Battery cell and battery pack

Abstract

The utility model relates to battery technology field discloses electric core and battery package. Electric core includes: casing, pole group structure sets up in the inner chamber of casing, and pole group structure includes pole group and insulating film, and insulating film is wrapped in the at least part of pole group outer surface, bottom support plate sets up in the inner chamber of casing, and supports between pole group structure and the inner wall of casing, and the score of several interval settings is opened in bottom support plate, and the score penetrates bottom support plate along the thickness direction of bottom support plate. The score is the penetrating structure, and the score cuts open the partial area on bottom support plate but does not remove material, and the score can allow electrolyte to pass, guarantees that pole group can be infiltrated by electrolyte fully evenly, and the score size is smaller, can reduce the damage to bottom support plate structural strength, improves the structural strength of bottom support plate, also can block the material that falls on pole group to pass through, thereby reduces the possibility of insulation failure between pole group and casing, further improves the insulation performance, makes bottom support plate have better infiltrability and insulation performance.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to battery cells and battery packs. Background Technology

[0002] A battery cell consists of a housing, a cover assembly, and electrode assemblies, with the electrode assemblies placed within a sealed space formed by the housing and cover assembly. A base plate is also located inside the cell, positioned between the electrode assemblies and the housing, to support the electrode assemblies and provide insulation between them. However, in existing technologies, to improve the wettability of the electrolyte to the electrode assemblies, several through-holes for electrolyte passage are typically provided on the base plate. These through-holes can lead to insulation failure at these locations. Furthermore, powder particles falling from the electrode sheets can accumulate in the through-holes, causing short circuits between the electrode assemblies and the housing, further affecting the insulation effect of the base plate between the electrode assemblies and the housing, and ultimately impacting the normal operation of the battery cell assembly. Utility Model Content

[0003] In view of this, the present invention provides a battery cell and battery pack to solve the problem of poor insulation effect of the base plate.

[0004] In a first aspect, the present invention provides a battery cell, comprising: a housing; an electrode assembly structure disposed in the inner cavity of the housing, the electrode assembly structure comprising an electrode assembly and an insulating film, the insulating film covering at least a portion of the outer surface of the electrode assembly; and a base plate disposed in the inner cavity of the housing and supported between the electrode assembly structure and the inner wall of the housing, the base plate having a plurality of spaced grooves that penetrate the base plate along its thickness direction.

[0005] Beneficial effects: By creating grooves on the base plate, the grooves are penetrating structures that cut open a portion of the base plate without removing material. The grooves allow the electrolyte to pass through, ensuring that the electrode assembly is fully and evenly wetted by the electrolyte. Furthermore, since the grooves do not remove material from the base plate, their size is smaller than that of traditional circular through holes, which reduces damage to the structural strength of the base plate and improves its structural strength. It also prevents material falling from the electrode assembly from passing through, thereby reducing the possibility of insulation failure between the electrode assembly and the shell, further improving insulation performance, and giving the base plate better wettability and insulation performance.

[0006] In one alternative implementation, the notch is at least one of the following: straight line, cross shape, zigzag shape, and curve shape.

[0007] Beneficial effects: There are many options for the shape of the grooves, and the appropriate shape of the grooves can be selected according to the size of the base plate, which provides high design flexibility.

[0008] In one alternative embodiment, the base plate includes one or more rows of the grooves, each row of the grooves including a plurality of grooves spaced apart along the length of the base plate.

[0009] Beneficial effects: The number of rows of grooves can be reasonably selected according to the actual width of the base plate, thereby maximizing the wetting effect of the electrolyte while ensuring the structural strength and insulation performance of the base plate.

[0010] In one alternative embodiment, the base plate includes multiple rows of grooves, with multiple grooves in adjacent rows being aligned or staggered.

