Batteries, battery packs, and electric vehicles

Abstract

The present invention provides a battery (100), a battery pack (200), and an electric vehicle (1000), wherein the battery (100) includes a sealed metal case (11), at least two sealed storage cavities located within the metal case (11), a plurality of electrode body sets (12), and a packaging film (13), wherein the electrode body sets (12) are arranged along a first direction (A), the electrode body sets (12) are connected in series, and the length of the electrode body sets (12) extends along the first direction (A), and the electrode body sets (12) include an electrode body set body (123), a first electrode (121), and a second electrode (122) that draws current. The battery (100) includes a first electrode (121) and a second electrode (122) located on either side of the electrode assembly set body (123) along a first direction (A), at least one accommodating cavity surrounded by a packaging film (13), and the electrode assembly set body (123) is provided within the accommodating cavity, the length (L) of the battery (100) extends along the first direction (A), the length (L) of the battery (100) is 400 mm to 2500 mm, and the thickness (D) of the battery (100) extends along a second direction (B) perpendicular to the first direction (A), and the ratio of the length (L) to the thickness (D) of the battery (100) is 5 to 250.

Description

Technical Field

[0001] (Cross - reference to related applications) This application claims the priority of Chinese Patent Application No. "202010032935.3" with the invention title of "Battery, Battery Pack and Electric Vehicle" filed by BYD Company Limited on January 13, 2020, and all its contents are incorporated herein by reference.

[0002] This application belongs to the field of batteries, and particularly relates to batteries, battery packs and electric vehicles.

Background Art

[0003] A battery pack applied to an electric vehicle generally includes a plurality of batteries mounted in a case of the battery pack so as to improve the battery capacity.

[0004] Since it is necessary to add an electrolyte during the manufacturing process of the battery, it is necessary to seal the battery to prevent leakage of the electrolyte. In the prior art, generally, the electrode body is directly sealed in the case, then the electrolyte is injected from the injection port on the case, and after the electrolyte injection is completed, the injection port is sealed to obtain the battery. However, in the above method, since the electrode body and the electrolyte are directly packaged in the case of the battery, when the case is damaged, the electrolyte is likely to leak and the sealing effect is low.

[0005] Also, when a conventional battery includes a plurality of electrode bodies, the plurality of electrode bodies are usually arranged in a parallel (i.e., row array) manner, but such an arrangement method is disadvantageous for the series connection of the plurality of electrode bodies, and it is necessary to provide long lead wires to connect the positive and negative terminals between the electrode bodies.

Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems in the prior art. To this end, a battery according to a first aspect of the present invention includes a sealed metal case, at least two sealed housing cavities located within the metal case, a plurality of electrode sets and a package film, wherein the arrangement direction of the electrode sets is a first direction, the electrode sets are connected in series, the length of the electrode sets extends along the first direction, the electrode sets include an electrode set body and a first electrode and a second electrode for drawing current, the first electrode and the second electrode are located on both sides of the electrode set body, respectively, along the first direction, at least one of the housing cavities is surrounded by the package film, the electrode set body is provided within the housing cavity, the length of the battery extends along the first direction, the length of the battery is 400 mm to 2500 mm, the thickness of the battery extends along a second direction perpendicular to the first direction, and the ratio of the length to the thickness of the battery is 5 to 250.

[0007] In some embodiments of the present application, the first electrode of one of two adjacent electrode sets and the second electrode of the other electrode set are electrically connected in series.

[0008] In some embodiments of the present application, the number of package films is one, and multiple electrode sets connected in series are packaged within the same package film. The connection point between the first electrode of one of the two electrode sets connected in series and the second electrode of the other electrode set is located within the package film.

[0009] In some embodiments of the present application, a package portion is formed relative to the package film and the first electrode and / or the second electrode, thereby dividing the package film into a plurality of housing cavities. At least one of the two adjacent electrode sets, the first electrode of one electrode set and the second electrode of the other electrode set, is located within the package portion.

[0010] In some embodiments of the present application, the number of package films is multiple, and each package film surrounds one independent housing cavity, at least one electrode set is packaged within one package film, and the first electrode and / or second electrode of at least one electrode set extends outside the package film.

[0011] In some embodiments of the present application, the air pressure between the metal case and the packaging film is lower than the air pressure outside the metal case.

[0012] In some embodiments of the present application, the atmospheric pressure P1 between the metal case and the packaging film is -100 kPa to -5 kPa.

[0013] In some embodiments of the present application, the atmospheric pressure P1 between the metal case and the packaging film is -75 kPa to -20 kPa.

[0014] In some embodiments of the present application, the relationship between the atmospheric pressure P1 between the metal case and the package film and the atmospheric pressure P2 inside the package film satisfies P1 > P2, and the range of P1 / P2 is 0.05 to 0.85.

[0015] In some embodiments of the present application, the value of P2 is between -100 kPa and -20 kPa.

[0016] In some embodiments of the present application, the metal case has two first surfaces facing each other along the second direction, the second direction being the thickness direction of the battery, and at least one of the first surfaces is recessed into the metal case.

[0017] In some embodiments of the present application, both of the first surfaces are recessed into the metal case to hold the electrode set.

[0018] In some embodiments of the present application, the number of recesses is multiple, and each recess is provided corresponding to one set of electrodes.

[0019] In some embodiments of the present application, the package film comprises a laminated nonmetallic outer film and a nonmetallic inner film, wherein the inner film is located between the electrode set and the outer film, the melting point of the outer film is greater than the melting point of the inner film, and the difference in melting points between the outer film and the inner film is between 30°C and 80°C.

