Cell cases and the cells containing them

Abstract

The present invention provides a cell case and a cell containing the same that can at least improve the energy density of the manufactured cell. [Solution] The cell case includes a case body having through holes, made of steel, with a thickness direction in the first direction, and including a first side and a second side facing each other in the first direction; a positive electrode terminal penetrating through the through holes; an upper insulating member installed between the positive electrode terminal and the case body to insulate the positive electrode terminal from the case body; and a first terminal layer and a second terminal layer installed along the first direction, the first and second terminal layers being electrically connected, the second terminal layer being electrically connected to the first side, the second terminal layer being made of steel, and a negative electrode terminal being made of a different material from the second terminal layer. By using steel instead of aluminum alloy as the material for the case body, the energy density of the manufactured cell can be improved.

Description

Technical Field

[0001] The present invention relates to a cell case and a cell including the same.

Background Art

[0002] A rectangular cell generally includes at least a cell case and an electrode assembly installed in the cell case. After the positive and negative electrodes are led out by the electrode assembly, they are connected to positive and negative electrode terminals installed on the surface of the cell case. The cell case often uses an aluminum alloy.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The technical problem to be solved by the present invention is to provide a cell case and a cell including the same in order to overcome the defects that the energy density of the cell of the conventional rectangular battery is low and the production and assembly costs are high.

Means for Solving the Problems

[0004] The present invention solves the above-mentioned technical problems by the following technical solutions.

[0005] The cell case has a through hole installed, the material is steel, the thickness direction is the first direction, in the first direction, it includes a case body including a first side surface and a second side surface facing each other, a positive electrode terminal penetrating through the through hole, an upper insulating member installed between the positive electrode terminal and the case body for insulating the positive electrode terminal and the case body, and includes a first terminal layer and a second terminal layer installed along the first direction, the first terminal layer and the second terminal layer are electrically connected, the second terminal layer is electrically connected to the first side surface, the material of the second terminal layer is steel, and a negative electrode terminal whose material of the first terminal layer is different from that of the second terminal layer.

[0006] By using steel instead of aluminum alloy as the material for the main body of the cell case, structural strength can be ensured while keeping the thickness thin. This increases the space utilization rate within the cell case and improves the energy density of the manufactured cells.

[0007] The negative terminal of the case comprises two parts: a first terminal layer and a second terminal layer. The material of the second terminal layer is steel and is electrically connected to the first side surface of the case body. The material of the first terminal layer differs from that of the second terminal layer and is used for connecting to external electrical connection components. The negative electrode of the electrode assembly of the cell housed within the case body is drawn outward through the second side surface of the case body, the second terminal layer of the negative electrode terminal, and the first terminal layer. This structural installation scheme reduces the number of parts required for the cell case, simplifies the structure, and lowers production and assembly costs.

[0008] At the same time, the case body, being made of steel, has a negative charge, which prevents rust from forming on the case body.

[0009] Preferably, the first side surface has a recess formed to be recessed toward the second side surface, and at least a portion of the second terminal layer is housed in the recess.

[0010] By providing a recess on the surface of the case body electrically connected to the second terminal layer, which can partially accommodate the second terminal layer, the recessed structure of the recess can be used to position the case body relative to the second terminal layer, and the connection strength between the negative electrode terminals including the second terminal layer and the case body can be improved by enclosing the second terminal layer. On the other hand, the space occupied by the negative electrode terminals including the second terminal layer on the first side surface of the case body can be reduced, and the space utilization rate of the cell can be further increased.

[0011] Preferably, the depth of the recess is at least half the thickness of the case body.

[0012] By making the depth of the recess at least half the thickness of the case body, it is ensured that the recess has sufficient depth to accommodate and position the second terminal layer, thereby further improving the positioning accuracy and connection strength of the second terminal layer. Furthermore, since the case body is manufactured using steel, it has relatively high structural strength, and even if a relatively deep recess is machined on the surface of the case body, it does not affect the dimensional accuracy and surface flatness of the case body.

[0013] Preferably, the depth of the recess is D, where 0.8 mm ≤ D ≤ 2 mm.

[0014] By making the recess depth of the concave portion 0.8 mm or more, it is possible to avoid situations where the penetration depth or welding strength is insufficient when connecting the second terminal layer of the negative electrode column and the case body using welding methods such as laser welding, due to the recess being too shallow. At the same time, by making the recess depth 2 mm or less, it is possible to avoid the weakening of the strength of the rounded connection portion formed by the tensile deformation of the material between the concave and non-concave parts due to the recess being too deep, thereby improving processability and manufacturability.

[0015] Preferably, the second side surface has a protrusion corresponding to the position of the recess.

[0016] By placing a protrusion at a position corresponding to a recess on the second side of the case body, the difficulty of processing can be reduced. In other words, the recess can be processed on the outside of the case body while the protrusion can be formed on the opposite surface of the case body at the same time. Furthermore, a surface that protrudes further from other surfaces of the case body is also advantageous for connecting the negative electrode tab.

[0017] Preferably, both the positive terminal and the negative terminal are installed on the first side surface of the case body, and on the second side surface, the protrusion and the positive terminal are at the same height.

[0018] By installing a structure in which the protrusion and the positive terminal are at the same height, it is possible to maintain a balance between the positive tab for connecting the positive terminal of the electrode assembly and the negative tab for connecting the negative terminal. This avoids situations where the connection becomes unstable due to one end being pulled, and at the same time, it reduces the difficulty of connection.