[0011] Beneficial effects: The alignment of multiple grooves in two adjacent rows can improve the wetting effect of the electrolyte on the electrode assembly by increasing the number of grooves, and also facilitates the processing and shaping of the grooves on the base plate; the staggered distribution of multiple grooves in two adjacent rows can improve the structural strength and insulation performance of the base plate.

[0012] In one optional embodiment, the insulating film includes a first film region disposed opposite to the base plate, the first film region having a tangent line that penetrates the first film region along its thickness direction.

[0013] Beneficial effects: By setting a tangent on the first membrane area of ​​the insulating film corresponding to the bottom plate, the tangent is a penetrating structure. The tangent cuts a small opening in the first membrane area but does not remove material, allowing the electrolyte to pass through. This further ensures that after passing through the grooves on the bottom plate, the electrolyte can further pass through the insulating film via the tangent and enter the electrode assembly, achieving full wetting of the electrode assembly. In addition, the tangent can block powder particles falling from the electrode assembly, avoiding the problem of poor insulation performance between the electrode assembly and the shell caused by forming circular through holes in the insulating film in the traditional way. In other words, the insulation between the electrode assembly and the shell is further improved.

[0014] In one alternative implementation, the tangent is misaligned with the notch.

[0015] Beneficial effects: It allows the electrolyte to pass through while further blocking the powder falling from the electrode assembly, thereby further improving the insulation performance between the electrode assembly and the housing.

[0016] In one optional embodiment, the distance between adjacent tangents and the notches along the length and / or width of the base plate is A, wherein the value of A ranges from 5 mm to A ≤ 30 mm.

[0017] Beneficial effects: It can ensure the insulation performance between the electrode assembly and the shell while ensuring the wetting effect of the electrolyte.

[0018] In one optional embodiment, the base plate is provided with a plurality of hot-melt points to heat-melt the base plate to the first film area, and the hot-melt points are distributed at intervals with the grooves.

[0019] Beneficial effects: By setting the base plate and the insulating film to be thermally fused together, a stable connection between the base plate and the insulating film can be ensured, and relative movement between the base plate and the insulating film can be avoided when the cell is subjected to external force, thereby improving the structural stability of the cell. Furthermore, by setting the thermal melting point and the groove to be staggered, the thermal melting point and the groove do not coincide, avoiding the thermal melting point from blocking the groove, thereby avoiding affecting the electrolyte from passing through the groove, thus ensuring the wetting effect of the electrolyte on the electrode assembly.

[0020] In one alternative embodiment, the distance between the hot melt point and the groove along the length and / or width direction of the base plate is B, wherein the value of B is in the range of 8 mm ≤ B ≤ 35 mm.

[0021] Beneficial effects: It can avoid the sealing marks during the hot melting process between the base plate and the insulating film, and ensure that there are a sufficient number of marks on the base plate, thereby ensuring the smooth flow of electrolyte and ensuring that the electrolyte can fully wet the electrode assembly.

[0022] Secondly, this utility model also provides a battery pack, including the aforementioned battery cell. Since the battery pack includes the battery cell and has the same effects as the battery cell, it will not be described in detail here. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of the first type of base plate according to an embodiment of the present utility model; Figure 2 This is a schematic diagram of the structure of the second type of base plate according to an embodiment of the present utility model; Figure 3 This is a schematic diagram of the structure of the third type of base plate according to an embodiment of the present utility model; Figure 4 This is a schematic diagram of the structure of the fourth type of base plate according to an embodiment of the present utility model; Figure 5 This is a schematic diagram showing the positional relationship between the pole assembly structure and the base plate when they are not assembled, according to an embodiment of the present invention. Figure 6for Figure 5 A schematic diagram showing the positional relationship of the electrode assembly, insulating film, and base plate before assembly. Figure 7 This is a schematic diagram showing the positional relationship between the base plate and the insulating film according to an embodiment of the present utility model; Figure 8 for Figure 7 A magnified view of part C in the diagram.

