WO2023103993A1

WO2023103993A1 - Electrode sheet and battery

Info

Publication number: WO2023103993A1
Application number: PCT/CN2022/136695
Authority: WO
Inventors: 彭宁
Original assignee: 珠海冠宇电池股份有限公司
Priority date: 2021-12-06
Filing date: 2022-12-05
Publication date: 2023-06-15
Also published as: CN216354301U

Abstract

The present application provides an electrode sheet and a battery. The electrode sheet comprises an electrode sheet body and a tab. The electrode sheet body comprises a current collector, a first active material layer and a second active material layer. The first active material layer and the second active material layer are respectively arranged on two opposite side surfaces of the current collector. A recess is formed on the first active material layer. The bottom wall of the recess is the current collector. The tab is arranged in the recess, and is connected to the current collector by soldering to form a solder joint group. The solder joint group comprises a first solder joint and a second solder joint, the first solder joint is located on the tab, the second solder joint is located on the current collector, and the first solder joint is connected to the second solder joint. The electrode sheet provided by the present application is relatively high in strength after soldering, and the reliability of the electrode sheet after soldering is relatively high.

Description

极片及电池Electrode and battery

本申请要求于2021年12月06日提交中国专利局、申请号为202123044013.3、申请名称为“极片及电池”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。This application claims the priority of the Chinese patent application with the application number 202123044013.3 and the application name "pole piece and battery" submitted to the China Patent Office on December 06, 2021, the entire content of which is incorporated in this application by reference.

技术领域technical field

本申请涉及锂电池技术领域，尤其涉及一种极片及电池。The present application relates to the technical field of lithium batteries, in particular to a pole piece and a battery.

背景技术Background technique

锂离子电池具有容量大、能量密度小、体积小、重量轻和绿色环保等优点，已广泛应用于数码电子产品和电动汽车等行业中。Lithium-ion batteries have the advantages of large capacity, low energy density, small volume, light weight and environmental protection, and have been widely used in digital electronic products and electric vehicles and other industries.

锂离子电池包括正极片、负极片和隔膜。通常在正极片上焊接有正极耳，负极片上焊接有负极耳，正极耳和负极耳用于与外部电路电连接，以对锂离子电池进行充电或放电。A lithium-ion battery includes a positive electrode, a negative electrode, and a separator. Usually, a positive electrode ear is welded on the positive electrode sheet, and a negative electrode ear is welded on the negative electrode sheet. The positive electrode ear and the negative electrode ear are used for electrical connection with an external circuit to charge or discharge the lithium-ion battery.

但是，现有技术中极耳与极片之间的焊接强度低，导致焊接后极片的可靠性较低。However, in the prior art, the welding strength between the tab and the pole piece is low, resulting in low reliability of the welded pole piece.

发明内容Contents of the invention

本申请提供一种极片及电池，以解决现有技术中的极耳与极片之间的焊接强度低，导致极耳焊接后极片的可靠性较低的问题。The present application provides a pole piece and a battery to solve the problem in the prior art that the welding strength between the tab and the pole piece is low, resulting in low reliability of the pole piece after the tab is welded.

本申请一种极片，包括极片本体和极耳，极片本体包括集流体、第一活性物质层和第二活性物质层，第一活性物质层和第二活性物质层分别设置在集流体的相对两个侧面；A pole piece of the present application includes a pole piece body and a tab. The pole piece body includes a current collector, a first active material layer, and a second active material layer. The first active material layer and the second active material layer are respectively arranged on the current collector. the opposite sides of the

第一活性物质层上具有凹槽，凹槽的底壁为集流体，极耳设置在凹槽内，且与集流体焊接，以形成焊点组；There is a groove on the first active material layer, the bottom wall of the groove is a current collector, and the tab is arranged in the groove and welded with the current collector to form a solder joint group;

焊点组包括第一焊点和第二焊点，第一焊点位于极耳上，第二焊点位于集流体上，第一焊点与第二焊点连接。The welding point group includes a first welding point and a second welding point, the first welding point is located on the tab, the second welding point is located on the current collector, and the first welding point is connected to the second welding point.

在一种可能的实现方式中，本申请提供的极片，集流体背离凹槽的表面设置有第二活性物质层，凹槽在集流体上的投影位于第二活性物质层在集流体上的投影内。In a possible implementation manner, in the pole piece provided by the present application, the surface of the current collector facing away from the groove is provided with a second active material layer, and the projection of the groove on the current collector is located at the position of the second active material layer on the current collector. inside the projection.

在一种可能的实现方式中，本申请提供的极片，第二焊点在集流体背离极耳的一侧形成凸起。In a possible implementation manner, in the pole piece provided by the present application, the second welding spot forms a protrusion on the side of the current collector away from the tab.

在一种可能的实现方式中，本申请提供的极片，第二活性物质层覆盖凸起。In a possible implementation manner, in the pole piece provided by the present application, the protrusion is covered by the second active material layer.

在一种可能的实现方式中，本申请提供的极片，第二焊点的深度为集流体厚度的50％～100％。In a possible implementation manner, in the pole piece provided by the present application, the depth of the second welding spot is 50% to 100% of the thickness of the current collector.

在一种可能的实现方式中，本申请提供的极片，焊接区域的宽度为极耳宽度的50％～100％，和/或，焊接区域的长度为极耳与集流体重叠部分长度的50％～100％In a possible implementation manner, in the pole piece provided by the present application, the width of the welding area is 50% to 100% of the width of the tab, and/or the length of the welding area is 50% of the length of the overlapping part of the tab and the current collector. %～100%

在一种可能的实现方式中，本申请提供的极片，极耳为正极耳，正极耳的厚度为集流体厚度的5倍～20倍；In a possible implementation manner, for the pole piece provided by the present application, the tab is a positive tab, and the thickness of the positive tab is 5 to 20 times the thickness of the current collector;

和/或，极耳为负极耳，负极耳的厚度为集流体厚度的10倍～40倍。And/or, the tab is a negative tab, and the thickness of the negative tab is 10 to 40 times the thickness of the current collector.

在一种可能的实现方式中，本申请提供的极片，极耳的厚度为0.01mm～0.5mm，和/或，极耳的宽度为1mm～12mm，和/或，极耳的长度为5mm～50mm；In a possible implementation manner, for the pole piece provided in the present application, the thickness of the tab is 0.01 mm to 0.5 mm, and/or the width of the tab is 1 mm to 12 mm, and/or the length of the tab is 5 mm ~50mm;

极耳的厚度大于或等于凹槽的深度。The thickness of the tab is greater than or equal to the depth of the groove.

本申请提供一种电池，包括上述的极片。The present application provides a battery, including the above pole piece.

在一种可能的实现方式中，本申请提供的电池，极片为两个，至少一个极片上具有避让槽，避让槽与另一极片上的凹槽对应设置。In a possible implementation manner, the battery provided in the present application has two pole pieces, at least one pole piece has an avoidance groove, and the escape groove is provided correspondingly to the groove on the other pole piece.

