Battery monomer and battery module

Abstract

The utility model discloses a battery monomer and a battery module. The battery monomer comprises a shell, a one-way gas-permeable membrane and an electrode assembly, a one-way breathable film is arranged on the shell; the electrode assembly is positioned in the shell and is connected with a polar terminal at the top of the shell; and the polar terminal is provided with a mounting part for mounting the heat exchange tube. According to the utility model, the single battery is provided with the one-way gas-permeable membrane, the one-way gas-permeable membrane can discharge gas generated in the single battery out of the single battery shell, and when the single battery is assembled into the battery module, the gas pressure in the gas area of each single battery can be basically kept consistent, so that the cycle life of the battery module is ensured; and the probability of thermal runaway of the battery module is reduced.

Description

Technical Field

[0001] The utility model belongs to the field of batteries, and specifically relates to a battery monomer and a battery module. Background Art

[0002] Common lithium-ion batteries are divided into button batteries, square batteries and cylindrical batteries according to their appearance.

[0003] The electrode components in the square battery are arranged in the order of positive electrode-diaphragm-negative electrode, assembled by lamination or winding process, and then encapsulated in a square aluminum shell.

[0004] With the continuous development of science and technology, the market demand for batteries with high safety and large capacity is getting stronger and stronger. Therefore, how to ensure the safety of batteries while increasing the battery capacity has become a technical hotspot in the battery field.

[0005] A battery module is provided in the related art, which includes a plurality of battery cells. After the battery module has been running for a period of time, the inconsistent gas pressure inside each battery cell will affect the cycle life of the battery module. Furthermore, if the internal pressure of a battery cell is too high, the battery module may suffer from thermal runaway. Utility Model Content

[0006] In order to solve the problem that different internal pressures of battery cells in the existing battery module will affect the cycle life of the battery module, and even if the internal pressure of a battery cell is too large, it will cause thermal runaway of the battery module, the first aspect of the utility model provides a battery cell.

[0007] The battery cell comprises a shell, a one-way air permeable membrane and an electrode assembly;

[0008] A one-way breathable membrane is provided on the shell;

[0009] The electrode assembly is located in the shell and connected to the polarity terminal on the top of the shell; the polarity terminal is provided with a mounting portion for mounting the heat exchange tube.

[0010] A one-way breathable membrane is arranged on the battery cell of the utility model, and the one-way breathable membrane can discharge the gas generated in the battery cell out of the battery cell housing. When the battery cell is assembled into a battery module, the gas pressure in the gas area of ​​each battery cell can be kept basically consistent, thereby ensuring the cycle life of the battery module and reducing the probability of thermal runaway of the battery module.

[0011] In addition, since the one-way breathable membrane is installed on the shell during the shell manufacturing process of the battery cell, when the battery cell is subjected to a formation treatment, the one-way breathable membrane can directly discharge the gas generated during the formation out of the shell. Compared with existing battery cells, this saves the steps of opening and sealing the battery cell when performing the formation treatment, thereby improving the manufacturing efficiency of the battery cell.

[0012] The battery cell polarity terminal of the utility model has a mounting portion for a heat exchange tube. When a plurality of battery cells are assembled into a battery module, the temperature of the electrode assembly in each battery cell can be transferred from the polarity terminal to an external temperature control device through the heat exchange tube, thereby reducing the problem of overheating of the electrode assembly affecting the performance of the battery module. More importantly, direct temperature control of each electrode assembly reduces the probability of thermal runaway, thereby improving safety.

[0013] Furthermore, the mounting portion is a groove arranged on the polarity terminal.

[0014] Furthermore, the housing comprises a top cover and an outer shell with one end open;

[0015] The top cover is fixed to the open end of the shell by welding;

[0016] The top cover comprises a cover body, a positive terminal and a negative terminal; the positive terminal and the negative terminal are fixedly insulated on the cover body; and a one-way air-permeable membrane is arranged on the cover body.

[0017] Based on the battery cell of the first aspect, the second aspect of the utility model further provides a battery module, the battery module comprising a gas chamber, a heat exchange tube and a plurality of battery cells of the first aspect;

[0018] Multiple battery cells are placed side by side;

[0019] A plurality of first through holes are provided on the gas chamber along the arrangement direction of the battery cells. The gas chamber is connected to the shells of the battery cells, and the plurality of first through holes of the gas chamber correspond to the one-way air permeable membranes of the battery cells one by one. The gas generated in each battery cell overflows into the gas chamber through the one-way air permeable membrane, so that the gas pressure in each battery cell remains consistent.

