Battery, battery module, and battery pack

Abstract

This invention discloses a battery, battery module, and battery pack, relating to the field of battery technology. The battery includes a housing and a cell. The housing has a large surface area, and the cell is disposed within the housing. The cell includes a separator and multiple electrode plates stacked on top of each other. The stacking direction of the electrode plates faces the large surface area of ​​the housing. The separator includes at least an outer layer extending to the outermost electrode plate, covering the side of the outermost electrode plate facing the large surface area of ​​the housing, thus separating the electrode plates from the housing. Furthermore, the minimum vertical distance h between the housing and the outer layer in the area of ​​the large surface area of ​​the housing is within a preset range. This battery, by adjusting the distance between the electrode plates of the cell and the housing, maintains the cell and housing at a suitable interval, thereby preventing foreign objects attached inside the housing from piercing the separator, causing the cell to overlap with the housing, and thus causing a short circuit. This battery module and battery pack utilize the above-described battery and possess the beneficial effects of the battery described above.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery, battery module, and battery pack. Background Art

[0002] A stacked battery is a type of lithium-ion battery that assembles a positive electrode, a separator, and a negative electrode in sequence to form a multi-layered cell. Compared to traditional wound batteries, stacked batteries have higher space utilization and more uniform current distribution, making them suitable for high-energy-density and high-power applications such as electric vehicles and energy storage systems.

[0003] The separator plays a crucial role in stacked batteries. During the assembly process, the separator is typically placed between the positive and negative electrodes to prevent direct contact and short circuits. However, during the manufacturing process, foreign objects such as metal particles and dust may be introduced and adhere to the inside of the battery casing. When the cells are assembled into the battery casing, these foreign objects may puncture the separator, causing direct contact between the positive and negative electrodes, leading to an internal short circuit or even thermal runaway. Summary of the Invention

[0004] The purpose of this invention is to provide a battery, battery module, and battery pack that, by adjusting the spacing between the electrode plates and the battery casing, prevents foreign objects attached to the inside of the battery casing from piercing the separator and causing a short circuit in the battery.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A battery comprising:

[0007] The shell, having a large shell surface;

[0008] A battery cell is disposed within the housing, wherein the battery cell includes a separator and a plurality of electrode plates, wherein the plurality of electrode plates are stacked to form a discontinuous stacked structure, and the stacking direction of the plurality of electrode plates faces the large surface of the housing; the separator is disposed between two adjacent electrode plates, and the separator extends at least to the side of the outermost electrode plate facing the large surface of the housing, to separate the electrode plates from the housing; and,

[0009] The minimum vertical distance between the outermost electrode sheet facing the large surface of the housing and the large surface of the housing facing the battery cell is h, and 0.05mm≤h≤5mm.

[0010] Based on the aforementioned battery, this application also provides a battery module comprising at least two of the aforementioned batteries, wherein the two batteries are electrically connected by being connected in series or in parallel.

[0011] Based on the above-mentioned battery module, this application also provides a battery pack, which includes a housing and at least two of the aforementioned battery modules, wherein the two battery modules are disposed within the housing and are electrically connected.

[0012] Compared with the prior art, the battery, battery module, and battery pack of this invention have the following advantages:

[0013] This battery maintains a suitable distance between the cell and the casing by adjusting the spacing between the electrode plates of the cell. This prevents the cell's separator from adhering to the inside of the casing after the cell is placed inside, thus preventing foreign objects such as metal particles and dust from puncturing the separator and causing the cell to contact the casing, leading to a short circuit. Furthermore, maintaining a suitable distance between the cell and the casing allows the cell to fully utilize the internal space of the casing, ensuring efficient use of that space. This battery module and battery pack utilize the aforementioned battery and possess the beneficial effects described above. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the battery in an embodiment of the present invention;

[0015] Figure 2 This is a front view of the battery in an embodiment of the present invention;

[0016] Figure 3 yes Figure 2 Cross-sectional view of AA in the middle;

[0017] Figure 4 yes Figure 3 Enlarged view of B in the middle;

[0018] Figure 5 yes Figure 3 Enlarged view of C;

[0019] Figure 6 This is a schematic diagram illustrating the interaction between the insulating film and the battery cell in an embodiment of the present invention;

[0020] Figure 7 This is a schematic diagram of a battery casing with two battery cells arranged inside, according to an embodiment of the present invention.

[0021] Figure 8 This is a schematic diagram of the connection between the battery cell and the electrode in an embodiment of the present invention.

[0022] In the diagram, 100 is the battery; 1 is the casing; 1a is the main surface of the casing; 2 is the battery cell; 2a is the separator; 2a1 is the outer layer; 2a2 is the inner layer; 2a3 is the outer layer; 2b is the electrode plate; 2b1 is the positive electrode plate; 2b2 is the negative electrode plate; 2c is the main surface of the battery cell; 2d is the first end; 2e is the second end; 3 is the insulating film; 4 is the tab; and 5 is the cover plate. Detailed Implementation

[0023] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0024] In the description of this invention, it should be understood that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on or indirectly on that other element. When an element is referred to as being "connected to" another element, it can be directly connected to or indirectly connected to that other element. The terms "mounted," "connected," and "attached" should be interpreted broadly, for example, referring to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two elements or an interaction between two elements. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] In the description of this invention, it should be understood that the terms "height," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used in this invention to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0026] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0027] Example

