆在所述正极集流体的任意一侧表面或两侧表面上。As a preferred embodiment of the lithium-supplementing positive electrode sheet, the positive electrode active material layer and the lithium-supplementing reagent layer can be coated on any one side surface or both sides surface of the positive electrode current collector.
上述补锂正极极片,作为一种优选实施方式,所述补锂试剂层为2-4条(例如,3条),宽度1-10mm(例如,1mm、3mm、5mm、6mm、7mm、8mm、9mm)。As a preferred embodiment, the lithium-replenishing positive electrode plate has 2-4 (for example, 3) lithium-replenishing reagent layers with a width of 1-10 mm (for example, 1 mm, 3 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm).
上述补锂正极极片,作为一种优选实施方式,正极活性物质层包含正极活性材料、第二导电剂、第二粘结剂;其中,在正极活性物质层中,按质量百分比计,正极活性物质为90-98%(例如,92%、94%、95%、97%),第二导电剂为0.5-5wt%(例如,1wt%、2wt%、3wt%、4wt%),第二粘结剂为0.5-5wt%(例如,1wt%、2wt%、3wt%、4wt%)。The above-mentioned lithium-supplemented positive electrode plate, as a preferred embodiment, the positive electrode active material layer comprises a positive electrode active material, a second conductive agent, and a second binder; wherein, in the positive electrode active material layer, by mass percentage, the positive electrode active material is 90-98% (for example, 92%, 94%, 95%, 97%), the second conductive agent is 0.5-5wt% (for example, 1wt%, 2wt%, 3wt%, 4wt%), and the second binder is 0.5-5wt% (for example, 1wt%, 2wt%, 3wt%, 4wt%).
上述补锂正极极片,作为一种优选实施方式,所述补锂正极极片中,正极活性物质层和补锂试剂层的质量比例为(90-99):(1-10)(例如,92:8、94:6、95:5、96:4、97:3、98:2)。As a preferred embodiment, the above-mentioned lithium-supplemented positive electrode plate has a mass ratio of the positive electrode active material layer and the lithium-supplementing reagent layer of (90-99):(1-10) (for example, 92:8, 94:6, 95:5, 96:4, 97:3, 98:2).
上述补锂正极极片,作为一种优选实施方式,所述正极活性物质层中,正极活性材料包括三元正极材料LixMyO2(x取值为1~2,y为1~2),钴酸锂、锰酸锂、磷酸铁锂、磷酸锰铁锂(LiMnzFe1-zPO4,z取值为0.2-0.8)中的一种或多种组合,或者以上这些材料的掺杂型正极材料,其中M包括Ni、Mn、Co、Al、Mg、Zr中的一种或多种。As a preferred embodiment, the above-mentioned lithium-supplemented positive electrode plate, in the positive electrode active material layer, the positive electrode active material includes one or more combinations of ternary positive electrode material Li x M y O 2 (x is 1 to 2, y is 1 to 2), lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, lithium manganese iron phosphate (LiMn z Fe 1-z PO 4 , z is 0.2-0.8), or doped positive electrode materials of the above materials, wherein M includes one or more of Ni, Mn, Co, Al, Mg, and Zr.
上述补锂正极极片,作为一种优选实施方式,所述第一粘结剂或所述第二粘结剂包括聚偏氟乙烯、聚四氟乙烯、聚丙烯酸、聚丙烯酸锂、聚丙烯酸钠、羧甲基纤维素、丁苯橡胶中的一种或者多种组合。As a preferred embodiment of the lithium-supplemented positive electrode plate, the first binder or the second binder includes one or a combination of polyvinylidene fluoride, polytetrafluoroethylene, polyacrylic acid, lithium polyacrylate, sodium polyacrylate, carboxymethyl cellulose, and styrene-butadiene rubber.
上述补锂正极极片,作为一种优选实施方式,所述第一导电剂或所述第二导电剂包括导电炭黑、乙炔黑、科琴黑、导电石墨、导电碳纤维、碳纳米管、石墨烯、金属粉或碳纤维中的至少一种。As a preferred embodiment of the lithium-supplemented positive electrode plate, the first conductive agent or the second conductive agent includes at least one of conductive carbon black, acetylene black, Ketjen black, conductive graphite, conductive carbon fiber, carbon nanotubes, graphene, metal powder or carbon fiber.
本发明还提供了一种上述补锂正极极片的制备方法,采用如下技术方案。The present invention also provides a method for preparing the above-mentioned lithium-supplemented positive electrode plate, which adopts the following technical scheme.
