Secondary battery

Abstract

The invention relates to the technical field of batteries, in particular to a secondary battery. The secondary battery comprises: a cover plate, wherein a liquid injection hole is formed in the cover plate; the battery cell is arranged below the cover plate, and a tab is arranged on the battery cell; the lower plastic is arranged between the cover plate and the battery cell, and a liquid guide channel is formed in the position, corresponding to the liquid injection hole, of the lower plastic; the liquid guide channel comprises a first cavity and a second cavity; the first cavity faces the cover plate, the second cavity deviates from the cover plate, and the second cavity is arranged opposite to the tab; the secondary battery also includes a separator having a plurality of through holes; and the separator is arranged between the first cavity and the second cavity. According to the secondary battery disclosed by the invention, the separator is arranged between the first cavity and the second cavity, so that the tab is not easy to be attached to the separator, the electrolyte injection channel can be prevented from being blocked by attachment of the tab and the separator, and meanwhile, the tab or the battery cell can be prevented from being damaged by impact of electrolyte.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a secondary battery. Background Art

[0002] Secondary batteries have the advantages of high power density, high energy density, long storage time, and many cycles. They have broad application prospects in electric transportation vehicles such as electric bicycles and electric vehicles, and large and medium-sized electric equipment such as energy storage facilities.

[0003] During the preparation of the secondary battery, electrolyte needs to be injected into the shell, and the lower plastic needs to be provided with a through hole opposite to the injection hole of the top cover to achieve the injection of the secondary battery. However, due to the structural design requirements and the limited space of the top cover, some rechargeable batteries can only set the injection hole relatively on the upper side of the battery cell's pole ear; at the same time, in order to increase the energy density, the internal space of the secondary battery needs to be arranged very compactly. Therefore, the pole ear of the battery cell is likely to block the through hole of the lower plastic opposite to the injection hole, resulting in the inability to evacuate the interior of the secondary battery during the negative pressure exhaust process.

[0004] CN207038571U provides a secondary battery, in which a convex bulge with a cavity is arranged on an insulating frame, the convex bulge is located below the injection hole of the top cover sheet, and the convex bulge forms a first channel connected to the cavity. During the injection process, the first channel is easily blocked by the pole ear. The secondary battery forms a second channel connected to the cavity through the side of the convex bulge, and even if the pole ear blocks the first channel, liquid injection or air extraction can be performed through the second channel.

[0005] However, the first channel, the second channel and the cavity of the secondary battery form a structure with a large internal cavity and a small channel outlet. During the injection process, since the first channel of the structure is close to the lower tab, the tab is very easy to fit with the convex bump, thereby blocking the first channel. In addition, during the exhaust process, some burrs of the tab may extend into the second channel and electrically connect with the top cover, increasing the risk of short circuit in the battery.

[0006] Therefore, how to provide a secondary battery that can prevent the injection channel from being blocked by the lower tab, while preventing the burrs of the tab from entering the injection channel and electrically connecting with the top cover, thereby reducing the risk of short circuit, has become a technical problem that urgently needs to be solved. Summary of the invention

[0007] The purpose of the present invention is to overcome the problem of existing secondary batteries that the injection channel is easily blocked by the lower pole ear during the injection process, resulting in the inability to inject liquid, and the burrs of the pole ear are easily introduced into the injection channel and electrically connected with the top cover, resulting in a short circuit in the battery. A secondary battery is provided, which can prevent the injection channel from being blocked by the lower pole ear during the injection process, and at the same time prevent the burrs of the pole ear from entering the injection channel and electrically connecting with the top cover, thereby reducing the risk of short circuit.

[0008] In order to achieve the above-mentioned object, the present invention provides a secondary battery, the secondary battery comprising: a cover plate, the cover plate is provided with a liquid injection hole; a battery cell is arranged below the cover plate, and the battery cell is provided with a pole ear; a lower plastic is arranged between the cover plate and the battery cell, and the lower plastic is provided with a liquid guide channel at the position corresponding to the liquid injection hole; an explosion-proof component is fixedly connected to the cover plate through the explosion-proof hole; a positive terminal assembly is fixedly connected to the cover plate through the positive terminal lead-out hole; a negative terminal assembly is fixedly connected to the cover plate through the negative terminal lead-out hole; a shell is provided with a accommodating cavity, the battery cell is in the accommodating cavity, and the cover plate and the lower plastic block the accommodating cavity of the shell; the liquid guide channel comprises a first cavity and a second cavity; the first cavity faces the cover plate, the second cavity faces away from the cover plate, and the second cavity is arranged opposite to the pole ear; the secondary battery also comprises a separator, the separator has a plurality of through holes; the separator is arranged between the first cavity and the second cavity.

