WO2023044764A1

WO2023044764A1 - Pressure balancing mechanism, battery, electric device, and method and device for preparing battery

Info

Publication number: WO2023044764A1
Application number: PCT/CN2021/120356
Authority: WO
Inventors: 陈彬彬
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2021-09-24
Filing date: 2021-09-24
Publication date: 2023-03-30
Also published as: CN116636071A

Abstract

Provided in the embodiments of the present application are a pressure balancing mechanism, a battery, an electric device, and a method and device for preparing a battery. The pressure balancing mechanism is for use in a battery to balance pressure inside and outside the battery, and comprises: a main body, which is internally provided with a channel having a first opening and a second opening at two ends, the first opening being configured to guide gas to the channel; a condensation sheet, which is configured to cover the second opening and is fixedly connected to the main body, the condensation sheet and the channel being configured to condense water vapor in the gas into condensate, and the condensation sheet being provided with a gas-permeable hole for the gas to pass therethrough; and a gas-permeable membrane, which is arranged on the side of the condensation sheet away from the second opening, is fixedly connected to the main body, and is configured to allow the passage of the gas and prevent the passage of the condensate. By means of the technical solution of the embodiments of the present application, the safety of a battery can be enhanced.

Description

Pressure balance mechanism, battery, electrical device, method and device for preparing battery

technical field

The present application relates to the technical field of batteries, in particular to a pressure balance mechanism, a battery, an electrical device, a method and a device for preparing a battery.

Background technique

With the increasing environmental pollution, the new energy industry has attracted more and more attention. In the new energy industry, battery technology is an important factor related to its development. In the development of battery technology, safety is an issue that cannot be ignored. If the safety of the battery cannot be guaranteed, the battery cannot be used.

Under normal circumstances, the pressure balance mechanism in the battery can meet the requirements of air permeability and is impervious to water, so as to maintain the internal and external pressure balance of the battery and prevent problems such as short circuit of the electrical connectors inside the battery. However, the current pressure balance mechanism can only be breathable and waterproof, but cannot prevent the water vapor in the air from passing through. When water vapor enters the battery through the pressure balance mechanism, condensate will be generated in the battery due to temperature changes, causing safety hazards , affecting the safety of the battery. Therefore, how to enhance the safety of batteries is a technical problem to be solved urgently in battery technology.

Contents of the invention

The present application provides a pressure balance mechanism, a battery, an electrical device, a method and a device for preparing the battery, which can enhance the safety of the battery.

In a first aspect, a pressure balancing mechanism is provided for a battery to balance the pressure inside and outside the battery, the pressure balancing mechanism includes: a main body, a channel is formed inside the main body, and first an opening and a second opening, the first opening is used to guide gas to the channel; a condensation sheet is used to cover the second opening and is fixedly connected with the main body, the condensation sheet and the channel are used for The water vapor in the gas is condensed into a condensate, and the condensing sheet is provided with vent holes, and the vent holes are used to allow the gas to pass through; a gas-permeable film is arranged on the condensing sheet away from the second opening One side of the body is fixedly connected with the main body, and the air-permeable membrane is used to allow the gas to pass through and prevent the condensate from passing through.

In the embodiment of the present application, a channel is formed in the main body of the pressure balance mechanism, so that the gas can be condensed in the channel, and at the same time, the condensation sheet at the end of the channel can accelerate the condensation of the gas, and minimize the entry into the battery after passing through the gas-permeable membrane In order to maintain the internal and external pressure balance of the battery, it reduces the impact of water vapor condensation on the interior of the battery and enhances the safety of the battery.

In a possible implementation manner, the pressure balance mechanism further includes: a piston member configured to be inserted into the channel through the first opening and fixedly connected to the main body.

By setting the piston member, the path of the gas in the channel can be further limited and extended, so that the gas can reach the condensation plate along the preset path after entering the channel, so as to realize the condensation of water vapor in the gas, further improve the condensation effect and reduce condensation The impact of the liquid on the inside of the battery enhances the safety of the battery.

In a possible implementation manner, a first gap is provided between the piston member and the passage to form a circulation path of the gas.

By forming a first gap between the piston member and the channel, the gas can pass through the first gap into the channel for condensation, reducing the impact of water vapor in the gas on the battery and enhancing the safety of the battery.

In a possible implementation manner, the inner surface of the channel and/or the outer surface of the piston member are provided with grooves to form the gas circulation path.

The groove between the piston member and the channel can form a gas flow path, so that the gas can enter the channel through the groove to condense, reduce the impact of water vapor in the gas on the battery, and enhance the safety of the battery.

In a possible implementation manner, the groove is in a spiral shape.

In the embodiment of the present application, the helical groove can further extend the flow path of the gas in the channel, thereby further condensing the water vapor in the gas, reducing the influence of the water vapor in the gas on the battery, and enhancing the safety of the battery.

In a possible implementation manner, the piston member includes a connected fixing part and an insertion part, the insertion part is used to be inserted into the channel, and the fixing part is used to be fixedly connected to the main body, wherein the A second gap is provided between the fixing portion and the first opening, so that the gas enters the channel through the second gap.

The piston component can be fixed through the connected fixing part and the insertion part, and the piston component with this structure has a simple structure and is easy to assemble.

In a possible implementation manner, a protrusion is provided on the edge of the fixing part, a notch is provided on the edge of the main body, and the protrusion cooperates with the notch to fix the piston member to the main body.

In the embodiment of the present application, the fixing method of the piston member can adopt the method of cooperation between the protrusion and the notch, which does not need to use additional parts for fixing, and has a simple structure and convenient operation.

In a possible implementation manner, the pressure balance mechanism further includes: a cover, configured to cover the first opening and connected to the main body, wherein a cover is provided between the cover and the first opening. There is a third gap such that the gas enters the channel through the third gap.

The pressure balance mechanism in the embodiment of the present application can separate the channel from the external environment through the cover, so that the temperature inside the channel is not easily affected by the temperature of the external environment, so that the gas entering the channel can be fully and effectively condensed, reducing The impact of water vapor in the gas on the battery enhances the safety of the battery.

In a possible implementation manner, a drain port communicating with the first opening is provided in the channel, and the drain port is used to drain the condensate out of the channel.

In the embodiment of the present application, after the gas is condensed in the channel, condensate will be generated. By setting the liquid outlet connected to the first opening, the generated condensate can be discharged to the outside of the channel in time, so as to avoid the accumulation of condensate on the channel. The effect is adversely affected.

In a possible implementation manner, the pressure balance mechanism further includes: a protection member, which is arranged on a side of the gas-permeable membrane away from the second opening and fixedly connected with the main body, the protection member is used for The gas-permeable membrane is protected, and the protection member has through holes for allowing the gas to pass through.

