Cylindrical full-tab lithium ion positive plate, battery roll core and battery

Abstract

The utility model discloses a cylindrical full-tab lithium ion positive plate, a battery roll core and a battery, and belongs to the technical field of batteries. The battery roll core is formed by winding a positive plate, a diaphragm, a negative plate and a diaphragm, and the battery is manufactured through the procedures of assembling, baking, liquid injection, formation and sealing in sequence; longitudinal grooves are respectively formed in two side surfaces of the positive plate and penetrate through the length of the positive plate; the full-tab cylindrical battery is suitable for a battery manufacturing process, gas-liquid circulation between the interior of a battery roll core and a roll core center hole is realized through the slotting design of the positive plate, and the problems of difficulty in infiltrating the interior of the roll core from two ends, low liquid injection efficiency, long electrolyte infiltrating time and the like of an existing full-tab cylindrical battery are effectively solved.

Description

Technical Field

[0001] The utility model relates to a cylindrical full-ear lithium-ion positive electrode sheet, a battery coil core and a battery, belonging to the technical field of batteries. Background Art

[0002] The large cylindrical battery pole ears in the prior art usually adopt the full pole ear method. During the electrode coating process, an empty foil flattening area is left on the edge. Multiple groups of pole ears are stacked to form a battery core with empty foil flattening areas at both ends. The empty foils at both ends of the battery core are flattened and then welded using a collector plate welding machine. Since the empty foils at both ends of the battery core are relatively dense after being flattened, the baking time is long, and it is difficult for the electrolyte to infiltrate from the two ends of the battery core to the inside of the core, which further causes low electrolyte injection efficiency, long electrolyte infiltration time, and less electrolyte inside the core, thereby increasing the production cost of lithium batteries, reducing the rate performance and discharge capacity of finished lithium batteries, and shortening the service life of finished lithium batteries. Utility Model Content

[0003] Purpose of the utility model: In order to overcome the deficiencies in the prior art, the utility model provides a cylindrical full-ear lithium-ion positive electrode sheet, a battery roll core and a battery. The utility model provides a groove on each positive electrode sheet so that the inside of the battery electrode sheet of the roll core and the central hole maintain gas-liquid circulation, which effectively solves the current problems of the full-ear cylindrical battery electrolyte being difficult to infiltrate the inside of the roll core from both ends, the low injection efficiency, and the long electrolyte infiltration time.

[0004] In order to achieve the above purpose / solve the above technical problems, the utility model is implemented by adopting the following technical solutions:

[0005] A cylindrical full-ear lithium-ion positive electrode sheet, wherein longitudinal grooves for passing electrolyte are respectively provided on both side surfaces of the positive electrode sheet.

[0006] Optionally, the longitudinal groove evenly divides the side surface of the positive electrode sheet, and the grooves on the two side surfaces are not opposite to each other.

[0007] Optionally, the cross-sectional shape of the longitudinal groove is any one of an inverted trapezoid, a rectangle, and a semi-ellipse.

[0008] Optionally, the depth of the longitudinal groove is 1 / 2-3 / 4 of the thickness of the positive electrode dressing layer, and the width of the longitudinal groove is 0.3-1 mm.

[0009] A battery roll core, wherein the positive electrode sheet of the battery roll core is the above-mentioned positive electrode sheet, and the groove of the positive electrode sheet is connected to the central hole of the battery roll core.

[0010] Optionally, one end of the battery coil core is connected to a positive current collecting disk via a positive electrode tab, and the other end is connected to a negative current collecting disk via a negative electrode tab; the positive current collecting disk and the negative current collecting disk are respectively provided with through holes for flow with the center hole.

[0011] A battery comprises the battery coil core mentioned above.

[0012] Compared with the prior art, the utility model has the following beneficial effects:

[0013] By opening grooves on each positive electrode sheet, after the positive electrode sheet, diaphragm, negative electrode sheet and diaphragm are wound to form a battery core, multiple grooves form a channel from the inside of the core to the center hole, so that the battery electrode sheet and the center hole maintain gas-liquid circulation, effectively solving the current problems of full-pole lug cylindrical battery electrolyte infiltration into the core from both ends, low injection efficiency, long electrolyte infiltration time, etc., further improving the lithium battery production efficiency, the qualified rate of finished lithium batteries, extending the service life, and saving lithium battery production costs.

