Battery cell
By setting a thinner second sub-region in the side plate of the casing, the problem of lithium deposition at the edge of the bare cell during fast charging cycles is solved, improving the fast charging cycle performance and service life of the cell.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-07
- Publication Date
- 2026-04-14
AI Technical Summary
During fast charging cycles, the graphite on the negative electrode expands, causing increased internal stress in the battery cell. This can lead to lithium plating at the edge of the bare cell or a drop in battery cell performance during cycles, especially at the edge of the positive electrode.
A thinner second sub-region is set in the side plate of the casing, surrounding the edge of the first sub-region, providing more space to accommodate the edge of the bare cell when it expands, reducing constraint and reducing the risk of lithium plating.
By reducing the constraint force at the edge of the bare cell, the risk of lithium plating at the edge of the bare cell is reduced, thereby improving the fast charging cycle performance and lifespan of the cell.
Smart Images
Figure CN224123411U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy storage technology, and in particular to a battery cell. Background Technology
[0002] The battery cell may include a housing and a cover assembly, the cover assembly being closed onto the open end of the housing, and the housing and cover assembly together forming a receiving space for accommodating a bare battery cell (such as a bare battery cell with a wound structure or a bare battery cell with a stacked structure).
[0003] During long-term fast charging cycles (equivalent charging rate of no less than 1.5C for 10%-80% SOC), the graphite expansion on the negative electrode plate increases the internal stress of the cell. Near the edges of the positive electrode plate (especially the upper and lower edges along the height of the casing), the expansion stress is even greater due to the constraints of the cover assembly and the casing, making the edge region of the positive electrode plate prone to lithium plating or cycle failure. Utility Model Content
[0004] In view of this, the purpose of this application is to propose a battery cell that at least partially solves the problem of lithium plating at the edge of the bare battery cell or the problem of poor cycle performance caused by the edge of the bare battery cell being squeezed.
[0005] Based on the above objectives, this application provides a battery cell, comprising: a housing including a plurality of side plates, the plurality of side plates forming an open end of the housing; at least one of the side plates including a receiving area, the receiving area including a first sub-region and a second sub-region disposed along at least one edge of the first sub-region; a bare battery cell including a bare battery cell body, the orthographic projection of the bare battery cell body on the housing along a first direction being defined as the bare battery cell projection, the bare battery cell projection covering the first sub-region, and at least a portion of the edge of the bare battery cell projection located within the second sub-region; the first direction being perpendicular to the surface of the receiving area adjacent to the bare battery cell; wherein, the thickness of the second sub-region is less than the thickness of the first sub-region.
[0006] Optionally, the second sub-region is set around the edge of the first sub-region.
[0007] Optionally, the second sub-region is connected to the first sub-region, the edge of the second sub-region closer to the first sub-region is defined as the inner edge, the edge of the second sub-region farther from the first sub-region is defined as the outer edge, and the thickness of the second sub-region gradually decreases from the inner edge to the adjacent outer edge.
[0008] Optionally, the orthographic projection of the first sub-region along the first direction is defined as the first sub-projection, and the orthographic projection of the accommodating region along the first direction is defined as the accommodating region projection, and the ratio of the area of the first sub-projection to the area of the accommodating region projection is 0.46.
[0009] Optionally, the first sub-projection and the projection of the receiving area are similar in shape.
[0010] Optionally, both the first sub-projection and the receiving area projection are rectangular, with the length of the first sub-projection being W1 and the width being H1, and the length of the receiving area projection being W2 and the width being H2.
[0011] W1 / H1 = W2 / H2.
[0012] Optionally, the minimum thickness of the second sub-region is L1.
[0013] L1=(1-EOH)*2mm
[0014] Wherein, EOH represents the cell's health at the end of its lifespan, which is 80% or 70% SOH; and / or,
[0015] The second sub-region includes an outer edge, and the surface of the second sub-region near the bare cell has a gentle curve in a cross-section perpendicular to the outer edge, the expression of which is:
[0016] Y = -4.025 * x 2 +2.5284*x+0.0024
[0017] Where Y is the thickness difference between a preset point on the curve and the outer edge; the distance from the preset point to the outer edge along the second direction is P; the dimension of the projection of the receiving area along the second direction is Q; and x is P / Q; the second direction is perpendicular to the outer edge.
