Patent Application
20240021919
Embodiments of this application relate to the technical field of batteries, and in particular, to a battery and an electric apparatus.
At present, a battery typically includes a plurality of battery cells and end plates, where the end plates are fixed to two ends of the plurality of battery cells in their arrangement direction, and are used to resist expansion forces of the plurality of battery cells during charging and discharging. Therefore, the end plates need to not only have high strength to resist an expansion force of the battery cells in their whole life cycle, but also keep insulated from the battery cells to prevent short circuit between the battery cells and the end plates.
To obtain high strength, end plates are often made of a metal material and composited with an insulating material to realize insulation between the end plates and the battery cells. An end plate with such structure can realize insulation between the end plate and the battery cells under normal operating conditions. However, after some battery cells in a battery experience thermal runaway, the insulation between the end plate and the battery cells is apt to fail, causing high voltage short circuit of the battery.
In view of the foregoing problem, embodiments of this application provide a battery and an electric apparatus, which can not only guarantee strength and insulation requirements on an end plate in normal use of the battery, but also reduce risks of high voltage short circuit in thermal runaway of the battery.
According to one aspect of the embodiments of this application, a battery is provided, including: a plurality of battery cells arranged in a first direction; an end plate disposed at an end of the plurality of battery cells in the first direction; an insulating member for connecting with the end plate, where the insulating member is arranged on the top surface of the end plate in a second direction, the second direction being perpendicular to the first direction; where the insulating member has a maximum length A in a third direction, and the end plate has a maximum length B in the third direction, where A≥0.9B and the third direction is perpendicular to the first direction and the second direction.
By using the foregoing solution, the end plate is disposed at the end of the plurality of battery cells for resisting an expansion force of the plurality of battery cells during charging and discharging, and the insulating member has a large length in the third direction, almost enough to fully cover the top surface of the end plate. Therefore, the insulating member can not only provide considerably complete insulation protection for the end plate when the battery is in normal use, but also fully cover the top surface of the end plate in a case of melting of the insulating member caused by thermal runaway of the battery cells. In this way, creepage distances and electrical gaps at all portions on the top of the end plate can still meet an insulation requirement and therefore avoid high-voltage ignition between the end plate and the battery cells.
In some embodiments, 0.9B≤A≤B.
By using the foregoing solution, an unnecessary volume of the insulating member is saved while the insulation protection of the insulating member to the end plate is guaranteed, facilitating a small volume of the battery.
In some embodiments, the battery cells have a maximum length C in the third direction, where A≥0.9C.
In some embodiments, projections of the insulating member and the battery cells in the first direction at least partially overlap.
By using the foregoing solution, an edge of the top surface of the battery cells in the second direction is separated from the top surface of the end plate by the insulating member. Therefore, when an electrical signal of the battery cells is led out from the top of the end plate, the electrical signal is protected from the end plate by the insulating member, which increases the creepage distance and electrical gap between the battery cells and the end plate, thus preventing a short circuit between the battery cells and the end plate.
In some embodiments, the insulating member has a minimum thickness greater than or equal to 1.5 mm in the second direction.
By using the foregoing solution, an insulation failure between the battery cells and the end plate caused by a small thickness of the insulating member is avoided.
In some embodiments, a melting point of the insulating member is greater than 100° C.
By using the foregoing solution, it is possible to prevent melting of the insulating member and loss or weakening of the insulation effect when the battery cells experience thermal runaway.
In some embodiments, the end plate is provided with a mounting hole running through in the second direction, where the mounting hole is configured to allow a fastener to pass through for fastening the battery.
The insulating member is provided with a barrier, where the barrier is used to separate the battery cells from an end portion of the fastener extending out of the mounting hole.
By using the foregoing solution, the fastener is generally made of metal, and the barrier can prevent short circuit between the battery cells and the fastener.