[0014] Secondly, the grooves evenly divide the side of the positive electrode sheet laterally, and the grooves on the two sides are not opposite to each other, so that when the core is infiltrated, it is convenient to evenly inject the electrolyte into the core from multiple different positions, so as to achieve the purpose of fully infiltrating the core.

[0015] The utility model has an improved and simplified structure, is easy to process, has a good effect and high efficiency, and can effectively improve the problems of difficult liquid injection and difficult wetting of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Shown is a schematic diagram of a cylindrical full-tab lithium-ion positive electrode sheet of the utility model;

[0017] Figure 2 Shown is a cross-sectional view of the positive electrode sheet of the utility model;

[0018] Figure 3 Shown is a cross-sectional view of the battery roll core of the utility model;

[0019] Figure 4 Shown Figure 3 A local enlarged view of point A in the middle.

[0020] Figure numerals: 1-longitudinal groove; 2-flattened area of ​​positive electrode sheet empty foil; 3-positive electrode aluminum foil; 4-positive electrode ear; 5-positive electrode dressing layer; 6-negative electrode dressing layer; 7-negative electrode copper foil; 8-diaphragm; 9-battery roll core; 10-center hole. DETAILED DESCRIPTION

[0021] The utility model is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the utility model, and cannot be used to limit the protection scope of the utility model.

[0022] Combination Figure 1 to Figure 2 The cylindrical full-ear lithium-ion positive electrode sheet of the utility model is further explained, wherein longitudinal grooves 1 are respectively opened on both side surfaces of the middle part of the positive electrode sheet, and the longitudinal grooves 1 are used for gas-liquid circulation between the electrode sheet located in the battery coil core 9 and the central hole 10. The slot design of this embodiment effectively solves the current problems of the full-ear cylindrical battery electrolyte being difficult to infiltrate the interior of the coil core from both ends, the low injection efficiency, and the long electrolyte infiltration time.

[0023] Preferably, the positive electrode sheet includes: a positive electrode aluminum foil 3, a positive electrode dressing layer 5 coated on both sides of the positive electrode aluminum foil 3, a positive electrode sheet empty foil flattened area 2 arranged at one end of the positive electrode aluminum foil 3 and located on the same side of the positive electrode dressing layer 5, and a positive electrode ear 4 arranged in the positive electrode sheet empty foil flattened area 2. In this embodiment, the positive electrode ear 4 is externally connected to the positive electrode current collecting disk.

[0024] Preferably, the negative electrode sheet includes: a negative electrode copper foil 7, a negative electrode dressing layer 6 coated on both sides of the copper foil, a negative electrode sheet empty foil flattened area arranged at one end of the negative electrode copper foil 7 and located on the same side of the negative electrode dressing layer 6, and a negative electrode ear arranged in the empty foil flattened area of ​​the negative electrode sheet. In this embodiment, the negative electrode ear is externally connected to the negative electrode current collecting plate.

[0025] Preferably, the longitudinal grooves 1 are distributed on both sides of the positive electrode sheet, running through the entire positive electrode sheet, and the positions of the grooves are staggered, so that when the core is infiltrated, it is convenient for the electrolyte to be evenly injected into the core from multiple different positions to achieve the purpose of sufficient infiltration.

[0026] Preferably, the cross-sectional shape of the longitudinal groove 1 is an inverted trapezoid, a rectangle, or a semi-ellipse, but is not limited thereto. In this embodiment, the longitudinal groove 1 can be processed by laser cutting, or other refined cutting processes can be used for slotting design.

[0027] Preferably, the depth of the longitudinal groove 1 is 1 / 2-3 / 4 of the thickness of the positive electrode dressing layer 5, and the width of the longitudinal groove 1 is 0.3-1 mm.

[0028] Preferably, the number of longitudinal grooves 1 on each side of the positive electrode sheet is 1-2, and in the present embodiment, the multiple grooves 1 evenly divide the side of the positive electrode sheet horizontally, and the grooves 1 on the two sides are not opposite to each other, which further increases the injection channel of the electrolyte when the core is infiltrated, accelerates the infiltration speed, and shortens the infiltration time.