[0009] The aperture of the liquid conducting channel of the secondary battery of the present invention close to the tab is large. Compared with the prior art structure in which the liquid injection channel and the liquid injection cavity form a large internal cavity and a small channel outlet, the tab is not easy to block the liquid conducting channel with a large aperture.

[0010] The secondary battery of the present invention forms a first cavity and a second cavity in a liquid guiding channel, and a partition is arranged between the first cavity and the second cavity. The second cavity is arranged opposite to the pole ear, so that there is a certain distance between the partition and the pole ear below the liquid guiding channel, so that the pole ear is not easy to block the through hole of the partition, thereby avoiding the burrs of the pole ear from being electrically connected to the top cover, causing a short circuit in the battery.

[0011] Preferably, the second cavity includes a side wall, the side wall includes a first wall body and a second wall body, and the first wall body and the second wall body form a step surface.

[0012] Preferably, the second cavity comprises a side wall, and the thickness of the side wall at one end close to the partition is greater than the thickness of the side wall at one end close to the tab.

[0013] Preferably, the second cavity comprises a side wall, and the bottom surface of the side wall is configured as a convex tooth surface formed by an arc-shaped protrusion or a concave tooth surface formed by an arc-shaped groove.

[0014] Preferably, the through hole includes a first through hole and a second through hole.

[0015] Preferably, the first through hole is coaxially arranged with the liquid guiding channel and the liquid injection hole.

[0016] More preferably, there are a plurality of second through holes which are evenly distributed around the first through hole at equal angle intervals.

[0017] Preferably, the liquid guiding channel protrudes downward from the lower plastic.

[0018] Preferably, the liquid conducting channel is in a straight cylindrical shape.

[0019] Preferably, the separator is in sheet shape.

[0020] Preferably, the partition, the liquid guiding channel and the lower plastic are integrally formed.

[0021] Preferably, the upper surface of the separator gradually becomes thinner from a side away from the first through hole to a side close to the first through hole.

[0022] Preferably, the upper surface of the separator is funnel-shaped with a bottom angle of 150°-175°.

[0023] Preferably, the ratio of the sum of the second through hole areas, the first through hole area and the through hole area of ​​the liquid guiding channel is 0.1-0.2:0.2-0.4:1.

[0024] Preferably, the ratio of the minimum distance between the partition and the bottom end of the liquid guiding channel to the minimum distance between the partition and the top end of the liquid guiding channel is 0.6-0.8:1.

[0025] Preferably, the inner diameter of the liquid guiding channel is 6-18 mm.

[0026] Preferably, the outer diameter of the liquid guiding channel is 6.8-22 mm.

[0027] Preferably, the length of the liquid guiding channel is 3-15 mm.

[0028] Preferably, the average thickness of the separator is 0.4-1.5 mm.

[0029] Preferably, the injection hole is a countersunk hole.

[0030] More preferably, part of the injection holes protrude downward from the cover plate and are located in the first cavity.

[0031] Preferably, a buffer tape is attached to the position of the tab corresponding to the second cavity.

[0032] Preferably, the explosion-proof hole is located between the positive terminal lead-out hole and the negative terminal lead-out hole.

[0033] Preferably, the injection hole is located between the explosion-proof hole and the positive terminal lead-out hole.

[0034] More preferably, the injection hole is close to the explosion-proof hole and away from the positive terminal lead-out hole.

[0035] The aperture of the liquid conducting channel of the secondary battery of the present invention close to the tab is large. Compared with the prior art structure in which the liquid injection channel and the liquid injection cavity form a large internal cavity and a small channel outlet, the tab is not easy to block the liquid conducting channel with a large aperture.

[0036] The secondary battery of the present invention is arranged between the first cavity and the second cavity through a separator, and the second cavity is arranged opposite to the pole ear, so that the pole ear is not easy to fit the separator, which can prevent the pole ear and the separator from fitting to block the injection channel, and prevent the burrs of the pole ear from being electrically connected to the top cover to cause a short circuit in the battery; in addition, since there is a certain distance between the separator and the pole ear under the second cavity, a buffer tape is also attached to the position of the pole ear corresponding to the second cavity, which can prevent the electrolyte from damaging the pole ear or the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a three-dimensional assembly diagram of a partial structure of a secondary battery of the present invention; Figure 2 It is a partial structural schematic diagram of the secondary battery of the present invention; Figure 3 for Figure 2 3D assembly drawing of Figure 4 for Figure 2 A partial enlarged view of .