本申请提供一种极片及电池，极片包括极片本体和极耳，极片本体包括集流体、第一活性物质层和第二活性物质层，第一活性物质层和第二活性物质层分别设置在集流体的相对两个侧面；第一活性物质层上具有凹槽，凹槽的底壁为集流体，极耳设置在凹槽内，且与集流体焊接，以形成焊点组；焊点组包括第一焊点和第二焊点，第一焊点位于极耳上，第二焊点位于集流体上，第一焊点与第二焊点连接。通过激光焊接，使极耳上的焊接熔池完全贯穿极耳并形成第一焊点。集流体厚度方向至少部分融化的焊接熔池形成了第二焊点。第一焊点和第二焊点是一体熔融连接，实现了极耳与集流体电连接，有效增强了极耳与集流体的之间的焊接强度，提高极片焊接后的可靠性，并减少了对焊接区域背面活性物质层的影响。解决了现有技术中极耳与极片之间的焊接强度低，导致焊接后极片的可靠性较低的问题。The application provides a pole piece and a battery. The pole piece includes a pole piece body and tabs. The pole piece body includes a current collector, a first active material layer and a second active material layer, and the first active material layer and the second active material layer. respectively arranged on two opposite sides of the current collector; the first active material layer has a groove, the bottom wall of the groove is a current collector, and the tabs are arranged in the groove and welded with the current collector to form a solder joint group; The welding point group includes a first welding point and a second welding point, the first welding point is located on the tab, the second welding point is located on the current collector, and the first welding point is connected to the second welding point. Through laser welding, the welding molten pool on the tab completely penetrates the tab and forms a first welding spot. The solder pool that is at least partially melted in the thickness direction of the current collector forms the second solder joint. The first solder joint and the second solder joint are integrally melted and connected, which realizes the electrical connection between the tab and the current collector, effectively enhances the welding strength between the tab and the current collector, improves the reliability of the pole piece after welding, and reduces the The effect on the active material layer on the backside of the soldered area was investigated. It solves the problem in the prior art that the welding strength between the tab and the pole piece is low, resulting in low reliability of the pole piece after welding.

附图说明Description of drawings

为了更清楚地说明本申请实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作一简单地介绍，显而易见地，下面描述中的附图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他的附图。In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present application. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

图1为本申请提供的极片的结构示意图；Fig. 1 is the structural representation of the pole piece provided by the present application;

图2为图1中A-A处的剖视图；Fig. 2 is the sectional view of A-A place in Fig. 1;

图3为本申请提供的焊接区域的示意图；Fig. 3 is the schematic diagram of the welding area provided by the present application;

图4为本申请提供的极耳与集流体的连接示意图；4 is a schematic diagram of the connection between the tab and the current collector provided by the present application;

图5为本申请提供的极片的另一种结构示意图；Fig. 5 is another schematic structural view of the pole piece provided by the present application;

图6为图5中B-B处的剖视图；Fig. 6 is the sectional view of B-B place in Fig. 5;

图7为本申请提供的电芯的结构示意图；FIG. 7 is a schematic structural view of the cell provided by the present application;

图8为本申请提供的正极片与负极片叠加的示意图。FIG. 8 is a schematic diagram of the stacking of the positive electrode sheet and the negative electrode sheet provided by the present application.

附图标记说明Explanation of reference signs

10-极片；10-pole piece;

11-正极片；11 - Positive plate;

12-负极片；12 - Negative electrode sheet;

20-隔膜；20 - diaphragm;

100-极片本体；100-pole piece body;

110-集流体；110-collector;

111-焊接区域；111 - welding area;

112-焊点组；112-solder spot group;

113-第一焊点；113-the first welding spot;

114-第二焊点；114-the second welding spot;

120a-第一活性物质层；120a - the first active material layer;

120b-第二活性物质层；120b - the second active material layer;

121-凹槽；121 - groove;

122-避让槽；122- avoidance groove;

130-缺口；130 - gap;

200-极耳；200-pole ear;

210-极耳胶；210 - pole ear glue;

310-第一绝缘胶层；310-the first insulating adhesive layer;

320-第二绝缘胶层；320-the second insulating adhesive layer;

D-极耳的宽度；D- the width of the tab;

L-极耳与集流体重叠部分长度；L-the length of the overlapping part of the tab and the current collector;

D1-焊接区域的宽度；D1 - the width of the welding area;

L1-焊接区域的长度；L1 - the length of the welding area;

L10-极片本体长度；L10- pole piece body length;

L11-凹槽距离极片本体一端的距离；L11-the distance between the groove and one end of the pole piece body;

L12-避让槽距离极片本体一端的距离。L12-the distance between the escape groove and one end of the pole piece body.

具体实施方式Detailed ways

为使本申请实施例的目的、技术方案和优点更加清楚，下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.

在本申请的描述中，需要说明的是，除非另有明确的规定和限定，术语“安装”、“相连”、“连接”应作广义理解，例如，可以使固定连接，也可以是通过中间媒介间接相连，可以是两个元件内部的连通或者两个元件的相互作用关系。对于本领域的普通技术人员而言，可以根据具体情况理解上述术语在本申请中的具体含义。In the description of this application, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be fixedly connected, or through an intermediate The media is indirectly connected, which can be the internal communication of two elements or the interaction relationship between two elements. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

在本申请的描述中，需要理解的是，术语“上”、“下”、“前”、“后”、“竖直”、“水平”、“顶”、“底”、“内”、“外”等指示的方位或者位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请和简化描述，而不是指示或者暗示所指的装置或者元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请的限制。In the description of this application, it is to be understood that the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", The orientation or positional relationship indicated by "outside" is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, constructed and operated in a particular orientation and therefore should not be construed as limiting the application.

本申请的说明书和权利要求书及上述附图中的术语“第一”、“第二”、“第三”(如果存在)是用于区别类似的对象，而不必用于描述特定的顺序或先后次序。应该理解这样使用的数据在适当情况下可以互换，以便这里描述的本申请的实施例例如能够以除了在这里图示或描述的那些以外的顺序实施。The terms "first", "second", and "third" (if any) in the description and claims of the present application and the above drawings are used to distinguish similar objects and not necessarily to describe a specific order or priority. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein, for example, can be practiced in sequences other than those illustrated or described herein.

此外，术语“包括”和“具有”以及他们的任何变形，意图在于覆盖不排他的包含，例如，包含了一系列步骤或单元的过程、方法、***、产品或维护工具不必限于清楚地列出的那些步骤或单元，而是可包括没有清楚地列出的或对于这些过程、方法、产品或维护工具固有的其它步骤或单元。Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or maintenance tool comprising a series of steps or units need not be limited to the expressly listed Instead, other steps or elements not explicitly listed or inherent to the process, method, product or maintenance tool may be included.

锂离子电池是一种二次电池(充电电池)，它主要依靠锂离子在正极和负极之间来回移动进行工作。在充/放电过程中，锂离子在正极和负极之间往返嵌入和脱嵌。充电时，锂离子从正极脱嵌，经过电解质嵌入负极，负极处于富锂状态；放电时则相反。作为一种新型储能电池，由于具有高能量、长寿命、低耗能、无公害、无记忆效应以及自放电小、内阻小、性价比高、污染少等优点，锂离子电池逐步在应用中显示出巨大的优势，其广泛应用于移动电话、笔记本电脑、摄像机、数码相机、电动汽车、储能、航天等各领域。Lithium-ion battery is a secondary battery (rechargeable battery), which mainly relies on lithium ions to move back and forth between the positive and negative electrodes to work. During the charge/discharge process, lithium ions intercalate and deintercalate back and forth between the positive and negative electrodes. When charging, lithium ions are deintercalated from the positive electrode, inserted into the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state; the opposite is true when discharging. As a new type of energy storage battery, due to its advantages of high energy, long life, low energy consumption, pollution-free, no memory effect, small self-discharge, low internal resistance, high cost performance, and less pollution, lithium-ion batteries are gradually being used in applications. It shows great advantages, and it is widely used in various fields such as mobile phones, notebook computers, video cameras, digital cameras, electric vehicles, energy storage, and aerospace.

锂离子电池主要包括壳体、极片和隔膜，极片包括正极片和负极片，隔膜设置在正极片和负极之间，并与正/负极片一起卷绕形成电芯。在电芯外边加装壳体后就组成锂离子电池。其中，在极片上连接有极耳，极耳用于与外部电路连接以对电池进行充电或者放电。极耳包括设置在正极片上的正极耳和设置在负极片上的负极耳。由于极耳是采用易于导电的金属材料制成的，因此为了提高极耳与极片之间电流的导通能力，通常采用焊接的方式将焊接在极片上，以使极耳与极片之间电性连接。但是，现有技术中极耳与极片之间的焊接强度低，导致焊接后极片的可靠性较低。A lithium-ion battery mainly includes a casing, a pole piece and a separator. The pole piece includes a positive pole piece and a negative pole piece. The separator is arranged between the positive pole piece and the negative pole piece, and is wound together with the positive pole piece and the negative pole piece to form a battery core. A lithium-ion battery is formed after a casing is installed outside the battery cell. Wherein, a tab is connected to the pole piece, and the tab is used for connecting with an external circuit to charge or discharge the battery. The tabs include positive tabs arranged on the positive sheet and negative tabs arranged on the negative sheet. Since the tabs are made of metal materials that are easy to conduct electricity, in order to improve the conduction capacity of the current between the tabs and the pole pieces, welding is usually used to weld them on the pole pieces so that the gap between the tabs and the pole pieces electrical connection. However, in the prior art, the welding strength between the tab and the pole piece is low, resulting in low reliability of the welded pole piece.

