Cover plate assembly, battery cell and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a cover plate assembly, a battery cell and a battery pack, the cover plate assembly comprises a cover plate body, a sealing member and a first insulating member. Wherein the cover plate body is provided with a positive pole hole and a negative pole hole; the bottom of the positive pole is provided with an abutting part; the first insulating part is arranged on the inner wall surface of the cover plate body, and the abutting part abuts against the inner wall surface of the first insulating part; and a liquid guide hole is formed in the first insulating part between the abutting part and the cover plate body. According to the cover plate assembly with the structure, the liquid guide hole is formed in the first insulating part between the abutting part of the positive pole and the cover plate body, the cover plate assembly is applied to the battery cell, after electrolyte is injected into the shell of the battery cell, the electrolyte enters the liquid guide hole, and the electrolyte in the liquid guide hole conducts the positive pole and the cover plate body, so that the total resistance of the positive pole can be reduced, and the service life of the battery cell is prolonged. The negative electrode side voltage can be effectively improved, the corrosion and liquid leakage phenomena of the battery are prevented, and the battery performance is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a cover plate assembly, a battery cell and a battery pack. Background Art

[0002] After the battery is manufactured, the voltage value between the negative electrode column and the shell is usually measured. This voltage value is the negative electrode side voltage, and the negative electrode side voltage value usually needs to be greater than or equal to 0.3V. When the negative electrode side voltage is lower than 0.3V, battery corrosion and leakage will occur, which will lead to battery failure. The negative electrode side voltage value of the battery cell in the prior art is relatively low. Summary of the invention

[0003] In view of this, the present invention provides a cover plate assembly, a battery cell and a battery pack to solve the problem in the prior art that the negative electrode side voltage of the battery is low, resulting in corrosion and leakage of the battery.

[0004] In a first aspect, the present invention provides a cover plate assembly, comprising:

[0005] A cover body, on which a positive pole column hole and a negative pole column hole are provided, wherein a positive pole column is provided in the positive pole column hole, and a negative pole column is provided in the negative pole column hole; a butt joint is provided at the bottom of the positive pole column, and the butt joint is located on the inner side of the cover body;

[0006] A sealing member, sealed between the positive electrode column and the cover plate body, and sealed between the negative electrode column and the cover plate body;

[0007] The first insulating member is arranged on the inner wall surface of the cover body, and the abutting portion abuts against the inner wall surface of the first insulating member; a liquid guide hole is arranged on the first insulating member between the abutting portion and the cover body.

[0008] Beneficial effect: In the cover plate assembly of this structure, a liquid guide hole is arranged on the first insulating member between the abutting part of the positive electrode column and the cover plate body. The cover plate assembly is used in the battery cell. After the electrolyte is injected into the shell of the battery cell, the electrolyte enters the liquid guide hole. The electrolyte in the liquid guide hole conducts the positive electrode column and the cover plate body. This area is weakly charged and has a certain resistance value. The resistance of this part of the electrolyte is in parallel with the resistance of the positive electrode column. After the resistances are connected in parallel, the total resistance is reduced, thereby reducing the total resistance of the positive electrode, and the voltage U at the negative electrode side is 负 =R 负 / (R 正 +R 负 )*U 总 , where R 正 is the total resistance of the positive electrode, R 负 is the total resistance of the negative electrode, U 总is the total voltage of the battery. The negative electrode voltage is inversely proportional to the total positive electrode resistance. When the total positive electrode resistance is reduced, the negative electrode voltage can be effectively increased to prevent battery corrosion and leakage, thereby ensuring battery performance.

[0009] In an optional embodiment, the opening area of ​​the liquid guide hole is S, 2mm 2 ≤S≤100mm 2 .

[0010] Beneficial effect: This arrangement can ensure that the liquid guide hole has a sufficient opening area, and ensure that the liquid guide hole can enter and be filled with electrolyte, so that the electrolyte conducts the positive electrode column and the cover body; at the same time, S≤100mm 2 This arrangement can prevent the opening of the liquid guide hole from being too large and affecting the insulation effect and strength of the first insulating member.

[0011] In an optional embodiment, a plurality of the liquid conducting holes are provided on the first insulating member, and the plurality of the liquid conducting holes are arranged at intervals.

