Cylindrical battery cell and cylindrical battery

Abstract

The cylindrical battery comprises a shell and the cylindrical battery cell, the cylindrical battery cell comprises a roll core body, a cavity channel extending in the height direction of the roll core body is formed in the roll core body, annular grooves are formed in the two sides of the roll core body in the height direction of the roll core body respectively, and through holes are formed in the bottoms of the annular grooves; in the thickness direction of the roll core body, the outer peripheral wall of the roll core body sinks towards the direction close to the cavity to form an outer flow guide groove, the inner peripheral wall of the roll core body sinks towards the direction away from the cavity to form an inner flow guide groove, and the outer flow guide groove and the inner flow guide groove are both located in the middle of the roll core body in the height direction of the roll core body. The cylindrical battery cell is provided with the annular groove, the outer diversion trench and the inner diversion trench, so that in the liquid injection process, the infiltration effect of the cylindrical battery cell is better, and the production efficiency is higher.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and more specifically, to a cylindrical battery cell and a cylindrical battery. Background Art

[0002] Cylindrical batteries are devices that can convert chemical energy into electrical energy and are widely used in various fields. Cylindrical batteries include a shell and a cylindrical battery cell. The interior of the shell forms a receiving cavity for the cylindrical battery cell to be placed. The receiving cavity is also injected with electrolyte. The infiltration effect of the electrolyte on the cylindrical battery cell directly affects the cycle performance and electrochemical performance of the cylindrical battery.

[0003] Existing cylindrical battery cells include multiple layers of pole pieces and multiple layers of separators. The pole pieces and separators are stacked on top of each other and wound into a cylindrical structure. The gaps between the layers are small, making it difficult for the electrolyte to penetrate the interior of the cylindrical battery cell in a short period of time during the injection process of the cylindrical battery, resulting in the need for repeated injection in the cylindrical battery.

[0004] Since repeated injections are likely to cause partial loss of electrolyte, the uniformity of the injection amount of the cylindrical battery is poor, and in subsequent processes, it is necessary to replenish or remove liquid from cylindrical batteries with less or more injection amounts. Therefore, there are problems such as poor wetting effect of cylindrical batteries and low production efficiency. Utility Model Content

[0005] One of the purposes of the embodiments of the present application is to provide a cylindrical battery cell and a cylindrical battery to solve the technical problem in the prior art that the various layers of pole pieces and the various layers of separators of the cylindrical battery cell are stacked on each other and wound into a cylindrical structure, and the gaps between the layers are small, resulting in the need for repeated injections during the injection process, resulting in poor wetting effect of the cylindrical battery cell and low production efficiency.

[0006] To solve the above technical problems, in the first aspect, an embodiment of the present application provides a cylindrical battery core, which includes a core body, a cavity extending along its height direction is formed inside the core body; along the height direction of the core body, annular grooves are respectively formed on both sides of the core body, and the bottom of the annular groove has a through hole, which is connected to the cavity; along the thickness direction of the core body, the outer peripheral wall of the core body is recessed in the direction adjacent to the cavity to form an outer guide groove, and the inner peripheral wall of the core body is recessed in the direction away from the cavity to form an inner guide groove; the outer guide groove and the inner guide groove are both located in the middle position of the core body along its height direction.

[0007] The cylindrical battery cell provided by the present application has the beneficial effect that: by setting through holes on both sides of the core body, the electrolyte can enter the cavity from the through holes to infiltrate the inner circumferential wall of the core body. Compared with the cylindrical battery cell in the prior art, the core body of the present application has an annular groove, an outer guide groove and an inner guide groove. In the liquid injection process, more flow channels can be provided for electrolyte circulation to improve the liquid absorption capacity of the core body, shorten the liquid injection time, thereby improving the liquid injection efficiency and having high production efficiency; the outer guide groove and the inner guide groove are both located in the middle position of the core body along its height direction, so that the electrolyte can more fully infiltrate the interior of the core body to ensure the uniformity of the infiltration effect and better infiltration effect; the outer guide groove and the inner guide groove can also improve the heat dissipation effect of the middle position of the core body, significantly reduce the temperature rise caused by this position during high-rate testing, and is beneficial to improving the performance of the cylindrical battery cell.