In some embodiments, the battery further includes a plurality of bus members for implementing electrical connection of the plurality of battery cells, where the insulating member is provided with a mounting base, and at least one of the bus members is fixedly connected to the mounting base.
In some embodiments, the mounting base is provided with a first connecting hole, where at least one of the bus members is provided with a second connecting hole corresponding to the first connecting hole in position, and the second connecting hole and the first connecting hole are configured to allow a connector to pass through to implement fixed connection between the at least one of the bus members and the mounting base.
By using the foregoing solution, after the bus members electrically connect the plurality of battery cells, electrical signals of the plurality of battery cells are led out from at least one of the bus members, and efforts are made to prevent the bus members and the end plate from direct contact which causes short circuit. The bus members are fixedly connected to the mounting base to prevent the bus members from shaking during operation of an electric apparatus which affects stability of the electrical connection between the plurality of battery cells and stable output of the electrical signals.
In some embodiments, the battery further includes a signal monitoring member for monitoring voltage and/or temperature signals of the plurality of battery cells, where a signal input terminal of the signal monitoring member is electrically connected to the plurality of battery cells, and a signal output terminal of the signal monitoring member is fixed to the insulating member.
By using the foregoing solution, the signal output terminal of the signal monitoring member is fixed to the insulating member to prevent the signal monitoring member and the end plate from direct contact which causes short circuit.
In some embodiments, the insulating member is provided with a mounting groove, and the signal output terminal of the signal monitoring member is fixed to the mounting groove.
By using the foregoing solution, the signal monitoring member is fixed to the mounting groove in the insulating member, so that a user can directly connect to the signal output terminal in the mounting groove to receive a signal output by the signal monitoring member, which is convenient for the user.
In some embodiments, an insulating layer is provided between the bottom surface of the insulating member and the top surface of the end plate.
By using the foregoing solution, the insulation layer strengthens insulation protection on the end plate and further increases the creepage distance and electrical gap between the battery cells and the end plate to prevent short circuit between the battery cells and the end plate.
According to another aspect of the embodiments of this application, an electric apparatus is provided, including the battery of any one of the foregoing embodiments, the battery being used to provide electrical energy.
In the embodiments of this application, the insulating member is disposed above the end plate and length of the insulating member is increased, so that the insulating member fully covers the end plate, thereby reducing a probability of short circuit between the battery cells and the end plate.
The foregoing description is merely a summary of the technical solutions of the embodiments of this application. To make the technical means of the embodiments of this application understood more clearly so as to enable implementation in accordance with the content of the specification, and to make the foregoing and other objectives, features, and advantages of the embodiments of this application more obvious and easier to understand, specific embodiments of this application are described below.
To describe the technical solutions in the embodiments of this application more clearly, the following briefly describes the accompanying drawings for describing the embodiments. Apparently, the accompanying drawings in the following description show some embodiments of this application, and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.
In order to make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following clearly and completely describes the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some rather than all of the embodiments of the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the protection scope of this application.
Unless otherwise defined, all technical and scientific terms used in this specification have same meanings as those generally understood by a person skilled in the art of this application. The terms used in this specification of this application are only intended to describe the specific embodiments and are not intended to limit this application.
The terms “include” and “have” and any variations thereof in the specification, claims, and the accompanying drawing of this application are intended to cover non-exclusive content. The terms “one” or “a/an” does not exclude the presence of plurality.
The “embodiment” mentioned in this specification means that a specific feature, structure or characteristic described in combination with the embodiments may be included in at least one embodiment of this application. The term “embodiment” appearing in different parts of the specification does not necessarily refer to the same embodiment or an independent or alternative embodiment exclusive of other embodiments. It may be explicitly or implicitly appreciated by a person skilled in the art that the embodiments described in this specification may be combined with other embodiments.
The term “and/or” in this specification merely describes associations between associated objects, and it indicates the possible presence of three relationships. For example, A and/or B may indicate that the presence of only A, both A and B, or only B. In addition, the character “/” in this specification generally indicates that the associated objects are in an “or” relationship.
