Plates and batteries

Abstract

The present application provides an electrode plate and a battery. The electrode plate according to the present application includes a first current collector and a first functional layer provided on at least one surface of the first current collector, and a plurality of first regions and a plurality of second regions are distributed at a distance on the surface of the first functional layer, and in the first regions, the content ratio of oxygen element to silicon element in the first functional layer is greater than 4:1. The electrode plate and battery according to the present application are used to at least solve the problem of initial efficiency of lithium batteries, and improve the battery capacity, thereby improving the battery energy density.

Description

[Technical field]

[0001] This application claims priority to the Chinese patent application filed on June 17, 2022 with the State Intellectual Property Office of the People's Republic of China, bearing application number 202210688699.X and entitled "Electrode Plate and Battery", and the Chinese patent application filed on June 17, 2022 with the State Intellectual Property Office of the People's Republic of China, bearing application number 202221520256.1 and entitled "Electrode Plate and Battery", the entire contents of which are incorporated herein by reference. This application relates to the technical field of lithium ion batteries, and in particular to plates and batteries. [Background technology]

[0002] Lithium-ion batteries have the advantages of high energy density, long service life, etc., and are therefore widely used in electric vehicles, power tools, and consumer electronics. In order to increase the energy density of lithium-ion batteries, research into the negative electrode plate of the battery has attracted the attention of related companies.

[0003] At present, commercialized lithium-ion battery negative plates mainly use graphite carbon-based negative electrode materials. Compared with graphite, silicon-containing negative electrode materials have significantly better energy density. However, during the actual charging and discharging process, on average, 4.4 lithium atoms are bonded to one silicon atom, and the lithium ions released from the positive electrode cannot return to the silicon negative electrode, resulting in a very low initial efficiency of 69%, a low utilization rate of lithium ions, and a low battery capacity.

[0004] Therefore, there is a need to solve the problem of low initial efficiency of lithium-ion batteries. Summary of the Invention [Problem to be solved by the invention]

[0005] The present application provides an electrode plate and a battery for solving at least the problem of low initial efficiency of lithium ion batteries. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the electrode plate of the present application includes a first current collector and a first functional layer provided on at least one surface of the first current collector, wherein a plurality of first regions and a plurality of second regions are distributed at a distance from each other on a surface of the first functional layer, and within the first regions, the content ratio of oxygen element to silicon element in the first functional layer is greater than 4:1.

[0007] In the electrode plate according to the present application, a plurality of the first regions and a plurality of the second regions are distributed at a distance from each other on the surface of the first functional layer, the first regions are used to replenish lithium material, and the content ratio of oxygen element to silicon element in the first functional layer in the first regions is greater than 4:1. This ensures that lithium silicate is easily generated and reduces the battery expansion rate during cycling. According to the present application, by early replenishing the lithium material in the electrode plate, the battery processed with the electrode plate according to the present application can fully utilize the replenished metallic lithium to form an SEI film during the initial charging and discharging process, suppressing the loss of the lithium source in the positive electrode, thereby improving the utilization rate of lithium ions and improving the initial cycle efficiency of the battery.

[0008] In one embodiment, the first region includes elements of carbon, oxygen, fluorine, phosphorus, and silicon.

[0009] In one embodiment, in the first region, the content ratio of elemental fluorine to elemental phosphorus in the first functional layer is greater than 7:1.

[0010] In one embodiment, the second region includes elements of carbon, oxygen, fluorine, phosphorus, and silicon.

[0011] In one embodiment, in the second region, the content ratio S1:S2 of oxygen element to silicon element in the first functional layer satisfies 2:1≦S1:S2≦4:1.

[0012] In one embodiment, in the second region, the content ratio S3:S4 of elemental fluorine and elemental phosphorus in the first functional layer satisfies 6:1≦S3:S4≦7:1.

[0013] In one embodiment, the content of elemental fluorine in the first functional layer located in the first region is greater than the content of elemental fluorine in the first functional layer located in the second region.

[0014] In one embodiment, the content of the phosphorus element in the first functional layer located in the first region is greater than the content of the phosphorus element in the first functional layer located in the first region.

[0015] In one embodiment, the content of oxygen elements in the first functional layer located in the first region is greater than the content of oxygen elements in the first functional layer located in the second region.

[0016] In one embodiment, the second region has a width of 0 μm to 4 mm and / or the first region has a width of 100 μm to 4 mm.

[0017] In one embodiment, the first functional layer comprises active material particles, The active material particles include at least one of a silicon material and a silicon oxide material, and a carbon material, and the mass of the silicon material and / or the silicon oxide material accounts for 7% to 50% of the total mass of the active material particles, or the active material particles include a carbon material and graphite; or The active material particles contain at least one of a silicon material and a silicon oxide material, and a carbon material, and the mass of the silicon material and / or the silicon oxide material accounts for 7% to 50% of the total mass of the active material particles.

[0018] In one embodiment, the extension direction of the first region forms a first included angle with the width direction of the first functional layer, and the first included angle is in the range of 0° to 45°; and / or The ratio of the total area of ​​the first regions to the total area of ​​the second regions is 0.7:1 to 3:1; and / or With respect to the surface of the first current collector, a portion of the first region farthest from the first current collector is higher than the second region, and a height difference between the portion of the first region farthest from the first current collector and the portion of the second region farthest from the first current collector is 0.1 μm to 8 μm.

[0019] In one embodiment, the electrode plate further includes a first tab and a first adhesive layer formed on a surface of the first functional layer, a first groove is provided in the first functional layer, at least a portion of the first tab is located in the first groove and covered by the first adhesive layer, and the first adhesive layer covers at least one of the first regions.

[0020] In one embodiment, the first groove has a first side, a second side and a third side, and a direction from the first side to the second side is parallel to a longitudinal direction of the first functional layer; The first adhesive layer has a portion located on the surface of the first functional layer on the first side of the first groove covering 0 to 8 of the first regions, and / or The first adhesive layer has a portion located on the surface of the first functional layer on the second side of the first groove covering 0 to 8 of the first regions, and / or The first adhesive layer has a portion located on the surface of the first functional layer on the third side of the first groove covering 0 to 40 of the first regions, and / or The first adhesive layer has a width of 1 mm to 5 mm in the longitudinal direction of the first functional layer at a portion located on the surface of the first functional layer on the first side of the first groove, and / or The first adhesive layer has a width of 1 mm to 5 mm in the longitudinal direction of the first functional layer at a portion located on the surface of the first functional layer on the second side of the first groove.

[0021] The battery according to the present application includes a sealed case and a cell located inside the sealed case, the cell including a first plate, which is the above-mentioned plate, and a second plate having an opposite polarity to the first plate.

[0022] In one embodiment, one end of the second plate is provided with a second adhesive layer in an area covered by the first plate, The number of the first regions in the first plate corresponding to the second adhesive layer is 0 to 20; and / or The second plate includes a second current collector and a second functional layer provided on a surface of the second current collector, and a second bare foil area where the second functional layer is not provided is present at one end of the second plate, and the second adhesive layer covers at least a portion of the second bare foil area and extends from the second bare foil area to the surface of the second functional layer; and / or The second adhesive layer has a width of 3 mm to 5 mm in the longitudinal direction of the second electrode plate.

[0023] In one embodiment, the first functional layer is provided with a first groove, and a third adhesive layer is provided on the surface of the second electrode plate at a position corresponding to the position of the first groove, and / or The second plate includes a second current collector and a second functional layer provided on a surface of the second current collector, the second functional layer having a second groove and a fourth adhesive layer covering the second groove, and a second tab provided on the second plate, at least a portion of the second tab being located within the second groove and covered by the fourth adhesive layer.

[0024] In one embodiment, the first groove has a first side, a second side and a third side, the third adhesive layer has a first projection on the first plate covering at least one of the first regions, and the first projection satisfies the following: a portion of the first projection located on the first side of the first groove covers 0 to 8 of the first regions; and / or The first projection has a portion located on the second side of the first groove covering 0 to 8 of the first regions, and / or The first projection has a portion located on the third side of the first groove covering 0 to 40 of the first regions, and / or The second groove has a fourth side, a fifth side, and a sixth side, the fourth adhesive layer has a projection on the first plate covering at least one of the first regions, and the fourth adhesive layer has a projection on the first plate of a portion located on the fourth side of the second groove covering 0 to 8 of the first regions, and / or The fourth adhesive layer covers 0 to 8 of the first regions of the first electrode plate in a portion located on a fifth side of the second groove, and / or The fourth adhesive layer covers a portion of the first region that is located on a sixth side of the second groove and has a projection of 0 to 40 on the first electrode plate. Effect of the Invention

[0025] According to the electrode plate and battery of the present application, the content ratio of fluorine and phosphorus in the first region is greater than 7:1, and the excess fluorine reacts with lithium ions to produce lithium fluoride, i.e., to produce a passivation layer. The SEI film rich in LiF inactive material improves the stability of the SEI film, thereby improving the cycle stability of silicon anode materials. During the formation process, the SEI film consumes lithium ions in the positive electrode part early, resulting in a low initial efficiency of the battery. However, the battery processed by forming the SEI film by fully utilizing the supplemented metallic lithium can effectively suppress the loss of lithium source in the positive plate, thereby improving the utilization rate of lithium ions and improving the initial cycle efficiency of the battery.

