Lithium ion battery electrode plate and lithium ion battery

Abstract

The utility model discloses a lithium ion battery electrode plate, which comprises a current collector and a protective layer entirety, the surface of the current collector is coated with an active layer, and the active layer comprises an active material layer and a protective layer from inside to outside; a plurality of grooves are formed in the surface of the active layer at equal intervals in the length direction, reinforcing rib positions are formed on the active layer between every two grooves, and the upper end faces of the reinforcing rib positions are sunken inwards to form current collecting holes. According to the utility model, the anti-falling surface formed by the bulges is designed on the surface of the current collector, so that after the active layer is coated on the surface of the current collector, the bonding force between the active layer and the current collector can be improved, and the stripping phenomenon is not easy to occur; the grooves are formed in the surface of the active layer at equal intervals, the contact area with electrolyte can be increased through the formed grooves and the reinforcing rib positions, so that the overall infiltration rate can be improved, in addition, the reinforcing rib positions can also serve as auxiliary reinforcing parts, and the overall strength is higher.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium ion batteries, in particular to a lithium ion battery electrode sheet and a lithium ion battery. Background Art

[0002] Lithium-ion batteries have attracted widespread attention due to their high energy density and good cycle performance. Lithium-ion batteries are mainly composed of (positive and negative) electrodes, separators and electrolytes. The electrodes are composed of current collectors and active layers coated on the surface of the current collectors.

[0003] At present, during the production process of electrodes, the electrode parts need to be compacted first (in order to ensure the volume energy density and mass energy density of the battery) to ensure the overall battery performance. However, after compaction, the electrolyte infiltration rate and uniformity of the electrode will become poor, resulting in the battery rate performance and cycle performance being affected.

[0004] In view of this, a lithium ion battery electrode sheet and a lithium ion battery are proposed. Utility Model Content

[0005] The purpose of the utility model is to provide a lithium ion battery electrode sheet and a lithium ion battery in order to solve the above-mentioned problems.

[0006] The technical solution adopted by the utility model is as follows:

[0007] In a first aspect of the utility model, a lithium-ion battery electrode sheet comprises: a current collector and a protective layer as a whole, wherein the surface of the current collector is coated with an active layer, wherein the active layer comprises an active material layer and a protective layer from inside to outside;

[0008] The surface of the active layer is provided with a plurality of grooves at equal intervals along the length direction, and reinforcing ribs are formed on the active layer between the grooves, and the upper end surfaces of the reinforcing ribs are recessed inwards to form collecting holes.

[0009] In a preferred embodiment, the bottom end surface of the collecting hole and the bottom end surface of the groove are on the same horizontal plane, and the groove and the reinforcing rib are both trapezoidal.

[0010] In a preferred embodiment, the outer end surface of the current collector is protruding to form a protrusion, and the protrusion is multiple and evenly arranged on the surface of the current collector.

[0011] In a preferred embodiment, the protective layer as a whole includes an adhesive layer and an isolation layer from the inside to the outside.

[0012] In a preferred embodiment, the adhesive layer is entirely made of acrylic resin glue, and the thickness of the adhesive layer is 0.5-2 μm.

[0013] In a preferred embodiment, the isolation layer is a PP film or a PE film, and the thickness of the isolation layer is 1.5-2 μm.

[0014] In a second aspect of the present invention, a lithium ion battery comprises the lithium ion battery electrode sheet as described above.

[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:

[0016] 1. In the present invention, grooves are designed at equal intervals on the surface of the active layer. The formed grooves and reinforcing ribs can increase the contact area with the electrolyte, thereby improving the overall infiltration rate. In addition, the reinforcing ribs can also serve as auxiliary reinforcement parts, and the overall strength is higher;

[0017] 2. In the present invention, an anti-stripping surface formed by protrusions is designed on the surface of the current collector. After the active layer is coated on the surface of the current collector, the adhesion between the active layer and the current collector itself can be improved, and the peeling phenomenon is not easy to occur;

[0018] 3. In the utility model, an isolation layer is designed on the surface of the active material layer. Since the PP film or PE film has micropores that allow the electrolyte to pass through, it will not affect the normal infiltration operation. When the battery overheats, the PP film or PE film has a high-temperature self-closing function, that is, it closes the micropores, which can isolate current conduction and prevent explosion, making it safer to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the layered structure of the utility model as a whole;

[0020] Figure 2 It is a structural cross-sectional view of the active layer in the utility model;

[0021] Figure 3 It is a schematic diagram of the layered structure of the protective layer in the utility model.