[0025] Explanation of reference numerals in the attached figures: 10. Base plate; 101. Score; 102. Hot melting point; 20. Insulating film; 201. First film area; 2011. Tangent; 202. Second film area; 203. Third film area; 204. Fourth film area; 30. Electrode group; 40. Cover plate assembly. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0027] The battery cell contains an electrolyte that needs to wet the electrode assembly. A base plate supports the bottom of the electrode assembly. A base plate without through-holes will obstruct the electrolyte's wetting effect on the bottom of the electrode assembly. While a base plate with through-holes can improve the electrolyte's wetting effect, these through-holes can cause insulation failure at those points. Furthermore, powder particles falling from the electrode sheets in the electrode assembly can accumulate in the through-holes, causing a short circuit between the electrode assembly and the casing, further affecting the base plate's insulation effect between the electrode assembly and the casing, and impacting the normal operation of the battery cell assembly. In other words, the base plate in the relevant technology cannot simultaneously achieve good wetting and insulation performance.

[0028] The following is combined with Figures 1 to 8 The following describes embodiments of the present invention.

[0029] According to an embodiment of the present invention, a battery cell is provided, comprising: a housing, an electrode assembly structure, and a base plate 10. The electrode assembly structure is disposed within the inner cavity of the housing, and includes electrode assemblies 30 and an insulating film 20, with the insulating film 20 covering at least a portion of the outer surface of the electrode assembly 30. The base plate 10 is disposed within the inner cavity of the housing and supported between the electrode assembly structure and the inner wall of the housing. The base plate 10 has a plurality of spaced grooves 101 that penetrate the base plate 10 along its thickness direction. The thickness direction refers to... Figures 5 to 6The direction of the "Z" indicated by the middle arrow.

[0030] It should be noted that the battery cell has X, Y and Z directions that intersect each other. Preferably, the X, Y and Z directions are perpendicular to each other, and the X, Y and Z directions are the X-axis, Y-axis and Z-axis in a rectangular coordinate system.

[0031] The battery cell of this embodiment has a slit 101 made on the base plate 10. The slit 101 is a penetrating structure. The slit 101 cuts open a part of the base plate 10 but does not remove material. The slit 101 allows the electrolyte to pass through, ensuring that the electrode assembly 30 can be fully and evenly wetted by the electrolyte. Since the slit 101 does not remove material from the base plate 10, the size of the slit 101 is smaller than that of the traditional circular through hole, which can reduce the damage to the structural strength of the base plate 10, improve the structural strength of the base plate 10, and also prevent material falling from the electrode assembly 30 from passing through, thereby reducing the possibility of insulation failure between the electrode assembly 30 and the shell, further improving the insulation performance, so that the base plate 10 has better wettability and insulation performance.

[0032] In one embodiment, the notch 101 is at least one of the following shapes: straight line, cross shape, zigzag shape, and curve shape. The notch 101 offers a wide range of shape options, allowing for selection of a suitable shape based on the dimensions of the base plate 10, thus providing high design flexibility. It should be noted that all notches 101 on the base plate 10 can be of the same shape or a combination of different shapes.

[0033] Optionally, the notch 101 can be in the shape of a straight line (e.g., Figure 4 As shown), cross-shaped (as shown) Figure 1 As shown), X-shaped (as shown) Figure 2 As shown), V-shaped (as shown) Figure 3 The shape of the notch 101 can be at least one of the following: Y-shaped, L-shaped, T-shaped, or S-shaped. Of course, the shape of the notch 101 is not limited to the above forms and can also be other reasonable shapes.

