CN219350321U

CN219350321U - Single battery and battery pack

Info

Publication number: CN219350321U
Application number: CN202320234661.5U
Authority: CN
Inventors: 赵学伟
Original assignee: Sunwoda Electric Vehicle Battery Co Ltd
Current assignee: Xinwangda Power Technology Co ltd
Priority date: 2023-02-02
Filing date: 2023-02-02
Publication date: 2023-07-14
Anticipated expiration: 2033-02-02

Abstract

The embodiment of the application discloses battery cell and battery package, battery cell is through setting up the support in the casing, the support includes main part and supporting part, the main part overlaps along the direction of height of casing with the body of electric core, in width direction, the side of electric core body is close to and has the fit clearance between main part one end and the casing, the extrusion part protrusion sets up in deviating from the top cap one side in the main part, and extrusion part inserts and locates the fit clearance and all looks butt with side and casing, make extrusion part and the side of the tight electric core body of casing cooperation clamp be close to main part one end, in follow-up charge-discharge cycle in-process, guarantee the pole piece closely laminating in the electric core body, make electric core capacity obtain full play, promote battery cell's circulation capacity retention rate, improve battery cell life.

Description

Single battery and battery pack

Technical Field

The application relates to the technical field of batteries, in particular to a single battery and a battery pack.

Background

New energy automobiles enter a high-speed development stage, and a power battery is used as an energy source of the electric automobile to play a role in importance. At present, the novel battery technology is endless, and CTP (Cell To Pack) is used as a technology for directly integrating an electric core into a battery Pack, so that the use amount of parts is greatly reduced, the manufacturing cost of a power battery is reduced, and the energy density of the battery Pack is further improved. The long cell is used as a battery unit in a single battery in CTP, and is obviously different from a conventional square cell in design and manufacture. The long battery cell is formed by stacking positive plate, diaphragm and negative plate in proper order and is laminated the design, because the pole piece is longer, lead to there is the attenuate region at the both ends of long battery cell after the coating, lead to the positive plate in this region, diaphragm and negative plate laminating inseparable, active metal ion takes off and inlays inadequately in the charge-discharge cyclic process, influences the full play of battery cell capacity.

Disclosure of Invention

The embodiment of the application provides a single battery and a battery pack, which can solve the problem that the performance of the single battery is reduced due to the fact that the lamination of a pole piece of a battery core in a thinning area is not tight in the existing single battery.

The embodiment of the application provides a single battery, which comprises: a housing provided with an opening, the housing having a width direction and a height direction orthogonal to each other; the top cover is covered on the opening; further comprises: the battery cell body is arranged in the shell and is provided with two side surfaces which are oppositely arranged along the width direction; the battery cell body, the main body part and the top cover are overlapped along the height direction, and the extrusion part is arranged on one surface of the main body part, which is away from the top cover, and extends in a direction away from the main body part; and in the width direction, an assembly gap is formed between one end, close to the main body, of the side surface and the shell, and the extrusion part is inserted into the assembly gap and is connected with the side surface and the shell.

Optionally, the assembly gap has a first distance along the width direction, and the first distance decreases from an end closer to the main body portion to an end farther from the main body portion along the height direction.

Optionally, the pressing portion has a thickness in the width direction, the thickness decreasing in the height direction from a connecting end of the pressing portion with the main body portion toward a direction away from the main body portion.

Optionally, the extrusion part includes a first extrusion part and a second extrusion part, the first extrusion part and the second extrusion part are arranged at two ends of the main body part at intervals along the width direction, and the battery cell body is clamped between the first extrusion part and the second extrusion part; two assembly gaps are defined between the two side surfaces and the shell, and the first extrusion part and the second extrusion part are respectively inserted into the two assembly gaps.

Optionally, the main body part is provided with at least one opening, and the opening penetrates through the main body part along the height direction; the top cover is provided with a liquid injection port for injecting electrolyte, and the liquid injection port is communicated with at least one opening.

