The present disclosure claims priority to Chinese Patent Application No. 201911162027.X, entitled “BATTERY, BATTERY MODULE, BATTERY PACK, AND ELECTRIC VEHICLE” and filed by BYD Co., Ltd. on Nov. 22, 2019.
The present disclosure relates to the field of batteries, and specifically, to a battery, a battery module, a battery pack, and an electric vehicle.
With the continuous popularization of new energy vehicles, the usage requirements for power batteries in the new energy vehicles are increasingly high. Especially, to meet the requirements of users for an increased mile range of the new energy vehicles, the overall capacity of batteries of the new energy vehicles needs to be continuously increased. Generally, when a high voltage (high capacity) is required, a large number of electrode cores are connected in series to form an electrode core assembly, and then multiple electrode core assemblies are assembled into a power battery. However, power connection between two adjacent electrode cores needs to be achieved through an external power connector, which may result in more overall installation structures of the power battery, which increases the costs, and the overall weight. Moreover, the installation structures occupy a larger part of an internal space of the power battery, which reduces the overall space utilization of the power battery. More electrode cores arranged side by side indicate a more wasted space. In addition, when the multiple electrode core assemblies are used for forming the power battery, information of the electrode core assemblies in aspects of current, voltage, and temperature generally needs to be obtained in time, to better manage the power battery. However, the electrode core assemblies are inside the power battery, and after a housing of the power battery is sealed, signals such as the voltage, current, temperature of the electrode core assemblies inside the power battery cannot be acquired in real time. Therefore, how to acquire the signals of the multiple electrode core assemblies inside the battery is also a difficult problem that needs to be resolved in manufacture of the power battery.
This application provides a battery, including: a housing; a plurality of accommodating cavities arranged in the housing; a partition plate for separating two adjacent accommodating cavities; electrode core assemblies, arranged in the accommodating cavities, the electrode core assemblies being arranged in a first direction and connected in series; and a plurality of sampling wires, electrically connected to the electrode core assemblies correspondingly.
This application further provides a battery module, including the foregoing battery.
This application further provides a battery pack, including the foregoing battery or the foregoing battery module.
This application further provides an electric vehicle, including the foregoing battery module or the foregoing battery pack.
In embodiments of this application, the multiple electrode core assemblies are connected in series in the housing of the battery, which can increase the capacity of the battery, improve the connection stability between the electrode core assemblies, and reduce a manufacturing process and costs. In addition, all sampling wires are fixed through the wire harness channel in order in this application, thereby improving the sampling accuracy of the entire battery and safety of sampling wire harnesses.
To describe the technical solutions in the embodiments of this application more clearly, the following briefly introduces the accompanying drawings required in the embodiments. Apparently, the accompanying drawings in the following description show only some embodiments of this application, and a person of ordinary skill in the art may still derive other accompanying drawings from these accompanying drawings without creative efforts.
To make a person skilled in the art better understand solutions of this application, 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 this application. Apparently, the described embodiments are merely a part rather than all of the embodiments of this 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.
In the specification, claims, and accompanying drawings of this application, the terms “first”, “second”, or the like are to distinguish between different objects but do not indicate a particular order. In addition, the terms “include”, “have”, and any variant thereof are to cover a non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units; and instead, further optionally includes a step or unit that is not listed, or further optionally includes another step or unit that is intrinsic to the process, method, product, or device.
In the description of this application, it should be understood that orientation or position relationships indicated by the terms such as “center”, “longitudinal”, “transverse”, “length”, “width”, “thickness”, “on”, “below”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “axial direction”, “radial direction”, and “circumferential direction” are based on orientation or position relationships shown in the accompanying drawings, and are used only for ease and brevity of illustration and description for this application, rather than indicating or implying that the disclosed apparatus or component must have a particular orientation or must be constructed and operated in a particular orientation. Therefore, such terms should not be construed as limiting of this application.
The following describes technical solutions in embodiments of this application with reference to accompanying drawings.
