Lithium battery cell and lithium ion battery

Abstract

The utility model relates to the technical field of lithium ion batteries, and provides a lithium battery cell and a lithium ion battery, which comprise a cathode current collector, a cathode tab, a cathode active material layer, an anode current collector, an anode tab and an anode active material layer, the cathode active material layer is used for storing or releasing lithium ions; the cathode active material layer is coated on the cathode current collector; the cathode active material layer is provided with a first area, the inner side of the first area is provided with a hollow second area, and the cathode tab is arranged on the cathode current collector in the second area; the anode tab is arranged on the anode current collector; the anode active material layer is used for storing or releasing lithium ions; the anode active material layer is coated on the anode current collector; and a first groove is formed in the first region on the outer side of the second region.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium ion batteries, and more specifically, relates to a lithium battery core and a lithium ion battery. Background Art

[0002] Soft-packaged lithium-ion batteries are widely used in various digital products and mobile devices due to their high energy density, low self-discharge, wide operating temperature range, and environmental friendliness. With the increasing popularity of portable mobile communication tools and smart wearable devices, as well as the continuous evolution of electronic products, the performance requirements for batteries are becoming increasingly demanding. Polymer lithium-ion batteries, the most commonly used power source for electronic products, place even more stringent demands on energy density and charging speed.

[0003] Due to the structural design of the tab position, the current density of lithium-ion batteries is unevenly distributed during the charge and discharge process, and the current density is highest near the positive and negative tabs of the battery. At present, the anode tab corresponds to the cathode sheet position and the anode corresponds to the cathode tab position. Green glue or yellow glue is generally used to directly cover the positive electrode active material to prevent excessive lithium ions from escaping to the anode and prevent lithium precipitation (lithium precipitation: precipitation of metallic lithium). However, in long cycles, especially during high-rate charging, the current density is highest at the positive and negative tab positions, and the lithium ion extraction rate of the cathode at this position is fast. When the lithium insertion rate of the anode cannot keep up with the lithium ion inflow rate, lithium precipitation is likely to occur. In severe cases, the precipitated lithium dendrites will pierce the diaphragm, causing short circuit failure and posing a safety hazard.

[0004] Regarding the working principle of lithium-ion batteries and the flow of lithium ions during charging and discharging, please refer to (Chinese invention patent; publication number: CN112750976A; subject name: lithium battery cell and lithium-ion battery; applicant: Zhuhai Guanyu Battery Co., Ltd.; publication date: 2021.05.04). Lithium battery cells generally include: positive electrode sheets and negative electrode sheets; the negative electrode sheet includes: a negative current collector and a negative electrode active material layer coated on the negative current collector; the positive electrode sheet includes: a positive current collector and a positive electrode active material layer coated on the positive current collector; during the charging and discharging process of the positive and negative electrode sheets, lithium ions can be transferred between the negative electrode active material layer and the positive electrode active material layer. Utility Model Content

[0005] The purpose of the utility model is to provide a lithium battery cell to solve the technical problem in the prior art that lithium ions are released from the cathode at a fast speed, and lithium deposition is likely to occur when the lithium insertion speed of the anode cannot keep up with the lithium ion inflow speed.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is to provide a lithium battery cell, a lithium battery cell comprising:

[0007] cathode current collector;

[0008] cathode tab;

[0009] A cathode active material layer; the cathode active material layer is used to store or release lithium ions; the cathode active material layer is coated on the cathode current collector; the cathode active material layer has a first region, the inside of the first region has a hollowed-out second region, and the cathode tab is disposed on the cathode current collector within the second region;

[0010] anode current collector;

[0011] Anode tab; the anode tab is arranged on the anode current collector;

[0012] Anode active material layer; the anode active material layer is used to store or release lithium ions; the anode active material layer is coated on the anode current collector;

[0013] Wherein, a first groove is provided on the first area outside the second area.

[0014] Furthermore, the first groove is a laser-etched groove formed by laser etching.

[0015] Furthermore, there are multiple first grooves, and the multiple first grooves are arranged in parallel and at intervals.

[0016] Further, assuming that the depth of the first groove is h, the thickness of the cathode current collector is T, A=30% to 60%; wherein h=T*A; and / or

[0017] The width of the first groove is 30 to 200 μm; the distance between any two first grooves is 1 to 3 mm.