The gas-permeable membrane in the embodiment of the present application is arranged on the outermost side of the entire pressure balance mechanism, and without corresponding protection, it is easily damaged by the outside world. By arranging the protective element, the air-permeable membrane can be prevented from being damaged by the outside world. At the same time, the protective element is provided with through holes, so that the protective element can allow gas to pass through and enter the interior of the battery, thereby maintaining the balance of the internal and external pressure of the battery.

In a second aspect, there is provided a battery, the battery comprising: a plurality of battery cells and a case, the plurality of battery cells are accommodated in the case; and the pressure balance mechanism according to the first aspect, wherein , the pressure balance mechanism is arranged on the box body.

In a third aspect, there is provided an electric device, comprising: the battery according to the second aspect, the battery is used for providing electric energy.

In a possible implementation manner, the electrical device is a vehicle, ship or spacecraft.

In a fourth aspect, there is provided a method for preparing a battery, comprising: providing a plurality of battery cells and a case, the plurality of battery cells are accommodated in the case; providing a pressure balancing mechanism for the battery to To balance the pressure inside and outside the battery, the pressure balance mechanism is arranged on the box body, the pressure balance mechanism includes: a main body, a channel is formed inside the main body, and the two ends of the channel have a first opening and The second opening, the first opening is used to guide the gas to the channel; the condensation sheet is used to cover the second opening and is fixedly connected with the main body, the condensation sheet and the channel are used to guide the gas The water vapor in the gas is condensed into a condensate, and the condensing sheet is provided with vent holes, and the vent holes are used to allow the gas to pass through; side and is fixedly connected with the main body, and the air-permeable membrane is used to allow the gas to pass through and prevent the condensate from passing through.

In a fifth aspect, there is provided a device for preparing a battery, comprising: a first providing module, configured to provide a plurality of battery cells and a box, and the plurality of battery cells are accommodated in the box; a second providing module , used to provide a pressure balance mechanism for the battery to balance the pressure inside and outside the battery, the pressure balance mechanism is arranged on the box, the pressure balance mechanism includes: a main body, the inside of the main body is formed There is a channel with a first opening at both ends of the channel and a second opening, the first opening is used to guide gas to the channel; a condensation sheet is used to cover the second opening and is fixed to the body connected, the condensing sheet and the channel are used to condense the water vapor in the gas into a condensate, the condensing sheet is provided with air holes, and the air holes are used to allow the gas to pass through; the air-permeable film is provided On the side of the condensing sheet away from the second opening and fixedly connected to the main body, the air-permeable membrane is used to allow the gas to pass through and prevent the condensed liquid from passing through.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings that need to be used in the embodiments of the present application. Obviously, the accompanying drawings described below are only some embodiments of the present application. Those of ordinary skill in the art can also obtain other drawings based on the accompanying drawings on the premise of not paying creative efforts.

Fig. 1 is a schematic structural view of a vehicle disclosed in an embodiment of the present application;

Fig. 2 is a schematic structural diagram of a battery disclosed in an embodiment of the present application;

Fig. 3 is a schematic structural view of a battery cell group disclosed in an embodiment of the present application;

Fig. 4 is an exploded view of a battery cell disclosed in an embodiment of the present application;

Fig. 5 is an exploded view of a battery cell disclosed in another embodiment of the present application;

Fig. 6a is an exploded view of a pressure balance mechanism disclosed in an embodiment of the present application;

Figures 6b to 6c are structural schematic diagrams of the pressure balance mechanism at different angles corresponding to Figure 6a;

Fig. 7 is an exploded view of a pressure balance mechanism disclosed in another embodiment of the present application;

Fig. 8a is a schematic structural diagram of a body disclosed in an embodiment of the present application;

Figure 8b is a schematic cross-sectional view corresponding to Figure 8a;

Fig. 9 is a schematic cross-sectional view corresponding to the pressure balance mechanism in Fig. 7 to Fig. 8b;

Fig. 10 is a schematic structural diagram of a body disclosed in another embodiment of the present application;

Fig. 11 is a schematic structural diagram of a body disclosed in another embodiment of the present application;

Fig. 12 is an exploded view of a pressure balance mechanism disclosed in another embodiment of the present application;

Fig. 13 is a schematic structural view of a pressure balance mechanism disclosed in another embodiment of the present application;

Fig. 14a is a schematic structural view of a battery case disclosed in an embodiment of the present application;

Figure 14b is a partial detail view corresponding to position C in Figure 14a;

Fig. 15 is a schematic flow chart of a method for preparing a battery disclosed in an embodiment of the present application;

Fig. 16 is a schematic block diagram of a device for preparing a battery disclosed in an embodiment of the present application.

In the drawings, the drawings are not drawn to scale.

Detailed ways

The implementation manner of the present application will be further described in detail below with reference to the drawings and embodiments. The detailed description and drawings of the following embodiments are used to illustrate the principles of the application, but not to limit the scope of the application, that is, the application is not limited to the described embodiments.

In the description of this application, it should be noted that, unless otherwise specified, the meaning of "plurality" is more than two; the terms "upper", "lower", "left", "right", "inner", " The orientation or positional relationship indicated by "outside" and so on are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a reference to this application. Application Restrictions. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable range of error. "Parallel" is not strictly parallel, but within the allowable range of error.

The orientation words appearing in the following description are the directions shown in the figure, and do not limit the specific structure of the application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be interpreted in a broad sense, for example, it can be a fixed connection or a flexible connection. Disassembled connection, or integral connection; it can be directly connected or indirectly connected through an intermediary. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

In this application, a battery cell may include a primary battery or a secondary battery, such as a lithium-ion battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery, which is not limited in this embodiment of the application. . The battery cell can be in the form of a cylinder, a flat body, a cuboid, or other shapes, which are not limited in this embodiment of the present application. Battery cells are generally divided into three types according to packaging methods: cylindrical battery cells, square battery cells and pouch battery cells, which are not limited in this embodiment of the present application.

The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the batteries mentioned in this application may include battery cell groups or battery packs. A battery pack generally includes a case for enclosing one or more battery cells. The box can prevent liquid or other foreign objects from affecting the charging or discharging of the battery cells.

The battery cell includes an electrode assembly and an electrolyte, and the electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell works primarily by moving metal ions between the positive and negative plates. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The current collector without the positive electrode active material layer protrudes from the current collector coated with the positive electrode active material layer. The current collector coated with the positive electrode active material layer serves as the positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The current collector coated with the negative electrode active material layer serves as the negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon. In order to ensure that a large current is passed without fusing, the number of positive pole tabs is multiple and stacked together, and the number of negative pole tabs is multiple and stacked together. The material of the isolation film can be polypropylene (PP) or polyethylene (PE). In addition, the electrode assembly may be a wound structure or a laminated structure, which is not limited in the embodiment of the present application. The development of battery technology should consider many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, the safety of the battery also needs to be considered.