[0012] Beneficial effect: A plurality of liquid guide holes are provided to ensure that the electrolyte can enter the liquid guide holes and conduct the positive electrode column and the cover body, so as to effectively reduce the resistance value on the positive electrode side, thereby increasing the voltage on the negative electrode side.

[0013] In an optional embodiment, the liquid conducting hole is a circular hole.

[0014] In an optional embodiment, two mounting holes are provided on the first insulating member, and the positive electrode column and the negative electrode column are respectively provided in the two mounting holes; a step portion is protruded from the inner wall of the first insulating member at the outer edge of the mounting hole, and the step portion is arranged outside the mounting hole, and an air intake channel is provided on the step portion, and the air intake channel connects the inside and the outside of the step portion, and the abutting portion abuts against the step portion.

[0015] Beneficial effect: A step portion is provided on the inner wall surface of the first insulating part, and an air inlet channel is provided on the step portion, and the abutting portion abuts against the step portion. When the cover assembly is subjected to an air tightness test, the introduced gas can enter the mounting hole from the air inlet channel and then reach the sealing member, so that it is possible to determine whether there is an air leak at the sealing member based on the test results, so as to accurately detect whether the sealing of the cover assembly meets the requirements.

[0016] In an optional embodiment, a plurality of the air intake channels are provided on the step portion, and the plurality of the air intake channels are arranged at intervals along the circumferential outer edge of the mounting hole.

[0017] Beneficial effect: This arrangement can ensure that during the airtight test, the gas enters the interior of the mounting hole from multiple air inlet channels, thereby ensuring the air intake volume.

[0018] In an optional embodiment, the step portion is located on the circumferential outer side of the hole wall of the mounting hole toward the inner side wall of the mounting hole.

[0019] Beneficial effect: Such a setting is more conducive to the gas entering the mounting hole through the air inlet channel, the part between the abutting part and the plane area during the air tightness test, thereby ensuring the accuracy of the air tightness test.

[0020] In an optional embodiment, a blocking portion is provided on the outer wall of the step portion away from the mounting hole, the thickness of the blocking portion is greater than the thickness of the step portion, the circumferential outer wall of the abutting portion abuts against the inner wall of the blocking portion, and the air intake passage passes through the blocking portion.

[0021] Beneficial effect: The enclosing portion can limit the abutting portion.

[0022] In a second aspect, the present invention provides a battery cell, comprising any one of the above-mentioned cover plate assemblies. The battery cell comprises the cover plate assembly, which has the same technical effect as the cover plate assembly and is not described in detail here.

[0023] In a third aspect, the present invention provides a battery pack, comprising the above-mentioned battery cell. The battery pack includes a cover plate assembly, which has the same technical effect as the cover plate assembly and is not described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of the three-dimensional structure of a cover plate assembly according to an embodiment of the present invention;

[0026] Figure 2 A top view of a cover plate assembly according to an embodiment of the present invention;

[0027] Figure 3 for Figure 2 AA section view;

[0028] Figure 4 for Figure 3 A partial enlarged view of the middle A part;

[0029] Figure 5 is a schematic diagram of the three-dimensional structure of the first insulating member;

[0030] Figure 6 is a top view of the first insulating member;

[0031] Figure 7 is a bottom view of the first insulating member;

[0032] Figure 8 It is a schematic diagram of the three-dimensional structure of a cover plate assembly according to an embodiment of the present invention;

[0033] Fig. 9 for Figure 8 A partial enlarged view of the middle B part;

[0034] Fig.10 Schematic diagram of a battery cell according to an embodiment of the present invention.

[0035] Description of reference numerals:

[0036] 1. Cover plate body; 2. Positive pole; 21. Abutment portion; 3. Negative pole; 4. Sealing member; 5. First insulating member; 51. Liquid guide hole; 52. Mounting hole; 53. Step portion; 54. Air inlet passage; 55. Enclosure portion; 6. Shell. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0038] The cover plate assembly is arranged on the shell 6 of the battery cell, and the side of each component facing the outside of the battery cell is called the outer wall surface, and the side of each component facing the inside of the battery cell is called the inner wall surface.

[0039] Combine the following Figures 1 to 10 , describing an embodiment of the present invention.

