Self-constrained battery shell

Abstract

The utility model relates to a self-constrained battery shell, which comprises two oppositely arranged side walls I and two support plates I, the two support plates I are respectively arranged on the inner sides of the two side walls I, and the two support plates I are respectively connected with the inner surfaces of the two side walls I through a plurality of reinforcing ribs I. The first supporting plates are connected to the inner sides of the two first side walls of the battery shell, the strength of the first side walls is improved through the first supporting plates and the first reinforcing ribs, it is guaranteed that the battery shell is pressed and does not deform when the battery cell expands, meanwhile, the high-strength first side walls can restrain expansion of the battery cell, the stability of the shell is guaranteed, and the service life of the battery shell is prolonged. The protective performance of the battery shell is improved, the shell expansion problem in the battery manufacturing process is reduced, the battery cycle performance is improved, and the battery internal resistance is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of power batteries, in particular to a battery housing with self-constraint. Background Art

[0002] The negative electrode of a lithium battery is mainly made by mixing carbon materials or non-carbon materials, binders, conductive agents and other additives, coated on both sides of a copper foil, and then processed through processes such as drying and rolling. During the charging and discharging process of the lithium battery, under the action of the electrode voltage, lithium ions in the positive electrode undergo "intercalation" and "deintercalation" electrochemical reactions, and the negative electrode, as a carrier, is responsible for storing and releasing lithium ions and enabling current to pass through the external circuit. Graphite, as the main current negative electrode material, has a theoretical capacity of 372 mAh / g, and currently reaches 340 - 360 mAh / g, which is basically close to the limit capacity of the material. The mass energy density of a lithium battery is mainly determined by the specific capacity per gram of the positive electrode, the specific capacity per gram of the negative electrode, and the potential difference between the positive and negative electrodes. Under the condition that the specific capacity of the positive electrode material is certain, increasing the specific capacity per gram of the negative electrode material becomes one of the options. The theoretical specific capacity of a silicon-based negative electrode material is as high as 4200 mAh / g, which is about 10 times that of a graphite negative electrode and is currently the lithium-ion battery negative electrode material with the highest known specific capacity.

[0003] However, when silicon is fully lithiated, the volume of silicon will expand by more than 300%, and such a huge volume change will bring a series of problems, such as: the electrode sheet is prone to powdering, the powder material is separated from the foil, the SEI film is repeatedly damaged and generated, consuming lithium ions, etc. Currently, through various powder particle treatment technologies, part of the expansion problem can be solved, but the commercial capacity of the silicon-carbon negative electrode is below 450 mAh / g, with a high initial efficiency, but the volume expansion still exceeds 100%, and it can only be applied to cylindrical batteries, and it will still cause hard expansion of the battery during the production of square aluminum shell batteries. Summary of the Utility Model

[0004] Based on this, the purpose of the utility model is to provide a battery housing with self-constraint, with internal reinforcing ribs added to constrain the expansion of the silicon-based negative electrode core and ensure that the housing does not deform, thereby improving the electrical performance of the battery.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A battery housing with self-constraint provided by the utility model, the battery housing includes two oppositely arranged side walls one, and the battery housing further includes two support plates one, the two support plates one are respectively arranged on the inner sides of the two side walls one, and both of the two support plates one are connected to the inner surfaces of the two side walls one through a plurality of reinforcing ribs one.

[0007] In the present utility model, a first support plate is connected to the inner side of each of the two side walls of the battery case. The strength of the first side wall is improved through the first support plate and the first reinforcing rib, so as to ensure that the battery case is not deformed under pressure when the battery cell expands. At the same time, the high-strength first side wall can also restrain the expansion of the battery cell, ensure the stability of the case, improve the protection performance of the battery case, reduce the problem of case expansion during the battery manufacturing process, so as to improve the battery cycle performance and reduce the battery internal resistance. Since the first support plate and the first side wall are connected by a plurality of first reinforcing ribs and are provided with a hollow between them, the battery has better heat conduction performance.

[0008] As a further improvement of the above solution of the present utility model, the first support plate has an arc-shaped structure. From one end of the length direction of the first support plate to the other end of the length direction of the first support plate, the distance between the first support plate and the first side wall gradually increases first and then gradually decreases, and both ends of the length direction of the first support plate are connected to the inner surface of the first side wall.

[0009] As a further improvement of the above solution of the present utility model, a plurality of first reinforcing ribs are arranged at intervals along the length direction of the first side wall. One side in the length direction of the first reinforcing rib is connected to the first side wall by welding, and the other side in the length direction thereof is integrally formed with the first support plate. Along the length direction of the first side wall, the heights of the plurality of first reinforcing ribs gradually increase first and then gradually decrease in sequence.