[0008] In a feasible technical solution, the winding core body includes a positive electrode sheet and a negative electrode sheet that are stacked and wound, and the positive electrode sheet is wound with the surface facing away from the negative electrode sheet to form the cavity. The positive electrode sheet and the negative electrode sheet are both in the form of long strips, and the width direction of the positive electrode sheet and the width direction of the negative electrode sheet are parallel to the height direction of the winding core body.

[0009] By adopting such a design, the structure of the winding core body is simple, the processing and manufacturing are convenient, and the production efficiency is high.

[0010] In a feasible technical solution, the width of the positive electrode sheet is smaller than that of the negative electrode sheet, and both side edges of the negative electrode sheet along its width direction protrude relative to both side edges of the positive electrode sheet along its width direction to form the annular groove.

[0011] By adopting such a design, during the injection process, the annular groove can store part of the electrolyte to prolong the contact time between the electrolyte and the edges of the positive electrode sheet and the negative electrode sheet along the height direction of the cylindrical battery cell, thereby improving the wetting effect.

[0012] In a feasible technical solution, the positive electrode sheet has a first notch and a second notch on both side edges along its length direction, and the negative electrode sheet has a third notch and a fourth notch on both side edges along its length direction, respectively. The first notch and the third notch are arranged in alignment to form the outer guide groove, and the second notch and the fourth notch are arranged in alignment to form the inner guide groove.

[0013] In a feasible technical solution, the first notch and the second notch both extend along the length direction of the positive electrode sheet, the third notch and the fourth notch both extend along the length direction of the negative electrode sheet, the length of the first notch is smaller than the length of the third notch, and the length of the second notch is smaller than the length of the fourth notch.

[0014] In a feasible technical solution, the first notch and the second notch are both located at 1 / 4-1 / 2 of the width of the positive electrode sheet; the third notch and the fourth notch are both located at 1 / 4-1 / 2 of the width of the negative electrode sheet.

[0015] In a feasible technical solution, the first notch and the second notch are located at the same horizontal position of the positive electrode sheet along its width; the third notch and the fourth notch are located at the same horizontal position of the negative electrode sheet along its width.

[0016] In an achievable technical solution, the length of the positive electrode sheet is a, the length of the negative electrode sheet is a+b, the sum of the lengths of the first notch and the second notch is c, and the sum of the lengths of the third notch and the fourth notch is d, wherein a / 6≤c≤a / 2, a / 6+e≤d≤a / 2+e, and b and e are both positive numbers.

[0017] In a feasible technical solution, the cylindrical battery cell further includes a positive electrode ear and a negative electrode ear, wherein the positive electrode ear and the negative electrode ear are respectively located on both sides of the winding core body along its height direction, the positive electrode ear is connected to the positive electrode sheet, and the negative electrode ear is connected to the negative electrode sheet.

[0018] In a second aspect, an embodiment of the present application further provides a cylindrical battery, comprising a housing and the above-mentioned cylindrical battery cell, wherein a receiving cavity is formed inside the housing for placing the cylindrical battery cell.

[0019] The beneficial effect of the cylindrical battery provided in the present application is that by providing the above-mentioned cylindrical battery core, the cycle life of the cylindrical battery can be improved and the performance of the cylindrical battery is more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0021] Figure 1 A schematic diagram of the structure of a cylindrical battery cell provided in an embodiment of the present application;

[0022] Figure 2 A cross-sectional view of a cylindrical battery cell in an embodiment of the present application;

[0023] Figure 3 This is a schematic diagram of the structure after the positive electrode sheet is laid flat in the embodiment of the present application;

[0024] Figure 4This is a schematic diagram of the structure after the negative electrode sheet is laid flat in the embodiment of the present application.

[0025] Among them, the reference numerals in the figure are:

[0026] 10. winding core body; 11. positive electrode sheet; 12. negative electrode sheet; 101. cavity; 102. annular groove; 103. through hole; 104. outer guide groove; 105. inner guide groove; 106. first notch; 107. second notch; 108. third notch; 109. fourth notch;

[0027] 20. Positive electrode ear;

[0028] 30. Negative ear. DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0030] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0031] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0033] exist Figure 1-Figure 4 In the figure, the X-axis direction is the “height direction of the core body 10 ”.