Orientation words in the following description are all directions shown in the drawings and are not intended to limit specific structures of a battery and an electric apparatus of this application. For example, in the description of this application, the terms such as “central”, “longitudinal”, “transverse”, “long”, “wide”, “thick”, “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer”, “clockwise”, “anticlockwise”, “axial”, “radial” and “circumferential” are used to indicate orientations shown in the drawings. It should be noted that these terms are merely intended to facilitate a simple description of this application, rather than to indicate or imply that the mentioned apparatus or elements must have the specific orientation or must be constructed and operated in the specific orientation. Therefore, these terms should not be construed as limitations on this application.
In addition, the expressions such as X direction, Y direction, and Z direction are not absolute but relative, where the expressions are used to indicate directions in which components of the battery and the electric apparatus in the embodiments are constructed and operated. In addition, although these indications are appropriate when the components of a battery pack are in the positions shown in the drawings, when these positions have changed, these directions should be interpreted differently to correspond to the changes.
In addition, the terms “first”, “second”, and the like in the specification, claims, or accompanying drawings of this application are used to distinguish between different objects, rather than describe a particular order, and may explicitly or implicitly include one or more of the features.
In the description of this application, unless otherwise specified, “plurality” means more than two (two inclusive), and similarly, “a plurality of groups” means more than two groups (two groups inclusive).
In the description of this application, it should be noted that unless otherwise specified and limited, the terms “mount”, “connect” and “join” should be understood in their broad senses. For example, the “joining” or “connection” of mechanical structures may refer to a physical connection, which is, for example, a fixed connection, for example, a fixed connection via a screw, a bolt, or other fasteners. Physical connection may alternatively be a detachable connection, for example, mutual clamping or buckling. Physical connection may alternatively be an integral connection, for example, welding, bonding, or integrally-formed connection. The “joining” or “connection” of circuit structures may refer to a physical connection or an electrical connection or signal connection. For example, it may refer to a direct connection, which is a physical connection, or an indirect connection via at least one intermediate element provided that circuit connectivity is achieved, or an internal communication between two elements. Signal connection may be implemented through a circuit or a medium, for example, a radio wave. A person of ordinary skill in the art should understand specific meanings of the foregoing terms in this application based on specific situations.
In this application, a battery cell may be a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, or the like. This is not limited by the embodiments of this application. The battery cell may be cylindrical, flat, cuboid, or the like. This is not limited in the embodiments of this application, either. Battery cells are generally classified into three types according to a packaging manner: cylindrical battery cells, prismatic battery cells, and pouch battery cells. This is not limited in the embodiments of this application, either.
The battery cell includes a shell, an electrode assembly, and an electrolyte, where the electrode assembly consists of a positive electrode plate, a negative electrode plate, and a separator. The battery cell works mainly depending on migration of metal ions between the positive electrode plate and the negative electrode plate. The positive electrode plate includes a positive electrode current collector and a positive electrode active material layer, where the positive electrode active material layer is applied on a surface of the positive electrode current collector. The part of positive electrode current collector not coated with the positive electrode active material layer protrudes from the part of positive electrode current collector coated with the positive electrode active material layer, and the part of positive electrode current collector not coated with the positive electrode active material layer is used as a positive tab. A lithium-ion battery is used as an example. A material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer, where the negative electrode active material layer is applied on a surface of the negative electrode current collector. The part of negative electrode current collector not coated with the negative electrode active material layer protrudes from the part of negative electrode current collector coated with the negative electrode active material layer, and the part of negative electrode current collector not coated with the negative electrode active material layer is used as a negative tab. A material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. To ensure that a high current can pass without causing fusing, there may be a plurality of positive tabs which are stacked together, and there may be a plurality of negative tabs which are stacked together. A material of the separator may be PP, PE, or the like. In addition, the electrode assembly may be a winding structure or a laminated structure, which is not limited in the embodiments of this application.