一种上述补锂正极极片的制备方法,包括如下步骤:A method for preparing the above-mentioned lithium-supplemented positive electrode sheet comprises the following steps:
(1)正极活性物质层浆料的制备(1) Preparation of positive electrode active material layer slurry
按照上述配方将正极活性物质、第二导电剂和第二粘结剂加入到第二溶剂中,充分搅拌,获得正极活性物质层浆料;According to the above formula, the positive electrode active material, the second conductive agent and the second binder are added to the second solvent, and stirred sufficiently to obtain a positive electrode active material layer slurry;
(2)补锂试剂层浆料的制备(2) Preparation of lithium supplementation reagent layer slurry
按照上述配方将补锂试剂、第一导电剂和第一粘结剂加入到第一溶剂中,充分搅拌,获得正极补锂试剂的活性浆料;According to the above formula, the lithium replenishing agent, the first conductive agent and the first binder are added to the first solvent, and stirred sufficiently to obtain an active slurry of the positive electrode lithium replenishing agent;
(3)补锂正极极片的制备(3) Preparation of lithium-supplemented positive electrode sheets
按照补锂正极极片设计需求,将所述正极活性物质层浆料和补锂试剂层浆料一次涂覆于正极集流体的任意一侧或两侧表面上,得到所述补锂正极极片。According to the design requirements of the lithium-replenishing positive electrode sheet, the positive electrode active material layer slurry and the lithium-replenishing reagent layer slurry are coated on any one side or both sides of the positive electrode collector at one time to obtain the lithium-replenishing positive electrode sheet.
上述补锂正极极片的制备方法中,作为一种优选实施方式,所述步骤(3)中,通过常规挤压涂布机和设计的挤压垫片将所述正极活性物质层浆料和补锂试剂层浆料一次涂覆于正极集流体的任意一侧或两侧表面上,得到所述补锂正极极片。In the above-mentioned method for preparing the lithium-replenishing positive electrode sheet, as a preferred embodiment, in the step (3), the positive electrode active material layer slurry and the lithium-replenishing reagent layer slurry are coated on any one side or both sides of the positive electrode collector at one time by a conventional extrusion coater and a designed extrusion gasket to obtain the lithium-replenishing positive electrode sheet.
上述补锂正极极片的制备方法中,作为一种优选实施方式,所述步骤(3)中,当在正极集流体一侧涂覆完成正极活性物质层和补锂试剂层后,再在正极集流体的另一侧涂覆正极活性物质层和补锂试剂层。In the above-mentioned method for preparing the lithium-supplemented positive electrode sheet, as a preferred embodiment, in the step (3), after the positive electrode active material layer and the lithium-supplementing reagent layer are coated on one side of the positive electrode current collector, the positive electrode active material layer and the lithium-supplementing reagent layer are coated on the other side of the positive electrode current collector.
上述补锂正极极片的制备方法中,作为一种优选实施方式,所述步骤(3)在涂覆完成后还包括干燥、冷压、分条、裁切,得到正极极片。In the above-mentioned method for preparing the lithium-supplemented positive electrode sheet, as a preferred embodiment, the step (3) further comprises drying, cold pressing, slitting, and cutting after coating is completed to obtain the positive electrode sheet.
上述补锂正极极片的制备方法中,作为一种优选实施方式,所述步骤(1)或(2)中,所述搅拌在真空搅拌机中进行。In the above-mentioned method for preparing the lithium-supplemented positive electrode sheet, as a preferred embodiment, in the step (1) or (2), the stirring is carried out in a vacuum mixer.
由于大部分正极补锂剂都存在导电性差的问题,如Li2S、Li2O、Li2O2、LiF、Li5FeO4、Li2NiO2,其必须要与较高比例的导电剂结合才能有效的脱出其所包含的锂离子。仅简单的将正极补锂试剂与正极活性材料进行共混,补锂试剂脱出的锂离子较理论容量低;另外因补锂试剂脱锂后残留的低导电性物质,使得正极极片电阻增加,恶化正极活性物质本身克容量的发挥,最后使得电芯的能量密度改善不理想。因此,本发明将正极活性物质和补锂剂分开均浆,根据各自特点匹配不同的配方,然后将两种浆料通过挤压涂布一次性涂覆(涂覆)在正极集流体一侧表面上。该方法不仅使得正极活性物质和补锂剂各自性能最大化的发挥,互不影响,最大化的提升补锂剂的作用,提升电芯能量密度和循环寿命;同时工艺简单,可以根据补锂量不同灵活设计,且一次完成正极材料和补锂试剂在正极集流体一侧表面的涂覆,加工成本低。Since most positive electrode lithium replenishers have poor conductivity, such as Li 2 S, Li 2 O, Li 2 O 2 , LiF, Li 5 FeO 4 , and Li 2 NiO 2 , they must be combined with a higher proportion of conductive agents to effectively release the lithium ions they contain. If the positive electrode lithium replenisher is simply blended with the positive electrode active material, the lithium ions released by the lithium replenisher are lower than the theoretical capacity; in addition, due to the low-conductivity substances remaining after the lithium replenisher is de-lithiated, the resistance of the positive electrode sheet increases, which deteriorates the performance of the gram capacity of the positive electrode active material itself, and finally makes the energy density of the battery cell unsatisfactory. Therefore, the present invention separates the positive electrode active material and the lithium replenisher into slurries, matches different formulas according to their respective characteristics, and then applies the two slurries (coating) on the surface of one side of the positive electrode current collector at one time by extrusion coating. This method not only maximizes the performance of the positive electrode active material and the lithium replenisher without affecting each other, but also maximizes the effect of the lithium replenisher and improves the energy density and cycle life of the battery cell. At the same time, the process is simple and can be flexibly designed according to the amount of lithium replenishment. The positive electrode material and the lithium replenisher can be coated on the surface of one side of the positive electrode current collector at one time, and the processing cost is low.