[0026] The electrode plate and battery according to the present application have a content ratio of fluorine and phosphorus elements greater than 7:1, which forms an SEI film rich in LiF inactive material, improves the stability of the SEI film, and thereby improves the cycle stability of the silicon negative electrode material.

[0027] According to the electrode plate and battery of the present application, a plurality of first regions are separated by second regions, that is, every two adjacent first regions are separated by a second region where lithium replenishment is not performed, and the lithium replenishment region does not cover the entire surface of the first functional layer. The second region allows the electrolyte to more easily infiltrate the electrode plate, and reduces side reactions between metallic lithium and the electrolyte, thereby improving the utilization rate of lithium metal, optimizing the performance of the electrode plate and the battery, significantly improving the capacity of the battery, and significantly improving the cycle performance of the battery. In addition, a first adhesive layer is provided on the surface of the first functional layer, and the first adhesive layer covers at least one first region. This prevents lithium deposition in the first region, and improves the performance of the electrode plate and the battery, such as safety.

[0028] According to the electrode plate and battery of the present application, the expansion of the battery can be effectively improved, and the number of charge / discharge cycles of the battery can be increased, which is advantageous for extending the service life of the battery. [Brief description of the drawings]

[0029] In order to more clearly describe the technical solutions in the embodiments of the present application or the prior art, the following briefly introduces the drawings that need to be used in the description of the embodiments or the prior art. Needless to say, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative labor. [Figure 1] FIG. 2 is a structural schematic diagram of an electrode plate according to an embodiment of the present application. [Diagram 2] FIG. 2 is an SEM image of a first region and a second region of a plate according to an embodiment of the present application. [Diagram 3] FIG. 4 is an SEM image of a second region of a plate according to an embodiment of the present application. [Figure 4] FIG. 2 is an area analysis EDS diagram of an SEM image of a first region of a plate according to an embodiment of the present application. [Diagram 5] FIG. 2 is a line analysis diagram of a first region and a second region of a plate according to an embodiment of the present application. [Figure 6]FIG. 6 is a distribution trend diagram of phosphorus element at the horizontal line AB position in FIG. 5 for the electrode plate according to the embodiment of the present application. [Figure 7] FIG. 6 is a distribution trend diagram of elemental fluorine at the position of the horizontal line AB in FIG. 5 for an electrode plate according to an embodiment of the present application. [Figure 8] FIG. 6 is a distribution trend diagram of oxygen element at the horizontal line AB position in FIG. 5 for the electrode plate according to the embodiment of the present application. [Figure 9] FIG. 2 is a comparison diagram of cycle performance curves between a battery according to an embodiment of the present application and a conventional battery. [Figure 10] FIG. 2 is a comparison diagram of expansion curves of cycle performance between a battery according to an embodiment of the present application and a conventional battery. [Figure 11] 2 is a structural schematic diagram of a cross section perpendicular to the thickness direction of a negative electrode current collector of a first electrode plate according to an embodiment of the present application. FIG. [Figure 12] 2 is a structural schematic diagram of a cross section perpendicular to the thickness direction of a negative electrode current collector of a first electrode plate according to an embodiment of the present application. FIG. [Figure 13] 2 is a schematic diagram of a cross-sectional structure perpendicular to the thickness direction of a negative electrode current collector of a second electrode plate according to an embodiment of the present application. FIG. [Figure 14] FIG. 2 is a surface morphology diagram of a first electrode plate according to an embodiment of the present application measured by a 3D microscope. [Figure 15] FIG. 2 is a schematic diagram of the arrangement structure of lithium ribbons in the manufacturing process of a first electrode plate according to an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application are described below in a clear and complete manner in conjunction with the drawings in the present application. Needless to say, the described embodiments are only some of the embodiments in the present application, and not all of the embodiments. Based on the embodiments in the present application, all other embodiments that a person skilled in the art can obtain without creative labor fall within the scope of protection of the present application.

[0031] Although the plate processed with silicon oxide anode material has an ideal specific capacity, the lithium ions released from the cathode are absorbed in the silicon oxide anode material and react preferentially with silicon oxide to generate inactive substances such as lithium silicate and lithium silicon alloy, and the silicon particles burst, which causes the solid electrolyte interface (SEI) film to grow, burst and repair repeatedly, accumulating in large quantities during the growth process, consuming the lithium source, causing capacity fading, low initial efficiency and poor cycle performance.

[0032] In view of the above background, the electrode plate and battery according to the present application have a plurality of first regions 30 and a plurality of second regions 40 distributed at a distance from each other on the surface of the first functional layer 20, and the content ratio of oxygen element to silicon element in the first functional layer 20 within the first region 30 is greater than 4:1. This ensures that lithium silicate is easily generated and reduces the battery expansion rate during cycling. During the formation process, the SEI film consumes lithium ions in the positive electrode portion early, resulting in a low initial efficiency of the battery. However, by forming an SEI film with replenished metallic lithium and suppressing the loss of lithium ions in the positive electrode, the utilization rate of lithium ions is improved, thereby achieving the effect of improving the initial efficiency of the battery.

[0033] The electrode plate and the battery according to the present application will be described below with reference to the drawings.

[0034] As shown in FIG. 1, the electrode plate of the present application includes a first current collector 10 and a first functional layer 20 provided on at least one surface of the first current collector 10, and a plurality of first regions 30 and a plurality of second regions 40 are distributed at a distance on the surface of the first functional layer 20, and within the first region 30, the content ratio of oxygen element to silicon element in the first functional layer 20 is greater than 4:1, and the first region 30 contains lithium element.

[0035] In the electrode plate of the present application, the first functional layer 20 is an active material layer, a plurality of first regions 30 and a plurality of second regions 40 are distributed at a distance on the surface of the first functional layer 20, the first regions 30 are used for replenishing lithium material, and the content ratio of oxygen element to silicon element in the first functional layer 20 in the first regions 30 is greater than 4:1, which can ensure that lithium silicate can be easily generated and reduce the battery expansion rate during cycling.

[0036] The infiltration of the electrolyte is generally achieved by capillary action. The electrode plate according to the present application utilizes a structure in which the second region 40 and the first region 30 are distributed at a distance from each other, and the electrolyte can infiltrate into the electrode plate by penetrating through the second region 40, which suppresses the impediment to infiltration of the electrode plate and is favorable for uniform infiltration of the electrode plate, thereby improving the infiltration effect of the battery and thereby improving the cycle life of the battery.

[0037] The first region 30 contains carbon, oxygen, fluorine, phosphorus, and silicon elements. The second region 40 contains carbon, oxygen, fluorine, phosphorus, and silicon elements.

[0038] In the first region 30, the content ratio of fluorine and phosphorus in the first functional layer 20 is greater than 7:1. This forms an SEI film rich in LiF inactive material, improves the stability of the SEI film, and improves the charge-discharge cycle stability of the battery. According to the present application, by supplementing the lithium material to the plate early, the battery processed with the plate according to the present application fully utilizes the supplemented metallic lithium to form an SEI film during the initial charge-discharge process, suppresses the loss of lithium source in the positive electrode, improves the utilization rate of lithium ions, and achieves the effect of improving the initial cycle efficiency of the battery.

[0039] In one embodiment, the content ratio of oxygen element to silicon element in the first region 30 may be 4:1, 5:1, 6:1, or 7:1.

[0040] In addition, in the first region 30, when the content ratio of oxygen element to silicon element is greater than 4:1, such as when the content ratio of oxygen element to silicon element is 5:1, the excess oxygen element and the supplemented lithium ions chemically react to produce lithium oxide or lithium carbonate, resulting in a decrease in the utilization rate of the lithium ions.

[0041] In one embodiment, the first region 30 is formed by providing a lithium material layer on the surface of the first functional layer 20, and the surface density of lithium contained in the lithium material layer is 0.09 mg / cm 2 ~0.5mg / cm 2 The lithium material layer may be provided on the surface of the first functional layer 20 by rolling to form the first region 30. The lithium material layer may be a lithium foil having an areal density of metallic lithium of 0.09 mg / cm. 2 ~0.5mg / cm 2 The first functional layer 20 includes graphite and a silicon material, and the mass of the silicon material occupies 7% to 50% of the total mass of the active material particles. This ensures that the amount of metallic lithium matches the amount of the silicon material. The lithium material layer may be a plurality of lithium ribbons.

[0042] The first functional layer 20 contains active material particles.

[0043] In one embodiment, the active material particles contain at least one of a silicon material and a silicon oxide material, and a carbon material, and the mass of the silicon material and / or the silicon oxide material accounts for 7% to 50% of the total mass of the active material particles, and accordingly, the surface density of metallic lithium contained in the first region 30 is 0.09 mg / cm. 2 ~0.5mg / cm 2 This ensures that the amount of metallic lithium is matched to the amount of silicon material and / or silicon oxide material.

[0044] In one embodiment, the active material particles include a carbon material and graphite.

[0045] In one embodiment, the areal density of metallic lithium is 0.09 mg / cm 2~0.5mg / cm 2 The active material particles contain at least one of a silicon material and a silicon oxide material, and a carbon material, and the mass of the silicon material and / or the silicon oxide material accounts for 7% to 50% of the total mass of the active material particles.

[0046] In one embodiment, as shown in FIG. 1, the electrode plate according to the present application is a negative electrode plate, and the first current collector 10 can be copper foil, titanium foil, nickel mesh, stainless steel foil, lithium copper alloy film or carbon cloth.

[0047] In one embodiment, the first functional layer 20 is provided on both sides of the first current collector 10 .