[0028] refer to Figure 1-8This embodiment provides a battery 100, including a housing 1, a cover plate 5, and a battery cell 2. The housing 1 has a large housing surface 1a, and the cover plate 5 is connected to the housing 1, isolating the internal space of the housing 1 from the external environment. The battery cell 2 is disposed inside the housing 1 and includes a separator 2a and multiple electrode plates 2b. The multiple electrode plates 2b are stacked to form a discontinuous stacked structure, and the stacking direction of the multiple electrode plates 2b faces the large housing surface 1a. The separator 2a is disposed between two adjacent electrode plates 2b and extends at least to the side of the outermost electrode plate 2b facing the large housing surface 1a to form an outer layer 2a1. The outer layer 2a1 covers the side of the outermost electrode plate 2b facing the large housing surface 1a to separate the electrode plate 2b from the housing 1 and forms the large cell surface 2c.

[0029] It should be noted that the battery 100 in this embodiment is a stacked battery 100. A stacked battery is a battery structure assembled by stacking multiple electrode sheets. It alternately stacks positive electrode, negative electrode and separator into a multi-layer structure. The positive electrode sheet is usually a metal foil (usually aluminum foil) coated with positive electrode active material (such as ternary lithium, lithium iron phosphate, etc.), the negative electrode sheet is usually a metal foil (usually copper foil) coated with negative electrode active material (such as graphite, silicon-based material, etc.), and the separator is an insulating film located between the positive and negative electrodes to prevent short circuits while allowing lithium ions to pass through.

[0030] It should be noted that the housing 1 is used to encapsulate the battery cell 2 and other components such as the electrolyte. The housing 1 can be of various shapes and sizes, such as cuboid or hexagonal prism, and its shape can be determined according to the specific shape and size of the battery cell 2. The housing 1 can be made of various materials, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0031] It should be noted that the large surface 1a of the casing is the largest surface in the casing 1 of the battery 100. The large surface 1a is usually the main load-bearing part of the casing 1, affecting the overall structural strength of the casing 1. In addition, it is usually the main area for heat dissipation of the casing 1, affecting the heat dissipation efficiency of the battery 100.

[0032] It should be noted that the large side surface 2c of the battery cell refers to the larger side surface of the battery cell 2. It is usually the part of the battery cell 2 with the largest area when the electrode sheet 2b and the separator 2a are stacked. Furthermore, the large side surface 2c of the battery cell is usually perpendicular to the stacking direction of the electrode sheet 2b.

[0033] Understandably, the electrode plate 2b of the battery 100 typically includes two types of electrodes with opposite polarities: a positive electrode 2b1 serving as the second electrode and a negative electrode 2b2 serving as the first electrode. The electrode assembly of the battery 100 operates by the movement of metal ions between the positive electrode 2b1 and the negative electrode 2b2. The cell's cycling process involves metal ions moving from the positive electrode 2b1 to the negative electrode 2b2, and then from the negative electrode 2b2 back to the positive electrode 2b1. (Reference) Figure 3 In the battery cell 2 of this embodiment, the positive electrode 2b1 and the negative electrode 2b2 are stacked alternately in sequence, that is, the positive electrode 2b1 and the negative electrode 2b2 are stacked in the order of negative electrode 2b2-positive electrode 2b1-negative electrode 2b2-positive electrode 2b1-negative electrode 2b2, thereby forming a discontinuous stacked structure, and the negative electrode 2b2 is located in the outermost layer of the stacked structure, that is, the side facing the large surface 1a of the shell.

[0034] It should be noted that the battery cell 2 in this embodiment is a stacked battery cell, with multiple electrode plates 2b stacked to form a discontinuous stacked structure, which means that any two adjacent positive electrode plates 2b1 are discontinuous and / or any two adjacent negative electrode plates 2b2 are discontinuous.

[0035] During the manufacturing process of battery 100, because the electrode sheet 2b has a discontinuous structure, it needs to be cut to form individual electrode sheets before being stacked to form cell 2. The cut parts of the electrode sheet 2b are the weakest parts of the electrode sheet. During the use of battery 100, the corners and cut parts of the electrode sheet 2b are prone to pressure and material loss, which can puncture the separator 2a and cause a short circuit between cell 2 and casing 1. At the same time, during the use of battery 100, the large surface 2c of the cell is prone to expansion, which also increases the risk of short circuit between cell 2 and casing 1. Therefore, in this embodiment, battery 100 adjusts the spacing between the electrode sheet 2b and casing 1 so that the minimum vertical spacing between the side of the outermost electrode sheet 2b facing the large surface 1a of casing and the side of the large surface 1a of casing facing cell 2 is h, and 0.05mm≤h≤5mm.

[0036] For example, the minimum vertical distance h between the outermost electrode sheet 2b facing the large surface 1a of the housing and the large surface 1a of the housing facing the cell 2 can be one of the following sizes: 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm.

[0037] By adjusting the distance between the electrode plate 2b of the battery cell 2 and the casing 1, the battery cell 2 and the casing 1 are kept at a suitable distance. In this way, when the battery cell 2 is placed into the casing 1, the separator 2a of the battery cell 2 will not stick to the inside of the casing 1, thereby preventing foreign objects such as metal particles and dust attached to the inside of the casing 1 from piercing the separator 2a, causing the battery cell 2 to overlap with the casing 1, and thus causing a short circuit in the battery 100. Moreover, by keeping the battery cell 2 and the casing 1 at a suitable distance, the battery cell 2 can make full use of the internal space of the casing 1, ensuring the utilization rate of the internal space of the casing 1.