[0019] Preferably, there is a gap between the inner circumferential surface of the recess and the outer circumferential surface of the second terminal layer, and the dimension of the gap is M, where 0.1 mm ≤ M ≤ 0.2 mm.

[0020] By creating a gap between the inner surface of the recess and the outer surface of the second terminal layer, it becomes easier to install the negative terminal inside the recess. The gap should be kept to 0.2 mm or less to avoid the gap being too large and affecting the positioning of the second terminal layer in the recess. At the same time, the gap should be kept to 0.1 mm or more to avoid the gap being too small and affecting the pre-installation of the second terminal layer in the recess.

[0021] Preferably, on the first side surface, the surface of the second terminal layer and the surface of the case body are coplanar, and / or, on the first side surface, the surface of the first terminal layer protrudes from the surface of the case body.

[0022] By making the outer surface of the second terminal layer and the first side surface of the case body the same plane in the first direction, mounting and positioning during the welding process becomes easier. At the same time, by making the outer surface of the first terminal layer protrude from the surface of the first side surface of the case body, welding the outer surface of the first terminal layer to external electrical connection components becomes easier.

[0023] Preferably, along the first direction, the projection of the first terminal layer on the surface of the second terminal layer is located within the range of the second terminal layer.

[0024] By arranging the projection of the first terminal layer on the surface of the second terminal layer within the range of the second terminal layer, laser penetration welding can be performed on the portion of the surface of the second terminal layer that is not covered by the first terminal layer, and the second terminal layer and the case body can be welded and connected by the method of laser penetration welding.

[0025] Preferably, along the first direction, the region where the projection of the second terminal layer is not covered by the projection of the first terminal layer is an annular region provided along the edge of the projection of the second terminal layer.

[0026] The region on the second terminal layer that is not covered by the first terminal layer is annular, and by performing laser penetration welding of the second terminal layer through the annular region, the welding strength between the second terminal layer and the case body can be increased.

[0027] Preferably, the minimum width dimension of the annular region is Nmin, and Nmin ≥ 0.4 mm. And / or, the maximum width dimension of the annular region is Nmax, and Nmax ≤ 0.8 mm.

[0028] By setting the minimum width dimension Nmin of the annular region to be 0.4 mm or more, it is avoided that the width dimension of the annular region is too small to provide sufficient space for performing laser penetration welding. At the same time, by setting the maximum width dimension Nmax of the annular region to be 0.8 mm or less, it is avoided that the width dimension of the annular region is too large and the area dimension of the first terminal layer becomes too small, which affects the welding between external electrical connection components.

[0029] Preferably, the case further includes an annular sealing member, and the annular sealing member is fixed between the second terminal layer and the first side surface of the case body.

[0030] When the negative electrode tab of the electrode assembly is welded to the second side surface of the case body, the case body may melt and penetrate through to the first and second sides, causing the electrolyte on the second side surface to leak to the first side surface. To address this problem, an annular sealing member is installed between the second terminal layer and the first side surface of the case body, sealing the first side surface region surrounded by the annular sealing member. When the negative electrode tab of the electrode assembly and the case body are welded within the region surrounded by the annular sealing member, even if the case body melts during the welding process, the electrolyte will remain within the area surrounded by the annular sealing member after leaking to the first side surface of the case body, and will not leak further outwards.

[0031] Preferably, the welding area between the second terminal layer and the case body is located outside the annular sealing member.

[0032] The statement that the welding area between the second terminal layer and the case body is located outside the annular sealing member means that the projection of the welding area between the second terminal layer and the case body on the surface of the case body is located within the range sealed by the annular sealing member.

[0033] To explain in more detail, when the second terminal layer of the negative electrode terminal is welded to the first side surface of the case body, there is a possibility that the second terminal layer may melt and fall off, causing the electrolyte on the first side surface of the case body to leak out further through the melted second terminal layer. By positioning the welded area between the second terminal layer and the case body outside the annular sealing member, further leakage of the electrolyte within the area surrounded by the annular sealing member is prevented.

[0034] Preferably, the surface of the second terminal layer facing the first side surface and / or the first side surface further has a seal groove for accommodating the annular seal member.

[0035] By providing a sealing groove on the surface of the second terminal layer or the first side surface of the case body to accommodate the annular sealing member, and pre-positioning the annular sealing member before connecting the second terminal layer and the case body, it is possible to avoid displacement of the annular sealing member that would affect the sealing effect.

[0036] Preferably, in a second direction perpendicular to the first direction, one of the upper insulating member and the case body has a positioning portion that protrudes outward, and the other has a housing portion that fits with the positioning portion.

[0037] The case body is made of steel and is thin, making it impossible to create a deep recess on the surface of the case body to accommodate the upper insulating member and positive terminal and prevent rotation. Therefore, the rotation prevention capability of the upper insulating member relative to the case body is improved by providing an additional contact area by installing a positioning portion that extends in a second direction between the upper insulating member and the case body and fitting it with the housing portion.

[0038] Preferably, the case body includes an upper cover and a side case, the upper cover being electrically connected to the opening of the side case, and the upper cover and side case surrounding and forming a housing space.

[0039] The case body forms a housing space by combining the top cover and side cases and is used to house the electrode assembly of the cell. The positive and negative terminals of the electrode assembly housed in the case body can be brought out by placing the positive and negative terminals on the top cover or side cases according to the actual positional requirements.