[0038] Figure 5 A schematic diagram of the structure of the lower plastic of the secondary battery of the present invention; Figure 6 Another structural schematic diagram of the lower plastic of the secondary battery of the present invention; Figure 7 A schematic structural diagram of a liquid conducting channel of a secondary battery of the present invention; Figure 8 It is a schematic structural diagram of another liquid conducting channel of the secondary battery of the present invention; Fig. 9 It is a schematic structural diagram of another liquid conducting channel of the secondary battery of the present invention; Fig.10 It is a schematic structural diagram of another liquid conducting channel of the secondary battery of the present invention; Fig.11 It is a schematic structural diagram of another liquid conducting channel of the secondary battery of the present invention.

[0039] Explanation of the reference numerals: cover plate (1), liquid injection hole (11), explosion-proof hole (12), positive terminal lead-out hole (13), negative terminal lead-out hole (14), lower plastic (2), liquid guide channel (21), separator (211), first through hole (2111), second through hole (2112), first wall (212), second wall (213), guide slope (214), concave tooth (215), battery cell (3), pole ear (31), buffer tape (4), explosion-proof component (5), positive terminal assembly (6), negative terminal assembly (7), first cavity (a), second cavity (b). DETAILED DESCRIPTION

[0040] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0041] In the description of the present invention, it should be understood that the terms "upper", "middle", "lower", "top", "bottom", "around", "horizontal", "vertical", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. In addition, the meanings of "multiple" and "several" are two or more. Unless otherwise clearly and specifically defined, it cannot be understood as a limitation to the present invention.

[0042] In order to achieve the above object, the present invention provides a secondary battery. Figure 1-7 As shown, the secondary battery comprises: a cover plate 1, on which a liquid injection hole 11 is provided; a battery cell 3, which is arranged below the cover plate 1, and on which a pole ear 31 is provided; a lower plastic 2, which is arranged between the cover plate 1 and the battery cell 3, and on which a liquid guide channel 21 is provided at a position corresponding to the liquid injection hole 11; an explosion-proof component 5, which is fixedly connected to the cover plate 1 through an explosion-proof hole 12; a positive terminal assembly 6, which is fixedly connected to the cover plate 1 through a positive terminal lead-out hole 13; and a negative terminal assembly 7, which is fixedly connected to the cover plate 1 through a negative terminal lead-out hole 14. The shell is provided with a receiving cavity, the battery cell 3 is in the receiving cavity, the cover plate 1 and the lower plastic 2 block the receiving cavity of the shell; the liquid guiding channel 21 includes a first cavity a and a second cavity b; the first cavity a faces the cover plate 1, the second cavity b faces away from the cover plate 1, and the second cavity b is arranged opposite to the pole ear 31; the secondary battery also includes a separator 211, and the separator 211 has a plurality of through holes; the separator 211 is arranged between the first cavity a and the second cavity b.

[0043] The aperture of the liquid conducting channel 21 close to the tab 31 of the secondary battery of the present invention is large. Compared with the prior art structure in which the internal cavity between the liquid injection channel and the liquid injection cavity is large and the channel outlet is small, the tab 31 is not easy to block the liquid conducting channel 21 with a large aperture.

[0044] The secondary battery of the present invention forms a first cavity a and a second cavity b in the liquid guiding channel 21, and a separator 211 is arranged between the first cavity a and the second cavity b. The second cavity b is arranged opposite to the pole ear 31, so that there is a certain distance between the separator 211 and the pole ear 31 below the liquid guiding channel 21, so that the pole ear 31 is not easy to block the through hole of the separator 211, thereby avoiding the burrs of the pole ear 31 from being electrically connected to the top cover 1, causing a short circuit in the battery.

[0045] According to a particularly preferred embodiment of the present invention, the second cavity b of the secondary battery of the present invention comprises a side wall, and the side wall comprises a first wall 212 and a second wall 213 , and the first wall 212 and the second wall 213 form a step surface.

[0046] In some embodiments, see Fig. 9 As shown, the second cavity b of the secondary battery of the present invention includes a side wall, and the side wall includes a first wall 212 and a second wall 213. The first wall 212 and the second wall 213 form a step surface, so that the bottom surface area of ​​the second cavity b is reduced, and it is more difficult to fit with the pole ear 31, thereby preventing the pole ear 31 from fitting to the lower surface of the second cavity b and blocking the liquid guide channel 21.