[0018] Furthermore, the width of the first region is set to W1, the length of the first region is set to L1, the width of the lithium battery cell is set to W3, the width of the cathode current collector is set to W4, the width of the second region is set to W5, and the length of the second region is set to L5;

[0019] Among them, (W5+6mm)≤W1≤W3; (L5+3mm)≤L1≤W4.

[0020] Furthermore, it also includes: a cathode protection glue layer; the cathode active material layer has a third area, the third area is etched with multiple second grooves, and the multiple second grooves are arranged in parallel and spaced apart; one side of the cathode protection glue layer is attached to the third area, and the other side of the cathode protection glue layer covers the outside of the cathode ear.

[0021] Furthermore, the width of the third region is set to W2, the length of the second region is set to L2, the width of the lithium battery cell is set to W3, the width of the cathode current collector is set to W4, the width of the cathode protection glue layer is set to W6, and the length of the cathode protection glue layer is set to L6;

[0022] Among them, (W6+6mm)≤W2≤W3; (L6+3mm)≤L2≤W4.

[0023] Furthermore, it also includes: an anode protection glue layer; the cathode active material layer has a fourth area, the fourth area is etched with a plurality of third grooves, and the plurality of third grooves are arranged in parallel and spaced apart; one side of the anode protection glue layer is attached to the fourth area, and the other side of the anode protection glue layer covers the outside of the anode ear.

[0024] Furthermore, the anode current collector is copper foil; and the cathode current collector is aluminum foil.

[0025] The present invention also provides a lithium-ion battery, comprising: the lithium battery cell, an electrolyte, and an insulating layer for insulation and allowing lithium ions to pass through; the electrolyte is filled between the cathode current collector and the anode current collector, and the insulating layer is arranged between the cathode current collector and the anode current collector.

[0026] The beneficial effects of the lithium battery cell provided by the present invention are as follows: compared with the prior art, the lithium battery cell provided by the present invention has a cathode tab electrically connected to a cathode current collector, a cathode active material layer is provided on the cathode current collector, and the cathode active material layer can store or release lithium ions; an anode tab electrically connected to an anode current collector, a anode active material layer is provided on the anode current collector, and the anode active material layer can store or release lithium ions; the cathode tab and the anode tab can be connected to an external circuit, and when the cathode tab and the anode tab are charged and discharged, lithium ions are transferred between the anode active material layer and the cathode active material layer; the cathode active material layer The cathode active material layer is covered on the cathode current collector, the cathode active material layer has a first area, the inside of the first area has a hollow second area, and the cathode tab is arranged on the cathode current collector in the second area, that is, the cathode tab is connected to the cathode current collector through the hollow second area; since the first area outside the second area has a first groove, when the current on the cathode tab contacts the cathode active material layer on the first area, the first groove reduces the cathode active material layer, slowing down the release of lithium ions from the cathode active material layer in the first area, thereby avoiding the situation where lithium precipitation is caused by the excessive release of lithium ions and the slow insertion of lithium ions in the anode active material layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1A schematic front view of a first groove formed on a cathode active material layer according to an embodiment of the present invention;

[0028] Figure 2 for Figure 1 An enlarged schematic diagram of the first and third regions;

[0029] Figure 3 A schematic diagram of the arrangement of the cathode protection adhesive layer provided in an embodiment of the present utility model;

[0030] Figure 4 A schematic diagram of the arrangement of the anode protective adhesive layer provided in an embodiment of the present utility model;

[0031] Figure 5 This is a schematic diagram of the lithium-ion battery provided in an embodiment of the present utility model.

[0032] Among them, the reference numerals in the figures are:

[0033] 11-cathode current collector; 12-cathode tab; 13-cathode active material layer; 131-first region; 1311-first groove; 132-second region; 133-third region; 1331-second groove; 134-fourth region; 1341-third groove; 21-anode current collector; 22-anode tab; 23-anode active material layer; 31-cathode protection adhesive layer; 32-anode protection adhesive layer; 4-insulating layer. DETAILED DESCRIPTION

[0034] It should be noted that the specific embodiments are only used to explain the present invention and are not used to limit the present invention.

