Battery cover plate assembly and battery monomer

Abstract

The utility model provides a battery cover plate assembly and a battery cell. The battery cover plate assembly is used for covering a shell of a single battery and comprises a cover plate body and an insulating plate, and the cover plate body is provided with a first narrow edge and a second narrow edge which are opposite to each other, a first long edge and a second long edge which are opposite to each other, and a liquid injection hole; the insulating plate comprises an insulating plate main body, a shielding bottom and a connecting side part, the insulating plate main body is located on the inner side of the cover plate body, the shielding bottom is located on the side, opposite to the cover plate body, of the insulating plate main body, the orthographic projection of the shielding bottom on the cover plate body at least partially coincides with the liquid injection hole, and the connecting side part is connected between the shielding bottom and the insulating plate main body; one end of the connecting side part is connected with the shielding bottom, the other end of the connecting side part is connected with the insulating plate main body, at least one liquid outlet is defined by the connecting side part, the liquid outlet direction of the liquid outlet faces the first narrow edge or the second narrow edge, the orthographic projection length of the liquid outlet on the first long edge is a, the length of the first long edge is b, and a / b is larger than or equal to 0 and smaller than or equal to 0.03.

Description

Technical Field

[0001] This disclosure relates to the field of battery technology, and in particular to a battery cover assembly and a battery cell. Background Technology

[0002] In related technologies, a rechargeable battery (referring to a battery that can be recharged after discharge to activate its active materials and continue to be used, also known as a secondary battery, and referred to as a battery in this article) includes a battery case and multiple battery cells connected in series and / or parallel within the battery case. A battery cell is the smallest unit in a battery that provides energy. Taking a lithium-ion battery cell as an example, it mainly relies on the movement of lithium ions between the positive and negative electrodes for charging and discharging.

[0003] How to alleviate the wrinkling phenomenon of the negative electrode sheet inside the battery cell and thus improve the safety of the battery cell is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0004] This disclosure provides a battery cover assembly and a battery cell to alleviate the wrinkling phenomenon of the negative electrode sheet inside the battery cell, thereby improving the safety of the battery cell.

[0005] According to one aspect of this disclosure, a battery cover assembly is provided for covering a battery cell housing. The battery cover assembly includes a cover body and an insulating plate, wherein: the cover body has opposing first narrow sides and second narrow sides, opposing first long sides and second long sides, and an injection hole; the insulating plate includes an insulating plate body, a shielding bottom, and a connecting side, wherein the insulating plate body is located inside the cover body, the shielding bottom is located on the side of the insulating plate body opposite to the cover body, and the orthographic projection of the shielding bottom on the cover body at least partially coincides with the injection hole; the connecting side connects between the shielding bottom and the insulating plate body, one end of the connecting side is connected to the shielding bottom, and the other end of the connecting side is connected to the insulating plate body; the connecting side defines at least one liquid outlet, the liquid outlet's discharge direction is towards the first narrow side or the second narrow side, the orthographic projection length of the liquid outlet on the first long side is a, and the length of the first long side is b, wherein 0 ≤ a / b ≤ 0.03.

[0006] In some embodiments, 0.6 mm ≤ a ≤ 4.5 mm, 148 mm ≤ b ≤ 206 mm.

[0007] In some embodiments, the opening area S of the liquid outlet satisfies: 16.5 mm² ≤ S ≤ 28.5 mm².

[0008] In some embodiments, the central angle α of the liquid outlet satisfies: 15 degrees ≤ α ≤ 180 degrees.

[0009] In some embodiments, the connecting side defines two liquid outlets, which are a first liquid outlet and a second liquid outlet, wherein the first liquid outlet faces the first narrow side and the second liquid outlet faces the second narrow side.

[0010] In some embodiments, the distance from the injection hole to the first narrow side is greater than the distance from the injection hole to the second narrow side, and the opening area of ​​the first outlet is smaller than the opening area of ​​the second outlet.

[0011] In some embodiments, the opening area S1 of the first liquid outlet and the opening area S2 of the second liquid outlet satisfy: 0.09 <S1 / S2<1。

[0012] In some embodiments, the first outlet is an arc-shaped outlet with a central angle of not less than 15 degrees and not more than 30 degrees; the second outlet is an arc-shaped outlet with a central angle of not less than 15 degrees and not more than 180 degrees.

[0013] In some embodiments, the orthographic projection length of the second outlet on the first long side is c, where 0 ≤ c / b ≤ 0.028.

[0014] In some embodiments, the battery cover assembly further includes a pressure relief mechanism disposed on the cover body and located between the first narrow side and the injection hole, wherein the insulating plate body includes a plurality of support protrusions adjacent to the pressure relief mechanism and adjacent to the first long side and the second long side, the plurality of support protrusions not obstructing the electrolyte flowing out from the first outlet.

[0015] According to one aspect of this disclosure, a battery cell is provided, comprising: a housing having an opening; a battery cover assembly according to the foregoing aspect, which covers the opening; at least one cell assembly disposed within a receiving cavity formed by the battery cover assembly and the housing, wherein two long side surfaces of the cell assembly extend in the same direction as a first long side and a second long side, and two short side surfaces of the cell assembly extend in the same direction as a first narrow side and a second narrow side; and electrolyte filling the receiving cavity through an injection hole.

[0016] In some embodiments, a battery cell includes two cell assemblies arranged along the extension directions of a first narrow side and a second narrow side.

