Battery pole core and lithium ion battery

Abstract

The utility model discloses a battery pole core and lithium ion battery relates to battery pole core technical field. The battery pole core includes pole piece and diaphragm, and the active material layer surface of at least one side of pole piece is equipped with recess, and the surface of diaphragm is coated with reinforcing layer, and reinforcing layer can cover recess. The surface of diaphragm is coated with reinforcing layer, and reinforcing layer can cover the recess of pole piece surface, and compared with prior art, the pole piece of etching because of thermal expansion, sets up reinforcing layer, can reduce the probability of short circuit of battery caused by puncturing diaphragm.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, and in particular relates to a battery electrode core and a lithium-ion battery. Background Technology

[0002] With the rapid development of new energy vehicles and electronic communication equipment, consumers' demand for batteries that combine high capacity, long life, high stability, and high power density is increasing rapidly. In order to improve the energy density of lithium-ion batteries, battery electrodes often have a large compaction density and thickness. This not only increases the energy density of the battery, but also increases the resistance to lithium-ion transport in the active material, and increases the difficulty of electrolyte wetting.

[0003] Based on this, laser etching technology is currently used to create a large number of regular etching grooves on the surface of the active material layer of the electrode, which helps lithium ions diffuse rapidly in the electrode, reduces polarization under high current conditions, and significantly improves the fast charging performance of the battery. However, due to thermal expansion, the etched electrode has low compaction at the etched position and an uneven morphology, which can easily puncture the separator and cause a short circuit in the battery. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a battery core and a lithium-ion battery, addressing the issue that the expansion of existing etched electrode sheets easily punctures the separator.

[0005] To address the aforementioned issues, this utility model provides a battery core comprising an electrode sheet and a separator. The surface of the active material layer on at least one side of the electrode sheet is provided with a groove, and the surface of the separator is coated with a reinforcing layer that covers the groove.

[0006] As a further improvement to the above technical solution: Preferably, the depth of the groove is d, the width of the groove is w, and d / w≤0.36.

[0007] Preferably, 0.1μm≤d≤0.5μm; 0.25μm≤w≤5μm.

[0008] Preferably, the surface of the active material layer on at least one side of the electrode is provided with a plurality of grooves at intervals, the distance between two adjacent grooves is L, the width of the reinforcing layer is l, and L≥l.

[0009] Preferably, 10μm≤L≤100μm.

[0010] Preferably, the width of the reinforcing layer is l, the width of the groove is w, and l ≥ w.

[0011] Preferably, the thickness of the reinforcing layer is h, where h ≥ 0.5 μm.

[0012] Preferably, the groove is an arc-shaped groove, and the edges of the groove are rounded.

[0013] Preferably, the projection distance from the outer edge of the rounded corner to the bottom of the groove on the plane where the opening of the groove is located is H, where 0.2μm≤H≤5μm.

[0014] Preferably, the groove is an etching groove.

[0015] On the other hand, this utility model embodiment provides a lithium-ion battery, which includes a battery casing and the aforementioned battery electrode core, wherein the battery electrode core is installed inside the battery casing.

[0016] The battery electrode core and lithium-ion battery provided in this embodiment of the present invention have at least the following beneficial effects compared with the prior art: the battery electrode core has a reinforcing layer coated on the surface of the separator. The reinforcing layer can cover the groove on the surface of the active material layer on one side of the electrode. Compared with the existing technical solutions, the reinforcing layer can reduce the probability of the battery short circuit caused by puncturing the separator when the etched electrode expands due to heat. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a lithium-ion battery provided in one embodiment of the present invention.

[0019] The reference numerals in the accompanying drawings are as follows: 100. Battery core; 110. Electrode sheet; 111. Groove; 112. Rounded corner; 120. Separator; 121. Reinforcing layer. Detailed Implementation

[0020] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0021] In the description of this utility model, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] like Figure 1 As shown, an embodiment of the present invention provides a battery core 100. The lithium-ion battery 100 includes an electrode 110 and a separator 120. The surface of the active material layer on at least one side of the electrode 110 is provided with a groove 111. The surface of the separator 120 is coated with a reinforcing layer 121, which can cover the groove 111.

[0024] The battery core 100 has a reinforcing layer 121 coated on the surface of the separator 120. The reinforcing layer 121 can cover the groove 111 on the surface of the active material layer on one side of the electrode 110. Compared with the existing technology, the reinforcing layer 121 can reduce the probability of the separator being punctured and causing a short circuit in the battery due to the thermal expansion of the etched electrode 110.

[0025] Specifically, the reinforcing layer 121 is formed by thickening a local coating of the diaphragm 120.

