A lower plastic structure and a top cover assembly

Abstract

The utility model provides a kind of lower plastic structure and top cover assembly, it is related to battery field, and the lower plastic structure in it includes lower plastic body and flow guide assembly;Lower plastic body is equipped with overflow hole of intercommunication top cover liquid injection hole;Flow guide assembly includes first flow guide piece, stop plate and pillar, first flow guide piece is equipped with flow guide channel, one end of first flow guide piece is connected with lower plastic body, and flow guide channel is connected by overflow hole;Stop plate is below the other end of first flow guide piece, and with the axis direction of overflow hole perpendicular;The both ends of pillar are connected first flow guide piece end face and stop plate respectively, to make that first flow guide piece and stop plate between there is gap. Through flow guide channel, electrolyte guided into from overflow hole is directed to stop plate, and electrolyte is discharged from the gap between first flow guide piece and stop plate after the buffering of stop plate, so that the kinetic energy of electrolyte is greatly reduced, and the impact force of electrolyte is greatly reduced.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a lower plastic structure and a top cover assembly. Background Technology

[0002] As the capacity of power and energy storage cells increases significantly, the electrolyte injection volume also increases dramatically, significantly extending the electrolyte injection time. This prolonged high-pressure electrolyte flow impact causes numerous adverse effects on the internal winding of the casing: such as the winding gaps being broken open, material loss or film detachment at the outer negative electrode edge, and the rupture of the weakly bound separator. Excessive winding gaps severely hinder lithium intercalation at the electrode edges, causing interface defects such as black and purple spots. Material loss at the negative electrode edge can also cause conductivity issues between the positive and negative electrodes, resulting in severe self-discharge abnormalities in the cell. Furthermore, during long-term cycling, localized material loss or film detachment causes repeated lithium intercalation and deintercalation contraction and expansion of the negative electrode, leading to uneven stress distribution near the detached area, further increasing the detached area, resulting in greater loss of active material and a significant drop in capacity. In addition, negative electrode film detachment causes insufficient or missing material in certain areas, which in severe cases can lead to safety risks such as interface lithium plating and piercing of the separator.

[0003] In the existing technology, because the electrolyte is injected through a single hole, the impact force of the electrolyte is relatively large and the injection time is relatively long, which can easily lead to the above-mentioned potential risks, and a proper solution is urgently needed. Utility Model Content

[0004] In view of this, the present invention proposes a lower plastic structure and a top cover assembly to solve the technical problems mentioned in the background art, such as the core gap being broken open, the outer negative electrode edge losing material or the film layer falling off, and the weakly bound diaphragm being broken due to the large impact force of the electrolyte.

[0005] The technical solution of this utility model is implemented as follows:

[0006] In a first aspect, this utility model provides a lower plastic structure, including a lower plastic body and a flow guiding component, wherein:

[0007] The lower plastic body is provided with a flow hole that connects to the liquid injection hole of the top cover;

[0008] The flow guiding assembly includes a first flow guiding member, a stop plate, and a support column. The first flow guiding member has a flow guiding channel, and one end of the first flow guiding member is connected to the lower plastic body. The flow guiding channel is connected to the flow hole. The stop plate is located below the other end of the first flow guiding member and is perpendicular to the axial direction of the flow hole. The two ends of the support column are respectively connected to the end face of the first flow guiding member and the stop plate, so that there is a gap between the first flow guiding member and the stop plate.

[0009] Based on the above technical solutions, preferably, the first guide element is a hollow cone, the diameter of the guide channel gradually increases, and the diameter of the end of the guide channel connected to the flow hole is the smallest and greater than or equal to the diameter of the flow hole.

[0010] Based on the above technical solutions, preferably, the flow guiding assembly further includes a second flow guiding component, the second flow guiding component includes a connecting ring and a flow guiding plate, the connecting ring is connected to the side of the stop plate away from the support column, the inner diameter of the connecting ring is smaller than the outer diameter of the stop plate; the flow guiding plate is connected to the end of the connecting ring away from the stop plate, and extends outward in a direction away from the first flow guiding component.