[0017] In some embodiments, the cell assembly is a wound cell assembly, wherein 0 ≤ a / b ≤ 0.025; or, the cell assembly is a laminated cell assembly, wherein 0 ≤ a / b ≤ 0.029.

[0018] According to any of the above embodiments of this disclosure, when the electrolyte is injected through the injection hole of the cover plate body at a certain injection pressure, it will be blocked by the bottom and connecting side and restricted from flowing out from at least one of the above-mentioned outlets. The outflow direction is towards the narrow side of the battery cover plate assembly. This can reduce the impact on the long side of the cell assembly, thereby alleviating the wrinkling phenomenon of the negative electrode sheet caused by the impact of electrolyte and improving the safety of the battery cell.

[0019] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0020] The accompanying drawings exemplify embodiments and form part of the specification, serving together with the textual description to explain exemplary implementations of the embodiments. The illustrated embodiments are for illustrative purposes only and do not limit the scope of the claims. Throughout the drawings, the same reference numerals refer to similar but not necessarily identical elements.

[0021] Figure 1 This is a schematic diagram of the disassembled structure of a single battery cell in related technologies;

[0022] Figure 2A This is a schematic diagram of the cross-sectional structure of a wound battery cell assembly in related technologies;

[0023] Figure 2B This is a schematic diagram of the disassembled structure of a laminated battery cell assembly in related technologies;

[0024] Figure 3 This is a simulation diagram of electrolyte flow during injection into a battery cell in related technologies.

[0025] Figure 4 An image showing the wrinkles observed after unfolding multiple negative electrode sheets removed from a wound cell assembly of a battery cell in a related technology;

[0026] Figure 5 This is a schematic diagram of the longitudinal cross-sectional structure of a battery cell according to some embodiments of this disclosure;

[0027] Figure 6A This is a schematic diagram of the inner structure of a battery cover assembly according to some embodiments of the present disclosure;

[0028] Figure 6B For some embodiments of the present disclosure, the battery cover assembly is in Figure 6A An enlarged structural diagram at point A;

[0029] Figure 7This is a simulation diagram illustrating the flow of electrolyte within a single battery cell after the battery cover assembly design according to the embodiments of this disclosure.

[0030] Figure 8 An image showing the appearance of multiple negative electrode sheets after being unfolded from a wound cell assembly of a battery cell according to some embodiments of the present disclosure;

[0031] Figure 9 This is a top view of a battery cell after the battery cover assembly has been removed, according to some embodiments of this disclosure.

[0032] Related technical figure labels:

[0033] 001-Battery cell; 010-Cell assembly; 0101-Long side; 0102-Short side;

[0034] 030-Battery cover assembly; 050-Housing casing; 011-Positive electrode plate; 0110-Positive current collector;

[0035] 0111 - Positive electrode active material layer; 12 - Negative electrode sheet; 0120 - Negative electrode current collector;

[0036] 0121 - Negative electrode active material layer; 012a - Planar portion; 012b - Curved portion; 013 - Separator;

[0037] 014 - Positive electrode tab; 015 - Negative electrode tab; 041 - Positive electrode terminal; 042 - Negative electrode terminal;

[0038] 0315 - Injection hole; 0316 - Sealing part; 016 - Wrinkle.

[0039] Reference numerals in the accompanying drawings of the embodiments disclosed herein:

[0040] 100 - Battery cell; 10 - Cell assembly; 10a - First part; 10b - Second part; 12 - Negative electrode sheet;

[0041] 101 - Long side; 102 - Short side; 30 - Battery cover assembly; 50 - Housing; 310 - Cover body;

[0042] 311 - First narrow side; 312 - Second narrow side; 313 - First long side; 314 - Second long side; 315 - Injection hole;

[0043] 316 - Sealing component; 320 - Insulating board; 321 - Main body of insulating board; 322 - Bottom of shield; 323 - Connecting side;

[0044] 324 - Liquid outlet; 3241 - First liquid outlet; 3242 - Second liquid outlet; 330 - Pressure relief mechanism;

[0045] 21-Supporting protrusion; 341-First electrode terminal; 342-Second electrode terminal; 501-Insulating spacer structure. Detailed Implementation

[0046] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0047] In this disclosure, unless otherwise stated, the use of terms such as "first," "second," etc., to describe various elements is not intended to limit the positional, temporal, or importance relationships of these elements; such terms are merely used to distinguish one element from another. In some examples, the first element and the second element may refer to the same instance of that element, while in other cases, based on the context, they may refer to different instances.

[0048] The terminology used in the description of the various examples in this disclosure is for the purpose of describing particular examples only and is not intended to be limiting. Unless the context explicitly indicates otherwise, an element may be one or more unless the number of elements is specifically limited. Furthermore, the term "and / or" as used in this disclosure covers any one of the listed items and all possible combinations thereof.

[0049] A single battery cell is the smallest unit in a battery that provides the energy source. For example... Figure 1 As shown, in the related technology, the battery cell 001 mainly includes a housing 050 and a battery cover assembly 030 that enclose a receiving cavity, a cell assembly 010 disposed within the receiving cavity, and electrolyte (not shown in the figure) filled into the receiving cavity through an injection hole 0315 on the battery cover assembly 030. In this related technology, the cell assembly 010 has two long side surfaces 0101 and two short side surfaces 0102, wherein the two long side surfaces 0101 are generally planar, and the two short side surfaces 0102 may be generally planar or curved as shown in the figure.