[0020] In some embodiments of the present application, the material of the outer layer film is a combination of one or more of polyethylene terephthalate, polyamide, and polypropylene, and the material of the inner layer film is a combination of one or more of polypropylene, polyethylene, and polyethylene terephthalate.

[0021] In some embodiments of the present application, the outer layer film is bonded to the inner layer film.

[0022] In some embodiments of the present application, the adhesive is a polyolefin-based adhesive.

[0023] In some embodiments of the present application, the package film is an aluminum laminate film.

[0024] In some embodiments of the present application, the battery is substantially rectangular, and the thickness of the battery is greater than 10 mm.

[0025] In some embodiments of the present application, the thickness of the battery is 13 mm to 75 mm.

[0026] In some embodiments of the present application, the metal case includes a case body having an opening and a cover plate, the cover plate is hermetically connected to the opening of the case body, the electrode body sets are connected in series to form an electrode body row, both ends of the electrode body row have a first electrode and a second electrode respectively, and the first electrode and the second electrode are respectively drawn out from the cover plate.

[0027] In some embodiments of the present application, an air vent hole is provided in the metal case, and a sealing member is provided in the air vent hole.

[0028] In some embodiments of the present application, the thickness of the metal case is 0.05 mm to 1 mm.

[0029] The battery pack according to the second aspect of the present application includes a battery row including a plurality of batteries. The battery includes a sealed metal case, at least two sealed accommodation cavities located in the metal case, a plurality of electrode body sets, and a packaging film. The electrode body sets are arranged along a first direction, the electrode body sets are connected in series, the length of the electrode body sets extends along the first direction, the electrode body sets include an electrode body set main body, a first electrode and a second electrode for drawing out current, the first electrode and the second electrode are located on both sides of the electrode body set main body along the first direction respectively, at least one of the accommodation cavities is surrounded by the packaging film, the electrode body set main body is provided in the accommodation cavity, the length of the battery extends along the first direction, the length of the battery is 400 mm to 2500 mm, the thickness of the battery extends along a second direction perpendicular to the first direction, and the value of the ratio of the length to the thickness of the battery is 5 to 250.

[0030] In some embodiments of the present application, the thickness of the battery extends along a second direction, a plurality of the batteries are arranged in sequence along the second direction to form the battery row, there is a gap between at least two adjacent batteries, and the value range of the ratio of the gap to the thickness of the battery is 0.001 to 0.15.

[0031] In some embodiments of the present application, the metal case includes a case body and a cover plate having an opening, the cover plate being sealed to the opening of the case body, the gap between the two adjacent batteries including a first gap d1, the first gap being the minimum distance along the second direction between the two cover plates of the two adjacent batteries, the thickness of the batteries being the dimension of the cover plate along the second direction, and the range of the ratio of the first gap d1 to the thickness of the batteries being 0.005 to 0.1.

[0032] In some embodiments of the present application, the metal case has two first surfaces facing each other along the second direction, the gap between the two adjacent batteries includes a second gap d2, the second gap is the minimum distance between the two facing first surfaces of the two adjacent batteries, and the thickness of the batteries is the dimension of the cover plate along the second direction.

[0033] In some embodiments of the present application, the second gap d2 of the battery before use is greater than the second gap d2 of the battery after use.

[0034] In some embodiments of the present application, the battery pack further includes a battery pack cover and a tray, the battery pack cover and the tray being sealed together to form a battery housing chamber, the battery row being located within the battery housing chamber, the tray including a support member, the metal case having a support region, and the batteries being supported by the support member by contacting the support member through the support region.

[0035] In some embodiments of the present application, the tray includes side beams which are support members, and the battery is supported by the side beams at both ends along the first direction.

[0036] An electric vehicle relating to the third aspect of the present application includes a battery pack as described in any one of the above paragraphs.

[0037] Compared to the prior art, the beneficial effects of the present invention are as follows. In the battery of the present invention, the electrode set is packaged in a package film, and the electrode set packaged in the package film is then packaged in a metal case to perform secondary sealing. This allows for effective improvement of the sealing effect through the double-layer sealing action of the package film and the metal case. Furthermore, by arranging multiple electrode sets sequentially along the length of the battery, and aligning the length of the electrode sets with the length of the battery, and positioning the first and second electrodes of the electrode set on opposite sides of the electrode set along its length, the electrode sets are arranged in a "head-to-head" manner. This arrangement method makes it easy to connect two electrode sets in series.

[0038] Additional aspects and advantages of the present application are, in part, shown in the following description, in part, revealed in the following description, or as obtained through the practice of the present application. [Brief explanation of the drawing]

[0039] [Figure 1] This is a schematic diagram of the three-dimensional structure of the battery according to the embodiment of the present invention. [Figure 2] This is a schematic cross-sectional view of a battery according to an embodiment of the present invention. [Figure 3] This is a schematic diagram showing an electrode set according to an embodiment of the present application, packaged within a package film. [Figure 4] This is another schematic diagram showing the electrode set according to the embodiment of the present application packaged within a package film. [Figure 5] This is a schematic diagram showing a recess formed on the first surface of a metal case according to an embodiment of the present application. [Figure 6] This is a schematic diagram of the battery array according to an embodiment of the present invention. [Figure 7] This is a schematic diagram of the battery pack according to an embodiment of the present invention. [Figure 8] This is a schematic diagram of an electric vehicle according to an embodiment of the present invention. [Modes for carrying out the invention]

[0040] The embodiments of the present application will be described in detail below, and examples of the above embodiments are shown in the drawings. Throughout, the same or similar reference numerals indicate the same or similar parts or parts having the same or similar function. The embodiments described below with reference to the drawings are illustrative and are for interpretation purposes only, and should not be understood as limiting the present application.