本发明中,所述步骤(3)中,也可以采用将正极活性物质层浆料或补锂试剂层浆料涂覆在正极集流体一侧或两侧后,再涂覆补锂试剂层浆料或正极活性物质层浆料于正极集流体一侧或两侧,从而得到所述补锂正极极片;即,采用在正极集流体一侧或两侧分别涂覆正极活性物质层浆料或补锂试剂层浆料的方法。In the present invention, in the step (3), the positive electrode active material layer slurry or the lithium replenishing reagent layer slurry can also be coated on one side or both sides of the positive electrode current collector, and then the lithium replenishing reagent layer slurry or the positive electrode active material layer slurry is coated on one side or both sides of the positive electrode current collector to obtain the lithium replenishing positive electrode plate; that is, the method of coating the positive electrode active material layer slurry or the lithium replenishing reagent layer slurry on one side or both sides of the positive electrode current collector is adopted.
本发明另一方面还提供了一种锂离子电池,包括正极极片、隔离膜和负极极片,所述正极极片采用上述补锂正极极片。Another aspect of the present invention provides a lithium-ion battery, comprising a positive electrode plate, a separator and a negative electrode plate, wherein the positive electrode plate adopts the above-mentioned lithium-supplementing positive electrode plate.
本发明中,在相互不冲突的条件下,上述技术特征可以自由组合形成新的技术方案。In the present invention, under the condition that they do not conflict with each other, the above technical features can be freely combined to form a new technical solution.
相对于现有技术,本发明的有益技术效果如下:Compared with the prior art, the beneficial technical effects of the present invention are as follows:
1.本发明将正极活性物质和补锂试剂分开均浆,根据各自电子传导特点匹配不同的导电剂含量,然后将两种浆料通过挤压涂布一次性涂覆在正极集流体一侧表面上,这样不仅使得正极活性物质和补锂剂各自性能最大化的发挥,互不影响,最大化的提升补锂试剂的作用,提升电芯能量密度和循环寿命;1. The present invention separates and homogenizes the positive electrode active material and the lithium replenishing agent, matches different conductive agent contents according to their respective electronic conduction characteristics, and then applies the two slurries on the surface of one side of the positive electrode current collector at one time by extrusion coating. This not only maximizes the performance of the positive electrode active material and the lithium replenishing agent, but also does not affect each other, maximizes the effect of the lithium replenishing agent, and improves the energy density and cycle life of the battery cell;
2.单条补锂试剂层纵向分布(垂直于集流体宽度方向,即沿集流体长度方向布设),既不影响正极活性物质层与集流体之间的电子传导,也不会恶化锂离子的传输路径,同时因为补锂试剂层的导电剂含量多,孔隙率大,使得纵向补锂试剂层中电解液更多,这样正极材料的锂离子可以通过补锂试剂层中的电解液快速脱出,改善快充时的浓差极化;2. The single lithium replenishing reagent layer is distributed longitudinally (perpendicular to the width direction of the current collector, i.e., arranged along the length direction of the current collector), which neither affects the electronic conduction between the positive electrode active material layer and the current collector, nor deteriorates the transmission path of lithium ions. At the same time, because the lithium replenishing reagent layer has a high content of conductive agent and a large porosity, there is more electrolyte in the longitudinal lithium replenishing reagent layer, so that the lithium ions of the positive electrode material can be quickly released through the electrolyte in the lithium replenishing reagent layer, thereby improving the concentration polarization during fast charging;
3.本发明中补锂正极极片的制备工艺简单,可以根据补锂量不同灵活设计,且一次完成正极活性物质层和补锂试剂层在正极集流体一侧表面的涂覆,加工成本低。3. The preparation process of the lithium-supplemented positive electrode sheet in the present invention is simple, and can be flexibly designed according to different lithium replenishment amounts. The positive electrode active material layer and the lithium replenishment reagent layer are coated on the surface of one side of the positive electrode current collector at one time, and the processing cost is low.
附图说明BRIEF DESCRIPTION OF THE DRAWINGS
图1为本发明正极极片沿集流体宽度方向的剖面图;FIG1 is a cross-sectional view of a positive electrode sheet of the present invention along the width direction of the current collector;
图2为本发明正极极片的俯视图;FIG2 is a top view of the positive electrode sheet of the present invention;
图3为根据本发明的锂离子电池(即电芯)正负极极片、隔膜组合示意图;FIG3 is a schematic diagram of the positive and negative electrode sheets and the separator assembly of a lithium-ion battery (i.e., a battery cell) according to the present invention;
附图标记说明:1为集流体;2为补锂试剂层;3为正极活性物质层;4为隔膜;5为负极极片。Explanation of reference numerals: 1 is a current collector; 2 is a lithium replenishing reagent layer; 3 is a positive electrode active material layer; 4 is a separator; 5 is a negative electrode plate.