[0035] It should be noted that, in the description of the embodiments of this application, unless otherwise specified, " / " represents the meaning of "or". For example, A / B can represent A or B. "And / or" in this article is only a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0036] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” or “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element. When an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element.

[0037] It should be noted that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0038] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of such features.

[0039] It should be noted that the term "plurality" means two or more, unless otherwise clearly defined.

[0040] Please also refer to Figures 1 to 2 The lithium battery cell provided by the present invention is now described. The lithium battery cell includes: a cathode current collector 11, a cathode tab 12, a cathode active material layer 13, an anode current collector 21, an anode tab 22, and an anode active material layer 23; the cathode active material layer 13 is used to store or release lithium ions; the cathode active material layer 13 is coated on the cathode current collector 11; the cathode active material layer 13 has a first region 131, and a hollow second region 132 is provided inside the first region 131; the cathode tab 12 is provided on the cathode current collector 11 within the second region 132; the anode tab 22 is provided on the anode current collector 21; the anode active material layer 23 is used to store or release lithium ions; the anode active material layer 23 is coated on the anode current collector 21; wherein, the first region 131 outside the second region 132 has a first groove 1311.

[0041] In this way, the cathode tab 12 is electrically connected to the cathode current collector 11, and the cathode current collector 11 has a cathode active material layer 13, and the cathode active material layer 13 can store or release lithium ions; the anode tab 22 is electrically connected to the anode current collector 21, and the anode current collector 21 has an anode active material layer 23, and the anode active material layer 23 can store or release lithium ions; the cathode tab 12 and the anode tab 22 can be connected to an external circuit, and when the cathode tab 12 and the anode tab 22 are charged and discharged, lithium ions are transferred between the anode active material layer 23 and the cathode active material layer 13; the cathode active material layer 13 covers the cathode current collector 11, and the cathode active material layer 13 has a first region 131 The first region 131 has a hollow second region 132 on the inside, and the cathode tab 12 is arranged on the cathode current collector 11 in the second region 132, that is, the cathode tab 12 passes through the hollow second region 132 and is connected to the cathode current collector 11; since the first region 131 outside the second region 132 has a first groove 1311, when the current on the cathode tab 12 contacts the cathode active material layer 13 on the first region 131, the first groove 1311 reduces the cathode active material layer 13, slowing down the release of lithium ions from the cathode active material layer 13 on the first region 131, thereby avoiding the situation where lithium precipitation is caused by the excessive release of lithium ions and the slow insertion of lithium ions in the anode active material layer 23.

[0042] In one embodiment, the anode current collector 21 is copper foil. In one embodiment, the anode active material layer 23 is graphite.

[0043] In one embodiment, the cathode current collector 11 is aluminum foil. In one embodiment, the cathode active material layer 13 is any one of lithium cobalt oxide, lithium iron phosphate, and nickel-cobalt-manganese ternary material.

[0044] In one embodiment, the first region 131 is rectangular.

[0045] In one embodiment, the second region 132 is rectangular.

[0046] In one embodiment, the first groove 1311 is an etched groove.

[0047] Further, see Figures 1 to 2 As a specific embodiment of the lithium battery cell provided by the present invention, the first groove 1311 is a laser-etched groove formed by laser etching. In this way, the laser processing method is more efficient.

[0048] Further, see Figures 1 to 2 As a specific embodiment of the lithium battery cell provided by the present invention, there are multiple first grooves 1311, and the multiple first grooves 1311 are arranged in parallel and at intervals.

[0049] Further, see Figures 1 to 2 As a specific embodiment of the lithium battery cell provided by the present invention, assuming the depth of the first groove 1311 is h, the thickness of the cathode current collector 11 is T, and A = 30% to 60%; where h = T * A. In this way, the first groove 1311 reduces the thickness of the cathode current collector 11 while preventing the mechanical strength of the cathode active material layer 13 having the first groove 1311 from being too low.

[0050] In one embodiment, the width of the first groove 1311 is 30-200 μm; and the distance between any two first grooves 1311 is 1-3 mm.