For batteries, the main safety hazard comes from the charging and discharging process. In order to improve the safety performance of the battery, the battery is generally equipped with a pressure balancing mechanism. The pressure balance mechanism can maintain the balance of the internal and external pressure of the battery.

In the current design, the pressure balance mechanism can include a gas-permeable membrane. When there is a pressure difference between the internal and external environments of the battery, the gas-permeable membrane can allow gas to pass through to ensure the pressure balance of the internal and external environments of the battery. Under normal circumstances, the gas-permeable membrane in the pressure balance mechanism is gas-permeable and allows gas to pass through. At the same time, the gas-permeable membrane can also prevent liquid water from passing through, so that liquid water can be prevented from entering the battery while maintaining the internal and external pressure balance of the battery. There is a problem such as a short circuit in the electrical connectors inside the battery. However, the gas-permeable film in the pressure balance mechanism cannot prevent the water vapor in the gas from entering the battery. When the temperature around the battery changes, the water vapor entering the battery will condense into condensate, or liquid water. The connectors cause potential safety hazards and affect the safety of the battery.

To solve this problem, in the current design, an air dryer is generally installed in the pressure balance mechanism, and the water vapor entering the battery is absorbed by the desiccant in the air dryer. However, the desiccant has a limited ability to absorb water vapor and needs to be replaced regularly, and the pressure balance mechanism using the desiccant generally has a complicated structure and high cost.

In view of this, the embodiment of the present application provides a technical solution, by forming a channel in the main body of the pressure balance mechanism, so that the gas can be condensed in the channel, and at the same time, the condensation sheet at the end of the channel can accelerate the condensation of the gas, Minimize the water vapor entering the battery after passing through the breathable membrane, so as to maintain the pressure balance inside and outside the battery while reducing the impact of water vapor condensation on the inside of the battery, such as electrical connectors, to enhance the safety of the battery.

The technical solutions described in the embodiments of the present application are applicable to various devices using batteries, such as mobile phones, portable devices, notebook computers, battery cars, electric toys, electric tools, electric vehicles, ships and spacecraft, etc. For example, spacecraft include Airplanes, rockets, space shuttles and spaceships, etc.

It should be understood that the technical solutions described in the embodiments of the present application are not limited to the devices described above, but can also be applied to all devices that use batteries. However, for the sake of brevity, the following embodiments take electric vehicles as examples for illustration.

For example, as shown in Figure 1, it is a schematic structural diagram of a vehicle 1 according to an embodiment of the present application. The vehicle 1 can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or Extended range cars, etc. A motor 40 , a controller 30 and a battery 10 can be arranged inside the vehicle 1 , and the controller 30 is used to control the battery 10 to supply power to the motor 40 . For example, the battery 10 may be provided at the bottom or front or rear of the vehicle 1 . The battery 10 can be used for power supply of the vehicle 1 , for example, the battery 10 can be used as an operating power source of the vehicle 1 , for a circuit system of the vehicle 1 , for example, for starting, navigating and running power requirements of the vehicle 1 . In another embodiment of the present application, the battery 10 can not only be used as an operating power source for the vehicle 1 , but can also be used as a driving power source for the vehicle 1 , replacing or partially replacing fuel oil or natural gas to provide driving power for the vehicle 1 .

In order to meet different power usage requirements, the battery of the present application may include multiple battery cells, wherein the multiple battery cells may be connected in series, in parallel or in parallel, and the hybrid connection refers to a mixture of series and parallel connections. Batteries can also be called battery packs. Optionally, a plurality of battery cells can be connected in series, parallel or mixed to form a battery module, and then a plurality of battery modules can be connected in series, parallel or mixed to form a battery. That is to say, multiple battery cells can directly form a battery, or form a battery module first, and then form a battery from the battery module.

For example, as shown in FIG. 2 , which is a schematic structural diagram of a battery 10 according to an embodiment of the present application, the battery 10 may include a plurality of battery cells 20 . The battery 10 may also include a box body, the inside of which is a hollow structure, and a plurality of battery cells 20 are accommodated in the box body. As shown in FIG. 2 , the box body may include two parts, referred to here as a first box body part 111 and a box body second part 112 , and the box body first part 111 and the box body second part 112 are fastened together. The shapes of the first box part 111 and the second box part 112 can be determined according to the combined shape of the battery cells 20 , and both the first box part 111 and the second box part 112 can have an opening. For example, the first part 111 of the box and the second part 112 of the box can be hollow cuboids and only one face is an opening face, the opening of the first part 111 of the box is opposite to the opening of the second part 112 of the box, and the box The first part 111 and the second part 112 of the box are interlocked to form a box with a closed chamber. A plurality of battery cells 20 are combined in parallel, in series or in parallel and placed in the box formed by fastening the first part 111 of the box body and the second part 112 of the box body.

Optionally, the battery 10 may also include other structures, which will not be repeated here. For example, the battery 10 may also include a confluence part, which is used to realize electrical connection between a plurality of battery cells 20 , such as parallel connection, series connection or mixed connection. Specifically, the current-combining component can realize the electrical connection between the battery cells 20 by connecting the electrode terminals of the battery cells 20 . Further, the bus member may be fixed to the electrode terminal of the battery cell 20 by welding. The electric energy of the plurality of battery cells 20 can be further drawn out through the box through the conductive mechanism.

According to different power requirements, the number of battery cells can be set to any value. Multiple battery cells can be connected in series, parallel or in parallel to achieve greater capacity or power. Since the number of battery cells included in each battery 10 may be relatively large, the battery cells may be arranged in groups for ease of installation, and each group of battery cells constitutes a battery cell group 200 . The number of battery cells included in the battery cell group 200 is not limited, and can be set according to requirements. For example, FIG. 3 is an example of a battery cell group. A battery may include a plurality of battery cell groups, and these battery cell groups may be connected in series, in parallel or in parallel.

As shown in FIG. 4 , which is a schematic structural diagram of a battery cell 20 according to an embodiment of the present application, the battery cell 20 includes one or more electrode assemblies 22 , a casing 211 and a cover plate 212 . The housing 211 and the cover plate 212 form the housing 21 . The walls of the casing 211 and the cover plate 212 are both referred to as walls of the battery cell 20 . The housing 211 depends on the combined shape of one or more electrode assemblies 22. For example, the housing 211 can be a hollow cuboid or cube or cylinder, and one of the surfaces of the housing 211 has an opening so that one or more electrodes Assembly 22 may be placed within housing 211 . For example, when the housing 211 is a hollow cuboid or cube, one of the planes of the housing 211 is an open surface, that is, the plane does not have a wall so that the inside and outside of the housing 211 communicate. When the casing 211 can be a hollow cylinder, the end surface of the casing 211 is an open surface, that is, the end surface does not have a wall so that the inside and outside of the casing 211 communicate. The cover plate 212 covers the opening and is connected with the casing 211 to form a closed cavity for placing the electrode assembly 22 . The casing 211 is filled with electrolyte, such as electrolytic solution.