[0034] The following is a detailed description with reference to the accompanying drawings and embodiments:

[0035] Please also read Figures 1 to 4 The embodiment of the present application provides a cylindrical battery cell, which includes a core body 10. A cavity 101 extending along its height direction is formed inside the core body 10. Annular grooves 102 are formed on both sides of the core body 10 along the height direction of the core body 10. The bottom of the annular groove 102 has a through hole 103, which is connected to the cavity 101. Along the thickness direction of the core body 10, the outer peripheral wall of the core body 10 is recessed toward the direction adjacent to the cavity 101 to form an outer guide groove 104, and the inner peripheral wall of the core body 10 is recessed toward the direction away from the cavity 101 to form an inner guide groove 105. The outer guide groove 104 and the inner guide groove 105 are both located in the middle position of the core body 10 along its height direction.

[0036] By setting through holes 103 on both sides of the core body 10, the electrolyte can enter the cavity 101 from the through holes 103 to infiltrate the inner wall of the core body 10. The core body 10 has an annular groove 102, an outer guide groove 104 and an inner guide groove 105. In the injection process, more flow channels can be provided for electrolyte circulation to improve the liquid absorption capacity of the core body 10, shorten the injection time, and thus improve the injection efficiency, with high production efficiency; the outer guide groove 104 and the inner guide groove 105 are both located in the middle position of the core body 10 along its height direction, so that the electrolyte can more fully infiltrate the inside of the core body 10 to ensure the uniformity of the infiltration effect and better infiltration effect; the outer guide groove 104 and the inner guide groove 105 can also improve the heat dissipation effect of the middle position of the core body 10, significantly reduce the temperature rise caused by this position during high-rate testing, and are more conducive to improving the performance of the cylindrical battery cell.

[0037] In one embodiment, please refer to Figures 1 to 4 The winding core body 10 includes a positive electrode sheet 11 and a negative electrode sheet 12 which are stacked and wound. The surface of the positive electrode sheet 11 facing away from the negative electrode sheet 12 is wound to form a cavity 101. The positive electrode sheet 11 and the negative electrode sheet 12 are both in a long strip structure. The width direction of the positive electrode sheet 11 and the width direction of the negative electrode sheet 12 are parallel to the height direction of the winding core body 10.

[0038] In application, the positive electrode sheet 11 and the negative electrode sheet 12 are both rectangular structures, and the core body 10 also includes a first separator and a second separator. The first separator is located between the positive electrode sheet 11 and the negative electrode sheet 12, and the second separator is located on the side of the negative electrode sheet 12 away from the positive electrode sheet 11. The positive electrode sheet 11, the first separator, the negative electrode sheet 12 and the second separator are stacked and wound to form the core body 10. The core body 10 has a simple structure, is easy to process and manufacture, and has high production efficiency.

[0039] Specifically, the positive electrode sheet 11 is prepared by coating lithium tribasic acid with aluminum foil, and the negative electrode sheet 12 is prepared by coating graphite slurry with copper foil.

[0040] In one embodiment, please refer to Figures 1 to 4 The width of the positive electrode sheet 11 is smaller than that of the negative electrode sheet 12 , and both side edges of the negative electrode sheet 12 along its width direction protrude relative to both side edges of the positive electrode sheet 11 along its width direction to form an annular groove 102 .

[0041] In application, during the injection process, the annular groove 102 can store part of the electrolyte to prolong the contact time between the positive electrode sheet 11 and the negative electrode sheet 12 and the electrolyte along the height direction of the winding core body 10, thereby improving the wetting effect.

[0042] In one embodiment, please refer to Figures 1 to 4 The positive electrode sheet 11 has a first notch 106 and a second notch 107 on both side edges along its length direction, and the negative electrode sheet 12 has a third notch 108 and a fourth notch 109 on both side edges along its length direction, the first notch 106 and the third notch 108 are arranged in alignment to form an outer guide groove 104, and the second notch 107 and the fourth notch 109 are arranged in alignment to form an inner guide groove 105.