具体实施方式DETAILED DESCRIPTION
下面将结合实施例来详细说明本发明。各个示例通过本发明的解释的方式提供而非限制本发明。实际上,本领域的技术人员将清楚,在不脱离本发明的范围或精神的情况下,可在本发明中进行修改和变型。例如,示为或描述为一个实施例的一部分的特征可用于另一个实施例,以产生又一个实施例。因此,所期望的是,本发明包含归入所附权利要求及其等同物的范围内的此类修改和变型。The present invention will be described in detail below in conjunction with the embodiments. Each example is provided by way of explanation of the present invention and does not limit the present invention. In fact, it will be clear to those skilled in the art that modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature shown or described as a part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desired that the present invention includes such modifications and variations within the scope of the appended claims and their equivalents.
本发明中,所述试剂和材料,如无特殊说明,均可从商业途径获得。本发明中,未详细描述的部分可以采用本领域的常规技术方案。In the present invention, the reagents and materials, unless otherwise specified, can be obtained from commercial sources. In the present invention, parts not described in detail can adopt conventional technical solutions in the art.
如图1-2中补锂正极极片的剖面图和俯视图所示,一种补锂正极极片,包括正极集流体1、涂覆在正极集流体表面上的补锂试剂层2和正极活性物质层3,其中,单条补锂试剂层和单条正极活性物质层都沿集流体长度方向布设,即在集流体表面上形成的补锂试剂层和正极活性物质层的长度方向与集流体的长度方向一致,补锂试剂层与正极活性物质层在集流体表面上沿集流体宽度方向间隔排布,即在一个集流体上包括多条沿集流体长度方向布设的补锂试剂层和多条正极活性物质层,多条补锂试剂层和多条正极活性物质层沿集流体宽度方向交替排列。As shown in the cross-sectional view and top view of the lithium-replenishing positive electrode sheet in Figures 1-2, a lithium-replenishing positive electrode sheet comprises a positive current collector 1, a lithium-replenishing
如图3所示,一种锂离子电池(即电芯),包括正极极片、隔离膜4和负极极片5,正极极片包括正极集流体1、涂覆在正极集流体表面上的补锂试剂层2和正极活性物质层3。As shown in FIG3 , a lithium-ion battery (i.e., a battery cell) includes a positive electrode plate, a separator 4 and a
实施例1Example 1
正极极片的制备Preparation of positive electrode
将正极活性材料LiFePO4、导电炭黑Super-P、粘结剂PVDF按重量比97.3:1.5:1.2在N-甲基吡咯烷酮NMP溶剂体系中,通过真空搅拌机进行充分搅拌,获得正极活性物质层浆料;The positive electrode active material LiFePO 4 , the conductive carbon black Super-P, and the binder PVDF are mixed in a N-methylpyrrolidone (NMP) solvent system in a weight ratio of 97.3:1.5:1.2 by a vacuum mixer to obtain a positive electrode active material layer slurry;
按照配方将补锂试剂、导电炭黑和聚偏氟乙烯(PVDF)加入到N-甲基吡咯烷酮NMP溶剂中,充分搅拌,获得补锂试剂层浆料;在干燥后的正极极片中,补锂试剂层占正极活性物质层和补锂试剂层总重量的4%(即,补锂试剂层的添加比例);具体参见表1;According to the formula, a lithium replenishing reagent, conductive carbon black and polyvinylidene fluoride (PVDF) are added to N-methylpyrrolidone NMP solvent and stirred thoroughly to obtain a lithium replenishing reagent layer slurry; in the dried positive electrode sheet, the lithium replenishing reagent layer accounts for 4% of the total weight of the positive electrode active material layer and the lithium replenishing reagent layer (i.e., the addition ratio of the lithium replenishing reagent layer); see Table 1 for details;
如图1所示,通过常规挤压涂布机和设计的挤压垫片将所述正极浆料和补锂试剂层浆料一次性涂覆于12μm厚Al箔基材的任意一侧,干燥后在12μmAl箔基材的另一侧一次性涂覆所述正极浆料和补锂试剂层浆料,然后通过干燥、冷压、分条、裁切,得到正极极片。其中,正极活性物质层的条数是3,每条宽度20mm,厚度186μm;补锂试剂层的条数是2,每条宽度1.3mm,厚度186μm。As shown in Figure 1, the positive electrode slurry and the lithium replenishing reagent layer slurry are coated on either side of a 12μm thick Al foil substrate at one time by a conventional extrusion coating machine and a designed extrusion gasket, and then the positive electrode slurry and the lithium replenishing reagent layer slurry are coated on the other side of the 12μm Al foil substrate at one time after drying, and then dried, cold pressed, striped, and cut to obtain a positive electrode sheet. Among them, the number of strips of the positive electrode active material layer is 3, each with a width of 20mm and a thickness of 186μm; the number of strips of the lithium replenishing reagent layer is 2, each with a width of 1.3mm and a thickness of 186μm.