基于此，本申请提供一种极片及电池，通过增强焊接后极耳与极片之间的焊接强度，以提高极耳焊接后极片的可靠性。Based on this, the present application provides a pole piece and a battery. By enhancing the welding strength between the pole piece and the pole piece after welding, the reliability of the pole piece after welding the pole piece is improved.

实施例Example

图1为本申请提供的极片的结构示意图，图2为图1中A-A处的剖视图，图3为本申请提供的焊接区域的示意图，图4为本申请提供的极耳与集流体的连接示意图。如图1和图2所示，本申请提供一种极片10，包括极片本体100和极耳200，极片本体100包括集流体110、第一活性物质层120a和第二活性物质层120b，第一活性物质层120a和第二活性物质层120b分别设置在集流体110的相对两个侧面。Figure 1 is a schematic structural view of the pole piece provided by the application, Figure 2 is a cross-sectional view at A-A in Figure 1, Figure 3 is a schematic diagram of the welding area provided by the application, and Figure 4 is the connection between the tab and the current collector provided by the application schematic diagram. As shown in Figures 1 and 2, the present application provides a pole piece 10, including a pole piece body 100 and a tab 200, and the pole piece body 100 includes a current collector 110, a first active material layer 120a, and a second active material layer 120b , the first active material layer 120 a and the second active material layer 120 b are respectively disposed on two opposite sides of the current collector 110 .

如图3所示，第一活性物质层120a上具有凹槽121，凹槽121的底壁为集流体110，极耳200设置在凹槽121内，且与集流体110焊接，以形成焊点组112。As shown in FIG. 3 , there is a groove 121 on the first active material layer 120a, the bottom wall of the groove 121 is the current collector 110, and the tab 200 is arranged in the groove 121 and welded with the current collector 110 to form a solder joint. Group 112.

如图4所示，焊点组112包括第一焊点113和第二焊点114，第一焊点113位于极耳200上，第二焊点114位于集流体110上，第一焊点113和第二焊点114连接。As shown in FIG. 4 , the welding point group 112 includes a first welding point 113 and a second welding point 114, the first welding point 113 is located on the tab 200, the second welding point 114 is located on the current collector 110, and the first welding point 113 It is connected with the second pad 114.

在本实施例中，极片10为设置在电池内部，用于充放电的部件。极片10包括极片本体100和极耳200，极片本体100包括集流体110、第一活性物质层120a和第二活性物质层120b，第一活性物质层120a和第二活性物质层120b分别设置在集流体110的相对两个侧面上以形成层状叠加的极片本体100。In this embodiment, the pole piece 10 is a component arranged inside the battery for charging and discharging. The pole piece 10 includes a pole piece body 100 and a pole piece 200. The pole piece body 100 includes a current collector 110, a first active material layer 120a, and a second active material layer 120b. The first active material layer 120a and the second active material layer 120b are respectively The pole piece body 100 is arranged on two opposite sides of the current collector 110 to form a laminated stack.

极片10上的集流体110由金属材料制作，通常选用铝(Al)、镍(Ni)、铜(Cu)或铜镀镍(Ni—Cu)合金等材料制作而成。第一活性物质层120a和第二活性物质层120b则由活性物质、导电剂和粘接剂等材料组合而成。第一活性物质层120a和第二活性物质层120b分别涂覆在集流体110的相对两个侧面上后就形成极片本体100。The current collector 110 on the pole piece 10 is made of metal material, usually aluminum (Al), nickel (Ni), copper (Cu) or nickel-plated copper (Ni—Cu) alloy. The first active material layer 120a and the second active material layer 120b are composed of materials such as active materials, conductive agents, and adhesives. After the first active material layer 120 a and the second active material layer 120 b are respectively coated on two opposite side surfaces of the current collector 110 , the pole piece body 100 is formed.

为了便于焊接极耳200，在极片本体100的其中一个侧面的第一活性物质层120a上设置有凹槽121。具体而言就是通过采用激光清洗、发泡或机械等技术将第一活性物质层120a表面的特定区域内涂覆的活性物质进行刮除，以使在该区域处第一活性物质层120a覆盖的集流体110表面漏出，以进行焊接极耳200。In order to facilitate the welding of the tab 200 , a groove 121 is provided on the first active material layer 120 a on one side of the pole piece body 100 . Specifically, the active material coated in a specific area on the surface of the first active material layer 120a is scraped off by laser cleaning, foaming or mechanical techniques, so that the area covered by the first active material layer 120a The surface of the current collector 110 leaks out to weld the tab 200 .

请继续参见图1所示，凹槽121位于极片本体100的中部区域，凹槽121距离极片本体100一端的距离为极片本体100总长度的1/3～2/3。具体地，极片本体100的长度为L10，凹槽121距离极片本体100一端的距离为L11，则L11为L10的1/3～2/3。凹槽121的宽度尺寸范围为2mm～30mm，长度尺寸范围为2mm～40mm，深度尺寸范围为0.01mm～1mm。Please continue to refer to FIG. 1 , the groove 121 is located in the middle region of the pole piece body 100 , and the distance from the groove 121 to one end of the pole piece body 100 is 1/3˜2/3 of the total length of the pole piece body 100 . Specifically, the length of the pole piece body 100 is L10, the distance between the groove 121 and one end of the pole piece body 100 is L11, and L11 is 1/3˜2/3 of L10. The groove 121 has a width ranging from 2 mm to 30 mm, a length ranging from 2 mm to 40 mm, and a depth ranging from 0.01 mm to 1 mm.

极耳200为从电池中将正、负电极引出来的金属导电体，即电池正、负电极对应的极耳200是在进行充/放电时的接触点。这个接触点并不是通常看到的电池外表的那个铜片，而是设置在电池内部的用于极片与保护电路电连接的部件。极耳200主要由三种材料形成，通常选用铝(Al)材料、镍(Ni)、铜(Cu)或铜镀镍(Ni—Cu)合金等材料，它们都是由胶片和金属带两部分复合而成。The tabs 200 are metal conductors that lead the positive and negative electrodes out of the battery, that is, the tabs 200 corresponding to the positive and negative electrodes of the battery are contact points during charging/discharging. This contact point is not the copper sheet that is usually seen on the outside of the battery, but a component inside the battery that is used to electrically connect the pole piece to the protection circuit. The tab 200 is mainly formed of three materials, usually aluminum (Al), nickel (Ni), copper (Cu) or copper nickel-plated (Ni-Cu) alloy, etc., which are made of two parts: film and metal strip. Composite.

请继续参见图1所示，为了去除凹槽121边缘的毛刺和残留的活性物质层120，避免毛刺和活性物质层120影响极耳200的焊接效果，本申请中在凹槽121的边缘还设置有缺口130，缺口130的宽度尺寸为凹槽121宽度的50％～100％，缺口130的长度尺寸为凹槽121长度的1％～50％。Please continue to refer to FIG. 1, in order to remove the burrs and residual active material layer 120 on the edge of the groove 121, and avoid the burrs and the active material layer 120 from affecting the welding effect of the tab 200, in the present application, the edge of the groove 121 is also set There is a notch 130 , the width of the notch 130 is 50%-100% of the width of the groove 121 , and the length of the notch 130 is 1%-50% of the length of the groove 121 .