[0020] The heat exchange tube cooperates with the mounting portion of each battery cell polarity terminal.

[0021] The third aspect of the utility model provides another battery cell, which includes a shell, a hollow component, a one-way air permeable membrane and an electrode assembly;

[0022] The shell is provided with air holes;

[0023] Both ends of the hollow component are open, one end is connected to the shell area around the pore, and the other end is used to connect to the gas chamber; the one-way air permeable membrane is arranged in the pore or the hollow component; the electrode assembly is located in the shell and connected to the polarity terminal on the top of the shell; the polarity terminal is provided with a mounting portion for mounting a heat exchange tube.

[0024] Furthermore, the hollow component and the shell are integrally formed.

[0025] Furthermore, the mounting portion is a groove arranged on the polarity terminal.

[0026] Furthermore, the housing comprises a top cover and an outer shell with one end open; the top cover is fixed to the open end of the outer shell by welding;

[0027] The top cover comprises a cover body, a positive terminal, a negative terminal and a hollow component; the positive terminal and the negative terminal are fixedly insulated on the cover body; and the hollow component is arranged on the top cover.

[0028] A fourth aspect of the present utility model provides a battery module, the battery module comprising a gas chamber, a heat exchange tube and a plurality of battery cells according to the third aspect;

[0029] A plurality of battery cells are placed side by side, and the hollow components of each battery cell are connected to the gas chamber; the gas generated in each battery cell overflows into the gas chamber through the one-way air permeable membrane, so that the gas pressure in each battery cell remains consistent;

[0030] The heat exchange tube cooperates with the mounting portion of each battery cell polarity terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of the structure of a battery cell in Example 1;

[0032] Figure 2 is a schematic diagram of the structure of the battery module in Example 2;

[0033] Figure 3 is a schematic diagram of the structure of a battery cell in Example 3;

[0034] Figure 4 This is a schematic diagram of the structure of the battery module in Example 4;

[0035] Figure 5 This is an exploded view of the battery module in Example 4.

[0036] The reference numerals are as follows:

[0037] 1-shell, 11-top cover, 12-shell, 13-bottom cover, 2-one-way breathable membrane, 3-polarity terminal, 4-installation part, 5-hollow component;

[0038] 100 - battery cell, 200 - gas chamber, 201 - branch pipe, 300 - heat exchange tube. DETAILED DESCRIPTION

[0039] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments, not all of the embodiments. Based on the following embodiments, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this utility model.

[0040] At the same time, it should be noted that the orientations or positional relationships indicated by the terms "top, bottom, inside and outside" in the text are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the technical solution. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0041] In this utility model, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0042] The basic concept of the utility model is to provide a one-way breathable membrane on the shell of the battery cell, so that when the battery cell is used to form a battery module, there is no need to unpack the battery cell, thereby saving the production process of the battery module and improving the assembly efficiency of the battery module.

[0043] Example 1

[0044] like Figure 1 As shown, the battery cell 100 in this embodiment includes a housing 1, a one-way air permeable membrane 2, and an electrode assembly;

[0045] The shell 1 is provided with a one-way breathable membrane 2, which is used to discharge the gas generated in the battery cell out of the shell; the electrode assembly is located in the shell and connected to the polarity terminal 3 on the top of the shell 1; the polarity terminal 3 is provided with a mounting portion 4 for mounting a heat exchange tube.

[0046] The housing 1 is a component for forming an internal environment of the battery cell 100, wherein the formed internal environment can be used to accommodate the electrode assembly, electrolyte and other components. The housing 1 can be of various shapes and sizes, such as a rectangular parallelepiped. Specifically, the shape of the housing 1 can be determined according to the specific shape and size of the electrode assembly.

[0047] The shell 1 can be in the following two forms:

[0048] 1. The housing 1 comprises a top cover 11 and an outer shell 12 with an open top. The top cover 11 is provided with a positive terminal and a negative terminal of a battery cell. The top cover 11 is sealed and mounted on the outer shell 12 with an open top.

[0049] 2. The housing 1 includes a top cover 11, a bottom cover 13 and an outer shell 12 with both top and bottom openings; the top cover 11 is provided with positive and negative terminals of the battery cell; the top cover 11 is sealed and mounted on the top opening of the outer shell 12, and the bottom cover 13 is sealed and mounted on the bottom opening of the outer shell 12.