[0051] Further, see Figures 1 to 2 As a specific embodiment of the lithium battery cell provided by the present invention, the width of the first region 131 is set to W1, the length of the first region 131 is set to L1, the width of the lithium battery cell is set to W3, the width of the cathode current collector 11 is set to W4, the width of the second region 132 is set to W5, and the length of the second region 132 is set to L5. Wherein, (W5 + 6mm) ≤ W1 ≤ W3; (L5 + 3mm) ≤ L1 ≤ W4. In this way, the area of ​​the first region 131 is large enough to divert the current transmitted by the cathode tab 12.

[0052] Further, see Figures 1 to 4 As a specific embodiment of the lithium battery cell provided by the present invention, it also includes: a cathode protection adhesive layer 31; a third region 133 is provided on the cathode active material layer 13, and a plurality of second grooves 1331 are etched on the third region 133, and the plurality of second grooves 1331 are arranged in parallel and spaced apart; one side of the cathode protection adhesive layer 31 is attached to the third region 133, and the other side of the cathode protection adhesive layer 31 covers the outside of the cathode tab 12. In this way, the cathode protection adhesive layer 31 can protect the outside of the cathode tab 12, and even if current is transmitted to the third region 133 where the cathode protection adhesive layer 31 is located, due to the plurality of second grooves 1331 etched on the third region 133, the current transmitted to the third region 133 is reduced, which reduces the release rate of lithium ions.

[0053] In one embodiment, the cathode protection glue layer 31 is green glue.

[0054] In one embodiment, the third region 133 is rectangular.

[0055] In one embodiment, the cathode current collector 11 is in a rectangular shape.

[0056] In one embodiment, the lithium battery cell roll is cylindrical.

[0057] Further, see Figures 1 to 4As a specific embodiment of the lithium battery cell provided by the present invention, the width of the third region 133 is set to W2, the length of the second region is set to L2, the width of the lithium battery cell is set to W3, the width of the cathode current collector 11 is set to W4, the width of the cathode protection adhesive layer 31 is set to W6, and the length of the cathode protection adhesive layer 31 is set to L6. Wherein, (W6 + 6mm) ≤ W2 ≤ W3; (L6 + 3mm) ≤ L2 ≤ W4. This way, the second region 132 has a large enough area for the cathode protection adhesive layer 31 to be placed and distribute the current.

[0058] Further, see Figures 1 to 4 As a specific embodiment of the lithium battery cell provided by the present invention, it also includes: an anode protective adhesive layer 32; a cathode active material layer 13 having a fourth region 134, with a plurality of third grooves 1341 etched in the fourth region 134, and the plurality of third grooves 1341 are arranged in parallel and spaced apart; one side of the anode protective adhesive layer 32 is attached to the fourth region 134, and the other side of the anode protective adhesive layer 32 covers the outside of the anode tab 22. In this way, when current from the anode tab 22 passes through the anode protective adhesive layer 32 and reaches the fourth region 134, the third grooves 1341 in the fourth region 134 can reduce the current.

[0059] In one embodiment, the anode protection glue layer 32 is green glue.

[0060] Further, see Figures 1 to 4 As a specific embodiment of the lithium battery cell provided by the present invention, the anode current collector 21 is copper foil; the cathode current collector 11 is aluminum foil.

[0061] See also Figures 1 to 5The present invention also provides a lithium-ion battery, comprising: a lithium battery cell, an electrolyte, and an insulating layer 4 for insulation and allowing lithium ions to pass through; the electrolyte is filled between the cathode current collector 11 and the anode current collector 21, and the insulating layer 4 is arranged between the cathode current collector 11 and the anode current collector 21. In this way, when the anode tab 22 and the cathode tab 12 discharge to the outside, the lithium ions in the anode active material layer 23 enter the electrolyte and pass through the insulating layer 4 to enter the cathode current collector 11; when the anode tab 22 and the cathode tab 12 are charged, the lithium ions in the cathode active material layer 13 enter the electrolyte and pass through the insulating layer 4 to enter the anode current collector 21; due to the use of the above-mentioned lithium battery cell, the cathode tab 12 is electrically connected to the cathode current collector 11, and the cathode current collector 11 has a cathode active material layer 13, and the cathode active material layer 13 can store or release lithium ions; the anode tab 22 is electrically connected to the anode current collector 21, and the anode current collector 21 has an anode active material layer 23, and the anode active material layer 23 can store or release lithium ions; the cathode tab 12 and the anode tab 22 can be connected to the external circuit. When charging and discharging are carried out between the cathode tab 12 and the anode tab 22, the lithium ions in the anode active material layer 13 enter the electrolyte and pass through the insulating layer 4 to enter the anode current collector 21. The cathode active material layer 23 and the cathode active material layer 13 are transferred to each other; the cathode active material layer 13 is covered on the cathode current collector 11, and the cathode active material layer 13 has a first area 131, and a hollow second area 132 is provided inside the first area 131. The cathode tab 12 is arranged on the cathode current collector 11 in the second area 132, that is, the cathode tab 12 is connected to the cathode current collector 11 through the hollow second area 132; since the first area 131 outside the second area 132 has a first groove 1311, when the current on the cathode tab 12 contacts the cathode active material layer 13 on the first area 131, the first groove 1311 reduces the cathode active material layer 13, slowing down the rate of release of lithium ions by the cathode active material layer 13 on the first area 131, thereby avoiding the situation where lithium deposition is caused by the excessive release of lithium ions and the slow insertion of lithium ions by the anode active material layer 23.