[0010] As a further improvement of the above solution of the present utility model, a plurality of first reinforcing ribs are arranged at intervals along the width direction of the first side wall. One side in the length direction of the first reinforcing rib is connected to the first side wall by welding, and the other side in the length direction thereof is integrally formed with the first support plate. Along the length direction of the first side wall, the heights of each of the first reinforcing ribs gradually increase first and then gradually decrease.

[0011] As a further improvement of the above solution of the present utility model, the battery case further includes two second side walls and at least two second support plates. The two second side walls are arranged opposite to each other and the second side walls are perpendicular to the first side walls. At least one second support plate is provided on each of the opposite sides of the two second side walls. The second support plate is connected to the inner surface of the corresponding second side wall by a plurality of second reinforcing ribs. By providing the second support plates on the inner sides of the two second side walls of the battery case, the strength of the second side walls is improved, and it is ensured that the battery case is not deformed under pressure when the battery cell expands in the length direction. At the same time, the high-strength second side walls can also restrain the expansion of the battery cell, ensure the stability of the case, improve the protection performance of the battery case. Since the second support plate and the second side wall are provided with a hollow between them, the battery has better heat conduction performance.

[0012] As a further improvement of the above solution of the present utility model, the second side wall includes two side plates. The two side plates are integrally connected to the two first side walls respectively on the sides away from each other. Steps are provided on each of the sides of the two side plates close to each other. The two steps are buckled with each other and the two side plates are welded at the two steps. One second support plate is connected to the inner side of each side plate.

[0013] As a further improvement of the above solution of the present utility model, the second support plate has an arc-shaped structure. From one end of the second support plate in the length direction to the other end of the second support plate in the length direction, the distance between the second support plate and the side plate first gradually increases and then gradually decreases, and both ends of the second support plate in the length direction are connected to the inner surface of the side plate.

[0014] As a further improvement of the above solution of the present utility model, a plurality of second reinforcing ribs are arranged at intervals along the length direction of the side plate. One side of the second reinforcing rib in the length direction is welded to the side plate, and the other side of the second reinforcing rib in the length direction is integrally formed with the second support plate. And along the length direction of the side plate, the heights of the plurality of second reinforcing ribs first gradually increase and then gradually decrease.

[0015] As a further improvement of the above solution of the present utility model, a plurality of second reinforcing ribs are arranged at intervals along the width direction of the side plate. One side of the second reinforcing rib in the length direction is welded to the side plate, and the other side of the second reinforcing rib in the length direction is integrally formed with the second support plate. And along the length direction of the side plate, the heights of each of the second reinforcing ribs first gradually increase and then gradually decrease.

[0016] As a further improvement of the above solution of the present utility model, the thickness of the first side wall and the second side wall is 0.5 - 1.0 mm, and the thickness of the first reinforcing rib and the second reinforcing rib is 0.3 - 0.5 mm.

[0017] Compared with the prior art, the present utility model has the following beneficial effects:

[0018] In the present utility model, the first support plates are connected to the inner sides of the two first side walls of the battery housing. The strength of the first side walls is improved through the first support plates and the first reinforcing ribs, so as to ensure that the battery housing is not deformed under pressure when the battery cells expand. At the same time, the high-strength first side walls can also restrain the expansion of the battery cells, ensure the stability of the housing, improve the protection performance of the battery housing, reduce the problem of housing expansion during the battery manufacturing process, so as to improve the battery cycle performance and reduce the battery internal resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural view of a battery housing with self-constraint proposed in Embodiment 1 of the present utility model;

[0020] Figure 2 It is an unfolded view of a battery housing with self-constraint proposed in Embodiment 1 of the present utility model;

[0021] Figure 3 It is a connection structure view of the first support plate and the first side wall in a battery housing with self-constraint proposed in Embodiment 1 of the present utility model;

[0022] Figure 4 It is a schematic view of the structure of the first side of the first support plate in a battery housing with self-constraint proposed in Embodiment 1 of the present utility model;

[0023] Figure 5 Partial structural schematic diagram of a side plate of side wall two in a battery case with self-constraint proposed in Embodiment 1 of the present utility model;

[0024] Figure 6 Partial structural schematic diagram of another side plate of side wall two in a battery case with self-constraint proposed in Embodiment 1 of the present utility model;

[0025] Figure 7 Structural schematic diagram of support plate two in a battery case with self-constraint proposed in Embodiment 1 of the present utility model;

[0026] Figure 8 It is Figure 7 Enlarged schematic diagram at A in

[0027] Figure 9 Folding schematic diagram of side wall one during the manufacture of a battery case with self-constraint proposed in Embodiment 1 of the present utility model;

[0028] Figure 10 Folding schematic diagram of a side plate during the manufacture of a battery case with self-constraint proposed in Embodiment 2 of the present utility model;

[0029] Figure 11 Structural schematic diagram of support plate two in a battery case with self-constraint proposed in Embodiment 2 of the present utility model.