[0050] The electrode assembly is the part of the battery cell where the electrochemical reaction occurs. The housing may contain one or more electrode assemblies. The electrode assembly is also provided with tabs. During the charge and discharge process of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte. The electrode assembly is made of multiple layers of pole sheets by winding or laminating, and each layer of pole sheets includes a positive electrode sheet, a separator and a negative electrode sheet.

[0051] A one-way air permeable membrane 2 is provided on the shell, and the one-way air permeable membrane 2 can discharge the gas generated in the battery cell 100 out of the battery cell shell. When the battery cell 100 is used to assemble a battery module in which the gas areas of each battery cell 100 are connected, there is no need to unpack the battery cell for a second time, which saves the production process and improves the assembly efficiency.

[0052] Specifically, the one-way air permeable membrane 2 can be arranged on the top or side wall of the housing 1, and its location needs to correspond to the gas area of ​​the inner cavity of the battery cell 100, and this location needs to ensure that the gas in the battery cell can be discharged out of the housing. In this embodiment, the one-way air permeable membrane is arranged on the top of the housing.

[0053] The one-way air permeable membrane 2 can be installed on the battery cell 100 in the following two ways:

[0054] 1. It can be fixed on the shell 1 of the battery cell 100 by injection molding during the manufacturing process of the battery cell 100, that is, the battery cell 100 is a homemade battery, and no explosion relief mechanism is required on the battery cell 100; 2. It can also be modified by using a finished battery cell, that is, first opening an opening on the battery cell shell, and then fixing the one-way air permeable membrane 2 on the opening of the battery cell 100 shell (the explosion relief membrane of the finished battery cell can be removed first to form an opening, and then the one-way air permeable membrane is used to seal the opening).

[0055] Compared to the second method, since the one-way breathable membrane 2 is installed on the shell during the shell manufacturing process of the battery cell 100, when the battery cell is subjected to a formation treatment, the one-way breathable membrane 2 can directly discharge the gas generated during the formation to the outside of the shell 1. Compared with the existing battery cells, the steps of opening and sealing the battery cell when performing the formation treatment are saved, thereby improving the manufacturing efficiency of the battery cell.

[0056] The electrode assembly is located inside the shell and connected to the polarity terminal 3 on the top of the shell 1; a mounting portion 4 for mounting a heat exchange tube is provided on the polarity terminal 3; when a plurality of battery cells 100 are assembled into a battery module, the temperature of the electrode assembly in each battery cell 100 can be transferred from the polarity terminal to an external temperature control device through the heat exchange tube, thereby reducing the problem of overheating of the electrode assembly affecting the performance of the battery module. More importantly, direct temperature control of each electrode assembly reduces the probability of thermal runaway, thereby improving safety.

[0057] Specifically, the installation portion of the heat exchange tube in the present invention has two forms:

[0058] Method 1: A through hole is opened on the polarity terminal 3, and the through hole is arranged perpendicular to the axial direction of the polarity terminal 3; the aperture size of the through hole needs to ensure that the heat exchange tube is tightly clamped therein to ensure installation stability while ensuring the heat transfer effect between the heat exchange tube and the polarity terminal.

[0059] Method 2: A groove is provided on the top or side wall of the polarity terminal 3; the width of the groove needs to ensure that the heat exchange tube is tightly clamped therein, so as to ensure the installation stability while ensuring the heat transfer effect between the heat exchange tube and the pole.

[0060] Since the battery cell polarity terminal 3 is charged, in order to ensure safety, the heat exchange tube and the battery cell polarity terminal 3 must be insulated. The insulation can be maintained by oxidizing the heat exchange tube or providing an insulating layer in the area where the heat exchange tube contacts the polarity terminal.

[0061] When manufacturing the battery cell, a heat exchange tube can be installed on the polarity terminal of the battery cell before liquid injection. The heat exchange tube can be used to heat the electrode assembly. The generated gas can be discharged from the battery cell shell through the one-way breathable membrane, thereby controlling the water content of the electrode assembly and avoiding damage to the battery caused by hydrofluoric acid generated after water comes into contact with the electrolyte. Compared with the traditional vacuum baking method, this water removal method does not require a special vacuum baking box, reduces the production cost of the battery cell, and also improves the production efficiency of the battery cell.