The shell includes a housing and an end cover assembly, where the housing is provided with an accommodating cavity and an opening. In other words, the housing does not have a side wall in one direction so that the accommodating cavity communicates with the outside of the housing. After the electrode assembly is loaded into the accommodating cavity through the opening, the opening is closed by the end cover assembly, electrolyte is injected into the accommodating cavity through an injection hole in the end cover assembly, and finally the injection hole is sealed to prevent gaseous, liquid, or solid substances from circulating between the inside and outside of the housing.
The battery typically includes a combination of a plurality of battery cells that are arranged in one direction, and end plates are disposed at two ends of the battery cells in their arrangement direction. The end plates confine the battery cells to a given area to resist an expansion force of the battery cells, and further, the end plates need to keep insulated from the battery cells to prevent short circuit between the battery cells and the end plates.
Therefore, if the end plates are made of a non-metal material, the end plates do not have enough strength to resist the expansion force of the battery cells in their whole life cycle; if the end plates are made of a metal material, short circuit is apt to occur between the end plates and the battery cells, and even high-voltage ignition may occur, which affects use performance and safety performance of the battery.
In view of this, in a relevant technology, end plates are composited with an insulating material to achieve insulation between the end plates and the battery cells. An end plate with such structure reduces risks of short circuit between the battery cells and the end plate to some extent while meeting the strength requirement. However, in use of the battery, short circuit may sometimes occur between the battery cells and the end plates and cause high-voltage ignition.
The inventors have found after research that the foregoing problem is because the use of insufficient insulating material on the end plate as in the prior art results in a small coverage of the insulating material on the end plate, which makes the end plate prone to insulation failure. Especially when one of the battery cells in the battery experiences thermal runaway, high-temperature emissions produced by the battery cell will soften and melt the insulating material, so that a creepage distance and electrical gap between the battery cells and the end plate become smaller, causing short circuit and even high-voltage ignition between the battery cells and the end plate.
In view of this, an embodiment of this application provides a battery with an insulating member provided on an end plate and an increased coverage area of the insulating member on the end plate, enabling the end plate of the battery to not only guarantee strength and insulation requirements in normal use of the battery, but also reduce risks of high voltage short circuit in thermal runaway of the battery.
The battery in this embodiment of this application may be applied to a variety of electric apparatuses that use a battery, for example without limitation, cell phones, portable devices, laptop computers, electric scooters, electric toys, electric tools, electric automobiles, ships, and spacecrafts. For example, spacecrafts include but are not limited to aircrafts, rockets, shuttles, and spaceships.
As shown in
For example, the battery 200 includes two end plates 201, two side plates 202, the end plates 201 and the side plates 202 enclosing a cavity structure for accommodating the battery cells 400.
In an embodiment, the end plates 201 and the side plates 202 may all be made of metal materials, such as aluminum or aluminum alloy, the end plates 201 and the side plates 202 are welded to each other, and the battery cells 400 are disposed inside the cavity enclosed by the end plates 201 and the side plates 202.
It can be understood that the battery cells 400 may be placed separately in the cavity enclosed by the end plates 201 and the side plates 202, or a plurality of battery cells 400 may be combined into a battery module and one or more such battery modules are placed in the cavity enclosed by the end plates 201 and the side plates 202.
As shown in
Shape of the housing 20 depends on shape of the one or more electrode assemblies 40 combined. For example, the housing 20 may be a hollow cuboid, a hollow cube, or a hollow cylinder. When the housing 20 is a hollow cuboid or cube, one of the planes of the housing 20 is an open plane where no housing wall is present so that the housing 20 communicates with the outside. When the housing 20 is a hollow cylinder, at least one round side of the housing 20 is an open plane, where no housing wall is present on that round side so that the housing 20 communicates with the outside. The housing 20 may be made of metal material or plastic, and in some embodiments, the housing 20 is made of aluminum or aluminum alloy.