Referring to
According to the battery 100 provided by this application, the multiple electrode core assemblies 30 are connected in series in the housing 10 of the battery 100, which can increase the capacity of the battery 100, improve the connection stability between the electrode core assemblies 30, and reduce a manufacturing process and costs. All sampling wires are fixed through the wire harness channel in order in this application, thereby improving the sampling accuracy of the entire battery and safety of sampling wire harnesses.
The first direction may be a length direction of the battery 100, for example, the first direction is an X direction shown in
In this application, the involved electrode core is an electrode core commonly used in the field of power batteries 100, and the electrode core and the electrode core assembly 30 are components inside the housing 10 of the battery 100, which are not to be understood as the battery 100 itself. The electrode core may be an electrode core formed by winding, or an electrode core made in a laminated manner. Generally, the electrode core at least includes an anode plate, a separator, a cathode plate, and an electrolyte solution. The electrode core is generally a component that is not completely sealed. In this application, an electrode core assembly 30 may be formed by a single electrode core, or may include at least two electrode cores. The at least two electrode cores are connected in parallel to form the electrode core assembly 30. For example, after two electrode cores are connected in parallel, the electrode core assembly 30 is formed; or after four electrode cores are connected in parallel, the electrode core assembly 30 is formed. Therefore, the battery 100 involved in this application cannot be simply understood as a battery module or a battery pack because the battery includes multiple electrode cores.
Generally, the number of electrode core assemblies 30 connected in series in the battery 100 may be determined according to an output voltage of each electrode core assembly 30, a width of a battery pack, and an overall voltage requirement for the battery pack. For example, a voltage systematically outputted by a battery 100 required by a vehicle is 300 V, and a voltage of a conventional iron-lithium battery 100 is 3.2 V. In the related art, the requirement can be met in a case that 100 batteries 100 are connected in series in a battery pack. However, in this application, assuming that two electrode core assemblies 30 are connected in series inside one battery 100, only 50 batteries 100 need to be arranged. By analogy, if ten electrode core assemblies 30 are connected in series, only ten batteries 100 need to be connected in series. That is, by using the battery 100 in this application, the number of batteries 100 in the entire battery pack can be reduced, thereby effectively utilizing a space of the battery pack, and improving the space utilization of the battery pack.
The series connection between the electrode core assemblies 30 may be that the multiple electrode core assemblies 30 are sequentially connected in series, or the electrode core assemblies 30 are connected in series at intervals. For example, when there are four electrode core assemblies 30, the first electrode core assembly 30 and the third electrode core assembly 30 may be connected in series to form a first series of electrode core assemblies 30, the second electrode core assembly 30 and the fourth electrode core assembly 30 may be connected in series to form a second series of electrode core assemblies 30, and then the first series of electrode core assemblies 30 and the second series of electrode core assemblies 30 are connected in series.
When the multiple electrode core assemblies 30 are connected in series, there may be an internal short circuit problem in a case that electrolyte solutions in different electrode core assemblies 30 are in communication. In addition, there is a higher potential difference between different electrode core assemblies 30 (by using a lithium iron phosphate battery 100 as an example, a potential difference is approximately 4.0 to 7.6 V), and electrolyte solutions arranged in these electrode core assemblies may be decomposed due to the higher potential difference, which affects the performance of the battery 100. In this application, the partition plate 20 is arranged between adjacent electrode core assemblies 30. Preferably, to better achieve the insulation and separation, the partition plate 20 itself may be selected to be made of an insulating material, that is, the partition plate 20 is an insulating partition plate 20. In this way, without other operations, the two adjacent electrode core assemblies 30 may be directly separated by the partition plate 20 and the insulation between the two may be maintained.
In this application, the partition plates 20 divide an accommodating space into several accommodating cavities 60, and each of the accommodating cavities 60 accommodates the electrode core assembly 30, that is, two adjacent accommodating cavities 60 share one partition plate 20.