[0041] Furthermore, in the description of this application, the directions or positional relationships indicated by terms such as "center," "vertical direction," "horizontal direction," "length," "width," "thickness," "top," "bottom," "front," "back," "left," "right," "perpendicular," "horizontal," "top," "bottom," "inside," "outside," "axial direction," "radial direction," and "circumferential direction" are based on the directions or positional relationships shown in the drawings and are merely for the purpose of easily explaining and simplifying the description of this application. They do not indicate or suggest that the shown device or component has a specific direction, or that it must be composed and operate in a specific direction, and therefore should not be understood as limiting this application.

[0042] As shown in Figures 1 to 5, the present invention provides a battery 100, for example, which refers to a battery that forms a battery pack. The battery 100 includes a sealed metal case 11, at least two sealed housing cavities located within the metal case 11, a plurality of electrode sets 12, and a packaging film 13.

[0043] The electrode sets 12 are connected in series, and each electrode set 12 includes at least one electrode.

[0044] The electrode set 12 includes a first electrode 121 and a second electrode 122 for drawing current. Furthermore, the electrode set 12 includes an electrode set body 123 and the first electrode 121 and second electrode 122 for drawing current. The first electrode 121 of one of two adjacent electrode sets 12 connected in series is connected in series to the second electrode 122 of the other electrode set 12. By connecting multiple electrode sets 12 in series, a single battery can achieve increased capacity and voltage, and reduce manufacturing processes and costs.

[0045] At least one housing cavity is surrounded by a package film 13, and the electrode body set main body 123 is provided inside the housing cavity.

[0046] In other words, the cavity walls of the housing cavity are made of the package film 13, and each electrode set 123 is located within the housing cavity, thus preventing interference between two adjacent electrode sets 12.

[0047] In this embodiment, the series connection method may involve adjacent electrode sets 12 being connected in series. Specifically, the first electrode 121 and the second electrode 122 of adjacent electrode sets may be directly connected, or an additional conductive member may be used to achieve the electrical connection. If the electrode set 12 contains only one electrode, the first electrode 121 and the second electrode 122 may be the positive electrode tab and the negative electrode tab of the electrode, respectively, or they may be the negative electrode tab and the positive electrode tab of the electrode. If the set contains multiple electrode bodies, the lead members of the first electrode 121 and the second electrode 122 may be electrode lead wires, or one of the first electrode 121 and the second electrode 122 may be a lead member formed by compound welding the positive electrode tabs of multiple electrode bodies, and the other may be a lead member formed by compound welding the negative electrode tabs of multiple electrode bodies. The terms "first" and "second" in "first electrode 121" and "second electrode 122" are used solely for distinguishing names and do not limit the number; for example, the first electrode 121 may be one or multiple.

[0048] The arrangement direction of the multiple electrode sets 12 is the first direction A, the length direction of the electrode sets 12 extends along the first direction A, and the length of the battery also extends along the first direction A. That is, the multiple electrode sets 12 are arranged sequentially along the length direction of the battery, and the first electrode 121 and the second electrode 122 of the electrode set 12 are located on both sides of the electrode set 12, respectively, along the first direction A. In other words, the multiple electrode sets 12 use a "head-to-head" arrangement method, and this arrangement method makes it easy to connect two electrode sets 12 in series, resulting in a simple connection structure. Furthermore, this arrangement method makes it easy to manufacture long batteries 100. As a result, when the batteries 100 are installed inside the battery pack case, there is no need to provide support structures such as horizontal and vertical beams. The batteries 100 can be directly attached to the battery pack case using the metal case 11 of the batteries 100 themselves as a support. This saves internal space in the battery pack, improves the volume utilization rate of the battery pack, and helps to reduce the weight of the battery pack.

[0049] The battery is approximately rectangular, and its length L is 400mm to 2500mm, and may be, for example, 500mm, 1000mm, or 1500mm. Compared to the conventional method of providing only one electrode, by providing multiple electrode sets 12 inside the battery, longer batteries can be manufactured more easily. In conventional batteries, as the length of the battery increases, the length of the internal copper-aluminum foil used as a current collector increases accordingly, significantly increasing the internal resistance of the battery, making it impossible to meet the increasingly high power and rapid charging requirements. When the length of the battery is the same, the embodiment of the present invention can significantly reduce the internal resistance of the battery, and can avoid problems such as battery overheating in the case of high power output and rapid charging.

[0050] The thickness D of battery 100 may be greater than 10 mm, and may be in the range of, for example, 13 mm to 75 mm. The thickness D of battery 100 extends along a second direction B perpendicular to a first direction A, and the ratio of the length L of battery 100 to the thickness D is between 5 and 250.

[0051] In the embodiment of the present invention, the electrode set 12 is packaged within a package film 13; that is, the package film 13 is further provided between the metal case 11 and the electrode set 12. This allows for secondary packaging of the electrode set 12 by the package film 13 and the metal case 11, which helps to improve the sealing effect of the battery. It should be understood that electrolyte is further injected into the package film 13. Therefore, this method further avoids contact between the electrolyte and the metal case 11, thereby preventing corrosion of the metal case 11 or decomposition of the electrolyte.

[0052] In the embodiment of the present invention, the air pressure between the metal case 11 and the package film 13 is lower than the air pressure outside the metal case 11.