[0040] Preferably, the material of the case body and the second terminal layer is 304 stainless steel. And / or, in the first direction, the shape of the negative terminal is rectangular, and rounded corners are provided on the four corners of the negative terminal. And / or, on the first side, the height of the positive terminal and the first terminal layer are the same. And / or, the thickness of the second terminal layer is T1, where 0.6 mm ≤ T1 ≤ 1 mm. And / or, the thickness of the first terminal layer is T2, where 0.6 mm ≤ T2 ≤ 1 mm. And / or, the thickness of the case body is T3, where 0.8 mm ≤ T3 ≤ 1.2 mm.

[0041] Specifically, by using 304 stainless steel to manufacture the case body and the second terminal layer, relatively good structural strength can be obtained, and corrosion resistance can be further improved.

[0042] By shaping the negative terminal in the first direction into a rectangle, it has superior anti-rotation capabilities. By rounding the four corners of the negative terminal, it is possible to avoid sharp corners damaging other components.

[0043] By making the thickness of the second terminal layer 0.6 mm or more, the problem of insufficient strength and increased difficulty in connecting to other components due to insufficient thickness is avoided. At the same time, by making the thickness of the second terminal layer 1 mm or less, the maximum weight reduction and cost reduction are achieved while meeting the strength and connection requirements with other components.

[0044] By making the thickness of the first terminal layer 0.6 mm or more, the problem of insufficient strength and increased difficulty in connecting to other components due to insufficient thickness is avoided. At the same time, by making the thickness of the first terminal layer 1 mm or less, the maximum weight reduction and cost reduction are achieved while meeting the strength and connection requirements with other components.

[0045] By making the case body thickness 0.8mm or more, we avoid the impact on strength caused by being too thin. At the same time, by making the case body thickness 1.2mm or less, we achieve maximum weight reduction and cost reduction while still meeting the required strength.

[0046] The cells include the cases of the cells described above. [Effects of the Invention]

[0047] The positive improvements of this invention are as follows:

[0048] (1) By using steel instead of aluminum alloy as the material for the case body, structural strength can be ensured while keeping the thickness thin, thereby increasing the space utilization rate within the cell case and improving the energy density of the manufactured cells.

[0049] (2) The negative electrode terminal of the case includes two parts, a first terminal layer and a second terminal layer, and by drawing the negative electrode of the electrode assembly outward through the case body, the second terminal layer and the first terminal layer of the negative electrode terminal, the number of parts required for the cell case can be reduced, simplifying the structure and lowering production and assembly costs.

[0050] (3) The case body has a negative charge, which prevents rust from forming on the case body. [Brief explanation of the drawing]

[0051] [Figure 1] This is a schematic diagram of the cell structure of Embodiment 1 of the present invention. [Figure 2] This is a schematic diagram of the exploded structure of a cell according to Example 1 of the present invention. [Figure 3] This is a schematic diagram of the structure of the upper cover of Embodiment 1 of the present invention. [Figure 4] This is a schematic diagram of the exploded structure of the upper cover portion of the case according to Embodiment 1 of the present invention. [Figure 5] This is a schematic diagram of the upper structure of the upper cover portion of the case according to Embodiment 1 of the present invention. [Figure 6] This is a cross-sectional view of the CC portion in Figure 5. [Figure 7a] This is a cross-sectional view (1) of section D in Figure 6. [Figure 7b] This is a cross-sectional view (2) of section D in Figure 6. [Figure 8] This is a schematic diagram of the exploded structure of the negative terminal and upper cover of Embodiment 1 of the present invention. [Figure 9] This is a schematic diagram of the structure of the upper cover portion of the case according to Embodiment 1 of the present invention. [Figure 10]This is a schematic diagram of the layout of the welded sealing area on the recessed surface of the upper cover in Embodiment 1 of the present invention. [Figure 11] This is a schematic diagram of the structure of one side of the cell in Example 2 of the present invention. [Figure 12] This is a schematic diagram of the other side of the cell in Embodiment 2 of the present invention. [Modes for carrying out the invention]

[0052] The present invention will be explained more clearly and completely below, with reference to preferred embodiments and in conjunction with the accompanying drawings.

[0053] Example 1

[0054] As shown in Figures 1 and 2, the present invention provides a case 10 for use in a cell 100. The case 10 includes an upper cover 1 and a side case 2, the side case 2 being open at one end to form an opening 21 and closed at the other end. The upper cover 1 closes the opening 21 of the side case 2 to form a housing space for housing the electrode assembly 20 of the cell 100. Both the positive electrode terminal 3 and the negative electrode terminal 4 are mounted on the upper cover 1 and draw out the positive and negative electrodes of the electrode assembly 20 (i.e., in this embodiment, the upper cover 1 is the case body of the case 10). An injection hole 15 is located between the positive electrode terminal 3 and the negative electrode terminal 4. An explosion-proof port is located at the bottom of the side case 2 (not shown).

[0055] The specific structure of cell 100 is described below. As shown in Figure 2, cell 100 includes the case 10, electrode assembly 20, and insulating sheet 30 described above. The insulating sheet 30 wraps around the outside of the electrode assembly 20 and is installed together with the electrode assembly 20 in the housing space of case 10. The positive electrode tab 201 and negative electrode tab 202 of the electrode assembly 20 are led out by the positive electrode terminal 3 and negative electrode terminal 4 located on the case body of case 10, respectively, and connected to the electrical connection components on the outside of cell 100 via the positive electrode terminal 3 and negative electrode terminal 4 to discharge power.