In this application, each accommodating cavity 60 may accommodate one electrode core assembly 30, or may accommodate multiple electrode core assemblies 30, for example, two or three. In some implementations, each accommodating cavity 60 accommodates one electrode core assembly 30.
In this application, the battery 100 further includes end covers 70 formed at two ends of the battery 100 in the first direction. The housing 10 may be an integral structure extending in the first direction, or may include multiple sub-housings 11 arranged in the first direction.
For example, in an embodiment of this application, as shown in
It should be noted that, the side circumferences of the partition plates 20 refer to circumferential surfaces of the partition plates 20 toward the housing 10, and coupling between the side circumferences of the partition plates 20 and the side walls of the housing 10 is not specifically limited, for example, a coupling manner of interference fit or adhesion.
In another embodiment of this application, as shown in
In this application, if the housing 10 is made of a corrosive material, for example, an aluminum housing, when the electrode core assemblies 30 are connected in series, lithium ions are embedded inside the housing 10 due to different voltages between different electrode core assemblies 30, to form a lithium aluminum alloy, which corrodes the aluminum housing. In this application, a separator film 80 may be arranged between the housing 10 and the electrode core assemblies 30, and is used for separating contact between electrolyte solutions and the housing 10.
For example, in another embodiment of this application, as shown in
The multiple sub-separator films 81 are multiple independent parts separated from each other, that is, the separator film 80 is a split-type separator film body. Each of the sub-separator films 81 is of a tubular structure with openings on two ends, and the electrode core assembly 30 is arranged inside the tubular sub-separator film 81. The partition plate 20 or the end cover 70 and an opening of the corresponding separator film 80 are connected and sealed, to form the accommodating cavity.
In this application, the sealed connection manner between the separator film 80 and the partition plate 20 or the end cover 70 and a specific structure thereof are not specifically limited. For example, when the partition plate 20 or the end cover 70 is made of a plastic material and the separator film 80 is made of plastic, sealed connection of hot melt may be used between the separator film 80 and the partition plate 20 or the end cover 70
In an embodiment of this application, as shown in
Coupling between the side circumferences of the partition plates 20 and the side walls of the separator film 80 is not specifically limited, for example, when the partition plates 20 and the separator film 80 are made of plastic, the separator film 80 may be connected and sealed to the partition plates 20 in a hot melt manner.
In an embodiment of this application, as shown in
The material of the separator film 80 is not specially limited, as long as the material has certain insulation and electrolyte solution corrosion resistance, and can provide insulation and does not react with an electrolyte solution. In some embodiments, the material of the separator film 80 may include polypropylene (PP), polyethylene (PE), or a multi-layer composite film. In some embodiments, the multi-layer composite film may include, for example, an inner layer, an outer layer, and an intermediate layer arranged between the inner layer and the outer layer. The inner layer may include a plastic material, for example, may be made of an insulative material less reactive to an electrolyte solution in the separator film 80. For example, the inner layer may include a PP or PE material. The intermediate layer may include a metal material, which can prevent vapor outside from entering the battery 100 and prevent the electrolyte solution inside from leaking out of the battery. An aluminum foil, a stainless steel foil, a copper foil, or the like are preferably selected as the metal material, and considering the molding performance, weight, and costs, the aluminum foil is preferable. For an aluminum foil material, priority is given to pure aluminum or aluminum-iron-based alloy materials. The outer layer is a protective layer, and may be made of a high melting point polyester or nylon material, to provide the strong mechanical performance and prevent an external force from damaging the battery 100, so as to protect the battery 100. When an inner film is a multi-layer composite film, one implementation is that, the inner film is an aluminum-plastic composite film.
In some embodiments, the separator film 80 has certain flexibility, which facilitates a molding process of the battery 100 and prevents the battery from being punctured. A thickness of the separator film 80 is preferably 80 μm to 200 μm, and may be certainly adjusted according to actual situations.