[0053] In this application, "atmospheric pressure" is an abbreviation for atmospheric pressure. It refers to the pressure of a gas acting per unit area, that is, it is equal to the weight of a vertical column of air extending upward to the upper limit of the atmosphere per unit area.

[0054] The air pressure between the metal case 11 and the packaging film 13 is the air pressure in the space located between the metal case 11 and the packaging film 13, and this air pressure is lower than the air pressure outside the metal case 11. Therefore, in the embodiment of the present invention, since there is a negative pressure between the metal case 11 and the packaging film 13, when the metal case 11 is dented or deformed by atmospheric pressure, the gap between the metal case 11 and the electrode set 12 decreases accordingly, reducing the space in which the electrode set 12 can move or be displaced relative to each other. Furthermore, the movement of the electrode set 12 and the relative displacement of the electrode set 12 relative to each other can be reduced, improving the stability, strength, and safety performance of the battery 100.

[0055] For example, by performing an air release process on the space between the metal case 11 and the package film 13, a negative pressure state is created between the metal case 11 and the package film 13, bringing the metal case 11 as close as possible to the internal electrode set, reducing the internal gap, preventing the electrode bodies from moving within the metal case, and preventing relative displacement between the electrode bodies. This reduces the occurrence of situations such as damage to the current collector, wrinkled separators, and detachment of the active material layer, thereby improving the overall mechanical strength of the battery, extending the battery's lifespan, and enhancing the battery's safety performance.

[0056] In one embodiment, the atmospheric pressure between the metal case 11 and the packaging film 13 is P1, and the value of P1 may be -100 kPa to -5 kPa, or further, -75 kPa to -20 kPa. Of course, those skilled in the art can set the value of P1 according to their actual needs.

[0057] The air pressure inside the package film 13 is P2, and the relationship between P1 and P2 satisfies P1 > P2, and the range of P1 / P2 is 0.05 to 0.85.

[0058] The value of P2 may be between -100 kPa and -20 kPa.

[0059] The air pressure inside the packaging film 13 is lower than the air pressure between the metal case 11 and the packaging film 13.

[0060] By limiting P1, P2, and P1 / P2 to the above range, the electrode set 12 in this technology uses a secondary sealing mode. First, the electrode set 12 is packaged inside the package film 13. To avoid damage to the package film 13 due to excessively high internal pressure causing the package film 13 to bulge outward, the inventors select that the pressure between the metal case 11 and the package film 13 is greater than the pressure inside the package film 13. Furthermore, through numerous experiments, the inventors have verified that when P1 / P2 is within the above range, the reliability of the secondary sealing of the battery is well guaranteed, the interface between the battery electrodes is guaranteed, the gap between the electrodes is reduced, and lithium ions are conducted more efficiently.

[0061] In one embodiment of the present invention, there is one package film 13, or in other words, there is one package film 13, and multiple electrode sets 12 connected in series are packaged within the same package film 13, and each electrode set 12 includes an electrode set body 123 and a first electrode 121 and a second electrode 122 for drawing current, and the connection point between the first electrode 121 of one of the two electrode sets 12 connected in series and the second electrode 122 of the other electrode set 12 is located within the package film 13, that is, the package film 13 is provided integrally, and multiple electrode sets 12 are packaged within the same package film 13.

[0062] In actual applications, for example, as shown in Figure 3, first, multiple electrode sets 12 are connected in series, then a single package film 13 is used to wrap the series-connected electrode sets 12, for example, by placing the series-connected electrode sets 12 in a portion of the package film 13 (or by pre-grooving a portion of the package film 13 and then placing the series-connected electrode sets 12 in the groove), then another portion of the package film 13 is folded in the direction of the electrode sets 12, and then the two portions of the package film 13 are heat-sealed by a heat-sealing process, thereby packaging the series-connected electrode sets 12 within the same package film 13.

[0063] A package portion 131 is formed relative to the package film 13 and the first electrode 121 and / or second electrode 122, separating two adjacent electrode set bodies 123, and at least one of the first electrode 121 of one of the two adjacent electrode set bodies 12 and the second electrode 122 of the other electrode set body 12 is located within the package portion 131. The package portion 131 separates the multiple electrode set bodies, prevents the electrolyte from flowing between the multiple electrode set bodies, ensures that the multiple electrode set bodies 12 do not affect each other, and prevents the electrolyte in the multiple electrode set bodies 12 from decomposing due to a large potential difference, thereby guaranteeing the safety and service life of the battery.

[0064] The package portion 131 may have various embodiments. For example, the package portion 131 may be formed by fastening the package film 13 using cable ties, or the package portion 131 may be formed by directly heat-welding and connecting the package film 13. The specific method of forming the package portion 131 is not particularly limited.

[0065] In another embodiment of the present invention, as shown in Figure 4, there are multiple package films 13, i.e., the number of package films 13 is multiple, and at least one electrode set 12 is packaged in one package film 13, and the electrode assemblies are connected in series.

[0066] In other words, there is a one-to-one correspondence between the number of package films 13 and the number of electrode sets 12, and each electrode set 12 is packaged individually in one package film 13. In such an embodiment, after the manufacturing of multiple electrode sets 12 is complete, one package film 13 can be fitted individually onto the outside of each electrode set 12, and then the electrode assemblies can be connected in series.

[0067] At least one of the first electrode 121 and the second electrode 122 of the electrode assembly 12 extends outside the package film 13. For example, the first electrode 121 may extend outside the package film 13, the second electrode 122 may extend outside the package film 13, or both the first electrode 121 and the second electrode 122 may extend outside the package film 13. Because at least one of the first electrode 121 and / or the second electrode 122 extends outside the package film 13, the extended electrode can be connected in series to another electrode assembly.

