Battery, battery module and battery pack

Abstract

The invention discloses a battery, a battery module and a battery pack, and relates to the technical field of batteries, the battery comprises a shell and a battery cell, the shell is provided with a shell large surface, the battery cell is arranged in the shell, the battery cell comprises a laminated diaphragm and a plurality of electrode plates, the lamination direction of the plurality of electrode plates faces the shell large surface, and the battery module is arranged in the shell. The diaphragm at least comprises an outer layer part extending to the electrode plate on the outermost layer, and the outer layer part wraps one side, facing the large surface of the shell, of the electrode plate on the outermost layer so as to separate the electrode plate from the shell; and the minimum vertical distance h between the shell in the area where the large surface of the shell is located and the outer layer part is within a preset range. According to the battery, the distance between the electrode plates of the battery cell and the shell is adjusted, so that the battery cell and the shell are kept within a proper spacing distance, and the situation that the battery cell is in lap joint with the shell and then the battery is short-circuited due to the fact that foreign matters attached to the interior of the shell pierce the diaphragm is prevented. The battery module and the battery pack apply the battery and have the beneficial effects of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly to a battery, a battery module, and a battery pack. Background Art

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

[0003] The separator membrane plays a crucial role in laminated batteries. During the assembly process of laminated batteries, the separator membrane is usually placed between the positive and negative electrodes to prevent direct contact between the two, which could cause a short circuit. However, foreign objects such as metal particles and dust may be introduced during the production of laminated batteries, and these foreign objects adhere to the inside of the battery case. When the battery cell is assembled inside the battery case, these foreign objects may pierce the separator membrane, resulting in direct contact between the positive and negative electrodes, triggering an internal short circuit in the battery and even causing thermal runaway. Summary of the Invention

[0004] The object of the present invention is to provide a battery, a battery module, and a battery pack that can avoid the problem of battery short circuit caused by foreign objects adhering to the inside of the battery case piercing the separator membrane by adjusting the spacing distance between the electrode sheet and the battery case.

[0005] To achieve the above object, the present invention adopts the following technical solutions: A battery, comprising: A case having a large surface of the case; A battery cell disposed inside the case, wherein the battery cell includes a separator membrane and a plurality of electrode sheets, and the plurality of electrode sheets are stacked to form a discontinuous stacked structure, and the stacking direction of the plurality of electrode sheets faces the large surface of the case; the separator membrane is disposed between two adjacent electrode sheets, and the separator membrane extends at least to the side of the outermost electrode sheet facing the large surface of the case to separate the electrode sheet and the case; and, The minimum vertical distance between the side of the outermost electrode sheet facing the large surface of the case and the side of the large surface of the case facing the battery cell is h, and 0.05 mm ≤ h ≤ 5 mm.

[0006] Based on the above battery, the present application further provides a battery module, which includes at least two batteries of any one of the foregoing, and the two batteries are electrically connected in series or in parallel.

[0007] Based on the above battery module, the present application further provides a battery pack, which includes a housing and at least two of the aforementioned battery modules. The two battery modules are disposed within the housing and are electrically connected.

[0008] Compared with the prior art, the battery, battery module, and battery pack implemented in the present invention have the following beneficial effects: By adjusting the distance between the electrode plate of the battery cell and the housing, the battery cell is maintained at an appropriate distance from the housing. In this way, when the battery cell is placed into the housing, the diaphragm of the battery cell will not adhere to the interior of the housing, thereby preventing foreign objects attached to the interior of the housing, such as metal particles, dust, etc., from piercing the diaphragm, resulting in the battery cell being in contact with the housing and further causing a short circuit in the battery. Moreover, by maintaining the battery cell at an appropriate distance from the housing, the battery cell can make full use of the interior space of the housing, ensuring the utilization rate of the interior space of the housing. The battery module and battery pack of the present application apply the above battery and have the beneficial effects possessed by the above battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of the battery in an embodiment of the present invention; Figure 2 is a front view of the battery in an embodiment of the present invention; Figure 3 is Figure 2 a sectional view taken along line A-A in Figure 4 is Figure 3 an enlarged view of B in Figure 5 is Figure 3 an enlarged view of C in Figure 6 is a schematic diagram of the cooperation between the insulating film and the battery cell in an embodiment of the present invention; Figure 7 is a schematic diagram of two battery cells disposed within the housing of the battery in an embodiment of the present invention; Figure 8 is a schematic diagram of the cooperation between the battery cell and the tab in an embodiment of the present invention.