[0047] According to a particularly preferred embodiment of the present invention, the second cavity b of the secondary battery of the present invention comprises a side wall, and the thickness of the side wall at one end close to the separator 211 is greater than the thickness of the side wall at one end close to the tab 31 .

[0048] In some embodiments, see Fig.10 As shown, the second cavity b of the secondary battery of the present invention includes a side wall, and the side of the side wall close to the pole ear 31 is chamfered to form a guide slope 214, so that the thickness of the side wall close to the separator 211 is greater than the thickness of the side wall close to the pole ear 31. Since the area of ​​the side wall close to the pole ear 31 is reduced, the bottom surface of the side wall is less likely to fit with the pole ear 31, thereby preventing the pole ear 31 from blocking the liquid guide channel 21.

[0049] According to a particularly preferred embodiment of the present invention, the second cavity of the secondary battery of the present invention comprises a side wall, and the bottom surface of the side wall is configured as a convex tooth surface formed by arc-shaped protrusions or a concave tooth surface formed by arc-shaped grooves.

[0050] The secondary battery of the present invention can prevent the grooves or protrusions from scratching the tabs 31 or the battery cell 3 by setting the grooves or protrusions on the bottom surface of the second cavity b to be arc-shaped.

[0051] In some embodiments, see Fig.11 As shown, there are several arc-shaped grooves 215 on the bottom surface of the second cavity b of the secondary battery of the present invention, so that the bottom surface of the second cavity b forms a concave tooth surface, which makes it more difficult for the bottom surface of the side wall to fit with the tab 31, thereby preventing the tab 31 from blocking the liquid guide channel 21.

[0052] In some embodiments, the bottom surface of the second cavity b of the secondary battery of the present invention has several arc-shaped protrusions, so that the bottom surface of the second cavity b forms a convex tooth surface, which makes it more difficult for the bottom surface of the side wall to fit with the tab 31, thereby preventing the tab 31 from blocking the liquid guide channel 21.

[0053] Similarly, in some embodiments, the bottom surface of the second cavity b of the secondary battery of the present invention can be uneven and wavy through a plurality of arc-shaped grooves and arc-shaped protrusions, which further makes it more difficult for the bottom surface of the side wall to fit with the pole ear 31, thereby preventing the pole ear 31 from blocking the liquid guide channel 21.

[0054] According to a particularly preferred embodiment of the present invention, the through holes include through holes of different sizes, see Figure 7 As shown, the separator 211 of the present invention includes a first through hole 2111 and a second through hole 2112 .

[0055] During the battery injection or negative pressure exhaust process, both the first through hole 2111 and the second through hole 2112 can be used for injection or exhaust.

[0056] According to a particularly preferred embodiment of the present invention, the first through hole 2111 is coaxially arranged with the liquid guiding channel 21 and the liquid injection hole 11. Figure 4 As shown, the first through hole 2111 of the present invention is coaxially arranged with the liquid guiding channel 21 and the liquid injection hole 11. By adopting the above-mentioned preferred solution, the electrolyte can be injected into the battery more quickly.

[0057] According to a particularly preferred embodiment of the present invention, the separator 211 of the present invention has a plurality of second through holes 2112 which are evenly distributed around the first through hole 2111 at equal angles. By adopting the above preferred solution, the electrolyte can be injected into the battery more quickly, and rapid air extraction can also be achieved. In addition, the second through holes 2112 of the present invention can well divert the electrolyte inside the liquid guiding channel 21, thereby increasing the flow range of the electrolyte and improving the injection efficiency.

[0058] In the present invention, as long as the purpose of the present invention can be achieved, there is no special requirement for the shapes of the first through hole 2111 and the second through hole 2112, as long as the electrolyte can pass through them smoothly, such as round, square, polygonal, polygonal arc, etc.

[0059] According to a preferred embodiment of the present invention, the first through hole 2111 of the present invention is a square. As shown in FIG8 , the first through hole 2111 of the present invention is a square, and the length of the square is greater than the aperture of the injection hole 11, and the width of the square is less than the aperture of the injection hole 11. By adopting the above preferred solution, the buffering effect of the separator 211 on the electrolyte can be improved, and the risk of the electrolyte damaging the tab or the battery cell can be further reduced.

