Batteries, battery modules, battery packs, and electric vehicles

Abstract

The battery (100), battery module, battery pack (200), and electric vehicle include the battery (100) including a metal case (11), a packaging member, and a plurality of electrode body sets (12), the packaging member including two opposing packaging sections (13) and having an internal space, the two packaging sections (13) being joined at predetermined positions to divide the internal space of the packaging member into a plurality of sealed accommodating cavities, an electrode body set (12) being provided in at least one of the sealed accommodating cavities, and the metal case (11) being fitted to the outside of the packaging member.

Description

Technical Field

[0005] , ,

[0006] ,

[0001] (Cross - reference to related applications) This application claims the priority of Chinese Patent Application No. "202020064787.9" with the invention title of "Battery, Battery Module, Battery Pack and Electric Vehicle" filed by BYD Company Limited on January 13, 2020, and the priority of Chinese Patent Application No. "202021062203.0" with the invention title of "Battery, Battery Module, Battery Pack and Electric Vehicle" filed by BYD Company Limited on June 10, 2020.

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

Background Art

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

[0004] Since it is necessary to add electrolyte during the manufacturing process of the battery, it is necessary to seal the battery to prevent electrolyte leakage. 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. [[ID=​​​​​​​​To this end, a battery according to a first aspect of the present application includes a metal case, a package member, and a plurality of electrode sets, the package member includes two opposing package portions and has an internal space, the two package portions are joined at a predetermined position to partition the internal space of the package member into a plurality of sealed housing cavities, the electrode sets are provided in at least one of the sealed housing cavities, and the metal case is fitted to the outside of the package member.

[0007] In some embodiments of the present application, the package member is formed by folding a package film along a predetermined fold line, and the portions of the package film located on both sides of the fold line each constitute the two package portions.

[0008] In some embodiments of the present application, the two package portions are two package films.

[0009] In some embodiments of the present application, the cavity wall of the sealed housing cavity includes two side walls facing each other along the thickness direction of the battery, and at least one side wall of the sealed housing cavity recesses outward from the sealed housing cavity to form a groove, the groove housing the electrode set.

[0010] In some embodiments of the present application, the two package portions are joined together by thermal melting at a predetermined position.

[0011] In some embodiments of the present application, the battery includes a first direction, the plurality of electrode sets are arranged along the first direction, and the electrode sets include a first electrode and a second electrode, respectively, located on either side of the electrode set along the first direction.

[0012] In some embodiments of the present application, 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 embedded in the corresponding junction position of the two package portions.

[0013] In some embodiments of the present application, the air pressure inside the sealed containment cavity is lower than the air pressure between the metal case and the package member.

[0014] In some embodiments of the present application, the air pressure between the metal case and the package member is lower than the air pressure outside the metal case.

[0015] In some embodiments of the present application, the atmospheric pressure P1 between the metal case and the package member is -100 kPa to -5 kPa.

[0016] In some embodiments of the present application, the atmospheric pressure in the sealed containment cavity is P2, the relationship between P1 and P2 satisfies P1 > P2, and the range of P1 / P2 is 0.05 to 0.85.

[0017] In some embodiments of the present application, the value of P2 is between -100 kPa and -20 kPa.

[0018] In some embodiments of the present application, the battery includes a first direction, the plurality of electrode sets are arranged along the first direction, the length of the electrode sets extends along the first direction, the length of the battery extends along the first direction, and the length of the battery is 400 mm to 2500 mm.

[0019] In some embodiments of the present application, the thickness of the battery extends along a second direction, the metal case has two first surfaces facing each other along the second direction, and at least one of the first surfaces is recessed into the interior of the metal case.

[0020] In some embodiments of the present application, both of the two first surfaces are recessed inside the metal case to sandwich the electrode body set.

[0021] In some embodiments of the present application, the battery is substantially rectangular parallelepiped, and the thickness of the battery is greater than 10 mm.

[0022] In some embodiments of the present application, the ratio of the length to the thickness of the battery is 5 to 250.

[0023] 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.

[0024] In some embodiments of the present application, the wall thickness of the metal case is 0.05 mm to 1 mm.

[0025] The battery module according to the second aspect of the present application includes the battery according to any of the above embodiments.

[0026] The battery pack according to the third aspect of the present application includes a battery string including a plurality of batteries. The battery includes a metal case, a package member, and a plurality of electrode body sets. The package member includes two package parts provided opposite to each other. The two package parts are joined at a predetermined position to partition the internal space of the package member into a plurality of sealed accommodation cavities, and an electrode body set is provided in at least one of the sealed accommodation cavities. The metal case is fitted outside the package member.