As shown in
The electrode assembly 40 has a positive tab 41 and a negative tab 42. The connection members 30 are used to electrically connect the electrode assembly 40 to the electrode terminals 12. For example, in some embodiments, one connection member 30 is used to electrically connect the positive tab 41 to the positive electrode terminal and the other connection member 30 is used to electrically connect the negative tab 42 to the negative electrode terminal.
The end cover assembly 1 is also provided with an injection hole 13 for injecting electrolyte into the accommodating cavity. The injection hole 13 is sealed after the electrolyte injection is completed.
The plurality of battery cells 400 are arranged in a first direction. For example, in an embodiment, the plurality of battery cells 400 are bound and fastened together by a tie after being arranged in the first direction, the first direction being a Y direction shown in
The end plate 201 is disposed at an end of the plurality of battery cells 400 in the first direction. In an embodiment, two end plates 201 are disposed respectively on outer sides of battery cells 400 disposed at endmost parts in the first direction, where the outer side is a side, away from the remaining battery cells 400, of the battery cell 400 disposed at an end. A material of the end plate 201 may be a metal material, for example, aluminum or aluminum alloy, so as to resist an expansion force of the plurality of battery cells 400 during charging and discharging.
The insulating member 203 is disposed on the top surface of the end plate 201 in a second direction, and the insulating member 203 is connected to the end plate 201. In one embodiment, a material of the insulating member 203 may be a non-metal material such as polycarbonate-ABS resin composite (PC-ABS), polypropylene (PP), or fusible polytetrafluoroethylene (FPA). It is defined that the insulating member 203 has a maximum length A in a third direction and the end plate 201 has a maximum length B in the third direction, where A≥0.9B. The second direction is perpendicular to the first direction and the third direction is perpendicular to the first direction and the second direction. For example, the second direction is a Z direction shown in
In the foregoing solution of this embodiment, the insulating member 203 has a large length in the third direction, almost enough to fully cover the top surface of the end plate 201. Therefore, the insulating member 203 can not only provide considerably complete insulation protection for the end plate 201 when the battery 200 is in normal use, but also fully cover the top surface of the end plate 201 in a case of melting of the insulating member 203 caused by thermal runaway of the battery cells 400. In this way, creepage distances and electrical gaps at all portions on the top of the end plate 201 can still meet an insulation requirement and therefore avoid high-voltage ignition between the end plate 201 and the battery cells 400.
In some embodiments, to ensure insulation protection performance of the insulating member 203 for the end plate 201 and save an unnecessary volume of the insulating member 203, the maximum length of the insulating member 203 in the third direction is less than or equal to the maximum length of the end plate 201 in the third direction, that is, 0.9B≤A≤B. Such arrangement can prevent the insulating member 203 from occupying a large space, thereby facilitating a small volume of the battery 200.
In some embodiments, the battery cell 400 has a maximum length C in the third direction, where A≥0.9C. Because the length of the insulating member 203 in the third direction is close to the length of the battery cells 400 in the third direction, the insulating member 203 can further prevent short circuit between the end plate 201 and the battery cells 400.
In some embodiments, projections of the insulating member 203 and the battery cells 400 in the first direction at least partially overlap. In this embodiment, an edge of the top surface of the battery cells 400 in the second direction is well fitted to the insulating member 203, so that the insulating member 203 separates the edge of the battery cells 400 from the top surface of the end plate 201. Therefore, when an electrical signal of the battery cells 400 is led out from the top of the end plate 201, where the electrical signal is led out is protected from the end plate 201 by the insulating member 203, thus increasing the creepage distance and electrical gap between the battery cells 400 and the end plate 201, and further preventing short circuit between the battery cells 400 and the end plate 201.