负极极片的制备Preparation of negative electrode
将所述负极活性材料(95%wt石墨+5%wt硅碳)、导电剂、丁苯橡胶和羧甲基纤维素钠(粘结剂)按重量比96.5:1:1.2:1.3的比例溶于去离子水中,充分搅拌混合均匀后得到含有所述第一负极活性浆料;The negative electrode active material (95%wt graphite + 5%wt silicon carbon), conductive agent, styrene-butadiene rubber and sodium carboxymethyl cellulose (binder) are dissolved in deionized water in a weight ratio of 96.5:1:1.2:1.3, and the mixture is stirred and mixed to obtain a slurry containing the first negative electrode active material;
将含有负极活性材料的负极浆料和导热浆料通过特殊设计的挤压涂布机涂覆于负极集流体6μm厚的Cu箔的表面上,依次经过干燥、冷压、裁切后,即得具有双层活性物质层的负极极片,冷压后,冷压后负极极片厚度为130μm。The negative electrode slurry and thermal conductive slurry containing the negative electrode active material are coated on the surface of the 6μm thick Cu foil of the negative electrode current collector by a specially designed extrusion coater. After drying, cold pressing and cutting, the negative electrode sheet with a double-layer active material layer is obtained. After cold pressing, the thickness of the negative electrode sheet is 130μm.
电解液的制备Preparation of electrolyte
将碳酸乙烯酯(EC)、碳酸甲乙酯(EMC)、碳酸二甲酯(DMC)按照体积比3:3:4进行混合得到有机溶剂,接着将充分干燥的LiPF6溶解于混合后的有机溶剂中,配制成LiPF6浓度1mol/L的电解液。Ethylene carbonate (EC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC) are mixed in a volume ratio of 3:3:4 to obtain an organic solvent, and then fully dried LiPF6 is dissolved in the mixed organic solvent to prepare an electrolyte with a LiPF6 concentration of 1 mol/L.
隔离膜的制备Preparation of isolation membrane
隔离膜基材为8μm厚的聚乙烯(PE),在隔离膜基材的两侧各涂覆2μm氧化铝陶瓷层,最后在涂布了陶瓷层的两侧各涂覆2.5mg聚偏二氟乙烯(PVDF)粘结剂,烘干。The isolation membrane substrate is 8 μm thick polyethylene (PE), and a 2 μm alumina ceramic layer is coated on both sides of the isolation membrane substrate. Finally, 2.5 mg of polyvinylidene fluoride (PVDF) adhesive is coated on both sides of the ceramic layer and dried.
锂离子二次电池的制备Preparation of lithium-ion secondary batteries
将上述正极极片、隔离膜、负极极片按顺序叠好,使隔离膜处于正、负极极片之间起到隔离的作用,然后卷绕得到裸电芯;将合格裸电芯通过极耳焊接在顶盖上,置于外包装壳中,干燥后注入电解液,经过真空封装、静置、化成、整形等工序,获得软包型的锂离子二次电池,其容量约为5000mAh。The positive electrode sheet, isolation film and negative electrode sheet are stacked in order, so that the isolation film is placed between the positive and negative electrode sheets to play an isolating role, and then wound to obtain a bare battery cell; the qualified bare battery cell is welded to the top cover through the pole ear, placed in an outer packaging shell, and injected with electrolyte after drying. After vacuum packaging, standing, forming, shaping and other processes, a soft-pack lithium-ion secondary battery with a capacity of about 5000mAh is obtained.
实施例2Example 2
实施例2与实施例1不同的是,正极活性物质为LiNi0.8Co0.1Mn0.1O2,补锂试剂层占正极活性物质层和补锂试剂层总质量的3%(即,补锂试剂层的添加比例);正极活性物质、导电炭黑与聚偏氟乙烯的质量比例为97.6:1.3:1.1,其他技术方案与实施例1中的相同,具体参见表1。The difference between Example 2 and Example 1 is that the positive electrode active material is LiNi 0.8 Co 0.1 Mn 0.1 O 2 , and the lithium replenishing reagent layer accounts for 3% of the total mass of the positive electrode active material layer and the lithium replenishing reagent layer (that is, the addition ratio of the lithium replenishing reagent layer); the mass ratio of the positive electrode active material, the conductive carbon black and the polyvinylidene fluoride is 97.6:1.3:1.1, and the other technical schemes are the same as those in Example 1, see Table 1 for details.
本实施例制备的正极极片中,正极活性物质层的条数3,每条宽度20mm,厚度110μm;补锂试剂层的条数是2,每条宽度1mm,厚度110μm。In the positive electrode sheet prepared in this embodiment, the number of positive electrode active material layers is 3, each with a width of 20 mm and a thickness of 110 μm; the number of lithium supplement reagent layers is 2, each with a width of 1 mm and a thickness of 110 μm.