[0038] To verify that the minimum vertical spacing h of the battery 100 provided in this embodiment meets the above-mentioned range, and that the battery 100 of this embodiment can guarantee good insulation performance compared with other batteries 100, 10 sets of tests were conducted in this embodiment, as shown in Table 1 below:

[0039] In Table 1, Test Examples 1 to 10 are based on the battery 100 structure of this embodiment, meaning that the minimum vertical spacing h of the batteries 100 in Test Examples 1 to 10 meets the above-mentioned range. Comparative Examples 1 to 2 are other battery structures, meaning that their minimum vertical spacing h does not meet the above-mentioned range.

[0040] Insulation performance test method: According to Table 1, the battery cells and casings were assembled at different heights h, and the cover plate was welded to the casing using laser welding technology. After completing the liquid injection and formation processes, battery samples with consistent dimensions were obtained; the positive electrode material of the battery was lithium iron phosphate. First, the battery was charged to 3.25V at 1 / 3C current, allowed to stand for 10 minutes, and then discharged to 2.5V at 1 / 3C current, allowed to stand for 1 hour. The open-circuit voltage of the battery was measured and recorded at this time, marked as V1. Subsequently, the above charging and discharging process was repeated, and after standing for 10 minutes, 500 cycles were performed. After the cycle was completed, the battery was allowed to stand for 50 minutes, and the open-circuit voltage of the battery was measured and recorded again, marked as V2. The voltage difference of the battery after the cycle was calculated according to the formula ΔV = V1 - V2. The larger the voltage difference, the worse the insulation performance of the battery cell; conversely, the smaller the voltage difference, the better the insulation performance of the battery cell.

[0041] Discharge capacity test method: Based on the assembly requirements for different heights h in Table 1, the battery cell and casing are assembled, and the cover plate is welded to the casing using laser welding technology. After completing the electrolyte injection and formation steps, battery samples of the same size are obtained; the positive electrode material is also lithium iron phosphate. First, the battery is charged to 3.25V at 1 / 3C current, allowed to stand for 10 minutes, and then discharged to 2.5V at 1 / 3C current, allowed to stand for 10 minutes. Next, it is charged again to 3.25V at 1 / 3C current, allowed to stand for 10 minutes, and then discharged to 2.5V using a constant current of 10A. The discharge time is recorded and marked as T hours. The discharge capacity of the battery is calculated using the formula C = 10 × T. If the calculated capacity is less than 100Ah, the battery sample is deemed unqualified.

[0042] Table 1

[0043]

[0044] As shown in Table 1, when the minimum vertical distance h between the outermost electrode 2b facing the large surface 1a of the casing and the side of the large surface 1a facing the cell 2 meets the above-mentioned range, the voltage drop of the battery 100 is small, the insulation performance is good, and the discharge capacity of the battery 100 is good. However, when the minimum vertical distance h between the outermost electrode 2b facing the large surface 1a of the casing and the side of the large surface 1a facing the cell 2 is less than 0.05 mm, the increase in discharge capacity is not significant. However, with the continuous charge-discharge cycle, this small gap may lead to a decrease in insulation performance. When the minimum vertical distance h between the outermost electrode 2b facing the large surface 1a of the casing and the side of the large surface 1a facing the cell 2 is greater than 5 mm, the discharge capacity of the battery becomes lower.

[0045] It is understandable that the separator 2a itself also has a certain protective effect. The thicker the separator 2a, the more difficult it is for foreign objects attached to the inside of the casing 1 to pierce the separator 2a. Of course, the thickness of the separator 2a will affect the electrode sheet 2b and its stacking fit. If the thickness of the separator 2a is too large, it will easily lead to the thickness of the cell 2 being too large, affecting the assembly of the cell 2 and the casing 1, and affecting the internal resistance of the battery 100. Therefore, the thickness of the separator 2a should be controlled within a suitable range. For example, as an example of this embodiment, the thickness of the separator 2a is T1, and 6μm≤T1≤400μm. Furthermore, with the diaphragm 2a having a sufficiently good puncture resistance, the battery cell 2 can be moved closer to the housing 1 to further improve the utilization rate of the internal space of the housing 1. Therefore, when the thickness T1 of the outer layer 2a1 satisfies 6μm≤T1≤400μm, the minimum vertical distance between the side of the outermost electrode sheet 2b facing the large surface 1a of the housing and the side of the large surface 1a of the housing facing the battery cell 2 is h, and 0.05mm≤h≤1mm.

[0046] For example, the thickness T1 of the diaphragm 2a can be one of the following dimensions: 6μm, 7μm, 8μm, 9μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, and 400μm. Furthermore, the minimum vertical distance h between the side of the outermost electrode sheet 2b facing the large surface 1a of the housing and the side of the large surface 1a of the housing facing the cell 2 can be one of the following dimensions: 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, and 1mm.