[0043] In application, a mold is used to die-cut the positive electrode sheet 11 and the negative electrode sheet 12 to cut out the first notch 106, the second notch 107, the third notch 108 and the fourth notch 109. The cut positive electrode sheet 11 and negative electrode sheet 12 are stacked so that the first notch 106 is aligned with the third notch 108, and the second notch 107 is aligned with the fourth notch 109. The stacked positive electrode sheet 11 and negative electrode sheet 12 are then wound to form a winding core body 10 with an outer guide groove 104 and an inner guide groove 105.

[0044] Specifically, in an example of the present application, the first notch 106 and the third notch 108 have the same shape, and the first notch 106 can be one of square, triangle, and ellipse; the second notch 107 and the fourth notch 109 have the same shape, and the second notch 107 can be one of square, triangle, and ellipse.

[0045] Specifically, in another example of the present application, the first notch 106 , the second notch 107 , the third notch 108 and the fourth notch 109 have the same shape, and the first notch 106 can be one of square, triangle and ellipse.

[0046] In one embodiment, please refer to Figures 1 to 4 The first notch 106 and the second notch 107 both extend along the length direction of the positive electrode sheet 11 , the third notch 108 and the fourth notch 109 both extend along the length direction of the negative electrode sheet 12 , the length of the first notch 106 is smaller than the length of the third notch 108 , and the length of the second notch 107 is smaller than the length of the fourth notch 109 .

[0047] In application, by adopting such a design, the flow resistance of the electrolyte at the aligned portions of the first notch 106 and the third notch 108 and the second notch 107 and the fourth notch 109 can be reduced, so as to increase the infiltration speed of the electrolyte.

[0048] In one embodiment, please refer to Figures 1 to 4 The first notch 106 and the second notch 107 are both located at 1 / 4-1 / 2 of the width of the positive electrode sheet 11 ; the third notch 108 and the fourth notch 109 are both located at 1 / 4-1 / 2 of the width of the negative electrode sheet 12 .

[0049] In application, by adopting such a design, the stress concentration problem in the middle of the core body 10 can be alleviated, which is beneficial to improving the dynamic performance of the cylindrical battery cell in this area, so as to improve the problem of sodium or lithium precipitation in the cylindrical battery cell.

[0050] In one embodiment, please refer to Figures 1 to 4 The first notch 106 and the second notch 107 are located at the same horizontal position of the positive electrode sheet 11 along its width; the third notch 108 and the fourth notch 109 are located at the same horizontal position of the negative electrode sheet 12 along its width.

[0051] In application, by adopting such a design, the die-cutting operation of the positive electrode sheet 11 and the negative electrode sheet 12 is more convenient, and the production efficiency is further improved.

[0052] In one embodiment, please refer to Figures 1 to 4 The length of the positive electrode sheet 11 is a, the length of the negative electrode sheet 12 is a+b, the sum of the lengths of the first notch 106 and the second notch 107 is c, and the sum of the lengths of the third notch 108 and the fourth notch 109 is d, wherein a / 6≤c≤a / 2, a / 6+e≤d≤a / 2+e, and b and e are both positive numbers.

[0053] In application, 2500 mm≤a≤2800 mm, b=40 mm, e=2 mm, so as to ensure that the negative electrode sheet 12 can cover the positive electrode sheet 11 in the winding core body 10 .

[0054] In one embodiment, please refer to Figures 1 to 4 The cylindrical battery cell also includes a positive electrode ear 20 and a negative electrode ear 30 , which are respectively located on both sides of the winding core body 10 along its height direction. The positive electrode ear 20 is connected to the positive electrode sheet 11 , and the negative electrode ear 30 is connected to the negative electrode sheet 12 .

[0055] In application, the positive electrode tab 20 is made of aluminum, and the negative electrode tab 30 is made of nickel or copper-plated nickel to ensure the electrical performance of the cylindrical battery cell.

[0056] Please also read Figures 1 to 4The present application also provides a cylindrical battery, including a shell and the above-mentioned cylindrical battery cell, and a receiving cavity is formed inside the shell for placing the cylindrical battery cell.