[0048] In the first region 30, the content ratio of fluorine and phosphorus in the first functional layer 20 is greater than 7:1. In the process of processing the electrode plate, the first functional layer 20 in the first region 30 is contacted with lithium ions early to generate a passivation reaction, forming an SEI film, which is a passivation layer rich in LiF inactive material. The battery processed in this manner forms an SEI film rich in LiF inactive material during formation, improving the stability of the SEI film and thereby improving the stability of the battery cycle. According to the present application, by early replenishing the electrode plate with lithium material, the battery processed with the electrode plate according to the present application fully utilizes the replenishing metallic lithium to form an SEI film during the initial charge and discharge process, suppressing the loss of the lithium source of the positive electrode, improving the utilization rate of lithium ions, and achieving the effect of improving the initial cycle efficiency of the battery.

[0049] Considering that the electrolyte is lithium hexafluorophosphate, the content ratio of fluorine and phosphorus in the first region 30 is greater than 7:1, and the excess fluorine reacts with lithium ions to form an SEI film rich in LiF inactive materials, thereby improving the stability of the SEI film and improving the stability of the battery cycle. During the formation of the SEI film, the lithium replenished early is consumed to form the SEI film, and the consumption of the positive electrode lithium is suppressed, thereby improving the charge and discharge efficiency.

[0050] The following description will be made with reference to Fig. 2. Fig. 2 is a diagram obtained by photographing the first region 30 and the second region 40 with a scanning electron microscope (abbreviated as SEM) at a magnification of 50x to 5.0kx, and shows the first region 30 and the second region 40. The second region 40 is used to provide a region between the adjacent first regions 30 that separates them, and the second region 40 is a path for infiltrating into the electrode plate, which is advantageous for improving the infiltration effect of the electrode plate.

[0051] An ultra-thin metallic lithium ribbon is manufactured using asynchronous rolling technology, and a region containing metallic lithium corresponding to the first region 30 and a region not containing metallic lithium corresponding to the second region 40 are formed on the surface of the ultra-thin metallic lithium ribbon. The first region 30 is formed on the surface of the first functional layer 20 by transferring lithium ions in the metallic lithium ribbon to the first region 30. The region not containing metallic lithium corresponds to the second region 40.

[0052] In one embodiment, as shown in FIG. 2, in order to meet the requirements of lithium replenishment areal density and infiltration uniformity, the width of the first region 30 is 100 μm to 4 mm, that is, the distance between two adjacent second regions 40 is 100 μm to 4 mm.

[0053] In one embodiment, the distance between two adjacent second regions 40 may be 100 μm, 1 mm, 2 mm, 3 mm, or 4 mm.

[0054] In one embodiment, in order to meet the requirements of lithium replenishment areal density and infiltration uniformity, the width of the second region 40 is 0 μm to 4 mm, that is, the distance between two adjacent first regions 30 is 0 μm to 4 mm.

[0055] According to the electrode plate of the present application, the second region 40 and the first region 30 are distributed at a distance from each other and the width of the second region 40 and the width of the first region 30 are limited, which is advantageous in achieving the required lithium replenishment surface density and improving the uniformity of the electrolyte infiltrating the electrode plate.

[0056] In one embodiment, the distance between two adjacent first regions 30 may be 10 μm, 1 mm, 2 mm, 3 mm, or 4 mm.

[0057] After the lithium ions are locally absorbed in the silicon particles located in the first region 30, they migrate to the region where no lithium ions are absorbed due to the concentration difference and potential difference, forming a transition region 60 between the first region 30 and the second region 40, and distributing the lithium ions uniformly within the first region 30. This achieves the effect of making the lithium absorption state consistent, avoiding lithium precipitation and purple spots caused by local excess of lithium ions, and improving the uniformity of the overall lithium absorption.

[0058] In order to reduce the expansion rate of the battery during cycling, the plate is subjected to a lithium replenishment process. As a result, in the first region 30, metallic lithium and silicon react to generate lithium silicate as a buffer layer, which reduces the expansion of the battery during cycling. In the first region 30, the content ratio of oxygen element to silicon element in the first functional layer 20 is greater than 4:1. In the second region 40, the content ratio S1:S2 of oxygen element to silicon element in the first functional layer 20 satisfies 2:1≦S1:S2≦4:1. In addition, the content of oxygen element in the first functional layer 20 located in the first region 30 is greater than the content of oxygen element in the first functional layer 20 located in the second region 40.

[0059] In order to prevent the silicon particles from bursting during the lithium absorption process, and the SEI film from growing-bursting-repairing repeatedly, accumulating in large quantities during the growth process, and consuming lithium ions, resulting in attenuation of battery capacity, low initial efficiency, and poor cycle performance, an SEI film rich in LiF inactive substances is manufactured, and the stability of the SEI film is improved, thereby improving the cycle stability of the silicon negative electrode material. The content ratio of the fluorine element to the phosphorus element in the first functional layer 20 in the first region 30 is greater than 7:1. The content ratio S3:S4 of the fluorine element to the phosphorus element in the first functional layer 20 in the second region 40 satisfies 6:1≦S3:S4≦7:1. In addition, the content of the fluorine element in the first functional layer 20 located in the first region 30 is greater than the content of the fluorine element in the first functional layer 20 located in the second region 40. The content of the phosphorus element in the first functional layer 20 located in the first region 30 is greater than the content of the phosphorus element in the first functional layer 20 located in the first region 30.

[0060] The battery according to the present application includes a sealed case and a cell located inside the sealed case, and the cell includes a first plate that is the above-mentioned electrode plate, and a second plate.

[0061] [Example 1] In this embodiment, the active material particles of the first functional layer 20 include graphite and a silicon oxide material, and the mass ratio of the silicon oxide material may be 7% of the total mass of the active material particles, and accordingly, the surface density of metallic lithium contained in the first region 30 may be 0.12. In the first region 30, the content ratio S1:S2 of oxygen element to silicon element is 5:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 7:1 in the first region 30. In the second region 40, the content ratio S1:S2 of oxygen element to silicon element is 4:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 6:1 in the second region 40.

[0062] [Example 2] In this embodiment, the active material particles of the first functional layer 20 include graphite and a silicon oxide material, and the mass ratio of the silicon oxide material may be 20% of the total mass of the active material particles, and accordingly, the surface density of metallic lithium contained in the first region 30 may be 0.22. In the first region 30, the content ratio S1:S2 of oxygen element to silicon element is 6:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 7.5:1 in the first region 30. In the second region 40, the content ratio S1:S2 of oxygen element to silicon element is 4:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 6:1 in the second region 40.

[0063] [Example 3] In this embodiment, the active material particles of the first functional layer 20 include graphite and a silicon oxide material, and the mass ratio of the silicon oxide material may be 30% of the total mass of the active material particles, and accordingly, the surface density of metallic lithium contained in the first region 30 may be 0.32. In the first region 30, the content ratio S1:S2 of oxygen element to silicon element is 7:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 8:1 in the first region 30. In the second region 40, the content ratio S1:S2 of oxygen element to silicon element is 4:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 6:1 in the second region 40.

[0064] [Example 4] In this embodiment, the active material particles of the first functional layer 20 include graphite and a silicon oxide material, and the mass ratio of the silicon oxide material may be 40% of the total mass of the active material particles, and accordingly, the surface density of metallic lithium contained in the first region 30 may be 0.42. In the first region 30, the content ratio S1:S2 of oxygen element to silicon element is 8:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 8.5:1 in the first region 30. In the second region 40, the content ratio S1:S2 of oxygen element to silicon element is 4:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 6:1 in the second region 40.

[0065] [Example 5] In this embodiment, the active material particles of the first functional layer 20 include graphite and a silicon oxide material, and the mass ratio of the silicon oxide material may be 50% of the total mass of the active material particles, and accordingly, the surface density of metallic lithium contained in the first region 30 may be 0.5. In the first region 30, the content ratio S1:S2 of oxygen element to silicon element is 9:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 9:1 in the first region 30. In the second region 40, the content ratio S1:S2 of oxygen element to silicon element is 4:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 6:1 in the second region 40.

[0066] In the above-mentioned Examples 1 to 5, the active material particles of the first functional layer 20 contain graphite and a silicon oxide material, the mass ratio of the silicon oxide material may be 7% to 50% of the total mass of the active material particles, the graphite may be artificial graphite, natural graphite, or modified graphite, and the surface density of metallic lithium contained in the first region 30 may be 0.09 mg / cm. 2 ~0.5mg / cm 2 This ensures that the amount of metallic lithium is in accordance with the amount of silicon particles. If the amount of metallic lithium is too large, the lithium ions react with the electrolyte and precipitate, lowering the utilization rate of the lithium ions. If the amount of metallic lithium is too small, the effect of lithium replenishment is not significant, and the initial efficiency is not significantly improved.

[0067] [Example 6] In this embodiment, the active material particles of the first functional layer 20 include graphite and a silicon oxide material, and the mass ratio of the silicon oxide material may be 7% of the total mass of the active material particles, and accordingly, the surface density of metallic lithium contained in the first region 30 may be 0.18. In the first region 30, the content ratio S1:S2 of oxygen element to silicon element is 6:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 7:1 in the first region 30. In the second region 40, the content ratio S1:S2 of oxygen element to silicon element is 4:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 6:1 in the second region 40.