请继续参见图1和图3所示，在极片本体100上凹槽121内的集流体110表面设置有焊接区域111，且焊接区域111与凹槽121连通，极耳200通过焊点组112焊接在焊接区域111上。Please continue to refer to FIG. 1 and FIG. 3, the surface of the current collector 110 in the groove 121 on the pole piece body 100 is provided with a welding area 111, and the welding area 111 communicates with the groove 121, and the tab 200 passes through the welding point group 112 Welded on the welding area 111.

如图3和图4所示，焊点组112包括多个第一焊点113和第二焊点114，第一焊点113位于极耳200上，且第一焊点113通过极耳200焊接熔池形成，第一焊点113贯穿极耳200。第二焊点114位于集流体110上，且第二焊点114通过极耳200和集流体110焊接熔池形成，第二焊点114的深度为集流体110厚度的50％～100％。这样可以使极耳200与集流体110电连接，电流可以经极耳200在极片本体100和外部电路之间来回流动。As shown in FIGS. 3 and 4 , the solder joint group 112 includes a plurality of first solder joints 113 and second solder joints 114 , the first solder joints 113 are located on the tab 200 , and the first solder joints 113 are welded through the tab 200 A molten pool is formed, and the first welding spot 113 runs through the tab 200 . The second welding point 114 is located on the current collector 110 , and the second welding point 114 is formed by welding the tab 200 and the current collector 110 . The depth of the second welding point 114 is 50%-100% of the thickness of the current collector 110 . In this way, the tab 200 can be electrically connected to the current collector 110 , and current can flow back and forth between the tab body 100 and the external circuit through the tab 200 .

在一些实施例中，通过采用激光焊接的方式将极耳200焊接在集流体110上。具体地，首先在集流体110的相对两侧表面涂覆第一活性物质层120a和第二活性物质层120b，并在集流体110的其中一侧表面上的第一活性物质层120a上设置凹槽121，在凹槽121内裸露的集流体110表面形成焊接区域111，集流体110上与焊接区域111相对的另外一侧表面带有第二活性物质层120b，凹槽121在集流体110上的投影位于第二活性物质层120b在集流体110上的投影内。集流体110和第二活性物质层120b共同做为底层。将极耳200放置在集流体110的上方，通过夹具(图中未标示)等工装将极耳200固定在凹槽121内，并使极耳200与集流体110之间处于压紧状态。设置激光器(图中未标示)的脉宽小于等于1ms，设置焊接时间小于等于5秒，设置焊接的轨迹(包括但不限于螺旋点、正弦线、圆点、字符等)，激光光束通过夹具打击在极耳200上背离集流体110一侧的表面，并在该表面形成特定焊接轨迹的形貌。而背离极耳200的另外一侧表面的第二活性物质层120b则未受到任何影响。In some embodiments, the tab 200 is welded on the current collector 110 by laser welding. Specifically, firstly, the first active material layer 120a and the second active material layer 120b are coated on the opposite two sides of the current collector 110, and concave holes are provided on the first active material layer 120a on one side surface of the current collector 110. Groove 121, the exposed current collector 110 surface in the groove 121 forms a welding area 111, and the other side surface of the current collector 110 opposite to the welding area 111 has a second active material layer 120b, and the groove 121 is on the current collector 110 The projection of is located within the projection of the second active material layer 120b on the current collector 110 . The current collector 110 and the second active material layer 120b together serve as a bottom layer. The tab 200 is placed above the current collector 110 , and the tab 200 is fixed in the groove 121 by fixtures (not shown in the figure) and other tooling, and the tab 200 and the current collector 110 are in a compressed state. Set the pulse width of the laser (not shown in the figure) to be less than or equal to 1ms, set the welding time to be less than or equal to 5 seconds, set the trajectory of welding (including but not limited to spiral points, sinusoidal lines, dots, characters, etc.), and the laser beam hits through the fixture On the surface of the tab 200 away from the current collector 110 , a specific welding track is formed on the surface. However, the second active material layer 120b on the surface of the other side away from the tab 200 is not affected in any way.

当激光焊接完成后，极耳200被完全贯穿，极耳200上的焊接熔池形成了第一焊点113。集流体110厚度方向至少部分融化形成焊接熔池，集流体110上的焊接熔池形成了第二焊点114，第二焊点114的深度为集流体厚度的50％～100％。第二焊点114在可以在背离集流体110的一侧表面形成凸起(图中未标示)，第二活性物质层120b可以覆盖在凸起上。第一焊点113和第二焊点114是一体熔融连接的，以使极耳200与集流体110电连接。这样设置的优点在于可以有效增强极耳200与集流体110的之间的焊接强度，提高极片10焊接后的可靠性，并减少了对焊接区域111背面第二活性物质层120b的影响。After the laser welding is completed, the tab 200 is completely penetrated, and the weld pool on the tab 200 forms the first welding spot 113 . The thickness direction of the current collector 110 is at least partially melted to form a molten weld pool, and the molten weld pool on the current collector 110 forms a second welding point 114, and the depth of the second welding point 114 is 50%-100% of the thickness of the current collector. The second solder joint 114 may form a protrusion (not shown in the figure) on the side away from the current collector 110 , and the second active material layer 120b may cover the protrusion. The first welding point 113 and the second welding point 114 are integrally melted and connected, so that the tab 200 is electrically connected to the current collector 110 . The advantage of this arrangement is that it can effectively enhance the welding strength between the tab 200 and the current collector 110 , improve the reliability of the pole piece 10 after welding, and reduce the impact on the second active material layer 120b on the back of the welding area 111 .

在本申请中，可以通过将焊点组112嵌入水晶胶中，待水晶胶凝固后，通过砂纸研磨抛光，并用浓度为0.5％的氢氟酸溶液，或是浓度为25％的硝酸溶液，或是10％～20％的硫酸进行腐蚀，通过显微镜观察测量焊点组112的熔深的尺寸。In this application, the solder joint group 112 can be embedded in the crystal glue, after the crystal glue is solidified, it is ground and polished by sandpaper, and the concentration is 0.5% hydrofluoric acid solution, or the concentration is 25% nitric acid solution, or Corrosion is performed with 10% to 20% sulfuric acid, and the size of the penetration depth of the solder joint group 112 is measured through microscope observation.

请继续参见图1和图3所示，将极耳200焊接在集流体110上之后，极耳200的一部分结构位于凹槽121内且与集流体110重叠，极耳200的另外一部分结构则位于凹槽121的外部。而为了提高极耳200与极片本体100上的集流体110在焊接后的可靠性，本实施例中通过增大焊接区域111的面积大小来提高极耳200的焊接后的可靠性。具体而言就是将焊接区域111的宽度设置为极耳200宽度的50％～100％，将焊接区域111的长度设置为极耳200上与集流体110重叠部分长度的50％～100％。其中，极耳200的宽度为D，极耳200与集流体110重叠部分的长度为L，则焊接区域111的宽度D1为D的0.5倍～1倍，焊接区域111的长度L1为L的0.5倍～1倍。Please continue to refer to FIG. 1 and FIG. 3, after the tab 200 is welded on the current collector 110, a part of the structure of the tab 200 is located in the groove 121 and overlaps with the current collector 110, and the other part of the structure of the tab 200 is located outside of the groove 121. In order to improve the reliability of the tab 200 and the current collector 110 on the pole piece body 100 after welding, in this embodiment, the reliability of the tab 200 after welding is improved by increasing the size of the welding region 111 . Specifically, the width of the welding area 111 is set to 50%-100% of the width of the tab 200 , and the length of the welding area 111 is set to 50%-100% of the length of the overlapping part of the tab 200 with the current collector 110 . Wherein, the width of the tab 200 is D, and the length of the overlapping part of the tab 200 and the current collector 110 is L, the width D1 of the welding area 111 is 0.5 times to 1 time of D, and the length L1 of the welding area 111 is 0.5 times of L. Times ~ 1 times.