In use of the battery 200, when the battery cells 400 are short-circuited, overcharged, pinched, shocked, or experience other like issues, the battery cells 400 may experience thermal runaway during which the battery cells 400 produce a large quantity of emissions that have a high temperature. Therefore, in some embodiments, a melting point of the insulating member 203 is greater than 100° C., which can prevent melting of the insulating member 203 and loss or weakening of the insulation effect when the battery cells 400 experience thermal runaway.
As shown in
Referring to
In one embodiment, the mounting base 2032 is provided with a nut 2033, and the first connecting hole 5 is a hole in the nut 2033.
By using the foregoing solution, after the bus members 204 electrically connect the plurality of battery cells 400, electrical signals of the plurality of battery cells 400 are led out from at least one of the bus members 204, and efforts are made to prevent the bus members 204 and the end plate 201 from direct contact which causes short circuit. The bus members 204 are fixedly connected to the mounting base 2032 to prevent the bus members 204 from shaking during operation of an electric apparatus which affects stability of the electrical connection between the plurality of battery cells 400 and the stable transmission of the electrical signals.
In some embodiments, the battery 200 further includes a signal monitoring member 205, where the signal monitoring member 205 is used to monitor voltage and/or temperature signals of the plurality of battery cells 400, a signal input terminal of the signal monitoring member 205 is electrically connected to the plurality of battery cells 400, and a signal output terminal of the signal monitoring member 205 is fixed to the insulating member 203. It can be understood that the signal monitoring member 205 is a printed circuit board (PCB) or a flexible circuit board (FPC). Optionally, the insulating member 203 is provided with a mounting groove 2034, and the signal output terminal of the signal monitoring member 205 is fixed to the mounting groove 2034. For example, the signal output terminal of the signal monitoring member 205 is connected to the mounting groove 2034 by using a screw. This solution can prevent the signal monitoring member 205 from directly contacting the end plate 201 to cause short circuit. Further, a user can directly connect to the signal output terminal in the mounting groove 2034 to collect a signal output by the signal monitoring member 205, which is convenient for the user.
As shown in
The insulating member 203 is provided with a barrier 2031, where the barrier 2031 is used to separate the battery cells 400 from an end portion of the fastener extending out of the mounting hole 2011. The barrier 2031 being disposed can prevent short circuit between the battery cells 400 and the fastener.
In an embodiment of this application, to enhance an insulation protection effect of the insulating member 203, a minimum thickness of the insulating member 203 in the second direction is greater than or equal to 1.5 mm to prevent insulation failure between the battery cells 400 and the end plate 201 caused by a small thickness of the insulating member 203.
In the foregoing embodiment, the insulating layer 206 provides enhanced insulation protection for the end plate 201 to further increase the creepage distance and electrical gap between the battery cells 400 and the end plate 201, thereby preventing short circuit between the battery cells 400 and the end plate 201.
In summary, for the battery 200 described above, the insulating member 203 is disposed above the end plate 201 and length of the insulating member 203 is increased, so that the insulating member 203 fully covers the end plate 201, thereby reducing a probability of short circuit between the battery cells 400 and the end plate 201.
Because the battery 200 in this application has the above-mentioned features, an electric apparatus that uses the battery 200 provided in this application to provide electrical energy also has the same features that can prevent the battery 200 from short-circuiting.
A person skilled in the art can understand that, combinations of features of different embodiments of this application fall within the scope of this application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.
The foregoing embodiments are merely used to explain the technical solutions of this application, but are not intended to limit the same. Although this application is described in detail with reference to the foregoing embodiments, persons of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent replacements on some technical features therein. These modifications or replacements do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the embodiments of this application.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202120733682.2 | Apr 2021 | CN | national |
This application is a continuation of International Patent Application No. PCT/CN2022/076681 filed on Feb. 17, 2022 which claims priority from Chinese Patent application 202120733682.2 filed on Apr. 9, 2021. The above-referenced applications are incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2022/076681 | Feb 2022 | US |
| Child | 18343235 | US |