[0068] [Example 7] In this embodiment, the active material particles of the first functional layer 20 include graphite and a silicon oxide material, and the mass ratio of the silicon oxide material may be 30% of the total mass of the active material particles, and accordingly, the surface density of metallic lithium contained in the first region 30 may be 0.28. In the first region 30, the content ratio S1:S2 of oxygen element to silicon element is 7.5:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 8:1 in the first region 30. In the second region 40, the content ratio S1:S2 of oxygen element to silicon element is 4:1, and the content ratio S3:S4 of fluorine element to phosphorus element is 6:1 in the second region 40.

[0069] [Example 8] In this embodiment, the active material particles of the first functional layer 20 include graphite and a silicon oxide material, and the mass ratio of the silicon oxide material may be 50% of the total mass of the active material particles, and accordingly, the surface density of metallic lithium contained in the first region 30 may be 0.34. In the first region 30, the content ratio S1:S2 of oxygen element to silicon element is 8:1, and the content ratio S3:S4 of fluorine element to phosphorus element in the first region 30 is 8.5:1. In the second region 40, the content ratio S1:S2 of oxygen element to silicon element is 4:1, and the content ratio S3:S4 of fluorine element to phosphorus element in the second region 40 is 6:1.

[0070] In the above-described Examples 6 to 8, the active material particles of the first functional layer 20 contain graphite and a silicon oxide material, and the mass ratio of the silicon oxide material may be 7% to 50% of the total mass of the active material particles, and accordingly, the surface density of metallic lithium contained in the first region 30 is 0.09 mg / cm. 2 ~0.5mg / cm 2 This allows the amount of metallic lithium to match the amount of silicon particles, and prevents the lithium ion utilization rate from decreasing due to the reaction of the lithium with the electrolyte and precipitation caused by the metallic lithium being too much, and prevents the effect of lithium supplementation from being not significant and the initial efficiency from not being significantly improved due to the metallic lithium being too small.

[0071] During processing, the first functional layer 20 is applied to the surface of the first current collector 10, and then baked in a dry environment at a temperature of 90° C. for 24 hours to control the moisture content to 300 ppm or less to obtain a semi-finished electrode plate. Then, an ultra-thin metallic lithium ribbon is manufactured by asynchronous rolling technology, and the semi-finished electrode plate is coated with the ultra-thin metallic lithium ribbon to manufacture the electrode plate.

[0072] The battery according to the present application includes a sealed case and a cell located inside the sealed case, and the cell includes a first plate and a second plate, which are the above-mentioned plates.

[0073] In one embodiment, the second plate is a positive plate and the first plate is a negative plate.

[0074] During processing, the first electrode plate, the second electrode plate, and the separator are stacked in order, with the separator positioned between the first electrode plate and the second electrode plate to separate them. After that, the cells are wound to obtain a cell, which is then placed in a sealed case, and electrolyte is injected into the sealed case, vacuum sealed, left to stand, and chemically formed. The cells are charged at a constant current of 0.1C to a 4% state of charge (abbreviated as SOC), and then charged at a constant current of 0.2C to a 10% SOC, and then shaped and tested for capacity to obtain a pouch-type lithium-ion battery.

[0075] In one embodiment, the sealed case may be an aluminum plastic film, and the electrolyte may be lithium hexafluorophosphate.

[0076] In one embodiment, the first region 30 is a lithium-replenished region and the second region 40 is a non-lithium-replenished region. The first region 30 is bright and the second region 40 is dark as measured by 3D microscopy (as shown in FIG. 14).

[0077] In one embodiment, lithium can be replenished according to the following process. As shown in FIG. 15, a plurality of lithium ribbons 80 are distributed at intervals on the surface of the first functional layer 20, and gaps C that expose the surface of the first functional layer 20 are present between the plurality of lithium ribbons 80. After a reaction such as chemical conversion is performed during the manufacturing process of the battery, a first region 30 that is a lithium replenished region is formed in the region where the lithium ribbons 80 are provided, and a second region 40 that is a lithium unreplenished region is formed in the gaps C that exist between the plurality of lithium ribbons 80. As shown in FIG. 14, the first region 30 is discontinuous, and the second region 40 is favorable for the infiltration of the electrolyte into the electrode plate, which can improve the utilization rate of the lithium ribbons and optimize the electrode plate and battery performance.

[0078] In the lithium replenishment process, the semi-finished electrode plate on which the first functional layer 20 is formed is baked in a dry environment at about 90°C for about 24 hours to control the moisture content to 300 ppm or less, and then the lithium ribbon 80 is placed on the surface of the baked electrode plate and processed such as crimping, after which the lithium ribbon 80 is coated on the first functional layer 20 to replenish lithium.

[0079] The above-mentioned electrode plate can be manufactured by a coating method, and the manufacturing process generally includes steps such as material preparation (slurry preparation), coating (applying the slurry to the surface of the current collector substrate to form the first functional layer 20), roll pressing, slitting (slitting based on parameters such as the predetermined size and shape of the electrode plate), and baking, and then further performing subsequent processes such as lithium replenishment.

[0080] In one embodiment, the lithium ribbon 80 used may include a short lithium ribbon whose length is smaller than the width of the first functional layer 20 (the distribution mode of the short lithium ribbon is shown in FIG. 15, and the surface form of the electrode plate formed thereby is shown in FIG. 14). A plurality of short lithium ribbons may be sequentially placed along the width direction (direction indicated by arrow B) of the first functional layer 20 to form a row, and then, the same process may be repeated to form another row adjacent to the previous row in the longitudinal direction (direction indicated by arrow A) of the first functional layer 20, and the length of each row may be equal to or less than the width of the electrode plate, but is not limited thereto. A plurality of short lithium ribbons may be irregularly distributed on the surface of the first functional layer 20, or long lithium ribbons whose length is approximately the same as the width of the first functional layer 20 may be distributed at intervals on the surface of the first functional layer 20 (for example, a gap exists between any two adjacent long lithium ribbons, and the gap forms the second region 40 after chemical formation).

[0081] In one embodiment, the amount of lithium ribbon 80 used is such that the ratio of the total mass of the lithium ribbon 80 provided on the surface of the first functional layer 20 to the area of ​​the surface of the first functional layer 20 (the surface facing the first current collector 10) is 0.09 to 0.5 mg:1 m 2 can be satisfied.

[0082] In one embodiment, the thickness of the lithium ribbon 80 may be 1.9 μm to 9 μm. Since the theoretical specific capacity of pure metallic lithium is very high, when lithium is replenished to the entire surface of the electrode plate, the thickness of the metallic lithium is usually required to be about 1 μm, which is very difficult to manufacture and has poor consistency. On the other hand, in the present application, lithium is replenished so as to cover a part of the surface with an ultra-thin metallic lithium ribbon, and the ultra-thin metallic lithium ribbon forms a discontinuous covering state such as stripes / ripples on the surface of the first functional layer 20, which effectively replenishes lithium and improves the utilization rate of lithium metal, while having advantages such as easy manufacture and good consistency.

[0083] In one embodiment, lithium is typically replenished by pressing a lithium ingot to a micrometer-level thickness and then placing the resulting micrometer-level lithium ribbon on the surface of the first functional layer 20. For example, in some embodiments, a lithium ingot having a thickness of 200 μm to 2 mm is rolled into a lithium ribbon 80 having a thickness of 1.9 μm to 9 μm, which is then placed on the surface of the first functional layer 20 to replenish the lithium.

[0084] In one embodiment, the lithium source supplemented with lithium may be absorbed into the active material particles in the first region 30 to form an inorganic salt layer. That is, the material constituting the inorganic salt layer is an inorganic salt, and the inorganic salt layer is formed by the lithium element supplemented to the first region 30 being absorbed into the active material particles of the first region 30, and the inorganic salt layer contains at least one of lithium fluoride, lithium carbonate, lithium silicate, and the like.

[0085] In one embodiment, the first regions 30 and the second regions 40 are alternately arranged / distributed at a distance from each other, i.e., a plurality of first regions 30 and a plurality of second regions 40 are distributed on the surface of the first functional layer 20, and the plurality of second regions 40 form a plurality of first regions 30 at a distance from each other on the surface of the first functional layer 20.

[0086] Here, the multiple first regions 30 may be distributed along the longitudinal direction of the first functional layer 20 / electrode plate (the direction indicated by arrow A), i.e., the multiple first regions 30 and the multiple second regions 40 may be distributed alternately along the longitudinal direction of the first functional layer 20 / electrode plate.

[0087] In one embodiment, as shown in Figures 11, 12 and 14, the extension direction / longitudinal direction of the first region 30 may form a first included angle with the width direction of the first functional layer 20, and the first included angle may be 0° to 60°. In one embodiment, the first included angle may be 0° to 45°, for example, 0° (i.e., the longitudinal direction of the first region 30 is parallel to the width direction of the first functional layer 20), 10°, 20°, 30°, 40° or 45°. This is advantageous for the lithium replenishment and electrolyte infiltration effect of the electrode plate, and does not affect the winding along the longitudinal direction of the electrode plate, which is advantageous for the manufacture and performance of the battery.

[0088] Here, the extending directions of the multiple first regions 30 may be the same or different, that is, the first included angles formed with the width direction of the first functional layer 20 may be the same or different.

[0089] In addition, in the width direction of the first functional layer 20 / electrode plate, the distance between the first region 30 closest to the outer edge / edge of the first functional layer 20 and the outer edge of the first functional layer 20 is A, and A may be 0 to 2 mm, for example, 0 (i.e., the outer edges of the first region 30 and the first functional layer 20 are flush), 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc. The ratio of A to the width of the first functional layer 20 may be 0 to 0.03, for example, 0, 0.01, 0.02, 0.03, etc.