[0030] Reference numerals: 1, side wall one; 2, support plate one; 201, reinforcing rib one; 3, side wall two; 301, side plate; 302, step; 4, support plate two; 401, reinforcing rib two; 5, bottom plate. Detailed implementation manners

[0031] To facilitate the understanding of the present utility model, the present utility model will be described more comprehensively below in conjunction with specific embodiments. However, the present utility model can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present utility model more thorough and comprehensive.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present utility model belongs. The terms used in the description of the present utility model herein are only for the purpose of describing specific embodiments and are not intended to limit the present utility model.

[0033] Embodiment 1

[0034] Refer to Figure 1 、 Figure 2, this embodiment proposes a battery case with self - restraint. The battery case in this embodiment is of a square structure, which includes two side plates 301 and two support plates 1. It may also include two side walls 3, four support plates 4 and a bottom plate 5.

[0035] The two side walls 1 are arranged parallel and opposite to each other in the thickness direction of the battery case. In this embodiment, both of the two side walls 1 are made of aluminum sheets, and the thickness of the aluminum sheets is 0.5 - 1.0 mm. The distance between the two side walls 1 is not specifically limited. In actual production, the distance between the two side walls 1 can be reasonably designed according to the thickness requirement of the battery cell.

[0036] The two support plates 1 are respectively arranged corresponding to the two side walls 1, and the two support plates 1 are respectively arranged inside the two side walls 1. Combining Figure 3 , Figure 4 , on the side of the support plate 1 facing the corresponding side wall 1, a plurality of first reinforcing ribs 201 are arranged, and the plurality of first reinforcing ribs 201 are all connected to the corresponding side wall 1. In this embodiment, the plurality of first reinforcing ribs 201 and the support plate 1 are integrally formed, and the plurality of first reinforcing ribs 201 and the side wall 1 are connected by welding. In this embodiment, the support plate 1 is of an arc - shaped structure, with the middle of the support plate 1 being high and the two sides being low. From one end of the length direction of the support plate 1 to the other end of the length direction of the support plate 1, the distance between the support plate 1 and the side wall 1 first gradually increases and then gradually decreases, and both ends of the length direction of the support plate 1 are connected to the inner surface of the side wall 1. The plurality of first reinforcing ribs 201 are arranged at intervals along the length direction of the side wall 1, and along the length direction of the side wall 1, the heights of the plurality of first reinforcing ribs 201 first gradually increase and then gradually decrease. In this embodiment, the height of the first reinforcing rib 201 is controlled within 0.3 - 0.5 mm. In this embodiment, the width and length of the support plate 1 are not specifically limited, and the number of the first reinforcing ribs 201 is also not specifically limited, and can be reasonably set according to the specific size of the battery case.

[0037] The two side walls 3 are arranged parallel and opposite to each other in the length direction of the battery case, and the two side walls 3 are both perpendicular to the side wall 1. In this embodiment, both of the two side walls 3 are made of aluminum sheets, and the thickness of the aluminum sheets is 0.5 - 1.0 mm. The distance between the two side walls 3 is not specifically limited. In actual production, the distance between the two side walls 3 can be reasonably designed according to the length requirement of the battery cell. In this embodiment, each side wall 3 includes two side plates 301. The two side plates 301 are integrally connected to the two side walls 1 respectively on the sides away from each other. Combining Figure 5 , Figure 6 , on the sides where the two side plates 301 are close to each other, steps 302 are arranged, the two steps 302 are buckled with each other, and the two side plates 301 are welded and connected at the two steps.