[0062] Example 2

[0063] Based on the structure of the battery cell in Example 1, this embodiment discloses a battery module, including a gas chamber 200, a heat exchange tube 300 and a plurality of battery cells 100; the plurality of battery cells 100 are placed side by side;

[0064] A plurality of first through holes are provided on the gas chamber 200 along the arrangement direction of the battery cells. The gas chamber 200 is connected to the shells of the battery cells 100, and the plurality of first through holes of the gas chamber 200 correspond one by one to the one-way air permeable membrane 2 of the battery cells 100. The gas generated in each battery cell 100 overflows into the gas chamber 200 through the one-way air permeable membrane 2, so that the air pressure in each battery cell 100 remains consistent; the heat exchange tube 300 cooperates with the mounting portion of the polarity terminal of each battery cell.

[0065] Specifically, the gas chamber 200 can be a hollow tube with a rectangular cross-section, and its length matches the length of the battery module. In addition, the gas chamber 200 can be a box body, and multiple battery cells are located in the box body. The upper cover of the box body is a double-layer structure, that is, the upper cover of the box body is composed of two layers of cover plates, and the two layers of cover plates can be defined as an upper cover plate and a lower cover plate, respectively. There is a gap between the upper cover plate and the lower cover plate, and a plurality of first through holes are opened on the lower cover plate along the arrangement direction of the battery cells. The lower cover plate is connected to the shell of each battery cell, and the plurality of first through holes of the lower cover plate correspond one by one to the one-way air permeable membrane of the battery cell. The gas generated in each battery cell overflows into the gap through the one-way air permeable membrane, so that the air pressure in each battery cell remains consistent.

[0066] The heat exchange tube 300 can be specifically provided in the following ways:

[0067] 1. An aluminum tube is bent into a U-shaped structure, and two parallel tube sections are used to cooperate with the total positive electrode and the total negative electrode respectively, so as to realize the heat exchange between each battery cell and the external temperature control device, and the liquid inlet and liquid outlet of the aluminum tube are located on the same side; the transmission medium in the aluminum tube can be water, insulating oil or fluorinated liquid; or two aluminum tubes can be used to cooperate with the total positive electrode and the total negative electrode respectively.

[0068] 2. Two cored heat pipes are used to cooperate with the total positive electrode and the total negative electrode respectively, so as to realize the heat exchange between each battery cell and the external temperature control device. The cored heat pipe is an evaporation-condensation type heat exchange device, which realizes heat transfer by the state change of the working fluid in the pipe.

[0069] Since the heat transfer effect of the cored heat pipe is affected by the length of the cored heat pipe, when the number of battery cells in the battery module is large (that is, the length of the battery module is long), the use of the cored heat pipe will be limited. Therefore, in this embodiment, aluminum tubes are preferably selected as heat exchange tubes. If the insulation between the heat exchange tubes and the polarity terminals can be effectively ensured, water can be preferably used as the heat transfer medium flowing in the aluminum tube from the aspects of heat transfer efficiency and cost.

[0070] Example 3

[0071] The structure of the battery cell in this embodiment is basically the same as that of the battery cell in Embodiment 1, except that the battery cell 100 is provided with an air hole and a hollow member 5 on the shell; both ends of the hollow member 5 are open, one end of which is connected to the shell area around the air hole, and the other end is used to connect to the gas chamber 200; the one-way air permeable membrane 2 is provided in the air hole or the hollow member 5;

[0072] The hollow member 5 of this embodiment is an integral part with the shell 1. After forming a battery cell, the hollow member 5 and the shell 1 are both charged. Therefore, for the safety when the hollow member and the gas chamber are connected, the gas chamber can be made of insulating material, or the hollow member 5 and the gas chamber can be connected by a hollow connector made of insulating material. One end of the hollow connector can be sleeved inside the hollow member 5, and the other end can extend out of the hollow member 5 for connection with the gas chamber; one end of the hollow connector can also be sleeved outside the hollow member 5, and the other end can extend out of the hollow member 5 for connection with the gas chamber. The hollow connector can be made of plastic material with high temperature resistance (thermal runaway temperature), such as PP or PE material, that is, PP or PE pipe can be used as the hollow connector.

[0073] The insulation between the hollow component 5 and the gas chamber can also be achieved by applying an insulating coating on the inner and outer surfaces of the hollow component 5 . However, compared with the present embodiment, the process is more complicated and the cost is higher.

[0074] In some other embodiments, the hollow member 5 and the shell are separate; the hollow member 5 can generally be fixed to the shell by welding, riveting or injection molding.