[0027] In some embodiments of the present application, the thickness of the battery extends along a second direction, and the plurality of batteries are arranged in sequence along the second direction to form the battery string. There is a gap between at least two adjacent batteries, and the ratio range of the gap to the thickness of the battery is 0.001 to 0.15.

[0028] In some embodiments of the present application, the metal case includes a case body having an opening and a cover plate, and the cover plate is sealingly connected to the opening of the case body to seal the internal space of the case body. The gap includes a first gap d1, and the first gap d1 is the minimum distance along the second direction between two cover plates of two adjacent batteries. The thickness of the battery is the dimension of the cover plate along the second direction, and the ratio range between the first gap d1 and the thickness of the battery is 0.005 to 0.1.

[0029] In some embodiments of the present application, the metal case includes a case body having an opening and a cover plate, and the cover plate is sealingly connected to the opening of the case body to seal the internal space of the case body. The battery has two first surfaces facing each other along a second direction, and the gap between two adjacent batteries includes a second gap d2. The second gap d2 is the minimum distance between two first surfaces of two adjacent batteries facing each other. The thickness of the battery is the dimension of the cover plate along the second direction.

[0030] In some embodiments of the present application, the first gap d1 before use of the battery is larger than the second gap d2 after use.

[0031] The electric vehicle according to the fourth aspect of the present application includes the battery pack according to any one of the above embodiments.

[0032] Compared to conventional technology, the beneficial effects of the present invention are as follows. First, in the battery of the present invention, the electrode set is packaged within a package member, and then a metal case is fitted to the outside of the package member to perform secondary sealing. This double-layer sealing action of the package member and the metal case effectively improves the sealing effect. Second, the package member has multiple sealed housing cavities, separating two adjacent electrode sets. This prevents the electrolyte from flowing between the electrode sets. In this way, the electrode sets do not affect each other, and the electrolyte in the electrode sets does not decompose due to a large potential difference. Furthermore, since the two package films are joined at predetermined positions and formed as a single unit, the manufacturing process is greatly reduced, manufacturing efficiency is improved, and the battery is more suitable for automated work. Furthermore, by packaging multiple electrode sets within a single metal case, longer batteries can be manufactured more easily. As a result, longer and stronger batteries can be easily manufactured using the solution of this invention. When the batteries are installed in the battery pack case, the installation of support structures such as horizontal and vertical beams within the battery pack is reduced, and the batteries themselves can be directly attached to the battery pack case as 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.

[0033] Additional aspects and advantages of the present application are, in part, shown in the following description, in part, become apparent in the following description, or are understood through the practice of the present application. [Brief explanation of the drawing]

[0034] [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] Figure 1 is a schematic cross-sectional view of the battery. [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 a schematic diagram showing a recess formed on the first surface of a metal case according to an embodiment of the present application. [Figure 5] This is a schematic diagram of the battery array according to an embodiment of the present invention. [Figure 6] This is a schematic diagram of the battery pack according to an embodiment of the present invention. [Figure 7] This is a schematic diagram of a package member formed from an integrally molded package film, in which a groove is provided in one package portion, according to an embodiment of the present application. [Figure 8] This is a schematic diagram of a package member formed from an integrally molded package film, in which grooves are provided in two package portions, according to an embodiment of the present application. [Figure 9] This is a schematic diagram illustrating the relationship between the battery module and the battery according to an embodiment of the present invention. [Figure 10] This is a schematic diagram illustrating the relationship between an electric vehicle and a battery pack according to an embodiment of the present invention. [Modes for carrying out the invention]

[0035] 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.

[0036] 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.

[0037] As shown in Figures 1 to 5, the battery 100 according to the present invention includes a metal case 11, a package member 15, and a plurality of electrode set 12, each electrode set 12 including at least one electrode, the package member 15 includes two opposing package sections 13 and has an internal space, the two package sections 13 are joined at a predetermined position to partition the internal space of the package member 15 into a plurality of sealed housing cavities 16, the electrode set 12 is provided in at least one sealed housing cavity 16, and the metal case 11 is fitted to the outside of the package member 15.

[0038] In this application, the electrode body referred to is a common electrode body in the field of power batteries, and the electrode body and electrode body set 12 are components inside the case of the battery 100 and should not be understood as the battery 100 itself. The battery 100 is a single cell, and the electrode body in this application may be an electrode body formed by winding or an electrode body manufactured by a lamination method, and generally the electrode body includes at least a positive electrode plate, a separator and a negative electrode plate. Furthermore, the battery 100 referred to in this application is an independent single cell and includes multiple electrode bodies, so it should not be easily understood as a battery module 300 or a battery pack.