[0062] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and replacements can be made without departing from the technical principles of the present invention. These improvements and replacements should also be regarded as the scope of protection of the present invention.

Claims

1. A lithium battery cell, characterized in that: include: cathode current collector; cathode tab; Cathode active material layer; the cathode active material layer is used to store or release lithium ions; The cathode active material layer is coated on the cathode current collector; The cathode active material layer has a first region, the inside of the first region has a hollow second region, and the cathode tab is arranged on the cathode current collector in the second region; anode current collector; Anode tab; the anode tab is arranged on the anode current collector; Anode active material layer; the anode active material layer is used to store or release lithium ions; the anode active material layer is coated on the anode current collector; Wherein, a first groove is provided on the first area outside the second area.

2. The lithium battery cell according to claim 1, wherein: The first groove is a laser-etched groove formed by laser etching.

3. The lithium battery cell according to claim 1, wherein: There are multiple first grooves, and the multiple first grooves are arranged in parallel and at intervals.

4. The lithium battery cell according to claim 3, wherein: Assuming that the depth of the first groove is h, the thickness of the cathode current collector is T, A=30% to 60%; wherein h=T*A; and / or The width of the first groove is 30 to 200 μm; the distance between any two first grooves is 1 to 3 mm.

5. The lithium battery cell according to claim 1, wherein: Set the width of the first region to W1, the length of the first region to L1, the width of the lithium battery cell to W3, the width of the cathode current collector to W4, the width of the second region to W5, and the length of the second region to L5; Among them, (W5+6mm)≤W1≤W3; (L5+3mm)≤L1≤W4.

6. The lithium battery cell according to claim 1, wherein: Also includes: a cathode protection adhesive layer; the cathode active material layer has a third region, the third region is etched with a plurality of second grooves, and the plurality of second grooves are arranged in parallel and spaced apart; One side surface of the cathode protection rubber layer is attached to the third area, and the other side surface of the cathode protection rubber layer covers the outer side of the cathode tab.

7. The lithium battery cell according to claim 6, wherein: Set the width of the third region to W2, the length of the second region to L2, the width of the lithium battery cell to W3, the width of the cathode current collector to W4, the width of the cathode protection glue layer to W6, and the length of the cathode protection glue layer to L6; Among them, (W6+6mm)≤W2≤W3; (L6+3mm)≤L2≤W4.

8. The lithium battery cell according to claim 1, wherein: It also includes: an anode protection glue layer; the cathode active material layer has a fourth area, the fourth area is etched with a plurality of third grooves, and the plurality of third grooves are arranged in parallel and spaced apart; one side of the anode protection glue layer is attached to the fourth area, and the other side of the anode protection glue layer covers the outside of the anode ear.

9. The lithium battery cell according to claim 1, wherein: The anode current collector is copper foil; the cathode current collector is aluminum foil.

10. A lithium-ion battery, characterized in that include: A lithium battery cell, an electrolyte, and an insulating layer for insulation and through which lithium ions can pass according to any one of claims 1 to 9; the electrolyte is filled between the cathode current collector and the anode current collector, and the insulating layer is provided between the cathode current collector and the anode current collector.

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