[0068] Furthermore, the metal case 11 includes a case body 111 and a cover plate 112, each having an opening. The cover plate 112 is sealed to the opening of the case body 111. Multiple electrode sets 12 are connected in series to form an electrode row, each having a first electrode and a second electrode at both ends of the electrode row. The first electrode of the electrode row is the first electrode 121 of the electrode set 12 located at one end of the electrode row, and the second electrode of the electrode row is the second electrode 122 of the electrode set 12 located at the other end of the electrode row. The first and second electrodes of the electrode row are each extended from the cover plate 112.

[0069] In some embodiments, the case body 111 may have openings at both ends, and the number of cover plates 112 may be two, so that the two cover plates 112 are each sealed to the openings at both ends of the case body 111. In such a configuration, the first electrode and the second electrode of the electrode array may be drawn from the same cover plate 112, or they may each be drawn from two cover plates 112, and this is not limited to these configurations.

[0070] In some embodiments, the case body 111 may have an opening at only one end, and since there is only one cover plate 112, the one cover plate 112 is sealed to the opening at one end of the case body 111. In this configuration, the first and second electrodes of the electrode array are drawn out from the same cover plate 112.

[0071] In the embodiment of the present application, the thickness of the battery extends along a second direction B perpendicular to a first direction A, and the metal case 11 has two opposing first surfaces 113 along the second direction B, the first surfaces 113 being the largest surface of the battery 100, i.e., the "large surface" of the battery. At least one of the first surfaces 113 is recessed into the metal case 11 so that the metal case 11 and the electrode set 12 can be bonded together as much as possible.

[0072] Since the metal case 11 is a thin sheet with a small thickness, the depression 114 on the first surface 113 of the metal case 11 may be a depression formed, for example, when air is vented from inside the metal case 11. That is, when the air pressure between the metal case 11 and the package film 13 is lower than the air pressure outside the metal case 11 due to the air venting process performed on the space between the metal case 11 and the package film 13, the first surface 113 of the metal case 11 is likely to depression into the metal case 11 as the air venting progresses, forming the depression 114.

[0073] During normal use, batteries generally expand due to the expansion of the materials themselves and the generation of gases from the electrolyte. Typically, the area of ​​greatest expansion deformation is located on the larger surface of the battery. Using this technology, in the initial state of the battery, the larger surface is formed to slightly indent inward through vacuuming. This effectively alleviates the pressure between the batteries after expansion, improving the lifespan and safety performance of the battery and the entire system.

[0074] In some other embodiments, as shown in Figure 5, a recess 114 may be pre-formed on the first surface 113 of the metal case 11, and then an air venting process may be performed inside the metal case 11. There may be multiple recesses 114 on the first surface 113 of the metal case 11; for example, multiple recesses 114 may be pre-formed on the first surface 113, and the position of each recess 114 corresponds to the position where one electrode assembly is located.

[0075] In some embodiments, the two opposing first surfaces 113 of the metal case 11 are both recessed inward, and the recessed areas hold the electrode set 12.

[0076] The metal case 11 may be provided with air vents, and air may be vented from the space between the metal case 11 and the package film 13 through these air vents. Since it is necessary to seal the air vents, a sealing member is further provided inside the air vents to seal them. The sealing member may be, for example, a plug or a rubber member, but is not limited to these.

[0077] In some embodiments, a gap is provided between the electrode set 12 and the inner surface of the metal case 11 before air is vented from the metal case 11, and this gap facilitates the installation of the electrode set 12 inside the metal case 11. After air is vented from the metal case 11, the metal case 11 is pressed against the outer surface of the electrode set 12 along the second direction B, clamping the electrode set 12 and thereby reducing the space in which the electrode set moves inside the metal case, improving the safety performance of the battery.

[0078] In the embodiments of the present application, the metal case 11 has high strength and high heat dissipation effect, and the metal case 11 includes, but is not limited to, an aluminum case or a steel case.

[0079] In some embodiments, the thickness of the metal case 11 is 0.05 mm to 1 mm.

[0080] If the metal case 11 is too thick, it not only increases the weight of the battery 100 and reduces its capacity, but if the metal case 11 is too thick, atmospheric pressure will make it difficult for the metal case 11 to indent or deform towards the electrode set 12, preventing a reduction in the gap between the metal case 11 and the electrode set 12, and further preventing it from effectively performing its role in positioning the electrode set 12. Moreover, if the metal case 11 is too thick, it increases the cost of air venting, thus increasing manufacturing costs.

[0081] This invention not only guarantees the strength of the metal case 11 by limiting the thickness of the metal case 11 to the above range, but also does not reduce the capacity of the battery 100. Furthermore, under negative pressure conditions, the metal case 11 is more easily deformed, and by reducing the distance between the metal case 11 and the electrode set 12, the movement of the electrode set 12 inside the metal case 11 and the relative displacement of the electrode sets 12 themselves are reduced.

[0082] In the embodiment of the present invention, the package film 13 includes a laminated nonmetallic outer film and a nonmetallic inner film, the inner film being located between the outer film and the electrode set 12.

[0083] The inner layer film may be made of a material with high chemical stability, such as electrolyte corrosion resistance, for example, polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), or a combination of several of the above materials.

[0084] The outer layer film is a protective layer that can prevent the penetration of air, especially water vapor and oxygen. The outer layer film may be, for example, polyethylene terephthalate, polyamide (PA, Polyamide), or polypropylene, or a combination of several of the above materials.