[0050] like Figure 2A and Figure 2B As shown, the battery cell assembly 010 mainly includes a wound (e.g., Figure 2A (as shown) or stacked type (such as) Figure 2BAs shown, a positive electrode 011, a negative electrode 012, and a separator 013 are assembled together, along with a Mylar coating (not shown) for insulating and protecting the cell assembly 010. The positive electrode 011 includes a positive current collector 0110 and a positive active material layer 0111 (in... Figure 2A (Not shown in the image), a positive electrode active material layer 0111 is coated on the surface of the positive electrode current collector 0110. The positive electrode current collector 0110 without the positive electrode active material layer 0111 is stacked to form the positive electrode tab 014, which is used to connect with... Figure 1 The positive terminal 041, located on the battery cover assembly 030, is electrically connected. The negative electrode plate 012 includes a negative current collector 0120 and a negative active material layer 0121 (in... Figure 2A (Not shown in the image), a negative electrode active material layer 0121 is coated on the surface of the negative electrode current collector 0120. The negative electrode current collector 0120 without the negative electrode active material layer 0121 is stacked to form the negative electrode tab 012, which is used to connect with... Figure 1 The negative terminal 042, located on the battery cover assembly 030, is electrically connected. Taking a lithium-ion battery as an example, the positive electrode current collector 0110 can be made of aluminum, the positive electrode active material layer 0111 can be made of lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc., the negative electrode current collector 0120 can be made of copper, and the negative electrode active material layer 0121 can be made of carbon or silicon, etc. The separator 013 can be made of PP (polypropylene) or PE (polyethylene), etc.

[0051] refer to Figure 1 As shown, during the manufacturing of the battery cell 001, the cell assembly 010 is first placed inside the housing 050, and then the battery cover assembly 030 is closed to the housing 050. Then, the electrolyte is injected into the cavity formed by the battery cover assembly 030 and the housing 050 through the injection hole 0315 on the battery cover assembly 030. Finally, the injection hole 0315 on the battery cover assembly 030 is sealed using the sealing member 0316.

[0052] Because the electrolyte needs to meet a certain injection pressure when injected into the receiving cavity through the injection hole 0315, it will have a certain impact on the cell assembly 010. For example Figure 3 As shown, this is a flow simulation diagram of electrolyte injection into a battery cell in related technologies. It can be seen that the main impact area of ​​the electrolyte after entering the battery cell is the long side surface 0101 of the cell assembly, which easily leads to wrinkles on the negative electrode sheet of the cell assembly due to impact. Figure 4As shown, this is an image of multiple negative electrode sheets removed from a wound cell assembly of a battery cell of the relevant technology, after being unfolded and observed to have wrinkles. It can be seen that after unfolding, the negative electrode sheet 012 presents alternating planar portions 012a and curved portions 012b. Among them, wrinkles 016 mainly occur in the planar portion 012a, which has a larger area ratio. This corresponds to the main impact area of ​​the electrolyte described above. The curved portion 012b, due to the winding tension in the winding state, is also more tightly bonded to other layers in the winding process. Therefore, it is less prone to wrinkles than the planar portion 012a.

[0053] In some related technologies, the battery cells use stacked cell modules, which also have similar technical problems. This is because, for the negative electrode sheet of the stacked cell module, the part near the short side is easier to bond tightly with other layers in the stacking process, so it is less prone to wrinkles. However, the part far from the short side has a larger area and more room for deformation, so it is more susceptible to wrinkles caused by electrolyte impact.

[0054] During charging, metal ions are extracted from the positive electrode active material layer of the positive electrode and embedded in the negative electrode active material layer of the negative electrode. In this process, the volume of the negative electrode changes, and wrinkles on the negative electrode may lead to the deposition of elemental metal. Taking a lithium-ion battery cell as an example, wrinkles on the negative electrode may result in insufficient space for lithium intercalation in the negative electrode active material layer, or increased resistance to lithium ion embedding. Consequently, the extracted lithium ions cannot be intercalated into the negative electrode active material layer in equal quantities, resulting in these lithium ions gaining electrons only on the surface of the negative electrode to form elemental lithium metal, i.e., lithium plating. Lithium plating not only degrades battery cell performance and significantly shortens cycle life but also limits the fast-charging capacity of the battery cell. Furthermore, the deposited lithium metal is highly reactive and can react with the electrolyte at relatively low temperatures, causing a decrease in the self-heating initiation temperature and an increase in the self-heating rate of the battery cell, thus seriously jeopardizing the safety of the battery cell.

[0055] Therefore, how to alleviate the wrinkling phenomenon of the negative electrode sheet inside the battery cell and thus improve the safety of the battery cell is a technical problem that urgently needs to be solved by those skilled in the art.

[0056] In view of this, embodiments of the present disclosure provide a battery cover assembly and a battery cell to alleviate the wrinkling phenomenon of the negative electrode sheet inside the battery cell, thereby improving the safety of the battery cell. Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings.