[0010] In the figures, 100, battery; 1, housing; 1a, large surface of the housing; 2, battery cell; 2a, diaphragm; 2a1, outer layer; 2a2, inner segment; 2a3, outer segment; 2b, electrode plate; 2b1, positive electrode plate; 2b2, negative electrode plate; 2c, large surface of the battery cell; 2d, first end; 2e, second end; 3, insulating film; 4, tab; 5, cover plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0011] The following will further describe in detail the specific embodiments of the present invention in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0012] In the description of the present invention, it should be understood that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. The terms "mounted", "connected", and "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0013] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "height", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. in the present invention is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0014] In the description of the present invention, it should be understood that the terms "first" and "second" in the present invention are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0015] Embodiment Reference Figure 1-8 , this embodiment provides a battery 100, including a housing 1, a cover plate 5, and an electric core 2. Among them, the housing 1 has a large surface 1a of the housing, and the cover plate 5 is connected to the housing 1 to isolate the internal space of the housing 1 from the external environment. The electric core 2 is disposed in the housing 1, and the electric core 2 includes a separator 2a and a plurality of electrode sheets 2b. The plurality of electrode sheets 2b are stacked to form a discontinuous stacked structure, and the stacking direction of the plurality of electrode sheets 2b faces the large surface 1a of the housing. The separator 2a is disposed between two adjacent electrode sheets 2b, and the separator 2a at least extends to the side of the outermost electrode sheet 2b facing the large surface 1a of the housing to form an outer layer portion 2a1. The outer layer portion 2a1 covers the side of the outermost electrode sheet 2b facing the large surface 1a of the housing to separate the electrode sheet 2b and the housing 1 and form a large surface 2c of the electric core.

[0016] 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 laminating multiple electrode sheets. It stacks the positive electrode, negative electrode, and separator alternately into a multi-layer structure. Among them, the positive electrode sheet is usually a metal foil (usually aluminum foil) coated with a 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 a negative electrode active material (such as graphite, silicon-based materials, etc.), and the separator is an insulating film located between the positive and negative electrodes, which is used to prevent short circuits while allowing lithium ions to pass through.

[0017] It should be noted that the housing 1 is used to encapsulate components such as the battery cell 2 and the electrolyte. The housing 1 can be of various shapes and sizes, such as cuboid, hexagonal prism, etc. The shape of the housing 1 can be determined according to the specific shape and size of the battery cell 2. The material of the housing 1 can be various, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0018] It should be noted that the large surface 1a of the housing is the surface with the largest area in the housing 1 of this battery 100. The large surface 1a of the housing is usually the main load-bearing part of the housing 1, which affects the overall structural strength of the housing 1. And, it is usually also the main area for heat dissipation of the housing 1, which affects the heat dissipation efficiency of the battery 100.

[0019] It should be noted that the large surface 2c of the battery cell refers to the larger side surface of the battery cell 2. It is usually the part with the largest area of the battery cell 2 when the electrode sheets 2b and the separator 2a are laminated. And, the large surface 2c of the battery cell is usually perpendicular to the lamination direction of the electrode sheets 2b.

[0020] It can be understood that the electrode sheets 2b of the battery 100 usually include two types of electrode sheets with opposite polarities, namely the positive electrode sheet 2b1 as the second electrode sheet and the negative electrode sheet 2b2 as the first electrode sheet. The electrode assembly of the battery 100 works by the movement of metal ions between the positive electrode sheet 2b1 and the negative electrode sheet 2b2. The cycle process of the battery cell is the process of metal ions moving from the positive electrode sheet 2b1 to the negative electrode sheet 2b2 and then from the negative electrode sheet 2b2 to the positive electrode sheet 2b1. Refer to Figure 3 , in the battery cell 2 of this embodiment, the positive electrode sheet 2b1 and the negative electrode sheet 2b2 are alternately laminated in sequence, that is, the positive electrode sheet 2b1 and the negative electrode sheet 2b2 are stacked in the order of negative electrode sheet 2b2 - positive electrode sheet 2b1 - negative electrode sheet 2b2 - positive electrode sheet 2b1 - negative electrode sheet 2b2 in sequence, so as to form a discontinuous laminated structure, and the negative electrode sheet 2b2 is located on the outermost layer of the laminated structure, that is, on the side facing the large surface 1a of the housing.

[0021] It should be noted that the battery cell 2 in this embodiment is a stacked battery cell, and multiple electrode sheets 2b are stacked to form a discontinuous stacked structure, which means that any two adjacent positive electrode sheets 2b1 are in a discontinuous structure and / or any two adjacent negative electrode sheets 2b2 are in a discontinuous structure.