The battery cell 20 may further include two electrode terminals 214 , and the two electrode terminals 214 may be disposed on the cover plate 212 . The cover plate 212 is usually in the shape of a flat plate, and two electrode terminals 214 are fixed on the flat plate surface of the cover plate 212, and the two electrode terminals 214 are positive electrode terminals 214a and negative electrode terminals 214b respectively. Each electrode terminal 214 is correspondingly provided with a connection member 23 , which is located between the cover plate 212 and the electrode assembly 22 , and is used for electrically connecting the electrode assembly 22 and the electrode terminal 214 .

As shown in FIG. 4 , each electrode assembly 22 has a first tab 221a and a second tab 222a. The polarities of the first tab 221a and the second tab 222a are opposite. For example, when the first tab 221a is a positive tab, the second tab 222a is a negative tab. The first tab 221a of one or more electrode assemblies 22 is connected to an electrode terminal 214 through a connecting member 23, and the second tab 222a of one or more electrode assemblies 22 is connected to another electrode terminal 214 through another connecting member 23. connect. For example, the positive electrode terminal 214 a is connected to the positive electrode tab through one connection member 23 , and the negative electrode terminal 214 b is connected to the negative electrode tab through the other connection member 23 .

In the battery cell 20 , according to the actual usage requirements, the electrode assembly 22 can be arranged as a single one or in multiples. As shown in FIG. 4 , four electrode assemblies 22 are arranged in the battery cell 20 .

As shown in FIG. 5 , it is a schematic structural diagram of a battery cell 20 including a pressure relief mechanism 213 according to another embodiment of the present application.

The housing 211, cover plate 212, electrode assembly 22 and connecting member 23 in FIG. 5 are consistent with the housing 211, cover plate 212, electrode assembly 22 and connecting member 23 in FIG. .

In FIG. 5 , the pressure relief mechanism 213 is disposed on the bottom wall of the battery cell 20 , that is, the wall 21a in FIG. 5 , wherein the pressure relief mechanism 213 can be a part of the wall 21a, or can be a separate structure from the wall 21a. , fixed on the wall 21a by, for example, welding. When the pressure relief mechanism 213 is a part of the wall 21a, for example, the pressure relief mechanism 213 can be formed by setting a notch on the wall 21a, and the thickness of the wall 21a corresponding to the notch is smaller than that of the pressure relief mechanism 213 except for the notch. The thickness of other areas. The notch is the weakest position of the pressure relief mechanism 213 . When the gas generated by the battery cell 20 is too much so that the internal pressure of the housing 211 rises and reaches a threshold value or when the heat generated by the internal reaction of the battery cell 20 causes the internal temperature of the battery cell 20 to rise and reach a threshold value, the pressure relief mechanism 213 can A crack occurs at the notch, which leads to communication between the inside and outside of the shell 211 , and the gas pressure and temperature are released outward through the crack of the pressure relief mechanism 213 , thereby preventing the battery cell 20 from exploding.

In FIG. 5 , the pressure relief mechanism 213 is located on the bottom wall of the battery cell 20 as an example for description, but it should be understood that the pressure relief mechanism 213 in the embodiment of the present application may be located on the side wall of the housing 211, or It is located on the cover plate 212, or may also be located at the intersection of the two walls of the housing 211, which is not limited in this embodiment of the present application.

The pressure relief mechanism 213 may be various possible pressure relief structures, which are not limited in this embodiment of the present application. For example, the pressure relief mechanism 213 may be a temperature-sensitive pressure relief mechanism configured to melt when the internal temperature of the battery cell 20 provided with the pressure relief mechanism 213 reaches a threshold; and/or, the pressure relief mechanism 213 may be a pressure-sensitive pressure relief mechanism configured to rupture when the internal air pressure of the battery cell 20 provided with the pressure relief mechanism 213 reaches a threshold value.

Furthermore, in order to maintain the pressure balance inside and outside the battery, a pressure balance mechanism can be provided on the battery, so that the pressure balance between the inside and outside of the battery can be maintained. However, in the current design of the pressure balance mechanism, although the gas-permeable membrane in the pressure balance mechanism has a breathable and waterproof function, it cannot prevent the water vapor in the gas from affecting the battery. Based on this, Fig. 6a shows an exploded view of a pressure balance mechanism 12 in the embodiment of the present application, and Fig. 6b to Fig. 6c are schematic diagrams of the assembled pressure balance mechanism corresponding to Fig. 6a at different angles. The pressure balance mechanism 12 in the embodiment of the application can reduce the influence of the condensation of water vapor in the gas on the electrical connectors inside the battery, and enhance the safety of the battery.

As shown in FIGS. 6 a to 6 c , the pressure balance mechanism 12 may include a main body 121 , a condensation sheet 122 and a gas-permeable membrane 123 . The pressure balancing mechanism 12 can be used in a battery to balance the pressure inside and outside the battery.

Wherein, the interior of the main body 121 is formed with a channel 1211, the two ends of the channel 1211 have a first opening 1211a and a second opening 1211b, the first opening 1211a is used to guide the gas to the channel 1211; the condensation sheet 122 is used to cover the second opening 1211b And fixedly connected with the main body 121, the condensation sheet 122 and the channel 1211 are used to condense the water vapor in the gas into a condensate, the condensation sheet 122 is provided with vent holes, and the vent holes are used to allow the gas to pass through; the breathable film 12 is arranged on the condensation sheet The side of 122 away from the second opening 1211b is fixedly connected to the main body 121, and the air-permeable membrane 123 is used to allow gas to pass through and prevent condensate from passing through.

By forming a channel 1211 in the main body 121 of the pressure balance mechanism 12, the gas can be condensed in the channel 1211, and at the same time, the condensation sheet 122 at the end of the channel 1211 can accelerate the condensation of the water vapor in the gas, and reduce the air flow as much as possible. The water vapor entering the battery after the membrane 123 maintains the pressure balance inside and outside the battery while reducing the impact of water vapor condensation on the inside of the battery, such as electrical connectors, and enhancing the safety of the battery.