[0018] Optionally, a connection area is provided between the receiving area and the opening end along the height direction of the housing, and the battery cell further includes a cover plate assembly that covers the opening end, wherein the orthographic projection of the cover plate assembly along a first direction on the side plate does not exceed the edge of the connection area near the receiving area.
[0019] Optionally, the thickness of the connecting region is not less than the thickness of the accommodating region.
[0020] Optionally, the side plate includes two first side plates disposed opposite each other along the width direction of the housing, and two second side plates disposed opposite each other along the length direction of the housing; the surface area of the first side plate is larger than the surface area of the second side plate, and the accommodating area is at least disposed in the first side plate.
[0021] As can be seen from the above, the battery cell provided in this application reduces the thickness of the second sub-region corresponding to the edge of the bare battery cell body in the side plate, thereby creating a larger space between the bare battery cell body and the second sub-region. When the bare battery cell expands, the edge of the bare battery cell body can enter the aforementioned space, reducing the constraint force on the edge of the bare battery cell body. This helps to reduce the risk of lithium plating at the edge of the bare battery cell, improves the fast charging cycle performance of the battery cell, and extends the battery cell's lifespan. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 This is a front view schematic diagram of the battery cell according to an embodiment of this application;
[0024] Figure 2 for Figure 1 A schematic diagram of the first structure of the AA section;
[0025] Figure 3 for Figure 1 A schematic diagram of the first structure with the BB section in the middle;
[0026] Figure 4 for Figure 1 A schematic diagram of the second structure of section AA;
[0027] Figure 5 for Figure 1 A schematic diagram of the second structure with the BB section in the middle;
[0028] Figure 6 This is a schematic diagram of the first side plate of the second structure;
[0029] Figure 7 for Figure 4 An enlarged schematic diagram of section C;
[0030] Figure 8 for Figure 4 An enlarged schematic diagram of part D in the middle.
[0031] Explanation of reference numerals in the attached figures:
[0032] 100. Shell; 110. Side plate; 111. First side plate; 112. Second side plate; 113. Receiving area; 1131. First sub-area; 1132. Second sub-area; 1133. Inner edge; 1134. Outer edge; 114. Connecting area; 120. Base plate; 130. Opening end;
[0033] 200, Cover plate assembly; 210, Cover plate body; 220, Pole post; 230, First insulator;
[0034] 300. Accommodation space;
[0035] 400. Bare battery cell; 410. Bare battery cell body. Detailed Implementation
[0036] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.
[0037] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components described in these embodiments do not limit the scope of this application.
[0038] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.
[0039] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.
[0040] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0041] Figure 1 A front-view schematic diagram of the battery cell is shown. Figure 2 Showing Figure 1 A schematic diagram of the first structure with section AA in the middle. Figure 3 Showing Figure 1 A schematic diagram of the first structure with the BB section in the middle.
[0042] like Figure 1 , Figure 2 and Figure 3 The battery cell includes a housing 100 (the housing 100 may be made of aluminum), the housing 100 includes a plurality of side plates 110, and the plurality of side plates 110 together form an open end 130 of the housing 100. For example, the plurality of side plates 110 include those along the width direction of the housing (e.g., ...). Figure 3 Two first side plates 111 are arranged opposite each other in the Y direction of the shell, and along the length direction of the shell (e.g., Figure 3 The battery cell includes two second side plates 112 arranged opposite each other in the X direction. The two first side plates 111 and the two second side plates 112 together form an opening end 130. The housing 100 also includes a bottom plate 120 arranged opposite to the opening end 130, and all the side plates 110 are connected to the bottom plate 120. The battery cell also includes a cover plate assembly 200 that covers the opening end 130, and the cover plate assembly 200 and the housing 100 together form a receiving space 300. The cover plate assembly 200 may include a cover plate body 210 connected to the housing 100 (e.g., welded), an electrode post 220 that penetrates and connects to the cover plate body 210, and a first insulator 230 connected to the cover plate body 210 and located within the receiving space 300.