[0022] During the production and manufacturing process of the battery 100, since the electrode sheet 2b has a discontinuous structure, the electrode sheet 2b needs to be cut to form single-piece electrode sheets and then stacked to form the battery cell 2. The cut part of the electrode sheet 2b is the weak part of the electrode sheet. During the use of the battery 100, the corners and cut parts of the electrode sheet 2b are prone to being pressed and losing material, thereby piercing the separator 2a and causing the battery cell 2 to be short-circuited with the housing 1. At the same time, during the use of the battery 100, the large surface 2c of the battery cell is prone to swelling, which will also increase the risk of short circuit between the battery cell 2 and the housing 1. Therefore, the battery 100 in this embodiment adjusts the distance between the electrode sheet 2b and the housing 1 so that 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 0.05 mm ≤ h ≤ 5 mm.

[0023] Exemplarily, 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 be one of the dimensions of 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, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm.

[0024] By adjusting the distance between the electrode sheet 2b of the battery cell 2 and the housing 1, the battery cell 2 and the housing 1 are maintained at an appropriate interval distance. In this way, when the battery cell 2 is placed in the housing 1, the separator 2a of the battery cell 2 will not adhere to the inside of the housing 1, thereby preventing foreign objects attached to the inside of the housing 1, such as metal particles, dust, etc. from piercing the separator 2a, resulting in the battery cell 2 being in contact with the housing 1 and further causing the battery 100 to short-circuit. Moreover, by maintaining the battery cell 2 and the housing 1 at an appropriate interval distance, the battery cell 2 can make full use of the internal space of the housing 1 and ensure the utilization rate of the internal space of the housing 1.

[0025] In order to verify that when the minimum vertical distance h of the battery 100 provided in this embodiment meets the above range, compared with other batteries 100, the battery 100 in this embodiment can ensure good insulation performance, 10 groups of tests were carried out in this embodiment, referring to Table 1 below: In Table 1, Test Examples 1 to 10 were tested based on the structure of the battery 100 of this embodiment, that is, for the batteries 100 in Test Examples 1 to 10, their minimum vertical spacing h satisfied the above range. Comparative Examples 1 to 2 were other battery structures, that is, their minimum vertical spacing h did not satisfy the above range.

[0026] Insulation performance test method: As shown in Table 1, the battery cell and the housing were assembled at different heights h, and the cover plate was welded and fixed to the housing using laser welding technology. After completing the liquid injection and formation processes, battery samples with the same size were obtained; the battery cathode material was lithium iron phosphate. First, the battery was charged to 3.25 V at a current of 1 / 3C, and after standing for 10 minutes, it was discharged to 2.5 V at a current of 1 / 3C and then stood for 1 hour. At this time, the open-circuit voltage of the battery was measured and recorded, marked as V1. Subsequently, the above charging and discharging processes were repeated, and after standing for 10 minutes, 500 cycles were performed. After the cycles were completed, it was left standing 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 cycling was calculated according to the formula △V = V1 - V2. The larger the voltage difference value, the worse the insulation performance of the battery cells; conversely, the smaller the voltage difference value, the better the insulation performance of the battery cells.

[0027] Discharge capacity test method: According to the assembly requirements at different heights h in Table 1, the battery cell and the housing were assembled, and the cover plate was welded to the housing through laser welding technology. After completing the liquid injection and formation steps, battery samples with the same size were obtained; the battery cathode material was also lithium iron phosphate. First, the battery was charged to 3.25 V at a current of 1 / 3C, and after standing for 10 minutes, it was discharged to 2.5 V at a current of 1 / 3C and then stood for 10 minutes. Then, it was charged to 3.25 V again at a current of 1 / 3C, and after standing for 10 minutes, it was discharged at a constant current of 10A to 2.5 V, and the discharge time was recorded, marked as T hours. The discharge capacity of the battery was calculated according to the formula C = 10×T. If the calculated capacity was less than 100 Ah, the battery sample was determined to be unqualified.

[0028] Table 1 As can be seen from Table 1, when 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 satisfies the above range, the voltage difference of the battery 100 is small, the insulation performance is good, and the discharge capacity of the battery 100 is good. When 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 is less than 0.05 mm, the improvement of the discharge capacity is not significant. However, with the continuous charge and discharge cycles, such a small gap may lead to a decrease in insulation performance. When 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 is greater than 5 mm, the discharge capacity of the battery will become lower.

[0029] It can be understood 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 inside the housing 1 to pierce the separator 2a. Of course, the thickness of the separator 2a will affect the lamination and cooperation with the electrode sheet 2b. If the thickness of the separator 2a is too large, it is easy to cause the thickness of the battery cell 2 to be too large, affecting the assembly of the battery cell 2 and the housing 1 and the internal resistance of the battery 100. Therefore, the thickness of the separator 2a should be appropriately controlled within a suitable range. For example, as an example of this embodiment, the thickness of the separator 2a is , and 6 μm ≤ ≤ 400 μm. And when the separator 2a has a sufficiently good anti-piercing effect, the battery cell 2 can be further close to the housing 1 to further improve the utilization rate of the internal space of the housing 1. Therefore, when the thickness of the outer layer portion 2a1 satisfies 6 μm ≤ ≤ 400 μm, 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 is such that 0.05 mm ≤ h ≤ 1 mm.