[0060] It should be understood that the battery of the present invention is Figure 7-11 The structure of the liquid-conducting channel shown in the figure is used to exemplify or explain the principle of the present invention, but is not limited thereto. The partition 211 of the liquid-conducting channel can be set as Figure 7 or Figure 8 In the structure shown in FIG. 1 , the second cavity b of the liquid-conducting channel can be set to Figure 9-11 Any of the structures shown.

[0061] According to a particularly preferred embodiment of the present invention, the liquid guiding channel 21 of the present invention protrudes downward from the lower plastic 2. Figure 4 As shown, the liquid guiding channel 21 of the present invention protrudes downward from the lower plastic 2. By adopting the aforementioned preferred solution, most of the tabs below the lower plastic 2 can be located on the side of the liquid guiding channel 21, thereby reducing the risk of the tabs blocking the liquid guiding channel 21.

[0062] According to a particularly preferred embodiment of the present invention, the liquid conducting channel 21 of the present invention is in a straight cylindrical shape. By adopting the aforementioned preferred scheme, the liquid conducting channel 21 of the present invention is in a straight cylindrical shape, which can block the tabs on the side of the liquid conducting channel 21 from entering the interior of the liquid conducting channel 21; and, the aperture of the liquid conducting channel 21 close to the tabs of the present invention is large, and compared with the structure of the prior art in which the liquid injection channel and the liquid injection cavity form a large internal cavity and a small channel outlet, the tabs are not easy to block the liquid conducting channel 21 with a large aperture; at the same time, the large aperture of the liquid conducting channel 21 can enable the electrolyte to be injected into the battery faster.

[0063] According to a particularly preferred embodiment of the present invention, the separator 211 of the present invention is in the form of a sheet as a whole. By adopting the aforementioned preferred solution, the separator 211 occupies a small proportion in the vertical direction of the liquid-conducting channel 21, and the length of the liquid-conducting channel 21 can be further reduced, thereby reducing the space occupied by the liquid-conducting channel 21 inside the battery.

[0064] According to a particularly preferred embodiment of the present invention, the separator 211 of the present invention is integrally formed with the liquid guiding channel 21 and the lower plastic 2 .

[0065] See also Figure 5 and 6As shown, the separator 211 of the present invention is integrally formed with the liquid guiding channel 21 and the lower plastic 2, which can reduce the installation steps and simplify the process. In addition, the integral forming can also ensure the mechanical strength of the separator 211, the liquid guiding channel 21 and the lower plastic 2, and prevent the separator 211 and the liquid guiding channel 21 from falling off.

[0066] According to a particularly preferred embodiment of the present invention, the upper surface of the separator 211 of the present invention gradually becomes thinner from the side away from the first through hole 2111 to the side adjacent to the first through hole 2111. By adopting the aforementioned preferred solution, it is possible to ensure that after the injection is completed, the electrolyte will not remain on the upper surface of the separator 211. In addition, the lower surface of the separator 211 of the present invention is still flat, which is convenient for improving the mechanical strength of the separator 211 and preventing the separator 211 from falling off from the liquid guide channel 21.

[0067] According to a particularly preferred embodiment of the present invention, the upper surface of the separator 211 is funnel-shaped with a bottom angle of 150°-175°. By adopting the aforementioned preferred solution, while ensuring that the electrolyte will not remain on the upper surface of the separator 211 after the injection is completed, the separator 211 occupies a small proportion in the vertical direction of the liquid-conducting channel 21, so that there is space to increase the distance between the lower surface of the first through hole 2111 and the pole ear below the liquid-conducting channel 21, and the separator 211 occupies a small proportion in the vertical direction of the liquid-conducting channel 21, which can further reduce the length of the liquid-conducting channel 21, thereby reducing the space occupied by the liquid-conducting channel 21 inside the battery.

[0068] According to a particularly preferred embodiment of the present invention, the ratio of the sum of the areas of the second through holes 2112, the areas of the first through holes 2111 and the through hole area of ​​the liquid guiding channel 21 is 0.1-0.2:0.2-0.4:1.

[0069] If the area of ​​the first through hole 2111 of the separator 211 is too large, the separator 211 cannot buffer the electrolyte, and the electrolyte may damage the tab or the battery cell through the liquid guide channel 21, and at the same time affect the effect of the separator 211 blocking the tab from directly connecting to the top cover sheet; if the area of ​​the first through hole 2111 is too small, it is not conducive to the rapid injection of the electrolyte into the battery. If the area of ​​the second through hole 2112 of the separator 211 is too large, it affects the effect of the separator 211 blocking the tab from directly connecting to the top cover sheet; if the area of ​​the second through hole 2112 of the separator 211 is too small, it is not possible to divert the electrolyte inside the liquid guide channel 21, which is not conducive to the rapid injection of the electrolyte into the battery.