[0057] like Figure 5 , Figure 6A and Figure 6B As shown, where, Figure 5This is a schematic diagram of the longitudinal cross-sectional structure of a battery cell 100 according to some embodiments of this disclosure. Figure 6A This is a schematic diagram of the inner structure of the battery cover assembly 30 according to some embodiments of this disclosure. Figure 6B For some embodiments of the present disclosure, the battery cover assembly 30 is in Figure 6A An enlarged structural schematic diagram at point A. Some embodiments of this disclosure provide a battery cell 100, whose main structure includes: a housing 50 with an opening; a battery cover assembly 30 covering the opening; at least one cell assembly 10 (shown as one in the figure) disposed within a receiving cavity formed by the battery cover assembly 30 and the housing 50; and electrolyte (not shown in the figure) filled into the receiving cavity through an injection hole 315 on the battery cover assembly 30.

[0058] In this embodiment, the housing 50 may be generally cuboid or flat, and correspondingly, the battery cover assembly 30 may be generally rectangular or elongated. The battery cover assembly 30 has opposing first narrow sides 311 and second narrow sides 312, and opposing first long sides 313 and second long sides 314. In this embodiment, the shape of the housing 50 is not strictly limited to a standard cuboid shape, and the shape of the battery cover assembly 30 is not strictly limited to a standard rectangular shape. For example, the battery cover assembly 30 may be generally rounded rectangular, or the two narrow sides of the battery cover assembly 30 may be generally semi-circular, etc.

[0059] In this embodiment, the cell assembly 10 can be a wound cell assembly or a stacked cell assembly, and its basic structure can be referred to the foregoing. Figure 2A and Figure 2B This will not be repeated here.

[0060] In the embodiments disclosed herein, such as Figure 5 As shown, the battery cell assembly 10 includes two end faces (i.e., the upper end face and the lower end face in the figure), two long side faces 101 connected between the two end faces (one of the long side faces 101 facing the reader is shown in the figure), and two short side faces 102. The positive and negative electrode tabs (not shown in the figure) of the battery cell assembly 10 are provided on the end faces; for example, they can both be provided on the upper end face of the battery cell assembly 10. The two long side faces 101 of the battery cell assembly 10 extend in the same direction as the first long side 313 and the second long side 314 of the battery cover assembly 30. The two short side faces 102 of the battery cell assembly 10 extend in the same direction as the first narrow side 311 and the second narrow side 312 of the battery cover assembly 30, that is, they correspond one-to-one with the two short side walls of the housing 50. In this embodiment, the two long side faces 101 of the battery cell assembly 10 are generally planar, and the two short side faces 102 of the battery cell assembly 10 can be generally planar or curved.

[0061] like Figure 5 , Figure 6A and Figure 6B As shown, some embodiments of this disclosure provide a battery cover assembly 30 applied to a battery cell 100 for covering the housing 50 of the battery cell 100. The battery cover assembly 30 includes a cover body 310 and an insulating plate 320. In these embodiments, the cover body 310 has opposing first narrow sides 311 and second narrow sides 312, and opposing first long sides 313 and second long sides 314, and the cover body 310 has an injection hole 315.

[0062] The insulating plate 320 includes an insulating plate body 321, a shielding bottom 322, and a connecting side 323. The insulating plate body 321 is located inside the cover plate body 310. The shielding bottom 322 is located on the side of the insulating plate body 321 facing away from the cover plate body 310, and the orthographic projection of the shielding bottom 322 on the cover plate body 310 at least partially coincides with the injection hole 315. The connecting side 323 connects the shielding bottom 322 and the insulating plate body 321. One end of the connecting side 323 is connected to the shielding bottom 322, and the other end is connected to the insulating plate body 321. The connecting side 323 defines at least one liquid outlet 324 (e.g., ...). Figure 6A and Figure 6B The first liquid outlet 3241 and the second liquid outlet 3242 are provided. For any liquid outlet 324, its liquid outlet direction is towards the first narrow side 311 or the second narrow side 312. For any liquid outlet 324, its orthographic projection length on the first long side 313 is a, and the length of the first long side 313 is b. Where a and b satisfy: 0≤a / b≤0.03.

[0063] In this embodiment, the cover body 310 may be generally rectangular or elongated, and its two narrow sides may be straight or semi-circular, respectively. The material of the cover body 310 is not limited; for example, it may be made of a metal material (such as aluminum alloy) with a certain hardness and strength. The housing 50 may be generally cuboid or flat, and its material is not limited; for example, it may include at least one of copper, iron, aluminum, stainless steel, aluminum alloy, and plastic. In some embodiments, the battery cover assembly 30 may include a sealing member 316 for sealing the injection hole 315. This sealing member 316 may be, for example, a plastic sealing member, a rubber sealing member, or a metal sealing member, etc., and this disclosure does not specifically limit its application.

[0064] In this embodiment, the battery cover assembly 30 may be provided with functional components such as electrode terminals (e.g., positive and negative terminals) and a pressure relief mechanism 330 (e.g., an explosion-proof valve). The electrode terminals are used for electrical connection with the cell assembly 10 to output or input electrical energy to the battery cell 100. The pressure relief mechanism 330 can release internal pressure when the internal pressure of the battery cell 100 reaches a pressure threshold to provide safety protection. In this embodiment, the insulating plate 320 may be, for example, a plastic insulating plate or a rubber insulating plate, and its main function is to insulate and isolate the electrical components inside the housing 50 from the battery cover assembly 30, thereby reducing the risk of short circuit. In some embodiments, the insulating plate 320 may be thermally fused to the Mylar coating of the cell assembly 10.

[0065] In related technologies, the main impact area of ​​the electrolyte after entering the battery cell through the injection hole is the long side of the cell assembly. As described above, this can easily cause wrinkles to form on the negative electrode sheet in this area.