The electrolyte solution is a core component forming the battery 100, and the electrolyte solution needs to be filled into the accommodating cavity 60 in the battery 100 of this application. Therefore, an electrolyte solution channel is further arranged in the battery 100 of this application, the electrolyte solution channel is in communication with the accommodating cavity 60, and the electrolyte solution may be filled in the accommodating cavity 60 through the electrolyte solution channel. The electrolyte solution channels may be arranged on components such as the partition plate 20, the housing 10, the end cover 70, and the separator film 80.
For example, in an embodiment, as shown in
In an implementation, as shown in
In some embodiments, as shown in
A through hole may also be arranged at a position at which the housing 10 corresponds to the electrolyte solution filling channel 91 on the partition plate 20, and the through hole is used for communicating the electrolyte solution filling channel 91 and the exterior of the battery 100. When the structure of the battery 100 corresponds to that of the embodiments in
In an embodiment, when the battery 100 further includes a separator film 80, the electrolyte solution filling channel 91 may also be arranged on the separator film 80. Referring to the above description, the electrolyte solution filling channel 91 is used for filling an electrolyte solution from the exterior of the battery 100 into the accommodating cavity 60, and the electrolyte solution filling channels 91 are in communication with the corresponding accommodating cavities 60. The electrolyte solution filling channel 91 is in a closed state after electrolyte solution filling is completed, to separate the communication between the accommodating cavity 60 and the exterior of the battery 100. In this application, when the separator film 80 is made of plastic, hot melt is used for sealing, which can meet a sealing requirement for an electrolyte solution filling hole, and is more convenient to seal. For example, in some implementations, the separator film 80 includes a body of the separator film 80 and a protrusion protruding outward from the body of the separator film 80. In this case, an opening may be arranged on the protrusion, as the electrolyte solution filling channel 91. After electrolyte solution filling is completed, the protrusion with the opening may be sealed and tightened by hot melt.
That is, when the battery 100 further includes the separator film 80, the separator film 80 and the partition plate 20 form the accommodating cavity 60. Therefore, whether the electrolyte solution filling channel 91 is arranged on the partition plate 20 or the separator film 80, electrolyte solution may be filled into the battery 100, and then the housing 10 is mounted. In this way, the housing 10 has a secondary sealing effect on the electrolyte solution filling channel 91, and the sealing performance of the entire battery 100 is significantly improved. Once electrolyte solution leakage occurs in one of the accommodating cavities 60, the housing 10 provides a protection effect, to avoid a safety problem resulted from the electrolyte solution leakage. In addition, if a hole is arranged on the housing 10 for electrolyte solution filling, sealing and ensuring the strength of the housing 10 are both difficult problems. In this embodiment, without arranging the hole on the housing 10, the sealing of the electrolyte solution filling channel 91 is easier, and overall strength of the battery 100 is not considered too much.
In an embodiment, as shown in
As shown in
In some embodiments, as shown in
The electrolyte solution channel further includes an electrolyte solution filling hole, and the electrolyte solution filling hole may be arranged on the end cover 70. In this way, electrolyte solution is only filled from electrolyte solution filling holes on the end covers 70 on the end portions of the battery 100, and the electrolyte solution is guided from the electrolyte solution guide holes 93 on the partition plates 20 into the accommodating cavities 60. By arranging the electrolyte solution filling holes, the electrolyte solution can be filled into the accommodating cavities 60 once, and there is no need to open for multiple times to perform electrolyte solution filling for multiple times. Certainly, the electrolyte solution filling holes may also be arranged on the housing 10, the partition plates 20, or the separator film 80, and the electrolyte solution filling principle thereof is similar to that of the electrolyte solution filling holes arranged on the end covers 70.