[0090] In one embodiment, at least one first region 30 forms a row in the width direction of the first functional layer 20. The row may be continuous (not separated by a second region 40) formed by one first region 30, or may be discontinuous (formed by sequentially arranging a plurality of first regions 30 along the width direction of the first functional layer 20, with adjacent first regions 30 separated by a second region 40 present between them).

[0091] Moreover, the first region 30 extends along the width direction of the first functional layer 20. The first region 30 may have a substantially flat structure in the width direction of the first functional layer 20, or may have a curved or bent structure.

[0092] Also, in the longitudinal direction of the first functional layer 20 / electrode plate, the distance between the first region 30 closest to the outer edge of the first functional layer 20 and the outer edge of the first functional layer 20 (i.e., the width in the longitudinal direction of the first functional layer 20 of the second region 22 closest to the outer edge of the first functional layer 20) may be 0 to 4 mm, for example, 100 μm to 4 mm.

[0093] In one embodiment, the first functional layer 20 has a first end and a second end facing each other, and the direction from the first end to the second end is parallel to the longitudinal direction of the first functional layer 20. The distance w1 between the first region 30 closest to the first end and the edge of the first end of the first functional layer 20 (the edge of the first functional layer 20) is 100 μm to 4 mm, for example, 100 μm, 300 μm, 500 μm, 700 μm, 1 mm, 2 mm, 3 mm, 4 mm, etc. That is, in the longitudinal direction of the first functional layer 20, the width of the second region 40 existing between the first region 30 closest to the first end and the edge of the first end is w1, and the distance w2 between the first region 30 closest to the second end (the edge of the first functional layer 20) and the edge of the second end of the first functional layer 20 is 0 μm to 4 mm, for example, 0, 100 μm, 300 μm, 500 μm, 700 μm, 1 mm, 2 mm, 3 mm, 4 mm, etc.

[0094] When w2 = 0, there is no second region between the first region 30 closest to the second end of the first functional layer 20 and the edge of the second end of the first functional layer 20 (i.e., the width w2 of the second region 40 between the first region 30 closest to the second end and the edge of the second end is 0). When w2 is not 0 (i.e., 0 < w2 ≤ 4 mm), along the longitudinal direction of the first functional layer 20, a second region 40 exists between the first region 30 closest to the second end of the first functional layer 20 and the edge of the second end, and the width of the second region 40 is w2.

[0095] In one embodiment, w1 and w2 may be the same or different.

[0096] In order to further achieve both the lithium replenishment effect and improved electrolyte permeability, in some preferred embodiments, the ratio of the total area of ​​the multiple first regions 30 (i.e., the sum of the areas of the multiple first regions 30) to the total area of ​​the multiple second regions 40 (i.e., the sum of the areas of the multiple second regions 40) is 0.7:1 to 3:1, for example 0.7:1, 1:1, 1.5:1, 2:1, 2.5:1, or 3:1.

[0097] Here, the outlines of the first regions 30 and the second regions 40 can be captured with a microscope, and the ratio of the total area of ​​the plurality of first regions 30 to the total area of ​​the plurality of second regions 40 can be measured.

[0098] Generally, there is a boundary between the first region 30 and the second region 40, and the first region 30 is higher than the second region 40 with respect to the surface of the first current collector 10 as the reference; i.e., in the thickness direction of the first functional layer 20, the distance a between the part of the first region 30 farthest from the first current collector 10 and the first current collector 10 is greater than the distance b between the part of the second region 40 farthest from the first current collector 10 and the first current collector 10 (a>b).

[0099] In some embodiments, the difference in altitude between the portion of the first region 30 farthest from the first current collector 10 and the portion of the second region 40 farthest from the first current collector 10 is 0.1 μm to 8 μm (i.e., ab=0.1 to 8 μm), such as 0.1 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, or 8 μm.

[0100] In one embodiment, the method of measuring the height difference between the first region 30 and the second region 40 may include, but is not limited to, (1) a method of sputtering a lithium-refilled electrode plate using an ion milling (CP) device to obtain a cross section, and then taking an image at a desired magnification using a scanning electron microscope (SEM) to obtain the height difference, and (2) a method of taking an image at a desired magnification using a 3D microscope, and then measuring the height difference using a profiler.

[0101] In some embodiments, the first functional layer 20 is provided with a first groove 21 covered by a first adhesive layer 81. Here, the first groove 21 may be a tab groove for providing a tab. In some embodiments, the electrode plate further includes a first tab 91 and a first adhesive layer 81 formed on the surface of the first functional layer 20, and at least a part of the first tab 91 is located in the first groove 21 and covered by the first adhesive layer 81 (i.e., the part of the first tab 91 located in the first groove 21 is covered by the first adhesive layer 81). This can protect the tab area and improve the safety of the electrode plate and the battery, for example, it can prevent lithium in the lithium supplement area around the first tab from migrating to the positive electrode tab area (the tab groove in which the corresponding positive electrode tab is located) during charging and discharging, and the resulting problem of lithium precipitation in the negative electrode tab area can be avoided.

[0102] In one embodiment, the first adhesive layer 81 is provided on a partial area of ​​the surface of the first functional layer 20, i.e., partially covers the first functional layer 20. The first adhesive layer 81 covers at least one first region 30.

[0103] In one embodiment, at least a portion of the bottom surface of the first groove 21 is the surface of the first current collector 10, i.e., a portion of the bottom surface of the first groove 21 exposes the first current collector 10. The first tab 91 may be connected to the first current collector 10 exposed at the bottom surface of the first groove 21, and more specifically, may be welded to the first current collector 10 exposed at the bottom surface of the first groove 21.

[0104] Here, the plate may be a center-placed tab (CPT) plate in which the tab is provided in the middle rather than at the end.

[0105] In one embodiment, the first groove 21 is at least flanked on both sides by the first functional layer 20. In some embodiments, in a plane perpendicular to the thickness direction of the first current collector 10, the first groove 21 has one side flush with one long side of the first current collector 10 and the remaining side surrounded by the first functional layer 20, i.e., the first groove 21 has an opening toward one long side of the first current collector 10. After the first tab 91 is provided, one end of the first tab 91 may extend from the outer edge of the first current collector 10 through the opening. Specifically, the first tab 91 extends from the outer edge of the first current collector 10 through the opening along the longitudinal direction. A portion of the first tab 91 located within the first groove 21 (i.e., a portion not extending from the outer edge of the first current collector 10) is covered by the first adhesive layer 81 (as shown in FIG. 12 ).

[0106] Here, the longitudinal direction of the first tab 91 is parallel to the longitudinal direction of the first region 30 / second region 40 (that is, the extension direction of the first tab 200 coincides with that of the first region 30 / second region 40).

[0107] As shown in FIG. 11, the first groove 21 has a rectangular shape when projected onto the first current collector 10, one of its short sides is flush with one of the long sides of the first current collector 10, and the remaining three sides are surrounded by the first functional layer 20.

[0108] In one embodiment, the first groove 21 has opposing first and second sides and opposing third and fourth sides, with the third / fourth sides located between the first and second sides (the third / fourth sides connect the first and second sides), and the direction from the first side to the second side is parallel to the direction from the first region to the second region.

[0109] 11 and 12, the first side is the left side, the second side is the right side, the third side is the bottom side, and the fourth side is the top side, and the left side, right side, and bottom side of the first groove 21 are all surrounded by the first functional layer 20, and there is no first functional layer 20 on the top side (i.e., the top side of the first groove 21 is flush with the edge of the first functional layer 20). The direction from the first side to the second side is parallel to the longitudinal direction of the first functional layer 20, and the direction from the third side to the fourth side is parallel to the width direction of the first functional layer 20.

[0110] Here, the first adhesive layer 81 extends to the surface of the first functional layer 20 around the first groove 21. The portion of the first adhesive layer 81 located on the surface of the first functional layer 20 on the first side of the first groove 21 covers a1 first regions 30, where a1 is 0 to 8, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, etc. That is, the number of first regions located on the first side of the first groove 21 and in contact with the first adhesive layer 81 is a1, in other words, the surface of the first functional layer 20 includes a third region 85 located on the first side of the first groove 21 and covered by the first adhesive layer 81, and the number of first regions 30 extending into the third region 85 is a1.

[0111] For example, a1=1 as shown in FIG.

[0112] Furthermore, the portion of the first adhesive layer 81 located on the surface of the first functional layer 20 on the second side of the first groove 21 covers a2 first regions 30, where a2 is 0 to 8. That is, the number of first regions 30 located on the second side of the first groove 21 and in contact with the first adhesive layer 81 is a2. In other words, the surface of the first functional layer 20 includes a fourth region 86 located on the second side of the first groove 21 and covered by the first adhesive layer 81, and the number of first regions 30 extending into the fourth region 86 is a2.

[0113] Illustratively, a2=1 as shown in FIG.

[0114] Further, the portion of the first adhesive layer 81 located on the surface of the first functional layer 20 on the third side of the first groove 21 contacts a3 first regions 30, where a3 is 0 to 40, for example, 0, 2, 5, 8, 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, etc. That is, the number of first regions 30 located on the third side of the first groove 21 and contacting the first adhesive layer 81 is a3. In other words, the surface of the first functional layer 20 includes a fifth region 87 located on the third side of the first groove 21 and covered by the first adhesive layer 81, and the number of first regions 30 extending into the fifth region 87 is a3.

