Battery negative plate and battery

Abstract

The utility model provides a battery negative pole piece and battery, battery negative pole piece includes current collector and active layer, active layer is coated on current collector at least one side surface, on the active layer is equipped with a plurality of groove structure along the length direction of current collector, groove structure extends along the width direction of current collector, and the groove structure is equipped with the groove structure. The active layer is divided into a plurality of areas by the plurality of groove structures along the length direction of the current collector, and each area is provided with a plurality of hole structures. According to the battery negative plate, the hole structures and the groove structures which are sequentially and alternately arranged in the length direction of the current collector are adopted, the liquid injection time of the battery is shortened, meanwhile, the liquid retention amount of electrolyte is increased, the wettability of the electrode is improved, the cycle life is prolonged, the service life of the battery is prolonged, and the performance stability of the battery is improved; and the problem that the battery performance is influenced due to poor wettability of the battery negative plate in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery negative plate and a battery. BACKGROUND

[0002] With the development of new energy technology, battery technology is also constantly improving, especially lithium ion batteries are widely used in new energy vehicles and other electric tools.

[0003] Currently, in the field of lithium ion battery technology, the wettability and liquid retention capacity of electrolyte are one of the key factors affecting the performance and life of the battery. In the charge and discharge cycle of the battery, the uniformity and durability of the electrolyte distribution are crucial to maintaining the stability of the battery and prolonging its service life. The loss of electrolyte will cause the internal resistance of the battery to increase, the capacity to decrease, and even may cause safety problems.

[0004] In the existing lithium ion battery technology, the negative electrode coating surface density and the compaction density are constantly pursuing the limit design, after low temperature charging or large rate charging or long term cycling, the negative plate is easy to cause lithium precipitation or purple(black) spot due to lack of electrolyte, etc., thereby causing the battery low temperature or large rate charging performance not to meet the standard, the cycle life is greatly reduced, and even causes the battery safety problem.

[0005] From the above, the current battery negative plate has the problem of poor wettability affecting the performance of the battery. CONTENT OF THE UTILITY MODEL

[0006] The main purpose of the utility model is to provide a battery negative plate and a battery, so as to solve the problem of poor wettability of the battery negative plate in the prior art affecting the performance of the battery.

[0007] In order to achieve the above purpose, according to one aspect of the utility model, a battery negative plate is provided, which comprises a current collector and an active layer, the active layer is coated on the surface of at least one side of the current collector, the active layer has a plurality of groove structures arranged in sequence and spaced apart along the length direction of the current collector, the groove structures are arranged along the width direction of the current collector, and the plurality of groove structures along the length direction of the current collector separate the active layer into a plurality of regions, each region has a plurality of hole structures.

[0008] Further, the plurality of groove structures are arranged equidistantly and parallelly along the length direction of the current collector.

[0009] Further, the total thickness L of the current collector and the active layer satisfies 60-200 mu m, the groove depth H of the groove structure is 10%-70% of the thickness of the active layer; and / or along the length direction of the current collector, the distance W between the opposite two groove inner walls of the groove structure satisfies 20 mu m<=W<=120 mu m; and / or along the length direction of the current collector, the spacing S between the adjacent two groove structures satisfies 0.5 mm<=S<=5 mm.

[0010] Further, the extension length of the groove structure along the width direction of the current collector is equal to the width of the active layer; or along the width direction of the current collector, the distance T between the two ends of the groove structure and the edges of the active layer satisfies 0 mm

[0011] Further, the hole structures are arranged at equal intervals along the length and width directions of the current collector.

[0012] Further, the hole depth h of the hole structure satisfies 5 mu m<=h<=50 mu m; and / or the diameter D of the hole structure satisfies 10 mu m<=D<=100 mu m; and / or the spacing L between the adjacent two hole structures satisfies 50 mu m<=L<=300 mu m.

[0013] Further, the opening of the hole structure is circular or elliptical.

[0014] Further, along the length direction of the current collector, the spacing between the adjacent two groove structures is S, the spacing between the adjacent two hole structures is L, and the multiple hole structures on each region form n rows, n=ROUND(S*1000 / L,0)-1.

[0015] Further, the groove structure and the hole structure are processed by laser.

[0016] Further, the active layer is coated on the surfaces of the two sides of the current collector, and the groove structures on the two sides of the current collector are symmetrically or staggeredly arranged along the length direction of the current collector.