实施例3Example 3
实施例3与实施例1不同的是,补锂试剂层中,补锂试剂、导电炭黑与聚偏氟乙烯的质量比例为95:3:2,其他技术方案与实施例1中的相同,具体参见表1。The difference between Example 3 and Example 1 is that in the lithium replenishing reagent layer, the mass ratio of the lithium replenishing reagent, the conductive carbon black and the polyvinylidene fluoride is 95:3:2, and the other technical schemes are the same as those in Example 1, see Table 1 for details.
本实施例制备的正极极片中,正极活性物质层的条数是3,每条宽度20mm,厚度186μm;补锂试剂层的条数是2,每条宽度1.3mm,厚度186μm。In the positive electrode sheet prepared in this embodiment, the number of positive electrode active material layers is 3, each with a width of 20 mm and a thickness of 186 μm; the number of lithium supplement reagent layers is 2, each with a width of 1.3 mm and a thickness of 186 μm.
实施例4Example 4
实施例4与实施例1不同的是,补锂试剂层占正极活性物质层和补锂试剂层总重量的比例为3%;具体参见表1。The difference between Example 4 and Example 1 is that the proportion of the lithium replenishing reagent layer to the total weight of the positive electrode active material layer and the lithium replenishing reagent layer is 3%; see Table 1 for details.
本实施例制备的正极极片中,正极活性物质层的条数是3,每条宽度20mm,厚度186μm;补锂试剂层的条数是2,每条宽度1.0mm,厚度186μm。其他技术方案与实施例1中的相同。In the positive electrode sheet prepared in this embodiment, the number of positive electrode active material layers is 3, each with a width of 20 mm and a thickness of 186 μm; the number of lithium supplement reagent layers is 2, each with a width of 1.0 mm and a thickness of 186 μm. Other technical solutions are the same as those in Example 1.
实施例5Example 5
实施例5与实施例4不同的是,补锂试剂为Li2NiO2,补锂试剂、导电炭黑与聚偏氟乙烯的质量比例为90:7:3,其他技术方案与实施例4中的相同,具体参见表1。The difference between Example 5 and Example 4 is that the lithium supplementing agent is Li 2 NiO 2 , and the mass ratio of the lithium supplementing agent, conductive carbon black and polyvinylidene fluoride is 90:7:3. The other technical schemes are the same as those in Example 4, see Table 1 for details.
本实施例制备的正极极片中,正极活性物质层的条数是3,每条宽度20mm,厚度186μm;补锂试剂层的条数是2,每条宽度1.5mm,厚度110μm;In the positive electrode sheet prepared in this embodiment, the number of positive electrode active material layers is 3, each with a width of 20 mm and a thickness of 186 μm; the number of lithium supplement reagent layers is 2, each with a width of 1.5 mm and a thickness of 110 μm;
对比例1Comparative Example 1
本对比例与实施例1的区别在于,本对比例中,正极极片中不包含补锂试剂层。具体地,The difference between this comparative example and Example 1 is that in this comparative example, the positive electrode sheet does not contain a lithium supplementing reagent layer. Specifically,
正极极片的制备Preparation of positive electrode
将正极活性材料-LiFePO4、导电炭黑Super-P、粘结剂PVDF按重量比97.3:1.5:1.2在N-甲基吡咯烷酮NMP溶剂体系中,通过真空搅拌机进行充分搅拌,获得正极浆料;将所述正极浆料涂覆于12μm厚的Al箔基材的两个表面上,先后通过干燥、冷压、分条、裁切,得到正极极片。The positive electrode active material-LiFePO 4 , conductive carbon black Super-P, and binder PVDF are fully stirred in a N-methylpyrrolidone (NMP) solvent system in a weight ratio of 97.3:1.5:1.2 by a vacuum mixer to obtain a positive electrode slurry; the positive electrode slurry is coated on both surfaces of a 12 μm thick Al foil substrate, and then dried, cold pressed, slit, and cut to obtain a positive electrode sheet.
本对比例制备的正极极片中,正极活性物质层平铺在正极集流体的两侧表面上,厚度为186μm。In the positive electrode sheet prepared in this comparative example, the positive electrode active material layer is spread on both side surfaces of the positive electrode current collector, and the thickness is 186 μm.
对比例2Comparative Example 2
本对比例与实施例2的区别在于,本对比例中,正极极片中不包含补锂试剂层,正极浆料涂覆于12μm厚Al箔基材的两个表面上,形成具有平铺在Al箔基材的两侧表面上的正极活性物质层的正极极片。The difference between this comparative example and Example 2 is that in this comparative example, the positive electrode plate does not contain a lithium replenishing reagent layer, and the positive electrode slurry is coated on both surfaces of a 12 μm thick Al foil substrate to form a positive electrode plate having a positive electrode active material layer flattened on both side surfaces of the Al foil substrate.