[0047] It should be noted that the diaphragm 2a can be a single-material diaphragm 2a made of PP or PE, or it can be a composite diaphragm 2a, such as a ceramic-coated diaphragm 2a. Different materials will affect the puncture resistance of the diaphragm 2a. Therefore, the puncture resistance of the diaphragm 2a can also be reflected by its puncture strength (PPS). For example, as an example of this embodiment, the puncture resistance of the outer layer 2a1 is PPS, and 200 kgf ≤ PPS ≤ 600 kgf. Furthermore, when the puncture resistance of the diaphragm 2a meets the preset conditions, the puncture resistance of the diaphragm 2a is sufficient to allow the battery cell 2 to move closer to the housing 1, thereby further improving the utilization rate of the internal space of the housing 1. Therefore, when the puncture resistance PPS of the outer layer 2a1 meets the condition of 200kgf≤PPS≤600kgf, the minimum vertical distance between the side of the outermost electrode sheet 2b facing the large surface 1a of the housing and the side of the large surface 1a of the housing facing the battery cell 2 is h, and 0.05mm≤h≤1.5mm.

[0048] For example, the puncture resistance PPS of the outer layer 2a1 can be one of the following values: 200 kgf, 250 kgf, 300 kgf, 350 kgf, 400 kgf, 450 kgf, 500 kgf, 550 kgf, and 600 kgf. Furthermore, the minimum vertical distance h between the side of the outermost electrode sheet 2b facing the large surface 1a of the housing and the side of the large surface 1a of the housing facing the cell 2 can be one of the following dimensions: 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, and 1.5 mm.

[0049] In some batteries 100, an insulating film 3 is disposed between the cell 2 and the casing 1 to ensure the safety, reliability, and performance stability of the battery 100. (Reference) Figure 6 As an example of this embodiment, the battery 100 also includes an insulating film 3, which extends between the outer layer 2a1 and the casing 1 to separate the separator 2a and the casing 1. In this way, the insulating film 3 is disposed between the cell 2 and the casing 1, which can isolate the cell 2 and the casing 1 and prevent the tabs 4 or electrode plates 2b of the cell 2 from contacting the casing 1. Moreover, the insulating film 3 is usually made of a high-resistivity material, and its high-resistivity characteristics can block the leakage circuit between the cell 2 and the casing 1, ensuring that the battery 100 works normally.

[0050] Furthermore, the insulating film 3 provides a certain mechanical protection between the diaphragm 2a and the housing 1, thereby reducing the risk of foreign objects attached to the inside of the housing 1 puncturing the diaphragm 2a. Therefore, with the insulating film 3 in place, the battery cell 2 can be further closer to the housing 1. The minimum vertical distance between the outermost electrode sheet 2b facing the large surface 1a of the housing and the side of the large surface 1a facing the battery cell 2 is h, and 0.05mm≤h≤1mm. For example, the minimum vertical distance h between the outermost electrode sheet 2b facing the large surface 1a of the housing and the side of the large surface 1a facing the battery cell 2 can be one of the following dimensions: 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, and 1mm.

[0051] The insulating film 3 can be bonded to the separator 2a by means of adhesion, mechanical fixation, hot pressing, or lamination. The bonding structure of the two usually depends on the battery type 100, process requirements, and performance requirements. For example, as an example of this embodiment, the insulating film 3 is bonded to the outer layer 2a1. Specifically, the insulating film 3 can be bonded to the separator 2a with glue or hot melt adhesive, which can make the insulating film 3 and the separator 2a firmly connected and prevent relative displacement between the insulating film 3 and the separator 2a. Of course, the adhesive insulating film 3 may also adhere to foreign objects inside the housing 1. In this case, the separator 2a is appropriately located away from the housing 1 to increase the space between the separator 2a and the housing 1 and reduce the possibility of foreign objects being squeezed. Therefore, the minimum vertical distance between the side of the outermost electrode sheet 2b facing the large surface 1a of the housing and the side of the large surface 1a of the housing facing the cell 2 is h, and 0.1mm≤h≤1mm. For example, the minimum vertical distance h between the outermost electrode sheet 2b facing the large surface 1a of the housing and the large surface 1a of the housing facing the cell 2 can be one of the following sizes: 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, and 1mm.

[0052] Understandably, during the assembly of cell 2, the positive electrode 2b1, separator 2a, and negative electrode 2b2 are stacked sequentially. The upper and lower surfaces of electrode 2b are distinguished by the stacking direction of the electrode 2b. The separator 2a is positioned between the positive electrode 2b1 and the negative electrode 2b2, covering both the upper and lower surfaces of the positive and negative electrode 2b1 and 2b2, thereby separating adjacent positive and negative electrode 2b1 and 2b2 and preventing direct contact. Furthermore, the separator 2a is typically a continuously extending thin film, extending from the inside of the stacked structure to the outside, covering the outer side of the stacked structure, thus separating the electrode 2b from the housing 1. (Reference) Figure 3-5 As an example of a separator 2a covering an electrode sheet 2b, the battery cell 2 has a first end 2d and a second end 2e disposed opposite each other in the stacking direction of the electrode sheets 2b; the electrode sheet 2b includes a plurality of first electrode sheets and a plurality of second electrode sheets, namely a plurality of negative electrode sheets 2b2 and a plurality of positive electrode sheets 2b1, the plurality of negative electrode sheets 2b2 and the plurality of positive electrode sheets 2b1 are alternately stacked to form a discontinuous stacked structure, and the negative electrode sheet 2b2 constitutes the outermost layer of the stacked structure at the first end 2d; the separator 2a includes an inner layer segment 2a2 and an outer layer segment 2a3 connected to each other, wherein the inner layer segment 2a2 is disposed between adjacent positive electrode sheets 2b1 and negative electrode sheets 2b2, and the inner layer segment 2a3 is disposed between adjacent positive electrode sheets 2b1 and negative electrode sheets 2b2, and the inner layer segment 2a2 ... The tail end of the layer segment 2a2 is disposed between the negative electrode 2b2 located at the first end 2d and the adjacent positive electrode 2b1; the outer layer segment 2a3 includes a starting end and a ending end. The starting end of the outer layer segment 2a3 is connected to the tail end of the inner layer segment 2a2, and the outer layer segment 2a3 extends towards the second end 2e along the stacking direction of the electrode sheet 2b, and is wound around the outside of the positive electrode 2b1, the negative electrode 2b2 and the inner layer segment 2a2, and covers the side of the negative electrode 2b2 located at the first end 2d facing the large surface 1a of the shell to form the outer layer portion 2a1. The ending end of the outer layer segment 2a3 extends towards the second end 2e and overlaps at least partially with the starting end of the outer layer segment 2a3.