[0017] According to another aspect of the utility model, a kind of battery is provided, battery includes electric core and shell, electric core includes positive plate, electrolyte, diaphragm and negative plate, negative plate is above-mentioned battery negative plate, electric core is arranged in the inside of shell.

[0018] The technical scheme of the utility model is applied, the battery negative plate of the application adopts hole structure and groove structure which are sequentially and alternately arranged along the length direction of current collector, shortens the liquid injection time of battery, increases the liquid retention of electrolyte, improves the wettability of electrode, and is beneficial to the extension of cycle life, improves the service life and performance stability of battery.

[0019] The processing on the active layer forms corresponding groove structures and hole structures, which are beneficial to the surface treatment of the active layer, the groove structures have the functions of liquid retention and liquid guiding, the hole structures have the function of liquid retention, the groove structures and the hole structures effectively improve the liquid retention performance and wettability of the pole piece, and the alternately arranged groove structures and hole structures further improve the uniformity of electrolyte penetration, which is beneficial to ensuring the stability of the battery performance. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which form a part of the specification, are included to provide a further understanding of the application and are incorporated herein in conjunction with the description of the application. The embodiments of the present application, illustrated in the drawings and described below, serve to explain the present application and do not limit the present application in any way. In the drawings:

[0021] Figure 1 One of the top views of the battery negative pole piece of the present application is shown;

[0022] Figure 2 Another top view of the battery negative pole piece of the present application is shown.

[0023] Among them, the above-mentioned drawings include the following reference signs:

[0024] 10, current collector; 20, active layer; 210, area; 30, groove structure; 40, hole structure. DETAILED DESCRIPTION

[0025] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0026] It should be noted that, unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0027] In the present application, unless otherwise specified, the orientation words such as "up, down, top, bottom" are generally directed to the direction shown in the drawings, or are directed to the vertical, perpendicular or gravity direction of the components themselves; similarly, for the convenience of understanding and description, "inner, outer" refers to the inner and outer relative to the contour of each component itself, but the above orientation words are not used to limit the present application.

[0028] In order to solve the problem that the battery negative pole piece in the prior art has poor wettability, which affects the performance of the battery, the present application provides a battery, which comprises a battery cell and a shell, the battery cell is arranged in the interior of the shell, wherein the battery cell comprises a positive pole piece, an electrolyte, a separator and a negative pole piece, the negative pole piece is the battery negative pole piece of the present application.

[0029] Specifically, the structure of the battery negative plate inside the battery improves the wettability with the electrolyte, effectively improving the performance of the battery.

[0030] The battery is a lithium battery.

[0031] As shown in Figure 1 and Figure 2 , the battery negative plate includes a current collector 10 and an active layer 20, the active layer 20 is coated on at least one side of the surface of the current collector 10, the active layer 20 has a plurality of groove structures 30 arranged in sequence and spaced apart along the length direction of the current collector 10, the groove structure 30 is arranged along the width direction of the current collector 10, and the plurality of groove structures 30 along the length direction of the current collector 10 separates the active layer 20 into a plurality of regions 210, and each region 210 has a plurality of hole structures 40.

[0032] The groove structure 30 extends along the width direction of the current collector 10, and the groove structure 30 is provided in plurality, the plurality of groove structures 30 are arranged in sequence along the length direction of the current collector 10 to form a setting region 210 of the hole structure 40 between the adjacent two groove structures 30, and the plurality of hole structures 40 are arranged inside the region 210.

[0033] In this embodiment, the current collector 10 is a copper foil or a carbon-coated copper foil, and the active layer 20 is arranged on the surface of the current collector 10. The active layer 20 not only has the effect of forming a gap in the active layer 20 for the flow of electrolyte, but also has the effect of improving the strength of the current collector 10 by arranging the active layer 20 on the side surface of the current collector 10.

[0034] When it is a carbon-coated copper foil, the thickness of the copper foil is 3-12μm, and the thickness of the carbon-coated layer of the carbon-coated copper foil is 0.2-2μm.

[0035] It should be noted that the active layer 20 of the present application is a coating layer containing active substances, which can be directly coated on the copper foil or on the copper foil with a carbon-coated layer.

[0036] In this embodiment, the length direction of the current collector 10 is the X direction as shown in Figure 1 , and the width direction of the current collector 10 is the Y direction as shown in Figure 1 . It can be understood that the length and width of the current collector 10 in the present application are not limited by the position of placement.