[0070] The present invention sets the ratio of the sum of the areas of the second through hole 2112, the area of ​​the first through hole 2111 and the area of ​​the through hole of the liquid guiding channel 21 to 0.1-0.2:0.2-0.4:1, so as to take into account the functions of the separator 211 in buffering the electrolyte and blocking the electrode ear from directly connecting to the top cover sheet, and also realize the rapid injection of electrolyte into the battery.

[0071] According to a particularly preferred embodiment of the present invention, the ratio of the minimum distance between the partition 211 and the bottom end of the liquid guiding channel 21 to the minimum distance between the partition 211 and the top end of the liquid guiding channel 21 is 0.6-0.8:1.

[0072] If the minimum distance between the separator 211 and the top of the liquid guiding channel 21 is too small, the effect of the separator 211 in buffering the electrolyte will be affected; if the minimum distance between the separator 211 and the bottom of the liquid guiding channel 21 is too small, the separator 211 will be close to the electrode ear below the liquid guiding channel 21, making it easy for the electrode ear to block the through hole of the separator 211.

[0073] The present invention can take into account the function of the separator 211 to buffer the electrolyte and prevent the electrode ear below the liquid guiding channel 21 from blocking the through hole of the separator 211 by setting the ratio of the minimum distance from the separator 211 to the bottom end of the liquid guiding channel 21 to the minimum distance from the separator 211 to the top end of the liquid guiding channel 21 to 0.6-0.8:1.

[0074] According to a particularly preferred embodiment of the present invention, the inner diameter of the liquid-conducting channel 21 of the present invention is 6-18 mm. In some embodiments, the inner diameter of the liquid-conducting channel 21 can be, but is not limited to, within the range of any two of 6 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, and 18 mm.

[0075] According to a particularly preferred embodiment of the present invention, the outer diameter of the liquid-conducting channel 21 of the present invention is 6.8-22 mm. In some embodiments, the value range of the outer diameter of the liquid-conducting channel 21 can be, but is not limited to, within the range of any two of 6.8 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, and 22 mm.

[0076] According to a particularly preferred embodiment of the present invention, the length of the liquid-conducting channel 21 of the present invention is 3-15 mm. In some embodiments, the length of the liquid-conducting channel 21 can be, but is not limited to, within the range of any two of 3 mm, 5 mm, 7 mm, 9 mm, 11 mm, 13 mm, and 15 mm.

[0077] It should be understood that the inner diameter and outer diameter mentioned in the present invention refer to equivalent diameters, and the length of the liquid guiding channel 21 mentioned in the present invention refers to the minimum length from the upper surface of the lower plastic 2 to the bottom surface of the liquid guiding channel 21 .

[0078] If the volume of the liquid-conducting channel 21 is too small, the speed of injecting the electrolyte into the battery will be affected; if the volume of the liquid-conducting channel 21 is too large, it will occupy the internal space of the battery, directly affecting the energy density of the battery. The present invention can prevent the liquid-conducting channel 21 from occupying the internal space of the battery due to its excessive volume by setting the inner diameter of the liquid-conducting channel 21 to 6-18 mm, the outer diameter to 6.8-22 mm, and the length to 3-15 mm, and can also enable the electrolyte to be quickly injected into the battery.

[0079] According to a particularly preferred embodiment of the present invention, the average thickness of the separator 211 of the present invention is 0.4-1.5 mm. By adopting the aforementioned preferred solution, the mechanical strength of the separator 211 can be guaranteed, the function of buffering the electrolyte can be achieved, and the separator 211 can also occupy a small proportion in the vertical direction of the liquid-conducting channel 21, and the length of the liquid-conducting channel 21 can be further reduced, thereby reducing the space occupied by the liquid-conducting channel 21 inside the battery.

[0080] In some embodiments, the average thickness of the separator 211 may be within a range including, but not limited to, any two of 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, and 1.5 mm.

[0081] See also Figure 4 , 5 As shown in , 6, the present invention sets a first cavity a and a second cavity b in the liquid guiding channel 21, and a partition 211 is set between the first cavity a and the second cavity b; the first cavity a faces the cover plate 1, and the second cavity b faces away from the cover plate 1.

