Battery pole piece and battery pole group

Abstract

The utility model relates to the technical field of batteries, in particular to a battery pole piece and a battery pole group, the battery pole piece comprises a current collector, an active substance part and a ceramic coating part, the current collector comprises a tab and a substrate which are connected with each other, the edge of the substrate is provided with a ceramic coating area, and the part, except the ceramic coating area, of the substrate is a material coating area. Wherein the active substance part is fully coated on the material coating area, and the ceramic coating part is fully coated on the ceramic coating area. According to the battery pole piece and the battery pole group provided by the invention, uneven edges or tiny bulges caused by working procedures such as cutting and stamping can be effectively coated through the ceramic coating part, so that burrs on the pole piece are prevented from possibly puncturing a diaphragm; and lithium ions are effectively prevented from being deposited in the edge area of the pole piece, and the influence of lithium dendrites on the battery performance is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery pole piece and a battery pole group. BACKGROUND

[0002] In the manufacturing process of a battery pole piece (such as a positive or negative material), due to cutting, stamping and other processes, the edge is uneven or small protrusions appear. The burrs on the pole piece can pierce the separator, causing internal short circuit, which may cause the battery to explode or catch fire. The existence of burrs increases the internal resistance of the battery, thereby affecting the overall performance of the battery. The burrs may continue to grow during the charging and discharging process, further damaging the performance of the battery.

[0003] In addition, during the charging and discharging process of the battery, lithium ions are excessively deposited in the edge region of the pole piece, which is prone to form metal lithium. The precipitated metal lithium cannot participate in the charging and discharging reaction again, not only causing the effective capacity of the battery to decrease, but also the deposition of metal lithium may form lithium dendrites, penetrate the separator and cause internal short circuit, leading to thermal runaway and even explosion of the battery. The lithium precipitation phenomenon will accelerate the aging of the battery and shorten its service life. CONTENT OF THE UTILITY MODEL

[0004] The purpose of the present application is to provide a battery pole piece and a battery pole group to solve the problem of uneven edges or small protrusions caused by cutting, stamping and other processes in the prior art. The burrs on the pole piece can pierce the separator, causing internal short circuit, which may cause the battery to explode or catch fire. The existence of burrs increases the internal resistance of the battery, thereby affecting the overall performance of the battery. The burrs may continue to grow during the charging and discharging process, further damaging the performance of the battery. In addition, during the charging and discharging process of the battery, lithium ions are excessively deposited in the edge region of the pole piece, which is prone to form metal lithium. The precipitated metal lithium cannot participate in the charging and discharging reaction again, not only causing the effective capacity of the battery to decrease, but also the deposition of metal lithium may form lithium dendrites, penetrate the separator and cause internal short circuit, leading to thermal runaway and even explosion of the battery. The lithium precipitation phenomenon will accelerate the aging of the battery and shorten its service life.

[0005] According to a first aspect of the present application, a battery pole piece is provided, comprising a current collector, an active material part and a ceramic coating part, the current collector comprising a tab and a base connected to each other, an edge of the base is provided with a ceramic coating area, and a part of the base other than the ceramic coating area is a material coating area;

[0006] The active material part is coated on the material coating area, and the ceramic coating part is coated on the ceramic coating area.

[0007] Preferably, the base is rectangular, and the tab is connected to a first side of the base.

[0008] At least one part of the ceramic coating region is arranged along an edge of the first side.

[0009] Preferably, the second side of the substrate is arranged opposite to the first side, and at least another part of the ceramic coating region is arranged along an edge of the second side.

[0010] Preferably, the third side and the fourth side of the substrate are respectively arranged adjacent to the first side, and at least still another part of the ceramic coating region is respectively arranged along an edge of the third side and an edge of the fourth side.

[0011] Preferably, in a direction perpendicular to the substrate, the size of the active material part and the size of the ceramic coating part are both equal to a predetermined thickness H.

[0012] Preferably, 30 μm≤H≤200 μm, so as to ensure that the ceramic coating part can completely wrap the edge of the above-mentioned pole piece due to the edge unevenness or the tiny protrusions caused by the cutting, stamping and other processes.

[0013] Preferably, the ceramic coating region extends along the edge of the substrate.

[0014] In a direction perpendicular to the extension direction of the ceramic coating region, the size of the ceramic coating region is equal to L, wherein 1 mm≤L≤20 mm.

[0015] According to a second aspect of the present application, a battery pole group is provided, comprising a positive pole piece and a negative pole piece, both of which are the battery pole piece according to any one of the above technical solutions, thus having all the beneficial technical effects of the battery pole piece, which will not be described here again.