[0085] In the package film 13 of this embodiment, since the melting point of the outer layer film is greater than that of the inner layer film, when heat-sealed, the outer layer film does not melt, and the inner layer film melts in a timely manner, thereby ensuring excellent sealing performance. Furthermore, the difference in melting points between the outer layer film and the inner layer film may be between 30°C and 80°C, for example, the difference in melting points between the two may be 50°C or 70°C, and the specific materials can be selected according to actual demands.

[0086] The non-metallic outer film and the non-metallic inner film are bonded together with an adhesive to form a composite film. For example, to form a composite film by bonding, the material of the outer film may be PP, the material of the inner film may be PET, and the adhesive used to bond them together may be, for example, a polyolefin-based adhesive.

[0087] In this embodiment, a package film is formed using a two-layer non-metallic film to package the electrode set. By using a non-metallic package film, the tensile strength and elongation at break are increased, and the limitations on the battery thickness are reduced, resulting in a thicker manufactured battery. The thickness of the battery in this embodiment has a wide expandable range, for example, greater than 10 mm, and may be in the range of 13 mm to 75 mm.

[0088] In some other embodiments of the present application, the packaging film may be an aluminum laminate film.

[0089] In one embodiment of the present invention, the battery is a lithium-ion battery.

[0090] In another embodiment of the present application, a battery module including the battery of any of the above embodiments is provided. By using the battery module according to the present application, high sealing performance, fewer assembly processes, and lower battery costs are achieved.

[0091] Referring to Figures 6 and 7, the present invention further provides a battery pack 200 including a battery array 21, the battery array 21 including a plurality of batteries 100, the batteries 100 being the batteries 100 described in any of the above embodiments, and therefore the specific structure of the batteries 100 will not be described here.

[0092] The battery array 21 may consist of one or more batteries, and each battery array 21 may contain one or more batteries 100. In actual manufacturing, the number of batteries 100 can be set according to actual demand, and the number of battery arrays 21 can also be set according to actual demand. This invention does not specifically limit these arrangements.

[0093] In the embodiment of the present application, the length of the battery 100 extends along a first direction A, and its thickness extends along a second direction B perpendicular to the first direction A. Multiple batteries 100 are arranged sequentially along the second direction B to form a battery row 21. There is a gap between at least two adjacent batteries 100, and the ratio of the gap to the thickness of the battery 100 is in the range of 0.001 to 0.15.

[0094] Furthermore, although the gap between two adjacent batteries changes as the battery operating time increases, as long as the ratio of the gap to the thickness between the batteries is within the range limited by this application, whether during operation, after operation, or before the batteries are shipped, it is within the scope of protection of this application.

[0095] In this invention, the certain gap left between the batteries 100 can serve as a buffer space in case the batteries 100 expand.

[0096] The expansion of battery 100 is related to the thickness of battery 100; the greater the thickness of the battery, the more easily it expands. This invention limits the ratio of the gap between batteries 100 to the thickness of battery 100 to 0.001 to 0.15, thereby making full use of the space in the battery pack 200, improving the utilization rate of the battery pack 200, and providing an excellent buffering effect against the expansion of battery 100.

[0097] Furthermore, since the batteries 100 generate heat when they expand, a certain gap is left between them, and this gap can function as a heat dissipation passage, such as an air duct. Because the heat dissipation effect is higher on the larger surface area of ​​the batteries 100, the heat dissipation efficiency of the battery pack 200 can be improved, and the safety performance of the battery pack 200 can be enhanced.

[0098] In the above solution, the gap between the batteries 100 can be understood as simply leaving a certain amount of space without any structural members being provided between the batteries 100, and further, it can be understood that the batteries 100 are separated by other structural members provided between them.

[0099] Furthermore, if a structural member is provided between the batteries 100, the gap between the batteries 100 should be understood as the distance between the batteries 100 on both sides of the structural member, rather than the distance between the structural member and the batteries 100.

[0100] Furthermore, a certain gap may be left between the structural member and the batteries 100 on both sides of the structural member, or they may be in direct contact. If the structural member is in direct contact with the batteries 100 on both sides, the structural member must have a certain degree of flexibility so that it can act as a buffer when the batteries 100 expand. The structural member includes, but is not limited to, aerogel, thermally conductive structural adhesive, or insulating cotton.

[0101] In this application, if there are multiple battery rows 21, the gap should refer to the distance between two adjacent batteries 100 in the same battery row 21, rather than the distance between two adjacent batteries in different battery rows 21. Furthermore, in the same battery row 21, a certain gap may be left between all pairs of adjacent batteries, or a certain gap may be left between some pairs of adjacent batteries.

[0102] In some embodiments, the gap between two adjacent batteries 100 includes a first gap d1, which is defined as the minimum distance along a second direction B between the two cover plates 112 of the two adjacent batteries, and the thickness of the battery 100 is the dimension of the cover plate 112 along the second direction B. The ratio of the first gap d1 to the thickness of the battery 100 is in the range of 0.005 to 0.1.

[0103] In the above embodiment, because the cover plate 112 has high strength, it is less likely to expand relative to the case body 111, and even if a chemical reaction occurs inside the battery 100 after it has been operating for a certain period of time, causing the battery 100 to expand and press against an adjacent battery 100, and the first gap d1 changes (for example, gradually increases), the degree of such change is small and can be ignored, or even if it changes, the value of the ratio of the first gap to the thickness of the battery 100 still satisfies the above range. In the above embodiment, if cover plates 112 are provided at both ends of the case body 111 and the batteries 100 are arranged in a battery row 21 along the thickness direction, the gap between two batteries 100 refers to the minimum distance between two cover plates 112 located at the same end of the battery row 21, rather than the distance between two cover plates 112 located at different ends of the battery 100.