[0043] like Figure 2 and Figure 3 The space 300 also contains a bare battery cell 400, which includes a bare battery cell body 410 and tabs connected to the bare battery cell body 410. The bare battery cell body 410 is electrically connected to the corresponding terminal 220 through the tabs. The bare battery cell body 410 includes multiple positive electrode plates, multiple negative electrode plates, and a separator that isolates the positive and negative electrode plates. The upper edge of the electrode plate (including the positive electrode plate and / or the negative electrode plate) is close to the cover plate assembly 200, and the lower edge of the electrode plate is close to the base plate 120.
[0044] Combination Figure 2 and Figure 3 The structure and orientation shown will be further explained, taking the first side plate 111 as an example, along the height direction of the shell (e.g. Figure 2 In the Z direction of the shell, a cover plate assembly 200 is provided near the upper edge of the first side plate 111, and a bottom plate 120 is provided near the lower edge; along the length direction of the shell (e.g., in the Z direction), a cover plate assembly 200 is provided near the upper edge of the first side plate 111, and a bottom plate 120 is provided near the lower edge of the first side plate 111; Figure 3In the X direction, second side plates 112 are respectively provided near the left and right edges of the first side plate 111. It can be seen that structural components are provided around the four edges of the first side plate 111. If the thickness of the first side plate 111 is uniform, during fast charging cycles, the edges of the bare cell body 410 are subject to greater constraint forces due to their proximity to the aforementioned structural components, while the middle part of the bare cell body 410 (i.e., the position corresponding to the middle of the first side plate 111) is subject to relatively less constraint forces due to its distance from the aforementioned structural components. Therefore, the bare cell 400 is prone to lithium plating (i.e., lithium plating at the edge of the bare cell) at the location where the constraint forces are greater, i.e., the edge of the bare cell body 410, leading to a drop in fast charging speed.
[0045] To improve the above situation, the structure of the side plate 110 can be changed to provide more space near the edge of the bare cell body 410, thereby achieving a certain degree of clearance when the bare cell 400 expands, and reducing the constraint force on the edge of the bare cell body 410.
[0046] Specifically, Figure 4 Showing Figure 1 A schematic diagram of the second structure of section AA. Figure 5 Showing Figure 1 A schematic diagram of the second structure of the BB section. Figure 6 A schematic diagram of the first side plate 111 of the second structure is shown.
[0047] like Figure 4 , Figure 5 and Figure 6 The battery cell provided in this embodiment includes: a housing 100, at least one side plate 110 including a receiving region 113, the receiving region 113 including a first sub-region 1131, and a second sub-region 1132 disposed along at least one side edge of the first sub-region 1131 (e.g., ...). Figure 6 (The dotted pattern area in the middle); bare cell 400, bare cell body 410 along the first direction (when the receiving area 113 is disposed on the first side plate 111, the first direction is) Figure 5 and Figure 6 The orthographic projection of the bare cell (in the Y direction) onto the housing 100 is defined as the bare cell projection, which covers the first sub-region 1131, and at least a portion of the edge of the bare cell projection is located within the second sub-region 1132; the first direction is perpendicular to the surface of the receiving region 113 near the bare cell 400; wherein the thickness of the second sub-region 1132 is less than the thickness of the first sub-region 1131.
[0048] For example, with Figure 6 Taking the structure and orientation shown as an example, along the longitudinal direction (e.g.) Figure 6In the Z direction), the second sub-region 1132 can be set above and / or below the first sub-region 1131; along the horizontal direction (e.g., Figure 6 (in the X direction), the second sub-region 1132 can be located to the left and / or right of the first sub-region 1131. Adjacent second sub-regions 1132 can be connected.
[0049] For example, the receiving area 113 may be provided only on one of the first side plates 111 of the housing 100; or only on one of the second side plates 112 of the housing 100; or only on both first side plates 111 of the housing 100; or only on both second side plates 112 of the housing 100; or only on one of the first side plates 111 and one of the second side plates 112 of the housing 100; or on all the side plates 110 of the housing 100.
[0050] For example, in the housing 100, only one first side plate 111 may not have a receiving area 113; or only one second side plate 112 may not have a receiving area 113.