[0016] Preferably, the positive pole piece and the negative pole piece are arranged in parallel, and the positive pole piece and the negative pole piece are alternately arranged along a first direction, wherein the first direction is perpendicular to the substrate of the positive pole piece.

[0017] In the first direction, the positive pole piece and the negative pole piece are projected onto a plane perpendicular to the first direction, wherein the projection of the material coating region of the negative pole piece covers the projection of the material coating region of the positive pole piece.

[0018] Preferably, for any side of the material coating region of the negative pole piece, in the extension direction of the any side, the size of the one end of the any side in the extension direction of the any side beyond the corresponding end of the material coating region of the positive pole piece is ΔS, wherein 1 mm≤ΔS≤4 mm.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] The battery electrode provided in this application, by setting a ceramic coating area at the edge of the substrate and fully coating the ceramic coating area with a ceramic coating part, can not only effectively cover the edge unevenness or small protrusions caused by cutting, stamping and other processes, thus preventing burrs on the electrode from piercing the separator; but also effectively prevent lithium ions from depositing in the edge area of ​​the electrode, thus avoiding the impact of lithium dendrites on battery performance.

[0021] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a front view of the positive electrode sheet provided in Embodiment 1 of this application;

[0024] Figure 2 This is a front view of the negative electrode sheet provided in Embodiment 1 of this application;

[0025] Figure 3 This is a front view schematic diagram of the battery electrode assembly provided in Embodiment 1 of this application;

[0026] Figure 4 for Figure 3 A magnified structural diagram of the provided battery electrode at point A;

[0027] Figure 5 This is a front view of the positive electrode sheet provided in Embodiment 2 of this application;

[0028] Figure 6 This is a front view of the negative electrode sheet provided in Embodiment 2 of this application;

[0029] Figure 7 This is a front view schematic diagram of the battery electrode assembly provided in Embodiment 2 of this application;

[0030] Figure 8 This is a front view of the positive electrode sheet provided in Embodiment 3 of this application;

[0031] Figure 9 This is a front view of the negative electrode sheet provided in Embodiment 3 of this application;

[0032] Figure 10A front view structural schematic diagram of a battery pole group provided in Embodiment Three of the present application.

[0033] Reference signs:

[0034] 10 - positive electrode tab; 11 - positive electrode ceramic coating area; 12 - positive electrode material coating area; 20 - negative electrode tab; 21 - negative electrode ceramic coating area; 22 - negative electrode material coating area; 31 - positive electrode ceramic coating layer part; 32 - negative electrode ceramic coating layer part; 41 - positive electrode active material part; 42 - negative electrode active material part; 5 - pole group fixing part; F2 - second direction; F3 - third direction. DETAILED DESCRIPTION

[0035] The technical solutions of the present application will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application.

[0036] The components of the embodiments of the present application generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application.

[0037] Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

[0038] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for description purposes and cannot be understood as indicating or implying relative importance.

[0039] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0040] The following will be described with reference to Figures 1 to 10The battery pole piece and the battery pole group according to some embodiments of the present application are described.

[0041] Referring to Figures 1 to 10 As shown in the drawings, the embodiments of the first aspect of the present application provide a battery pole piece, comprising a current collector, an active material part and a ceramic coating part, the current collector comprises a tab and a base connected to each other, the edge of the base is provided with a ceramic coating area, and the part of the base other than the ceramic coating area is a material coating area. Wherein, the active material part is coated on the material coating area, and the ceramic coating part is coated on the ceramic coating area.

[0042] According to the above technical features, the battery pole piece provided by the present application can effectively cover the uneven edges or small protrusions caused by cutting, stamping and other processes through the ceramic coating part, avoid the burrs on the pole piece from piercing the separator, and effectively hinder the deposition of lithium ions in the edge area of the pole piece, thereby avoiding the influence of lithium dendrites on the performance of the battery.

[0043] Preferably, as Figures 1 to 10 shown, the above-mentioned base can be rectangular to adapt to the shape of the square battery cell. However, it is not limited to this, and the shape of the above-mentioned base can be adaptively adjusted according to the shape of the battery cell, such as circular, oval, polygonal or other special shapes.

[0044] Preferably, as shown in the drawings, in the first direction, the size of the active material part and the size of the ceramic coating part are both equal to a predetermined thickness H. Wherein, the first direction can be perpendicular to the above-mentioned base, so that when the battery pole piece is stacked along the first direction, the uniformity of the force received by the current collector can be ensured.

[0045] Preferably, the range of the above-mentioned predetermined thickness can be 30μm~200μm, in other words, 30μm≤H≤200μm.

[0046] Preferably, as Figures 1 to 10 shown, the ceramic coating area can extend along the edge of the base where the ceramic coating area is located, and in a direction perpendicular to the extension direction of the ceramic coating area, the size of the ceramic coating area is equal to L, wherein 1mm≤L≤20mm.