请继续参见图1和图2所示，极耳200为正极耳(图中未标示)，正极耳的厚度为集流体110厚度的5倍～20倍；和/或，极耳200为负极耳(图中未标示)，负极耳的厚度为集流体110厚度的10倍～40倍。Please continue to refer to FIG. 1 and FIG. 2, the tab 200 is a positive tab (not shown in the figure), and the thickness of the positive tab is 5 to 20 times the thickness of the current collector 110; and/or, the tab 200 is a negative tab (not shown in the figure), the thickness of the negative tab is 10 to 40 times the thickness of the current collector 110 .

在本实施例中，极耳200分为正极耳和负极耳，正极耳和负极耳分别与不同的极片本体100焊接。为了提高极耳200与集流体110焊接后的强度，本申请中将极耳200的厚度设置在一个适当的范围内，这样不但可以增加极耳200和集流体110的焊接强度，还会避免极耳200厚度过大导致电池的厚度发生改变。具体地，当极耳200为正极耳时，其厚度为集流体110厚度的5倍～20倍；当极耳200为负极耳时，其厚度为集流体110厚度的10倍～40倍。这样设置的目的在于可以有效提高极耳200与集流体110焊接的可靠性，保证极耳200上通过电流的能力。In this embodiment, the tab 200 is divided into a positive tab and a negative tab, and the positive tab and the negative tab are respectively welded to different pole piece bodies 100 . In order to improve the strength of the tab 200 and the current collector 110 after welding, the thickness of the tab 200 is set in an appropriate range in this application, which can not only increase the welding strength of the tab 200 and the current collector 110, but also avoid the The thickness of the ear 200 is too large to change the thickness of the battery. Specifically, when the tab 200 is a positive tab, its thickness is 5 to 20 times the thickness of the current collector 110 ; when the tab 200 is a negative tab, its thickness is 10 to 40 times the thickness of the current collector 110 . The purpose of such arrangement is to effectively improve the reliability of the welding between the tab 200 and the current collector 110 , and ensure the ability of the tab 200 to pass current.

请继续参见图1和图2所示，极耳200的厚度为0.01mm～0.5mm，和/或，极耳200的宽度为1mm～12mm，和/或，极耳200的长度为5mm～50mm。Please continue to refer to FIG. 1 and FIG. 2, the thickness of the tab 200 is 0.01 mm to 0.5 mm, and/or the width of the tab 200 is 1 mm to 12 mm, and/or the length of the tab 200 is 5 mm to 50 mm .

在一些实施例中，为了提高极耳200的导电能力，通常将极耳200的尺寸设置的相对较大一点。一般地，极耳200厚度的尺寸范围为0.01mm～0.5mm，极耳200宽度的尺寸范围为1mm～12mm，极耳200长度的尺寸范围为5mm～50mm。In some embodiments, in order to improve the electrical conductivity of the tab 200 , the size of the tab 200 is generally set relatively larger. Generally, the thickness of the tab 200 ranges from 0.01 mm to 0.5 mm, the width of the tab 200 ranges from 1 mm to 12 mm, and the length of the tab 200 ranges from 5 mm to 50 mm.

在本实施例中，为了保证极耳200的导电能力以及避免极耳200被焊穿，极耳200的厚度大于或等于凹槽121的深度。因为在合理的尺寸范围之内，极耳200的厚度与导电能力是成正比关系的，即极耳200的厚度越大，其导电能力越强。同时，极耳200厚度增大后也可以有效避免极耳200在焊接时被焊穿，提高了焊接良率。In this embodiment, in order to ensure the electrical conductivity of the tab 200 and prevent the tab 200 from being welded through, the thickness of the tab 200 is greater than or equal to the depth of the groove 121 . Because within a reasonable size range, the thickness of the tab 200 is directly proportional to the conductivity, that is, the thicker the tab 200 is, the stronger its conductivity is. At the same time, the increased thickness of the tab 200 can effectively prevent the tab 200 from being welded through during welding, thereby improving the welding yield.

请继续参见图1和图3所示，在极耳200上还设置有极耳胶210，极耳胶210是粘接在极耳200的相对两个侧面用于对极耳200进行绝缘密封，防止极耳200出现短路现象。Please continue to refer to FIG. 1 and FIG. 3 , there is also a tab glue 210 on the tab 200, and the tab glue 210 is bonded to two opposite sides of the tab 200 for insulating and sealing the tab 200, Prevent the short circuit phenomenon of the tab 200 .

图5为本申请提供的极片的另一结构示意图，图6为图5中B-B处的剖视图。如图5和图6所示，本申请还提供了另一种极片10结构，在极片本体100上第一活性物质层120a上具有避让槽122，避让槽122与凹槽121位于第一活性物质层120a的同一侧面。FIG. 5 is another schematic structural view of the pole piece provided by the present application, and FIG. 6 is a cross-sectional view at B-B in FIG. 5 . As shown in Fig. 5 and Fig. 6, the present application also provides another pole piece 10 structure, in which there is an escape groove 122 on the first active material layer 120a on the pole piece body 100, and the escape groove 122 and the groove 121 are located at the first The same side of the active material layer 120a.

在一种可能的实现方式中，为了降低极片10卷绕形成的电芯的厚度，本申请提供了另一种极片10，在极片本体100上的第一活性物质层120a上设置有避让槽122，且避让凹槽122和凹槽121位于极片本体100的同一个侧面，避让槽122设置在第一活性物质层120a上，凹槽121和避让槽122的大小尺寸一致。避让槽122也是通过采用激光清洗、发泡或机械等技术将第一活性物质层120a表面的特定区域内涂覆的活性物质进行刮除。In a possible implementation manner, in order to reduce the thickness of the battery core formed by winding the pole piece 10, the present application provides another pole piece 10, and the first active material layer 120a on the pole piece body 100 is provided with The avoidance groove 122, and the avoidance groove 122 and the groove 121 are located on the same side of the pole piece body 100, the avoidance groove 122 is arranged on the first active material layer 120a, and the size of the avoidance groove 121 and the avoidance groove 122 are consistent. The escape groove 122 is also scraped off the active material coated in a specific area on the surface of the first active material layer 120a by adopting laser cleaning, foaming or mechanical techniques.

具体地，避让槽122位于极片本体100的中部区域，避让槽122距离极片本体100一端的距离为极片本体100总长度的1/3～2/3。避让槽122距离极片本体100一端的距离为L12，则L12为L10的1/3～2/3。避让槽122的宽度尺寸范围为2mm～30mm，长度尺寸范围为2mm～40mm，深度尺寸范围为0.01mm～1mm。Specifically, the escape groove 122 is located in the middle region of the pole piece body 100 , and the distance from the avoidance groove 122 to one end of the pole piece body 100 is 1/3˜2/3 of the total length of the pole piece body 100 . The distance between the escape groove 122 and one end of the pole piece body 100 is L12, and then L12 is 1/3-2/3 of L10. The width of the escape groove 122 ranges from 2 mm to 30 mm, the range of length from 2 mm to 40 mm, and the range of depth from 0.01 mm to 1 mm.

请继续参见图5和图6所示，为了提高极耳200焊接后在焊接位置处的绝缘性能，本申请中在凹槽121的表面贴附有第一绝缘胶层310，第一绝缘胶层310的厚度尺寸范围为0.001mm～0.1mm，其长度尺寸/宽度尺寸分别大于凹槽121的长度尺寸/宽度尺寸。这样设置的目的在于，第一绝缘胶层310可以将焊接区域111、部分极耳200以及整个凹槽121完全覆盖，这样设置可以使凹槽121内部的极耳200和集流体110完全被密封绝缘，避免出现短路的风险。Please continue to refer to Figures 5 and 6, in order to improve the insulation performance of the tab 200 at the welding position after welding, in this application, a first insulating adhesive layer 310 is attached to the surface of the groove 121, the first insulating adhesive layer The thickness of the 310 ranges from 0.001 mm to 0.1 mm, and its length/width are larger than the length/width of the groove 121 . The purpose of this setting is that the first insulating adhesive layer 310 can completely cover the welding area 111, part of the tab 200 and the entire groove 121, so that the tab 200 and the current collector 110 inside the groove 121 can be completely sealed and insulated. , to avoid the risk of short circuits.