[0115] As shown in FIGS. 11 and 12, a3 is also the sum of the first area 30 in contact with the first adhesive layer 81.

[0116] In one embodiment, all of the first regions 30 (a1) that extend into the third region 85 extend into the fifth region 87. All of the first regions 30 (a2) that extend into the fourth region 86 extend into the fifth region 87. The number of first regions 30 that extend into the fifth region 87 and contact the first groove 21 is a4. In this case, a3=a1+a2+a4.

[0117] Exemplarily, as shown in FIG. 11, a3=4, where a1=1, a2=1, and a4=2.

[0118] In one embodiment, the first adhesive layer 81 has a width w31 (which is also the width of the first functional layer 20 in the longitudinal direction of the third region 85) along the longitudinal direction of the first functional layer 20 at the portion located on the surface of the first functional layer 20 on the first side of the first groove 21, which is 1 mm to 5 mm, for example, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc.

[0119] Furthermore, the first adhesive layer 81 has a width w32 (which is also the width of the fourth region 86 along the longitudinal direction of the first functional layer 20) along the longitudinal direction of the first functional layer 20 at the portion located on the surface of the first functional layer 20 on the second side of the first groove 21 of 1 mm to 5 mm, for example, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc.

[0120] The width of the first adhesive layer 81 along the longitudinal direction of the first functional layer 20 is approximately equal to the sum of w31, the width of the first groove 21 along the longitudinal direction of the first functional layer 20, and w32.

[0121] In one embodiment, the opposing end edges of the first region 30 are flush with the opposing edges of the first functional layer 20. As shown in Figures 11 and 12, the length of any one of the first regions 30 in the width direction of the first functional layer 20 is equal to the length of the first functional layer 20 in which it is located, and for example, the length of the first region 30 located on both opposing sides (first side and second side) of the first groove 21 is equal to the width of the portions of the first functional layer 20 located on both opposing sides of the first groove 21.

[0122] The longitudinal direction of the first functional layer 20 is also the longitudinal direction of the first current collector 10, and the width direction of the first functional layer 20 is also the width direction of the first current collector 10. The width of the first current collector 10 is approximately equal to the maximum width of the first functional layer 20 (i.e., the width of the portions of the first functional layer 20 located on both opposing sides of the first groove 21 in Figures 11 and 12).

[0123] In one embodiment, as shown in FIG. 11, at least one end of the first current collector 10 may further be provided with a first bare foil region 11 where the first functional layer 20 is not provided.

[0124] A battery according to an embodiment of the present application includes a first plate, a separator, and a second plate that are stacked in sequence, the first plate including the plate described above, and the second plate having a polarity opposite to that of the first plate.

[0125] In one embodiment, the battery includes a cell, the cell including a first plate, a separator, and a second plate, which are stacked in sequence. The cell may be specifically a wound cell in which the first plate, the separator, and the second plate are stacked in sequence and then wound, and the wound cell may be formed by winding along the longitudinal direction of the first plate / separator / second plate. In the wound cell, each of the first plate, the separator, and the second plate has a bent portion and a straight portion connected to both ends of each bent portion, the direction from one bent portion to the other bent portion is parallel to the longitudinal direction of the wound cell, and the direction from one straight portion to the other straight portion is parallel to the width direction of the wound cell.

[0126] Here, the separator serves to isolate the first and second electrodes and to prevent short circuit between them. The thickness of the separator may be 5 to 16 μm, for example, 5 μm, 8 μm, 10 μm, 13 μm, 16 μm, etc. The separator may be a conventional separator in the art, for example, a coated separator in which a coating layer is applied to a substrate or a substrate.

[0127] In one embodiment, the second plate includes a second current collector and a second functional layer 92 provided on the surface of the second current collector. The second plate has opposite ends (referred to as the fifth end and the sixth end, respectively), and at least one end of the second plate has a second bare foil area 93 that is not provided with a coating layer. In addition to the second bare foil area 93, the remaining part of the second plate is provided with a second functional layer 92. The area where the second functional layer 92 and the second bare foil area 93 contact each other usually has an uneven structure. In order to avoid damaging the separator and improve the safety performance of the battery, a second adhesive layer 82 may be provided on at least one end of the second plate that is covered by the first plate. Here, the part of the second plate that is covered by the first plate is usually also the part of the second plate that is covered by the separator. The second functional layer 92 is an active material layer of the second plate.

[0128] 13, a second adhesive layer 82 is provided in a region of one end (fifth end) of the second plate that is covered by the first plate, and the number of first regions 30 of the first plate corresponding to the second adhesive layer 82 is x (0≦x≦20). x is, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20.

[0129] 11 and 12, the first plate has opposite ends (referred to as the third end and the fourth end, respectively), one of which (the third end) has a first end covering region 22. The first end covering region 22 corresponds to the position of the second adhesive layer 82 of the second plate, i.e., the first end covering region 22 and the second adhesive layer 82 are covered with each other (the projection of the second adhesive layer 82 on the first plate is approximately coincident with the first end covering region 22), and the width W4 of the first end covering region 22 in the longitudinal direction of the first plate / second plate is equal to the width W6 of the second adhesive layer 82 in the longitudinal direction of the first plate / second plate. There are x first regions 30 in the first end covering region 22.

[0130] In some embodiments, the width w6 of the second adhesive layer 82 in the longitudinal direction of the second plate is between 3 mm and 5 mm, for example, w6 is 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm.

[0131] Here, as shown in FIG. 13, the second adhesive layer 82 covers at least a portion of the second bare foil area 93 and extends from the second bare foil area 93 to the surface of the second functional layer 92.

[0132] 11 to 13, the other end (fourth end) of the first electrode plate has a second end covering region 23 that covers the other end (sixth end) of the second electrode plate. That is, the projection of the sixth end of the second electrode plate on the first electrode plate is located in the second end covering region 23 and does not exceed the second end covering region 23, and there is no bare foil region at the sixth end of the second electrode plate (that is, the outer edges of the second functional layer 92 and the second current collector are flush), so the second adhesive layer 82 does not need to be provided.

[0133] In some embodiments, the width w5 of the second end covering region 23 in the longitudinal direction of the first plate is 3 to 5 mm, for example, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc.

[0134] 13, a third adhesive layer is provided on the surface of the second electrode plate at a position corresponding to the first tab 91 / first groove 21 of the first electrode plate. The third adhesive layer covers the first groove 21 with a projection on the first electrode plate, which can further prevent lithium deposition in the negative electrode.

[0135] Here, the third adhesive layer has a first projection on the first plate covering at least one first region 30. The first projection, a portion located on the first side of the first groove 21, covers 0 to 8 first regions 30, and the number is, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, etc., and may or may not be equal to a1. The first projection, a portion located on the second side of the first groove 21, covers 0 to 8 first regions 30, and the number is, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, etc., and may or may not be equal to a2. The first projection, a portion located on the third side of the first groove 21, covers 0 to 40 first regions 30, and the number is, for example, 0, 2, 5, 8, 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, etc., and may or may not be equal to a3.

[0136] In one embodiment, the first projection may have a width of 1 mm to 5 mm along the longitudinal direction of the first functional layer 20 at a portion located on the first side of the first groove 21, for example, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc., which may or may not be equal to w31. The first projection may have a width of 3 mm to 5 mm along the longitudinal direction of the first functional layer 20 at a portion located on the second side of the first groove 21, for example, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc., which may or may not be equal to w32.

[0137] In one embodiment, the third adhesive layer may be a first projection on the first plate that covers or is covered by the first adhesive layer 81, where the two are, for example, congruent.

[0138] In one embodiment, a second tab is provided on the second plate, and the first tab 91 and the second tab do not coincide in the width direction of the cell, i.e., the projection of the first tab 91 perpendicular to the width direction of the cell and the projection of the second tab perpendicular to the width direction of the cell do not coincide.

[0139] In some embodiments, the second functional layer 92 is provided with a second groove 921 and a fourth adhesive layer 84 covering the second groove 921. The second tab is at least partially located within the second groove 921 and covered by the fourth adhesive layer 84 (i.e., the portion of the second tab located within the second groove 921 is covered by the second adhesive layer 82).

[0140] In one embodiment, the second groove 921 is a tab groove for providing a tab, and at least a part of the bottom surface of the second groove 921 is the surface of the second current collector (i.e., a part of the bottom surface of the second groove 921 exposes the second current collector). The second tab may be connected to the second current collector exposed at the bottom surface of the second groove 921, and more specifically, may be welded to the second current collector exposed at the bottom surface of the second groove 921.

[0141] Here, as shown in FIG. 13, the second plate may have a central tab mounting structure in which the second tab is provided in the middle rather than at the end.

[0142] In one embodiment, the second groove 921 is at least flanked on both sides by the second functional layer 92. In some embodiments, as shown in FIG. 13, in a plane perpendicular to the thickness direction of the second current collector, the second groove 921 has one side flush with one long side of the second current collector and the remaining side surrounded by the second functional layer 92, i.e., the second groove 921 has an opening toward one long side of the second current collector. After the second tab is provided, one end of the second tab may extend from the outer edge of the second current collector through the opening. Specifically, the second tab extends from the outer edge of the second current collector through the opening along its longitudinal direction. A portion of the second tab located within the second groove 921 (i.e., a portion not extending from the outer edge of the first current collector 10) is covered by the second adhesive layer 82. Here, the longitudinal direction of the second tab is parallel to the width direction of the second electrode plate.