In this application, referring to
In this application, as shown in
In some embodiments, referring to
In an embodiment of this application, a connection and a position relationship between the electrode core connector 40 and the partition plate 20 are shown in
In another embodiment of this application, a connection and a position relationship between the electrode core connector 40 and the partition plate 20 are shown in
Safety and stability are important for the power battery 100. For a conventional battery module and a battery pack, independent lithium-ion batteries connected in series/parallel are used to form the battery module or the battery pack, so that each lithium-ion battery may be sampled outside the each lithium-ion battery. However, if multiple electrode core assemblies 30 are connected in series and electrode lead-out members thereof are received in the housing 10 of the battery 100, it is not convenient to sample outside the battery 100 in the conventional manner. In this application, the sampling wires 50 may be arranged to be electrically connected to the electrode core connectors 40 and are leaded out from the partition plates 20 through the wire harness channel 54, thereby sampling each electrode core assembly 30 in the housing 10, to monitor a state of each electrode core assembly 30 to ensure safety and stability of the battery 100. The sampling wires 50 arranged in this application can resolve a sampling problem of the electrode core assemblies 30 connected in series inside the battery 100.
In some embodiments, as shown in
In some embodiments, as shown in
In some other embodiments, as shown in
In some embodiments, a sampling hole is arranged on the battery 100, the sampling wire 50 is leaded out from the wire harness channel 54 to the sampling hole, and the sampling hole is used for leading out a sampling signal. The sampling hole 51 may be arranged on the housing 10, as shown in
The wire harness channel may be a groove recessed in an internal surface of the housing 10, may be a pipe arranged on the internal surface or an external surface of the housing 10, or may be a pipe arranged at another position in the battery 100. All sampling wires are fixed through the wire harness channel in order in this application, thereby improving the sampling accuracy of the entire battery and safety of sampling wire harnesses.
For example, in an embodiment, with reference to
In other embodiments, the sampling wires 50 are connected to a circuit board, a connector, and the like after being leaded out from the wire harness channel 54.
In an embodiment, as shown in
In an embodiment, the wire harness channel 54 may include multiple sub wire grooves arranged at intervals, and the multiple sampling wires 50 after being leaded out from the partition plates 20 are respectively received in and fixed to the corresponding sub wire grooves, so that the multiple sampling wires 50 are arranged at intervals. In this way, short circuit by contact between adjacent sampling wires 50 can be prevented, and wear between the sampling wires 50 can be prevented.
In other embodiments, a connector may be further arranged on the battery 100, the sampling wires 50 are converged to the connector after being leaded out from the partition plates 20, and the connector may match a connector for external sampling, to lead out a sampling signal. The connector may be arranged on the housing 10, or may be arranged on the end cover 70. The connector may be a multi-probe type connector, a USB type connector, or another connector as required. For example, the connector includes a ceramic sleeve and multiple contact pins received in the ceramic sleeve, and each of the contact pins is electrically connected to one of the sampling wires correspondingly.
In an embodiment, the multiple sampling wires 50 may be further converged to a circuit board after being leaded out from the partition plates 20, a detection chip may be integrated on the circuit board, and the circuit board is used for generating a sampling signal according to information acquired by the sampling wires 50. The circuit board may be arranged on the side circumference of the housing 10 or the side circumference of the partition plate 20, or the circuit board may be arranged on the end cover 70. The circuit board may be further electrically connected to the connector, and the connector may be used for outputting the sampling signal generated by the circuit board. The detection chip may be integrated with components such as an odor sensor and a temperature sensor. Certainly, the components such as the odor sensor and the temperature sensor may also be directly attached to the circuit board and be electrically connected to the detection chip, to transmit detection data to the detection chip for processing.
The sampling wires 50 may also be connected to the circuit board and the connector after being leaded out from the wire harness channel 54.
For example, in an embodiment, as shown in
In an embodiment, as shown in
In some embodiments, the sampling wire 50 after being leaded out from the partition plate 20 may be a wire coated with an insulating layer, and may also prevent short circuit by contact between adjacent sampling wires 50. The sampling wire 50 may be a bare metal wire when being in the partition plate 20. The sampling wire 50 after being leaded out from the partition plate 20 may be electrically connected to the bare-metal-wire-type sampling wire 50 in the partition plate 20.