[0039] The battery 100 in this application may be a liquid-type battery, that is, an electrode body containing an electrolyte, or it may be a solid-state battery, with the electrode body containing a solid electrolyte or a gel polymer electrolyte.

[0040] In this application, the electrode set 12 may consist of one independent electrode, or it may include at least two electrode bodies, and at least two electrode bodies may be connected in parallel to constitute the electrode set 12. For example, two electrode bodies may be connected in parallel to constitute the electrode set 12, or four electrode bodies may be connected in parallel to constitute the electrode set 12.

[0041] The "predetermined location" can be understood as the space between two adjacent electrode sets 12 and the outer edges of the two package portions 13, and the number of sealed housing cavities 16 is not limited and may be two, three or more.

[0042] Multiple electrode sets 12 may be connected in series or in parallel.

[0043] By the above technical means, in the battery 100 of the present invention, the electrode set 12 is packaged inside the package member 15, and then a metal case 11 is fitted to the outside of the package member 15 to perform secondary sealing. This effectively improves the sealing effect through the double-layer sealing action of the package member 15 and the metal case 11. The package member 15 is divided into a plurality of sealed housing cavities 16, separating two adjacent electrode sets 12. This prevents the electrolyte between the electrode sets 12 from flowing to each other. In this way, the electrode sets 12 do not affect each other, and the electrolyte in the electrode sets 12 does not decompose due to a large potential difference. Furthermore, multiple electrode sets are contained within a single metal case 11. By packaging the electrode set 12, the long battery 100 can be manufactured more easily. Thus, the solution of the present invention makes it easy to manufacture the long battery 100, and when the battery 100 is installed inside the case of the battery pack 200, the battery 100 itself can be used as a horizontal or vertical beam, further reducing the need to install additional support structures such as horizontal and vertical beams inside the case of the battery pack 200. The battery 100 can be directly installed inside the case of the battery pack 200 using the battery 100 itself as a support, thereby saving internal space in the battery pack 200, improving the volume utilization rate of the battery pack 200, and helping to reduce the weight of the battery pack 200.

[0044] In some embodiments, the two package portions 13 are integrally formed, and as shown in Figures 7 and 8, the package member 15 is folded in the middle along a predetermined fold line by an integrally molded package film 17, and the portions located on both sides of the fold line of the package film 17 each constitute the two package portions 13.

[0045] Since the package component 15 is formed by folding a single package film 17 in the middle, the joining process between the two package components 13 can be omitted, thereby saving process and manufacturing costs.

[0046] In other embodiments, the two package portions 13 may be provided separately, and the package member 15 includes two opposing package films 17, each package film 17 constituting a package portion 13.

[0047] Each sealed housing cavity 16 may contain one electrode set 12, or multiple electrode sets 12.

[0048] In some embodiments of the present application, at least one package film 17 is provided with grooves 141 for accommodating a plurality of electrode sets 12.

[0049] In this embodiment, grooves 141 may be provided on both of the two package films 17, or grooves 141 may be provided on only one of the package films 17. If grooves 141 are provided on both of the package films 17, as shown in Figure 8, the grooves 141 on the two package films 17 may be facing each other, or the grooves 141 on the two package films 17 may be spaced apart.

[0050] The specific method for joining the two package films 17 at a predetermined position is not limited. For example, the two package films 17 may be joined by heat melting at the joining position 131, or they may be integrally bound at the joining position 131 with cable ties.

[0051] In some embodiments of the present application, the cavity wall of a sealed housing cavity 16 includes two side walls that are opposite to each other along the thickness direction of the battery 100, and at least one side wall of at least one sealed housing cavity 16 recesses outward from the sealed housing cavity 16 to form a groove 141 for housing an electrode set 12.

[0052] In the above embodiment, the two package portions 13 constitute two side walls that are provided opposite to each other along the thickness direction of the battery 100 in the sealed housing cavity 16, and at least one package portion 13 recesses outward from the sealed housing cavity 16 to form a groove 141 that can provide a housing space for the electrode set 12.

[0053] One or more grooves 141 may be formed in the cavity wall of the sealed housing cavity 16, and each groove 141 can accommodate one or more electrode sets 12.

[0054] In this embodiment, both package portions 13 may be recessed to the outside of the sealed housing cavity 16 to form a groove 141 for housing the electrode set 12, or one package portion 13 may be recessed to form a groove 141 for housing the electrode set 12, and the other package portion 13 may not have a groove 141, and if grooves 141 are formed in both package portions 13, as shown in Figure 8, the grooves 141 formed in the two package portions 13 may be opposite each other or spaced apart.