[0037] In this embodiment, the groove structure 30 and the hole structure 40 are processed by laser, that is, the groove is engraved by laser, and the hole is made by laser. The application of laser processing technology not only realizes the high-precision manufacturing of the groove structure 30 and the hole structure 40, but also can be flexibly adjusted according to different battery design requirements, improves the flexibility and efficiency of battery manufacturing, and reduces the production cost.

[0038] Specifically, the negative electrode sheet of the battery in this application adopts a hole structure 40 and a groove structure 30 arranged alternately along the length direction of the current collector 10, which shortens the electrolyte injection time of the battery, increases the electrolyte retention capacity, improves the wettability of the electrode, and is conducive to extending the cycle life, thereby improving the battery's service life and performance stability.

[0039] This application processes the active layer 20 to form corresponding groove structures 30 and pore structures 40, which facilitates the surface treatment of the active layer 20. The groove structure 30 has the function of retaining and guiding the liquid, and the pore structure 40 has the function of retaining the liquid. The groove structure 30 and pore structure 40 effectively improve the liquid retention performance and wettability of the electrode. In particular, the alternating arrangement of the groove structure 30 and pore structure 40 further improves the uniformity of electrolyte penetration, which is conducive to ensuring the stability of battery performance.

[0040] like Figure 1 As shown, multiple groove structures 30 are arranged at equal intervals and in parallel along the length direction of the current collector 10.

[0041] The multiple slot structures 30 are arranged at equal intervals, which helps to achieve consistency in liquid retention in area 210. At the same time, the multiple slot structures 30 are arranged in parallel, which helps to assist in the later winding to form the battery cell, facilitates bending, and helps to improve winding efficiency, thereby improving the production efficiency of the battery cell.

[0042] In this embodiment, the total thickness L of the current collector 10 and the active layer 20 satisfies 60μm≤L≤200μm. Specifically, L can be 60μm, 80μm, 100μm, 120μm, 140μm, 160μm, 180μm, 200μm, etc., where the thickness of the current collector 10 is 6μm.

[0043] In this embodiment, the groove depth H of the groove structure 30 is 10%-70% of the thickness of the active layer 20. If the groove depth of the groove structure 30 is too large, it will affect the strength of the electrode sheet. If the groove depth of the groove structure 30 is too small, it will affect the liquid retention effect and wettability.

[0044] In this application, the groove depth H of the groove structure 30 satisfies 3μm≤H≤30μm.

[0045] In this embodiment, along the length direction of the current collector 10, the distance W between the two opposing inner walls of the groove structure 30 satisfies 20μm≤W≤120μm. The two opposing inner walls of the groove form the groove width. If the groove width is too wide, it will affect the strength of the electrode. If the groove width of the groove structure 30 is too small, it will affect the liquid retention effect and wettability.

[0046] In the embodiment, the distance S between the two adjacent groove structures 30 along the length direction of the current collector 10 satisfies 0.5mm≤S≤5mm. If the distance between the two groove structures 30 is too large, the liquid retention effect and the wettability are not good, and if the distance between the two groove structures 30 is too small, the strength of the pole piece is affected. The parameters of the groove structure 30 of the application optimize the permeability of the electrolyte, and at the same time, the mechanical strength of the pole piece is strengthened, and the stable operation of the battery is ensured.

[0047] In one of the specific embodiments of the embodiment, as shown in Figure 1 the extension length of the groove structure 30 along the width direction of the current collector 10 is equal to the width of the active layer 20.

[0048] In one of the specific embodiments of the embodiment, as shown in Figure 2 the distance T between the two ends of the groove structure 30 and the edges of the active layer 20 along the width direction of the current collector 10 satisfies 0mm<T≤8mm.

[0049] The distance H between the two ends of the hole structure 40 and the edges of the active layer 20 also satisfies 0mm<H≤8mm, and specifically, H is the distance between the hole center of the hole structure 40 and the edge of the active layer 20.

[0050] The groove structure 30 is beneficial to improve the flow efficiency of the electrolyte, so that the electrolyte flows on the surface, and then the wettability of the entire negative pole piece of the battery is improved.

[0051] In the embodiment, a plurality of hole structures 40 are arranged in each region 210, and the plurality of hole structures 40 are arranged at equal intervals along the length and width directions of the current collector 10. The equal interval arrangement of the hole structure 40 is beneficial to improve the uniformity of the permeability, and at the same time, the plurality of interval arranged hole structures 40 have the liquid retention effect, and the arrangement of the hole structure 40 does not affect the strength of the pole piece.