Optionally, the support further includes a support portion, the support portion set up in the main part be close to the one side of top cap and towards the top cap extends, the support portion with the top cap offsets.

Optionally, the number of the supporting parts is at least two, and the supporting parts are distributed along the circumferential direction of the main body part.

Optionally, the supporting portion is provided with a through hole penetrating through the supporting portion and the main body portion along the height direction.

Optionally, the battery cell further comprises a tab, wherein the battery cell body is provided with two end faces which are oppositely arranged along the height direction, and the tab is convexly arranged on at least one end face along the height direction; the main body part is provided with an opening for the tab to pass through.

Meanwhile, the embodiment of the application also provides a battery pack which comprises the single battery.

The beneficial effects of this application lie in, provide a battery cell and have battery package of this battery cell, the battery cell is through setting up the support in the casing, the support includes main part and supporting part, the main part overlaps along the direction of height of casing with the body of electric core, in width direction, the side of electric core body is close to and has the fit clearance between main part one end and the casing, the extrusion part protrusion sets up in deviating from the top cap one side in the main part, and the extrusion part is filled in the fit clearance and all meets with side and casing, support the electric core body, make the extrusion part and the side that the casing cooperation pressed from both sides tight electric core body be close to main part one end, in the cyclic process of follow-up charge and discharge, pole piece closely laminating in the electric core body can be guaranteed, make electric core capacity obtain full play, promote battery cell's cyclic capacity retention rate, improve battery cell life-span.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a single battery according to an embodiment of the present disclosure;

FIG. 2 is an enlarged schematic view of the structure at A of FIG. 1;

fig. 3 is a schematic diagram of an assembled structure of a bracket, a battery cell and a housing in a single battery according to an embodiment of the present disclosure;

fig. 4 is a schematic view of a first angle structure of a bracket in a single battery according to an embodiment of the present disclosure;

fig. 5 is a schematic view of a second angle structure of a bracket in a single battery according to an embodiment of the present disclosure;

fig. 6 is a schematic view of a third angle structure of a bracket in a single battery according to an embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of a body of a battery cell in a single battery according to an embodiment of the present disclosure.

Reference numerals illustrate:

100. the battery pack comprises a single battery, 110, a shell, 111, an opening, 120, a battery cell body, 120a, a body section, 120b, a thinning section, 1201, a pole piece, 121, a side surface, 122, an end surface, 130, a bracket, 131, a main body part, 1311, a notch, 1312, an opening, 132, an extrusion part, 132a, a first surface, 132b, a second surface, 1321, a first extrusion part, 1322, a second extrusion part, 133, a supporting part, 1331, a through hole, 140, a top cover, 141, a pole, 142 and a liquid injection port;

x, length direction, Y, width direction, Z, height direction.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application. Furthermore, it should be understood that the detailed description is presented herein for purposes of illustration and explanation only and is not intended to limit the present application. In this application, unless otherwise indicated, terms of orientation such as "upper" and "lower" are used to generally refer to the upper and lower positions of the device in actual use or operation, and specifically the orientation of the drawing figures; while "inner" and "outer" are for the outline of the device. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features.

In the examples of the present application, "parallel" refers to a state in which the angle formed by a straight line and a straight line, a straight line and a plane, or a plane and a plane is-1 ° to 1 °. The terms "perpendicular" and "orthogonal" refer to a state in which the angle formed by a straight line and a straight line, a straight line and a plane, or a plane and a plane is 89 ° to 91 °.

The embodiment of the application provides a battery cell and have this battery cell's battery package, the battery cell is through setting up the support in the casing, the support includes main part and supporting part, the main part overlaps along the direction of height of casing with the body of electric core, in width direction, the side of electric core body is close to and has the fit clearance between main part one end and the casing, the extrusion part protrusion sets up in deviating from the top cap one side in the main part, and the extrusion part inserts and locates the fit clearance and with side and the equal looks butt of casing, make the extrusion part press from both sides tight side of electric core body with the cooperation of casing and be close to main part one end, in follow-up charge-discharge cyclic in-process, guarantee the pole piece closely laminating in the electric core body, make electric core capacity obtain full play, promote battery cell's circulation capacity retention rate. As a typical application, a battery pack including the single battery may be used to supply power to electric equipment such as an electric automobile.