[0030] Exemplarily, the thickness of the separator 2a can be one of the dimensions of 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm. And 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 be one of the dimensions of 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.

[0031] It should be noted that the separator 2a can be a single-material separator 2a made of PP material or PE material, or a composite separator 2a, such as a ceramic-coated separator 2a. Materials of different materials will also affect the puncture resistance effect of the separator 2a. Therefore, the puncture resistance ability of the separator 2a can also be reflected by the puncture strength (Puncture Puncture Strength, PPS). For example, as an example of this embodiment, the puncture strength of the outer layer 2a1 is PPS, and 200 kgf ≤ PPS ≤ 600 kgf. Moreover, when the puncture strength of the separator 2a meets the preset conditions, the puncture resistance ability of the separator 2a is sufficient to enable the battery cell 2 to be closer to the housing 1, so as to further improve the utilization rate of the internal space of the housing 1. Therefore, when the puncture strength PPS of the outer layer 2a1 satisfies 200 kgf ≤ PPS ≤ 600 kgf, 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 is h, and 0.05 mm ≤ h ≤ 1.5 mm.

[0032] Exemplarily, the puncture strength PPS of the outer layer 2a1 can be one of the values of 200 kgf, 250 kgf, 300 kgf, 350 kgf, 400 kgf, 450 kgf, 500 kgf, 550 kgf, 600 kgf. Moreover, 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 be one of the dimensions of 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, 1.5 mm.

[0033] In some batteries 100, an insulating film 3 is disposed between the battery cell 2 and the housing 1 to ensure the safety, reliability, and performance stability of the battery 100. Refer to Figure 6 , as an example of this embodiment, the battery 100 further includes an insulating film 3. The insulating film 3 extends between the outer layer 2a1 and the housing 1 to separate the separator 2a from the housing 1. In this way, the insulating film 3 is disposed between the battery cell 2 and the housing 1, and can isolate the battery cell 2 from the housing 1, preventing the tab 4 or the electrode sheet 2b of the battery cell 2 from contacting the housing 1. Moreover, the insulating film 3 is usually made of a high-resistance material, and its high-resistance characteristic can block the leakage path between the battery cell 2 and the housing 1, ensuring the normal operation of the battery 100.

[0034] Moreover, the insulating film 3 can provide a certain mechanical protection effect between the separator 2a and the housing 1, thereby reducing the risk of foreign objects attached to the inside of the housing 1 piercing the separator 2a. Therefore, when the insulating film 3 is configured, the battery cell 2 can be further close to the housing 1. 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 0.05 mm ≤ h ≤ 1 mm. Exemplarily, 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 be one of the dimensions of 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.

[0035] The insulating film 3 can be cooperated with the separator 2a by means of bonding, mechanical fixing, hot pressing or laminating, etc. The cooperation structure between the two usually depends on the type of the battery 100, process requirements and performance requirements. For example, as an example of this embodiment, the insulating film 3 is bonded to the outer layer portion 2a1. Specifically, the insulating film 3 can be bonded to the separator 2a by using glue or hot melt adhesive, so that the insulating film 3 can be firmly connected to the separator 2a and prevent relative displacement between the insulating film 3 and the separator 2a. Of course, the sticky insulating film 3 may also adhere to foreign objects inside the housing 1. In this regard, the separator 2a is preferably appropriately 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 battery cell 2 is h, and 0.1 mm ≤ h ≤ 1 mm. Exemplarily, 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 be one of the dimensions of 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.

