Battery cells and their cell modules and battery packs

Abstract

This utility model discloses a battery cell, a battery cell module therein, and a battery pack, belonging to the field of batteries. The battery cell includes a cell housing, a cell body, a first insulating layer, and a supporting structure disposed within the cell housing. The cell housing has a vent, and the cell body has an exhaust port. The first insulating layer is attached to the outer surface of the cell body. The supporting structure is disposed between the inner wall of the cell housing and the first insulating layer, forming a gap between the inner wall of the cell housing and the first insulating layer, and creating an exhaust channel connecting the exhaust port and the exhaust port. Compared to existing technologies, this utility model not only facilitates the rapid discharge of harmful gases escaping from the battery cell but is also easier to implement in terms of process. Furthermore, by adjusting the gap, this utility model also facilitates matching the volume of the exhaust channel with the energy density of the battery, thereby improving battery safety.

Description

Technical Field

[0001] This utility model belongs to the field of batteries, and in particular relates to a battery cell, a battery cell module and a battery pack having the same. Background Technology

[0002] Generally, there is a significant trade-off between the safety of a battery cell and the energy density of the battery; that is, the higher the energy density of the battery, the worse the safety of the cell. Currently, to balance energy density and safety performance, battery cells typically have openable venting structures (such as rupture membranes and explosion-proof valves) to allow harmful gases (such as CO) generated by cell malfunctions (such as thermal runaway) to escape from the cell. However, existing technologies cannot quickly expel harmful gases escaping from the cell, resulting in low venting efficiency and compromised safety. Utility Model Content

[0003] In view of this, the purpose of this utility model is to provide a battery cell and a battery cell module and battery pack having the same, so as to solve at least one of the above technical problems.

[0004] To achieve the above-mentioned technical objectives, the first aspect of this utility model provides a battery cell, the battery cell comprising a battery cell housing and a battery cell body, a first insulating layer and a support structure disposed within the battery cell housing, the battery cell housing having an exhaust port, the battery cell body having an vent, the first insulating layer being attached to the outer surface of the battery cell body, and the support structure being disposed between the inner wall of the battery cell housing and the first insulating layer, thereby forming a gap between the inner wall of the battery cell housing and the first insulating layer, and forming an exhaust channel connecting the vent and the exhaust port.

[0005] In one embodiment, the support structure includes a support body and a support base. The support body is attached to the first insulating layer and includes multiple support plates arranged in layers and connected together. The support base is supported between the support body and the inner wall of the battery cell housing, thereby forming the gap between the inner wall of the battery cell housing and the first insulating layer.

[0006] In one embodiment, the plurality of support plates include at least two insulating support plates and at least one bending support plate, with at least one bending support plate provided between each pair of adjacent insulating support plates.

[0007] In one embodiment, each of the insulating support plates and each of the bending support plates is provided with at least one through hole corresponding to the exhaust port.

[0008] In one embodiment, the support structure is integrally connected to the cell housing and protrudes from the inner wall of the cell housing.

[0009] In one embodiment, the cell housing and the cell body are blade-shaped, the cell housing has the exhaust port on its long side, the cell body has the vent on its short side, the support structure is disposed between the inner wall of the long side of the cell housing and the first insulating layer, and the exhaust channel extends along the length of the cell housing and connects the vent and the exhaust port.

[0010] In one embodiment, a second insulating layer is further included, which is attached to the outer surface of the cell housing.

[0011] In one embodiment, the gap is 0.1 mm to 1 mm.

[0012] A second aspect of this utility model provides a battery cell module, including the battery cell described in the above technical solution.

[0013] A third aspect of this utility model provides a battery pack, including the cell module as described in the above technical solution.

[0014] By adopting the above technical solution, this utility model has the following beneficial effects:

[0015] This invention features a support structure between the inner wall of the battery cell casing and the first insulating layer, creating a gap between them and forming an exhaust channel connecting the vent and the exhaust port. Compared to existing technologies, this invention not only facilitates the rapid discharge of harmful gases escaping from the battery cell but is also easier to implement in the manufacturing process. Furthermore, by adjusting the gap, this invention allows the volume of the exhaust channel to be matched with the energy density of the battery, thereby improving battery safety. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a battery cell provided in an embodiment of this application from a first-view perspective.

[0018] Figure 2 This is a schematic diagram of a battery cell provided in an embodiment of this application from a second-view perspective.

[0019] Figure 3 This is a schematic diagram of a battery cell from a third-person perspective, provided as an embodiment of this application.

[0020] Figure 4 An exploded view of a battery cell provided in an embodiment of this application from a first-view perspective.