An embodiment of the present application provides a single battery 100, referring to fig. 1 to 7, the single battery 100 includes: housing 110, cell body 120, bracket 130, and top cover 140.

Referring to fig. 1 and 2, the housing 110 is provided with an opening 111, the housing 110 has a width direction Y and a height direction Z orthogonal to each other, and a top cover 140 covers the opening 111 to form a closure of the housing 110 to define a receiving chamber (not shown) within the housing 110.

Referring to fig. 1 to 3, the battery cell body 120 is disposed in the case, specifically, the battery cell body 120 is accommodated in the accommodating cavity, referring to fig. 2 and 7, the battery cell body 120 has two side surfaces 121 disposed opposite to each other in the width direction Y, referring to fig. 1 to 6, the holder 130 is disposed in the case 110, the top cover 140, the holder 130 and the battery cell body 120 are stacked in the height direction Z, the holder 130 includes a main body portion 131 and a pressing portion 132, the pressing portion 132 is disposed on a side of the main body portion 131 facing away from the top cover 140 and extends in a direction away from the main body portion 131, wherein, in the width direction Y, a space exists between an end of the side surface 121 close to the main body portion 131 and an inner side wall of the case 110 adjacent to the main body portion 131, specifically, an assembly space is formed between an end of the side surface 121 of the battery cell body 120 close to the main body portion 131 and an inner side wall of the case 110, the pressing portion 132 is inserted in the assembly space, and the pressing portion 132 is connected to the side surfaces 121 and the inner side wall of the case 110, and the pressing portion 132 forms a pressing of the end of the side surface 121 close to the main body portion 131, so that each pole piece in the battery cell body 120 can be in close contact. It can be understood that the pressing portion 132 is connected to both the side 121 and the housing 110, that is, the pressing portion 132 may be in contact with both the side 121 and the housing 110, or that the pressing portion 132 may be in close contact with both the side 121 and the housing 110, and in this embodiment, the pressing portion 132 is preferably in contact with both the side 121 and the housing 110, so that the pressing portion 132 may reliably press the side 121, thereby avoiding the occurrence of separation of the pressing portion 132 from the side 121 during use.

Referring to fig. 7, the battery cell body 120 includes a plurality of electrode sheets 1201, the plurality of electrode sheets 1201 includes a positive electrode sheet and a negative electrode sheet, a separator (not shown in the drawing) is disposed between the positive electrode sheet and the negative electrode sheet, and the positive electrode sheet, the separator and the negative electrode sheet are stacked along a width direction Y to form a lamination structure, and the electrode sheet includes a current collector and an active material layer coated on a surface of the current collector. In this embodiment, the thinning section 120b is disposed at two ends of the body section 120a, and because the length of the pole piece 1201 is longer, there are thinning regions at two ends of the pole piece 1201 in the length direction (corresponding to the height direction Z of the housing 110) after the active material layer is coated, that is, the thickness of the two ends of the battery core body 120 in the length direction is smaller than the thickness of the middle section of the battery core body 120 in the length direction, so that the thinning section 120b is formed, the positive electrode sheet, the separator and the negative electrode sheet of the thinning section 120b are not tightly attached, and are loose compared with the body section 120a, so that the active metal ions (such as lithium ions) in the active material layer are insufficiently de-embedded in the thinning section 120b in the charge-discharge cycle process, and the capacity exertion of the single battery 100 is affected.