[0056] Specifically, as shown in Figure 3, in this embodiment, a through hole 11 is provided on the upper cover 1, the material of the upper cover 1 is steel, and the thickness direction of the upper cover 1 is the first direction A. In the first direction A, the upper cover 1 includes opposing first side a and second side b. The side of the upper cover 1 away from the electrode assembly 20 is the first side a, and the side closer to the electrode assembly 20 is the second side b. By using steel instead of aluminum alloy as the material for the upper cover 1 of the cell 100, structural strength can be ensured while keeping the thickness thin. This increases the space utilization rate within the case 10 of the cell 100 composed of the upper cover 1, thereby improving the energy density of the manufactured cell 100. At the same time, in this embodiment, by also using steel for the material of the side case 2 connected to the upper cover 1, welding of the upper cover 1 and the side case 2 becomes easier. At the same time, by also using steel for the side case 2, structural strength can be ensured while keeping the thickness similarly thin, thereby increasing the space utilization rate within case 10.

[0057] As shown in Figure 4, the positive terminal 3 penetrates through the through hole 11 of the upper cover 1. The upper insulating member 5 is installed between the positive terminal 3 and the first side surface a of the upper cover 1 to insulate the positive terminal 3 from the case body. The negative terminal 4 includes a first terminal layer 41 and a second terminal layer 42 installed along the first direction A. The first terminal layer 41 and the second terminal layer 42 are electrically connected, and the second terminal layer 42 is electrically connected to the first side surface a. The material of the second terminal layer 42 is steel, and the material of the first terminal layer 41 is different from the material of the second terminal layer 42.

[0058] As shown in Figures 7a and 8, the negative electrode terminal 4 of the case 10 includes two parts: a first terminal layer 41 and a second terminal layer 42. The second terminal layer 42 is made of steel and is electrically connected to the first side a of the upper cover 1, while the first terminal layer 41 is made of a different material than the second terminal layer 42 and is used for connecting to external electrical connection components. The negative electrode tab 202 of the electrode assembly 20 of the cell 100 housed within the upper cover 1 is drawn outward through the second side b of the upper cover 1, the second terminal layer 42 and the first terminal layer 41 of the negative electrode terminal 4. This structural installation scheme reduces the number of parts required for the case 10 of the cell 100, simplifying the structure and reducing production and assembly costs. At the same time, the upper cover 1, being made of steel, has a negative charge, which prevents rust from forming on the case body.

[0059] Specifically, in this embodiment, the material of the first terminal layer 41 is an aluminum alloy, so it is compatible with aluminum external electrical connection components and is securely connected to the external electrical connection components by welding. In other embodiments, the material of the first terminal layer 41 can be adjusted in accordance with the material of the external electrical connection components. Also, in this embodiment, the first terminal layer 41 and the second terminal layer 42 are connected by a metal composite method, but naturally, in other embodiments, the first terminal layer 41 and the second terminal layer 42 may be connected by other methods existing in the prior art, such as riveting or welding. Furthermore, in this embodiment, the material of both the upper cover 1 and the second terminal layer 42 of the negative electrode terminal 4 is 304 stainless steel, so relatively good structural strength can be obtained, corrosion resistance can be further enhanced and the durability of use can be greatly improved.

[0060] As shown in Figures 3, 6, and 7a, the first side surface a of the upper cover 1 has a recess 12 formed to curve toward the second side surface b, and the second terminal layer 42 is housed within the recess 12. By providing a recess 12 capable of accommodating the second terminal layer 42 on the surface of the upper cover 1, which is electrically connected to the second terminal layer 42, positioning can be performed relative to the second terminal layer 42 by utilizing the recessed structure of the recess 12, and the connection strength between the negative electrode terminal 4, including the second terminal layer 42, and the upper cover 1 can be improved by enclosing the second terminal layer 42. On the other hand, the space occupied by the negative electrode terminal 4, including the second terminal layer 42, on the first side surface a of the upper cover 1 can be reduced, further increasing the space utilization rate of the cell 100. Specifically, in this embodiment, since the recess 12 can accommodate the entire second terminal layer 42 of the negative electrode terminal 4, the surface of the second terminal layer 42 and the surface of the upper cover 1 can be made coplanar on the first side surface a of the upper cover 1, which is convenient for mounting and positioning during the welding process. In other embodiments, the depth of the recess 12 may accommodate only a portion of the second terminal layer 42, so that the surface of the second terminal layer 42 protrudes relatively from the first side surface a. Also in this embodiment, since the surface of the first terminal layer 41 protrudes from the surface of the upper cover 1, it is convenient for welding the outer surface of the first terminal layer 41 to external electrical connection components.

[0061] Furthermore, as shown in Figure 7a, the upper cover 1 has a protrusion 13 on its second side b, corresponding to the position of the recess 12 on its first side a. That is, the recess 12 is machined on the outside (first side a) of the upper cover 1, and at the same time, the protrusion 13 is formed on the opposite surface of the upper cover 1 to make an electrical connection with the negative electrode tab 202 of the electrode assembly 20. In addition, the surface that protrudes further from the other surfaces of the upper cover 1 is advantageous for connection with the negative electrode tab 202. The protrusion 13 can be formed when machining the recess 12 on the surface of the upper cover 1 by a method such as press molding. That is, since the protrusion and recess are formed simultaneously on both surfaces of the upper cover 1 by the press molding process, the difficulty of machining can be reduced. The protrusion 13 is used to connect with the negative electrode tab 202 of the electrode assembly 20, and the recess 12 is used for housing and positioning.