The pressure balance mechanism 12 in the embodiment of the present application can be arranged on the case of the battery, wherein the end of the main body 121 provided with the condensation sheet 122 can be located inside the battery, so that the gas can pass through the first The opening 1211a enters the channel 1211, and the gas can experience a certain temperature change in the channel 1211, so that part of the water vapor in the gas can condense on the inner surface of the channel 1211 to form condensate, or liquid water, and further, the gas passes through the channel 1211 After touching the condensing sheet 122, the condensation process of the water vapor in the gas is accelerated under the action of the condensing sheet 122, so that the water vapor in the gas is condensed into a condensate. At the same time, because the condensing sheet 122 is provided with vent holes, the air The part except water vapor or a small amount of water vapor can pass through the air holes on the condensation sheet 122 to reach the air-permeable film 123, and finally enter the interior of the battery through the air-permeable film 123. During this process, since the gas has condensed through the channel 1211 and the condensation sheet 122 before reaching the air-permeable membrane 123, the pressure balance mechanism 12 in the embodiment of the present application can greatly reduce the water vapor contained in the gas, reducing The impact of water vapor entering the battery on the battery enhances the safety of the battery.

The pressure balance mechanism 12 in the embodiment of the present application can also be called a balance valve, an explosion-proof valve, etc., and its main function is to maintain the pressure balance inside and outside the battery, and the embodiment of the present application does not limit its name.

Optionally, the ventilation holes provided on the condensation sheet 122 in the embodiment of the present application can be adopted in various ways, for example, the condensation sheet 122 can be set as a fine mesh structure as a whole, so that the area through which the gas can pass can be increased, Speed up the gas flow, so as to ensure a large balance of pressure inside and outside the battery, or, one or more through holes can also be set on the condensation sheet 122 to allow the gas to pass through the condensation sheet 122, the specific setting method can be determined according to the battery requirements, the embodiment of the present application There is no limit to this.

As an implementation manner, the condensation sheet 122 in the embodiment of the present application may be a material with a high thermal conductivity, such as a metal material. Generally speaking, the higher the thermal conductivity of the material, the better the heat conduction effect. The condensing sheet 122 in the embodiment of the present application adopts a material with high thermal conductivity, which is more conducive to the condensing sheet 122 taking away the high temperature of the gas, which is beneficial to the gas Condensation of water vapor in.

Optionally, the condensation sheet 122 in this embodiment of the present application may be made of stainless steel, such as 304 stainless steel.

In the above-mentioned embodiment, the gas is condensed only through the channel 1211 formed in the main body 121 and the condensation sheet 122. Although the gas can be condensed in the channel 1211, the condensation effect is limited. In order to further improve the pressure balance mechanism 12 in the embodiment of the present application The condensation effect can be achieved by further prolonging the gas flow path.

As an implementation manner, the pressure balance mechanism 12 may further include: a piston member 124 configured to be inserted into the channel 1211 through the first opening 1211 a and fixedly connected to the main body 121 .

FIG. 7 shows an exploded view of a pressure balance mechanism 12 with a piston member 124 in an embodiment of the present application. As shown in FIG. 7 , the piston member 124 can be inserted into the channel 1211 , and the surface of the part of the piston member 124 located in the channel 1211 can form a path allowing gas to pass between the inner surface of the channel 1211 . Specifically, a first gap is provided between the piston member 124 and the channel 1211 to form a circulation path of the gas.

By setting the piston member 124, the path of the gas entering the channel 1211 can be further limited and extended, so that the gas can reach the condensation plate 122 along the preset path after entering the channel 1211, so as to fully condense the water vapor in the gas, and further Improve the condensation effect, reduce the impact of condensate on the inside of the battery, and enhance the safety of the battery.

In order to form a flow path that allows gas between the piston member 124 and the channel 1211, as an implementation, the radial dimension of the part of the piston member 124 that is located in the channel 1211 can be set to be smaller than the radial dimension of the channel 1211, so that The above-mentioned first gap is formed between the piston member 124 and the channel 1211 so that gas can reach the condensation sheet 122 through the first gap.

Or, as another implementation manner, the inner surface of the channel 1211 and/or the outer surface of the piston member 124 is provided with a groove 125 to form a gas flow path. Optionally, the groove 125 is helical. The spiral groove 125 in the embodiment of the present application may also be called the spiral groove 125 .

Specifically, as an example, Fig. 8a shows a schematic structural view of a main body 121 provided with a spiral groove 125. Fig. 8b is a sectional view corresponding to Fig. 8a. As shown in Figures 8a and 8b, the spiral groove 125 is arranged on the inner surface of the channel 1211, and one end thereof extends to the end of the first opening 1211a, so as to allow gas to enter the spiral groove 125 through the first opening 1211a, and in addition One end extends to the second opening 1211b to allow the gas to pass through the spiral groove 125 and reach the condensation sheet 122 for condensation.

By providing the spiral groove 125 on the inner surface of the channel 1211 and/or the outer surface of the piston member 124 , a gas flow path can be formed between the channel 1211 and the piston member 124 . Optionally, when the inner surface of the channel 1211 and/or the outer surface of the piston member 124 is provided with the helical groove 125 , the radial dimension of the piston member 124 may be smaller than or equal to the radial dimension of the channel 1211 .

Optionally, the above-mentioned groove 125 may also be configured in other shapes, such as a linear groove running through the channel 1211 , which is not limited in this embodiment of the present application.

Further, in order to fix the piston member 124 on the main body 121 , as shown in FIG. 7 , the piston member 124 may include a fixing part 1241 and an insertion part 1242 . Specifically, the piston member 124 includes a connected fixing portion 1241 and an insertion portion 1242, the insertion portion 1242 is used to be inserted into the channel 1211, and the fixing portion 1241 is used to be fixedly connected to the main body 121, wherein, between the fixing portion 1241 and the first opening 1211a A second gap is provided so that gas enters the channel 1211 through the second gap.

In order to fix the fixing part 1241 to the main body 121, as an implementation, the edge of the fixing part 1241 is provided with a protrusion 1243, and the edge of the main body 121 is provided with a notch 1212, and the protrusion 1243 cooperates with the notch 1212 to secure the piston member 124 fixed on the main body 121.

Optionally, in the embodiment of the present application, a groove for accommodating the fixing part 1241 can be provided at the first opening 1211a of the main body 121, such as the groove area 1213 shown in FIG. 7 , the groove area 1213 can be circular, or It may also have other shapes, which are not limited in this embodiment of the present application. Correspondingly, the fixing part 1241 can also have a cylindrical structure, so as to cooperate with the groove area 1213 to realize the fixing of the fixing part 1241 on the main body 121 .