图7为本申请提供的电芯的结构示意图。如图7所示，本申请提供一种电芯结构，包括卷绕设置的正极片11、负极片12和隔膜20，隔膜20位于正极片11和负极片12之间，正极片11和/或负极片12为上述内容中的极片10。FIG. 7 is a schematic structural view of the battery cell provided by the present application. As shown in FIG. 7 , the present application provides a cell structure, including a wound positive electrode sheet 11, a negative electrode sheet 12, and a separator 20. The separator 20 is located between the positive electrode sheet 11 and the negative electrode sheet 12. The positive electrode sheet 11 and/or The negative electrode sheet 12 is the above-mentioned electrode sheet 10 .

本申请提供一种电池，包括壳体上述内容中的极片10。极片10为两个，两个极片10可以分别为正极片11和负极片12。至少一个极片10上具有避让槽122，避让槽122与另一极片10上的凹槽121对应设置。The present application provides a battery, including the pole piece 10 described above in the casing. There are two pole pieces 10, and the two pole pieces 10 can be positive pole piece 11 and negative pole piece 12 respectively. At least one pole piece 10 has an escape groove 122 corresponding to the groove 121 on the other pole piece 10 .

具体地，正极片11可以为图1所示的极片10或图5所示的另一种极片10，负极片12可以为图1所示的极片10或图5所示的另一种极片10，本申请对此不做具体限定。以下选择正极片11为图1所示的极片10，负极片为图5所示的极片10进行解释说明。Specifically, the positive pole piece 11 can be the pole piece 10 shown in FIG. 1 or another kind of pole piece 10 shown in FIG. 5, and the negative pole piece 12 can be the pole piece 10 shown in FIG. 1 or another pole piece 10 shown in FIG. The seed pole piece 10 is not specifically limited in this application. In the following, the positive electrode sheet 11 is selected as the electrode sheet 10 shown in FIG. 1 , and the negative electrode sheet is selected as the electrode sheet 10 shown in FIG. 5 for explanation.

如图1、图2和图6所示，正极片11的极片本体100包括集流体110和活性物质层120，其中集流体110选用铝(Al)材料制作而成，第一活性物质层120a和第二活性物质层120b的组成材料通常包括正极活性物质、粘接剂和导电剂，正极活性物质主要包括钴酸锂(LCO)、镍钴锰三元材料(NCM)、镍钴铝三元材料(NCA)、镍钴锰铝四元材料(NCMA)、磷酸铁锂(LFP)、磷酸锰锂(LMP)、磷酸钒锂(LVP)、锰酸锂(LMO)、富锂锰基中的至少一种。As shown in Fig. 1, Fig. 2 and Fig. 6, the pole piece body 100 of the positive pole piece 11 comprises a current collector 110 and an active material layer 120, wherein the current collector 110 is made of aluminum (Al) material, and the first active material layer 120a The composition materials of the second active material layer 120b generally include a positive electrode active material, a binder and a conductive agent, and the positive electrode active material mainly includes lithium cobalt oxide (LCO), nickel-cobalt-manganese ternary material (NCM), nickel-cobalt-aluminum ternary material Materials (NCA), nickel-cobalt-manganese-aluminum quaternary material (NCMA), lithium iron phosphate (LFP), lithium manganese phosphate (LMP), lithium vanadium phosphate (LVP), lithium manganese oxide (LMO), lithium-rich manganese at least one.

在正极片11的极片本体100上焊接的极耳200为正极耳，正极耳的材质也是选用铝(Al)材料，正极耳通过激光焊接的方式焊接在正极片11上的凹槽121内的焊接区域111上。在焊接完成后的正极耳表面上贴附有第一绝缘胶层310，第一绝缘胶层310将正极耳的部分表面和凹槽121完全覆盖。在正极耳与外部电路电连接后就可以形成电池的正极。The pole lug 200 welded on the pole piece body 100 of the positive pole piece 11 is a positive pole piece, and the material of the positive pole piece is also aluminum (Al) material, and the positive pole piece is welded in the groove 121 on the positive pole piece 11 by laser welding. on the welding area 111. A first insulating adhesive layer 310 is pasted on the surface of the positive tab after welding, and the first insulating adhesive layer 310 completely covers part of the surface of the positive tab and the groove 121 . The positive pole of the battery can be formed after the positive tab is electrically connected to the external circuit.

如图5和图6所示，负极片12的极片本体100包括集流体110和活性物质层120，其中集流体110选用镍(Ni)、铜(Cu)或铜镀镍(Ni—Cu)合金等材料制作而成，第一活性物质层120a和第二活性物质层120b的组成材料通常包括负极活性物质、粘接剂和导电剂，负极活性物质包括石墨、中间相碳微球、软碳、硬碳、硅材料、硅氧材料、硅碳材料、钛酸锂中的至少一种。As shown in Figures 5 and 6, the pole piece body 100 of the negative electrode piece 12 includes a current collector 110 and an active material layer 120, wherein the current collector 110 is selected from nickel (Ni), copper (Cu) or nickel-plated copper (Ni—Cu) Alloy and other materials, the composition of the first active material layer 120a and the second active material layer 120b usually include negative electrode active material, binder and conductive agent, the negative electrode active material includes graphite, mesocarbon microspheres, soft carbon , hard carbon, silicon material, silicon oxygen material, silicon carbon material, lithium titanate at least one.

在负极片12的极片本体100上焊接的极耳200为负极耳，负极耳的材质也是选用镍(Ni)、铜(Cu)或铜镀镍(Ni—Cu)合金等材料，负极耳通过激光焊接的方式焊接在负极片12上的凹槽121内的焊接区域111上。在焊接完成后的负极耳表面上贴附有第一绝缘胶层310，第一绝缘胶层310将负极耳的部分表面和凹槽121完全覆盖。在负极耳与外部电路电连接后就可以形成电池的负极。The pole lug 200 welded on the pole piece body 100 of the negative pole piece 12 is a negative pole lug, and the material of the negative pole lug is also selected materials such as nickel (Ni), copper (Cu) or copper-plated nickel (Ni—Cu) alloy, and the negative pole lug passes through Laser welding is performed on the welding area 111 in the groove 121 on the negative electrode sheet 12 . A first insulating adhesive layer 310 is pasted on the surface of the negative tab after welding, and the first insulating adhesive layer 310 completely covers part of the surface of the negative tab and the groove 121 . The negative pole of the battery can be formed after the negative pole ear is electrically connected with the external circuit.

另外，在负极片12的极片本体100上还设置有避让槽122，负极片12上的避让槽122与凹槽121均位于极片本体100的同一个侧面上，且避让槽122设置在第一活性物质层120a上。在避让槽122的表面覆盖有第二绝缘胶层320，且第二绝缘胶层320的尺寸大于避让槽122的尺寸，这样设置可以确保第二绝缘胶层320将避让槽122完全覆盖。In addition, an avoidance groove 122 is also provided on the pole piece body 100 of the negative pole piece 12, and the escape groove 122 and the groove 121 on the negative pole piece 12 are all located on the same side of the pole piece body 100, and the escape groove 122 is arranged on the second an active material layer 120a. The surface of the escape groove 122 is covered with a second insulating glue layer 320 , and the size of the second insulating glue layer 320 is larger than that of the escape groove 122 , so that the second insulating glue layer 320 can completely cover the escape groove 122 .