[0021] Figure 5 An exploded view of a battery cell provided in an embodiment of this application from a second-view perspective.

[0022] Figure 6 This is a schematic diagram of a battery cell support structure provided in an embodiment of this application.

[0023] Figure 7 A cross-sectional view of a battery cell in the AA direction provided in an embodiment of this application.

[0024] Figure 8 A cross-sectional view of another battery cell in the AA direction provided for an embodiment of this application.

[0025] Figure 9 This is a schematic diagram of a battery cell support structure provided in an embodiment of this application.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1. Battery cell;

[0028] 11. Cell body; 12a. First insulation layer; 12b. Second insulation layer; 13. 13a. 13b. Support structure; 14. Cell casing; 15. Explosion-proof structure; 16. Venting channel;

[0029] 111. Positive electrode top cover patch; 112. Positive electrode; 113. Positive electrode spacer; 114. Electrode core assembly; 115. Negative electrode spacer; 116. Negative electrode; 117. Negative electrode top cover patch; 118. Vent;

[0030] 131. Support body; 132. Support base; 133. Insulating support plate; 134. Bending support plate; 135. First through hole; 136. Second through hole;

[0031] 141. Exhaust port;

[0032] 151. Explosion-proof valve; 152. Anti-corrosion layer; 153. Air outlet. Detailed Implementation

[0033] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the description of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0034] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0035] The terms “upper,” “lower,” “left,” “right,” “front,” “back,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0036] The terms “first,” “second,” “third,” etc., are used merely to distinguish elements with similar properties, not to indicate or imply relative importance or a specific order.

[0037] The terms “include,” “comprising,” or any other variation thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0038] Generally speaking, there is a significant contradiction between the safety of a battery cell and the energy density of the battery; that is, the higher the energy density of the battery, the worse the safety of the battery cell.

[0039] Currently, to balance energy density and safety performance, battery cells typically have openable venting structures (such as rupture membranes and explosion-proof valves) to allow harmful gases (such as CO) generated by malfunctions (such as thermal runaway, overcharging, or external forces) to escape from the cell. However, existing technologies cannot quickly expel harmful gases escaping from the cell, resulting in low venting efficiency and compromised safety.

[0040] To address the issues of low exhaust efficiency and poor safety in existing battery cells, it is necessary to improve or optimize the cell structure.

[0041] Example 1

[0042] Please see Figure 1 , Figure 2 The first aspect of this utility model provides a battery cell. Overall, the battery cell 1 is rectangular parallelepiped in shape, but is not limited thereto. One end of the battery cell 1 is a positive electrode structure, and the other end is a negative electrode structure, used for storing and releasing electrical energy through an electrochemical reaction.

[0043] For example, such as Figures 3 to 7 As shown, the battery cell 1 includes a battery cell body 11, a first insulating layer 12a, a support structure 13, and a battery cell housing 14. The battery cell body 11, the first insulating layer 12a, and the support structure 13 are installed inside the battery cell housing 14. Specifically, the first insulating layer 12a is attached to the outer surface of the battery cell body 11, and the support structure 13 is installed between the inner wall of the battery cell housing 14 and the first insulating layer 12a. It should be noted that, to address the problem of harmful gases escaping from the battery cell body 11 accumulating inside the battery cell housing 14, the battery cell body 11 has an vent 118, and the battery cell housing 14 has an exhaust port 141. The support structure 13 creates a gap between the inner wall of the battery cell housing 14 and the first insulating layer 12a, forming an exhaust channel 16 connecting the vent 118 and the exhaust port 141. It is worth mentioning that the vent 118 mainly refers to the normally open vents at both ends of the battery cell body 11, such as the gaps at the joints of different components at the left and right ends of the battery cell body 11.

[0044] For example, such as Figure 4 , Figure 5 As shown, the battery cell body 11 includes a positive electrode top cover patch 111, a positive electrode 112, a positive electrode spacer 113, a core assembly 114, a negative electrode spacer 115, a negative electrode 116, and a negative electrode top cover patch 117. The positive electrode top cover patch 111, the positive electrode 112, and the positive electrode spacer 113 are installed at one end of the core assembly 114, forming the positive electrode structure of the battery cell 1; the negative electrode spacer 115, the negative electrode 116, and the negative electrode top cover patch 117 are installed at the other end of the core assembly 114, forming the negative electrode structure of the battery cell 1. Specifically, the positive electrode 112 is installed between the positive electrode top cover patch 111 and the positive electrode spacer 113, and is connected to the core assembly 114 through the positive electrode spacer 113; the negative electrode 116 is installed between the negative electrode spacer 115 and the negative electrode top cover patch 117, and is connected to the core assembly 114 through the negative electrode spacer 115. Preferably, the positive electrode top cover patch 111 and the negative electrode top cover patch 117 are made of insulating materials, such as PP (Polypropylene) and PET (Polyethylene terephthalate). It should be noted that the electrode core assembly 114 mentioned here is the core component inside the battery cell body 11 that realizes the electrochemical reaction, and it includes at least a separator and an electrolyte. The separator is a porous film that allows charge carriers (such as lithium ions) to permeate, and is used to isolate the positive electrode 112 and the negative electrode 116 to prevent short circuits. The electrolyte is used to transfer charge carriers between the positive electrode 112 and the negative electrode 116 to realize the storage and release of electrical energy; it is mainly located inside the electrode core assembly 114, and a small amount is located between the inner wall of the battery cell housing 14 and the first insulating layer 12a.