[0038] Four second support plates 4 are respectively arranged corresponding to the four side plates 301, and the four second support plates 4 are respectively arranged inside the four side plates 301. Combining Figure 7 , Figure 8 , a plurality of second reinforcing ribs 401 are arranged on one side of the second support plate 4 facing the corresponding side plate 301, and the plurality of second reinforcing ribs 401 are all connected to the corresponding first side wall 1. In this embodiment, the plurality of second reinforcing ribs 401 are integrally formed with the second support plate 4, and the plurality of second reinforcing ribs 401 and the side plate 301 are connected by welding. In this embodiment, the second support plate 4 has an arc-shaped structure, with the middle of the second support plate 4 being high and the two sides being low. From one end of the second support plate 4 in the length direction to the other end of the second support plate 4 in the length direction, the distance between the second support plate 4 and the side plate 301 gradually increases first and then gradually decreases, and both ends of the second support plate 4 in the length direction are connected to the inner surface of the first side wall 1. The plurality of second reinforcing ribs 401 are arranged at intervals along the width direction of the side plate 301, and along the length direction of the side plate 301, the height of each second reinforcing rib 401 gradually increases first and then gradually decreases. In this embodiment, the height of the second reinforcing rib 401 is controlled within 0.3 - 0.5 mm. In this embodiment, the width and length of the second support plate 4 are not specifically limited, and the number of the second reinforcing ribs 401 is also not specifically limited, and can be reasonably set according to the specific size of the battery housing.

[0039] The bottom plate 5 is arranged at the bottoms of the two first side walls 1 and the two second side walls 3. The two sides in the length direction of the bottom plate 5 are integrally connected to the bottoms of the two first side walls 1 respectively, and the two sides in the width direction of the bottom plate 5 are welded to the bottom plate 5 of the two second side walls 3 respectively. There is a certain gap between the first support plate 2, the second support plate 4 and the bottom plate 5, which can be used as a channel for the electrolyte to flow.

[0040] When manufacturing the self-constrained battery housing of this embodiment, it can be carried out according to the following method:

[0041] A. According to the design size of the battery, as shown in the figure, cut out a predetermined shape on an aluminum sheet with a thickness of 0.5 - 1.0 mm. At this time, the two sides in the length direction of the bottom plate 5 are respectively connected to one side of the two first side walls 1, and the side plates 301 are connected to both sides of the first side wall 1;

[0042] B. As shown in the figure, process a step 302 on the edge part of each side plate 301 away from the first side wall 1. The thickness of the step 302 is half of the thickness of the aluminum sheet, and the depth is 0.25 mm;

[0043] C. Weld the first reinforcing ribs 201 of the first support plate 2 to the first side wall 1 and weld the plurality of second reinforcing ribs 401 of the second support plate 4 to the side plate 301 by laser welding;

[0044] D. Combining Figure 9, the two side walls 1 are folded by the way of pre - folding, and when folding, it is necessary to be along the junction of the side wall 1 and the bottom plate 5. Then, the four side plates 301 are folded by the way of folding, and when folding, it is necessary to be along the junction of the side plate 301 and the side wall 1;

[0045] E. The steps of the two side plates 301 at the same end of the side wall 1 are buckled, and then the two side plates 301 are welded by laser welding to form the side wall 2 3;

[0046] F. Finally, the two side walls 2 3 are welded to both ends in the width direction of the bottom plate 5 by laser welding, and the battery housing is finally formed.

[0047] The battery housing of this embodiment is formed by folding an aluminum sheet. The aluminum sheet is convenient to form, and the formed structure has good integrity. The reinforcing ribs are not affected by pressure and are not prone to production defects.

[0048] Embodiment 2

[0049] This embodiment provides a battery housing with self - restraint. The battery housing of this embodiment is also a square structure. This embodiment adopts the same implementation method as Embodiment 1. The difference from Embodiment 1 is that: in this embodiment, in combination Figures 10 - 11 , a plurality of first reinforcing ribs 201 are arranged at intervals along the width direction of the side wall 1, and along the length direction of the side wall 1, the height of each first reinforcing rib 201 first gradually increases and then gradually decreases; a plurality of second reinforcing ribs 401 are arranged at intervals along the length direction of the side plate 301, and along the length direction of the side wall 1, the height of the plurality of second reinforcing ribs 401 first gradually increases and then gradually decreases in sequence. When manufacturing the battery housing of this embodiment, in step D, first, the four side plates 301 are folded by the way of folding, and when folding, it is necessary to be along the junction of the side plate 301 and the side wall 1. Then, the two side walls 1 are folded by the way of folding, and when folding, it is necessary to be along the junction of the side wall 1 and the bottom plate 5.