图8为本申请提供的正极片与负极片叠加的示意图。如图7和图8所示，当正极片11和负极片12与隔膜一起卷绕形成电芯时，正极片11上极耳200的焊接部分与负极片12上的避让槽122相对应，也就是说负极片12上的避让槽122与正极片11上的第一绝缘胶层310的位置相互对应。在进行卷绕时，正极片11上的部分第一绝缘胶层310和负极片12上的避让槽122所对应的部分隔膜20可以容置在避让槽122内部，这样可以有效避免第一绝缘胶层310和第二绝缘胶层320在叠加后使电芯的整体厚度增大。FIG. 8 is a schematic diagram of the stacking of the positive electrode sheet and the negative electrode sheet provided by the present application. As shown in Figures 7 and 8, when the positive electrode sheet 11 and the negative electrode sheet 12 are wound together with the separator to form a cell, the welding part of the tab 200 on the positive electrode sheet 11 corresponds to the escape groove 122 on the negative electrode sheet 12, and also That is to say, the escape groove 122 on the negative electrode sheet 12 corresponds to the position of the first insulating adhesive layer 310 on the positive electrode sheet 11 . During winding, part of the first insulating adhesive layer 310 on the positive electrode sheet 11 and part of the diaphragm 20 corresponding to the avoidance groove 122 on the negative electrode sheet 12 can be accommodated inside the avoidance groove 122, which can effectively prevent the first insulating adhesive The layer 310 and the second insulating adhesive layer 320 increase the overall thickness of the cell after being stacked.

同时，贴附在极耳200上的第一绝缘胶层310可以防止极耳200在焊接区域111形成的毛刺和凹槽121边缘的毛刺刺穿隔膜20。贴附在负极片12上避让槽122上的第二绝缘胶层320可以防止避让槽122边缘形成的毛刺刺穿隔膜20。At the same time, the first insulating glue layer 310 attached to the tab 200 can prevent the burrs formed on the welding area 111 of the tab 200 and the burrs on the edge of the groove 121 from piercing the diaphragm 20 . The second insulating adhesive layer 320 attached to the escape groove 122 on the negative electrode sheet 12 can prevent the burr formed on the edge of the avoidance groove 122 from piercing the separator 20 .

需要说明的是，本申请仅以其中一种形式的正极片11和负极片12为例进行说明的。可以理解的是，如果有需要也可以在正极片11上与负极耳对应的位置处设置避让槽122，至于具体的设置方式和作用在上述内容中已经作了详细的介绍，在此不再一一赘述。It should be noted that this application only takes one form of the positive electrode sheet 11 and the negative electrode sheet 12 as an example for illustration. It can be understood that, if necessary, avoidance grooves 122 can also be provided on the positive electrode sheet 11 at the position corresponding to the negative electrode ear. As for the specific setting method and function, they have been introduced in detail in the above content, and will not be repeated here. A repeat.

为了更加清楚的对电芯结构进行解释说明，本申请提供了一种常规的型号为3862A0(成品电池的厚度为3.8mm，宽度6.2mm，长度10mm)的方形锂离子电池为例进行解释说明。In order to explain the cell structure more clearly, this application provides a conventional square lithium-ion battery of model 3862A0 (the thickness of the finished battery is 3.8mm, the width is 6.2mm, and the length is 10mm) as an example for explanation.

该方形锂离子电池包括正极片、负极片、隔膜和电解液。正极片包含正极集流体、正极活性物质层、正极耳和第一绝缘胶层；正极片上设置有凹槽(用于焊接正极耳)，正极耳焊接在凹槽内的正极集流体表面，正极耳与正极集流体通过激光焊接连接，由于在正极集流体上与正极耳相对的另外一侧的正极活性物质无影响，因此在另外一侧的正极活性物质层上无需粘贴绝缘胶层，只需在正极耳的表面覆盖有第一绝缘胶层即可。The prismatic lithium ion battery includes a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte. The positive electrode sheet includes a positive electrode current collector, a positive electrode active material layer, a positive electrode ear, and a first insulating adhesive layer; the positive electrode sheet is provided with a groove (for welding the positive electrode ear), and the positive electrode ear is welded on the surface of the positive electrode current collector in the groove, and the positive electrode ear It is connected with the positive electrode current collector by laser welding. Since the positive electrode active material on the other side of the positive electrode current collector opposite to the positive tab has no effect, there is no need to paste an insulating adhesive layer on the positive electrode active material layer on the other side. The surface of the positive tab is covered with the first insulating adhesive layer.

负极片包含负极集流体、负极活性物质层、凹槽(用于焊接负极耳)、避让槽(负极片上与正极耳相对应的位置处设置的凹槽)、第二绝缘胶层、第三绝缘胶层和负极耳。负极耳容置于凹槽内，第二绝缘胶层覆盖在凹槽上。避让槽槽表面覆盖有第三绝缘胶层，且避让槽用于容置第三绝缘胶层、隔膜和第一绝缘胶层的厚度。The negative electrode sheet includes a negative electrode current collector, a negative electrode active material layer, a groove (for welding the negative electrode ear), an avoidance groove (a groove provided on the negative electrode sheet corresponding to the position of the positive electrode ear), a second insulating adhesive layer, and a third insulating layer. Adhesive layer and negative tab. The negative electrode ear is placed in the groove, and the second insulating glue layer covers the groove. The surface of the escape groove is covered with a third insulating adhesive layer, and the escape groove is used to accommodate the thicknesses of the third insulating adhesive layer, the diaphragm and the first insulating adhesive layer.

其中，正极集流体厚度为0.01mm，负极集流体厚度为0.006mm。正极耳的材质为铝，厚度0.1mm，宽度6mm。正极耳与正极集流体重叠部分的长度为20mm。负极耳的材质镍，厚度0.1mm，宽度6mm。负极耳与负极集流体重叠部分的长度为20mm。Wherein, the thickness of the positive electrode current collector is 0.01 mm, and the thickness of the negative electrode current collector is 0.006 mm. The positive tab is made of aluminum, with a thickness of 0.1 mm and a width of 6 mm. The length of the overlapping portion of the positive electrode tab and the positive electrode current collector is 20 mm. The negative tab is made of nickel, with a thickness of 0.1mm and a width of 6mm. The length of the overlapping portion of the negative electrode tab and the negative electrode current collector is 20 mm.

正极耳通过激光焊与正极集流体焊接在一起，正极耳焊接区域111的宽度为4mm，长度为18mm。负极耳通过激光焊与负极集流体焊接在一起，负极耳焊接区域111的宽度为5mm，长度为15mm。正/负极耳背面的活性物质层直接与隔膜接触。The positive tab is welded to the positive current collector by laser welding, and the positive tab welding area 111 has a width of 4 mm and a length of 18 mm. The negative electrode tab is welded together with the negative electrode current collector by laser welding, and the width of the negative electrode tab welding area 111 is 5 mm, and the length is 15 mm. The active material layer on the back of the positive/negative tab is in direct contact with the separator.

另外，正极片上的凹槽通过激光清洗、发泡、机械等技术制作形成，凹槽的宽度为10mm、长度为25mm、深度为0.05mm。正极耳容置于凹槽中间，且凹槽距离正极片一端的距离为正极片总长的1/2。In addition, the groove on the positive electrode sheet is formed by laser cleaning, foaming, mechanical and other technologies. The width of the groove is 10mm, the length is 25mm, and the depth is 0.05mm. The positive electrode ear is placed in the middle of the groove, and the distance from the groove to one end of the positive electrode sheet is 1/2 of the total length of the positive electrode sheet.

负极片上的凹槽通过激光清洗、发泡、机械等技术制作形成，凹槽的宽度为10mm、长度为25mm、深度为0.05mm。负极耳容置于凹槽中间，且凹槽距负极片一端的距离为负极片总长的1/2。The groove on the negative plate is formed by laser cleaning, foaming, mechanical and other technologies. The width of the groove is 10mm, the length is 25mm, and the depth is 0.05mm. The negative electrode ear is placed in the middle of the groove, and the distance between the groove and one end of the negative electrode sheet is 1/2 of the total length of the negative electrode sheet.