[0051] For example, the first sub-region 1131 is aligned with or offset from the projection center of the bare cell.
[0052] In this embodiment, because the second sub-region 1132 is thinner, it occupies less of the internal accommodating space 300 of the housing 100, resulting in a larger space between the second sub-region 1132 and the bare cell body 410. When the bare cell 400 undergoes a fast charging cycle, the portion of the bare cell body 410 near its edge can expand and enter the larger space between it and the second sub-region 1132, thereby reducing the constraint force on the portion of the bare cell body 410 near its edge.
[0053] The battery cell provided in this application embodiment reduces the thickness of the second sub-region 1132 in the side plate 110 corresponding to the edge of the bare cell body 410, thereby creating a larger space between the bare cell body 410 and the second sub-region 1132. When the bare cell 400 expands, the edge of the bare cell body 410 can enter the aforementioned space, reducing the constraint force on the edge of the bare cell body 410. This helps reduce the risk of lithium plating at the edge of the bare cell 400, improves the fast charging cycle performance of the cell, and extends the cell's lifespan.
[0054] like Figure 6 In some embodiments, the second sub-region 1132 is arranged around the edge of the first sub-region 1131.
[0055] In this embodiment, the second sub-region 1132 is arranged in a ring around the first sub-region 1131. At this time, all edges of the bare cell projection are located within the second sub-region 1132. That is to say, a large space can be provided for all edges of the bare cell body 410 near the receiving area 113, so as to further reduce the constraint force on the edges of the bare cell body 410, thereby further reducing the risk of lithium plating at the edges of the bare cell 400, and improving the fast charging cycle trend and service life of the cell.
[0056] Figure 7 Showing Figure 4 An enlarged schematic diagram of section C.
[0057] like Figure 6 and Figure 7 In some embodiments, the second sub-region 1132 is connected to the first sub-region 1131, the edge of the second sub-region 1132 that is close to the first sub-region 1131 is defined as the inner edge 1133, the edge of the second sub-region 1132 that is far from the first sub-region 1131 is positioned as the outer edge 1134, and the thickness of the second sub-region 1132 gradually decreases from the inner edge 1133 to the adjacent outer edge 1134.
[0058] For example, the thickness variation of the second sub-region 1132 can be continuous or phased. When the thickness of the second sub-region 1132 is continuous, the surface of the second sub-region 1132 is constructed as a smooth inclined surface or curved surface; when the thickness of the second sub-region 1132 is phased, the surface of the second sub-region 1132 is constructed as a stepped surface or a step-like surface.
[0059] For example, the inner surface of the second sub-region 1132 (i.e., the surface near the bare cell body 410) can be a smooth curved surface to prevent stress concentration in the second sub-region 1132 and avoid adverse effects on the mechanical strength of the housing 100.
[0060] For example, the outer surface of the second sub-region 1132 (i.e., the surface away from the bare cell body 410) can coincide with the outer surface of the first sub-region 1131. In this case, the entire outer surface of the side plate 110 is a smooth and flat surface, which helps the housing 100 resist external impact forces and facilitates the assembly and transportation of the cell.
[0061] like Figure 6For the second sub-region 1132, the inner edge 1133 is closer to the center of the bare cell projection, while the outer edge 1134 is closer to the edge of the bare cell projection. Based on the foregoing, the closer the bare cell body 410 is to the edge, the more prone it is to lithium plating at the bare cell edge. In this embodiment, the thickness of the second sub-region 1132 is designed as a variable thickness structure according to this principle; that is, the thickness is smaller closer to the outer edge 1134. This reduces the impact on the mechanical strength of the housing 100 due to thinning, preventing breakage of the housing 100 during assembly and use at the second sub-region 1132, thus improving the cell's sealing and safety. Furthermore, by further thinning the area near the edge of the bare cell body 410, more expansion space is provided for the edge of the bare cell body 410 when the bare cell 400 expands, further reducing the constraint force on the edge of the bare cell body 410 and further reducing the risk of lithium plating at the bare cell edge.