[0047] In other words, as Figures 1 to 10 shown, taking the case where the ceramic coating area is provided on the first edge and the second edge as an example, the extension direction of the ceramic coating area located on the first edge and / or the second edge can be the third direction F3, and the above-mentioned L value can be understood as the size of the ceramic coating area provided on the first edge and / or the second edge in the second direction F2. As Figures 1 to 10As shown, the extending direction of the ceramic coating region located at the third edge and / or the fourth edge can be the second direction F2, and the L value can be understood as the dimension of the ceramic coating region located at the third edge and / or the fourth edge in the third direction F3.

[0048] Preferably, as shown, the tab can be connected with the first edge of the substrate, and at least part of the ceramic coating region can be arranged along the edge of the first edge to avoid unevenness or small protrusions on the edge of the first edge and deposition of lithium ions in the edge region of the first edge. Figures 1 to 10

[0049] Preferably, the second edge opposite to the first edge of the substrate is arranged, and at least another part of the ceramic coating region can be arranged along the edge of the second edge. As shown, the first edge and the second edge opposite to each other in the second direction F2 are shown in the figure. Figures 1 to 10

[0050] Preferably, the two edges adjacent to the first edge of the substrate are the third edge and the fourth edge, respectively, and at least another part of the ceramic coating region can be arranged along the edge of the third edge and the edge of the fourth edge, respectively. As shown, the third edge and the fourth edge opposite to each other in the third direction F3 are shown in the figure. Figures 1 to 10

[0051] As shown in Figure 1 , Figure 5 and Figure 8 , the example of the battery pole piece being a positive pole piece is shown in the figure, and correspondingly, the tab of the positive pole piece is a positive tab 10, the substrate of the positive pole piece is a positive substrate, the ceramic coating region of the positive pole piece is a positive ceramic coating region 11, and the material coating region of the positive pole piece is a positive material coating region 12. Correspondingly, the ceramic coating part of the positive pole piece is a positive ceramic coating part 31, and the active material part of the positive pole piece is a positive active material part 41.

[0052] As shown in Figure 2 , Figure 6 and Figure 9 , the example of the battery pole piece being a negative pole piece is shown in the figure, and correspondingly, the tab of the negative pole piece is a negative tab 20, the substrate of the negative pole piece is a negative substrate, the ceramic coating region of the negative pole piece is a negative ceramic coating region 21, and the material coating region of the negative pole piece is a negative material coating region 22. Correspondingly, the ceramic coating part of the negative pole piece is a negative ceramic coating part 32, and the active material part of the negative pole piece is a negative active material part 42.

[0053] According to the different positions of the ceramic coating region, as shown in Figures 1 to 10 , three different examples of the battery pole piece provided by the present application are shown, and specifically as follows:

[0054] ​​​Embodiment one, as shown in Figures 1 to 4 The ceramic coating area is arranged along the first edge and the second edge of the positive electrode substrate, respectively.

[0055] Correspondingly, as shown in Figure 1 The positive electrode ceramic coating area 11 is arranged along the edges of the first edge and the second edge of the positive electrode substrate, respectively.

[0056] Correspondingly, as shown in Figure 2 The negative electrode ceramic coating area 21 is arranged along the edges of the first edge and the second edge of the negative electrode substrate, respectively.

[0057] Embodiment two, as shown in Figures 5 to 7 The ceramic coating area is arranged along the four edges of the substrate, respectively, to ensure the uniformity of the stress around the electrode sheet.

[0058] Correspondingly, as shown in Figure 5 The positive electrode ceramic coating area 11 is arranged along the edges of the four edges of the positive electrode substrate, respectively.

[0059] Correspondingly, as shown in Figure 6 The negative electrode ceramic coating area 21 is arranged along the edges of the four edges of the negative electrode substrate, respectively.

[0060] Embodiment three, as shown in Figures 8 to 10 The ceramic coating area is arranged along the first edge, the third edge and the fourth edge of the substrate, respectively.

[0061] Correspondingly, as shown in Figure 1 The positive electrode ceramic coating area 11 is arranged along the edges of the first edge, the third edge and the fourth edge of the positive electrode substrate, respectively.

[0062] Correspondingly, as shown in Figure 2 The negative electrode ceramic coating area 21 is arranged along the edges of the first edge, the third edge and the fourth edge of the negative electrode substrate, respectively.

[0063] It should be noted that the materials of the positive electrode ceramic coating part 31, the positive electrode active material part 41, the negative electrode ceramic coating part 32 and the negative electrode active material part 42 are the existing technologies in the art, which will not be described here.