[0066] This embodiment modifies the structure of the battery cover assembly 30 by designing a shielding bottom 322 and a connecting side 323 at a position approximately opposite to the electrolyte injection hole 315. The connecting side 323 defines at least one electrolyte outlet 324. For any electrolyte outlet 324, its discharge direction (which can be understood as the central axis of the electrolyte outlet 324, i.e., the main direction in which the electrolyte flows out of the electrolyte outlet 324) is towards the first narrow side 311 or the second narrow side 312. Thus, when the electrolyte passes through the electrolyte injection hole 315 of the cover body 310 at a certain injection pressure, it is restricted by the shielding bottom 322 and the connecting side 323 to flow out from the at least one electrolyte outlet 324, and the discharge direction is towards the narrow side of the battery cover assembly 30. Compared with related technologies, this can reduce the impact on the long side 101 of the cell assembly 10, thereby alleviating the wrinkling phenomenon of the negative electrode sheet caused by the impact of electrolyte and improving the safety of the battery cell 100.

[0067] In the embodiments of this disclosure, for any outlet 324, the projected length a of its first long side 313 and the length b of the first long side 313 satisfy: 0 ≤ a / b ≤ 0.03. For example, a / b can be designed as 0, 0.01, 0.015, 0.02, 0.025, 0.028, 0.029, or 0.03, etc., and is not limited to these ratios. The design of these embodiments ensures that the electrolyte flows substantially towards the narrow side of the battery cover assembly 30 when it flows out of the outlet 324.

[0068] It should be noted that, depending on the specific design of the battery cell 100 and the different injection pressures of the electrolyte, after the electrolyte flows out of the outlet 324, it may reach the vicinity of the narrow side of the battery cover assembly 30 along the outlet direction, or it may reach the vicinity of the narrow side of the battery cover assembly 30 along a direction at a certain angle to the outlet direction due to gravity or other factors. Some electrolyte may not reach the vicinity of the narrow side of the battery cover assembly 30. However, compared with related technologies, more electrolyte is guided to the vicinity of the narrow side of the battery cover assembly 30, thus reducing the impact on the long side 101 of the cell assembly 10.

[0069] In this embodiment of the disclosure, the orthographic projection of the shielding bottom 322 of the insulating plate 320 onto the cover plate body 310 can partially or completely overlap with the injection hole 315, and the area of ​​the shielding bottom 322 can be greater than or equal to the area of ​​the injection hole 315. This has a certain limiting and guiding effect on the electrolyte after passing through the injection hole 315. This embodiment of the disclosure does not make specific limitations on this.

[0070] like Figure 7 As shown, it is a simulation diagram of the electrolyte flow when injected into a single battery cell after adopting the design of the battery cover assembly 30 of the aforementioned embodiment of this disclosure. Figure 3 As can be seen, after adopting the design of the present disclosure embodiment, more electrolyte can be guided to the vicinity of the short side 102 of the cell assembly near the injection hole 315, thereby reducing the impact on the long side 101 of the cell assembly.

[0071] like Figure 8 As shown, it is an image of the appearance of multiple negative electrode sheets 12 after being unfolded from a wound cell assembly of a battery cell in some embodiments of this disclosure, in comparison with... Figure 4 It can be seen that after adopting the design of the embodiments disclosed herein, the wrinkles of the negative electrode sheet 12 are significantly reduced, which is beneficial to improving the safety of the battery cell.

[0072] In some embodiments of this disclosure, the values ​​of a and b mentioned above can be taken within the following ranges: 0.6 mm ≤ a ≤ 4.5 mm, 148 mm ≤ b ≤ 206 mm. These embodiments are designed so that the electrolyte flows substantially towards the narrow edge of the battery cover assembly 30 when exiting from the outlet 324.

[0073] In some embodiments, 'a' can be 0.6 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, 2.8 mm, 3 mm, 3.6 mm, 4.2 mm, or 4.5 mm, and is not limited to these values.

[0074] In some embodiments, b can be 148 mm, 150 mm, 155 mm, 160 mm, 170 mm, 174 mm, 175 mm, 180 mm, 195 mm, 200 mm, or 206 mm, etc., and is not limited to these values.

[0075] In some embodiments of this disclosure, the opening area S of the outlet 324 (illustrated in the figure) can be understood as the area of ​​the geometric surface enclosed by the edge of the outlet 324, and can be taken from the following range: 16.5 mm² ≤ S ≤ 28.5 mm². For example, S can be 16.5 mm², 18 mm², 19.5 mm², 20 mm², 21 mm², 22.5 mm², 24 mm², 25.5 mm², 26 mm², 27 mm², or 28.5 mm², etc., and is not limited to these values. The size of the opening area of ​​the outlet 324 affects the flow rate and flow volume of the electrolyte out of the outlet 324. The design of these embodiments allows the electrolyte to flow out of the outlet 324 at an appropriate flow rate and flow volume, thereby helping to reduce the impact on the long side 101 of the battery cell assembly 10.