[0143] As shown in FIG. 13, the second groove 921 has a rectangular shape when projected onto the second current collector, one short side of which is flush with one long side of the second current collector, and the remaining three sides of which are surrounded by the second functional layer.

[0144] In one embodiment, the fourth adhesive layer 84 extends to the surface of the second functional layer 92 around the second groove 921 and is adhered to the second functional layer 92 around the second groove 921 .

[0145] In one embodiment, the second groove 921 has a fourth side, a fifth side, and a sixth side, and the direction from the fourth side to the fifth side is parallel to the longitudinal direction of the second plate. The fourth adhesive layer 84 has a projection on the first plate covering at least one first region 30. The fourth adhesive layer 84 has a projection on the first plate located on the fourth side of the second groove covering 0 to 8 first regions 30, the number of which may be, for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8, and may be equal to or different from a1. The fourth adhesive layer 84 has a projection on the first plate located on the fifth side of the second groove covering 0 to 8 first regions 30, the number of which may be, for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8, and may be equal to or different from a2. The fourth adhesive layer 84 covers 0 to 40 first regions 30 in a projection on the first plate of the portion located on the sixth side of the second groove, and the number may be, for example, 0, 2, 5, 8, 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38 or 40, and may not be equal to a3.

[0146] In one embodiment, the width of the fourth adhesive layer 84 along the longitudinal direction of the second electrode plate at the portion located on the fourth side of the second groove may be 1 mm to 5 mm, for example, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm, and may or may not be equal to w31. The width of the fourth adhesive layer 84 along the longitudinal direction of the second electrode plate at the portion located on the fifth side of the second groove may be 3 mm to 5 mm, for example, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm, and may or may not be equal to w32.

[0147] In one embodiment, the second groove 921 may have parameters such as shape and dimensions that are the same as or different from the first groove 21, and the fourth adhesive layer 84 may have parameters such as shape and area that are the same as or different from the first adhesive layer 81.

[0148] The thickness of the first adhesive layer 81, the second adhesive layer 82, the third adhesive layer, and the fourth adhesive layer 84 may each be 10 μm to 16 μm, for example, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, etc., and specifically, may be adhesive paper.

[0149] In addition, when a certain adhesive layer (or its projection) as described above covers the first region 30, it means that in the longitudinal direction of the first functional layer 20, both opposing sides of the first region 30 covered by the adhesive layer are located within the projection of the adhesive layer on the surface of the first functional layer 20 (i.e., the first region 30 covered by the adhesive layer does not extend from the outer edge of the projection of the adhesive layer on the surface of the first functional layer 20), but in the width direction of the first functional layer 20, the first region 30 covered by the adhesive layer may be partially located within the projection of the adhesive layer on the surface of the first functional layer 20 and partially located outside the projection of the adhesive layer on the surface of the first functional layer 20, or entirely located within the projection of the adhesive layer on the surface of the first functional layer 20.

[0150] For example, as shown in Figures 11 and 12, the first adhesive layer 81 covers four first regions 30, and in the longitudinal direction of the first functional layer 20, both opposing sides of the four first regions 30 are located within the projection of the first adhesive layer 81 on the surface of the first functional layer 20, but in the width direction of the first functional layer 20, the four first regions 30 partially extend within the projection of the first adhesive layer 81 on the surface of the first functional layer 20, and partially are located outside the projection of the first adhesive layer 81 on the surface of the first functional layer 20.

[0151] The battery may include a lithium ion battery, and may be manufactured by a conventional method in the art, and the manufacturing process generally includes steps of winding, sealing, injection, aging, chemical formation, double sealing, sorting, packaging, etc. For example, a pouch-type lithium ion battery may be manufactured by stacking a first electrode plate, a separator, and a second electrode plate, and then winding them to form a bare cell, placing the bare cell in an exterior foil (e.g., aluminum plastic film), injecting an electrolyte into the cell, and further performing steps of vacuum sealing, standing, chemical formation (e.g., constant current charging at 0.1C to 4% SOC (state of charge), and further constant current charging at 0.2C to 10% SOC), shaping, etc.

[0152] In order to demonstrate that the improvement of the electrode plate according to the present application can improve the initial efficiency of the battery and improve the swelling effect of the battery, the following tests were carried out on the produced electrode plate.

[0153] (Test 1) <Surface Morphology Test for the First Region 30 and the Second Region 40> An image is taken with a scanning electron microscope (SEM) at a magnification of 500x to 1.0kx, and with reference to the 50x SEM image shown in FIG. 2, the widths of the first region 30 and the second region 40 are positioned and measured using a scale.

[0154] Here, the distance between adjacent second regions 40, i.e., the width of the first region 30, is the measured value at H1, H2, and H3 shown in the figure, where H1=537 μm, H2=372 μm, and H3=416 μm.

[0155] Here, the distance between adjacent first regions 30, that is, the width of the second region 40, is the measured value at H4 and H5 shown in the figure. H4=267 μm, H5=279 μm.

[0156] (Test 2) <Testing for elements in the first region 30 and the second region 40> Here, the electrode plate according to the embodiment of the present application is selected, and the position where the SEM collects the image is tested and analyzed by an energy dispersive spectrometer (abbreviated as EDS). Figure 3 shows an EDS area analysis diagram of an electron microscope image at 500 times. Figure 4 shows an EDS area analysis diagram of an electron microscope image at 500 times at the dotted line position within the dotted line frame in Figure 3.

[0157] The horizontal line AB shown in Fig. 5 indicates the position of the straight line path from the first region 30 to the second region 40, and the element distribution at the position of the horizontal line AB in Fig. 5 is tested by an energy dispersive X-ray analyzer (EDS). The measured SEM element content line analysis diagrams are shown in Figs. 6, 7 and 8.

[0158] FIG. 6 shows a distribution trend diagram of phosphorus element, in which the horizontal axis indicates position and the vertical axis indicates the phosphorus element content. As can be seen from FIG. 6, the phosphorus element content decreases from the first region 30 to the second region 40.

[0159] FIG. 7 shows a distribution trend diagram of elemental fluorine, where the horizontal axis indicates position and the vertical axis indicates the amount of elemental fluorine contained. As can be seen from FIG. 7, the amount of elemental fluorine decreases from the first region 30 to the second region 40.

[0160] FIG. 8 shows a distribution trend diagram of the oxygen element, where the horizontal axis indicates the position and the vertical axis indicates the oxygen element content. As can be seen from FIG. 8, the oxygen element content decreases from the first region 30 to the second region 40.

[0161] (Test 3) <Cycle test and expansion test> Below, cycle tests and expansion tests are carried out on the batteries of two comparative examples and two experimental examples. The batteries used in the two comparative examples and the batteries used in the two experimental examples differ only in that the batteries used in the two experimental examples use the electrode plate according to the present application as the negative electrode plate, while the battery used in the comparative examples uses a conventional negative electrode plate that does not contain metallic lithium.

[0162] The test process includes the following steps: In step 1, the battery is left to stand in a temperature environment of 5°C ± 2°C for 10 minutes. In step 2, the battery is discharged to the lower limit voltage at a battery discharge rate of 0.2C and then left to stand for 10 minutes. In step 3, charge the battery at a battery charging rate of 0.7C up to the upper limit voltage, stop at 0.05C, and leave it for 10 minutes. In step 4, the battery is discharged to the lower limit voltage at a battery discharge rate of 0.2C, and then an initial capacity test is performed. In step 5, the battery is left to stand for 10 minutes. In step 6, charge the battery at a battery charge rate of 3C to the upper voltage limit, stop at 0.05C, and test the battery thickness. In step 7, the battery is left to stand in a temperature environment of 25°C ± 2°C for 10 minutes. In step 8, the battery is discharged to the lower limit voltage at a battery discharge rate of 1C and then left to stand for 10 minutes. In step 9, charge the battery at a battery charging rate of 3C up to the upper limit voltage, stop at 0.05C, and let it sit for 10 minutes. In step 9, steps 8 and 9 are repeated for 1000 cycles, in which the thickness of the battery is tested in a fully charged state every 50 cycles from 0 to 200 cycles, and the thickness of the battery is tested in a fully charged state every 100 cycles from 200 to 1000 cycles. Furthermore, steps 3 and 4 are repeated in a temperature environment of 25°C to perform a capacity test, and after completing 1000 cycles, the thickness of the battery is detected in a fully charged state.

[0163] (Test 4) <Capacity test> Using batteries with the same target capacity, four experimental examples and one comparative example were processed to have different target capacities so as to have different lithium replenishment surface densities, and these batteries were placed in a constant temperature environment of 25°C, charged at a constant current and constant voltage to 4.48V at a battery charge rate of 1C, then charged at a constant voltage to stop at 0.05C, left to stand for 5 minutes, and then discharged to 3V at a battery discharge rate of 0.2C, and the capacity data at 3V were compared. The results are shown in Tables 1 to 4 below.

[0164] [Table 1]

[0165] [Table 2]

[0166] [Table 3]

[0167] [Table 4]

[0168] As can be intuitively seen from Tables 1 to 4, the initial efficiencies of the batteries according to the experimental examples all exceed the initial efficiencies of the batteries according to the corresponding comparative examples, proving that the present application can significantly improve the problem of low initial efficiencies of lithium ion batteries.