In an implementation of the present disclosure, the battery 100 further includes a detection unit, and the detection unit is directly sealed inside the housing 10 of the battery 100, which can facilitate the detection of the state of the electrode core assembly 30 in the housing 10 of the battery 100 at any time, and ensure the accuracy and timeliness of sampling information.
In the present disclosure, the battery 100 may be in various shapes, which may be a regular geometric shape or an irregular geometric shape, for example, may be a square, a circle, a polygon, a triangle, or may be in any shape for example, be a specially shaped battery 100. It may be understood that a shape of the battery 100 is not limited in the present disclosure. In an implementation, the battery 100 is substantially a cuboid, and the battery 100 has a length L, a width H, and a thickness D. The length L of the battery 100 is greater than the width H, and the width H of the battery 100 is greater than the thickness D. The length of the battery 100 is 400 mm to 2500 mm.
It should be noted that, the battery 100 being substantially a cuboid may be understood as that the battery 100 may be a cuboid, a cube, or substantially a cuboid or cube having a special shape locally; or may present an approximate cuboid or cube as a whole, but partially have a gap, a bulge, a chamfer, an arc, and a curve.
The thickness of the battery 100 of the present disclosure can be expanded in a wide range, and the battery 100 greater than 10 mm or more can be freely compatible, which is different from a conventional pouch battery 100 (less than 15 mm). An internal cavity is achieved in the conventional pouch battery 100 by stretching and molding of an aluminum-plastic composite film, and therefore the thickness of the interior of the battery 100 is limited by tensile performance of the aluminum-plastic composite film, and production of a great-thickness battery 100 cannot be implemented. The battery 100 in the technology can implement production of an over-10 mm-thickness battery 100.
In the present disclosure, the length L and the width H of the battery 100 meet: L/H=4 to 21.
In the present disclosure, the housing 10 is used for improving strength of the battery 100 and ensuring safe use of the battery 100, and the housing may be a plastic housing 10 or a metal housing 10. When the housing is a metal housing 10, the heat dissipation performance is better, and the housing 10 has a higher strength and can play a supporting role by itself.
In the present disclosure, the battery 100 may be a lithium-ion battery 100.
In the present disclosure, other structures, for example, an explosion-proof valve and a current interruption device, of the battery 100 are the same as conventional arrangements in the related art, which are not repeated herein.
As shown in
As shown in
An electric vehicle 1000 shown in
In the descriptions of the present disclosure, it should be noted that, unless otherwise explicitly specified or defined, the terms such as “install”, “connect”, and “connection” should be understood in a broad sense. For example, the connection may be a fixed connection, a detachable connection, or an integral connection; or the connection may be a mechanical connection or an electrical connection; or the connection may be a direct connection, an indirect connection through an intermediary, or internal communication between two components. A person of ordinary skill in the art may understand the specific meanings of the foregoing terms in the present disclosure according to specific situations.
In description of this specification, description of reference terms such as “an embodiment”, “specific embodiments”, or “an example”, means including specific features, structures, materials, or features described in the embodiment or example in at least one embodiment or example of the present disclosure. In this specification, schematic descriptions of the foregoing terms do not necessarily point at a same embodiment or example. In addition, the described specific features, structures, materials, or characteristics may be combined in a proper manner in any one or more of the embodiments or examples.
Finally, it should be noted that the foregoing implementations are merely for describing the technical solutions of the present disclosure but not for limiting the present disclosure. Although the present disclosure is described in detail with reference to the some implementations, a person of ordinary skill in the art should understand that they may still make modifications or equivalent replacements to the technical solutions described in the present disclosure without departing from the spirit and scope of the technical solutions of the embodiments of the present disclosure.
Number | Date | Country | Kind |
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201911162027.X | Nov 2019 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2020/130025 | 11/19/2020 | WO |