[0076] In some embodiments of this disclosure, the central angle α of the outlet 324 can be understood as the angle formed by the lines connecting the two ends of the orthographic projection of the outlet 324 on the cover body 310 and the center of the orthographic projection of the bottom shield 322 on the cover body 310. The central angle α can be taken within the following range: 15 degrees ≤ α ≤ 180 degrees. For example, α can be 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees, 80 degrees, 90 degrees, 100 degrees, 120 degrees, 135 degrees, 155 degrees, 175 degrees, or 180 degrees, etc., and is not limited to these values. The size of the central angle of the outlet 324 affects the flow rate and direction of the electrolyte flowing out of the outlet 324. The design of these embodiments allows the electrolyte to flow out of the outlet 324 at an appropriate flow rate and direction, thereby helping to reduce the impact on the long side 101 of the battery cell assembly 10.

[0077] In this publicly disclosed implementation, the specific number of outlets 324 is not limited. For example... Figure 6A and Figure 6B As shown, in some embodiments of this disclosure, the connecting side 323 can define two liquid outlets 324, namely a first liquid outlet 3241 and a second liquid outlet 3242, wherein the first liquid outlet 3241 faces the first narrow side 311, and the second liquid outlet 3242 faces the second narrow side 312. The design of the battery cover assembly 30 in this embodiment can guide the electrolyte as far as possible towards the two narrow sides of the battery cover assembly 30, thereby reducing the impact on the long side 101 of the cell assembly 10 and alleviating the wrinkling phenomenon of the negative electrode sheet caused by the impact of the electrolyte.

[0078] Combined with Figure 5 and Figure 6A As shown, in some embodiments of the present disclosure, the distance L1 from the liquid injection hole 315 to the first narrow side 311 is greater than the distance L2 from the liquid injection hole 315 to the second narrow side 312, and the opening area of the first liquid outlet 3241 is smaller than the opening area of the second liquid outlet 3242.

[0079] The opening area of the liquid outlet 324 is the key to determining the flow rate of the electrolyte flowing out therefrom. As Figure 5 shown, the cell assembly 10 can be roughly divided into a first part 10a and a second part 10b based on the position of the liquid injection hole 315. Obviously, in these embodiments, the proportion of the first part 10a is larger. Therefore, the negative electrode sheet of the first part 10a has a larger deformation space and is more likely to be affected by the electrolyte impact and wrinkle. For this reason, in these embodiments of the present disclosure, the opening area of the first liquid outlet 3241 is designed to be smaller than the opening area of the second liquid outlet 3242, so that more electrolyte can flow in the direction of the second narrow side 312, thereby minimizing the impact of the electrolyte on the negative electrode sheet of the first part 10a and alleviating the wrinkling phenomenon.

[0080] In some embodiments of the present disclosure, the ratio of the opening area S1 of the first liquid outlet 3241 to the opening area S2 of the second liquid outlet 3242 is designed to satisfy: 0.09 < S1 / S2 < 1. By precisely controlling the ratio of the opening areas of the first liquid outlet 3241 and the second liquid outlet 3242, the wrinkling phenomenon can be more effectively alleviated.

[0081] In the embodiments of the present disclosure, the specific structural shape of the shielding bottom 322 and the connecting side 323 is not limited. For example, the shielding bottom 322 and the connecting side 323 can be in a thin-walled shape, and the shielding bottom 322 can be roughly circular, oval, rectangular, square, etc.

[0082] In the embodiments of the present disclosure, the specific shapes of the first liquid outlet 3241 and the second liquid outlet 3242 are not limited. For example, they can be designed as rectangular liquid outlets, circular liquid outlets, trapezoidal liquid outlets, etc.

[0083] As Figure 6BAs shown, in some embodiments, the first liquid outlet 3241 and the second liquid outlet 3242 can be designed as arc-shaped liquid outlets, that is, the outlet surfaces are arc-shaped curved surfaces. Provided that the opening area of ​​the first liquid outlet 3241 is smaller than the opening area of ​​the second liquid outlet 3242, the central angle α1 of the first liquid outlet 3241 can be within a range of not less than 15 degrees and not more than 30 degrees, and the central angle α2 of the second liquid outlet 3242 can be within a range of not less than 15 degrees and not more than 180 degrees. In these embodiments, the shielding bottom 322 can be a circular or elliptical shielding bottom wall, and the connecting side 323 can be a curved shielding side wall. The integrally connected insulating board body 321, shielding bottom 322, and connecting side 323 can be formed by injection molding, which is simple to manufacture and has a low manufacturing cost.

[0084] In some embodiments of this disclosure, such as Figure 6A As shown, the orthogonal projection length of the second outlet 3242 on the first long side 313 is c, where 0 ≤ c / b ≤ 0.028. This design can minimize the impact of the electrolyte on the long side 101 of the cell assembly 10, thereby alleviating the wrinkling phenomenon of the negative electrode sheet.

[0085] like Figure 5 and Figure 6A As shown, in some embodiments of this disclosure, the battery cover assembly 30 further includes a pressure relief mechanism 330, which is disposed on the cover body 310 and located between the first narrow side 311 and the injection hole 315. The insulating plate body 321 includes a plurality of support protrusions 21 (two support protrusions 21 are shown in the figure) adjacent to the pressure relief mechanism 330 and adjacent to the first long side 313 and the second long side 314, which do not obstruct the electrolyte flowing out from the first outlet 3241.

