Power battery

Abstract

A power battery, relating to the technical field of batteries. The power battery comprises a case (1), a cover plate (2), an electrode assembly (3), and an electrolyte injection hole (4). The case (1) comprises an accommodating cavity and a connecting channel; the cover plate (2) covers an end of the case (1); the electrode assembly (3) is arranged inside the accommodating cavity; two ends of the connecting channel are communicated with the accommodating cavity; the electrolyte injection hole (4) is formed on the case (1); the electrolyte injection hole (4) is communicated with the connecting channel. The power battery further comprises a side plate (6). The side plate (6) is arranged inside the case (1); the side plate (6) divides the interior of the case (1) into the accommodating cavity and the connecting channel. According to the power battery, during electrolyte injection, an electrolyte passes through the connecting channel and flows to two ends of the accommodating cavity, and then the electrode assembly (3) is wetted in a direction from two ends of the electrode assembly (3) to the middle of the electrode assembly (3), thereby shortening the electrolyte wetting path.

Description

Power Battery

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application with application number CN202321690140.7 and name “Power Battery” filed with the Patent Office of China on June 29, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a power battery. Background Art

[0004] Energy density and safety are two key characteristics of power batteries that attract significant attention. Regarding safety, to prevent explosions in the event of thermal runaway, traditional power batteries feature explosion-proof valves on their covers. The valve's opening pressure is lower than the pressure required to cause the battery housing to explode. When the internal pressure reaches the valve's opening pressure, the valve opens first, relieving the pressure inside the battery. To increase the energy density of power battery packs, batteries are designed into elongated strips that can be placed directly inside the pack, eliminating the need for a cell-to-module transition and improving space utilization.

[0005] However, in existing long-shaped power batteries, the injection hole is set on the cover plate. When the power battery is injected with electrolyte, the electrolyte infiltrates from one end of the electrode group in the longitudinal direction to the other end in the longitudinal direction, and the electrolyte infiltration path is long.

[0006] Application Contents

[0007] In view of this, the present application provides a power battery to solve the problem of long electrolyte infiltration path in existing power batteries.

[0008] The present application provides a power battery, which includes a shell, a cover plate, an electrode group and an injection hole. The shell includes a accommodating chamber and a connecting channel. The cover plate is arranged at an end of the shell, the electrode group is arranged inside the accommodating chamber, and the connecting channel is connected to the accommodating chamber; the injection hole is arranged in the shell, and the injection hole is connected to the connecting channel; the power battery also includes a side plate, which is arranged inside the shell, and the side plate separates the interior of the shell into the accommodating chamber and the connecting channel.

[0009] Furthermore, the shell includes two first plates and two second plates, the first plates and the second plates are alternately connected, the first plates are perpendicular to the first direction, the second plates are perpendicular to the second direction, and the first direction is perpendicular to the second direction; the surface area of ​​the first plate is smaller than the surface area of ​​the second plate, and the injection hole is arranged on the first plate.

[0010] Furthermore, the number of the liquid injection hole is one, and the distance between the liquid injection hole and two ends of the first plate in the third direction is greater than 1 / 3 of the length of the first plate in the third direction.

[0011] Furthermore, the number of the injection holes is greater than or equal to two, and the distance between the centers of any two of the injection holes is greater than or equal to 2 mm.

[0012] Furthermore, the power battery further includes an explosion-proof valve, which is provided on the same first plate as the liquid injection hole, and a distance between an edge of the explosion-proof valve and a center of the liquid injection hole in the second direction is greater than or equal to 1 mm.

[0013] Furthermore, the side plate includes a plate body and a support portion, the plate body includes a first plane and a second plane opposite to each other, the first plane and the second plane are both perpendicular to the first direction, the support portion is fixed to the first plane, and the support portion abuts against the shell, the first plane and the shell enclose the connecting channel, and the second plane and the shell enclose the accommodating cavity.

[0014] Furthermore, the plate body is provided with guide holes at both ends in the third direction, the guide holes penetrate the plate body along the first direction, and the guide holes communicate with the accommodating cavity and the connecting channel.

[0015] Furthermore, a plurality of heat dissipation holes are formed on the plate body, and the heat dissipation holes penetrate the plate body along the first direction, and the orthographic projection of the liquid injection hole on the plate body is located outside the heat dissipation holes.

[0016] Furthermore, the area of ​​the first plane where the heat dissipation holes are not provided is 20%-80% of the area of ​​the first plane.