[0055] The specific method for joining the two package portions 13 at a predetermined position is not limited, and the two package portions 13 can be integrally bound at the joining position with a cable tie. In some embodiments, for example, if the package member 15 is a package film 17, the joining position of the package film 17 can be heated and melted, and then integrally pressed together, without requiring any other parts, and the inside of the package member 15 can be divided into multiple sealed containment cavities 16, making the manufacturing process simpler.

[0056] In the battery 100 of this application, the electrode set 12 is packaged within a package film 17, and a metal case 11 is further fitted to the outside of the package film to perform secondary sealing. This double-layer sealing action of the package film 17 and the metal case 11 effectively improves the sealing effect. The package film 17 is a single film and has multiple sealed housing cavities, which separates two adjacent electrode sets 12 and prevents the electrolyte from flowing between the electrode sets 12. In this way, the electrode sets 12 do not affect each other, and the electrolyte in the electrode sets 12 does not have a large potential difference. Since it does not require disassembly and multiple electrode sets 12 are packaged within a single metal case 11, a long battery 100 can be manufactured more easily. Therefore, the solution of the present invention makes it possible to easily manufacture longer and stronger batteries. As a result, when the battery is installed in the battery pack case, the installation of support structures such as horizontal and vertical beams within the battery pack is reduced, and the battery can be directly attached to the battery pack case using the battery itself 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.

[0057] In the above embodiment, the electrolyte may be injected before the two package portions 13 are completely joined, without providing a separate liquid inlet in the package member 15; or a separate liquid inlet may be provided in the package member 15; or the electrolyte may be injected through a separately provided liquid inlet after the two package portions 13 have been joined at a predetermined position.

[0058] The electrode set 12 includes a first electrode 121 and a second electrode 122. Furthermore, the electrode set 12 includes an electrode set body 123 and the first electrode 121 and second electrode 122 which are electrically connected to the electrode set body 123 to draw current. The first electrode 121 of one of the two electrode sets 12 connected in series is connected to the second electrode of the other electrode set 12. By connecting multiple electrode sets 12 in series, the capacity and voltage can be increased with a single battery, and the manufacturing process and cost can be reduced.

[0059] In some embodiments, the connection point between the first electrode 121 of one electrode set 12 and the second electrode 122 of the other electrode set 12, which are connected in series, is embedded in the corresponding junction position 131 of the two package portions 13. This prevents corrosion of the connection point between the first electrode 121 and the second electrode 122 by the electrolyte.

[0060] In actual applications, for example, as shown in Figures 3, 7, and 8, multiple electrode sets 12 are first connected in series, then a single package film 17 is used to wrap the series-connected electrode sets 12, for example, the series-connected electrode sets 12 are placed in a portion of the package film 17 (or grooves 141 are pre-made in a portion of the package film 17, and then the multiple series-connected electrode sets 12 are placed in the grooves 141), then another portion of the package film 17 is folded in the direction of the electrode sets 12, and then the two portions of the package film 17 are heat-fused and joined by a heat melting process, thereby packaging the series-connected electrode sets 12 within the same package film 17.

[0061] Two package sections 13 are joined at relative positions to the first electrode 121 and / or the 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 joining position 131. In this embodiment, multiple electrode set bodies 123 are separated, preventing the electrolyte from flowing between the multiple electrode set bodies 12, the multiple electrode set bodies 12 do not affect each other, and the electrolyte in the multiple electrode set bodies 12 does not decompose due to a large potential difference, thereby ensuring the safety and service life of the battery 100.

[0062] 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 12 may be directly connected, or an additional conductive member may be used to achieve the electrical connection. When 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. When the electrode set 12 contains multiple electrode bodies, the first electrode 121 may be a lead member formed by compound welding the positive electrode tabs of multiple electrode bodies, and the second electrode 122 may be a lead member formed by compound welding the negative electrode tabs of multiple electrode bodies. Alternatively, the first electrode 121 may be a lead member formed by compound welding the negative electrode tabs of multiple electrode bodies, and the second electrode 122 may be a lead member formed by compound welding the positive 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.

[0063] The metal case 11 includes a case body 111 having an opening and a cover plate 112. The cover plate 112 is sealed to the opening of the case body 11, sealing the internal space of the case body 11, and the plurality of electrode sets 12 are located in this internal space. The plurality of electrode sets 12 are connected in series to form an electrode row, and both ends of the electrode row include a first electrode 121 and a second electrode 122, respectively. The first electrode 121 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 122 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 electrode 121 and the second electrode 122 of the electrode row are each drawn out from the cover plate 112.