[0104] In some embodiments, the gap between two adjacent batteries 100 includes a second gap d2, where the second gap d2 is the minimum distance between the two opposing first surfaces 113 of the two adjacent batteries 100. The second gap d2 before use of the batteries 100 is greater than the second gap d2 after use.

[0105] "Before use" can be understood as the state before the battery 100 is shipped after assembly is complete, or after it has been shipped but has not yet begun to supply power to an external source, and "after use" can be understood as the state after the battery 100 has supplied power to an external source. For example, if the battery pack 200 is assembled into an electric vehicle 1000, the "before use" state can be understood as the state of a new vehicle, and the "after use" state should be the state after the vehicle has traveled a certain distance.

[0106] In this embodiment, the second gap should refer to the minimum distance between the two opposing first surfaces of two adjacent batteries 100, the distance which gradually decreases with increasing battery usage time, mainly because the distance between the two adjacent large surfaces gradually decreases after the batteries have expanded.

[0107] In the embodiment of the present application, the battery pack 200 further includes a battery pack cover and a tray 22, the battery pack cover not shown in the graph of Figure 7. The battery pack cover and the tray 22 are sealed together to form a battery housing cavity, and the battery row 21 is located within the battery housing cavity. The tray 22 includes a support member 221, and a support area is formed on the metal case 11 of the battery 100, and the battery 100 is supported by the support member 221 by contacting the support area with the support member 221.

[0108] Furthermore, the tray 22 includes side beams which are support members 221, and the battery 100 is supported at both ends along the first direction A by the side beams.

[0109] In the battery 100 of the embodiment of the present invention, the air pressure between the metal case 11 and the package film 13 is negative pressure, which can improve the overall strength of the battery. As a result, the battery 100 can be supported by its own strength and directly attached to the tray 22. This eliminates the need to provide structures such as horizontal or vertical beams in the tray 22 to support the battery 100, which helps to improve the utilization rate of the internal space of the battery pack.

[0110] As shown in Figure 8, the electric vehicle 1000 includes the battery pack 200. Using the electric vehicle 1000 according to the present invention results in a vehicle with a long driving range and low cost.

[0111] In this description, unless otherwise clearly specified or limited, the terms "attachment," "connection," and "connection" should be understood in a broad sense. For example, a fixed connection, a detachable connection, or an integral connection may be a mechanical connection or an electrical connection, a direct connection or an indirect connection via an intermediate medium may be a connection between the internal parts of two components. A person skilled in the art will be able to understand the specific meaning of these terms in this application depending on the specific circumstances.

[0112] In this specification, any reference to terms such as "examples," "specific examples," or "examples" means that the specific features, structures, materials, or properties described in combination with such examples are included in at least one example of this application. In this specification, the exemplary expressions of the above terms are not necessarily limited to the same example or example. Furthermore, the specific features, structures, materials, or properties described may be appropriately combined in any one or more examples.

[0113] Although embodiments of this application have been described as examples, as will be understood by those skilled in the art, various changes, modifications, substitutions, and alterations can be made to these embodiments without departing from the principles and spirit of this application, and the scope of this application is limited by the claims and their equivalents. [Explanation of Symbols]

[0114] 100 batteries 11 Metal Case 12 electrode set 13. Package film 111 Case body 112 Cover Plate 113 First surface 114 depression, 121 First electrode 122 Second electrode 131 Packaging Section 200 Battery Pack 21 Battery row 22 trays 221 Support member L Battery length D. Battery thickness A First direction B. Second direction 1000 electric vehicles

Claims

1. Sealed metal case, A battery comprising at least two sealed housing cavities, a plurality of electrode sets, and a packaging film located within the aforementioned metal case, The aforementioned metal case seals the inside of the metal case, The electrode set is arranged along the first direction, The electrode set is connected in series, the length of the electrode set extends along the first direction, the electrode set includes an electrode set body, and a first electrode and a second electrode for drawing current, the first electrode and the second electrode are located on both sides of the electrode set body along the first direction, At least one of the housing cavities is surrounded by the package film, the electrode body set is placed inside the housing cavity, and the package film seals the inside of the package film. The length of the battery extends along the first direction, and the length of the battery is 400 mm to 2500 mm; the thickness of the battery extends along a second direction perpendicular to the first direction; and the ratio of the length to the thickness of the battery is 5 to 250. The air pressure between the metal case and the packaging film is lower than the air pressure outside the metal case. The atmospheric pressure P1 between the metal case and the packaging film is -75 kPa to -20 kPa. A battery characterized in that the relationship between the atmospheric pressure P1 between the metal case and the package film and the atmospheric pressure P2 inside the package film satisfies P1 > P2, and the range of P1 / P2 is 0.05 to 0.

85.

2. The battery according to claim 1, characterized in that the first electrode of one of the two adjacent electrode sets and the second electrode of the other electrode set are electrically connected in series.

3. The number of the aforementioned package film is one, and the multiple electrode sets connected in series are packaged within the same package film. The battery according to claim 1 or 2, characterized in that the connection point between the first electrode of one of the two electrode sets connected in series and the second electrode of the other electrode set is located within the package film.

4. A package portion is formed at the position of the package film corresponding to the first electrode and / or the second electrode, and the package film is divided into a plurality of the housing cavities. The battery according to claim 3, characterized in that at least one of the first electrode of one of the two adjacent electrode sets and the second electrode of the other electrode set is located in the package portion.