In the embodiment, the extrusion portion 132 fills the assembly gap between the side 121 of the battery cell body 120 and the housing 110, so as to form extrusion on one end of the side 121 near the main body 131, that is, the extrusion portion 132 forms extrusion and clamping on the thinned section 120b of the battery cell body 120, so that the positive electrode sheet, the separator and the negative electrode sheet in the thinned section 120b are tightly attached to each other, active metal ions can be fully extracted from the thinned section 120b during the charge and discharge cycle of the battery cell, and the cycle capacity retention rate of the battery cell 100 is improved, that is, the service life of the battery cell 100 is prolonged.

In this embodiment, the fitting clearance has a first distance in the width direction Y, which decreases from an end closer to the main body 131 to an end farther from the main body 131 in the height direction Z. Specifically, referring to fig. 2 and 7, a space in the width direction Y is provided between the two side surfaces 121 of the battery cell body 120, where the space is the thickness of the battery cell body 120, and in the height direction Z, the space of at least a portion of the battery cell body 120 increases from an end close to the main body 131 to an end far from the main body 131 until the side surface 121 is attached to the inner side wall of the housing 110, so that the battery cell body 120 has a thickness variation, and an assembly gap with a first distance variation is formed between an end of the side surface 121 close to the main body 131 and the housing 110, specifically, the thickness of the thinned section 120b of the battery cell body 120 increases from an end of the battery cell body 120 close to the main body 131 to an interface between the thinned section 120b and the main body section 120a along the height direction Z, so that the side surface 121 in the thinned section 120b has a thickness variation forming a slope or inclined surface, and the side surface 121 in the main body section 120a is a plane and is attached to the inner side wall of the housing 110.

In addition, referring to fig. 2, 5 and 6, the pressing part 132 has a thickness in the width direction Y, which decreases in the height direction Z from the connection end of the pressing part 132 with the main body 131 to a direction away from the main body 131, so that the thickness variation of the pressing part 132 matches with the thickness variation of the battery cell body 120 in the thinning section 120b, thereby the pressing part 132 is closely attached to the side 121 of the battery cell body 120, an effective pressing grip of the thinning section 120b of the battery cell body 120 is formed, and the gradual variation of the thickness of the pressing part 132 can adapt to the thickness variation of both ends of the battery cell body 120 to avoid damage caused by excessive pressing of the battery cell body 120, ensure the close attachment of the positive electrode sheet, the separator sheet and the negative electrode sheet located in the thinning section 120b, and promote the circulation capacity retention rate of the battery cell 100.

Referring to fig. 5, the extruding portion 132 has a first surface 132a and a second surface 132b opposite to each other along the width direction Y, the first surface 132a is an inclined plane, the second surface 132b is a plane, that is, an included angle is formed between the first surface 132a and the height direction Z, the second surface 132b is parallel to the height direction Z, so that the extruding portion 132 has a right triangle cross section along the width direction, the extruding portion 132 forms a wedge-shaped sheet structure, the extruding portion 132 abuts against the side 121 through the first surface 132a to form an extrusion on the side 121, the extruding portion 132 abuts against and abuts against an inner side wall of the housing 110 through the second surface 132b, the housing 110 can form a limit and a constraint on the extruding portion 132, and under the constraint of the housing 110, the extruding effect of the extruding portion 132 on the thinned section 120b of the cell body 120 can be ensured.

In addition, the number of the pressing portions 132 is at least two, two assembling gaps are defined between the two side surfaces 121 and the housing 110, in this embodiment, the pressing portions 132 include a first pressing portion 1321 and a second pressing portion 1322, the first pressing portion 1321 and the second pressing portion 1322 are disposed at two ends of the main body portion 131 in the width direction Y at intervals along the width direction Y, the first pressing portion 1321 and the second pressing portion 1322 cooperate to form a clamp for the two side surfaces 121 of the battery cell body 120, and the first pressing portion 1321 and the second pressing portion 1322 are respectively inserted into the two assembling gaps, so as to improve the stress balance of the battery cell body 120.