[0064] Embodiments of the second aspect of the application also provide a battery pole group comprising the battery pole sheet of any of the above embodiments, thus having all the beneficial technical effects of the battery pole sheet, which will not be described here.

[0065] Preferably, as shown in Figure 3 , Figure 7 and Figure 10As shown, the battery pole group can include the plurality of positive pole pieces and the plurality of negative pole pieces, both of the positive pole pieces and the negative pole pieces are arranged in parallel, and both of the positive pole pieces and the negative pole pieces are arranged alternately along the first direction to push and stack to form the electrode assembly.

[0066] Preferably, as shown in Figure 3 , Figure 7 and Figure 10 , the battery pole group can further include a pole group fixing part 5, the pole group fixing part 5 can extend along the first direction, and both ends of the pole group fixing part 5 can be attached to two end faces of the electrode assembly in the first direction to achieve the fixation of the electrode assembly.

[0067] Preferably, as shown in Figure 3 , Figure 7 and Figure 10 , the number of the pole group fixing part 5 can be multiple, and the multiple pole group fixing parts 5 can be arranged on both sides of the electrode assembly in the third direction F3 along the second direction F2 to improve the fixation stability of the electrode assembly.

[0068] Optionally, the pole group fixing part 5 can be an insulating tape.

[0069] Preferably, as shown in Figure 3 , Figure 7 and Figure 10 , in the first direction, the positive pole piece and the negative pole piece are projected onto a plane perpendicular to the first direction, wherein the projection of the material coating area of the negative pole piece covers the projection of the material coating area of the positive pole piece, so as to further reduce the lithium precipitation phenomenon at the edge of the positive pole piece.

[0070] Preferably, as shown in Figure 4 , for any side of the negative material coating area 22, in any side extension direction, the size of the one end of the side in its extension direction beyond the corresponding end of the positive material coating area 12 is ΔS, wherein 1mm≤ΔS≤4mm.

[0071] As shown in Figure 4 , for the side of the negative material coating area 22 corresponding to the second side, in the third direction F3, the size of the one end of the side of the negative material coating area 22 corresponding to the second side in the third direction F3 beyond the corresponding end of the positive material coating area 12 is the above ΔS.

[0072] As shown in Figure 4 , for the side of the negative material coating area 22 corresponding to the third side, in the second direction F2, the size of the one end of the side of the negative material coating area 22 corresponding to the third side in the second direction F2 beyond the corresponding end of the positive material coating area 12 is also the above ΔS.

[0073] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery pole piece, characterized by, The battery pole piece comprises a current collector, an active material part, and a ceramic coating part, the current collector comprises a tab and a base connected to each other, an edge of the base is provided with a ceramic coating area, and a part of the base other than the ceramic coating area is a material coating area; The active material part is coated on the material coating area, and the ceramic coating part is coated on the ceramic coating area.

2. The battery pole piece according to claim 1, wherein The base is rectangular, the tab is connected to a first edge of the base, and At least a part of the ceramic coating area is arranged along an edge of the first edge.

3. The battery pole piece of claim 2, wherein, A second edge of the base is arranged opposite to the first edge, and at least another part of the ceramic coating area is arranged along an edge of the second edge.

4. The battery pole piece according to claim 2 or 3, wherein Two edges of the base adjacent to the first edge are a third edge and a fourth edge, respectively, and at least another part of the ceramic coating area is arranged along an edge of the third edge and an edge of the fourth edge, respectively.

5. The battery pole piece of claim 1, wherein, In a direction perpendicular to the base, the size of the active material part and the size of the ceramic coating part are both equal to a predetermined thickness H.

6. The battery pole piece of claim 5, wherein, 30 μm ≤ H ≤ 200 μm.

7. The battery pole piece according to claim 1, wherein The ceramic coating area extends along an edge of the base, and In a direction perpendicular to the extension direction of the ceramic coating area, the size of the ceramic coating area is equal to L, wherein 1 mm ≤ L ≤ 20 mm.

8. A battery pole assembly, characterized by The positive pole piece and the negative pole piece are both the battery pole piece according to any one of claims 1 to 7.

9. The battery pole group according to claim 8, wherein The positive pole piece and the negative pole piece are arranged in parallel and alternately along a first direction, and the first direction is perpendicular to the base of the positive pole piece, and In the first direction, the positive pole piece and the negative pole piece are projected onto a plane perpendicular to the first direction, and the projection of the material coating area of the negative pole piece covers the projection of the material coating area of the positive pole piece.

10. The battery pole group according to claim 9, wherein For any edge of the material coating area of the negative pole piece, in the extension direction of the any edge, the size of the end of the any edge in the extension direction of the any edge beyond the corresponding end of the material coating area of the positive pole piece is ΔS, wherein 1 mm ≤ ΔS ≤ 4 mm.

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