[0086] The pressure relief mechanism 330 can open when the internal pressure of the battery cell 100 reaches a pressure threshold, thereby dissipating the high-pressure gas inside the battery cell 100 to the outside and preventing the battery cell 100 from bursting due to pressure accumulation. In some embodiments, the pressure relief mechanism 330 can be an explosion-proof valve or a pressure relief hole, etc. The multiple support protrusions 21 of the insulating plate 320 can provide structural support and protection for the pressure relief mechanism 330. For example, they can keep the pressure relief mechanism 330 in a certain position, maintain a certain distance between the pressure relief mechanism 330 and the cell assembly 10, and reduce the possibility of the pressure relief mechanism 330 being accidentally opened. In the embodiments of this disclosure, the multiple support protrusions 21 do not obstruct the electrolyte flowing out from the first outlet 3241. In this way, the electrolyte can flow as much as possible toward the first narrow side 311, thereby reducing the impact on the long side 101 of the cell assembly 10 and improving the wrinkling phenomenon of the negative electrode sheet. The specific structural form of the support protrusions 21 is not limited. Figure 6AAs shown, the orthographic projections of the two support protrusions 21 on the first narrow side 311 do not overlap with the orthographic projection of the first liquid outlet 3241 on the first narrow side 311, thus not interfering with the flow direction of the electrolyte flowing out of the first liquid outlet 3241. The two support protrusions 21 also allow for a certain distance between the pressure relief mechanism 330 and the cell assembly 10.

[0087] In this embodiment of the disclosure, the insulating plate 320 may have different material thicknesses in different areas. For example, the area of ​​the insulating plate 320 opposite to the pressure relief mechanism 330 may be designed to be thinner than the material thickness of other areas, thereby meeting the structural strength design requirements and facilitating the rapid pressure relief of the battery cell 100.

[0088] like Figure 5 As shown, in some embodiments of this disclosure, the battery cover assembly 30 further includes a first electrode terminal 341 and a second electrode terminal 342, wherein the first electrode terminal 341 is disposed on the cover body 310 and located between the first narrow side 311 and the pressure relief mechanism 330, and the second electrode terminal 342 is disposed on the cover body 310 and located between the liquid injection hole 315 and the second narrow side 312.

[0089] In some embodiments, the first electrode terminal 341 may be a positive electrode post, and the second electrode terminal 342 may be a negative electrode post. In other embodiments, the first electrode terminal 341 may be a negative electrode post, and the second electrode terminal 342 may be a positive electrode post. The positive electrode post is used to electrically connect to the positive electrode tab of the cell assembly 10, for example, through a positive electrode adapter (not shown in the figure), and the negative electrode post is used to electrically connect to the negative electrode tab of the cell assembly 10, for example, through a negative electrode adapter (not shown in the figure). Corresponding through holes may be provided on the cover plate body 310 and the insulating plate 320 corresponding to the first electrode terminal 341 and the second electrode terminal 342. Thus, electrical energy of the battery cell 100 can be output or input to the battery cell 100 through the positive and negative electrode posts.

[0090] refer to Figure 5 As shown, this disclosure also provides a battery cell 100, which includes a housing 50 with an opening, a battery cover assembly 30 according to any of the foregoing embodiments covering the opening, at least one cell assembly 10 (shown as one in the figure) disposed in a receiving cavity formed by the battery cover assembly 30 and the housing 50, and electrolyte filling the receiving cavity through the liquid injection hole 315 of the battery cover assembly 30, wherein the two long side surfaces 101 of the cell assembly 10 extend in the same direction as the first long side 313 and the second long side 314, and the two short side surfaces 102 of the cell assembly 10 extend in the same direction as the first narrow side 311 and the second narrow side 312.

[0091] Based on the design of the battery cover assembly 30 in the aforementioned embodiments, the wrinkling phenomenon caused by the impact of electrolyte on the negative electrode sheet can be alleviated, thereby improving the safety of the battery cell 100.

[0092] In some embodiments, the battery cell assembly 10 can be a wound battery cell assembly, and the aforementioned ratio a / b can be in the range of 0 ≤ a / b ≤ 0.025. Since the laminated structure of the wound battery cell assembly near the short side 102 is relatively dense, the electrolyte is not easily wetted. Therefore, the value of a / b can be made as small as possible so that more electrolyte flows to the vicinity of the short side 102.

[0093] In other embodiments, the core assembly 10 can be a laminated cell assembly, and the aforementioned ratio a / b can be in the range of 0 ≤ a / b ≤ 0.029. Since the laminated structure near the short side 102 of the laminated cell assembly is looser than that of the aforementioned wound cell assembly, the electrolyte is easier to wet. Therefore, the value of a / b can be appropriately larger than that of the aforementioned wound cell assembly.

[0094] Regardless of the form of the cell assembly 10 used, the design of the battery cover assembly 30 in this embodiment of the present disclosure is beneficial to alleviating the wrinkling phenomenon of its negative electrode sheet caused by the impact of electrolyte.

[0095] like Figure 9 The diagram shown is a top view of a battery cell 100 according to some embodiments of this disclosure after the battery cover assembly has been removed. The battery cell 100 includes two cell assemblies 10, which are arranged along the extending directions of a first narrow side and a second narrow side of the battery cover assembly (not shown in the figure). The two cell assemblies 10 are electrically connected and spaced apart from each other by an insulating spacer structure 501.

[0096] Based on the design of the battery cover assembly 30 in the aforementioned embodiments of this disclosure, it is beneficial to alleviate the wrinkling phenomenon of the negative electrode sheet of the two cell assemblies 10 caused by the impact of electrolyte, thereby improving the safety of the battery cell 100.