[0057] In application, by providing the above cylindrical battery cells, the cycle life of the cylindrical battery can be improved and the performance of the cylindrical battery can be more stable.

[0058] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A cylindrical battery cell, characterized in that: It comprises a winding core body (10), wherein a cavity (101) extending along the height direction thereof is formed inside the winding core body (10); Along the height direction of the winding core body (10), annular grooves (102) are respectively formed on both sides of the winding core body (10), and the bottom of the annular groove (102) has a through hole (103), and the through hole (103) is connected to the cavity (101); Along the thickness direction of the core body (10), the outer peripheral wall of the core body (10) is recessed in a direction close to the cavity (101) to form an outer guide groove (104), and the inner peripheral wall of the core body (10) is recessed in a direction away from the cavity (101) to form an inner guide groove (105); The outer guide groove (104) and the inner guide groove (105) are both located in the middle of the winding core body (10) along its height direction.

2. The cylindrical battery cell according to claim 1, characterized in that: The winding core body (10) comprises a positive electrode sheet (11) and a negative electrode sheet (12) which are stacked and wound, the positive electrode sheet (11) is wound with its surface facing away from the negative electrode sheet (12) to form the cavity (101), the positive electrode sheet (11) and the negative electrode sheet (12) are both in the form of long strips, and the width direction of the positive electrode sheet (11) and the width direction of the negative electrode sheet (12) are both parallel to the height direction of the winding core body (10).

3. The cylindrical battery cell according to claim 2, characterized in that: The width of the positive electrode sheet (11) is smaller than that of the negative electrode sheet (12), and the two side edges of the negative electrode sheet (12) along its width direction protrude relative to the two side edges of the positive electrode sheet (11) along its width direction to form the annular groove (102).

4. The cylindrical battery cell according to claim 2, characterized in that: The positive electrode sheet (11) has a first notch (106) and a second notch (107) at both side edges along its length direction, and the negative electrode sheet (12) has a third notch (108) and a fourth notch (109) at both side edges along its length direction, the first notch (106) and the third notch (108) are arranged in alignment to form the outer guide groove (104), and the second notch (107) and the fourth notch (109) are arranged in alignment to form the inner guide groove (105).

5. The cylindrical battery cell according to claim 4, characterized in that: The first notch (106) and the second notch (107) both extend along the length direction of the positive electrode sheet (11), the third notch (108) and the fourth notch (109) both extend along the length direction of the negative electrode sheet (12), the length of the first notch (106) is smaller than the length of the third notch (108), and the length of the second notch (107) is smaller than the length of the fourth notch (109).

6. The cylindrical battery cell according to claim 4, characterized in that: The first notch (106) and the second notch (107) are both located at 1 / 4 to 1 / 2 of the width of the positive electrode sheet (11); the third notch (108) and the fourth notch (109) are both located at 1 / 4 to 1 / 2 of the width of the negative electrode sheet (12).

7. The cylindrical battery cell according to claim 4, characterized in that: The first notch (106) and the second notch (107) are located at the same horizontal position of the positive electrode sheet (11) along its width; the third notch (108) and the fourth notch (109) are located at the same horizontal position of the negative electrode sheet (12) along its width.

8. The cylindrical battery cell according to claim 4, characterized in that: The length of the positive electrode sheet (11) is a, the length of the negative electrode sheet (12) is a+b, the sum of the lengths of the first notch (106) and the second notch (107) is c, and the sum of the lengths of the third notch (108) and the fourth notch (109) is d, wherein a / 6≤c≤a / 2, a / 6+e≤d≤a / 2+e, and b and e are both positive numbers.

9. The cylindrical battery cell according to claim 2, characterized in that: The cylindrical battery cell further comprises a positive electrode ear (20) and a negative electrode ear (30), wherein the positive electrode ear (20) and the negative electrode ear (30) are respectively located on both sides of the winding core body (10) along its height direction, the positive electrode ear (20) is connected to the positive electrode sheet (11), and the negative electrode ear (30) is connected to the negative electrode sheet (12).

10. A cylindrical battery, characterized in that: It comprises a shell and the cylindrical battery cell according to any one of claims 1 to 9, wherein a receiving cavity is formed inside the shell for placing the cylindrical battery cell.

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