[0017] In the power battery of the present application, the electrode assembly is disposed within the accommodating cavity, with both ends of the connecting channel communicating with the accommodating cavity. A liquid injection hole is provided on the side panel and communicates with the connecting channel. During liquid injection, the electrolyte flows through the connecting channel into the accommodating cavity, and then infiltrates from the center of the electrode assembly toward both ends of the electrode assembly, thereby shortening the electrolyte infiltration path. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0019] FIG1 is a schematic diagram showing the three-dimensional structure of a power battery according to an embodiment of the present application;

[0020] FIG2 is a schematic diagram showing a planar structure of a power battery according to an embodiment of the present application;

[0021] FIG3 shows a cross-sectional view of the power battery in FIG2 taken along the line AA′;

[0022] FIG4 shows an enlarged view of portion B in FIG3 ;

[0023] FIG5 is a schematic diagram showing a planar structure of a side panel;

[0024] FIG6 is a schematic diagram showing the three-dimensional structure of the side panel;

[0025] FIG. 7 is an enlarged view of portion C in FIG. 6 .

[0026] Icon: 1-shell; 11-first plate; 12-second plate; 2-cover plate; 3-pole group; 4-liquid injection hole; 5-pole column; 6-side plate; 61-plate body; 62-support part; 63-guide hole; 64-heat dissipation hole; 7-explosion-proof valve; L1-first direction; L2-second direction; L3-third direction. DETAILED DESCRIPTION

[0027] The following detailed description is provided to help the reader gain a comprehensive understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent upon understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein. Rather, except for operations that must occur in a particular order, changes may be made that will be apparent upon understanding the disclosure of this application. Furthermore, descriptions of features known in the art may be omitted for clarity and brevity.

[0028] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways to implement the methods, devices, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0029] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being “on,” “connected to,” “coupled to,” “over,” or “overlaying” another element, it may be directly “on,” “connected to,” “coupled to,” “over,” or “overlaying” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on,” “directly connected to,” “directly coupled to,” “directly over,” or “directly covering” another element, there may be no other elements intervening therebetween.

[0030] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0031] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are used only to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Thus, a first member, component, region, layer, or portion in the examples described herein may also be referred to as a second member, component, region, layer, or portion without departing from the teachings of the examples.

[0032] For ease of description, spatial relational terms such as "above," "upper," "below," and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatial relational terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element would subsequently be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientations "above" and "below," depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relational terms used herein will be interpreted accordingly.

[0033] The terms used herein are intended only to describe various examples and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the singular is intended to include the plural. The terms "comprise," "include," and "have" list the presence of stated features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0034] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the drawings may occur. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include changes in shapes that occur during manufacturing.

[0035] The features of the examples described herein can be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0036] The power battery of the present application will be described below with reference to FIG1 to FIG7 . In FIG1 to FIG7 , the first direction L1 is the width direction of the power battery, the second direction L2 is the thickness direction of the power battery, and the third direction L3 is the length direction of the power battery.

[0037] The present application provides a power battery, as shown in Figures 1 to 4. The power battery includes a housing 1, a cover plate 2, an electrode group 3, and an injection hole 4. The housing 1 includes a receiving cavity and a connecting channel. The cover plate 2 is provided at the end of the housing 1. The electrode group 3 is disposed within the receiving cavity. Both ends of the connecting channel communicate with the receiving cavity. The injection hole 4 is provided in the housing 1 and communicates with the connecting channel. During injection, the electrolyte infiltrates from the middle of the electrode group 3 toward both ends of the electrode group 3, thereby shortening the electrolyte infiltration path.

[0038] As shown in Figure 1, the housing 1 includes two first plates 11 and two second plates 12. The first plates 11 are perpendicular to the first direction L1, and the second plates 12 are perpendicular to the second direction L2. The first and second plates 11, 12 are alternately connected, giving the housing 1 a rectangular parallelepiped shape. The housing 1 has two openings that oppose each other in the third direction L3. There are two cover plates 2, one mounted on each of the openings. The power battery includes two terminals 5, one positive terminal and one negative terminal, mounted on each of the two cover plates 2.

[0039] Furthermore, the surface area of ​​the first plate 11 is smaller than the surface area of ​​the second plate 12 , and the liquid injection hole 4 is provided on the first plate 11 .

[0040] In an embodiment of the present application, as shown in Figures 3 and 4, the power battery further includes a side plate 6, which is arranged inside the shell 1. The side plate 6 divides the interior of the shell 1 into a receiving cavity and a connecting channel. The electrode group 3 is arranged in the receiving cavity, and the connecting channel is connected to the receiving cavity, so that the electrolyte can flow to the receiving cavity through the injection hole 4 and the connecting channel, thereby achieving infiltration of the electrode group 3.