[0062] As shown in Figure 6, in this embodiment, both the positive terminal 3 and the negative terminal 4 protrude from the first side a of the upper cover 1, thereby facilitating welding to external electrical connection components. The negative terminal 4 is formed by combining a first terminal layer 41 and a second terminal layer 42 made of different materials, and since most of the second terminal layer 42 is located within the recess 12 of the upper cover 1, the positive terminal 3 is slightly higher than the first terminal layer 41 of the negative terminal 4. In other embodiments, the connection to external electrical connection components can be further facilitated by making the negative terminal 4 thicker or the positive terminal 3 thinner, thereby making the height of the positive terminal 3 and the height of the first terminal layer 41 of the negative terminal 4 the same.

[0063] Furthermore, in this embodiment, by making both the protrusion 13 of the upper cover 1 and the positive electrode terminal 3 protrude from the second side b of the upper cover 1, electrical connection with the positive electrode tab 201 and negative electrode tab 202 of the electrode assembly 20 is facilitated. In this embodiment, the protrusion 13 that is electrically connected to the negative electrode tab 202 is formed by a press molding method, and considering the thickness and processability of the upper cover 1, it cannot protrude like the positive electrode terminal 3. Therefore, the positive electrode terminal 3 is slightly higher than the protrusion 13 of the upper cover 1. In other embodiments, by changing the processing method to make the protrusion 13 protrude further from the second side b of the upper cover 1, and making the protrusion 13 and the positive electrode terminal 3 the same height, electrical connection with the positive electrode tab 201 and negative electrode tab 202 of the electrode assembly 20 can be made even more convenient.

[0064] As shown in Figure 7b, the depth of the recess 12 is D. By making the depth D of the recess more than half the thickness of the upper cover 1, it should be ensured that the recess 12 has sufficient depth to accommodate and position the second terminal layer 42, thereby further improving the positioning accuracy of the second terminal layer 42 and the strength of the connection with the second terminal layer 42. In addition, since the upper cover 1 is manufactured using steel, it has relatively high structural strength, and even if a deeper recess is machined on the surface of the upper cover 1, it will not affect the dimensional accuracy and surface flatness of the case body.

[0065] Furthermore, by setting the depth D of the recess to 0.8 mm or more, it is possible to avoid situations where the recess is too shallow, resulting in insufficient penetration depth or insufficient welding strength when connecting the second terminal layer 42 of the negative electrode column and the upper cover 1 using welding methods such as laser welding. At the same time, by setting the depth D of the recess 12 to 2 mm or less, it is possible to avoid a situation where the strength of the rounded connection portion formed by the tensile deformation of the material between the recess 12 and the non-recessed portion of the upper cover 1 is weakened due to the recess being too deep, thereby improving processability and manufacturability.

[0066] As shown in Figure 8, there is a gap between the inner circumferential side surface c of the recess 12 of the upper cover 1 and the outer circumferential side surface d of the second terminal layer 42 of the negative electrode terminal 4 after assembly (see Figure 7b), which is convenient for installing the negative electrode terminal 4 into the recess 12 of the upper cover 1. The preferred dimensional range for this gap M is 0.1 mm ≤ M ≤ 0.2 mm. By making the gap M 0.2 mm or less, it is necessary to avoid the gap being too large, which would affect the positioning of the second terminal layer 42 in the recess 12. At the same time, by making the gap M 0.1 mm or more, it is necessary to avoid the gap being too small, which would affect the pre-installation of the second terminal layer 42 in the recess 12.

[0067] As shown in Figure 7b, there are also more preferable dimensional selection ranges for other dimensional parameters of the upper cover 1 portion of the case 10. The thickness of the second terminal layer 42 of the negative terminal 4 is T1, and the preferred dimensional selection range for thickness T1 is 0.6 mm ≤ T1 ≤ 1 mm. The thickness of the first terminal layer 41 of the negative terminal 4 is T2, and the preferred dimensional selection range for thickness T2 is 0.6 mm ≤ T2 ≤ 1 mm. The thickness of the upper cover 1 is T3, and the preferred dimensional selection range for thickness T3 is 0.8 mm ≤ T3 ≤ 1.2 mm. By making the thickness of the upper cover 1 0.8 mm or more, it is possible to avoid the impact on strength due to insufficient thickness, while at the same time, by making the thickness of the upper cover 1 1.2 mm or less, weight reduction and cost reduction are maximized while the required strength is met.

[0068] As shown in Figures 7 and 8, along the first direction A, the projection of the first terminal layer 41 on the surface of the second terminal layer 42 of the negative terminal 4 is positioned within the range of the second terminal layer 42, so that a portion of the second terminal layer 42 is not covered by the first terminal layer 41. This allows laser penetration welding to be performed on the portion of the surface of the second terminal layer 42 that is not covered by the first terminal layer 41, enabling a weld connection between the second terminal layer 42 and the upper cover 1 using laser penetration welding. Compared to other welding methods, laser penetration welding provides relatively high connection strength.

[0069] Specifically, as shown in Figures 8 and 9, in this embodiment, the area where the projection of the second terminal layer 42 is not covered by the projection of the first terminal layer 41 is an annular region 43 installed along the edge of the projection of the second terminal layer 42. That is, the first terminal layer 41 covers the central area of ​​the surface of the second terminal layer 42. The peripheral edge region of the second terminal layer 42 is not covered by the first terminal layer 41, and by performing laser penetration welding using the uncovered annular region 43, a reliable connection with the upper cover 1 is achieved by penetrating the interior of the second terminal layer 42. In this structural installation method, the first terminal layer 41 is complete and has a relatively large area, and is welded to external point connection parts, thus improving the reliability of the electrical connection.