[0045] Preferably, the cell body 11 is blade-shaped, and the vent 118 is formed on the short side of the cell body 11, such as the gap at the connection between the core assembly 114 and the positive electrode spacer 113, and the gap at the connection between the core assembly 114 and the negative electrode spacer 115.

[0046] For example, the first insulating layer 12a is made of an insulating material such as a polyester polymer, or Mylar film.

[0047] For example, the support structure 13 is a composite structure, including a support body 131 and a support base 132. The support body 131 is attached to the first insulating layer 12a, and includes multiple support plates arranged in a stacked and connected manner. The support base 132 is supported between the support body 131 and the inner wall of the battery cell housing 14, creating a gap between the inner wall of the battery cell housing 14 and the first insulating layer 12a. Specifically, the support body 131 includes at least two insulating support plates 133 and at least one bending-resistant support plate 134, with at least one bending-resistant support plate 134 between every two adjacent insulating support plates 133. In this first embodiment, the support body 131 includes two insulating support plates 133 and one bending-resistant support plate 134. One of the two insulating support plates 133 is connected to the first insulating layer 12a, and the other of the two insulating support plates 133 is connected to the support base 132. The bending-resistant support plate 134 is connected between the two insulating support plates 133. Preferably, the two insulating support plates 133 and the one bending support plate 134 are connected in pairs by means of adhesive bonding, hot melting, laser welding, and brazing to form the support body 131, and then connected to the support base 132 and the first insulating layer 12a. In some embodiments, there may be multiple support bases 132. In this first embodiment, there are two support bases 132, which are respectively set at the left and right ends of one of the two insulating support plates 133.

[0048] To improve the strength of the battery cell 1, preferably, the bending strength of the bending support plate 134 is greater than that of the insulating support plate 133.

[0049] To ensure safety, preferably, the insulating support plate 133 and the support base 132 are made of insulating materials such as PP, PET, and ceramics.

[0050] For example, such as Figure 6As shown, each insulating support plate 133 and each bending support plate 134 is provided with at least one through hole corresponding to the vent 141. The through hole formed on the insulating support plate 133 can be referred to as the first through hole 135, and the through hole formed on the bending support plate 134 can be referred to as the second through hole 136. Preferably, the first through hole 135 and the second through hole 136 partially overlap, and the areas of both the first through hole 135 and the second through hole 136 are greater than or equal to the corresponding area of ​​the vent 141. This facilitates the rapid discharge of harmful gases escaping from the cell body 11, preventing the accumulation of harmful gases within the cell casing 14, thereby solving the problem of the cell casing 14 cracking due to excessive gas pressure.

[0051] For example, such as Figure 7 As shown, in order to reduce the space occupied by the support structure 13 itself in the exhaust channel 16, the width of the first insulating layer 12a is greater than the corresponding widths on the insulating support plate 133, the bending support plate 134, and the support base 132; the width of the bending support plate 134 is less than the corresponding widths on the insulating support plate 133 and the support base 132; and the length of the bending support plate 134 is less than the corresponding length on the insulating support plate 133. Preferably, the length of the support base 132 is greater than the difference between the lengths of the insulating support plate 133 and the bending support plate 134, and the length of the bending support plate 134 is less than or equal to one-third of the length of the first insulating layer 12a.

[0052] According to the inventors, preferably, the gap between the inner wall of the cell housing 14 and the first insulating layer 12a is 0.1mm to 1mm. Specifically, the gap between the inner wall of the cell housing 14 and the first insulating layer 12a refers to the sum of the thicknesses of the insulating support plate 133, the bending support plate 134, and the support base 132, such as 0.1mm, 0.5mm, 1mm, etc.