[0026] Specifically, the electrode 110 is a positive electrode or a negative electrode, that is, the positive electrode or negative electrode of the battery core 100 can be an electrode with the aforementioned groove 111.

[0027] In this embodiment, grooves 111 are provided on the surface of the active material layer on both sides of the electrode 110, and reinforcing layers 121 are provided on the diaphragms 120 stacked on both sides of the electrode 110.

[0028] In this embodiment, as Figure 1As shown, the thickness of the reinforcing layer 121 is h, where h ≥ 0.5 μm. The depth of the groove 111 is d, and the width of the groove 111 is w, with d / w ≤ 0.36. Reducing the depth of the groove 111 lowers the risk of short circuit in the battery core 100. 0.1 μm ≤ d ≤ 0.5 μm; 0.25 μm ≤ w ≤ 5 μm.

[0029] The battery electrode 100 provided in this embodiment of the utility model, such as Figure 1 As shown, the surface of the active material layer on at least one side of the electrode 110 is provided with a plurality of grooves 111 spaced apart, the distance between two adjacent grooves 111 is L, the width of the reinforcing layer 121 is l, and L≥l. In this embodiment, 10μm≤L≤100μm. The width of the reinforcing layer 121 is l, the width of the grooves 111 is w, and l≥w, ensuring that the reinforcing layer 121 can cover the opening of the grooves 111.

[0030] The battery electrode 100 provided in this embodiment of the utility model, such as Figure 1 As shown, the groove 111 is an arc-shaped groove, and the edge of the groove 111 is provided with a rounded corner 112. Since the edge of the groove 111 is the greatest risk of puncturing the separator and causing a short circuit in the battery, the rounded corner 112 is provided on the edge of the groove 111 to make the edge of the groove 111 smooth, which can reduce the probability of the edge of the groove 111 puncturing the separator and causing a short circuit in the battery.

[0031] The groove 111 is an etching groove. After the groove 111 is etched on the surface of the electrode 110, the groove 111 is rolled to form a rounded corner 112 at the edge of the groove 111. The etched groove 111 has a smoother appearance and no sharp corners, which reduces the risk of puncturing the separator and causing a short circuit in the battery.

[0032] The heat generated by laser etching causes the active material to expand and fall off, resulting in lower compaction at the etched position (groove 111). During the cyclic expansion process, the active material will fall off, and after etching, the active material will have an irregular sharp angle shape, which can easily puncture the diaphragm. After rolling, the etched position (groove 111) has no obvious sharp angle, and the risk of puncturing the diaphragm is lower.

[0033] In this embodiment, as Figure 1 As shown, the projection distance from the outer edge of the fillet 112 to the bottom of the groove 111 on the plane where the opening of the groove 111 is located is H, 0.2μm≤H≤5μm, which limits the opening angle of the groove 111 after rolling.

[0034] In addition, such as Figure 1As shown, another embodiment of this utility model provides a lithium-ion battery, which includes a battery casing and a battery electrode 100 as provided in any of the above embodiments. The battery electrode 100 is installed inside the battery casing. The specific structure of the battery electrode 100 is the same as described in the above embodiments. Since this lithium-ion battery adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0035] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be included within the protection scope of this utility model.

Claims

1. A battery electrode core, characterized in that, The device includes an electrode and a separator. The surface of the active material layer on at least one side of the electrode is provided with a groove, and the surface of the separator is coated with a reinforcing layer that can cover the groove.

2. The battery electrode core according to claim 1, characterized in that, The groove has a depth of d and a width of w, and d / w ≤ 0.

36.

3. The battery electrode core according to claim 2, characterized in that, 0.1μm≤d≤0.5μm; 0.25μm≤w≤5μm.

4. The battery electrode core according to claim 1, characterized in that, The surface of the active material layer on at least one side of the electrode is provided with a plurality of grooves spaced apart, the distance between two adjacent grooves is L, the width of the reinforcing layer is l, and L≥l.

5. The battery electrode core according to claim 4, characterized in that, 10μm≤L≤100μm.

6. The battery electrode core according to claim 1, characterized in that, The width of the reinforcing layer is l, the width of the groove is w, and l ≥ w.

7. The battery electrode core according to claim 1, characterized in that, The thickness of the reinforcing layer is h, where h ≥ 0.5 μm.

8. The battery electrode core according to claim 1, characterized in that, The groove is an arc-shaped groove, and the edges of the groove are rounded.

9. The battery electrode core according to claim 8, characterized in that, The distance H from the outer edge of the rounded corner to the bottom of the groove on the plane where the opening of the groove is located is 0.2μm≤H≤5μm.

10. A lithium-ion battery, characterized in that, It includes a battery casing and a battery core as described in any one of claims 1 to 9, wherein the battery core is installed inside the battery casing.

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