[0070] As shown in Figures 7b and 8, the width N of the annular region 43 on the second terminal layer 42 that is not covered by the first terminal layer 41 should be set within a reasonable range. The minimum width dimension Nmin of the annular region 43 should be set to 0.4 mm or more to avoid the annular region 43 being too small to provide sufficient space for laser through welding. At the same time, the maximum width dimension Nmax of the annular region 43 should be set to 0.8 mm or less to avoid the annular region 43 being too large, which would reduce the area of ​​the first terminal layer 41 and affect welding between external electrical connection components.

[0071] As shown in Figure 2, since the material of the upper cover 1 is steel, the thickness T3 of the upper cover 1 is even thinner compared to, for example, a scheme using other aluminum alloy materials. Typically, the range is 0.8 mm ≤ T3 ≤ 1.2 mm. Therefore, when welding the negative electrode tab 202 of the electrode assembly 20 to the second side b of the upper cover 1, the upper cover 1 may melt and penetrate through to the first side a and second side b of the upper cover 1. In such a situation, after assembling the problematic upper cover 1 into the cell 100 and injecting the electrolyte, the electrolyte inside may leak from the second side b to the first side a of the upper cover 1.

[0072] To address the above-mentioned problems, in this embodiment, as shown in Figures 4 and 7a, the case 10 further includes an annular sealing member 8, which is fixed between the first side surface a of the upper cover 1 and the second terminal layer 42 of the negative electrode terminal 4, and is fixed by sandwiching the annular sealing member 8 by connecting the second terminal layer 42 and the upper cover 1. In this situation, if the welding area between the second side surface b of the upper cover 1 and the negative electrode tab 202 of the electrode assembly 20 is located within the range surrounded by the annular sealing member 8, even if the upper cover 1 melts down during the welding process, the electrolyte will remain within the range surrounded by the annular sealing member 8 even after leaking onto the first side surface a of the upper cover 1, and will not leak out further.

[0073] Specifically, as shown in Figure 10, the sealing area of ​​the annular sealing member 8 on the first side surface a of the upper cover 1 is f, and the projected area after projecting the welding area of ​​the negative electrode tab 202 of the electrode assembly and the second side surface b of the upper cover 1 onto the first side surface a of the upper cover 1 is e. As can be seen from Figure 10, on the surface of the upper cover 1, the projected area e is located within the sealing area f. Therefore, even if the upper cover 1 melts down, the leaked electrolyte is confined to the inside of the sealing area f where the annular sealing member 8 is located, and does not continue to leak out.

[0074] At the same time, when the second terminal layer 42 of the negative electrode terminal 4 and the first side surface a of the upper cover 1 are welded, the second terminal layer 42 may melt and fall off, causing the electrolyte located on the first side surface a of the upper cover 1 to continuously leak out through the melted second terminal layer 42. Therefore, in this embodiment, as shown in Figure 10, the welding area between the second terminal layer 42 of the negative electrode terminal 4 and the first side surface a of the upper cover 1 is g, and the welding area g is located outside the sealing range f of the annular sealing member 8. That is, since the welding area between the second terminal layer 42 and the upper cover 1 is located outside the annular sealing member 8, the annular sealing member 8 is installed to separate the welding area g on the first side surface a of the negative electrode terminal 4 facing the upper cover 1 from the projected area e on the first side surface a corresponding to the welding area of ​​the negative electrode tab 202 facing the upper cover 1, thereby preventing the electrolyte from continuously leaking out through the melted second terminal layer 42.

[0075] As shown in Figure 7a, in this embodiment, by installing a seal groove 44 on the surface of the second terminal layer 42 of the negative electrode terminal 4 facing the first side surface a of the upper cover 1 and housing the annular seal member 8, the annular seal member 8 is pre-positioned before the welding of the negative electrode terminal 4 and the upper cover 1 is completed, thereby improving the sealing effect. Naturally, in other embodiments, the seal groove 44 may be installed on the first side surface a of the upper cover 1, or the seal groove 44 may be installed simultaneously on the upper cover 1 and the second terminal layer 42 of the negative electrode terminal 4 to house the annular seal member 8.

[0076] As shown in Figure 4, in this embodiment, the positive electrode terminal 3 includes two parts: a positive electrode rivet joint block 31 located on the first side surface a of the upper cover 1 and a positive electrode pole 32 located on the second side surface b of the upper cover 1. The lower surface of the positive electrode pole 32 is used for electrical connection to the positive electrode tab 201 of the electrode assembly 20, and the upper end of the positive electrode pole 32 extends through a through hole 11 in the upper cover 1 and is connected to the positive electrode rivet joint block 31 by riveting. An upper insulating member 5 is installed between the positive electrode rivet joint block 31 and the upper cover 1 to provide insulation between the positive electrode rivet joint block 31 and the upper cover 1 and prevent short circuits. A lower insulating member 6 is installed between the positive electrode pole 32 and the upper cover 1 to provide insulation between the positive electrode pole 32 and the upper cover 1 and prevent short circuits. The seal ring 7 is fitted onto the pole surface of the positive pole 32, and the outer surface of the seal ring 7 contacts and seals the through hole 11 of the upper cover 1, thereby preventing the electrolyte from leaking out through the through hole 11 from the second side b of the upper cover 1.

[0077] As shown in Figure 9, in the first direction A, the shapes of both the positive terminal 3 and the negative terminal 4 are rectangular, and rounded corners are provided on all four corners of the positive terminal 3 and the negative terminal 4.