[0062] like Figure 6 In some embodiments, the orthographic projection of the first sub-region 1131 along the first direction is defined as the first sub-projection, and the orthographic projection of the accommodating region 113 along the first direction is defined as the accommodating region projection. The ratio of the area S1 of the first sub-projection to the area S2 of the accommodating region projection is 0.46, that is, S1 = 0.46 * S2.
[0063] If the area of S1 is too large, it will excessively encroach on the space of the second sub-region 1132. Consequently, the space provided by the second sub-region 1132 for the bare cell body 410 will be relatively small, and its effect on improving lithium plating at the edge of the bare cell will be minimal. If the area of S1 is too small, the second sub-region 1132 will be located over a large area on the side plate 110, which may affect the mechanical strength of the casing 100, thereby adversely affecting the sealing and safety of the cell.
[0064] To avoid the aforementioned problems, in this embodiment, S1:S2 is designed to be 0.46, which provides sufficient expansion space for the edge of the bare cell body 410, thereby significantly reducing the risk of lithium plating at the edge of the bare cell. Simultaneously, the relatively large thickness of the first sub-region 1131 and its reasonably set area ensure the mechanical strength of the casing 100, contributing to the sealing and safety of the cell.
[0065] like Figure 6 In some embodiments, the first sub-projection and the receiving area projection are similar in shape, that is, the first sub-projection and the receiving area projection have the same shape but different sizes.
[0066] The shape of the side plate 110 is designed based on the shape of the bare cell body 410. Correspondingly, the shape of the receiving area 113 in the side plate 100 can also match the shape of the bare cell projection. When the shape of the first sub-projection is similar to the shape of the receiving area projection, the first sub-region 1131 and the second sub-region 1132 can better correspond to the bare cell body 410, so as to prevent the second sub-region 1132 from being misaligned with the edge of the bare cell body 410.
[0067] When the bare cell 400 expands, the edge of the bare cell body 410 can smoothly enter the larger space between it and the second sub-region 1132, thereby effectively reducing the constraint force on the edge of the bare cell body 410 and further reducing the risk of lithium plating at the edge of the bare cell.
[0068] To improve the energy density of the battery cell and the battery pack including the cell, the bare cell body 410 can be designed as a rectangular or near-rectangular structure. Accordingly, the projection of the bare cell is rectangular.
[0069] To better achieve the aforementioned effects, such as Figure 6 In some embodiments, both the first sub-projection and the receiving area projection are rectangular, with the length of the first sub-projection being W1 and the width being H1, and the length of the receiving area projection being W2 and the width being H2.
[0070] W1 / H1 = W2 / H2.
[0071] When both the first sub-projection and the receiving area projection are rectangular and satisfy the above length-width relationship, it is easier to realize that the first sub-region 1131 corresponds to the middle of the bare cell body 410. Then, the second sub-region 1132 set along the edge of the first sub-region 1131 is also easier to realize that it corresponds to the edge of the bare cell body 410, thereby reducing the constraint force on the edge of the bare cell body 410 when the bare cell 400 expands.
[0072] like Figure 5 and Figure 7 In some embodiments, the minimum thickness of the second sub-region 1132 is L1.
[0073] L1=(1-EOH)*2mm
[0074] EOH represents the cell's health at the end of its lifespan, and is either 80% or 70% SOH.
[0075] If L1 is too large, the space provided by the second sub-region 1132 for the bare cell body 410 will be correspondingly smaller, and its effect on improving lithium plating at the edge of the bare cell will not be significant. If L1 is too small, it may affect the mechanical strength of the casing 100, thereby adversely affecting the sealing and safety of the cell.
[0076] To avoid the above problems, this embodiment designs the minimum thickness L1 of the second sub-region 1132 according to the parameters of the bare cell 400, so that the space provided by the second sub-region 1132 can match the expansion amount of the bare cell 400. This ensures that the second sub-region 1132 can provide sufficient expansion space for the edge of the bare cell body 410, and also prevents the second sub-region 1132 from having an adverse effect on the mechanical strength of the casing 100, thus helping to ensure the sealing and safety of the cell.