[0036] It can be understood that during the assembly process of the battery cell 2, the positive electrode sheet 2b1, the separator 2a and the negative electrode sheet 2b2 are stacked in sequence. Among them, the upper surface and the lower surface of the electrode sheet 2b are distinguished by the stacking direction of the electrode sheet 2b. The separator 2a is disposed between the positive electrode sheet 2b1 and the negative electrode sheet 2b2, covering the upper surface and the lower surface of the positive electrode sheet 2b1 and the negative electrode sheet 2b2, so as to separate the adjacent positive electrode sheet 2b1 and negative electrode sheet 2b2 and prevent the adjacent positive electrode sheet 2b1 and negative electrode sheet 2b2 from directly contacting. Moreover, the separator 2a is usually a continuous stretched film, which stretches from the inside of the stacked structure to the outside of the stacked structure and covers the outside of the stacked structure, so as to separate the electrode sheet 2b from the housing 1. Refer to Figures 3-5, as an example of the separator 2a covering the electrode sheet 2b, the battery cell 2 has a first end 2d and a second end 2e oppositely arranged in the stacking direction of the electrode sheet 2b; the electrode sheet 2b includes a plurality of first electrode sheets and a plurality of second electrode sheets, that is, a plurality of negative electrode sheets 2b2 and a plurality of positive electrode sheets 2b1, and 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 a connected inner layer section 2a2 and an outer layer section 2a3, wherein the inner layer section 2a2 is disposed between the adjacent positive electrode sheet 2b1 and the negative electrode sheet 2b2, and the tail end of the inner layer section 2a2 is disposed between the negative electrode sheet 2b2 at the first end 2d and the adjacent positive electrode sheet 2b1; the outer layer section 2a3 includes a starting end and a terminating end, the starting end of the outer layer section 2a3 is connected to the tail end of the inner layer section 2a2, and the outer layer section 2a3 extends along the stacking direction of the electrode sheet 2b towards the second end 2e, and winds around the outside of the positive electrode sheet 2b1, the negative electrode sheet 2b2, and the inner layer section 2a2, and covers the side of the negative electrode sheet 2b2 at the first end 2d facing the large surface 1a of the housing, so as to form an outer layer portion 2a1, and furthermore, the terminating end of the outer layer section 2a3 extends towards the second end 2e and at least partially overlaps with the starting end of the outer layer section 2a3.

[0037] It should be noted that in this covering example, the overlapping area between the terminating end and the starting end of the outer layer section 2a3 will affect the cooperation between the separator 2a and the electrode sheet 2b. In the stacking direction of the electrode sheet 2b, the overlapping distance between the terminating end and the starting end of the outer layer section 2a3 is m. If the overlapping distance m between the terminating end and the starting end of the outer layer section 2a3 is too short, it is easy to cause the separation between the terminating end and the starting end of the outer layer section 2a3, resulting in the exposure of the outermost negative electrode sheet 2b2, and further causing the risk of the negative electrode sheet 2b2 being in contact with the housing 1. If the overlapping distance m between the terminating end and the starting end of the outer layer section 2a3 is too long, it is easy to cause the separator 2a on the side of the battery cell 2 to be too thick, affecting the assembly cooperation between the battery cell 2 and the housing 1. Therefore, the overlapping distance m between the terminating end and the starting end of the outer layer section 2a3 is preferably controlled within a certain range. For example, as an example of this embodiment, the overlapping distance m between the terminating end and the starting end of the outer layer section 2a3 satisfies: 0.2 mm ≤ m ≤ 10 mm. In this way, the covering effect of the separator 2a on the outermost negative electrode sheet 2b2 is better, and the negative electrode sheet 2b2 is not easily in contact with the housing 1.

[0038] Of course, in this case, the battery cell 2 can also be further close 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: 0.05 mm ≤ h ≤ 1.5 mm. Exemplarily, the overlapping distance m between the tail end and the head end of the outer layer segment 2a3 can be one of the dimensions of 0.2 mm, 0.3 mm, 0.4 m, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, and 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 be one of the dimensions of 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, 1.5 mm.

[0039] In the stacked battery cell 2, the battery cell 2 has a first end 2d and a second end 2e which are oppositely arranged along the stacking direction of the electrode sheets 2b. It should be noted that the separator 2a usually covers the outside of the negative electrode sheet 2b2 at the first end 2d and the outside of the negative electrode sheet 2b2 at the second end 2e, that is, the side of the negative electrode sheet 2b2 facing the second end 2e, so as to ensure the separation between the negative electrode sheet 2b2 and the housing 1. Therefore, in Figures 3-5 the shown covering example, the inner layer segment 2a2 covers the outside of the negative electrode sheet 2b2 at the first end 2d, and the tail end of the inner layer segment 2a2 is arranged between the negative electrode sheet 2b2 at the second end 2e and the adjacent positive electrode sheet 2b1. Of course, in order to facilitate the separator 2a to cover the side surface of the negative electrode sheet 2b2 at the first end 2d, the head end of the inner layer segment 2a2 usually starts from the side surface of the negative electrode sheet 2b2 at the first end 2d and partially covers the side surface of the negative electrode sheet 2b2 at the first end 2d.

[0040] The inner layer segment 2a2 usually has a head end, and the head end of the inner layer segment 2a2 covers the side surface of the negative electrode sheet 2b2 at the second end 2e, which can improve the covering effect of the separator 2a on the negative electrode sheet 2b2, thereby reducing the risk of the negative electrode sheet 2b2 overlapping with the housing 1. Of course, the length of the head end of the inner layer segment 2a2 should not be too long to avoid excessively increasing the thickness of the side surface of the battery cell 2. Refer to Figure 5, as an example of this embodiment, in the stacking direction of the electrode sheet 2b, the length of the leading end of the inner layer segment 2a2 is l, and 0.1 mm ≤ l ≤ 5 mm. Of course, as the risk of the negative electrode sheet 2b2 overlapping with the housing 1 decreases, the battery cell 2 can also be further close 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: 0.05 mm ≤ h ≤ 2 mm. Exemplarily, the length l of the leading end of the inner layer segment 2a2 can be one of the dimensions of 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, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, and 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 be one of the dimensions of 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, 1.5 mm, 2 mm.