[0041] Further, as shown in Figures 5, 6 and 7, the side panel 6 includes a panel body 61 and a support portion 62. The panel body 61 includes a first plane and a second plane opposite to each other. The first plane and the second plane are both perpendicular to the first direction L1. The support portion 62 is fixed to the first plane, and the support portion 62 abuts against the shell 1. The first plane and the shell 1 enclose a connecting channel, and the second plane and the shell 1 enclose an accommodating cavity. The connecting channel and the accommodating cavity are respectively located on both sides of the panel body 61 in the first direction L1.

[0042] Specifically, the second plate 12 is divided into a first part and a second part by the plate body 61. The two first parts included in the two plate bodies 61, the first first plate 11 and the first plane enclose a connecting channel; the two second parts included in the two side plates 6, the second first plate 11 and the second plane enclose a accommodating cavity.

[0043] Furthermore, the plate body 61 is provided with a plurality of heat dissipation holes 64, which extend through the plate body 61 in a first direction L1. The provision of these heat dissipation holes 64 facilitates the discharge of gases through these holes in the event of thermal runaway. Simultaneously, the connecting channel communicates with the accommodating cavity via the heat dissipation holes 64, allowing electrolyte entering the connecting channel through the injection hole 4 to enter the accommodating cavity through the heat dissipation holes 64, thereby infiltrating the electrode assembly 3 within the accommodating cavity. The orthographic projection of the injection hole 4 on the plate body 61 is located outside the heat dissipation holes 64. That is, no heat dissipation holes 64 are provided at locations on the plate body 61 corresponding to the injection hole 4. This prevents the electrolyte from directly eroding the electrode assembly 3.

[0044] Furthermore, the plate body 61 is provided with guide holes 63 at both ends in the third direction L3. The guide holes 63 penetrate the plate body 61 along the first direction L1, thereby connecting the connecting channel to the accommodating cavity through the guide holes 63. During electrolyte injection, some electrolyte can flow through the injection hole 4, the connecting channel, and the guide holes 63 to the electrode group 3 in the accommodating cavity, thereby achieving infiltration of the electrode group 3.

[0045] Furthermore, the area of ​​the first plane without heat dissipation holes 64 is 20%-80% of the area of ​​the first plane. When the area of ​​the first plane without heat dissipation holes 64 is less than 20% of the area of ​​the first plane, the number of heat dissipation holes 64 on the plate body 61 is large, and the structural strength of the plate body 61 is low. When the area of ​​the first plane without heat dissipation holes 64 is greater than 80% of the area of ​​the first plane, the number of heat dissipation holes 64 on the plate body 61 is small, and gas exhaust in the event of thermal runaway is insufficient. The area of ​​the first plane without heat dissipation holes 64 is 20%-80% of the area of ​​the first plane. This ensures that the number of heat dissipation holes 64 is sufficient to exhaust gas in the event of thermal runaway while maintaining the structural strength of the plate body 61.

[0046] In the embodiment of the present application, the number of the liquid injection holes 4 is one, two or more.

[0047] When there is only one injection hole 4, the distance between the injection hole 4 and both ends of the first plate 11 in the third direction L3 is greater than 1 / 3 of the length L of the first plate 11 in the third direction L3. That is, the two edges of the first plate 11 in the third direction L3 are defined as the first edge and the second edge. The distance X1 between the edge of the injection hole 4 and the first edge is greater than 1 / 3 of the length L of the first plate 11 in the third direction L3, that is, X1>L / 3. The distance X2 between the edge of the injection hole 4 and the second edge is greater than 1 / 3 of the length L of the first plate 11 in the third direction L3, that is, X2>L / 3. In other words, the injection hole 4 is located in the region of the entire first plate 11 between L / 3 and 2L / 3. Placing the injection hole 4 within the aforementioned range places the injection hole 4 in the middle of the first plate 11. The electrolyte injected through the injection hole 4 can enter the accommodating cavity after flowing a shorter distance to infiltrate the electrode assembly 3, further shortening the electrolyte infiltration path.

[0048] When the number of injection holes 4 is greater than or equal to two, the distance between the centers of any two injection holes 4 is greater than or equal to 2 mm, so that the injection holes 4 are evenly distributed on the first plate 11, and the electrolyte can enter the accommodating cavity after flowing a smaller distance to infiltrate the electrode group 3, further shortening the infiltration path of the electrolyte.