[0053] It should be noted that in this encapsulation example, the overlapping area between the end of the outer layer segment 2a3 and the beginning of the outer layer segment 2a3 will affect the fit between the diaphragm 2a and the electrode sheet 2b. In the stacking direction of electrode sheet 2b, the overlap distance between the tail end and the head end of the outer layer segment 2a3 is m. If the overlap distance m between the tail end and the head end of the outer layer segment 2a3 is too short, it is easy for the tail end and the head end of the outer layer segment 2a3 to separate, resulting in the exposure of the outer negative electrode sheet 2b2, which in turn causes the risk of the negative electrode sheet 2b2 overlapping with the shell 1. If the overlap distance m between the tail end and the head end of the outer layer segment 2a3 is too long, it is easy for the separator 2a on the side of the cell 2 to be too thick, affecting the assembly and fit between the cell 2 and the shell 1. Therefore, the overlap distance m between the tail end and the head end of the outer layer segment 2a3 should be controlled within a certain range. For example, as an example of this embodiment, the overlap distance m between the tail end and the head end of the outer layer segment 2a3 satisfies: 0.2mm≤m≤10mm. In this way, the separator 2a has a better covering effect on the outermost negative electrode sheet 2b2, and the negative electrode sheet 2b2 is less likely to overlap with the shell 1.

[0054] Of course, in this case, the battery cell 2 can also be moved closer to the housing 1 to further improve the utilization rate of the internal space of the housing 1. Therefore, the minimum vertical distance h between the side of the outermost electrode sheet 2b facing the large surface 1a of the housing and the side of the large surface 1a of the housing facing the battery cell 2 can satisfy: 0.05mm≤h≤1.5mm. For example, the overlap distance m between the tail end and the head end of the outer segment 2a3 can be one of the following dimensions: 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm. The minimum vertical distance h between the side of the electrode sheet 2b facing the large surface 1a of the housing and the side of the large surface 1a of the housing facing the cell 2 can be one of the following dimensions: 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, and 1.5mm.

[0055] In the laminated battery cell 2, the cell 2 has a first end 2d and a second end 2e arranged opposite to each other along the stacking direction of the electrode sheets 2b. It should be noted that the separator 2a typically covers the outer side of the negative electrode sheet 2b2 at the first end 2d and the outer side of the negative electrode sheet 2b2 at the second end 2e, i.e., the side of the negative electrode sheet 2b2 facing the second end 2e, to ensure that the negative electrode sheet 2b2 is separated from the housing 1. Therefore, in Figure 3-5In the coating example shown, the inner layer segment 2a2 coats the outer side of the negative electrode 2b2 at the first end 2d, and the tail end of the inner layer segment 2a2 is positioned between the negative electrode 2b2 at the second end 2e and the adjacent positive electrode 2b1. Of course, to facilitate the membrane 2a coating the side of the negative electrode 2b2 at the first end 2d, the beginning of the inner layer segment 2a2 typically starts at the side of the negative electrode 2b2 at the first end 2d and partially coats the side of the negative electrode 2b2 at the first end 2d.

[0056] The inner layer segment 2a2 typically has a leading end, and this leading end covers the side of the negative electrode 2b2 located at the second end 2e. This improves the covering effect of the separator 2a on the negative electrode 2b2, thereby reducing the risk of the negative electrode 2b2 overlapping with the casing 1. Of course, the length of the leading end of the inner layer segment 2a2 should not be too long to avoid excessively increasing the thickness of the side of the cell 2. (Reference) Figure 5 As an example of this embodiment, in the stacking direction of the electrode sheet 2b, the length of the first end of the inner layer segment 2a2 is l, and 0.1mm≤l≤5mm. Of course, as the risk of the negative electrode sheet 2b2 overlapping with the housing 1 is reduced, the battery cell 2 can also be moved closer to the housing 1 to further improve the utilization rate of the internal space of the housing 1. Therefore, the minimum vertical distance h between the side of the outermost electrode sheet 2b facing the large surface 1a of the housing and the side of the large surface 1a of the housing facing the battery cell 2 can satisfy: 0.05mm≤h≤2mm. For example, the length l of the first end of the inner layer segment 2a2 can be one of the following dimensions: 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm. The minimum vertical distance h between the side of the outermost electrode sheet 2b facing the large surface 1a of the housing and the side of the large surface 1a of the housing facing the cell 2 can be one of the following dimensions: 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.5mm, 2mm.