[0064] In one embodiment, two cover plates 112 are provided, located at opposite ends of the case body 111 to seal the internal space of the case body 111, and the first electrode 121 and the second electrode 122 are drawn out from the same cover plate 112. In another embodiment, the first electrode 121 is drawn out from one cover plate 112, and the second electrode 122 is drawn out from the other cover plate 112.

[0065] In other words, the case body 111 may have openings at both ends, and there may be two cover plates 112. The two cover plates 112 are sealed by being connected to the openings at both ends of the case body 111, thereby sealing the internal space of the case body 111. In this configuration, the first electrode 121 and the second electrode 122 of the electrode array may be drawn from the same cover plate 112, or they may be drawn from two separate cover plates 112; this is not a limitation.

[0066] 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 and connected to the opening at one end of the case body 111. In this configuration, the first electrode 121 and the second electrode 122 of the electrode array are drawn from the same cover plate 112.

[0067] In the embodiment of the present invention, the electrode set 12 is packaged within a package member 15, that is, the package member 15 is further provided between the metal case 11 and the electrode set 12. The package member 15 and the metal case 11 provide secondary packaging for the electrode set 12, which helps to improve the sealing effect of the battery 100. It should be understood that electrolyte is further injected into the package member 15. 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.

[0068] In some embodiments, the air pressure inside the sealed containment cavity 16 is lower than the air pressure between the metal case 11 and the package member 15. This makes the bond between the package member 15 and the electrode set 12 tighter and improves the strength of the electrode set 12.

[0069] In another embodiment, the air pressure between the metal case 11 and the package member 15 is lower than the air pressure outside the metal case 11.

[0070] 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.

[0071] In the battery manufacturing process, in order to facilitate the insertion of the electrode set 12 into the metal case 11, the distance between the two inner walls facing the metal case 11 is greater than the thickness of the electrode set 12. After the electrode set 12 is inserted into the metal case 11, a certain gap remains between the electrode set 12 and the inner wall of the metal case 11. As a result, the electrode set 12 does not make sufficient contact with the inner wall of the metal case 11, and the electrode set 12 moves easily inside the metal case 11. This can lead to problems such as damage to the current collector, wrinkles in the separator, and detachment of the active material, thereby reducing the stability of the battery.

[0072] Based on this, the present invention defines the air pressure between the metal case 11 and the package member 15, that is, the air pressure located in the space between the metal case 11 and the package member 15, and that this air pressure is lower than the air pressure outside the metal case 11, that is, there is a negative pressure state between the metal case 11 and the package member 15, the metal case 11 will sink or deform under the action of the pressure difference between the inside and outside, the gap between the metal case 11 and the electrode set 12 will decrease accordingly, the space in which the electrode set 12 moves or is displaced from one another will decrease, and further the movement of the electrode set 12 and the relative displacement of the electrode set 12 can be reduced, thereby improving the stability, strength and safety performance of the battery 100.

[0073] For example, by performing an air venting process in the space between the metal case 11 and the package member 15, a negative pressure state is created in the space between the metal case 11 and the package member 15. This brings the metal case 11 as close as possible to the electrode set 12 located inside it, reducing the internal void and preventing the electrode set 12 from moving within the metal case 11. It also prevents relative displacement between the electrode sets 12, thereby reducing the occurrence of situations such as damage to the current collector, wrinkled separators, and detachment of active materials. This improves the overall mechanical strength of the battery 100, extends the service life of the battery 100, and enhances the safety performance of the battery 100.

[0074] In one embodiment, the range of the atmospheric pressure P1 between the metal case 11 and the package member 15 may be -100 kPa to -5 kPa, and in one embodiment, the value of P1 may be -75 kPa to -20 kPa. Of course, those skilled in the art can set the value of P1 according to their actual needs.

[0075] In some embodiments, the atmospheric pressure inside the sealed containment cavity 16 is P2, the relationship between P1 and P2 satisfies P1 > P2, and the range of P1 / P2 is 0.05 to 0.85.

[0076] In one embodiment, the range of the P2 value is -100 kPa to -20 kPa.

[0077] The electrode set 12 in this application employs a secondary sealing mode. First, the electrode set 12 is packaged within the package member 15. To avoid the problem of damage to the package member 15 due to excessively high internal pressure causing it to bulge outward, the pressure between the metal case 11 and the package member 15 is specified to be greater than the pressure inside the package member 15. At the same time, the applicant of this application has verified through numerous experiments that limiting P1, P2, and P1 / P2 within the above ranges ensures the reliability of the secondary sealing of the battery 100, guarantees the interface between the electrode plates of the battery 100, reduces the gap between the electrode plates, and improves lithium ion conduction.