[0034] In one embodiment, the base plate 10 includes one or more rows of grooves 101, each row of grooves 101 including a plurality of grooves 101 spaced apart along the length direction of the base plate 10. The length direction refers to... Figures 1 to 8 The direction indicated by the middle arrow "X"; when the grooves 101 are in multiple rows, the multiple rows of grooves 101 are along the width direction of the base plate 10 (i.e., Figure 1 Only Figure 8The grooves 101 are spaced apart in the direction indicated by the middle arrow (Y). It should be noted that for a narrower base plate 10 (smaller dimension along the Y direction), only one row of grooves 101 may be provided; for a wider base plate 10 (larger dimension along the Y direction), two or more rows of grooves 101 may be provided. The number of rows of grooves 101 can be reasonably selected according to the actual width of the base plate 10, thereby maximizing the wetting effect of the electrolyte while ensuring the structural strength and insulation performance of the base plate 10.

[0035] In one embodiment, the base plate 10 includes multiple rows of grooves 101, with multiple grooves 101 aligned in adjacent rows. That is, adjacent rows of grooves 101 have an equal number of grooves 101, and multiple grooves 101 in the first row correspond one-to-one with multiple grooves 101 in the second row along the Y direction (e.g., ...). Figure 4 As shown, increasing the number of notches 101 can improve the wetting effect of the electrolyte on the electrode assembly 30, and also facilitate the processing and shaping of notches 101 on the base plate 10. It can be understood that, as an alternative implementation, multiple notches 101 in two adjacent rows of notches 101 can also be staggered, that is, the notches 101 in the first row and the notches 101 in the second row are not completely corresponding in the Y direction, but are misaligned to improve the structural strength and insulation performance of the base plate 10.

[0036] In one embodiment, the insulating film 20 includes a first film region 201 disposed opposite to the base plate 10. A tangent 2011 is formed on the first film region 201, penetrating the first film region 201 along its thickness direction. The thickness direction of the first film region 201 is the same as the thickness direction of the base plate 10. Figures 5 to 6 The direction indicated by the "Z" arrow. By setting a tangent line 2011 on the first membrane area 201 of the insulating film 20 corresponding to the bottom support plate 10, the tangent line 2011 is a penetrating structure. The tangent line 2011 cuts a small opening in the first membrane area 201 but does not remove material, allowing the electrolyte to pass through. This further ensures that after the electrolyte passes through the groove 101 on the bottom support plate 10, it can further pass through the insulating film 20 via the tangent line 2011 and then enter the electrode assembly 30, achieving full wetting of the electrode assembly 30. In addition, the tangent line 2011 can block powder particles falling from the electrode assembly 30, avoiding the problem of poor insulation performance between the electrode assembly 30 and the shell caused by the traditional circular through hole formation on the insulating film 20, that is, further improving the insulation between the electrode assembly 30 and the shell.

[0037] It should be noted that the battery cell also includes a cover plate assembly 40, which includes a cover plate body. The cover plate assembly 40 mates with the open end of the housing, and the cover plate body is welded to the housing. The cover plate body integrates components such as electrode posts. The cover plate assembly 40 is located at one end of the electrode group 30 along the Z direction, and the electrode posts in the cover plate assembly 40 are welded to the electrode tabs of the electrode group 30. The end of the electrode group 30 away from the cover plate assembly 40 along the Z direction is the bottom surface of the electrode group. The first film region 201 of the insulating film 20 covers the bottom surface of the electrode group, and the bottom support plate 10 is located on the side of the first film region 201 along the Z direction away from the electrode group 30. The insulating film 20 wraps around the bottom surface (and four sides) of the electrode group 30, which can improve the insulation between the electrode group 30 and the housing.

[0038] Optionally, there may be multiple tangents 2011, which are distributed at intervals along the X direction. The first membrane region 201 may have one row of tangents or multiple rows of tangents, which are distributed at intervals along the Y direction.