[0057] Depending on the application scenario of battery 100, some battery 100 structures will be equipped with multiple cells 2 to meet different voltage, capacity, and power requirements. (Reference) Figure 7 As an example of this embodiment, the battery 100 includes two cells 2, which are arranged adjacently in the housing 1, and the arrangement direction of the two cells 2 is the same as the stacking direction of the electrode sheet 2b.

[0058] It is important to note that cell 2 will expand during operation. For example, during the charging and discharging of battery 100, lithium ions may be inserted and extracted into the positive and negative electrode materials, which may cause changes in the volume of the electrode materials. Alternatively, the volume changes of the electrode materials during the charging and discharging of battery 100 may generate internal stress, which may also cause cell 2 to expand as a whole. When two or more cells 2 are arranged inside the casing 1, the expansion of one cell 2 may cause the positions of other cells 2 to shift, resulting in cells 2 closer to the casing 1 touching the casing 1, which may lead to the risk of cell 2 overlapping with the casing 1. Therefore, the minimum vertical distance h between the side of the outermost electrode sheet 2b facing the large surface 1a of the casing and the side of the large surface 1a of the casing facing the cell 2 must satisfy: 0.15mm ≤ h ≤ 5mm. For example, the minimum vertical distance h between the outermost electrode sheet 2b facing the large surface 1a of the housing and the large surface 1a of the housing facing the cell 2 can be one of the following values: 0.15mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm.

[0059] When two or more battery cells 2 are disposed within the housing 1, the manner in which the diaphragm 2a covers the battery cells 2 will also affect the assembly and fit between the battery cells 2 and the housing 1. (Reference) Figure 7 Taking a housing 1 containing two battery cells 2 as an example, each battery cell 2 has a first end 2d and a second end 2e arranged opposite each other along the stacking direction of the electrode sheets 2b, with the second ends 2e of two adjacent battery cells 2 arranged opposite each other; and, in Figure 7 In the battery cell 2 shown, the electrode plates 2b are positive electrode plate 2b1 and negative electrode plate 2b2. The positive electrode plate 2b1 and the negative electrode plate 2b2 are stacked alternately to form a stacked structure, and the negative electrode plate 2b2 is located on the outermost layer of the stacked structure.

[0060] In this embodiment, Figure 7 The diaphragm 2a shown is Figure 3 The separator 2a shown has the same covering method. Specifically, the separator 2a includes an inner layer segment 2a2 and an outer layer segment 2a3 connected to each other. The inner layer segment 2a2 covers the outer side of the negative electrode 2b2 at the first end 2d, and the tail end of the inner layer segment 2a2 is arranged between the negative electrode 2b2 at the second end 2e and the adjacent positive electrode 2b1. Furthermore, the head end of the inner layer segment 2a2 covers the side of the negative electrode 2b2 at the first end 2d. It can be understood that the area covered by the head end of the inner layer segment 2a2 will also be different depending on the connection method between the separator 2a and the negative electrode 2b2. In some battery structures 100, the inner layer segment 2a2 can also cover the entire side of the negative electrode 2b2 at the first end 2d.

[0061] The outer layer segment 2a3 of the diaphragm 2a is connected to the tail end of the inner layer segment 2a2, and the outer layer segment 2a3 is wound around the outside of the inner layer segment 2a2 along the stacking direction of the electrode sheet 2b, and covers the negative electrode sheet 2b2 at the second end 2e to form the outer layer portion 2a1. The tail end of the outer layer segment 2a3 extends toward the head end of the outer layer segment 2a3 and overlaps with the head end of the outer layer segment 2a3. In this way, the inner layer segment 2a2 of the separator 2a of each cell 2 can form a first film structure at the first end 2d, and the outer layer segment 2a3 of the separator 2a, wrapped around the outer side of the inner layer segment 2a2, will form a second film structure at the first end 2d. This results in both cells 2 having two film structures at the first end 2d. Consequently, in the stacking direction of the electrode sheets 2b, the distance between the side of the cell 2 at the first end 2d and the electrode sheet 2b at the first end 2d is greater than the distance between the side of the cell 2 at the second end 2e and the electrode sheet 2b at the second end 2e, thereby reducing the risk of foreign objects adhering to the housing 1 puncturing the separator 2a. Of course, as the risk of foreign objects puncturing the separator 2a decreases, the cell 2 can be moved closer to the housing 1 to further improve the utilization rate of the internal space of the housing 1. Therefore, the minimum vertical distance h between the side of the outermost electrode sheet 2b facing the large surface 1a of the housing and the side of the large surface 1a of the housing facing the cell 2 can satisfy: 0.15mm ≤ h ≤ 2mm. For example, the minimum vertical distance h between the outermost electrode sheet 2b facing the large surface 1a of the housing and the large surface 1a of the housing facing the cell 2 can be one of the following sizes: 0.15mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.5mm, and 2mm.