[0078] In the embodiment of the present invention, the arrangement direction of the plurality of 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 100 also extends along the first direction A. That is, the plurality of electrode sets 12 are arranged sequentially along the length direction of the battery 100, and the first electrode 121 and the second electrode 122 of the electrode sets 12 are located on both sides of the electrode set 12 along the first direction A. That is, the plurality of 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 a long battery 100, thereby making the battery 100 a battery pack When installed inside the case of the 200, there is no need to provide support structures such as horizontal and vertical beams. The battery 100 can be directly attached to the case of the battery pack 200 using the metal case 11 of the battery 100 itself as a support. This saves internal space in the battery pack 200, improves the volume utilization rate of the battery pack 200, and helps to reduce the weight of the battery pack 200.

[0079] Compared to conventional methods that use only one electrode, providing multiple electrode sets 12 within the battery makes it easier to manufacture longer batteries. In conventional batteries, as the battery length increases, the length of the internal copper-aluminum foil used as a current collector increases accordingly, significantly increasing the internal resistance of the battery and making it impossible to meet the increasingly high power and rapid charging requirements. When the battery length is the same, the embodiment of the present invention significantly reduces the internal resistance of the battery, thus avoiding problems such as battery overheating in the case of high power output and rapid charging.

[0080] Battery 100 is approximately a rectangular prism, and its length L is 400mm to 2500mm, and may be, for example, 500mm, 1000mm, or 1500mm.

[0081] The thickness D of the battery 100 may be greater than 10 mm, and may be in the range of, for example, 13 mm to 75 mm.

[0082] In the embodiment of the present invention, the ratio of the length to the thickness of the battery 100 is 5 to 250.

[0083] In the embodiment of the present application, the thickness of the battery 100 extends along a second direction B perpendicular to a first direction A, and the metal case 11 has two first surfaces 113 facing each other along the second direction B, the first surfaces 113 being the largest surface area of ​​the battery 100, i.e., the “large surface area” of the battery 100. At least one of the first surfaces 113 is recessed into the interior of the metal case 11 so that the metal case 11 and the electrode set 12 can be bonded together as much as possible.

[0084] Since the metal case 11 is a thin sheet with a small thickness, the recess 114 on the first surface 113 of the metal case 11 may be a recess 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 member 15 is lower than the air pressure outside the metal case 11 due to the air venting process in the space between the metal case 11 and the package member 15, the first surface 113 of the metal case 11 is likely to sink into the metal case 11 as the air venting progresses, forming a recess 114.

[0085] 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 the technology of this invention, in the initial state of the battery, the larger surface is formed to be slightly recessed inward by vacuuming, effectively alleviating the pressure between the batteries after expansion and improving the service life, safety performance, etc., of the battery and the entire system.

[0086] In some other embodiments, as shown in Figure 4, recesses 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 corresponds to the position where one electrode set 12 is located.

[0087] 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.

[0088] The metal case 11 is provided with an air vent, which allows for air to be vented from the space between the metal case 11 and the package member. Since the air vent needs to be sealed, a sealing member is further provided inside the air vent to seal it. The sealing member may be a plug, a rubber member, or the like, and is not limited to these.

[0089] 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 a second direction, clamping the electrode set 12, thereby reducing the space in which the electrode set 12 can move inside the metal case 11 and improving the safety performance of the battery 100.

[0090] 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.

[0091] In some embodiments, the thickness of the metal case 11 is 0.05 mm to 1 mm.

[0092] 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 makes it difficult for the metal case 11 to indent or deform towards the electrode set 12, preventing the gap between the metal case 11 and the electrode set 12 from being reduced, and further preventing it from effectively performing its role in positioning the electrode set 12. Moreover, if the metal case 11 is too thick, the cost of air venting increases, thus increasing manufacturing costs.

[0093] This invention not only guarantees the strength of the metal case 11 by limiting the thickness of the metal case 11 within the above range, but also does not reduce the capacity of the battery 100. Under negative pressure, the metal case 11 is more easily deformed, and by limiting the thickness of the metal case 11 within the above range, the distance between the metal case 11 and the electrode set 12 can be further reduced, thereby reducing the movement of the electrode set 12 inside the metal case 11 and the relative displacement of the electrode sets 12 themselves.

[0094] In the embodiment of the present invention, the package film 17 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.

[0095] 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.

[0096] 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.

[0097] In the package film 17 of this embodiment, since the melting point of the outer layer film is greater than that of the inner layer film, when sealed by thermal melting, the outer layer film does not melt, and the inner layer film melts in a timely manner, thereby ensuring excellent sealing performance. In one embodiment, 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 requirements.

[0098] 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.