本对比例制备的正极极片中,正极活性物质层平铺在正极集流体的两侧表面上,厚度为110μm。In the positive electrode sheet prepared in this comparative example, the positive electrode active material layer is spread on both side surfaces of the positive electrode current collector, and the thickness is 110 μm.
对比例3Comparative Example 3
本对比例与实施例1的区别在于,本对比例中,正极活性物质层和补锂试剂层在正极集流体表面的涂覆方式不同,本对比例中,补锂试剂层和正极活性物质层沿正极集流体的高度或厚度方向层叠设置。具体地:The difference between this comparative example and Example 1 is that in this comparative example, the coating method of the positive electrode active material layer and the lithium replenishing reagent layer on the surface of the positive electrode current collector is different. In this comparative example, the lithium replenishing reagent layer and the positive electrode active material layer are stacked along the height or thickness direction of the positive electrode current collector. Specifically:
将所述正极活性物质浆料涂覆于12μm厚的Al箔基材的两个表面上,得到两侧表面均含有正极活性物质层的正极集流体,干燥后在正极活性物质层表面涂覆补锂试剂层浆料,通过干燥、冷压、分条、裁切,得到在集流体两侧表面依次涂覆正极活性物质层和补锂试剂层的正极极片。The positive electrode active material slurry is coated on both surfaces of a 12 μm thick Al foil substrate to obtain a positive electrode current collector having positive electrode active material layers on both sides of the substrate; after drying, the lithium replenishing reagent layer slurry is coated on the surface of the positive electrode active material layer; and through drying, cold pressing, striping and cutting, a positive electrode sheet having positive electrode active material layers and lithium replenishing reagent layers sequentially coated on both sides of the current collector is obtained.
本对比例中,所得正极极片的正极活性物质层的厚度186μm,补锂试剂层的厚度8μm。In this comparative example, the thickness of the positive electrode active material layer of the obtained positive electrode sheet was 186 μm, and the thickness of the lithium replenishing agent layer was 8 μm.
对比例4Comparative Example 4
本对比例与实施例1的区别在于,本对比例中,正极活性物质层和补锂试剂层在正极集流体表面的涂覆方式不同,本对比例中,补锂试剂层和正极活性物质层沿正极集流体的高度或厚度方向层叠设置。具体地:The difference between this comparative example and Example 1 is that in this comparative example, the coating method of the positive electrode active material layer and the lithium replenishing reagent layer on the surface of the positive electrode current collector is different. In this comparative example, the lithium replenishing reagent layer and the positive electrode active material layer are stacked along the height or thickness direction of the positive electrode current collector. Specifically:
将补锂试剂层浆料涂覆于12μm厚的Al箔基材的两个表面上,得到两侧表面均含有补锂试剂层的正极集流体,干燥后在补锂试剂层表面涂覆正极活性物质浆料,通过干燥、冷压、分条、裁切,得到在正极集流体两侧表面依次涂覆补锂试剂层和正极活性物质层的正极极片。The lithium replenishing reagent layer slurry is coated on the two surfaces of a 12 μm thick Al foil substrate to obtain a positive electrode current collector with lithium replenishing reagent layers on both sides of the substrate; after drying, the positive electrode active material slurry is coated on the surface of the lithium replenishing reagent layer; through drying, cold pressing, striping and cutting, a positive electrode sheet with the lithium replenishing reagent layer and the positive electrode active material layer sequentially coated on the two sides of the positive electrode current collector is obtained.
本对比例中,所得正极极片的正极活性物质层的厚度186μm;补锂试剂层的厚度8μm。In this comparative example, the thickness of the positive electrode active material layer of the obtained positive electrode sheet is 186 μm; the thickness of the lithium supplement reagent layer is 8 μm.
电池的电化学性能测试Electrochemical performance test of batteries
在25℃条件下,将电池以1C放电至2.75V,静置1小时,以1C充电4.2V,静置1小时,然后以1C放电至2.75V并检测1C放电容量(即第一次循环时容量),用循环500次后的容量除以第一次循环时的容量计算容量保持率;用0.33C的倍率充电,然后0.33C倍率放电,放电时用容量乘以平均电压得到0.33C能量密度。表1列出了实施例1-5与对比例1-4中的主要工艺参数及电化学性能。At 25°C, the battery was discharged to 2.75V at 1C, left to stand for 1 hour, charged to 4.2V at 1C, left to stand for 1 hour, then discharged to 2.75V at 1C and the 1C discharge capacity (i.e., the capacity at the first cycle) was detected, and the capacity retention rate was calculated by dividing the capacity after 500 cycles by the capacity at the first cycle; charged at a rate of 0.33C, and then discharged at a rate of 0.33C, and the 0.33C energy density was obtained by multiplying the capacity by the average voltage during discharge. Table 1 lists the main process parameters and electrochemical properties of Examples 1-5 and Comparative Examples 1-4.