[0052] In the embodiment, the hole depth h of the hole structure 40 satisfies 5μm≤h≤50μm, the diameter D of the hole structure 40 satisfies 10μm≤D≤100μm, and the distance L between the two adjacent hole structures 40 satisfies 50μm≤L≤300μm.

[0053] In the embodiment, the hole depth, diameter and hole distance of the hole structure 40 can be adaptively arranged according to the size of the current collector 10. If the hole depth and diameter are too large, the strength of the pole piece is affected, if the hole depth and diameter are too small, the liquid retention capacity and wettability are affected, if the hole distance is too large, the liquid retention capacity is affected, and if the hole distance is too small, the strength of the pole piece is affected.

[0054] In the embodiment, the opening of the hole structure 40 is circular or elliptical, and the specific shape of the hole structure 40 can be adaptively set as required.

[0055] In one specific embodiment, part of the holes are circular openings, and the other part are elliptical openings.

[0056] In the embodiment, the distance between the two adjacent groove structures 30 is S, the distance between the two adjacent hole structures 40 is L, and the plurality of hole structures 40 on each region 210 are formed in n rows, n = ROUND(S*1000 / L, 0)-1. This precise layout design can maximize the permeation efficiency and distribution uniformity of the electrolyte while maintaining the structural stability of the negative electrode sheet.

[0057] In the embodiment, the number of rows formed by the hole structure 40 is adaptively set according to the setting of the hole distance and the groove distance.

[0058] In the embodiment, when the current collector 10 is a carbon-coated copper foil, the thickness of the copper foil is 3-12 μm, and the thickness of the carbon-coated layer of the carbon-coated copper foil is 0.2-2 μm.

[0059] In the embodiment, the active layer 20 includes a negative electrode active material, a conductive agent, a thickening agent, and a binder. The negative electrode active material includes one or two of graphite, hard carbon, silicon-carbon, and silicon-oxygen material; the conductive agent includes one, two, or three of conductive carbon black, conductive graphite, single-walled carbon nanotubes, multi-walled carbon nanotubes, graphene, and conductive carbon fiber; the thickening agent includes one or two of sodium carboxymethyl cellulose and acrylic derivative multi-copolymer; and the binder includes one or two of a butylphenyl binder or a benzene-propyl binder or an acrylic derivative multi-copolymer.

[0060] In the embodiment, the active layer 20 can be a single-layer structure or a multi-layer structure.

[0061] In the embodiment, the coating form includes continuous coating or discontinuous coating.

[0062] In the embodiment, the surface laser groove scribing and laser hole forming of the battery negative electrode sheet are performed after the battery negative electrode is coated or after the negative electrode is rolled.

[0063] In the embodiment, the current collector 10 is formed with the active layer 20 on both sides in the thickness direction.

[0064] Specifically, by arranging the active layer 20 on both sides of the current collector 10, the wettability and liquid retention effect of the electrolyte can be further improved, and better protection effect can be achieved.

[0065] In one specific embodiment of the present embodiment, the groove structures 30 on both sides of the current collector 10 are symmetrically arranged along the thickness direction of the current collector 10.

[0066] The symmetrically arranged groove structures 30 are beneficial to improve the flow efficiency of the electrolyte, thereby accelerating the realization of the infiltration efficiency of the electrolyte and improving the liquid retention effect.

[0067] In the present embodiment, the groove structures 30 and the hole structures 40 on both sides of the current collector 10 are symmetrically arranged.

[0068] In another specific embodiment of the present embodiment, the current collector 10 is provided with the active layer 20 on both sides along the thickness direction of the current collector 10, and the groove structures 30 on the active layers 20 on both sides are staggered along the length direction of the current collector 10.

[0069] The staggered arrangement of the groove structures 30 on both sides is beneficial to ensure the structural strength of the battery negative plate, and also has good liquid retention capacity and infiltration effect.

[0070] In the present embodiment, the groove structures 30 and the hole structures 40 on both sides of the current collector 10 have staggered regions along the length direction of the current collector 10, that is, intermittent coating.