[0075] If welding or riveting is adopted, usually, the material of the hollow component 5 is the same as that of the shell. When assembling the battery module, the insulation between the hollow component 5 and the shell, as well as the gas chamber, also needs to be considered.

[0076] Example 4

[0077] Based on the structure of the battery cell in Example 3, this embodiment discloses a battery module, including a gas chamber 200, a heat exchange tube 300 and a plurality of battery cells 100;

[0078] A plurality of battery cells 100 are placed side by side (the specific electrical connection method may be a plurality of battery cells connected in series or a plurality of battery cells connected in parallel), and the hollow component 5 of each battery cell 100 is connected to the gas chamber 200; the gas generated in each battery cell 100 overflows into the gas chamber 200 through the one-way air permeable membrane 2, so that the gas pressure in each battery cell remains consistent; the heat exchange tube 300 cooperates with the mounting portion of the polarity terminal of each battery cell 100.

[0079] Through holes corresponding to the hollow components 5 of each battery cell can be opened on the gas chamber 200, and the hollow components 5 can be inserted into the through holes to achieve the connection between the hollow components 5 and the gas chamber 200. Branch pipes 201 can also be added at the through holes of the gas chamber 200 to communicate with the corresponding hollow components 5 through the branch pipes 201. When the hollow components 5 and the battery cell shell are integrated into one piece and the battery cell is formed, when the hollow components 5 and the shell are both charged, in order to improve safety performance, an insulated gas chamber 200 and the hollow components can be connected.

Claims

1. A battery cell, characterized in that: It includes a shell, a one-way breathable membrane and an electrode assembly; A one-way breathable membrane is provided on the shell; The electrode assembly is located in the shell and connected to the polarity terminal on the top of the shell; the polarity terminal is provided with a mounting portion for mounting the heat exchange tube.

2. The battery cell according to claim 1, characterized in that: The mounting portion is a groove arranged on the polarity terminal.

3. The battery cell according to claim 1 or 2, characterized in that: The housing comprises a top cover and an outer shell with one end open; The top cover is fixed to the open end of the shell by welding; The top cover comprises a cover body, a positive terminal and a negative terminal; the positive terminal and the negative terminal are fixedly insulated on the cover body; and a one-way air-permeable membrane is arranged on the cover body.

4. A battery module, characterized in that: comprising a gas chamber, a heat exchange tube, and a plurality of battery cells as claimed in claim 1; Multiple battery cells are placed side by side; A plurality of first through holes are provided on the gas chamber along the arrangement direction of the battery cells. The gas chamber is connected to the shells of the battery cells, and the plurality of first through holes of the gas chamber correspond to the one-way air permeable membranes of the battery cells one by one. The gas generated in each battery cell overflows into the gas chamber through the one-way air permeable membrane, so that the gas pressure in each battery cell remains consistent. The heat exchange tube cooperates with the mounting portion of each battery cell polarity terminal.

5. A battery cell, characterized in that: It includes a shell, a hollow component, a one-way air permeable membrane and an electrode assembly; The shell is provided with air holes; The hollow member has open ends, one end of which is connected to the shell region around the air hole, and the other end is used to connect to the gas chamber; The one-way breathable membrane is arranged in the air hole or the hollow component; The electrode assembly is located in the shell and connected to the polarity terminal on the top of the shell; the polarity terminal is provided with a mounting portion for mounting the heat exchange tube.

6. The battery cell according to claim 5, characterized in that: The hollow component is formed integrally with the shell.

7. The battery cell according to claim 5 or 6, characterized in that: The mounting portion is a groove arranged on the polarity terminal.

8. The battery cell according to claim 7, characterized in that: The housing comprises a top cover and an outer shell with one end open; The top cover is fixed to the open end of the shell by welding; The top cover comprises a cover body, a positive terminal, a negative terminal and a hollow component; the positive terminal and the negative terminal are fixedly insulated on the cover body; and the hollow component is arranged on the top cover.

9. A battery module, characterized in that: comprising a gas chamber, a heat exchange tube, and a plurality of battery cells as claimed in claim 5; A plurality of battery cells are placed side by side, and the hollow components of each battery cell are connected to the gas chamber; the gas generated in each battery cell overflows into the gas chamber through the one-way air permeable membrane, so that the gas pressure in each battery cell remains consistent; The heat exchange tube cooperates with the mounting portion of each battery cell polarity terminal.

Images