负极片上的避让槽通过激光清洗、发泡、机械等技术制作形成，避让槽的宽度为10mm、长度为25mm、深度为0.04mm。避让槽距负极片一端的距离为负极片总长的1/4。The avoidance groove on the negative electrode sheet is formed by laser cleaning, foaming, mechanical and other technologies. The width of the avoidance groove is 10mm, the length is 25mm, and the depth is 0.04mm. The distance between the escape groove and one end of the negative electrode sheet is 1/4 of the total length of the negative electrode sheet.

需要说明的是，正极片上的凹槽带有缺口，缺口的形状为梯形，缺口沿正极片长度方向上的两个边长分别为8mm和10mm，缺口沿正极片宽度方向上的宽为2mm。而在负极片上的凹槽和避让槽上没有设置缺口。It should be noted that the groove on the positive electrode sheet has a notch, the shape of the notch is trapezoidal, the lengths of the two sides of the notch along the length direction of the positive electrode sheet are 8mm and 10mm, respectively, and the width of the notch along the width direction of the positive electrode sheet is 2mm. And there is no notch on the groove and avoidance groove on the negative electrode sheet.

第一绝缘胶层和第二绝缘胶层的尺寸大小一致，具体是：宽度为20mm，长度为30mm，厚度0.012mm。第三绝缘胶层的宽度为18mm，长度为28mm，厚度0.012mm。The first insulating adhesive layer and the second insulating adhesive layer have the same size, specifically: the width is 20 mm, the length is 30 mm, and the thickness is 0.012 mm. The width of the third insulating adhesive layer is 18mm, the length is 28mm, and the thickness is 0.012mm.

在将正极片和负极片与隔膜一起卷绕制成卷芯后，正极片的凹槽、负极片的凹槽以及避让槽槽相对的另一个侧面上的活性物质层不用覆盖绝缘胶层，可以直接与隔膜接触。在卷绕热压后，正极耳对应的第三绝缘胶层、隔膜以及第一绝缘胶层进入避让槽内，避免了电池厚度上升。After the positive electrode sheet and the negative electrode sheet are wound together with the diaphragm to form a winding core, the groove of the positive electrode sheet, the groove of the negative electrode sheet, and the active material layer on the opposite side of the escape groove do not need to cover the insulating adhesive layer. directly in contact with the diaphragm. After winding and hot pressing, the third insulating adhesive layer corresponding to the positive tab, the separator and the first insulating adhesive layer enter the avoidance groove, which prevents the thickness of the battery from increasing.

最后应说明的是：以上各实施例仅用以说明本申请的技术方案，而非对其限制；尽管参照前述各实施例对本申请进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分或者全部技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本申请各实施例技术方案的范围。Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present application. scope.

Claims

一种极片(10)，其特征在于，包括极片(10)本体和极耳(200)，所述极片(10)本体包括集流体(110)、第一活性物质层(120a)和第二活性物质层(120b)，所述第一活性物质层(120a)和所述第二活性物质层(120b)分别设置在所述集流体(110)的相对两个侧面；A pole piece (10), characterized in that it includes a pole piece (10) body and a pole lug (200), and the pole piece (10) body includes a current collector (110), a first active material layer (120a) and A second active material layer (120b), the first active material layer (120a) and the second active material layer (120b) are respectively arranged on two opposite sides of the current collector (110);

所述第一活性物质层(120a)上具有凹槽(121)，所述凹槽(121)的底壁为所述集流体(110)，所述极耳(200)设置在所述凹槽(121)内，且与所述集流体(110)焊接，以形成焊点组(112)；The first active material layer (120a) has a groove (121), the bottom wall of the groove (121) is the current collector (110), and the tab (200) is arranged in the groove (121), and welded with the current collector (110) to form a solder joint group (112);

所述焊点组(112)包括第一焊点(113)和第二焊点(114)，所述第一焊点(113)位于所述极耳(200)上，所述第二焊点(114)位于所述集流体(110)上，所述第一焊点(113)与所述第二焊点(114)连接。The welding point group (112) includes a first welding point (113) and a second welding point (114), the first welding point (113) is located on the tab (200), and the second welding point (114) is located on the current collector (110), and the first welding point (113) is connected to the second welding point (114).
根据权利要求1所述的极片(10)，所述集流体(110)背离所述凹槽(121)的表面设置有所述第二活性物质层(120b)，所述凹槽(121)在所述集流体(110)上的投影位于所述第二活性物质层(120b)在所述集流体(110)上的投影内。According to the pole piece (10) according to claim 1, the surface of the current collector (110) facing away from the groove (121) is provided with the second active material layer (120b), and the groove (121) The projection on the current collector (110) is located within the projection of the second active material layer (120b) on the current collector (110).
根据权利要求1所述的极片(10)，其特征在于，所述第二焊点(114)在所述集流体(110)背离所述极耳(200)的一侧形成凸起。The pole piece (10) according to Claim 1, characterized in that, the second welding spot (114) forms a protrusion on a side of the current collector (110) away from the pole lug (200).
根据权利要求3所述的极片(10)，其特征在于，所述第二活性物质层(120b)覆盖所述凸起。The pole piece (10) according to Claim 3, characterized in that, the second active material layer (120b) covers the protrusion.
根据权利要求1-4中任一项所述的极片(10)，其特征在于，所述第二焊点(114)的深度为所述集流体(110)厚度的50％～100％。The pole piece (10) according to any one of claims 1-4, characterized in that, the depth of the second welding spot (114) is 50%-100% of the thickness of the current collector (110).
根据权利要求1-5中任一项所述的极片(10)，其特征在于，所述凹槽(121)内具有焊接区域(111)，所述焊点组(112)位于所述焊接区域(111)内；The pole piece (10) according to any one of claims 1-5, characterized in that, there is a welding area (111) in the groove (121), and the welding point group (112) is located in the welding within the area (111);

所述焊接区域(111)的宽度D1为所述极耳(200)宽度D的50％～100％，和/或，所述焊接区域(111)的长度L1为所述极耳(200)与所述集流体(110)重叠部分长度L的50％～100％。The width D1 of the welding area (111) is 50%-100% of the width D of the tab (200), and/or, the length L1 of the welding area (111) is between the tab (200) and The overlapping portion length L of the current collector (110) is 50%-100%.
根据权利要求1-6中任一项所述的极片(10)，其特征在于，所述极耳(200)为正极耳(200)，所述正极耳(200)的厚度为所述集流体(110) 厚度的5倍～20倍；The pole piece (10) according to any one of claims 1-6, characterized in that, the pole tab (200) is a positive pole tab (200), and the thickness of the positive pole tab (200) is the set 5 to 20 times the thickness of the fluid (110);

和/或，所述极耳(200)为负极耳(200)，所述负极耳(200)的厚度为所述集流体(110)厚度的10倍～40倍。And/or, the tab (200) is a negative tab (200), and the thickness of the negative tab (200) is 10 to 40 times the thickness of the current collector (110).
根据权利要求1-6任一项所述的极片(10)，其特征在于，The pole piece (10) according to any one of claims 1-6, characterized in that,

所述极耳(200)的厚度为0.01mm～0.5mm，和/或，所述极耳(200)的宽度D为1mm～12mm，和/或，所述极耳(200)的长度为5mm～50mm；The thickness of the tab (200) is 0.01mm-0.5mm, and/or, the width D of the tab (200) is 1mm-12mm, and/or, the length of the tab (200) is 5mm ~50mm;

所述极耳(200)的厚度大于或等于所述凹槽(121)的深度。The thickness of the tab (200) is greater than or equal to the depth of the groove (121).
一种电池，其特征在于，包括权利要求1-8任一项所述的极片(10)。A battery, characterized by comprising the pole piece (10) according to any one of claims 1-8.
根据权利要求9所述的电池，其特征在于，所述极片(10)为两个，至少一个所述极片(10)上具有避让槽(122)，所述避让槽(122)与另一所述极片(10)上的所述凹槽(121)对应设置。The battery according to claim 9, characterized in that there are two pole pieces (10), at least one of the pole pieces (10) has an avoidance groove (122), and the avoidance groove (122) is connected with the other. The grooves (121) on a pole piece (10) are arranged correspondingly.