Further, in order to allow gas to enter the channel 1211 through the fixed part 1241, a gap allowing the passage of gas is provided between the fixed part 1241 and the groove area 1213. Optionally, the gap can be set in various ways, for example, the fixed part The radial dimension of 1241 can be smaller than the radial dimension of the groove area 1213, so that when the fixing portion 1241 is fixed on the main body 121, the aforementioned second gap can be formed between the fixing portion 1241 and the groove area 1213, the second The gap may allow gas to pass through.

Or optionally, a gap may be directly provided on the fixing part 1241 , so that the gas can directly enter the channel 1211 through the gap, which is not limited in this embodiment of the present application.

It should be understood that the above-mentioned fixing method of the pressure balance mechanism 12 through the protrusion 1243 and the notch 1212 can be used in combination with the fixing method of the groove area 1213 on the main body 121, or can also be realized separately, which is not limited in the embodiment of the present application .

Alternatively, the piston member 124 in the embodiment of the present application may also be fixed on the main body 121 in other ways, such as by bonding, riveting, welding, etc., which is not limited in the embodiment of the present application.

FIG. 9 shows a schematic cross-sectional view of a pressure compensation mechanism 12 with a piston component 124 corresponding to FIGS. 7 to 8b. As shown in FIG. 9 , the piston member 124 may have a fixing portion 1241 and an insertion portion 1242 , wherein the piston member 124 may cooperate with the notch 1212 through a protrusion 1243 to fix the piston member 124 . Further, the main body 121 can be provided with a groove area 1213 as described in the foregoing embodiments, so that the fixing part 1241 can cooperate with the groove area 1213 to achieve fixation. Wherein, the radial dimension of the fixing portion 1241 may be smaller than the radial dimension of the groove region 1213 , so that a gap may be formed between the fixing portion 1241 and the groove region 1213 , and gas may enter the channel 1211 through the gap. Subsequently, the gas can pass through the spiral groove 125 in the channel 1211 to reach the condensation sheet 122 for condensation. Wherein, the path through which the gas passes may refer to the direction of the arrow shown in FIG. 9 .

In the embodiment of the present application, the water vapor in the gas can be condensed into a condensate before passing through the gas-permeable membrane 123, thereby reducing the impact of the water vapor entering the battery on the battery. After condensation, the condensed liquid needs to be discharged out of the channel 1211 to prevent it from affecting the condensation effect of the channel 1211 . Specifically, a liquid discharge port 1214 communicating with the first opening 1211 a is disposed in the channel 1211 , and the liquid discharge port 1214 is used to drain the condensate out of the channel 1211 .

The above-mentioned drain port can be set in various ways, for example, the drain port 1214 shown in Fig. 7 to Fig. The liquid port 1214 can extend to communicate with the groove 125 in the aforementioned embodiment, so that the liquid water stored in the groove 125 can be discharged out of the channel 1211 through the liquid outlet 1214 .

Optionally, the length of the drain port 1214 may extend to the same length as the channel 1211, or may only extend from the first opening 1211a to a certain distance into the channel 1211. In addition, the location of the drain port 1214 may also be set according to It needs to be set actually, and this embodiment of the present application does not limit it.

The air-permeable membrane 123 in the embodiment of the present application is disposed on the outermost side of the entire pressure balance mechanism 12, and is easily damaged by the outside world without corresponding protection.

As an implementation, the pressure balance mechanism 12 also includes: a protective member 127, which is arranged on the side of the gas-permeable membrane 123 away from the second opening 1211b and fixedly connected with the main body 121. The protective member 127 is used to protect the gas-permeable membrane 123. The protective member 127 has a through hole for passing gas.

As shown in Figure 7, the protective piece 127 in the pressure balance mechanism 12, by setting the above-mentioned protective piece 127, the air-permeable membrane 123 can be prevented from being damaged by the outside world, and at the same time, the protective piece 127 is provided with a through hole 1271, so that the protective piece 127 can allow The gas passing through the gas permeable membrane 123 passes through and enters the inside of the battery, thereby maintaining the balance of the internal and external pressures of the battery 10 .

Optionally, the through hole 1271 provided on the protective piece 127 can be provided in various ways. As shown in FIG. A plurality of small through holes 1271 with a relatively small diameter, which is not limited in this embodiment of the present application.

Optionally, the condensation sheet 122 , the breathable membrane 123 , the protection piece 127 and the like in the embodiment of the present application can be fixed on the main body 121 in various ways, such as bonding, riveting, welding and the like. For example, when the main body 121, the gas-permeable membrane 123, and the protective member 127 are made of materials such as engineering plastics, the above-mentioned components and the main body 121 can be fixed by hot-melt welding. , the condensation sheet 122 can be fixed in the main body 121 by way of interference fit. In the embodiment of the present application, the manner in which each component is fixed on the main body 121 may be determined according to the material used for the component and requirements, which is not limited in the embodiment of the present application.

As an implementation, in order to improve the sealing between the pressure balance mechanism 12 and the battery, as shown in Figures 7 to 9, a sealing ring 13 can also be provided between the battery and the pressure balance mechanism 12, specifically, the The pressure balance mechanism 12 also includes: a sealing ring 13, which is arranged at the connection position between the main body 121 and the battery, so as to seal the battery.

The sealing ring 13 disposed on the main body 121 can closely fit the battery after the pressure balance mechanism 12 is fixed on the battery, thereby improving the sealing performance of the battery.

It should be understood that, except that the pressure balance mechanism 12 with the piston member 124 can be provided with the drain port 1214, the protection member 127 and the sealing ring 13, the above components can also be provided in other embodiments of the pressure balance mechanism 12 in the present application. The application embodiment does not limit this.

The above embodiment gives an example of a pressure balance mechanism 12 provided with a piston member 124. Through the piston member 124, the circulation path of the gas can be extended to a certain extent, the condensation of the gas can be realized, and the impact of water vapor in the gas on the battery can be reduced. impact, enhance the safety of the battery. Optionally, the pressure balance mechanism 12 in the embodiment of the present application may not use the piston member 124 , but realize the condensation of gas through other structures of the main body 121 .

As an implementation manner, FIG. 10 shows a schematic structural diagram of a main body 121 in an embodiment of the present application. As shown in Figure 10, the main body 121 in the embodiment of the present application can be a hollow structure, that is, the main body 121 has a hollow channel 1211 as shown in Figure 10, wherein the aforementioned condensation sheet can be provided at the second opening 1211b of the channel 122 and breathable membrane 123. Optionally, a protective member 127 may also be provided in this embodiment of the present application. At this time, the gas can enter the channel 1211 from the first opening 1211 a, and condense through the condensation sheet 122 provided at the second opening 1211 b, and then enter the interior of the battery through the gas-permeable membrane 123 .

The hollow channel 1211 in the above embodiment has a simple structure and has a limited condensation effect on gas. In order to further improve the condensation effect on gas, it can be realized by extending the channel 1211 .