[0041] According to the application scenarios of the battery 100, multiple battery cells 2 are configured in some battery 100 structures to meet different voltage, capacity, and power requirements. Refer to Figure 7 , as an example of this embodiment, the battery 100 includes two battery cells 2. The two battery cells 2 are arranged adjacent to each other in the housing 1, and the arrangement direction of the two battery cells 2 is the same as the stacking direction of the electrode sheet 2b.

[0042] It should be noted that the battery cell 2 will expand during operation. For example, during the charge and discharge process of the battery 100, lithium ions are inserted into and extracted from the positive and negative electrode materials, which may cause changes in the volume of the electrode materials. Or, during the charge and discharge process of the battery 100, the volume change of the electrode materials will generate internal stress, which may also cause the overall expansion of the battery cell 2. When two or more battery cells 2 are arranged in the housing 1, the expansion of one battery cell 2 will cause the displacement of the other battery cells 2, and then cause the battery cell 2 close to the housing 1 to be close to the housing 1, resulting in the risk of the battery cell 2 overlapping with 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 should satisfy: 0.15 mm ≤ h ≤ 5 mm. Exemplarily, 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 be one of the values of 0.15 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, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm.

[0043] When two or more battery cells 2 are arranged in the housing 1, the way the separator 2a wraps the battery cell 2 will also affect the assembly and cooperation between the battery cell 2 and the housing 1. Refer to Figure 7 , taking the case where two battery cells 2 are arranged in the housing 1 as an example, the battery cell 2 has a first end 2d and a second end 2e that are oppositely arranged along the stacking direction of the electrode sheet 2b, and the second ends 2e of two adjacent battery cells 2 are oppositely arranged; and, in Figure 7 the shown battery cell 2, the electrode sheet 2b is a positive electrode sheet 2b1 and a negative electrode sheet 2b2, and the positive electrode sheet 2b1 and the negative electrode sheet 2b2 are alternately stacked in sequence to form a stacked structure, and the negative electrode sheet 2b2 is located at the outermost layer of the stacked structure.

[0044] In this embodiment, Figure 7 the shown separator 2a has the same wrapping method as Figure 3 the shown separator 2a. Specifically, the separator 2a includes an inner layer section 2a2 and an outer layer section 2a3 that are connected. Among them, the inner layer section 2a2 wraps the outside of the negative electrode sheet 2b2 at the first end 2d, and the tail end of the inner layer section 2a2 is arranged between the negative electrode sheet 2b2 at the second end 2e and the adjacent positive electrode sheet 2b1, and the head end part of the inner layer section 2a2 wraps the side surface of the negative electrode sheet 2b2 at the first end 2d. It can be understood that according to the different connection methods between the separator 2a and the negative electrode sheet 2b2, the covered area of the head end of the inner layer section 2a2 will also be different. In some battery 100 structures, the inner layer section 2a2 can also cover the entire side surface of the negative electrode sheet 2b2 at the first end 2d.

[0045] The outer layer segment 2a3 of the separator 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, and 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 battery cell 2 can form a first layer of film structure at the first end 2d, and the outer layer segment 2a3 of the separator 2a wound around the outside of the inner layer segment 2a2 will form a second layer of film structure at the first end 2d, so that both battery cells 2 have two layers of film structure at the first end 2d. Thus, in the stacking direction of the electrode sheet 2b, the distance between the side surface of the battery 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 surface of the battery cell 2 at the second end 2e and the electrode sheet 2b at the second end 2e, thereby reducing the risk of foreign objects attached inside the housing 1 piercing the separator 2a. Of course, as the risk of foreign objects piercing the separator 2a decreases, the battery cell 2 can be further close 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: 0.15 mm ≤ h ≤ 2 mm. Exemplarily, 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 be one of the dimensions of 0.15 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, 1.5 mm, 2 mm.

[0046] Of course, the thickness of the battery cell 2 will also affect the risk of foreign objects piercing the separator 2a. The thicker the battery, the more serious the swelling condition and the greater the swelling distance. Therefore, matching the distance between the electrode sheet 2b and the housing 1 with the thickness of the battery cell 2 can further prevent the separator 2a from adhering to the inside of the housing 1, thereby preventing foreign objects attached inside the housing 1 from piercing the separator 2a, resulting in the battery cell 2 overlapping with the housing 1, and further causing the battery 100 to short circuit. As an example of this embodiment, in the stacking direction of the electrode sheet 2b, the thickness of the battery cell 2 is , and 8 mm ≤ ≤ 30 mm. Exemplarily, the thickness of the battery cell 2 can be one of the values of 8 mm, 9 mm, 10 mm, 11 mm, 13 mm, 15 mm, 18 mm, 20 mm, 21 mm, 23 mm, 25 mm, 28 mm, 30 mm.