[0169] In Experimental Examples 1 to 4, the 3V capacity was significantly improved compared to Comparative Example 1. The batteries with different target capacities used metallic lithium with different areal densities in the first region 30 of the electrode plate, and all of them improved their battery capacities and reached the target capacity values.

[0170] The detection results of step 9 are shown in Fig. 10, where the horizontal axis represents the number of charge / discharge cycles and the vertical axis represents the expansion rate. As shown in Fig. 10, the battery according to the present application has a lower expansion rate in a fully charged state than the conventional battery, and the improvement effect against battery expansion is remarkable.

[0171] FIG. 9 is a comparison diagram of cycle performance curves of the battery according to the present application and a conventional battery, in which the horizontal axis represents the number of charge / discharge cycles and the vertical axis represents the capacity retention rate of the battery. As shown in FIG. 9, the capacity of the battery according to the present application decreased to 80% after completing 450 charge / discharge cycles, while the capacity of the conventional battery decreased to 80% after completing 350 charge / discharge cycles. Therefore, the battery according to the present application has improved cycle performance by about 100 charge / discharge cycles, and the capacity retention rate of the battery is improved by about 5% to 15% accordingly. This proves that the present application significantly improves the capacity and cycle performance of the battery through improvements.

[0172] In addition, in the description of this application, the orientations or positional relationships indicated by terms such as "center," "length," "width," "thickness," "top end," "bottom end," "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "inner," "outer," "axial direction," "circumferential direction," and the like are shown based on the drawings and are merely intended to conveniently and simply explain this application. They do not indicate or imply that such positions or elements necessarily have a specific orientation or are configured and operated in a specific orientation, and therefore should not be understood as limitations on this application.

[0173] Moreover, the terms "first", "second", etc. are merely for explanatory purposes and should not be understood as indicating or implying a relative importance or implying the number of technical configurations involved. Thus, a configuration defined by "first" or "second" can explicitly or implicitly include one or more of the configurations. In the description of this application, "multiple" means at least two, e.g., two, three, etc., unless otherwise specified. [Explanation of symbols]

[0174] 10 First current collector 11 First bare foil region 20 First functional layer 21 First concave groove 22 First end covering region 23 Second end covering region 30 First region 40 Second region 60 Transition region 80 Lithium ribbon 81 First adhesive layer 82 Second adhesive layer 84 Fourth adhesive layer 85 Third region 86 Fourth region 87 Fifth region 91 First tab 92 Second functional layer 921 Second concave groove 93 Second bare foil region

Claims

1. A plate, The present invention includes a first current collector (10) and a first functional layer (20) provided on at least one surface of the first current collector (10), A plurality of first regions (30) and a plurality of second regions (40) are distributed at a distance from each other on the surface of the first functional layer (20); In the first region (30), the content ratio of oxygen element to silicon element in the first functional layer (20) is greater than 4:1; The electrode plate characterized by the above.

2. The first region (30) contains carbon, oxygen, fluorine, phosphorus and silicon elements.

2. The electrode plate according to claim 1 .

3. In the first region (30), the content ratio of fluorine element to phosphorus element in the first functional layer (20) is greater than 7:1; 3. The electrode plate according to claim 2.

4. The second region (40) contains carbon, oxygen, fluorine, phosphorus and silicon elements.

2. The electrode plate according to claim 1 .

5. In the second region (40), the content ratio S1:S2 of oxygen element to silicon element in the first functional layer (20) satisfies 2:1≦S1:S2≦4:

1.

5. The electrode plate according to claim 4.

6. In the second region (40), the content ratio S3:S4 of fluorine element to phosphorus element in the first functional layer (20) satisfies 6:1≦S3:S4≦7:

1.

6. The electrode plate according to claim 5.

7. The content of fluorine element in the first functional layer (20) located in the first region (30) is greater than the content of fluorine element in the first functional layer (20) located in the second region (40); The electrode plate according to any one of claims 1 to 6.

8. The content of phosphorus element in the first functional layer (20) located in the first region (30) is greater than the content of phosphorus element in the first functional layer (20) located in the first region (30); The electrode plate according to any one of claims 1 to 6.

9. The content of oxygen element in the first functional layer (20) located in the first region (30) is greater than the content of oxygen element in the first functional layer (20) located in the second region (40); The electrode plate according to any one of claims 1 to 6.

10. the width of said second region (40) is between 0 μm and 4 mm; and / or The width of the first region (30) is 100 μm to 4 mm. The electrode plate according to any one of claims 1 to 6.

11. The first functional layer (20) contains active material particles, The active material particles include at least one of a silicon material and a silicon oxide material, and a carbon material, and the mass of the silicon material and / or the silicon oxide material accounts for 7% to 50% of the total mass of the active material particles, or the active material particles include a carbon material and graphite; or The active material particles contain at least one of a silicon material and a silicon oxide material, and a carbon material, and the mass of the silicon material and / or the silicon oxide material accounts for 7% to 50% of the total mass of the active material particles. The electrode plate according to any one of claims 1 to 6.

12. The extension direction of the first region (30) forms a first included angle with the width direction of the first functional layer (20), and the first included angle is in the range of 0° to 45°; and / or the ratio of the total area of ​​the plurality of first regions (30) to the total area of ​​the second regions (40) is between 0.7:1 and 3:1; and / or With respect to the surface of the first current collector (10), the portion of the first region (30) farthest from the first current collector (10) is higher than the portion of the second region (40), and the height difference between the portion of the first region (30) farthest from the first current collector (10) and the portion of the second region (40) farthest from the first current collector (10) is 0.1 μm to 8 μm.

2. The electrode plate according to claim 1 .

13. The electrode plate further includes a first tab (91) and a first adhesive layer (81) formed on a surface of the first functional layer (20); A first groove (21) is provided in the first functional layer (20), and at least a portion of the first tab (91) is located in the first groove (21) and covered by the first adhesive layer (81); The first adhesive layer (81) covers at least one of the first regions (30); 13. The electrode plate according to claim 12.

14. The first groove (21) has a first side, a second side, and a third side, and the direction from the first side to the second side is parallel to the longitudinal direction of the first functional layer (20); The first adhesive layer (81) has a portion located on the surface of the first functional layer (20) on the first side of the first groove (21) covering 0 to 8 of the first regions (30), and / or The first adhesive layer (81) has a portion located on the surface of the first functional layer (20) on the second side of the first groove (21) covering 0 to 8 of the first regions (30), and / or The first adhesive layer (81) has a portion located on the surface of the first functional layer (20) on the third side of the first groove (21) covering 0 to 40 of the first regions (30), and / or The first adhesive layer (81) has a width of 1 mm to 5 mm in the longitudinal direction of the first functional layer (20) at a portion located on the surface of the first functional layer (20) on the first side of the first groove (21), and / or The first adhesive layer (81) has a width of 1 mm to 5 mm in the longitudinal direction of the first functional layer (20) at a portion located on the surface of the first functional layer (20) on the second side of the first groove (21).

14. The electrode plate according to claim 13.

15. A battery, The fuel cell includes a sealed case and a cell located inside the sealed case, The cell includes a first plate, which is the plate according to any one of claims 1 to 14, and a second plate having a polarity opposite to that of the first plate. A battery characterized in that

16. A second adhesive layer (82) is provided on one end of the second plate in the area covered by the first plate, the number of the first regions (30) in the first plate corresponding to the second adhesive layer (82) is between 0 and 20; and / or the second plate includes a second current collector and a second functional layer (92) provided on a surface of the second current collector, a second bare foil area (93) on which the second functional layer (92) is not provided is present at one end of the second plate, and the second adhesive layer (82) covers at least a portion of the second bare foil area (93) and extends from the second bare foil area (93) to the surface of the second functional layer (92); and / or The second adhesive layer (82) has a width of 3 mm to 5 mm in the longitudinal direction of the second electrode plate; 16. The battery of claim 15.

17. The first functional layer (20) is provided with a first groove (21), and a third adhesive layer is provided on the surface of the second electrode plate at a position corresponding to the position of the first groove (21), and / or The second plate includes a second current collector and a second functional layer (92) provided on a surface of the second current collector, the second functional layer (92) is provided with a second groove (921) and a fourth adhesive layer (84) covering the second groove (921), and the second plate is provided with a second tab, at least a portion of the second tab being located within the second groove (921) and covered by the fourth adhesive layer (84).

17. The battery of claim 16.

18. the first groove (21) has a first side, a second side and a third side, the third adhesive layer has a first projection on the first plate covering at least one of the first regions (30), and the first projection satisfies that the portion located on the first side of the first groove (21) covers 0 to 8 of the first regions (30); and / or The first projection has a portion located on the second side of the first groove (21) covering 0 to 8 of the first regions (30); and / or The first projection has a portion located on the third side of the first groove (21) covering 0 to 40 of the first regions (30); and / or the second groove (921) has a fourth side, a fifth side and a sixth side, the fourth adhesive layer (84) has a projection on the first plate covering at least one of the first regions (30), and the fourth adhesive layer (84) satisfies the following: the projection on the first plate of the portion located on the fourth side of the second groove (921) covers 0 to 8 of the first regions (30); and / or The fourth adhesive layer (84) covers a portion of the first region (30) located on a fifth side of the second groove (921) that has a projection of 0 to 8 on the first plate, and / or The fourth adhesive layer (84) covers the first region (30) having a projection of 0 to 40 on the first plate, the portion being located on the sixth side of the second groove (921); 20. The battery of claim 17 .

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