[0049] In the embodiment of the present application, the power battery further includes an explosion-proof valve 7, which is disposed on the same first plate 11 as the liquid injection port 4. In the event of thermal runaway in the power battery, gas escapes through the explosion-proof valve 7 on the housing 1. Thus, the circuit connected to the pole 5 is located on the side where the cover plate 2 is located, and the explosion-proof valve 7 is disposed on the first plate 11. This allows the power battery to separate the thermal runaway pressure relief channel from the circuit, thereby improving the safety of the power battery.

[0050] Optionally, the number of explosion-proof valves 7 may be one, two, or more.

[0051] Furthermore, the distance between the edge of the explosion-proof valve 7 and the center of the liquid injection hole 4 in the second direction L2 is greater than or equal to 1 mm. For example, the distance between the edge of the explosion-proof valve 7 and the center of the liquid injection hole 4 in the second direction L2 can be 1 mm, 2 mm, 3 mm, or 5 mm. When there is only one explosion-proof valve 7, the distance between the edge of the explosion-proof valve 7 in the second direction L2 and the center of the liquid injection hole 4 in the second direction is greater than or equal to 1 mm. When there are multiple explosion-proof valves 7, the centers of the multiple explosion-proof valves 7 are collinear, and the distance between the straight line containing the centers of the multiple explosion-proof valves 7 and the center of the liquid injection hole 4 in the second direction is greater than or equal to 1 mm.

[0052] When the power battery of the present application is injected with electrolyte, the electrolyte can start to infiltrate the electrode group 3 from the middle of the electrode group 3. Part of the electrolyte can also flow to the two ends of the accommodating cavity through the connecting channel, and then infiltrate from the two ends of the electrode group 3 to the middle of the electrode group 3. In this way, the infiltration path of the electrolyte is shortened.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application. Industrial Applicability

[0054] The power battery provided herein comprises an electrode assembly disposed within a housing cavity, connecting both ends of a connecting channel to the housing cavity, and providing a liquid injection hole on a side plate that communicates with the connecting channel. During liquid injection, the electrolyte flows through the connecting channel into the housing cavity, and then infiltrates from the center of the electrode assembly toward both ends of the electrode assembly, thereby shortening the electrolyte infiltration path.

Claims

1. A power battery, characterized in that: The power battery includes a shell, a cover plate, a pole group and a liquid injection hole. The shell includes a accommodating cavity and a connecting channel. The cover plate is arranged on the end of the shell, the pole group is arranged inside the accommodating cavity, and the connecting channel is communicated with the accommodating cavity; the liquid injection hole is arranged in the shell, and the liquid injection hole is communicated with the connecting channel; the power battery also includes a side plate, which is arranged inside the shell, and the side plate divides the inside of the shell into the accommodating cavity and the connecting channel.

2. The power battery according to claim 1, characterized in that: The shell includes two first plates and two second plates, the first plates and the second plates are alternately connected, the first plates are perpendicular to the first direction, the second plates are perpendicular to the second direction, and the first direction is perpendicular to the second direction; the surface area of ​​the first plate is smaller than the surface area of ​​the second plate, and the injection hole is arranged on the first plate.

3. The power battery according to claim 2, characterized in that: The number of the injection hole is one, and the distance between the injection hole and two ends of the first plate in the third direction is greater than 1 / 3 of the length of the first plate in the third direction.

4. The power battery according to claim 2, characterized in that: The number of the injection holes is greater than or equal to two, and the distance between the centers of any two of the injection holes is greater than or equal to 2 mm.

5. The power battery according to claim 2, characterized in that: The power battery further includes an explosion-proof valve, which is disposed on the same first plate as the injection hole, and a distance between an edge of the explosion-proof valve and a center of the injection hole in the second direction is greater than or equal to 1 mm.

6. The power battery according to claim 3, characterized in that: The side plate includes a plate body and a supporting portion, the plate body includes a first plane and a second plane opposite to each other, the first plane and the second plane are both perpendicular to the first direction, the supporting portion is fixed to the first plane, and the supporting portion abuts against the shell, the first plane and the shell enclose the connecting channel, and the second plane and the shell enclose the accommodating cavity.

7. The power battery according to claim 6, characterized in that: The plate body is provided with flow guide holes at both ends in the third direction, the flow guide holes penetrate the plate body along the first direction, and the flow guide holes communicate with the accommodating cavity and the connecting channel.

8. The power battery according to claim 6, characterized in that: The plate body is provided with a plurality of heat dissipation holes, the heat dissipation holes penetrate the plate body along the first direction, and the orthographic projection of the injection hole on the plate body is located outside the heat dissipation holes.

9. The power battery according to claim 8, characterized in that: The area of ​​the first plane where the heat dissipation holes are not provided is 20%-80% of the area of ​​the first plane.

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