[0047] It can be understood that the electrode assembly of the battery 100 generally further includes a tab 4 electrically connected to the electrode sheet 2b. The tab 4 is electrically connected to the electrode sheet 2b and is used to transmit the current of the electrode sheet 2b to other components, such as the housing 1 or the terminal post, through the tab 4. The terminal post of the battery 100 is usually provided on the housing 1, and one end of the terminal post is electrically connected to the tab 4, and the other end is exposed on the surface of the housing 1.

[0048] The tab 4 generally includes a positive tab and a negative tab. Among them, the positive tab is electrically connected to the positive electrode sheet 2b1, and the negative tab is electrically connected to the negative electrode sheet 2b2. The battery cell 2 realizes charging and discharging through the positive tab and the negative tab. The electrode sheet generally includes a current collector and an active material layer, and the active material layer is coated on the surface of the current collector. If the electrode sheet is the positive electrode sheet 2b1, the material of the current collector can be aluminum, and the material of the active material layer can be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, etc. If the electrode sheet is the negative electrode sheet 2b2, the material of the current collector can be copper, and the material of the active material layer can be carbon or silicon, etc.

[0049] It should be noted that the width of the tab 4 will affect the current distribution, mechanical stress and assembly accuracy of the battery 100, affect the risk of the separator 2a being punctured, the width of the tab 4 will affect the over-current path of the current of the entire electrode sheet, thereby affecting the swelling of the battery cell 2. When the width of the tab 4 is within a suitable range, the swelling of the battery cell 2 can be reduced, and the tab 4 can serve as a buffer part to reduce the collision between the battery cell 2 and the housing 1. If the width of the tab 4 is too small, the over-current path of the current of the entire electrode sheet is relatively long, which is likely to cause the swelling of the battery cell 2, and foreign matters such as burrs are likely to be generated at the connection between the tab 4 and the electrode sheet 2b, affecting the insulation between the battery cell 2 and the housing 1. If the width of the tab 4 is too large, the edge of the tab 4 is likely to warp, resulting in difficult assembly of the battery 100, or causing the tab 4 to overlap with the housing 1, affecting the insulation performance. Moreover, the width of the battery cell 2 will affect the stress distribution inside the battery 100 and also affect the risk of the separator 2a being punctured. For example, if the width of the battery cell 2 is too narrow, it may cause stress concentration inside the battery 100, and the battery cell 2 generates a greater pressure on the separator 2a when swelling. If the width of the battery cell 2 is too wide, it may increase the difficulty of aligning the electrode sheet 2b. When the electrode sheet 2b is misaligned, it may cause local extrusion or puncture of the separator 2a. Therefore, the width of the battery cell 2 and the width of the tab 4 should be appropriately controlled within a suitable range. As an example of this embodiment, the battery cell 2 includes a tab 4, and the tab 4 is electrically connected to the electrode sheet 2b. And, referring to Figure 8 , the width of the battery cell 2, that is, the length of the battery cell 2 in the width direction is , the width of the tab 4, that is, the length of the tab 4 in the width direction is , then the two satisfy: 0.2 ≤ ≤ 1, where the width direction of the battery cell 2 is the Figure 8 long side direction shown. Exemplarily, It can be one of the values 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.

[0050] Based on the above battery 100, this embodiment further provides a battery module, which includes at least two of any one of the foregoing batteries 100, and the two batteries 100 are electrically connected in series or in parallel.

[0051] Based on the above battery module, this embodiment further provides a battery pack, which includes a housing and at least two of the foregoing battery modules. The two battery modules are disposed in the housing and are electrically connected.

[0052] In summary, for the battery 100 provided in the embodiment of the present invention, by adjusting the distance between the electrode plate 2b of the battery cell 2 and the housing 1, the battery cell 2 and the housing 1 are maintained at an appropriate distance. In this way, when the battery cell 2 is placed in the housing 1, the separator 2a of the battery cell 2 does not adhere to the inside of the housing 1, thereby preventing foreign objects attached to the inside of the housing 1, such as metal particles, dust, etc. from piercing the separator 2a, resulting in the battery cell 2 and the housing 1 being in contact, and further causing the battery 100 to short-circuit. Moreover, by maintaining the battery cell 2 and the housing 1 at an appropriate distance, the battery cell 2 can make full use of the internal space of the housing 1, ensuring the utilization rate of the internal space of the housing 1. The battery 100 module and the battery 100 pack apply the above battery 100 and have the beneficial effects possessed by the above battery 100.