[0062] Of course, the thickness of the cell 2 also affects the risk of foreign objects piercing the separator 2a. The thicker the cell, the more severe the expansion and the greater the expansion distance. Therefore, matching the spacing between the electrode sheet 2b and the casing 1 with the thickness of the cell 2 can further prevent the separator 2a from adhering to the inside of the casing 1, thereby preventing foreign objects attached to the inside of the casing 1 from piercing the separator 2a, causing the cell 2 to overlap with the casing 1, and thus causing a short circuit in the battery 100. As an example of this embodiment, the thickness of the cell 2 is T in the stacking direction of the electrode sheet 2b. 电芯 And 8mm≤T 电芯 ≤30mm. For example, the thickness T of cell 2. 电芯 It can be one of the following values: 8mm, 9mm, 10mm, 11mm, 13mm, 15mm, 18mm, 20mm, 21mm, 23mm, 25mm, 28mm, or 30mm.

[0063] Understandably, the electrode assembly of the battery 100 typically also includes a tab 4 electrically connected to the electrode plate 2b. The tab 4 is electrically connected to the electrode plate 2b and is used to transmit the current from the electrode plate 2b to other components, such as the housing 1 or the terminal post. The terminal post of the battery 100 is typically located on the housing 1, with one end of the terminal post electrically connected to the tab 4 and the other end exposed on the surface of the housing 1.

[0064] The electrode 4 typically includes a positive electrode and a negative electrode. The positive electrode is electrically connected to the positive electrode 2b1, and the negative electrode is electrically connected to the negative electrode 2b2. The battery cell 2 is charged and discharged through the positive and negative electrodes. The electrode typically includes a current collector and an active material layer, with the active material layer coated on the surface of the current collector. If the electrode is the positive electrode 2b1, the current collector can be made of aluminum, and the active material layer can be made of lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. If the electrode is the negative electrode 2b2, the current collector can be made of copper, and the active material layer can be made of carbon or silicon, etc.

[0065] It is important to note that the width of the tab 4 affects the current distribution, mechanical stress, and assembly precision of the battery 100, as well as the risk of the separator 2a being punctured. The width of the tab 4 also affects the current flow path of the entire electrode, thus affecting the expansion of the cell 2. When the width of the tab 4 is within a suitable range, the expansion of the cell 2 can be reduced, and the tab 4 can also act as a buffer to reduce the collision between the cell 2 and the casing 1. If the width of the tab 4 is too small, the current flow path of the entire electrode will be too long, which will easily cause the cell 2 to expand. Furthermore, burrs and other foreign objects are likely to be generated at the connection between the tab 4 and the electrode sheet 2b, affecting the insulation between the cell 2 and the casing 1. If the width of the tab 4 is too large, the edge of the tab 4 is prone to warping, making it difficult to assemble the battery 100, or causing the tab 4 to overlap with the casing 1, affecting the insulation performance. Furthermore, the width of the cell 2 affects the stress distribution inside the battery 100 and also the risk of the separator 2a being punctured. For example, if the width of the cell 2 is too narrow, it may cause stress concentration inside the battery 100, resulting in greater pressure on the separator 2a when the cell 2 expands. If the width of the cell 2 is too wide, it may increase the difficulty of aligning the electrode pieces 2b. Misalignment of the electrode pieces 2b may cause local compression or puncture of the separator 2a. Therefore, the width of the cell 2 and the width of the tab 4 should be appropriately controlled within a suitable range. As an example of this embodiment, the cell 2 includes a tab 4, which is electrically connected to the electrode piece 2b. (Referring to...) Figure 8 The width of cell 2, that is, the length of cell 2 in the width direction, is W. 电芯 The width of tab 4, that is, the length of tab 4 in the width direction, is W. 极耳 Then the two satisfy: Among them, the width direction of cell 2 is Figure 8 The direction of the longer side is shown. For example, It can be one of the following values: 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.

[0066] Based on the aforementioned battery 100, this embodiment also provides a battery module, which includes at least two of the aforementioned batteries 100, and the two batteries 100 are electrically connected by being connected in series or in parallel.

[0067] Based on the above-mentioned battery module, this embodiment also provides a battery pack, which includes a housing and at least two of the aforementioned battery modules, the two battery modules being disposed inside the housing and electrically connected to each other.

[0068] In summary, the battery 100 provided in this embodiment of the invention adjusts the distance between the electrode plate 2b of the battery cell 2 and the casing 1, maintaining the battery cell 2 and the casing 1 at a suitable distance. In this way, when the battery cell 2 is placed into the casing 1, the separator 2a of the battery cell 2 will not adhere to the interior of the casing 1, thereby preventing foreign objects such as metal particles and dust adhering to the interior of the casing 1 from piercing the separator 2a, causing the battery cell 2 to overlap with the casing 1, and thus causing a short circuit in the battery 100. Furthermore, by maintaining the battery cell 2 and the casing 1 at a suitable distance, the battery cell 2 can fully utilize the internal space of the casing 1, ensuring the utilization rate of the internal space of the casing 1. This battery 100 module and battery 100 pack utilize the above-described battery 100 and have the beneficial effects of the battery 100 described above.