[0039] In one embodiment, the four sides of the electrode assembly 30 include two large surfaces arranged opposite each other along the Y direction and two narrow surfaces arranged opposite each other along the X direction. The large surfaces of the electrode assembly 30 refer to the two sides with the larger areas, and the narrow surfaces refer to the other two sides with smaller areas. The insulating film 20 also includes two second film regions 202. Along the width direction (Y direction) of the first film region 201, one second film region 202 is provided on each side of the first film region 201. Each second film region 202 covers one large surface of the electrode assembly 30. The length direction (X direction) of each second film region 202... A third membrane region 203 is provided on each side of the first membrane region 201. After the second membrane region 202 covers the large surface of the electrode group, the third membrane region 203 bends towards the narrow surface of the electrode group and covers the narrow surface. The insulating film 20 also includes a fourth membrane region 204. There are two fourth membrane regions 204. The two fourth membrane regions 204 are respectively provided on both sides of the first membrane region 201 along the X direction. The fourth membrane regions 204 bend towards the Z direction to cover part of the narrow surface of the electrode group. A triangular notch is provided between the fourth membrane region 204 and the third membrane region 203. This facilitates the bending of each membrane region and ensures the tightness of the wrapping of the electrode group 30, thereby improving the insulation performance.

[0040] In one embodiment, the tangent 2011 and the notch 101 are misaligned, meaning that the orthographic projection of the tangent 2011 along the Z direction on the base plate 10 does not coincide with the notch 101. By misaligning the tangent 2011 on the insulating film 20 and the notch 101 on the base plate 10, direct penetration between the tangent 2011 and the notch 101 can be avoided. The electrolyte reaches the electrode assembly 30 through the notch 101, the gap between the base plate 10 and the insulating film 20, and the tangent 2011. This results in a bend in the channel formed by the notch 101 and the tangent 2011, allowing the electrolyte to pass through while further preventing powder falling from the electrode assembly from passing through, thereby further improving the insulation performance between the electrode assembly 30 and the housing.

[0041] In one embodiment, further combination Figures 7 to 8 As shown, along the length and / or width direction of the base plate 10, the distance between adjacent tangents 2011 and notches 101 is A, where the value of A ranges from 5 mm to 30 mm. If A is less than 5 mm, the tangent 2011 is too close to the notch 101, and powder falling from the electrode assembly 30 may still enter the through channel formed by the tangent 2011 and the notch 101, blocking the tangent 2011 or the notch 101, or even contacting the housing, causing a decrease in the insulation performance between the housing and the electrode assembly 30. If A is greater than 30 mm, the distance between the tangent 2011 and the notch 101 is too far, affecting the number of tangents 2011 and notches 101, thereby affecting the wetting effect of the electrolyte. Therefore, by limiting the distance A between adjacent tangents 2011 and notches 101 to a range of 5 mm to 30 mm, the insulation performance between the electrode assembly and the housing can be guaranteed while ensuring the wetting effect of the electrolyte.

[0042] It should be noted that, because the base plate 10 covers at least a portion of the first film region 201 of the insulating film 20, the tangent line 2011 is obscured. Figures 7 to 8 The tangent line 2011 is represented by a dashed line, but in reality, the tangent line 2011 is a straight line segment. Figures 7 to 8 The diagram shows a case where the insulating film 20 has two rows of tangents and the base plate 10 has a row of grooves 101. In this case, the orthographic projection of the tangents 2011 on the base plate 10 along the Z direction and the grooves 101 are spaced apart along the Y direction. The distance between the tangents 2011 and the grooves 101 along the Y direction is A. Other cases are similar and will not be described in detail here.

[0043] In one embodiment, the base plate 10 is provided with a plurality of hot-melt points 102 to thermally fuse the base plate 10 with the first membrane region 201. The hot-melt points 102 and the grooves 101 are distributed at intervals. By setting the base plate 10 and the insulating film 20 to be thermally fused together, a stable connection between the base plate 10 and the insulating film 20 can be ensured, and relative movement between the base plate 10 and the insulating film 20 can be avoided when the battery cell is subjected to external force, thereby improving the structural stability of the battery cell. Furthermore, by setting the hot-melt points 102 and the grooves 101 to be staggered, the hot-melt points 102 and the grooves 101 do not coincide, preventing the hot-melt points 102 from blocking the grooves 101, thereby avoiding affecting the electrolyte from passing through the grooves 101, and thus ensuring the wetting effect of the electrolyte on the electrode assembly 30.