[0040] According to an embodiment of the present invention, on one hand, a cover plate assembly is provided, including a cover plate body 1 , a sealing member 4 and a first insulating member 5 .

[0041] Among them, the cover body 1 is provided with a positive column hole and a negative column hole, the positive column hole is provided with a positive column 2, and the negative column hole is provided with a negative column 3; the bottom of the positive column 2 has an abutment portion 21, and the abutment portion 21 is located on the inner side of the cover body 1; the sealing member 4 is sealed between the positive column 2 and the cover body 1, and between the negative column 3 and the cover body 1; the first insulating member 5 is provided on the inner wall surface of the cover body 1, and the abutment portion 21 abuts on the inner wall surface of the first insulating member 5; a liquid guide hole 51 is provided on the first insulating member 5 between the abutment portion 21 and the cover body 1.

[0042] In the cover plate assembly of this structure, a liquid guide hole 51 is provided on the first insulating member 5 between the abutting portion 21 of the positive electrode column 2 and the cover plate body 1. The cover plate assembly is used in the battery cell. After the electrolyte is injected into the shell 6 of the battery cell, the electrolyte enters the liquid guide hole 51. The electrolyte in the liquid guide hole 51 conducts the positive electrode column 2 and the cover plate body 1. This area is weakly charged and has a certain resistance value. The resistance of this part of the electrolyte is in parallel with the resistance of the positive electrode column 2. After the resistances are connected in parallel, the total resistance is reduced, thereby reducing the total resistance of the positive electrode, and the negative electrode side voltage U 负 =R 负 / (R 正 +R 负 )*U 总 , where R 正 is the total resistance of the positive electrode, R 负 is the total resistance of the negative electrode, U 总 is the total voltage of the battery. The negative electrode voltage is inversely proportional to the total positive electrode resistance. When the total positive electrode resistance is reduced, the negative electrode voltage can be effectively increased to prevent battery corrosion and leakage, thereby ensuring battery performance.

[0043] Three groups of cover plate assemblies were made. Liquid guide holes 51 were provided on the first insulating members 5 of the three groups of cover plate assemblies. The positive pole 2 and the negative pole 3 of the cover plate assemblies were connected to a power supply (3.3 V voltage). The first insulating member 5 of the cover plate assemblies was set upward. A certain amount of electrolyte was dripped into the positive pole 2 and the negative pole 3 regions. The negative pole side voltage and the positive pole side voltage of the three groups of cover plate assemblies were measured. The test results are shown in Table 1.

[0044] Table 1 Measurement results of positive and negative side voltages of cover plate assembly

[0045] Positive side voltage / V Negative side voltage / V Cover assembly 1 0.05 3.30 Cover assembly 2 0.01 3.30 Cover assembly 3 0.2 3.1

[0046] It can be seen from Table 1 that after the liquid guide hole 51 is set on the first insulating member 5 on the positive electrode column 2 side, after the electrolyte is dripped into the positive electrode column 2 and the negative electrode column 3, the negative electrode side voltage is 3.1V or 3.3V, and the negative electrode side voltage is much larger than 0.3V. The cover assembly of the new structure effectively increases the negative electrode side voltage and can reduce the risk of battery corrosion failure.

[0047] Optionally, in some embodiments, the opening area of ​​the liquid guide hole 51 is S, 2 mm 2 ≤S≤100mm 2 This arrangement can ensure that the liquid guide hole 51 has a sufficient opening area, and ensure that the electrolyte can enter and fill the liquid guide hole 51, so that the electrolyte conducts the positive electrode column 2 and the cover body 1; at the same time, S≤100mm 2 This arrangement can prevent the opening of the liquid guide hole 51 from being too large and affecting the insulation effect and strength of the first insulating member 5.

[0048] In some embodiments, Figures 5 to 7 As shown, the first insulating member 5 is provided with a plurality of liquid guide holes 51, and the plurality of liquid guide holes 51 are arranged at intervals. There are a plurality of liquid guide holes 51 to ensure that the electrolyte can enter the liquid guide holes 51 and conduct the positive electrode column 2 and the cover body 1, so as to effectively reduce the resistance value on the positive electrode side, thereby increasing the voltage on the negative electrode side.