5. The battery according to any one of claims 1 to 4, characterized in that the number of package films is multiple, each package film surrounds one independent housing cavity, at least one electrode set is packaged within one package film, and the first electrode and / or second electrode of at least one electrode set extends outside the package film.

6. The battery according to claim 1, characterized in that the value of P2 is between -100 kPa and -20 kPa.

7. The battery according to any one of claims 1 to 6, wherein the metal case has two first surfaces facing each other along the second direction, and at least one of the first surfaces is recessed on the inner side of the metal case.

8. The battery according to claim 7, characterized in that both of the first surfaces are recessed into the inside of the metal case to hold the electrode set.

9. The battery according to claim 7 or 8, characterized in that the number of recesses is multiple, and each recess is provided corresponding to one electrode set.

10. The battery according to any one of claims 1 to 9, wherein the package film comprises a laminated nonmetallic outer layer film and a nonmetallic inner layer film, the inner layer film is located between the electrode set and the outer layer film, the melting point of the outer layer film is greater than the melting point of the inner layer film, and the range of the melting point difference between the outer layer film and the inner layer film is 30°C to 80°C.

11. The battery according to claim 10, characterized in that the material of the outer layer film is a combination of one or more types selected from polyethylene terephthalate, polyamide, and polypropylene, and the material of the inner layer film is a combination of one or more types selected from polypropylene, polyethylene, and polyethylene terephthalate.

12. The battery according to claim 10 or 11, characterized in that the outer layer film is bonded to the inner layer film.

13. The battery according to claim 12, characterized in that the adhesive used for bonding is a polyolefin-based adhesive.

14. The battery according to any one of claims 1 to 13, characterized in that the package film is an aluminum laminate film.

15. The battery according to any one of claims 1 to 14, characterized in that the battery is substantially rectangular and the thickness of the battery is greater than 10 mm.

16. The battery according to claim 15, characterized in that the thickness of the battery is 13 mm to 75 mm.

17. The battery according to any one of claims 1 to 16, wherein the metal case includes a case body having an opening and a cover plate, the cover plate is sealed and connected to the opening of the case body, the electrode set is connected in series to form an electrode row, and both ends of the electrode row have a first electrode and a second electrode, respectively, and the first electrode and the second electrode are each led out from the cover plate.

18. The battery according to claim 17, characterized in that the metal case is provided with air vents, and a sealing member is provided within the air vents.

19. The battery according to any one of claims 1 to 18, characterized in that the thickness of the metal case is 0.05 mm to 1 mm.

20. A battery pack including a battery array containing multiple batteries, The aforementioned battery has a sealed metal case, The metal case includes at least two sealed housing cavities, a plurality of electrode sets, and a packaging film, The aforementioned metal case seals the inside of the metal case, The electrode set is arranged along the first direction, The electrode set is connected in series, the length of the electrode set extends along a first direction, the electrode set includes an electrode set body, and a first electrode and a second electrode for drawing current, the first electrode and the second electrode are located on both sides of the electrode set body along the first direction, At least one of the housing cavities is surrounded by the package film, the electrode body set is provided within the housing cavity, and the package film seals the inside of the package film. The length of the battery extends along the first direction, and the length of the battery is 400 mm to 2500 mm; the thickness of the battery extends along a second direction perpendicular to the first direction; and the ratio of the length to the thickness of the battery is 5 to 250. The air pressure between the metal case and the packaging film is lower than the air pressure outside the metal case. The atmospheric pressure P1 between the metal case and the packaging film is -75 kPa to -20 kPa. A battery pack characterized in that the relationship between the atmospheric pressure P1 between the metal case and the package film and the atmospheric pressure P2 inside the package film satisfies P1 > P2, and the range of P1 / P2 is 0.05 to 0.

85.

21. The multiple batteries are arranged in order in the second direction to form the battery row. The battery pack according to claim 20, characterized in that there is a gap between at least two adjacent batteries, and the range of the ratio of the gap to the thickness of the batteries is 0.001 to 0.

15.

22. The metal case includes a case body having an opening and a cover plate, the cover plate being sealed and connected to the opening of the case body. The battery pack according to claim 21, characterized in that the gap between the two adjacent batteries includes a first gap d1, the first gap is the minimum distance along the second direction between the two cover plates of the two adjacent batteries, the thickness of the battery is the dimension of the cover plate along the second direction, and the range of the ratio of the first gap d1 to the thickness of the battery is 0.005 to 0.

1.

23. The metal case includes a case body having an opening and a cover plate, the cover plate being sealed and connected to the opening of the case body. The battery pack according to claim 21 or 22, characterized in that the metal case has two first surfaces facing each other along the second direction, the gap between the two adjacent batteries includes a second gap d2, the second gap is the minimum distance between the two facing first surfaces of the two adjacent batteries, and the thickness of the battery is the dimension of the cover plate along the second direction.

24. The battery pack according to claim 23, characterized in that the second gap d2 before use of the battery is larger than the second gap d2 after use.

25. The battery pack according to any one of claims 21 to 24, further comprising a battery pack cover and a tray, wherein the battery pack cover and the tray are sealed and connected to form a battery housing cavity, the battery row is located within the battery housing cavity, the tray includes a support member, a support region is formed in the metal case, and the batteries are in contact with the support member by the support region and supported by the support member.

26. The battery pack according to claim 25, characterized in that the tray includes a side beam which is a support member, and the battery is supported by the side beam at both ends along the first direction.

27. An electric vehicle characterized by including a battery pack according to any one of claims 20 to 26.

Images