[0082] The secondary battery of the present invention forms a first cavity a and a second cavity b in the liquid guide channel 21. When the electrolyte is injected through the injection hole 11, the electrolyte will first fill the first cavity a, then flow into the second cavity b through the partition 211 on the lower surface of the first cavity a, and then flow into the battery. The first cavity a of the present invention provides a certain buffer space for the injection of the electrolyte, which can prevent the electrolyte from directly damaging the pole ear. The second cavity b of the present invention allows the partition 211 to be at a certain distance from the pole ear 31 below the liquid guide channel to prevent the pole ear 31 from blocking the through hole of the partition 211.

[0083] According to a particularly preferred embodiment of the present invention, the injection hole 11 of the present invention is a countersunk hole. By adopting the above preferred solution, when the secondary battery of the present invention is installed with a sealing plug, the volume of the cover plate 1 protruding outward can be reduced, and it is also convenient for the sealing plug to enter the upper section of the countersunk hole, so as to facilitate the sealing of the injection hole.

[0084] According to a particularly preferred embodiment of the present invention, the injection hole 11 of the present invention protrudes downward from the cover plate 1 and is located in the first cavity a. By adopting the above preferred solution, the volume of the cover plate 1 protruding outward can be further reduced.

[0085] According to a particularly preferred embodiment of the present invention, a buffer tape 4 is attached to the tab 31 of the present invention at a position corresponding to the second cavity b. By adopting the above preferred solution, the tab 31 can be further prevented from being damaged by electrolyte during the battery filling process.

[0086] See also Figure 1 As shown, the battery cell 3 of the battery of the present invention is affixed with a buffer tape 4 at the position corresponding to the liquid conducting channel 21. If there is a tab 31 below the liquid conducting channel 21, the buffer tape 4 can be affixed to the tab 31; if the liquid conducting channel 21 is the battery cell 3, the buffer tape 4 can be affixed to the battery cell 3.

[0087] In the battery injection process, after the electrolyte passes through the liquid-conducting channel 21 and the through hole of the separator 211, the electrolyte flow rate in the separator 211 increases due to the large aperture of the through hole of the liquid-conducting channel 21 and the small aperture of the through hole of the separator 211. The secondary battery of the present invention is provided with a first cavity a and a second cavity b in the liquid-conducting channel 21, and the separator 211 is provided between the first cavity a and the second cavity b. The second cavity b makes a certain distance between the separator 211 and the tab 31 below the liquid-conducting channel 21, so as to prevent the electrolyte with increased flow rate passing through the separator 211 from directly damaging the tab 31.

[0088] In addition, the present invention can further prevent the electrolyte from damaging the pole ear 31 or the battery cell 3 during the liquid injection process by sticking the buffer tape 4; and the present invention can also further prevent the convex tooth surface, concave tooth surface or step surface formed on the bottom surface of the liquid guide channel 21 from scratching the pole ear 31 or the battery cell 3 by sticking the buffer tape 4.

[0089] The cover plate 1 of the present invention is also provided with an explosion-proof hole 12, a positive terminal lead-out hole 13, and a negative terminal lead-out hole 14. Figure 3 As shown, the lower plastic 2 of the present invention has through holes corresponding to the explosion-proof hole 12, the positive terminal lead-out hole 13, and the negative terminal lead-out hole 14. Unless otherwise clearly and specifically defined, the remaining components and structures of the lower plastic 2 of the present invention are well known to those skilled in the art and will not be described in detail here.

[0090] According to a particularly preferred embodiment of the present invention, the explosion-proof hole 12 of the present invention is located between the positive terminal lead-out hole 13 and the negative terminal lead-out hole 14 .

[0091] According to a particularly preferred embodiment of the present invention, the liquid injection hole 11 of the present invention is located between the explosion-proof hole 12 and the positive terminal lead-out hole 13 .

[0092] By adopting the aforementioned preferred scheme, the liquid injection hole 11 is located next to the explosion-proof hole 12, the liquid injection hole 11 and the explosion-proof hole 12 are in the middle of the cover plate 1, and the positive terminal lead-out hole 13 and the negative terminal lead-out hole 14 are at both ends of the cover plate 1, thereby reducing the contact between the electrode ear under the secondary battery and the liquid injection hole 11, and reducing the risk of the electrode ear entering the liquid guide channel 21 and blocking the through hole of the separator 211.

[0093] Furthermore, some secondary batteries in the art are positively charged through the top cover to increase the potential to protect the top cover. In the present invention, the injection hole 11 is located between the explosion-proof hole 12 and the positive terminal lead-out hole 13 so as to be close to the positive terminal lead-out hole 13 and away from the negative terminal lead-out hole 14. Even if the positive electrode ear below the injection hole 11 is electrically connected to the cover plate 1 through the injection hole 11, a short circuit will not be caused.