[0049] Optionally, in some embodiments, the liquid conducting hole 51 is a circular hole, which facilitates the formation of the liquid conducting hole 51 .

[0050] In some embodiments, Figures 5 to 7 As shown, the first insulating member 5 is provided with two mounting holes 52, and the positive pole 2 and the negative pole 3 are respectively provided in the two mounting holes 52; the inner wall of the first insulating member 5 at the outer edge of the mounting hole 52 is protruded with a step portion 53, and the step portion 53 is arranged outside the mounting hole 52, and an air inlet passage 54 is provided on the step portion 53, and the air inlet passage 54 communicates the inside and the outside of the step portion 53, and the abutting portion 21 abuts on the step portion 53. If the step portion 53 is not provided, the abutting portion 21 directly abuts on the inner wall surface of the first insulating member 5. When the sealing performance of the cover plate assembly is tested, the cover plate assembly is placed in a closed space, and gas is introduced into the cover plate assembly from one side of the inner wall surface of the first insulating member 5. The abutting portion 21 directly abuts on the inner wall surface of the first insulating member 5, which will block the passage of gas entering the mounting hole 52, thereby making it difficult for the gas to reach the sealing member 4, and it is impossible to judge whether the sealing performance of the sealing member 4 meets the requirements. In the present invention, a step portion 53 is provided on the inner wall surface of the first insulating part 5, and an air inlet channel 54 is provided on the step portion 53, and the abutting portion 21 abuts against the step portion 53. When the air tightness test of the cover assembly is performed, the introduced gas can enter the mounting hole 52 from the air inlet channel 54 and then reach the sealing member 4, so that it can be judged whether there is air leakage at the sealing member 4 based on the test results, so as to accurately detect whether the sealing of the cover assembly meets the requirements.

[0051] Optionally, in some embodiments, a plurality of air inlet channels 54 are provided on the step portion 53, and the plurality of air inlet channels 54 are arranged at intervals along the circumferential outer edge of the mounting hole 52. Such an arrangement can ensure that during the airtight test, the gas enters the interior of the mounting hole 52 from the plurality of air inlet channels 54, thereby ensuring the air intake volume.

[0052] In some embodiments, Figure 7 As shown, the step portion 53 is located on the circumferential outside of the hole wall of the mounting hole 52 toward the inner wall of the mounting hole 52, so that the plane area of ​​the inner wall surface of the first insulating member 5 is exposed between the inner wall of the step portion 53 and the hole wall of the mounting hole 52, and the abutment portion 21 abuts against the step portion 53. The abutment portion 21 is spaced apart from the plane area, which is more conducive to the gas entering the mounting hole 52 through the air inlet channel 54 and the portion between the abutment portion 21 and the plane area during the air-tightness test, thereby ensuring the accuracy of the air-tightness test.

[0053] like Figure 7 As shown, the inner wall of the step portion 53 is circular, the mounting hole 52 is a circular hole, the inner wall of the step portion 53 is cocentric with the mounting hole 52 , and the diameter of the inner wall of the mounting hole 52 is greater than the diameter of the mounting hole 52 .

[0054] Optionally, four air inlet passages 54 are provided on the step portion 53 , and the four air inlet passages 54 are arranged at equal intervals along the circumference of the inner side wall of the step portion 53 .

[0055] like Figures 7 to 9 As shown, in some embodiments, a blocking portion 55 is provided on the outer wall of the step portion 53 away from the mounting hole 52, and the thickness of the blocking portion 55 is greater than the thickness of the step portion 53, that is, the inner wall surface of the blocking portion 55 protrudes inwardly from the inner wall surface of the step portion 53, and the circumferential outer wall of the abutting portion 21 abuts against the inner wall of the blocking portion 55, and the air intake passage 54 is arranged through the blocking portion 55, so that the blocking portion 55 limits the abutting portion 21.

[0056] In some embodiments, the outer wall of the step edge is rectangular, with arc structures and bevel structures set at its four corners. The enclosure 55 is arranged outside the step portion 53, and the outer peripheral wall of the abutment portion 21 abuts against the inner wall of the enclosure 55, which can limit the pole circumferentially to prevent the pole from rotating.

[0057] Step portions 53 and blocking portions 55 are provided on the inner wall surfaces of the two mounting holes 52 of the first insulating member 5 .