Referring to fig. 1, openings 111 are formed at opposite ends of the housing 110 in the height direction Z, a top cover 140 is covered in each opening 111, and two brackets 130 are provided at opposite ends of the battery cell body 120 in the length direction. Referring to fig. 1 and 7, the battery core body 120 has two end faces 122 disposed opposite to each other along the height direction Z, a tab is welded on each end face 122, the tab is connected with the pole piece 1201, the tab and the battery core body 120 form an electrode assembly, referring to fig. 3 and 4, an opening 1312 through which the tab passes is formed in the main body 131, a pole 141 is disposed on the top cover 140, and the electrode assembly is electrically connected with the pole 141 through the tab.

In addition, the housing 110 further has a length direction X orthogonal to the width direction Y and the height direction Z, referring to fig. 3 to 5, two openings 1311 are formed in the main body 131, the two openings 1311 are respectively disposed at two ends of the main body 131 in the length direction X, the opening 1311 penetrates the main body 131 along the height direction Z, referring to fig. 1 and 2, a liquid injection port 142 for injecting electrolyte is formed in the top cover 140, the liquid injection port 142 is communicated with the opening 1311, the opening 1311 is formed, the weight of the main body 131 can be reduced, the weight of the battery cell 100 is further reduced, the weight energy density of the battery pack is improved, and the opening 1311 can facilitate the electrolyte to be injected into the accommodating cavity of the housing 110 through the liquid injection port 142, so that the electrolyte can flow into the battery cell body 120 quickly, and the liquid injection efficiency of the battery cell 100 is improved. Note that, the liquid injection port 142 is communicated with the opening 1311, which may be understood that the liquid injection port 142 is communicated with the opening 1311 through a corresponding channel or cavity, or may be directly communicated with the opening 1311.

In this embodiment, along the height direction Z, the projection of the liquid injection port 142 and the projection of the notch 1311 are at least partially overlapped, that is, the liquid injection port 142 and the notch 1311 are disposed approximately opposite to each other, so that the electrolyte injected from the liquid injection port 142 can directly permeate into the cell body 120 through the notch 1311, thereby improving the liquid injection efficiency. It is understood that, in this embodiment, the projection of the liquid injection port 142 and the projection of the opening 1311 refer to a graphic range surrounded by the projection of the side wall of the liquid injection port 142 in the height direction Z, and the projection of the opening 1311 refers to a range covered by the projection of the space included in the opening 1311 in the height direction Z.

Referring to fig. 3 and 4, the bracket 130 further includes a support portion 133, the support portion 133 being provided on one surface of the main body portion 131 near the top cover 140 in the height direction Z and extending toward the top cover 140, the support portion 133 abutting against the top cover 140. In this embodiment, the number of the supporting portions 133 is four, and the four supporting portions 133 are preferably uniformly distributed along the circumferential direction of the main body 131, and in particular, the four supporting portions 133 are distributed at four corners of the main body 131, which are close to one surface of the top cover 140, and the four supporting portions 133 cooperate to form a support for the top cover 140, so that a gap exists between the top cover 140 and the main body 131 and between the top cover 140 and the end face 122 of the cell body 120, and a space between the top cover 140 and the cell body 120 is increased, so that in the stage of injecting electrolyte in the production process, a buffer space is provided for the electrolyte to flow into the cell body 120, and the buffer space communicates with the liquid injection port 142 and the opening 1311, so that the electrolyte can quickly and fully infiltrate into the cell body 120. In addition, in the process of assembling the top cover 140 with the opening 111 of the housing 110, the top cover 140 presses down the main body portion 131 and the pressing portion 132 along the height direction Z through the supporting portion 133, so as to increase the pressing force of the pressing portion 132 on the side 121 of the battery cell body 120, ensure that the positive electrode sheet, the separator and the negative electrode sheet located in the thinned section 120b are tightly attached, and improve the cycle capacity retention rate of the unit battery 100.