[0071] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0072] The battery negative plate of the present application adopts the hole structures 40 and the groove structures 30 alternately arranged along the length direction of the current collector 10, which shortens the liquid injection time of the battery, increases the liquid retention amount of the electrolyte, improves the wettability of the electrode, is beneficial to the prolongation of the cycle life, and improves the service life and the stability of the performance of the battery.

[0073] The present application forms the corresponding groove structures 30 and hole structures 40 on the active layer 20, which is beneficial to the surface treatment of the active layer 20. The groove structures 30 have the functions of liquid retention and liquid guiding, the hole structures 40 have the function of liquid retention, and the groove structures 30 and the hole structures 40 effectively improve the liquid retention performance and the wettability of the plate. Especially, the arrangement of the alternately arranged groove structures 30 and hole structures 40 further improves the uniformity of the electrolyte penetration, which is beneficial to ensuring the stability of the battery performance.

[0074] Obviously, the above-described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0075] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, as the scope of the exemplary embodiments of this application is intended to be broader than the specific embodiments described herein. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, devices, components and / or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, operations, devices, components and / or combinations thereof.

[0076] It should be noted that the terms "first", "second", and the like, used in the specification and in the claims of the application, as well as above-described figures, are used to distinguish similar objects and are not necessarily used to describe a specific sequence or order. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in an order other than that illustrated or described herein.

[0077] The above only the preferred embodiment of the present application has, and does not limit the present application, for those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery negative electrode sheet, characterized by, The battery negative electrode sheet comprises: a current collector (10); an active layer (20) coated on at least one surface of the current collector (10), the active layer (20) having a plurality of groove structures (30) arranged in sequence and at intervals along the length direction of the current collector (10), the groove structures (30) extending along the width direction of the current collector (10), and the plurality of groove structures (30) separating the active layer (20) into a plurality of regions (210), each of the regions (210) having a plurality of hole structures (40).

2. The battery negative electrode sheet according to claim 1, characterized by, The plurality of groove structures (30) are arranged in sequence and at intervals along the length direction of the current collector (10).

3. The battery negative electrode sheet according to claim 1, characterized by, The total thickness L of the current collector (10) and the active layer (20) satisfies 60 μm≤L≤200 μm, the groove depth H of the groove structure (30) is 10%-70% of the thickness of the active layer (20); and / or the distance W between the inner walls of the two opposite grooves of the groove structure (30) along the length direction of the current collector (10) satisfies 20 μm≤W≤120 μm; and / or the distance S between the two adjacent groove structures (30) along the length direction of the current collector (10) satisfies 0.5 mm≤S≤5 mm.

4. The battery negative electrode sheet according to claim 1, wherein the extension length of the groove structure (30) along the width direction of the current collector (10) is equal to the width of the active layer (20); or the distance T between the two ends of the groove structure (30) and the edges of the active layer (20) along the width direction of the current collector (10) satisfies 0 mm<T≤8 mm.

5. The battery negative electrode sheet according to claim 1, characterized by, The plurality of hole structures (40) are arranged in sequence and at intervals along the length and width directions of the current collector (10).

6. The battery negative electrode sheet according to claim 5, wherein the hole depth h of the hole structure (40) satisfies 5 μm≤h≤50 μm; and / or the diameter D of the hole structure (40) satisfies 10 μm≤D≤100 μm; and / or the distance L between the two adjacent hole structures (40) satisfies 50 μm≤L≤300 μm.

7. The battery negative electrode sheet according to claim 1, characterized by, The opening of the hole structure (40) is circular or elliptical.

8. The battery negative electrode sheet according to claim 1, wherein The distance between two adjacent groove structures (30) along the length direction of the current collector (10) is S, the distance between two adjacent hole structures (40) is L, a plurality of hole structures (40) on each region (210) are formed with n rows, n ＝ ROUND(S*1000 / L,0)-1.

9. The battery negative electrode sheet according to any one of claims 1 to 8, characterized by, the groove structure (30) and the hole structure (40) are processed by laser.

10. The battery negative electrode sheet according to any one of claims 1 to 8, characterized by, The active layer (20) is coated on the surfaces of both sides of the current collector (10), and the groove structures (30) on both sides of the current collector (10) are symmetrically or staggeredly arranged along the length direction of the current collector (10).

11. A battery, characterized by The battery comprises: an electric core comprising a positive electrode sheet, an electrolyte, a separator and a negative electrode sheet, the negative electrode sheet being the battery negative electrode sheet according to any one of claims 1 to 10; a shell, and the electric core is arranged inside the shell.

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