[0077] Figure 8 Showing Figure 4 An enlarged diagram of part D, as shown below. Figure 4 , Figure 5 , Figure 6 and Figure 8 In some embodiments, the surface of the second sub-region 1132 near the bare cell 400 has a gentle curve in a cross-section perpendicular to the outer edge 1134, and the expression for the curve is:
[0078] Y = -4.025 * x 2 +2.5284*x+0.0024
[0079] Where Y is the thickness difference between a preset point on the curve and the outer edge 1134; the preset point is along the second direction (e.g., Figure 8 The distance from the Z direction to the outer edge 1134 is P, the dimension of the projection of the receiving area along the second direction is Q, and x is P / Q; the second direction is perpendicular to the outer edge 1134.
[0080] like Figure 6 When the preset point is in the second sub-region 1132 above or below the first sub-region 1131, the value of Q is H2; when the preset point is in the second sub-region 1132 to the left or right of the first sub-region 1131, the value of Q is W2.
[0081] by Figure 8 The structure and orientation shown are used as an example for explanation. The preset point is point E located below the first sub-region 1131. Figure 8 The curve shown passes through the outer edge 1134 (hereinafter referred to as the lower outer edge) located below the first sub-region 1131. Y is the thickness difference between point E and the lower outer edge, P is the distance between point E and the lower outer edge along the second direction, and Q is the value of H2, that is, x = P / H2.
[0082] By structurally designing the thickness variation of the second sub-region 1132 using the above expression, the thickness variation of the second sub-region 1132 can better conform to the shape of the bare cell body 410 when the bare cell 400 expands, thereby further reducing the constraint force on the edge of the bare cell body 410 when the bare cell 400 expands.
[0083] like Figure 4 and Figure 7 In some embodiments, along the height direction of the housing (e.g.) Figure 4 In the Z direction), a connecting region 114 is provided between the receiving region 113 and the opening end 130. The orthographic projection of the cover plate assembly 200 on the side plate 110 along the first direction (hereinafter referred to as the cover plate projection) does not exceed the edge of the connecting region 114 near the receiving region 113 (hereinafter referred to as the lower edge of the connecting region 114).
[0084] For example, the cover plate projection is located above the lower edge of the connection area 114; or, the lower edge of the cover plate projection is aligned with the lower edge of the connection area 114.
[0085] For example, along the height direction of the housing, the bare cell body 410 is located below the connection area 114.
[0086] by Figure 7 Taking the structure shown as an example for further explanation, a portion of the cover assembly 200 (e.g., the first insulator 230) extends into the receiving space 300, and the bare cell body 410 is located below the cover assembly 200. In other words, the portion of the side plate 110 near the opening end 130 does not correspond to the bare cell body 410, but rather to the portion of the cover assembly 200 that extends into the receiving space 300.
[0087] If the second sub-region 1132 extends to the opening end 130, then, as can be seen from the foregoing, the thinner part of the second sub-region 1132 near the outer edge 1134 will no longer correspond to the edge of the bare cell body 410, but will correspond to the cover plate assembly 200. The part of the second sub-region 1132 with a larger thickness will correspond to the edge of the bare cell body 410. That is, the second sub-region 1132 will be misaligned with the edge of the bare cell body 410, which will reduce the effect of improving the lithium plating at the edge of the bare cell.
[0088] To avoid the above problems, this embodiment provides a connecting region 114 between the receiving area 113 and the opening end 130, so that the connecting region 114 corresponds to the part of the cover plate assembly 200 that extends into the receiving space 300, thereby enabling the edge of the bare cell body 410 to better correspond to the second sub-region 1132 in the receiving area 113, and more effectively reducing the constraint force on the edge of the bare cell body 410.
[0089] like Figure 7 In some embodiments, the thickness of the connecting region 114 is not less than the thickness of the receiving region 113.
[0090] like Figure 6 The dimension of the connecting region 114 along the height direction of the shell is h.
[0091] For example, the thickness of the connecting region 114 can be the same as the thickness of the first sub-region 1131.
[0092] In order to improve the mechanical strength of the connection between the side plate 110 and the cover plate assembly 200, the thickness of the connection area 114 needs to be designed to be larger so that a reliable connection can be formed between the cover plate assembly 200 and the housing 100, ensuring the sealing and safety of the battery cell.