[0099] In this embodiment, a package film 17 is formed using a two-layer nonmetallic film to package the electrode set 12. By using a nonmetallic package film 17, the tensile strength and elongation at break are increased, and the limitations on the thickness of the battery 100 are reduced, so the manufactured battery 100 can be thicker. The thickness of the battery 100 in this embodiment has a large expandable range, for example, greater than 10 mm, and may be in the range of 13 mm to 75 mm.

[0100] In some embodiments of the present application, the package film 17 is an aluminum laminate film.

[0101] In one embodiment of the present invention, the battery is a lithium-ion battery.

[0102] A battery module 300 according to another embodiment of the present invention includes the battery 100 of any of the embodiments described above. By using the battery module 300 according to the present invention, high sealing performance, fewer assembly processes, and lower battery 100 costs are achieved.

[0103] 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.

[0104] 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 needs. This invention does not specifically limit these arrangements.

[0105] 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 range of the gap to the thickness of the battery 100 is 0.001 to 0.15.

[0106] Although the gap between two adjacent batteries 100 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.

[0107] In this invention, the certain gap left between the batteries 100 can serve as a buffer space in case the batteries 100 expand.

[0108] The expansion of battery 100 is related to its thickness; the greater the thickness of battery 100, 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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 100 in different battery rows 21. Furthermore, within the same battery row 21, a certain gap may be left between all pairs of adjacent batteries 100, or a certain gap may be left between some pairs of adjacent batteries 100.

[0114] In one embodiment, 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 100, and the thickness of the battery 100 is the dimension of the cover plate 112 along the second direction B. The ratio range of the first gap d1 to the thickness of the battery 100 is 0.005 to 0.1.

[0115] Furthermore, if the battery 100 has two cover plates 1011, the first gap d1 for a given battery row 21 is the minimum distance along the second direction B between the two cover plates 1011 located on the same side of the two adjacent batteries 100.

[0116] If a battery 100 has only one cover plate 1011, and with respect to a battery row 21, the cover plates of two adjacent batteries 100 are located on the same side, then the first gap d1 is the minimum distance along the second direction B between the two cover plates 1011 located on the same side of the two adjacent batteries 100.

[0117] If a battery 100 has only one cover plate 1011, and the cover plates 1011 of two adjacent batteries 100 are located on different sides with respect to a certain battery row 21, it cannot be understood that the first gap d1 is the minimum distance along the second direction B of the two cover plates 1011 of the two adjacent batteries 100, and that the first gap d1 is the minimum distance along the first direction A of the two cover plates 1011 of the two adjacent batteries 100.

[0118] The "minimum distance along the second direction B" can be understood as the projection distance along the second direction B of the cover plates 1011 of two adjacent batteries 100. Alternatively, it can be understood as the distance between adjacent surfaces of the two cover plates 1011, and the "distance between adjacent surfaces" is the distance between the adjacent surfaces of the cover plates 1011 of two adjacent batteries 100.

[0119] 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 ratio of the first gap d1 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.

[0120] In one embodiment, the gap between two adjacent batteries 100 includes a second gap d2, the second gap d2 being the minimum distance between the two opposing first surfaces 113 of the two adjacent batteries 100. The first gap d1 before use of the batteries 100 is greater than the second gap d2 after use.

[0121] "Before use" can be understood as the state before the battery 100 is shipped after assembly is complete or before it begins supplying power to an external source, while "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 400, 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.

[0122] In this embodiment, the second gap should refer to the minimum distance between the two opposing first surfaces 113 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.

[0123] In the embodiment of the present application, the battery pack 200 further includes a battery cover and a tray 22, the battery cover not shown in the graph of Figure 7. The battery 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.

[0124] In one embodiment, the tray 22 includes a side beam which is a support member 221, and the battery 100 is supported at both ends along its length by the side beam.

[0125] In the battery 100 of the embodiment of the present invention, the air pressure between the metal case 11 and the package member 15 is negative pressure, which can improve the overall strength of the battery 100. 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 200.

[0126] The electric vehicle 400 includes the battery pack 200 described above. Using the electric vehicle 400 according to this application provides a long driving range and low cost.

[0127] 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.

[0128] 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.