In addition, the supporting portion 133 is provided with a through hole 1331 penetrating the supporting portion 133 and the main body portion 131 along the height direction Z, and the through hole 1331 is formed, so that the overall weight of the bracket 130 can be reduced, the weight of the single battery 100 can be further reduced, and the overall weight energy density of the battery pack can be further improved.

The application also provides a battery pack, which comprises a box body and a plurality of single batteries 100, wherein the single batteries 100 are stacked in the box body.

The above description has been made in detail on a single battery and a battery pack provided in the embodiments of the present application, and specific examples are applied herein to illustrate the principles and embodiments of the present application, where the above description of the embodiments is only for helping to understand the method and core ideas of the present application; meanwhile, those skilled in the art will have variations in the specific embodiments and application scope in light of the ideas of the present application, and the present description should not be construed as limiting the present application in view of the above.

Claims

1. A single cell comprising:

a housing (110) provided with an opening (111), the housing (110) having a width direction (Y) and a height direction (Z) orthogonal to each other;

a top cover (140) which is arranged on the opening (111);

characterized by further comprising:

the battery cell body (120) is arranged in the shell (110), and the battery cell body (120) is provided with two side surfaces (121) which are oppositely arranged along the width direction (Y);

the bracket (130) is arranged in the shell (110), the bracket (130) comprises a main body part (131) and an extrusion part (132), the battery cell body (120), the main body part (131) and the top cover (140) are overlapped along the height direction (Z), and the extrusion part (132) is arranged on one surface of the main body part (131) away from the top cover (140) and extends in a direction away from the main body part (131);

in the width direction (Y), an assembly gap is formed between one end of the side surface (121) close to the main body part (131) and the shell (110), and the extrusion part (132) is inserted into the assembly gap and is connected with the side surface (121) and the shell (110).

2. The unit cell according to claim 1, characterized in that the assembly gap has a first distance in the width direction (Y) that decreases from an end closer to the main body portion (131) to an end farther from the main body portion (131) in the height direction (Z).

3. The unit cell according to claim 1, wherein the pressing portion (132) has a thickness in the width direction (Y) that decreases in the height direction (Z) from a connecting end of the pressing portion (132) with the main body portion (131) toward a direction away from the main body portion (131).

4. The unit cell according to claim 1, wherein the pressing portion (132) includes a first pressing portion (1321) and a second pressing portion (1322), the first pressing portion (1321) and the second pressing portion (1322) are disposed at both ends of the main body portion (131) at intervals in the width direction (Y), and the cell body (120) is disposed between the first pressing portion (1321) and the second pressing portion (1322);

two assembly gaps are defined between the two side surfaces (121) and the shell (110), and the first extrusion part (1321) and the second extrusion part (1322) are respectively inserted into the two assembly gaps.

5. The single cell of claim 1, wherein the main body (131) is provided with at least one opening (1311), and the opening (1311) penetrates through the main body (131) along the height direction (Z);

the top cover (140) is provided with a liquid injection port (142) for injecting electrolyte, and the liquid injection port (142) is communicated with at least one notch (1311).

6. The unit cell according to claim 1, wherein the holder (130) further comprises a supporting portion (133), the supporting portion (133) being disposed on a surface of the main body portion (131) adjacent to the top cover (140) and extending toward the top cover (140), the supporting portion (133) being abutted against the top cover (140).

7. The unit cell according to claim 6, characterized in that the number of the supporting parts (133) is at least two, distributed along the circumferential direction of the main body part (131).

8. The unit cell according to claim 6, wherein the supporting portion (133) is provided with a through hole (1331) penetrating the supporting portion (133) and the main body portion (131) in the height direction (Z).

9. The single battery according to claim 1, further comprising a tab, wherein the battery cell body (120) has two end surfaces (122) disposed opposite to each other along the height direction (Z), and the tab is disposed on at least one of the end surfaces (122) in a protruding manner along the height direction (Z);

an opening (1312) is formed in the main body portion (131), and the tab is arranged through the opening (1312).

10. A battery pack comprising the single battery according to any one of claims 1 to 9.