[0053] For example, such as Figure 5 , Figure 7As shown, the cell housing 14 is rectangular or blade-shaped. An exhaust port 141 is formed on the long side of the cell housing 14. A support structure 13 is disposed between the inner wall of the long side of the cell housing 14 and the first insulating layer 12a. An exhaust channel 16 extends along the length of the cell housing 14 and connects the vent 118 and the exhaust port 141. It is worth noting that the cell housing 14 mentioned here is a charged housing, which can be made of conductive materials such as copper or aluminum, used to connect the cell body 11 to the charging or discharging circuit, and to protect the cell body 11. Preferably, the exhaust port 141 is formed at the lower part of the cell housing 14, such as on the lower long side of the cell housing 14. Thus, when the cell 1 is installed at a predetermined position on the vehicle body, if the cell 1 malfunctions, the harmful gases escaping from the cell 1 are discharged to the lower part of the cell 1 through the exhaust port 141, rather than diffused into the vehicle's passenger compartment, which helps ensure the safety of the occupants.

[0054] Furthermore, the battery cell 1 also includes a second insulating layer 12b for electrical isolation, such as preventing short circuits. Specifically, the second insulating layer 12b is attached to the outer surface of the battery cell housing 14. Preferably, the second insulating layer 12b is made of an insulating material such as a polyester polymer, like a Mylar film.

[0055] Furthermore, according to the inventors, in order to match the opening or closing of the exhaust port 141 with application requirements—for example, the exhaust port 141 is closed when the battery cell 1 is working normally, and open when the battery cell 1 malfunctions—in this embodiment, the battery cell 1 also includes an explosion-proof structure 15 (such as a rupture membrane, explosion-proof valve, etc.). The explosion-proof structure 15 is installed in the exhaust port 141, meaning the location of the exhaust port 141 is the installation location of the explosion-proof structure 15. Specifically, the explosion-proof structure 15 includes an explosion-proof valve 151 and an anti-corrosion layer 152. The explosion-proof valve 151 has an outlet 153 connected to the exhaust channel 16 and the vent 118. The anti-corrosion layer 152 is used to isolate the small amount of electrolyte between the battery cell housing 14 and the first insulating layer 12a from contact with the explosion-proof valve 151, preventing corrosion of the explosion-proof valve 151 and protecting it. Thus, when cell 1 is operating normally, the explosion-proof valve 151 is in the closed state; when cell 1 malfunctions, the explosion-proof valve 151 and the anti-corrosion layer 152 rupture outwards from the cell housing 14 under the pressure of harmful gases escaping from the cell body 11, thereby rapidly releasing the pressure accumulated inside the cell housing 14 to the external environment. This also facilitates the staff in determining the operating status of cell 1.

[0056] It is worth mentioning that the small amount of electrolyte between the aforementioned cell casing 14 and the first insulating layer 12a is used to replenish the electrolyte in the electrode core assembly 114. That is, when the electrolyte in the electrode core assembly 114 is insufficient, the small amount of electrolyte will seep into the electrode core assembly 114 through the first insulating layer 12a to replenish it.

[0057] Example 2

[0058] The second aspect of this utility model also provides a battery cell, most of which are the same as the battery cell 1 of the aforementioned embodiment 1. The difference lies in that the support structure 13a of the battery cell of this embodiment 2 is structurally different from the support structure 13 of the battery cell 1 of embodiment 1. The following is a detailed description.

[0059] like Figure 1 , Figure 4 and Figure 8 As shown, in Embodiment 2, the support structure 13a has a convex structure such as a column or protrusion, and it is integrally connected with the cell housing 14. Specifically, the support structure 13a is formed on the inner wall of the cell housing 14 and protrudes towards the first insulating layer 12a to support the first insulating layer 12a and the cell body 11. Preferably, the protrusion from the plane of the inner wall of the cell housing 14 towards the first insulating layer 12a is 0.1mm to 1mm, that is, the support height of the support structure 13a itself is 0.1mm to 1mm, such as 0.1mm, 0.5mm, 1mm, etc. This also allows a gap to be formed between the inner wall of the cell housing 14 and the first insulating layer 12a, and forms an exhaust channel 16 connecting the vent 118 and the exhaust port 141, solving the problem of low safety due to low exhaust efficiency in existing cells.

[0060] Example 3

[0061] The third aspect of this utility model also provides a battery cell, most of which are the same as the battery cell 1 of the first embodiment and the battery cell of the second embodiment. The difference is that the support structure 13b of the battery cell of this third embodiment is structurally different from the support structure 13 of the battery cell 1 of the first embodiment and the support structure 13a of the battery cell of the second embodiment. The following is a detailed description.