[0129] 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]

[0130] 100 batteries 11 Metal Case 12 electrode set 13. Packaging section 141 Groove 15. Packaging components 16 Sealed containment cavity 17. Packaging film 111 Case body 112 Cover Plate 113 First surface 114 recess 121 First electrode 122 Second electrode 123 Electrode body set main unit 131 Joint position 200 Battery Pack 300 Battery Modules 400 Electric Vehicles 21 Battery row 22 trays 221 Support member L Battery length D Battery thickness A First direction B. Second direction

Claims

1. It includes a metal case, packaging components, and multiple electrode sets. The package member includes two package portions arranged opposite each other and has an internal space, the two package portions are joined at a predetermined position to partition the internal space of the package member into a plurality of sealed housing cavities, and the electrode set is provided in at least one of the sealed housing cavities. The metal case is fitted onto the outside of the package member, and the metal case seals the space inside the metal case. A battery characterized in that the air pressure between the metal case and the package member is lower than the air pressure outside the metal case, and the air pressure inside the sealed housing cavity is lower than the air pressure between the metal case and the package member.

2. The battery according to claim 1, characterized in that the package member is formed by folding a integrally molded package film along a predetermined fold line, and the two package portions are composed of the portions of the package film on both sides of the fold line.

3. The battery according to claim 1, characterized in that the two package portions are two package films.

4. The battery according to any one of claims 1 to 3, wherein the cavity wall of the sealed housing cavity includes two side walls provided opposite to each other along the thickness direction of the battery, and at least one of the side walls of at least one of the sealed housing cavities recesses outward from the sealed housing cavity to form a groove, the groove housing the electrode set.

5. The battery according to any one of claims 1 to 4, characterized in that the two package portions are joined together by thermal melting at predetermined positions.

6. The battery according to any one of claims 1 to 5, characterized in that the battery includes a first direction, the plurality of electrode sets are arranged along the first direction, and the electrode set includes a first electrode and a second electrode, respectively, located on both sides of the electrode set along the first direction.

7. The battery according to claim 6, 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 embedded in the junction position corresponding to the two package portions.

8. The battery according to claim 1, characterized in that the atmospheric pressure P1 between the metal case and the package member is -100 kPa to -5 kPa.

9. The battery according to claim 8, characterized in that the air pressure in the sealed housing cavity is P2, the relationship between P1 and P2 satisfies P1 > P2, and the range of P1 / P2 is 0.05 to 0.

85.

10. The battery according to claim 9, characterized in that the value of P2 is between -100 kPa and -20 kPa.

11. The battery according to any one of claims 1 to 10, characterized in that the battery includes a first direction, the plurality of electrode sets are arranged along the first direction, the length of the electrode sets extends along the first direction, the length of the battery extends along the first direction, and the length of the battery is 400 mm to 2500 mm.

12. The battery according to claim 11, characterized in that the thickness of the battery extends along a second direction, the metal case has two first surfaces facing each other along the second direction, and at least one of the first surfaces is recessed into the interior of the metal case.

13. The battery according to claim 12, characterized in that both of the first surfaces are recessed inside the metal case and sandwich the electrode set.

14. The battery according to any one of claims 11 to 13, characterized in that the battery is substantially rectangular and the thickness of the battery is greater than 10 mm.

15. The battery according to claim 14, characterized in that the ratio of the length to the thickness of the battery is 5 to 250.

16. The battery according to any one of claims 1 to 15, characterized in that the metal case is provided with air vents and a sealing member is provided within the air vents.

17. The battery according to any one of claims 1 to 16, characterized in that the wall thickness of the metal case is 0.05 mm to 1 mm.

18. A battery module characterized by including a battery according to any one of claims 1 to 17.

19. It includes a battery array comprising multiple batteries, each of which comprises a metal case, a packaging member, and multiple electrode sets. The package member includes two opposing package portions, the two package portions are joined at a predetermined position, and the internal space of the package member is divided into a plurality of sealed housing cavities, and an electrode set is provided in at least one of the sealed housing cavities. The metal case is fitted onto the outside of the package member, and the metal case seals the space inside the metal case. A battery pack characterized in that the air pressure between the metal case and the package member is lower than the air pressure outside the metal case, and the air pressure inside the sealed housing cavity is lower than the air pressure between the metal case and the package member.

20. The thickness of the battery extends along the second direction, and the plurality of the batteries are arranged sequentially in the second direction to form the battery row. The battery pack according to claim 19, 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.

21. 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 to seal the internal space of the case body. The battery pack according to claim 20, characterized in that the gap includes a first gap d1, the first gap d1 being the minimum distance along the second direction between the two cover plates of the two adjacent batteries, the thickness of the battery 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 battery being 0.005 to 0.

1.

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 to seal the internal space of the case body, The battery pack according to claim 20 or 21, characterized in that the battery has two first surfaces facing each other along a second direction, the gap includes a second gap d2, the second gap d2 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.

23. The battery pack according to claim 22, characterized in that the first gap d1 before use of the battery is larger than the second gap d2 after use.

24. An electric vehicle characterized by including a battery pack according to any one of claims 19 to 23.

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