[0078] To achieve the objective of preventing rotation of the positive terminal 3, as shown in Figure 4, recesses are provided on the first side surface a of the upper cover 1 at positions corresponding to the upper insulating member 5 and the positive terminal rivet joint block 31, thereby accommodating the upper insulating member 5 and the positive terminal rivet joint block 31 and preventing rotation of the positive terminal rivet joint block 31. However, since the material of the upper cover 1 is steel and is thinner than that of an aluminum alloy material, it is not possible to provide an excessively deep recess on the upper cover 1 to accommodate the upper insulating member 5 and the positive terminal rivet joint block 31, thus limiting the rotation prevention capability. Therefore, in the second direction B perpendicular to the first direction A, the upper insulating member 5 has a positioning portion 51 that protrudes outward, and the surface of the first side surface a of the upper cover 1 has a housing portion 14 that fits with the positioning portion 51. By providing an additional contact area, the rotation prevention capability is improved by installing a positioning portion 51 that further extends onto the upper insulating member 5 within the housing portion 14 on the first side surface a of the upper cover 1. Naturally, in other embodiments, the objective of improving the anti-rotation effect may be similarly achieved by installing an outwardly protruding positioning portion 51 on the surface of the first side a of the upper cover 1 and a corresponding housing portion 14 on the upper insulating member 5.

[0079] As shown in Figures 1 and 2, the present invention provides a cell 100 including the case 10 described above. By using steel instead of aluminum alloy as the material for the top cover 1 and side case 2, structural strength can be ensured while keeping the thickness thin, thereby increasing the space utilization rate within the case 10 and improving the energy density of the cell 100. At the same time, since the negative electrode of the electrode assembly 20 of the cell 100 is drawn outward through the top cover 1, the second terminal layer 42 and the first terminal layer 41 of the negative electrode terminal 4, the number of parts required for the cell 100 can be reduced, simplifying the structure and lowering production and assembly costs. In addition, the top cover 1 and side case 2 have a negative charge by being connected to the negative electrode tab 202 of the electrode assembly 20, which prevents rust from forming.

[0080] Example 2

[0081] This embodiment provides a case 10 for use in cell 100, the structure of which is substantially the same as the case 10 provided in Embodiment 1, the difference being that in this embodiment, the case 10 includes two upper covers 1, and the positive terminal 3 and negative terminal 4 are each mounted on the two upper covers 1 (that is, both upper covers 1 in this embodiment are the case body of the case 10).

[0082] As shown in Figures 11 and 12, two openings 21 are formed by penetrating both sides of the side case 2 of the case 10, and the two upper covers 1 each seal the openings 21 on both sides of the side case 2, forming a space for housing the electrode assembly 20. As shown in Figure 11, the positive electrode terminal 3 is mounted on one upper cover 1, and its structural mounting method is the same as in Embodiment 1. As shown in Figure 12, the negative electrode terminal 4 is mounted on another upper cover 1, but its structural mounting method is the same as in Embodiment 1, so this upper cover 1 has a negative charge.

[0083] Example 3

[0084] This embodiment provides a case 10 for use in cell 100, the structure of which is substantially the same as the case 10 provided in Embodiment 1, the difference being that in this embodiment, case 10 includes an upper cover 1 and a side case 2, one end of the side case 2 is open to form an opening 21 and the other end is closed, and the upper cover 1 closes the opening 21 of the side case 2 to form a space for housing the electrode assembly 20. The positive electrode terminal 3 is installed on the side case 2 and the negative electrode terminal 4 is installed on the upper cover 1 (i.e., in this embodiment, both the side case 2 and the upper cover 1 are the case body of case 10). The negative electrode tab 202 of the electrode assembly 20 is drawn outward through the second side b of the upper cover 1, the second terminal layer 42 and the first terminal layer 41 of the negative electrode terminal 4, so the upper cover 1 has a negative charge.

[0085] Example 4

[0086] This embodiment provides a case 10 for use in cell 100, the structure of which is substantially the same as the case 10 provided in Embodiment 1, the difference being that in this embodiment, case 10 includes an upper cover 1 and a side case 2, one end of the side case 2 is open to form an opening 21 and the other end is closed, and the upper cover 1 closes the opening 21 of the side case 2 to form a space for housing the electrode assembly 20. The positive electrode terminal 3 is installed on the upper cover 1 and the negative electrode terminal 4 is installed on the side case 2 (i.e., in this embodiment, both the side case 2 and the upper cover 1 are the case body of case 10). Therefore, in this embodiment, the negative electrode tab 202 of the electrode assembly 20 is drawn outward through the side case 2 and the second terminal layer 42 and first terminal layer 41 of the negative electrode terminal 4, so the side case 2 has a negative charge.

[0087] Example 5

[0088] This embodiment provides a case 10 for use in cell 100, the structure of which is substantially the same as the case 10 provided in Embodiment 1, the difference being that in this embodiment, case 10 includes an upper cover 1 and a side case 2, one end of the side case 2 is open to form an opening 21 and the other end is closed, and the upper cover 1 closes the opening 21 of the side case 2 to form a space for housing the electrode assembly 20. Both the positive electrode terminal 3 and the negative electrode terminal 4 are installed on the side case (i.e., the side case 2 in this embodiment is the case body of case 10). Therefore, in this embodiment, the negative electrode tab 202 of the electrode assembly 20 is drawn outward through the side case 2, the second terminal layer 42 and the first terminal layer 41 of the negative electrode terminal 4, so the side case 2 has a negative charge.