[0050] It should be noted that when a component is referred to as "installed on" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "set on" another component, it can be directly set on the other component or there may be an intermediate component at the same time. When a component is considered to be "fixed to" another component, it can be directly fixed on the other component or there may be an intermediate component at the same time.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this utility model belongs. The terms used in the specification of this utility model herein are for the purpose of describing specific embodiments only and are not intended to limit this utility model. The term "or / and" as used herein includes any and all combinations of one or more of the related listed items.

[0052] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0053] The above-described embodiments merely represent several implementation manners of this utility model. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of this utility model, several modifications and improvements can still be made, and these all belong to the protection scope of this utility model. Therefore, the protection scope of the utility model patent shall be subject to the appended claims.

Claims

1. A battery housing with self-constraint, the battery housing includes two oppositely arranged side walls one (1), characterized in that, The battery housing further includes two first support plates (2), and the two first support plates (2) are respectively arranged on the inner sides of the two first side walls (1), and the two first support plates (2) are respectively connected to the inner surfaces of the two first side walls (1) through a plurality of first reinforcing ribs (201).

2. The self-constrained battery housing according to claim 1, characterized in that, The first support plate (2) is in an arc structure. From one end of the first support plate (2) in the length direction to the other end of the first support plate (2) in the length direction, the distance between the first support plate (2) and the first side wall (1) gradually increases first and then gradually decreases, and both ends of the first support plate (2) in the length direction are connected to the inner surface of the first side wall (1).

3. The battery housing with self-constraint according to claim 2, wherein, The plurality of first reinforcing ribs (201) are arranged at intervals along the length direction of the first side wall (1). One side in the length direction of the first reinforcing rib (201) is connected to the first side wall (1) by welding, and the other side in the length direction thereof is integrally formed with the first support plate (2), and along the length direction of the first side wall (1), the heights of the plurality of first reinforcing ribs (201) gradually increase first and then gradually decrease in sequence.

4. The self-constrained battery housing according to claim 2, wherein The plurality of first reinforcing ribs (201) are arranged at intervals along the width direction of the first side wall (1). One side in the length direction of the first reinforcing rib (201) is connected to the first side wall (1) by welding, and the other side in the length direction thereof is integrally formed with the first support plate (2), and along the length direction of the first side wall (1), the heights of the respective first reinforcing ribs (201) gradually increase first and then gradually decrease.

5. The self-constrained battery housing according to claim 1, wherein The battery housing further includes two second side walls (3) and at least two second support plates (4). The two second side walls (3) are arranged oppositely and the second side walls (3) are perpendicular to the first side walls (1); at least one second support plate (4) is arranged on each of the opposite sides of the two second side walls (3), and the second support plate (4) is connected to the inner surface of the corresponding second side wall (3) through a plurality of second reinforcing ribs (401).

6. The battery housing with self-constraint according to claim 5, characterized in that, The second side wall (3) includes two side plates (301). The two side plates (301) are respectively integrally connected to the two first side walls (1) on the sides away from each other. Steps (302) are arranged on the sides of the two side plates (301) close to each other. The two steps (302) are buckled with each other and the two side plates (301) are welded and connected at the two steps (302), and one second support plate (4) is connected to the inner side of each side plate (301).

7. The battery housing with self-constraint according to claim 6, wherein, The second support plate (4) is in an arc structure. From one end of the second support plate (4) in the length direction to the other end of the second support plate (4) in the length direction, the distance between the second support plate (4) and the side plate (301) gradually increases first and then gradually decreases, and both ends of the second support plate (4) in the length direction are connected to the inner surface of the side plate (301).

8. The battery housing with self-constraint according to claim 7, characterized in that, The plurality of second reinforcing ribs (401) are arranged at intervals along the length direction of the side plate (301). One side in the length direction of the second reinforcing rib (401) is connected to the side plate (301) by welding, and the other side in the length direction thereof is integrally formed with the second support plate (4), and along the length direction of the side plate (301), the heights of the plurality of second reinforcing ribs (401) gradually increase first and then gradually decrease in sequence.

9. The battery housing with self-constraint according to claim 7, characterized in that, A plurality of second reinforcing ribs (401) are arranged at intervals along the width direction of the side plate (301). One side in the length direction of the second reinforcing rib (401) is welded to the side plate (301), and the other side in the length direction thereof is integrally formed with the second support plate (4). Along the length direction of the side plate (301), the height of each second reinforcing rib (401) first gradually increases and then gradually decreases.

10. The self-constrained battery housing according to claim 5, characterized in that, The thickness of the first side wall (1) and the second side wall (3) is 0.5 - 1.0 mm, and the thickness of the first reinforcing rib (201) and the second reinforcing rib (401) is 0.3 - 0.5 mm.

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