[0053] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A battery, characterized in that, Comprising: A housing having a large surface of the housing; An electric core disposed within the housing. The electric core includes a separator and a plurality of electrode sheets. The plurality of electrode sheets are stacked to form a discontinuous stacked structure, and the stacking direction of the plurality of electrode sheets faces the large surface of the housing. The separator is disposed between two adjacent electrode sheets, and the separator extends at least to the side of the outermost electrode sheet facing the large surface of the housing to separate the electrode sheet from the housing. 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 electric core is h, and 0.05 mm ≤ h ≤ 5 mm.

2. The battery according to claim 1, characterized in that, The thickness of the separator is , and 6 μm ≤ ≤ 400 μm; 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 0.05 mm ≤ h ≤ 1 mm.

3. The battery according to claim 1, characterized in that, The puncture resistance of the outer layer is PPS, and 200 kgf ≤ PPS ≤ 600 kgf. 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 electric core is h, and 0.05 mm ≤ h ≤ 1.5 mm.

4. The battery according to claim 1, characterized in that, The battery further 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 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 electric core is h, and 0.05 mm ≤ h ≤ 1 mm.

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 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 electric core is h, and 0.1 mm ≤ h ≤ 1 mm.

6. The battery according to claim 1, characterized in that, The electric core 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 sheet constitutes the outermost layer at the first end of the stacked structure. The separator includes an inner layer segment and an outer layer segment connected to each other. The inner layer segment is disposed between the adjacent first electrode sheet and the second electrode sheet, and the tail end of the inner layer segment is disposed between the first electrode sheet at the first end and the adjacent second electrode sheet. The outer layer segment includes a starting end and a terminating end. The starting end is connected to the tail end of the inner layer segment, and the outer layer segment extends along the stacking direction of the electrode sheets toward the second end, winds around the outside of the first electrode sheet, the second electrode sheet, and the inner layer segment, and covers the side of the first electrode sheet at the first end facing the large surface of the housing. And, the terminating end of the outer layer segment extends toward the second end and at least partially overlaps with the starting end of the outer layer segment.

7. The battery according to claim 6, characterized in that, In the stacking direction of the electrode sheets, the overlapping distance between the tail end and the head end of the outer layer segment is m, and 0.2 mm ≤ m ≤ 10 mm. 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 electric core is h, and 0.05 mm ≤ h ≤ 1.5 mm.

8. The battery according to claim 6, characterized in that, The first pole piece forms the outermost layer of the laminated structure at the second end, and the inner layer section covers the side of the first pole piece at the first end facing the second end. The tail end of the inner layer section is disposed between the first pole piece at the second end and the adjacent second pole piece. Moreover, the inner layer section further includes a head end, and the head end at least partially covers the side surface of the first pole piece at the second end.

9. The battery according to claim 8, characterized in that, In the stacking direction of the electrode sheets, the length of the head end of the inner layer section is l, and 0.1 mm ≤ l ≤ 5 mm. 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 0.05 mm ≤ h ≤ 2 mm.

10. The battery according to claim 1 or 6, characterized in that, The battery includes at least two battery cells. The two battery cells are arranged adjacent to each other in the housing, and the adjacent two battery cells are arranged along the stacking direction. 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 0.15 mm ≤ h ≤ 5 mm.

11. The battery according to claim 10, characterized in that, The battery cell has a first end and a second end that are arranged opposite to each other in the stacking direction of the electrode sheets. The second ends of the adjacent two battery cells are arranged opposite to each other. And in the stacking direction of the electrode sheets, the distance between the side surface of the battery cell at the first end and the electrode sheet at the first end is greater than the distance between the side surface of the battery cell at the second end and the electrode sheet at the second end. Also, 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 0.15 mm ≤ h ≤ 2 mm.

12. The battery according to claim 1, characterized in that, In the stacking direction of the electrode sheet, the thickness of the battery cell is , and 8 mm ≤ ≤ 30 mm.

13. The battery according to claim 1, characterized in that, The battery cell includes tab(s), the tab(s) is / are electrically connected to the electrode sheet, and the width of the battery cell is , and the width of the tab(s) is , then the two satisfy: 0.2 ≤ ≤ 1.

14. A battery pack, characterized in that, It includes at least two batteries according to any one of claims 1-13 and a conductive connection member. The two batteries are connected in series or in parallel through the conductive connection member to achieve electrical connection.

15. A battery module, characterized in that, It includes a housing and at least two battery modules according to claim 14. The two battery modules are arranged in the housing, and the two battery modules are electrically connected.

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