[0022] Markings in the figure: 1-active layer, 10-reinforcement rib position, 11-current collecting hole, 12-groove, 101-protective layer, 1011-adhesive layer, 1012-isolation layer, 102-active material layer, 2-current collector, 201-protrusion. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0024] Reference Figure 1-3A lithium-ion battery electrode sheet includes a current collector 2 and a protective layer as a whole. The surface of the current collector 2 is coated with an active layer 1. The active layer 1 includes an active material layer 102 and a protective layer 101 from the inside to the outside. The surface of the active layer 1 is provided with a plurality of grooves 12 at equal intervals along the length direction. Reinforcement ribs 10 are formed on the active layer 1 between the grooves 12. Grooves 12 are designed at equal intervals on the surface of the active layer 1. The formed grooves 12 and reinforcement ribs 10 can increase the subsequent contact area with the electrolyte, thereby improving the overall infiltration rate. In addition, the reinforcement ribs 10 can also be used as auxiliary reinforcement parts, and the overall strength is higher.

[0025] The current collector 2 can be made of materials corresponding to the positive and negative electrodes, which will not be elaborated here.

[0026] Furthermore, the upper end surface of the reinforcing rib position 10 is recessed inward to form a collecting hole 11, and the bottom end surface of the collecting hole 11 and the bottom end surface of the groove 12 are on the same horizontal plane. The groove 12 and the reinforcing rib position 10 are both trapezoidal. The collecting hole 11 can ensure the uniformity of the active layer 1 when it is infiltrated with the electrolyte as much as possible.

[0027] Furthermore, the outer end surface of the current collector 2 protrudes to form a protrusion 201, and there are multiple protrusions 201 that are evenly arranged on the surface of the current collector 2. An anti-stripping surface formed by the protrusions 201 is designed on the surface of the current collector 2. After the active layer 1 is coated on the surface of the current collector 2, the adhesion between the active layer 1 and the current collector 2 itself can be improved, and peeling is not easy to occur.

[0028] The protrusion 201 is preferably in a semicircular shape, but is not limited to the above shape.

[0029] Furthermore, the protective layer 101 as a whole includes an adhesive layer 1011 and an isolation layer 1012 from the inside to the outside. The adhesive layer 1011 as a whole is an acrylic resin glue. The thickness of the adhesive layer 1011 is 0.5~2μm. Acrylic resin has good adhesion and toughness, thereby ensuring the adhesion effect of the protective layer 101, and can be wound with the pole piece itself.

[0030] Furthermore, the isolation layer 1012 is a PP film or a PE film, and the thickness of the isolation layer 1012 is 1.5~2μm. Since the PP film or the PE film has micropores for the electrolyte to pass through, it will not affect the normal infiltration operation. When the battery overheats, the PP film or the PE film has a high-temperature self-closing function, that is, it closes the micropores, which can isolate the current conduction to prevent explosion, and is safer when used.

[0031] The embodiment of the utility model also provides a lithium-ion battery, including a lithium-ion battery electrode sheet as described above. Since the lithium-ion battery has the battery electrode sheet mentioned above, the lithium battery can be safer when used, while ensuring the use effect of the battery itself.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A lithium-ion battery electrode sheet, comprising a current collector and a protective layer as a whole, characterized in that: The surface of the current collector is coated with an active layer, and the active layer includes an active material layer and a protective layer from inside to outside; The surface of the active layer is provided with a plurality of grooves at equal intervals along the length direction, and reinforcing ribs are formed on the active layer between the grooves, and the upper end surfaces of the reinforcing ribs are recessed inwards to form collecting holes.

2. A lithium-ion battery electrode sheet as claimed in claim 1, characterized in that: The bottom end surface of the collecting hole and the bottom end surface of the groove are on the same horizontal plane, and the groove and the reinforcing rib are both trapezoidal.

3. A lithium-ion battery electrode sheet as claimed in claim 1, characterized in that: The outer end surface of the current collector protrudes to form a protrusion, and the protrusion is multiple and evenly arranged on the surface of the current collector.

4. A lithium-ion battery electrode sheet as claimed in claim 1, characterized in that: The protective layer as a whole comprises an adhesive layer and an isolation layer from the inside to the outside.

5. A lithium-ion battery electrode sheet as claimed in claim 4, characterized in that: The adhesive layer is entirely made of acrylic resin glue, and the thickness of the adhesive layer is 0.5-2 μm.

6. A lithium-ion battery electrode sheet as claimed in claim 4, characterized in that: The isolation layer is a PP film or a PE film, and the thickness of the isolation layer is 1.5-2 μm.

7. A lithium ion battery, characterized in that: It comprises a lithium-ion battery electrode sheet as claimed in any one of claims 1 to 6.

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