[0011] Based on the above technical solutions, preferably, the guide plate is inclined and the cross-section of the guide plate is a hollow frustum.

[0012] Based on the above technical solutions, preferably, the angle between the inclined surface of the guide plate in the cross section and the plane where the connecting ring is located is 3~15°.

[0013] Based on the above technical solutions, preferably, the guide plate is provided with multiple rings of first guide holes and multiple rings of second guide holes along the circumference, the axis of the first guide hole is parallel to the axis of the connecting ring, and the axis of the second guide hole intersects with the axis of the first guide hole.

[0014] Based on the above technical solutions, preferably, the angle between the axis of the second guide hole and the plane where the connecting ring is located is 45~60°.

[0015] Based on the above technical solutions, preferably, the diameter of the second guide hole is the same as the diameter of the first guide hole.

[0016] Based on the above technical solutions, preferably, the lower plastic body has a reinforcing protrusion at the position corresponding to the explosion-proof valve of the battery cell, and the reinforcing protrusion has a vent hole.

[0017] Secondly, the present invention provides a top cover assembly, including a top cover and a lower plastic structure as described in the first aspect. The top cover is connected to the lower plastic body. The top cover is provided with an injection hole communicating with the flow hole. The top cover is provided with a positive electrode post and a negative electrode post. The lower plastic body is provided with a positive electrode through hole corresponding to the positive electrode post and a negative electrode through hole corresponding to the negative electrode post.

[0018] The lower plastic structure and top cover assembly of this utility model have the following advantages over the prior art:

[0019] (1) The electrolyte introduced from the flow hole through the flow channel is guided to the baffle. After being buffered by the baffle, the electrolyte flows out from the gap between the first flow guide and the baffle, which greatly reduces the kinetic energy of the electrolyte and greatly reduces the impact force of the electrolyte, preventing problems such as the core gap being broken, the outer negative electrode edge falling off or the membrane layer falling off and the weakly bound diaphragm being broken due to excessive impact force.

[0020] (2) The diameter of the flow channel gradually increases, and the diameter of the end of the flow channel connected to the flow hole is the smallest and greater than or equal to the diameter of the flow hole. This can completely wrap the flow hole, avoid the phenomenon of electrolyte overflowing due to the electrolyte not being able to enter the cell in time during liquid injection, and improve reliability.

[0021] (3) The connecting ring is connected to the side of the stop plate away from the support column. The inner diameter of the connecting ring is smaller than the outer diameter of the stop plate. The guide plate is connected to the end of the connecting ring away from the stop plate and extends outward in a direction away from the first guide member. After the electrolyte flows through the guide plate, the kinetic energy is further reduced, which can further reduce the impact force of the electrolyte.

[0022] (4) The angle between the inclined surface in the cross section of the guide plate and the plane where the connecting ring is located is 3~15°. A small inclination angle helps the injected electrolyte to be dispersed around the battery cell, and a small inclination angle can reduce the margin in terms of the lower plastic height, thus avoiding the reduction of the battery cell energy density due to the presence of the guide plate.

[0023] (5) The guide plate is provided with multiple first guide holes and multiple second guide holes in the circumferential direction. The axis of the first guide hole is parallel to the axis of the connecting ring, and the axis of the second guide hole intersects with the axis of the first guide hole. When the electrolyte flows through the first guide hole and the second guide hole, the kinetic energy will be reduced again and dispersed in various directions. By reducing the kinetic energy of the high voltage electrolyte and the electrolyte dispersion injection method, the impact force on the core is reduced, and the wetting effect of the core can be improved. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the lower plastic structure in an embodiment of the present utility model;

[0026] Figure 2 This is an exploded view of the lower plastic structure in an embodiment of this utility model;

[0027] Figure 3 This is a schematic diagram of the flow guiding component in an embodiment of the present utility model;

[0028] Figure 4 This is a schematic diagram of the structure of the first flow guide, the stop plate, and the support column in this embodiment of the present utility model;

[0029] Figure 5 This is a schematic diagram of the structure of the second flow guide in an embodiment of the present utility model;

[0030] Figure 6 This is a schematic diagram of the top cover assembly in an embodiment of the present utility model;

[0031] Figure 7 This is an exploded view of the top cover assembly in an embodiment of this utility model.