As another implementation manner, FIG. 11 shows a schematic structural diagram of another main body 121 in the embodiment of the present application. As shown in FIG. 11 , the channel 1211 in the main body 121 can be a circuitous S-shaped channel, and the S-shaped channel can be opened in the solid main body 121. Similarly, the gas can enter the channel 1211 from the first opening 1211a, and pass through the S-shaped channel. The condensation sheet 122 provided at the second opening 1211b condenses, and then can enter the interior of the battery through the gas-permeable membrane 123 .

Compared with the hollow channel 1211 in Figure 10, the S-shaped channel 1211 in the embodiment of the present application can guide the gas to pass through the S-shaped path, further prolonging the length of the condensation path of the gas, thereby enhancing the condensation effect of the channel 1211 on the gas, reducing The content of water vapor entering the battery enhances the safety of the battery.

Alternatively, the channel 1211 in the embodiment of the present application may also adopt other methods, which is not limited in the embodiment of the present application.

In order to reduce the impact of the external environment on the pressure balance mechanism 12, as an implementation, the pressure balance mechanism 12 in the embodiment of the present application may further include a cover 126, which is used to cover the first opening 1211a and connect to the main body 121, Wherein, a third gap is provided between the cover member 126 and the first opening 1211a, so that the gas enters the channel 1211 through the third gap.

FIG. 12 shows an exploded view of a pressure balance mechanism 12 provided with a cover 126 in an embodiment of the present application.

By providing the cover 126 , the channel 1211 can be isolated from the external environment, so that the gas entering the channel 1211 can be better condensed.

Optionally, in order to fix the cover 126 on the main body 121, similar to the arrangement of the aforementioned piston member 124, in this embodiment of the present application, a plurality of protrusions 1261 may be provided on the edge of the cover 126, correspondingly, the first opening 1211a A plurality of notches 1212 are provided at the edge of the body, and the protrusions 1261 can cooperate with the notches 1212 to realize the fixing of the cover 126 on the main body 121 .

Further, a groove for accommodating the cover 126 may be provided at the first opening 1211a, such as the groove area 1213 shown in FIG. The area 1213 is also correspondingly circular, or the cover 126 and the groove area 1213 may also have other shapes, which are not limited in this embodiment of the present application.

Further, in order to allow gas to enter the channel 1211 through the cover 126, a third gap that allows the passage of gas may be provided between the cover 126 and the groove area 1213. Optionally, the third gap may be set in various ways For example, the radial dimension of the cover 126 can be smaller than the radial dimension of the groove area 1213, so that when the cover 126 is fixed on the main body 121, a third gap can be formed between the cover 126 and the groove area 1213 , to allow gas to pass through. Alternatively, a gap may also be directly provided on the cover 126 so that the gas can directly enter the channel 1211 through the gap, which is not limited in this embodiment of the present application.

Optionally, the cover 126 in the embodiment of the present application can also be set to directly cover the end of the first opening 1211a without cooperating with the groove area 1213 on the main body 121, which is not made in the embodiment of the present application. limit.

The main body 121 in the embodiment of the present application may have different external structures, for example, the main body 121 shown in Fig. 6a to Fig. 12 all has a cylindrical external structure.

Further, as shown in FIG. 13 , the main body 121 may also include two parts, one part is the head 1215 for fixing the cover 126 or the piston member 124, and the other part is the channel part 1216 for forming the channel 1211, that is, the main body 121 can have the same structure as a bolt, and the bolt usually has two parts: a head and a screw rod (a cylindrical part with an external thread), wherein the head 1215 of the main body can correspond to the head of the bolt, and the channel part 1216 of the main body 121 It can correspond to the screw part of the bolt, which means that the whole main body 121 can be regarded as a bolt structure.

At this time, the thread structure 1217 can be provided outside the passage portion 1216 of the main body 121, and the main body can be fixed on the battery box through the thread structure 1217, so that the installation is more convenient and quick. Alternatively, the main body 121 can also have other shapes, such as a cuboid structure. At this time, the main body 121 can be fixed on the battery box by bonding, riveting, welding, etc. limit. FIG. 13 shows a schematic structural diagram of another pressure balance mechanism 12 in the embodiment of the present application. As shown in FIG. 13 , the main body 121 can be fixed on the case of the battery through the installation hole 1215 a.

In order to better condense the gas entering the pressure balance mechanism 12, as an implementation manner, the pressure balance mechanism 12 in the embodiment of the present application may be arranged in a region of the battery provided with a cooling component.

FIG. 14a is a schematic structural diagram of a battery case 11 in the embodiment of the present application. Figure 14b is a detail view corresponding to position C in Figure 14a. As shown in Figures 14a and 14b, the battery case 11 is provided with a water inlet 113 of a water cooling system, and the water cooling system is used to input fluid to the heat management components inside the case 11. The fluid regulates the temperature of the battery cells. Generally speaking, the position where the water inlet 113 is provided and the surrounding area have a lower temperature, so that the pressure balance mechanism 12 arranged near the water inlet 113 is more likely to reach the temperature of condensation, thereby accelerating the flow into the channel 1211. Gas condensation reduces the impact of water vapor entering the battery on the battery and enhances battery safety.

It should be understood that the above embodiment takes the water inlet 113 disposed on the side wall of the box body 11 as an example. In practical applications, the water inlet 113 may also be located on the bottom wall of the box body 11, as long as the pressure balance in the embodiment of the present application is The mechanism 12 can be disposed in the surrounding area of the water inlet 113 , and the embodiment of the present application does not limit the specific locations of the water inlet 113 and the pressure balance mechanism 12 .

The embodiment of the present application provides a battery, the battery includes a plurality of battery cells 20 and a box body 11, and a plurality of battery cells 20 are accommodated in the box body 11; and the pressure balance mechanism 12 in the foregoing embodiments, wherein , The pressure balance mechanism 12 is arranged on the box body 11 .

An embodiment of the present application also provides an electric device, which may include the battery in the foregoing embodiments, and the electric device is used to provide electric energy.

Optionally, the electrical device may be a vehicle 1 , a ship or a spacecraft.

The above describes the pressure balance mechanism 12, the battery and the electrical device of the embodiment of the present application, and the method and device for preparing the battery of the embodiment of the present application will be described below, and the parts not described in detail can be referred to the foregoing embodiments.

FIG. 15 shows a schematic flowchart of a method 300 for preparing a battery according to an embodiment of the present application. As shown in Fig. 14, the method 300 may include the following steps.

S310, providing a plurality of battery cells 20 and a casing 11 .

As an implementation manner, a plurality of battery cells 20 are accommodated in the box body 11 .

S320, providing a pressure balance mechanism 12 .