[0058] In some embodiments, the cover assembly further includes a second insulating member and a rivet block, the second insulating member is disposed on the outer wall surface of the cover body 1, and the rivet block is disposed on the outer wall surface of the second insulating member.

[0059] Optionally, in some embodiments, the cover body 1 includes a plain aluminum sheet, the first insulating member 5 includes an upper plastic, and the second insulating member includes a lower plastic.

[0060] According to an embodiment of the present invention, on the other hand, a battery cell is also provided, such as Fig.10 As shown, it includes the above-mentioned cover plate assembly and a shell 6, and the cover plate assembly is arranged on the top opening of the shell 6.

[0061] In the battery cell of this structure, a liquid conducting hole 51 is provided on the first insulating member 5 between the abutting portion 21 of the positive electrode column 2 and the cover body 1. The electrolyte in the liquid conducting hole 51 conducts the positive electrode column 2 and the cover body 1, thereby reducing the total resistance of the positive electrode. The negative electrode side voltage is inversely proportional to the positive electrode resistance. After the total positive electrode resistance is reduced, the negative electrode side voltage can be effectively increased to prevent corrosion and leakage of the battery cell, thereby ensuring the battery cell performance.

[0062] According to an embodiment of the present invention, on the other hand, a battery pack is provided, comprising the above-mentioned battery cell.

[0063] In the battery pack of this structure, the first insulating member 5 on the battery cell therein is provided with a liquid guide hole 51 on the first insulating member 5 between the abutting portion 21 of the positive electrode column 2 and the cover body 1, thereby reducing the total resistance of the positive electrode, effectively increasing the voltage at the negative electrode side, and preventing corrosion and leakage of the battery cell, thereby ensuring the performance of the battery cell and the battery pack.

[0064] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A cover plate assembly, characterized in that: include: A cover body, on which a positive pole column hole and a negative pole column hole are provided, wherein a positive pole column is provided in the positive pole column hole, and a negative pole column is provided in the negative pole column hole; a butt joint is provided at the bottom of the positive pole column, and the butt joint is located on the inner side of the cover body; A sealing member, sealed between the positive electrode column and the cover plate body, and sealed between the negative electrode column and the cover plate body; The first insulating member is arranged on the inner wall surface of the cover body, and the abutting portion abuts against the inner wall surface of the first insulating member; a liquid guide hole is arranged on the first insulating member between the abutting portion and the cover body.

2. The cover plate assembly according to claim 1, characterized in that: The opening area of ​​the liquid guide hole is S, 2mm 2 ≤S≤100mm 2 .

3. The cover plate assembly according to claim 1 or 2, characterized in that: The first insulating member is provided with a plurality of liquid guiding holes, and the plurality of liquid guiding holes are arranged at intervals.

4. The cover plate assembly according to claim 1 or 2, characterized in that: The liquid guiding hole is a circular hole.

5. The cover plate assembly according to claim 1 or 2, characterized in that: The first insulating member is provided with two mounting holes, and the positive electrode column and the negative electrode column are respectively arranged in the two mounting holes; the inner wall of the first insulating member at the outer edge of the mounting hole is protruded with a step portion, and the step portion is arranged outside the mounting hole. The step portion is provided with an air intake channel, and the air intake channel connects the inside and the outside of the step portion, and the abutting portion abuts against the step portion.

6. The cover plate assembly according to claim 5, characterized in that: A plurality of the air inlet passages are provided on the step portion, and the plurality of the air inlet passages are arranged at intervals along the circumferential outer edge of the mounting hole.

7. The cover plate assembly according to claim 5, characterized in that: The step portion is located on the circumferential outer side of the hole wall of the mounting hole toward the inner side wall of the mounting hole.

8. The cover plate assembly according to claim 5, characterized in that: A blocking portion is provided on the outer side wall of the step portion away from the mounting hole, the thickness of the blocking portion is greater than the thickness of the step portion, the circumferential outer side wall of the abutting portion abuts against the inner side wall of the blocking portion, and the air intake passage passes through the blocking portion.

9. A battery cell, characterized in that: A cover plate assembly comprising any one of claims 1 to 8.

10. A battery pack, characterized in that: Comprising the battery cell as claimed in claim 9.

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