表1实施例1-5与对比例1-4中的主要工艺参数及电化学性能Table 1 Main process parameters and electrochemical performance of Examples 1-5 and Comparative Examples 1-4
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Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN116344979A (en) * | 2023-05-29 | 2023-06-27 | 江苏正力新能电池技术有限公司 | Positive electrode plate and preparation method and application thereof |
CN116705981A (en) * | 2023-07-27 | 2023-09-05 | 宁德时代新能源科技股份有限公司 | Negative electrode plate, preparation method thereof, battery and electric equipment |
WO2024212653A1 (en) * | 2023-12-22 | 2024-10-17 | 湖北亿纬动力有限公司 | Composite electrode sheet and preparation method therefor, and lithium-ion battery |
WO2024250640A1 (en) * | 2023-06-08 | 2024-12-12 | 宁德时代新能源科技股份有限公司 | Positive electrode sheet and preparation method therefor, secondary battery, and electric device |
WO2025000951A1 (en) * | 2023-06-25 | 2025-01-02 | 宁德时代新能源科技股份有限公司 | Positive electrode sheet, battery cell, battery, and electric device |
WO2025051253A1 (en) * | 2023-09-07 | 2025-03-13 | 湖北亿纬动力有限公司 | Battery cell and preparation method therefor, and lithium battery comprising battery cell |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102082288A (en) * | 2009-11-30 | 2011-06-01 | 比亚迪股份有限公司 | Lithium ion secondary battery and manufacture method thereof |
CN109616612A (en) * | 2018-12-05 | 2019-04-12 | 珠海格力电器股份有限公司 | Electrode and lithium ion battery |
CN113823849A (en) * | 2020-06-19 | 2021-12-21 | 比亚迪股份有限公司 | Lithium ion battery and lithium supplement positive plate thereof |
CN114175303A (en) * | 2021-03-26 | 2022-03-11 | 宁德新能源科技有限公司 | Positive pole piece, electrochemical device comprising positive pole piece and electronic device |
CN114267822A (en) * | 2021-11-25 | 2022-04-01 | 东莞市加伏新材料研究院有限公司 | Negative electrode containing lithium supplement layer, preparation method of negative electrode and lithium battery |
CN114284463A (en) * | 2020-09-27 | 2022-04-05 | 北京好风光储能技术有限公司 | A composite lithium-replenishing sheet and a battery cell and battery provided with the composite lithium-replenishing sheet |
-
2022
- 2022-12-21 CN CN202211651828.4A patent/CN115939308A/en active Pending
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102082288A (en) * | 2009-11-30 | 2011-06-01 | 比亚迪股份有限公司 | Lithium ion secondary battery and manufacture method thereof |
CN109616612A (en) * | 2018-12-05 | 2019-04-12 | 珠海格力电器股份有限公司 | Electrode and lithium ion battery |
CN113823849A (en) * | 2020-06-19 | 2021-12-21 | 比亚迪股份有限公司 | Lithium ion battery and lithium supplement positive plate thereof |
CN114284463A (en) * | 2020-09-27 | 2022-04-05 | 北京好风光储能技术有限公司 | A composite lithium-replenishing sheet and a battery cell and battery provided with the composite lithium-replenishing sheet |
CN114175303A (en) * | 2021-03-26 | 2022-03-11 | 宁德新能源科技有限公司 | Positive pole piece, electrochemical device comprising positive pole piece and electronic device |
CN114267822A (en) * | 2021-11-25 | 2022-04-01 | 东莞市加伏新材料研究院有限公司 | Negative electrode containing lithium supplement layer, preparation method of negative electrode and lithium battery |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN116344979A (en) * | 2023-05-29 | 2023-06-27 | 江苏正力新能电池技术有限公司 | Positive electrode plate and preparation method and application thereof |
CN116344979B (en) * | 2023-05-29 | 2023-08-11 | 江苏正力新能电池技术有限公司 | Positive electrode plate and preparation method and application thereof |
WO2024250640A1 (en) * | 2023-06-08 | 2024-12-12 | 宁德时代新能源科技股份有限公司 | Positive electrode sheet and preparation method therefor, secondary battery, and electric device |
WO2025000951A1 (en) * | 2023-06-25 | 2025-01-02 | 宁德时代新能源科技股份有限公司 | Positive electrode sheet, battery cell, battery, and electric device |
CN116705981A (en) * | 2023-07-27 | 2023-09-05 | 宁德时代新能源科技股份有限公司 | Negative electrode plate, preparation method thereof, battery and electric equipment |
CN116705981B (en) * | 2023-07-27 | 2024-05-03 | 宁德时代新能源科技股份有限公司 | Negative electrode plate, preparation method thereof, battery and electric equipment |
WO2025051253A1 (en) * | 2023-09-07 | 2025-03-13 | 湖北亿纬动力有限公司 | Battery cell and preparation method therefor, and lithium battery comprising battery cell |
WO2024212653A1 (en) * | 2023-12-22 | 2024-10-17 | 湖北亿纬动力有限公司 | Composite electrode sheet and preparation method therefor, and lithium-ion battery |
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