As an implementation, the pressure balance mechanism 12 is used in the battery to balance the pressure inside and outside the battery. The pressure balance mechanism 12 is arranged on the box body 11. The pressure balance mechanism 12 includes: a main body 121, and a channel 1211 is formed inside the main body 121. Both ends of 1211 have a first opening 1211a and a second opening 1211b, the first opening 1211a is used to guide the gas to the channel 1211; the condensation sheet 122 is used to cover the second opening 1211b and is fixedly connected with the main body 121, the condensation sheet 122 and The channel 1211 is used to condense the water vapor in the gas into a condensate, and the condensing sheet 122 is provided with vent holes, and the vent holes are used to allow the gas to pass through; the ventilating film 123 is arranged on the side of the condensing sheet 122 away from the second opening 1211b And fixedly connected with the main body 121, the air-permeable membrane 123 is used to allow gas to pass through and prevent condensate from passing through.

FIG. 16 shows a schematic block diagram of a device 400 for preparing a battery cell according to an embodiment of the present application. As shown in FIG. 15 , the device 400 for preparing a battery may include: a first providing module 410 and a second providing module 420 .

The first providing module 410 is used for providing a plurality of battery cells 20 and the case body 11 , and the plurality of battery cells 20 are accommodated in the case body 11 .

The second providing module 420 is used to provide the pressure balance mechanism 12, the pressure balance mechanism 12 is arranged on the box body 11, the pressure balance mechanism 12 includes: a main body 121, a passage 1211 is formed inside the main body 121, and the two ends of the passage 1211 have a second An opening 1211a and a second opening 1211b, the first opening 1211a is used to guide the gas to the channel 1211; the condensation sheet 122 is used to cover the second opening 1211b and is fixedly connected with the main body 121, the condensation sheet 122 and the channel 1211 are used to guide the gas The water vapor in the condensate is condensed into a condensate, and the condensing sheet 122 is provided with air holes, which are used to allow gas to pass through; the air-permeable film 123 is arranged on the side of the condensing sheet 122 away from the second opening 1211b and is fixedly connected with the main body 121 , The air-permeable membrane 123 is used to allow gas to pass through and prevent condensate from passing through.

While the application has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the application. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

A pressure balancing mechanism used in a battery to balance the pressure inside and outside the battery, characterized in that the pressure balancing mechanism includes:

a main body, a channel is formed inside the main body, the two ends of the channel have a first opening and a second opening, and the first opening is used to guide gas to the channel;

a condensation sheet, used to cover the second opening and fixedly connected with the main body, the condensation sheet and the channel are used to condense the water vapor in the gas into a condensate, and the condensation sheet is provided with ventilation holes , the vent holes are used to allow the gas to pass through;

A gas-permeable film is arranged on a side of the condensation sheet away from the second opening and fixedly connected to the main body, the gas-permeable film is used to allow the gas to pass through and prevent the condensate from passing through.
The pressure balance mechanism according to claim 1, wherein the pressure balance mechanism further comprises:

The piston member is configured to be inserted into the channel through the first opening and fixedly connected with the main body.
The pressure balance mechanism according to claim 2, characterized in that a first gap is provided between the piston member and the channel to form a flow path for the gas.
The pressure balance mechanism according to claim 2 or 3, characterized in that grooves are provided on the inner surface of the channel and/or the outer surface of the piston member to form the flow path of the gas.
The pressure balance balancing mechanism according to claim 4, wherein the groove is helical.
The pressure balance mechanism according to any one of claims 2 to 5, characterized in that, the piston member includes a fixed part and an insertion part connected together, the insertion part is used to be inserted into the channel, and the fixed part Used for fixed connection with the main body, wherein a second gap is provided between the fixing part and the first opening, so that the gas enters the channel through the second gap.
The pressure balance mechanism according to claim 6, wherein a protrusion is provided on the edge of the fixing part, a notch is provided on the edge of the main body, and the protrusion cooperates with the notch to hold the The piston member is fixed to the main body.
The pressure balance mechanism according to claim 1, wherein the pressure balance mechanism further comprises:

a cover for covering the first opening and connected to the main body, wherein a third gap is provided between the cover and the first opening so that the gas enters through the third gap the channel.
The pressure balance mechanism according to any one of claims 1 to 8, wherein a drain port communicating with the first opening is provided in the channel, and the drain port is used to dissipate the condensed liquid exits the channel.
The pressure balance mechanism according to any one of claims 1 to 9, wherein the pressure balance mechanism further comprises:

A protective piece is arranged on a side of the air-permeable membrane away from the second opening and is fixedly connected to the main body, the protective piece is used to protect the air-permeable membrane, the protective piece has a through hole, and the through-hole The holes are used to pass the gas.
A battery, characterized in that it comprises:

a plurality of battery cells and a case in which the plurality of battery cells are accommodated; and

The pressure balance mechanism according to any one of claims 1 to 10, wherein the pressure balance mechanism is arranged on the box body.
An electric device, characterized by comprising: the battery according to claim 11, the battery is used to provide electric energy.
A method for preparing a battery, comprising:

providing a plurality of battery cells and a case, the plurality of battery cells being accommodated in the case;

A pressure balance mechanism is provided for the battery to balance the pressure inside and outside the battery, the pressure balance mechanism is arranged on the box, and the pressure balance mechanism includes:

a main body, a channel is formed inside the main body, the two ends of the channel have a first opening and a second opening, and the first opening is used to guide gas to the channel;

a condensation sheet, used to cover the second opening and fixedly connected with the main body, the condensation sheet and the channel are used to condense the water vapor in the gas into a condensate, and the condensation sheet is provided with ventilation holes , the vent holes are used to allow the gas to pass through;

A gas-permeable film is arranged on a side of the condensation sheet away from the second opening and fixedly connected to the main body, the gas-permeable film is used to allow the gas to pass through and prevent the condensate from passing through.
A device for preparing a battery, characterized in that it comprises:

a first providing module, configured to provide a plurality of battery cells and a box, and the plurality of battery cells are accommodated in the box;

The second providing module is used to provide a pressure balance mechanism for the battery to balance the pressure inside and outside the battery, the pressure balance mechanism is arranged on the box, and the pressure balance mechanism includes:

a main body, a channel is formed inside the main body, the two ends of the channel have a first opening and a second opening, and the first opening is used to guide gas to the channel;

a condensation sheet, used to cover the second opening and fixedly connected with the main body, the condensation sheet and the channel are used to condense the water vapor in the gas into a condensate, and the condensation sheet is provided with ventilation holes , the vent holes are used to allow the gas to pass through;

A breathable and breathable film is arranged on the side of the condensation sheet away from the second opening and fixedly connected with the main body, the breathable and breathable film is used to allow the gas to pass through and prevent the condensate from passing through.