[0097] This disclosure also provides a battery that may include a housing and multiple battery cells located within the housing, which are combined in series and / or in parallel, wherein each battery cell may employ the design of the foregoing embodiments.

[0098] Batteries can be either power batteries or energy storage batteries. Power batteries are used in applications including, but not limited to, vehicles, ships, aircraft, spacecraft, power tools, electric toys, and various mobile devices. Energy storage batteries are used in applications including, but not limited to, solar power systems, hydropower systems, and wind power systems. Because the wrinkling phenomenon of the negative electrode sheet in the battery cell has been mitigated, the safety of the battery cell has been improved, and therefore, the safety of the entire battery has also been improved accordingly.

[0099] This disclosure also provides an electrical device that includes the battery described in the foregoing embodiments. The electrical device can be any type of electrical device that requires the use of a battery. Because the safety of the battery is improved, the safety of the electrical device is correspondingly improved.

[0100] While embodiments or examples of this disclosure have been described with reference to the accompanying drawings, it should be understood that the methods, systems, and devices described above are merely exemplary embodiments or examples, and the scope of this utility model is not limited by these embodiments or examples, but only by the granted claims and their equivalents. Various elements in the embodiments or examples may be omitted or replaced by their equivalents. Furthermore, the steps may be performed in a different order than that described in this disclosure. Further, various elements in the embodiments or examples may be combined in various ways. Importantly, as technology evolves, many elements described herein can be replaced by equivalents that appear after this disclosure.

Claims

1. A battery cover assembly for sealing with the housing of a battery cell, characterized in that, The battery cover assembly includes: The cover body has opposing first narrow sides and second narrow sides, opposing first long sides and second long sides, and an injection hole; and An insulating plate includes an insulating plate body, a shielding bottom, and a connecting side. The insulating plate body is located inside the cover plate body. The shielding bottom is located on the side of the insulating plate body opposite to the cover plate body, and the orthographic projection of the shielding bottom on the cover plate body at least partially coincides with the injection hole. The connecting side connects the shielding bottom and the insulating plate body. One end of the connecting side is connected to the shielding bottom, and the other end is connected to the insulating plate body. The connecting side defines at least one liquid outlet. The liquid outlet's discharge direction is towards the first narrow side or the second narrow side. The orthographic projection length of the liquid outlet on the first long side is a, and the length of the first long side is b, where 0 ≤ a / b ≤ 0.

03.

2. The battery cover assembly according to claim 1, characterized in that, 0.6 mm ≤ a ≤ 4.5 mm, 148 mm ≤ b ≤ 206 mm.

3. The battery cover assembly according to claim 1, characterized in that, The opening area S of the liquid outlet satisfies: 16.5 square millimeters ≤ S ≤ 28.5 square millimeters.

4. The battery cover assembly according to claim 1, characterized in that, The central angle α of the liquid outlet satisfies: 15 degrees ≤ α ≤ 180 degrees.

5. The battery cover assembly according to claim 1, characterized in that, The connecting side defines two liquid outlets, which are a first liquid outlet and a second liquid outlet, wherein the first liquid outlet faces the first narrow side and the second liquid outlet faces the second narrow side.

6. The battery cover assembly according to claim 5, characterized in that, The distance from the injection hole to the first narrow side is greater than the distance from the injection hole to the second narrow side, and the opening area of ​​the first outlet is smaller than the opening area of ​​the second outlet.

7. The battery cover assembly according to claim 6, characterized in that, The opening area S1 of the first liquid outlet and the opening area S2 of the second liquid outlet satisfy: 0.09 <S1 / S2<1。 8. The battery cover assembly according to claim 6, characterized in that, The first liquid outlet is an arc-shaped liquid outlet with a central angle of not less than 15 degrees and not more than 30 degrees; The second outlet is an arc-shaped outlet with a central angle of not less than 15 degrees and not more than 180 degrees.

9. The battery cover assembly according to claim 6, characterized in that, The orthographic projection length of the second outlet on the first long side is c, where 0 ≤ c / b ≤ 0.

028.

10. The battery cover assembly according to any one of claims 6 to 9, characterized in that, Also includes: A pressure relief mechanism is provided on the cover plate body and located between the first narrow side and the injection hole. The insulating plate body includes a plurality of support protrusions adjacent to the pressure relief mechanism and adjacent to the first long side and the second long side. The plurality of support protrusions do not obstruct the electrolyte flowing out from the first outlet.

11. A single battery cell, characterized in that, include: A shell with an opening; The battery cover assembly according to any one of claims 1 to 10, wherein the battery cover assembly covers the opening; At least one battery cell assembly is disposed within a receiving cavity formed by the battery cover assembly and the housing, wherein the two long side surfaces of the battery cell assembly extend in the same direction as the first long side and the second long side, and the two short side surfaces of the battery cell assembly extend in the same direction as the first narrow side and the second narrow side; and Electrolyte is filled into the receiving cavity through the injection hole.

12. The battery cell according to claim 11, characterized in that, The battery cell includes two cell assemblies, which are arranged along the extending directions of the first narrow side and the second narrow side.

13. The battery cell according to claim 11 or 12, characterized in that, The battery cell assembly is a wound battery cell assembly, wherein 0 ≤ a / b ≤ 0.025; or The battery cell assembly is a stacked battery cell assembly, wherein 0 ≤ a / b ≤ 0.029.

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