[0032] Explanation of reference numerals in the attached diagram: 1-Lower plastic body, 2-Flow guiding component;

[0033] 100-Top cover, 101-Injection hole, 102-Positive electrode post, 103-Negative electrode post;

[0034] 11-Flow passage, 12-Reinforcing protrusion, 121-Ventilation hole, 13-Positive electrode through hole, 14-Negative electrode through hole;

[0035] 21-First guide component, 211-Guide channel, 22-Stop plate, 23-Support column, 24-Second guide component, 241-Connecting ring, 242-Guide plate, 2421-First guide hole, 2422-Second guide hole, 243-Bottom edge. Detailed Implementation

[0036] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0037] Reference Figures 1-7 As shown, in a first aspect embodiment of the present invention, a lower plastic structure is provided, comprising a lower plastic body 1 and a flow guiding component 2, wherein:

[0038] The lower plastic body 1 is provided with a flow hole 11 that connects to the liquid injection hole 101 of the top cover 100; after the lower plastic body 1 is connected to the top cover 100, the flow hole 11 connects to the liquid injection hole 101.

[0039] The flow guiding assembly 2 includes a first flow guiding member 21, a stop plate 22, and a support column 23. The first flow guiding member 21 has a flow guiding channel 211, one end of which is connected to the lower plastic body 1, and the flow guiding channel 211 connects to the flow hole 11. The stop plate 22 is located below the other end of the first flow guiding member 21 and is perpendicular to the axial direction of the flow hole 11. The two ends of the support column 23 are respectively connected to the end face of the first flow guiding member 21 and the stop plate 22, so that there is a gap between the first flow guiding member 21 and the stop plate 22. The stop plate 22 is a circular flat plate, and the diameter of the stop plate 22 needs to be larger than the diameter of the injection hole 101 to avoid affecting the injection speed of the battery cell.

[0040] The lower plastic structure proposed in this embodiment guides the electrolyte introduced from the flow hole 11 to the stop plate 22 through the flow channel 211. After being buffered by the stop plate 22, the electrolyte flows out from the gap between the first flow guide 21 and the stop plate 22, which greatly reduces the kinetic energy of the electrolyte and significantly reduces the impact force of the electrolyte. This prevents problems such as the core gap being broken, the outer negative electrode edge losing material or the film layer falling off, and the weakly bound diaphragm being broken due to excessive impact force.

[0041] In some embodiments, the first flow guide 21 is a hollow frustum, and the flow guide channel 211 is a tapered hole penetrating the first flow guide 21. The diameter of the flow guide channel 211 gradually increases, and the diameter of the end of the flow guide channel 211 connected to the flow hole 11 is the smallest and greater than or equal to the diameter of the flow hole 11. The gradually increasing diameter of the flow guide channel 211 provides a pressure relief effect for the electrolyte; the diameter of the end of the flow guide channel 211 connected to the flow hole 11 is greater than or equal to the diameter of the flow hole 11, which completely encloses the flow hole 11, preventing electrolyte overflow during injection due to insufficient electrolyte entry into the cell, thus improving reliability.

[0042] In some embodiments, the flow guiding assembly 2 further includes a second flow guiding member 24, which includes a connecting ring 241 and a flow guiding plate 242. The connecting ring 241 is connected to the side of the stop plate 22 away from the support column 23, and the inner diameter of the connecting ring 241 is smaller than the outer diameter of the stop plate 22. The flow guiding plate 242 is connected to the end of the connecting ring 241 away from the stop plate 22 and extends outward in a direction away from the first flow guiding member 21. Because the flow guiding plate 242 extends outward in a direction away from the first flow guiding member 21, the kinetic energy of the electrolyte decreases further after flowing through the flow guiding plate 242, which can further reduce the impact force of the electrolyte.