[0069] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A battery, characterized in that, include: The shell has a large surface area; A battery cell is disposed within the housing, wherein the battery cell includes a separator and a plurality of electrode sheets, wherein the plurality of electrode sheets are stacked to form a discontinuous stacked structure, and the battery cell has a first end and a second end disposed opposite to each other in the stacking direction of the electrode sheets; the electrode sheets include a plurality of first electrode sheets and a plurality of second electrode sheets, the plurality of first electrode sheets and the plurality of second electrode sheets are alternately stacked to form a discontinuous stacked structure, and the first electrode sheets constitute the outermost layer of the stacked structure at the first end, and the stacking direction of the plurality of electrode sheets faces the large surface of the housing; The diaphragm is disposed between two adjacent electrode plates, and extends at least to the side of the outermost electrode plate facing the large surface of the housing to form an outer layer, covering the side of the outermost electrode plate facing the large surface of the housing to separate the electrode plates and the housing; furthermore, the diaphragm includes an inner layer segment and an outer layer segment connected to each other, wherein the inner layer segment is disposed between adjacent first and second electrode plates, and the tail end of the inner layer segment is disposed between the first electrode plate at the first end and the adjacent second electrode plate; the outer layer segment includes a starting end and a ending end, the starting end is connected to the tail end of the inner layer segment, and the outer layer segment extends towards the second end along the stacking direction of the electrode plates, and is wound around the outside of the first electrode plate, the second electrode plate and the inner layer segment, covering the side of the first electrode plate at the first end facing the large surface of the housing, and the ending end of the outer layer segment extends towards the second end and at least partially overlaps with the starting end of the outer layer segment; furthermore, The minimum vertical distance between the outermost electrode sheet facing the large surface of the housing and the large surface of the housing facing the battery cell is h, and 0.05mm≤h≤5mm.

2. The battery according to claim 1, characterized in that, The thickness of the diaphragm is T1, and 6μm≤T1≤400μm; and the minimum vertical distance between the outermost electrode sheet facing the large surface of the housing and the large surface of the housing facing the battery cell is h, and 0.05mm≤h≤1mm.

3. The battery according to claim 1, characterized in that, The puncture resistance of the outer layer is PPS, and 200kgf≤PPS≤600kgf; and the minimum vertical distance between the outermost electrode sheet facing the large surface of the housing and the large surface of the housing facing the battery cell is h, and 0.05mm≤h≤1.5mm.

4. The battery according to claim 1, characterized in that, The battery also includes an insulating film that extends at least between the outer layer and the housing to separate the separator from the housing; and the minimum vertical distance between the outermost electrode sheet facing the large surface of the housing and the large surface of the housing facing the cell is h, and 0.05mm≤h≤1mm.

5. The battery according to claim 4, characterized in that, The insulating film is bonded to the outer layer, and the minimum vertical distance between the outermost electrode sheet facing the large surface of the housing and the large surface of the housing facing the battery cell is h, and 0.1mm≤h≤1mm.

6. The battery according to claim 1, characterized in that, In the stacking direction of the electrode sheets, the overlap distance between the tail end and the head end of the outermost layer is m, and 0.2mm≤m≤10mm; and the minimum vertical distance between the side of the outermost electrode sheet facing the large surface of the housing and the side of the large surface of the housing facing the battery cell is h, and 0.05mm≤h≤1.5mm.

7. The battery according to claim 1, characterized in that, The first electrode forms the outermost layer of the stacked structure at the second end, and the inner layer segment covers the side of the first electrode at the first end facing the second end, and the tail end of the inner layer segment is disposed between the first electrode at the second end and the adjacent second electrode. Furthermore, the inner layer segment also includes a head end, which at least partially covers the side of the first electrode at the second end.

8. The battery according to claim 7, characterized in that, In the stacking direction of the electrode sheets, the length of the first end of the inner layer segment is l, and 0.1mm≤l≤5mm; and the minimum vertical distance between the outermost electrode sheet facing the large surface of the housing and the large surface of the housing facing the battery cell is h, and 0.05mm≤h≤2mm.

9. The battery according to claim 1, characterized in that, The battery includes at least two cells, which are arranged adjacent to each other within the housing. The two adjacent cells are arranged along the stacking direction. The minimum vertical distance between the outermost electrode sheet facing the large surface of the housing and the large surface of the housing facing the cell is h, and 0.15mm≤h≤5mm.

10. The battery according to claim 9, characterized in that, The battery cell has a first end and a second end arranged opposite to each other along the electrode sheet stacking direction, with the second ends of two adjacent battery cells arranged opposite to each other; and, in the electrode sheet stacking direction, the distance between the side of the battery cell at the first end and the electrode sheet at the first end is greater than the distance between the side of the battery cell at the second end and the electrode sheet at the second end. The minimum vertical distance between the outermost electrode sheet facing the large surface of the housing and the large surface of the housing facing the battery cell is h, and 0.15mm≤h≤2mm.

11. The battery according to claim 1, characterized in that, In the stacking direction of the electrode sheets, the thickness of the battery cell is T. 电芯 And 8mm≤T 电芯 ≤30mm.

12. The battery according to claim 1, characterized in that, The battery cell includes tabs that are electrically connected to the electrode plates, and the width of the battery cell is W. 电芯 The width of the electrode tab is W. 极耳 Then the two satisfy:

13. A battery pack, characterized in that, It includes at least two batteries as described in any one of claims 1-12 and a conductive connector, wherein the two batteries are connected in series or in parallel through the conductive connector to achieve electrical connection.

14. A battery pack, characterized in that, It includes a housing and at least two battery modules as described in claim 13, wherein the two battery modules are disposed within the housing and are electrically connected.

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