[0093] like Figure 5 In some embodiments, the surface area of the first side plate 111 is larger than the surface area of the second side plate 112, and the accommodating area 113 is at least disposed in the first side plate 111.
[0094] The first side plate 111 has a larger surface area, and correspondingly, the first side plate 111 corresponds to the sidewall of the bare cell body 410 with a larger surface area. If the constraint force on this surface of the bare cell body 410 is smaller, the risk of lithium plating at the edge of the bare cell can be significantly reduced, thereby more significantly improving the fast charging cycle trend of the cell and increasing the lifespan of the cell.
[0095] It should be noted that some embodiments of this application have been described above. Other embodiments are within the scope of the appended claims.
[0096] The various embodiments in this application are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0097] The description in this application is given for illustrative purposes and is not intended to be exhaustive or to limit the application to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of this application and to enable those skilled in the art to understand this application and design various embodiments with various modifications suitable for a particular purpose.
[0098] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application is limited to these examples; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in detail for the sake of brevity.
[0099] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.
[0100] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.
Claims
1. A battery cell, characterized in that, include: The housing includes a plurality of side plates, the plurality of side plates enclosing an open end of the housing; at least one of the side plates includes a receiving area, the receiving area including a first sub-region and a second sub-region disposed along at least one edge of the first sub-region; A bare battery cell includes a bare battery cell body, wherein the orthographic projection of the bare battery cell body onto the housing along a first direction is defined as the bare battery cell projection, the bare battery cell projection covers a first sub-region, and at least a portion of the edge of the bare battery cell projection is located within a second sub-region; the first direction is perpendicular to the surface of the receiving region adjacent to the bare battery cell; The thickness of the second sub-region is less than the thickness of the first sub-region.
2. The battery cell according to claim 1, characterized in that, The second sub-region is set around the edge of the first sub-region.
3. The battery cell according to claim 1, characterized in that, The second sub-region is connected to the first sub-region. The edge of the second sub-region closer to the first sub-region is defined as the inner edge, and the edge of the second sub-region farther from the first sub-region is defined as the outer edge. The thickness of the second sub-region gradually decreases from the inner edge to the adjacent outer edge.
4. The battery cell according to claim 1, characterized in that, The orthographic projection of the first sub-region along the first direction is defined as the first sub-projection, and the orthographic projection of the accommodating region along the first direction is defined as the accommodating region projection. The ratio of the area of the first sub-projection to the area of the accommodating region projection is 0.
46.
5. The battery cell according to claim 4, characterized in that, The first sub-projection and the projection of the receiving area are similar in shape.
6. The battery cell according to claim 5, characterized in that, Both the first sub-projection and the receiving area projection are rectangular. The length of the first sub-projection is W1 and the width is H1, and the length of the receiving area projection is W2 and the width is H2. W1 / H1 = W2 / H2.
7. The battery cell according to claim 1, characterized in that, The minimum thickness of the second sub-region is L1. L1=(1-EOH)*2mm Wherein, EOH represents the cell's health at the end of its lifespan, which is 80% or 70% SOH; and / or, The second sub-region includes an outer edge, and the surface of the second sub-region near the bare cell has a gentle curve in a cross-section perpendicular to the outer edge, the expression of which is: Y = -4.025x² + 2.5284x + 0.0024 Where Y is the thickness difference between the preset point on the curve and the outer edge; the distance from the preset point to the outer edge along the second direction is P, the dimension of the projection of the receiving area along the second direction is Q, and x is P / Q; the second direction is perpendicular to the outer edge.
8. The battery cell according to claim 1, characterized in that, Along the height direction of the housing, a connection area is provided between the receiving area and the opening end. The battery cell also includes a cover plate assembly that covers the opening end. The orthogonal projection of the cover plate assembly along a first direction onto the side plate does not exceed the edge of the connection area near the receiving area.
9. The battery cell according to claim 8, characterized in that, The thickness of the connecting region is not less than the thickness of the accommodating region.
10. The battery cell according to claim 1, characterized in that, The side plate includes two first side plates arranged opposite each other along the width direction of the shell, and two second side plates arranged opposite each other along the length direction of the shell; the surface area of the first side plate is larger than the surface area of the second side plate, and the accommodating area is at least provided in the first side plate.