[0094] According to a particularly preferred embodiment of the present invention, the liquid injection hole 11 of the present invention is close to the explosion-proof hole 12 and away from the positive terminal lead-out hole 13. By adopting the aforementioned preferred solution, the positive electrode tab at the lower end of the positive terminal lead-out hole 13 can be further reduced from contacting the liquid injection hole 11, and the risk of the positive electrode tab entering the liquid guide channel 21 and blocking the through hole of the separator 211 can be reduced.

[0095] It should be understood that, unless otherwise clearly and specifically defined, the remaining components and structures of the battery of the present invention are well known to those skilled in the art and will not be described in detail herein.

[0096] The preferred embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A secondary battery, characterized in that: The secondary battery comprises: A cover plate, wherein a liquid injection hole is provided on the cover plate; A battery cell is arranged below the cover plate, and a tab is provided on the battery cell; The lower plastic is arranged between the cover plate and the battery core, and the lower plastic is provided with a liquid guide channel at a position corresponding to the liquid injection hole; An explosion-proof component is fixedly connected to the cover plate through an explosion-proof hole; The positive terminal assembly is fixedly connected to the cover plate through the positive terminal lead-out hole; A negative terminal assembly is fixedly connected to the cover plate through the negative terminal lead-out hole; The shell is provided with a receiving cavity, the battery cell is in the receiving cavity, and the cover plate and the lower plastic seal the receiving cavity of the shell; The liquid-conducting channel comprises a first cavity and a second cavity; the first cavity faces the cover plate, the second cavity faces away from the cover plate, and the second cavity is arranged opposite to the tab; The secondary battery further includes a separator having a plurality of through holes; The partition is disposed between the first cavity and the second cavity.

2. The secondary battery according to claim 1, characterized in that: The second cavity includes a side wall, and the side wall includes a first wall body and a second wall body, and the first wall body and the second wall body form a step surface.

3. The secondary battery according to claim 1, characterized in that: The second cavity includes a side wall, and the thickness of the side wall at one end close to the partition is greater than the thickness of the side wall at one end close to the tab.

4. The secondary battery according to claim 1, characterized in that: The second cavity comprises a side wall, and the bottom surface of the side wall is configured as a convex tooth surface formed by an arc-shaped protrusion or a concave tooth surface formed by an arc-shaped groove.

5. The secondary battery according to any one of claims 1 to 4, characterized in that: The through holes include a first through hole and a second through hole. The first through hole is coaxially arranged with the liquid guiding channel and the liquid injection hole. There are a plurality of second through holes which are evenly distributed around the first through hole at equal angle intervals.

6. The secondary battery according to any one of claims 1 to 4, characterized in that: The liquid-conducting channel protrudes downward from the lower plastic; and / or the liquid-conducting channel is in a straight-cylindrical shape, and the separator is in a sheet shape; and / or the separator, the liquid-conducting channel, and the lower plastic are integrally formed.

7. The secondary battery according to claim 5, characterized in that: The upper surface of the separator gradually becomes thinner from the side away from the first through hole to the side close to the first through hole; the upper surface of the separator is funnel-shaped with a bottom angle of 150°-175°.

8. The secondary battery according to claim 5, characterized in that: The ratio of the sum of the second through hole areas, the first through hole area and the through hole area of ​​the liquid conducting channel is 0.1-0.2:0.2-0.4:1; and / or the ratio of the minimum distance from the partition to the bottom end of the liquid conducting channel to the minimum distance from the partition to the top end of the liquid conducting channel is 0.6-0.8:

1.

9. The secondary battery according to claim 1, characterized in that: The inner diameter of the liquid-conducting channel is 6-18 mm; and / or the outer diameter of the liquid-conducting channel is 6.8-22 mm; and / or the length of the liquid-conducting channel is 3-15 mm; and / or the average thickness of the separator is 0.4-1.5 mm.

10. The secondary battery according to claim 1, characterized in that: The injection hole is a countersunk hole, part of which protrudes downward from the cover plate and is located in the first cavity; and / or the pole ear is affixed with a buffer tape at the position corresponding to the second cavity; and / or the explosion-proof hole is located between the positive terminal lead-out hole and the negative terminal lead-out hole, the injection hole is located between the explosion-proof hole and the positive terminal lead-out hole, and the injection hole is close to the explosion-proof hole and away from the positive terminal lead-out hole.

Images