[0043] In some embodiments, the guide plate 242 is inclined, and its cross-section is a hollow frustum. The inclined arrangement of the guide plate 242 ensures that all injected electrolyte enters the battery cell, preventing electrolyte residue on the stop plate 22 and improving electrolyte utilization. The second guide member 24 also includes a bottom edge 243, which is connected to the end of the guide plate 242 away from the connecting ring 241. The bottom edge 243 is a ring plate, and its inner edge connects to the guide plate 242, thereby increasing the strength of the lower edge of the guide plate 242.

[0044] In some embodiments, the angle between the inclined surface of the cross-section of the guide plate 242 and the plane containing the connecting ring 241 is 3 to 15°. This angle setting helps the injected electrolyte to disperse around the battery cell and reduces the group margin in the height of the lower plastic component. A smaller group margin means less space is occupied by the lower plastic component in the height direction, thus preventing a decrease in the battery cell's energy density due to the presence of the guide plate 242.

[0045] In some embodiments, the guide plate 242 is provided with multiple turns of first guide holes 2421 and multiple turns of second guide holes 2422 along the circumferential direction. The axis of the first guide holes 2421 is parallel to the axis of the connecting ring 241, and the axis of the second guide holes 2422 intersects the axis of the first guide holes 2421. When the electrolyte flows through the first guide holes 2421 and the second guide holes 2422, its kinetic energy is reduced again and dispersed in various directions. By reducing the kinetic energy of the high-voltage electrolyte and the electrolyte dispersion injection method, the impact force on the core is reduced, and the wetting effect of the core can be improved.

[0046] In some embodiments, the angle between the axis of the second guide hole 2422 and the plane containing the connecting ring 241 is 45° to 60°. This angle setting helps the second guide hole 2422 to disperse the injected electrolyte around the battery cell, improving the wetting effect of the core.

[0047] In some embodiments, the diameter of the second guide hole 2422 is the same as the diameter of the first guide hole 2421. By having the same diameter, the flow rate of each first guide hole 2421 and second guide hole 2422 is the same, resulting in more uniform electrolyte injection and further improving the wetting effect of the core.

[0048] In some embodiments, a reinforcing protrusion 12 is provided on the lower plastic body 1 at the position corresponding to the explosion-proof valve of the battery cell, and the reinforcing protrusion 12 is provided with a vent hole 121. The reinforcing protrusion 12 is located in the middle of the lower plastic body 1, corresponding to the position of the explosion-proof valve, which can increase the overall strength of the lower plastic structure, and the vent hole 121 facilitates the passage of gas generated by the battery cell, ensuring the function of the explosion-proof valve.

[0049] The working principle of the lower plastic structure in this embodiment of the utility model is as follows: the electrolyte introduced from the flow hole 11 is guided to the stop plate 22 through the flow channel 211. After being buffered by the stop plate 22, the electrolyte flows out from the gap between the first flow guide 21 and the stop plate 22, which greatly reduces the kinetic energy of the electrolyte and significantly reduces the impact force of the electrolyte. This prevents problems such as the core gap being broken open, the outer negative electrode edge losing material or the film layer falling off, and the weakly bound diaphragm being broken due to excessive impact force. After flowing out from the gap, the electrolyte flows through the flow guide plate 242, and the kinetic energy is further reduced, which can further reduce the impact force of the electrolyte. When the electrolyte flows through the first flow guide hole 2421 and the second flow guide hole 2422, the kinetic energy will be reduced again and will be dispersed in various directions. By reducing the kinetic energy of the high-voltage electrolyte and the electrolyte dispersion injection method, the impact force on the core is reduced, and the wetting effect of the core can be improved.

[0050] Based on the same concept, the second aspect of the present invention, combined with... Figure 6 and Figure 7 As shown, a top cover assembly is provided, including a top cover 100 and a lower plastic structure as described in the first aspect embodiment. The top cover 100 is connected to the lower plastic body 1. The top cover 100 has an injection hole 101 communicating with the flow hole 11. The top cover 100 has a positive electrode post 102 and a negative electrode post 103. The lower plastic body 1 has a positive electrode through hole 13 corresponding to the positive electrode post 102 and a negative electrode through hole 14 corresponding to the negative electrode post 103. The positive electrode of the battery cell passes through the positive electrode through hole 13 and is connected to the positive electrode post 102, and the negative electrode of the battery cell passes through the negative electrode through hole 14 and is connected to the negative electrode post 103.