[0044] It should be noted that during the cell assembly process, the base plate 10 is first heat-fused to the insulating film 20, then the electrode assembly is placed on the side of the insulating film 20 away from the base plate 10, and then the insulating film 20 is wrapped around the electrode assembly 30.

[0045] In one embodiment, the distance between the hot melt point 102 and the notch 101 along the length and / or width direction of the base plate 10 is B, where the value of B ranges from 8 mm to 35 mm. If B is less than 8 mm, the distance between the hot melt point 102 and the notch 101 is too small, and during the hot-melt connection between the base plate 10 and the insulating film 20, the notch 101 may still be partially blocked by the hot melt material, affecting the flow of electrolyte. If B is greater than 35 mm, the distance between the hot melt point 102 and the notch 101 is too large, and the number of notches 101 is too small, which will also affect the flow of electrolyte and cannot guarantee that the electrolyte fully wets the electrode assembly 30. Therefore, by limiting B to a value between 8 mm and 35 mm, it is possible to avoid blocking the grooves 101 during the hot melting process between the base plate 10 and the insulating film 20, and to ensure that there are a sufficient number of grooves 101 on the base plate 10, thereby ensuring the smooth flow of electrolyte and ensuring that the electrolyte can fully wet the electrode assembly 30.

[0046] In one embodiment, both the base plate 10 and the insulating film 20 are made of insulating materials to ensure insulation performance. The insulating material of the base plate 10 can be plastic, rubber, etc., which not only have good insulation performance but are also easy to process and mold, thus meeting the structural requirements of the base plate 10.

[0047] According to an embodiment of the present invention, another aspect provides a battery pack, including the aforementioned battery cells. The battery pack also includes a housing, in which the battery cells are placed. Optionally, the number of battery cells is multiple.

[0048] Optionally, the battery cell is a lithium-ion battery cell.

[0049] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that, include: case; An electrode assembly structure is disposed in the inner cavity of the housing. The electrode assembly structure includes an electrode assembly and an insulating film, wherein the insulating film covers at least a portion of the outer surface of the electrode assembly. A base plate is disposed in the inner cavity of the housing and supported between the pole assembly structure and the inner wall of the housing. The base plate has several spaced grooves that penetrate the base plate along its thickness direction.

2. The battery cell according to claim 1, characterized in that, The engraving is in the form of at least one of the following: straight line, cross, zigzag, or curved.

3. The battery cell according to claim 1, characterized in that, The base plate includes one or more rows of grooves, and each row of grooves includes a plurality of grooves spaced apart along the length of the base plate.

4. The battery cell according to claim 3, characterized in that, The base plate includes multiple rows of grooves, with multiple grooves in adjacent rows being aligned or staggered.

5. The battery cell according to any one of claims 1 to 4, characterized in that, The insulating film includes a first film area disposed opposite to the base plate, and a tangent is formed on the first film area, the tangent penetrating the first film area along the thickness direction of the first film area.

6. The battery cell according to claim 5, characterized in that, The tangent is misaligned with the notch.

7. The battery cell according to claim 6, characterized in that, Along the length and / or width of the base plate, the distance between adjacent tangents and the notches is A, where the value of A ranges from 5 mm to 30 mm.

8. The battery cell according to claim 5, characterized in that, The base plate is provided with a plurality of hot-melt points so that the base plate is hot-melt connected to the first film area, and the hot-melt points are distributed at intervals with the grooves.

9. The battery cell according to claim 8, characterized in that, Along the length and / or width of the base plate, the distance between the hot melt point and the groove is B, wherein the value of B is in the range of 8 mm ≤ B ≤ 35 mm.

10. A battery pack, characterized in that, include: The battery cell according to any one of claims 1 to 9.

Images