[0062] like Figure 9As shown, in Embodiment 3, the supporting structure 13b of the battery cell refers to the overlapping side of the first insulating layer 12a. That is, the gap between the inner wall of the battery cell housing 14 and the first insulating layer 12a, and the formation of the exhaust channel 16 connecting the vent 118 and the exhaust port 141 are based on the overlapping side of the first insulating layer 12a. The overlapping side of the first insulating layer 12a faces the surface where the explosion-proof structure 15 or the exhaust port 141 is located. Specifically, when the first insulating layer 12a wraps the battery cell body 11, the two opposing long side edges of the first insulating layer 12a partially overlap on one long side of the battery cell body 11, making the thickness of the first insulating layer 12a on this long side inconsistent. That is, the thickness of the overlapping portion and the non-overlapping portion of the two opposing long side edges of the first insulating layer 12a are inconsistent, thereby forming a gap between the inner wall of the battery cell housing 14 and the first insulating layer 12a, and forming the exhaust channel 16 connecting the vent 118 and the exhaust port 141. This implementation method can also solve the problem of low safety in existing battery cells due to low exhaust efficiency.

[0063] Example 4

[0064] An embodiment of the fourth aspect of this utility model provides a battery cell module comprising the battery cells described in any of the foregoing embodiments. This is beneficial for enabling the battery cell module to balance energy density and safety performance.

[0065] Example 5

[0066] A fifth aspect of this utility model provides a battery pack comprising a cell module as described in Embodiment 4. This is beneficial in giving the battery pack a higher level of safety.

[0067] Furthermore, the battery pack also includes a battery management system. This system communicates with the cell modules. Notably, the battery management system, used for real-time monitoring and management of several cell modules, may include a master control unit and slave control units. The master control unit processes data from the various slave control units and executes advanced control algorithms, such as state estimation, fault diagnosis, and charging strategies. The slave control units monitor a certain number of cell modules, collecting voltage, current, and temperature data, and transmit this information to the master control unit. The communication connections include, but are not limited to, wireless (e.g., Bluetooth) connections, wired connections, fiber optic connections, RF connections, or any suitable combination thereof.

[0068] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the appended claims.

Claims

1. A battery cell, characterized in that, The battery includes a battery housing (14) and a battery body (11), a first insulating layer (12a), and a support structure (13, 13a, 13b) disposed within the battery housing (14). The battery housing (14) is provided with an exhaust port (141), and the battery body (11) is provided with an vent (118). The first insulating layer (12a) is attached to the outer surface of the battery body (11). The support structure (13, 13a, 13b) is disposed between the inner wall of the battery housing (14) and the first insulating layer (12a), thereby forming a gap between the inner wall of the battery housing (14) and the first insulating layer (12a), and forming an exhaust channel (16) connecting the vent (118) and the exhaust port (141).

2. The battery cell as described in claim 1, characterized in that, The support structure (13, 13a, 13b) includes a support body (131) and a support base (132). The support body (131) is attached to the first insulating layer (12a), and the support body (131) includes multiple support plates arranged in layers and connected together. The support base (132) is supported between the support body (131) and the inner wall of the cell housing (14), so that the gap is formed between the inner wall of the cell housing (14) and the first insulating layer (12a).

3. The battery cell as described in claim 2, characterized in that, The plurality of support plates include at least two insulating support plates (133) and at least one bending support plate (134), with at least one bending support plate (134) provided between each two adjacent insulating support plates (133).

4. The battery cell as described in claim 3, characterized in that, Each of the insulating support plates (133) and each of the bending support plates (134) is provided with at least one through hole corresponding to the vent (141).

5. The battery cell as described in claim 1, characterized in that, The support structure (13, 13a, 13b) is integrated with the cell housing (14) and protrudes from the inner wall of the cell housing (14).

6. The battery cell as described in claim 1, characterized in that, The battery cell housing (14) and the battery cell body (11) are blade-shaped. The battery cell housing (14) has the exhaust port (141) on its long side and the battery cell body (11) has the vent (118) on its short side. The support structure (13, 13a, 13b) is located between the inner wall of the long side of the battery cell housing (14) and the first insulating layer (12a). The exhaust channel (16) extends along the length of the battery cell housing (14) and connects the vent (118) and the exhaust port (141).

7. The battery cell as described in claim 1, characterized in that, It also includes a second insulating layer (12b), which is attached to the outer surface of the cell housing (14).

8. The battery cell as described in claim 1, characterized in that, The gap is 0.1mm to 1mm.

9. A battery cell module, characterized in that, Includes the battery cell as described in any one of claims 1 to 8.

10. A battery pack, characterized in that, Includes the battery cell module as described in claim 9.

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