[0051] In the top cover assembly proposed in this embodiment, after the electrolyte is buffered by the stop plate 22, it flows out from the gap between the first guide member 21 and the stop plate 22, which greatly reduces the kinetic energy of the electrolyte and significantly reduces the impact force of the electrolyte. This prevents problems such as the core gap being broken open, material falling off the outer negative electrode edge, or the membrane layer falling off and the weakly bound diaphragm being broken due to excessive impact force.

[0052] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A lower plastic structure, characterized in that, Includes a lower plastic body (1) and a flow guiding assembly (2), wherein: The lower plastic body (1) is provided with a flow hole (11) that connects to the liquid injection hole (101) of the top cover (100). The flow guiding assembly (2) includes a first flow guiding member (21), a stop plate (22), and a support column (23). The first flow guiding member (21) is provided with a flow guiding channel (211). One end of the first flow guiding member (21) is connected to the lower plastic body (1), and the flow guiding channel (211) is connected to the flow hole (11). The stop plate (22) is located below the other end of the first flow guiding member (21) and is perpendicular to the axial direction of the flow hole (11). The two ends of the support column (23) are respectively connected to the end face of the first flow guiding member (21) and the stop plate (22) so that there is a gap between the first flow guiding member (21) and the stop plate (22).

2. The lower plastic structure as described in claim 1, characterized in that, The first guide element (21) is a hollow cone. The diameter of the guide channel (211) gradually increases. The diameter of the end of the guide channel (211) connected to the flow hole (11) is the smallest and is greater than or equal to the diameter of the flow hole (11).

3. The lower plastic structure as described in claim 2, characterized in that, The flow guiding assembly (2) further includes a second flow guiding member (24), which includes a connecting ring (241) and a flow guiding plate (242). The connecting ring (241) is connected to the side of the stop plate (22) away from the support column (23). The inner diameter of the connecting ring (241) is smaller than the outer diameter of the stop plate (22). The flow guiding plate (242) is connected to the end of the connecting ring (241) away from the stop plate (22) and extends outward in a direction away from the first flow guiding member (21).

4. The lower plastic structure as described in claim 3, characterized in that, The guide plate (242) is inclined and the cross section of the guide plate (242) is a hollow frustum.

5. The lower plastic structure as described in claim 4, characterized in that, The angle between the inclined surface of the cross section of the guide plate (242) and the plane where the connecting ring (241) is located is 3~15°.

6. The lower plastic structure as described in claim 3, characterized in that, The guide plate (242) is provided with multiple first guide holes (2421) and multiple second guide holes (2422) along the circumferential direction. The axis of the first guide hole (2421) is parallel to the axis of the connecting ring (241), and the axis of the second guide hole (2422) intersects the axis of the first guide hole (2421).

7. The lower plastic structure as described in claim 6, characterized in that, The angle between the axis of the second guide hole (2422) and the plane where the connecting ring (241) is located is 45~60°.

8. The lower plastic structure as described in claim 7, characterized in that, The diameter of the second guide hole (2422) is the same as the diameter of the first guide hole (2421).

9. The lower plastic structure as described in claim 1, characterized in that, The lower plastic body (1) is provided with a reinforcing protrusion (12) at the position corresponding to the explosion-proof valve of the battery cell, and the reinforcing protrusion (12) is provided with a vent hole (121).

10. A top cover assembly, characterized in that, The device includes a top cover (100) and a lower plastic structure as described in any one of claims 1-9. The top cover (100) is connected to the lower plastic body (1). The top cover (100) is provided with an injection hole (101) that connects to the flow hole (11). The top cover (100) is provided with a positive electrode post (102) and a negative electrode post (103). The lower plastic body (1) is provided with a positive electrode through hole (13) corresponding to the positive electrode post (102) and a negative electrode through hole (14) corresponding to the negative electrode post (103).

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