[0029] Combination Figure 3 to Figure 4 The battery roll core 9 in this embodiment is further described. The positive electrode sheet of the battery roll core 9 is the positive electrode sheet mentioned above, and the groove 1 of the positive electrode sheet is connected to the central hole of the battery roll core.

[0030] Preferably, one end of the battery core 9 is connected to the positive current collector disk through the positive electrode tab 4, and the other end is connected to the negative current collector disk through the negative electrode tab; the positive current collector disk and the negative current collector disk are respectively provided with through holes for communicating with the center hole 10, so that the electrolyte can infiltrate the interior of the core from both ends.

[0031] In addition, a battery made of the above-mentioned battery roll core 9 is further described, and the battery electrodes include positive electrodes and negative electrodes. The multi-layer positive electrodes are stacked with the diaphragm 8 and the negative electrodes to form a mixed layer, and the battery is manufactured through winding, assembly, baking, liquid injection, formation, and sealing processes in sequence.

[0032] Working principle:

[0033] The multi-layer positive electrode sheets for winding are all grooved, so that longitudinal grooves 1 are distributed on both sides of each layer of positive electrode sheets. The multi-layer positive electrode sheets are stacked with the separator 8 and the negative electrode sheets respectively, and then wound to form a battery core 9. A central hole 10 is provided inside the battery core 9. The central hole 10 is connected to the longitudinal groove 1 port inside the battery core 9 to achieve gas-liquid circulation between the battery core 9 and the central hole 10. Compared with the traditional liquid injection method, the slot design of this embodiment increases the number of liquid injection ports and the central hole inside the battery core, which effectively solves the current problems of difficulty in infiltrating the core from both ends of the full-ear cylindrical battery electrolyte, low injection efficiency, and long electrolyte infiltration time.

[0034] In addition, the battery roll core 9 of the present invention is connected to the positive and negative current collecting disks, and both the positive and negative current collecting disks can flow with the central hole 10, further improving the injection efficiency of the electrolyte infiltrating the interior of the roll core from both ends.

[0035] In summary, the utility model, by opening grooves on each positive electrode sheet, multiple electrode sheets are wound to form a battery core 9, and at the same time, multiple grooves constitute a channel extending from the inside of the core to the center hole 10, so that the inside of the core and the center hole 10 maintain gas-liquid circulation, effectively solving the current problems of full-ear cylindrical battery electrolyte infiltration from both ends The inside of the core is difficult, the injection efficiency is low, and the electrolyte infiltration time is long. The problems further improve the lithium battery production efficiency, the qualified rate of finished lithium batteries, and the service life is extended, and the production cost of lithium batteries is saved; and the structure of the utility model is improved and streamlined, the processing is simple, the effect is good, and the efficiency is high, which can effectively improve the battery injection and infiltration problems.

[0036] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

Claims

1. A cylindrical full-ear lithium-ion positive electrode sheet, characterized in that: The two side surfaces of the positive electrode sheet are respectively provided with longitudinal grooves for passing electrolyte.

2. The cylindrical full-tab lithium-ion positive electrode sheet according to claim 1, characterized in that: The longitudinal groove evenly divides the side surface of the positive electrode sheet in the transverse direction, and the longitudinal grooves on the two side surfaces are not opposite to each other.

3. The cylindrical full-tab lithium-ion positive electrode sheet according to claim 1, characterized in that: The cross-sectional shape of the longitudinal groove is any one of an inverted trapezoid, a rectangle, and a semi-ellipse.

4. The cylindrical full-tab lithium-ion positive electrode sheet according to claim 1, characterized in that: The depth of the longitudinal groove is 1 / 2-3 / 4 of the thickness of the positive electrode dressing layer, and the width of the longitudinal groove is 0.3-1 mm.

5. A battery roll core, characterized in that: The positive electrode sheet of the battery roll core is the positive electrode sheet according to any one of claims 1 to 4, and the groove of the positive electrode sheet is connected to the central hole of the battery roll core.

6. The battery roll core according to claim 5, characterized in that: One end of the battery coil core is connected to the positive current collecting disk through the positive electrode tab, and the other end is connected to the negative current collecting disk through the negative electrode tab; the positive current collecting disk and the negative current collecting disk are respectively provided with through holes for flow with the central hole.

7. A battery, characterized in that: A battery roll core comprising the battery roll core according to any one of claims 5 to 6.

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