[0089] Naturally, in other embodiments, the positive terminal 3 and negative terminal 4 may be mounted on any part of the case 10, such as the upper cover 1 or side case 2, as required by actual needs, with the positive tab 201 of the electrode assembly 20 being drawn outward through the positive terminal 3 which is insulated from the case 10, and the negative tab 202 being drawn outward in sequence through the case 10 and the negative terminal 4. The specific mounting positions of the positive terminal 3 and negative terminal 4 can be set according to actual design requirements.

[0090] Although specific embodiments of the present invention have been described above, those skilled in the art should understand that this is merely an illustrative description and that the scope of protection of the present invention is limited by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments, provided that they do not depart from the principles and substance of the present invention, and such changes and modifications are all within the scope of protection of the present invention. [Industrial applicability]

[0091] The cell case body and the cell containing it according to the present invention can be applied in the field of battery technology. [Explanation of symbols]

[0092] 100 cells 10 cases 1. Top cover A 1st direction B Second direction 11 Through hole 12 recesses 13 Convex part 14. Detention Unit 15 Liquid injection hole 2 Side Case 21 Opening 3. Positive terminal 31 Positive electrode rivet joint block 32 Positive Polarity Column 4 Negative terminal 41 1st terminal layer 42 2nd terminal layer 43 Circular Region 44 Seal groove 5. Upper insulating member 51 Positioning section 6. Lower insulating member 7 Seal ring 8. Annular sealing member 20 Electrode Assembly 201 Positive Tab 202 Negative Electrode Tab 30 Insulating Sheets

Claims

1. A through hole is provided, the material is steel, the thickness direction is the first direction, and the case body includes opposing first and second sides in the first direction, The positive terminal that penetrates the aforementioned through hole, An upper insulating member is installed between the positive terminal and the case body to insulate the positive terminal from the case body, A negative terminal comprising a first terminal layer and a second terminal layer installed along the first direction, wherein the first terminal layer and the second terminal layer are electrically connected, the second terminal layer is electrically connected to the first side surface, the material of the second terminal layer is steel, and the material of the first terminal layer is different from the material of the second terminal layer, Cases of cells that include this.

2. The cell case according to claim 1, wherein the first side surface has a recess formed to be recessed toward the second side surface, and at least a portion of the second terminal layer is housed in the recess.

3. The cell case according to claim 2, wherein the depth of the recess of the recess is more than half the thickness of the case body.

4. The case of the cell according to claim 2, wherein the depth of the recess of the recess is D, and 0.8 mm ≤ D ≤ 2 mm.

5. The case of the cell according to claim 2, wherein the second side surface has a protrusion corresponding to the position of the recess.

6. The cell case according to claim 5, wherein both the positive terminal and the negative terminal are installed on the first side surface of the case body, and on the second side surface, the height of the protrusion and the positive terminal are the same.

7. The cell case according to claim 2, wherein there is a gap between the inner circumferential surface of the recess and the outer circumferential surface of the second terminal layer, and the dimension of the gap is M, where 0.1 mm ≤ M ≤ 0.2 mm.

8. In the first side view, the surface of the second terminal layer and the surface of the case body are on the same plane, and / or The cell case according to claim 2, wherein the surface of the first terminal layer protrudes from the surface of the case body on the first side surface.

9. The case of the cell according to claim 1, wherein, along the first direction, the projection of the first terminal layer on the surface of the second terminal layer is located within the range of the second terminal layer.

10. The cell according to claim 9, wherein, along the first direction, the region of the projection of the second terminal layer that is not covered by the projection of the first terminal layer is an annular region located along the edge of the projection of the second terminal layer.

11. The minimum width dimension of the annular region is Nmin, and Nmin ≥ 0.4 mm. and / or the case of the cell according to claim 10, wherein the maximum width dimension of the annular region is Nmax and Nmax ≤ 0.8 mm.

12. The cell case according to claim 1, wherein the case further includes an annular sealing member, and the annular sealing member is fixed between the second terminal layer and the first side surface of the case body.

13. The cell case according to claim 12, wherein the welding area between the second terminal layer and the case body is located outside the annular sealing member.

14. The cell case according to claim 13, wherein the surface of the second terminal layer facing the first side surface and / or the first side surface further has a seal groove for accommodating the annular seal member.

15. The cell case according to claim 1, wherein in a second direction perpendicular to the first direction, one of the upper insulating member and the case body has a positioning portion that protrudes outward, and the other has a housing portion that fits with the positioning portion.

16. The case for a cell according to claim 1, wherein the case body includes an upper cover and a side case, the upper cover is electrically connected to an opening in the side case, and the upper cover and the side case surround and form a housing space.

17. The material of the case body and the second terminal layer is 304 stainless steel, and / or In the first direction, the shape of the negative terminal is rectangular, and rounded corners are provided on the four corners of the negative terminal, and / or In the first aspect, the height of the positive terminal and the height of the first terminal layer are the same, and / or The thickness of the second terminal layer is T １ Therefore, 0.6 mm ≤ T １ ≤ 1 mm and / or, The thickness of the first terminal layer is T ２ Therefore, 0.6 mm ≤ T ２ ≤ 1 mm and / or, The thickness of the case body is T ３ Therefore, 0.8 mm ≤ T ３ The case of the cell according to claim 1, wherein the size is ≤ 1.2 mm.

18. A cell, including the case of a cell according to any one of claims 1 to 17.

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