Battery cell, battery and vehicle

Abstract

The utility model discloses an electrical core, battery and vehicle, electrical core includes electrical core body, one side of electrical core body is equipped with first positive pole tab and second positive pole tab that are arranged at interval, the opposite other side of electrical core body is equipped with first negative pole tab and second negative pole tab that are arranged at interval, one end, far away from the battery cell body, of the first positive electrode lug and one end, far away from the battery cell body, of the second positive electrode lug are welded with the positive electrode cover plate, and one end, far away from the battery cell body, of the first negative electrode lug and one end, far away from the battery cell body, of the second negative electrode lug are welded with the negative electrode cover plate; the length of the first positive electrode lug is greater than that of the second positive electrode lug, and the length of the first negative electrode lug is greater than that of the second negative electrode lug, so that the contact between the first positive electrode lug and the second positive electrode lug and the contact between the first negative electrode lug and the second negative electrode lug can be avoided; therefore, the first positive electrode lug, the second positive electrode lug, the first negative electrode lug and the second negative electrode lug are prevented from being fused, and the use safety of the battery can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery cell, a battery and a vehicle. Background Art

[0002] Lithium-ion batteries are currently widely used power batteries. As an important component of electric vehicles, their performance directly affects the normal use of electric vehicles. In order to improve the charging efficiency of lithium-ion batteries, high currents are generally used to power lithium-ion batteries. However, when lithium-ion batteries are working at high currents, the tabs will generate a lot of heat, causing the temperature of the tabs to rise rapidly. If the temperature is too high, the tabs are prone to fuse.

[0003] In order to prevent the tabs from melting, multiple tabs are generally arranged on the same side of the battery to reduce the thickness of the tabs and reduce the heat generated by the tabs. However, during the welding process of the tabs and the cover plate, adjacent tabs are easily in contact, which may cause the tabs to melt, resulting in low safety in the use of the battery. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a battery core that can improve the safety of battery use.

[0005] The utility model also provides a battery using the electric core.

[0006] The utility model also provides a vehicle using the battery.

[0007] According to the first aspect of the present invention, the battery cell in the embodiment includes:

[0008] A cell body, wherein a first positive electrode tab and a second positive electrode tab are provided at intervals on one side of the cell body, and a first negative electrode tab and a second negative electrode tab are provided at intervals on the other side opposite to the cell body, wherein an end of the first positive electrode tab away from the cell body and an end of the second positive electrode tab away from the cell body are both used for welding to a positive electrode cover plate, and an end of the first negative electrode tab away from the cell body and an end of the second negative electrode tab away from the cell body are both used for welding to a negative electrode cover plate;

[0009] Wherein, along the length direction of the battery cell body, the length of the first positive electrode tab is greater than the length of the second positive electrode tab, and the length of the first negative electrode tab is greater than the length of the second negative electrode tab.

[0010] The battery cell according to the first embodiment of the utility model has at least the following beneficial effects:

[0011] When welding the first positive electrode tab and the second positive electrode tab on the positive electrode cover plate, since the length of the first positive electrode tab is greater than the length of the second positive electrode tab, the operator can adjust the position between the first positive electrode tab and the positive electrode cover plate so that the distance between the welding position between the first positive electrode tab and the positive electrode cover plate and the welding position between the second positive electrode tab and the positive electrode cover plate increases, which can avoid the first positive electrode tab from contacting the second positive electrode tab, so as to prevent the first positive electrode tab and the second positive electrode tab from fusing; similarly, when welding the first negative electrode tab and the second negative electrode tab on the negative electrode cover plate, since the length of the first negative electrode tab is greater than the length of the second negative electrode tab, the operator can adjust the position between the first negative electrode tab and the negative electrode cover plate so that the distance between the welding position between the first negative electrode tab and the negative electrode cover plate and the welding position between the second negative electrode tab and the negative electrode cover plate increases, which can avoid the first negative electrode tab from contacting the second negative electrode tab, so as to prevent the first negative electrode tab and the second negative electrode tab from fusing, and improve the safety of battery use.

[0012] In other embodiments of the present invention, along the thickness direction of the battery cell body, the projection of the first positive electrode tab partially overlaps with the projection of the second positive electrode tab, or the projection of the first positive electrode tab does not overlap with the projection of the second positive electrode tab.

[0013] In other embodiments of the present invention, along the thickness direction of the battery cell body, the first positive electrode tab and the second positive electrode tab are spaced apart.

[0014] In other embodiments of the present invention, along the thickness direction of the battery cell body, the battery cell body has a first edge, and the first negative electrode tab and the first positive electrode tab are both arranged close to the first edge.

[0015] In other embodiments of the present invention, along the length direction of the battery body, the minimum distance between the central axis of the first positive electrode tab and the central axis of the battery body is d 1 The minimum distance between the central axis of the second positive electrode tab and the central axis of the battery cell body is d 2 , satisfy: d 1 <d 2 .

[0016] In other embodiments of the present utility model, the battery cell body includes a diaphragm, a first positive electrode sheet group, a second positive electrode sheet group, a first negative electrode sheet group and a second negative electrode sheet group, the first positive electrode sheet group includes a plurality of first positive electrode sheets, the second positive electrode sheet group includes a plurality of second positive electrode sheets, the first negative electrode sheet group includes a plurality of first negative electrode sheets, the second negative electrode sheet group includes a plurality of second negative electrode sheets, a plurality of the first positive electrode sheets and a plurality of the first negative electrode sheets are alternately stacked, a plurality of the second positive electrode sheets and a plurality of the second negative electrode sheets are alternately stacked, and the diaphragm is arranged between the first positive electrode sheet and the first negative electrode sheet, between the second positive electrode sheet and the second negative electrode sheet, and on the outer surface of the battery cell body;

[0017] Among them, the first positive electrode sheet is provided with a first positive pin, and multiple first positive pins are connected to form the first positive electrode lug; the second positive electrode sheet is provided with a second positive pin, and multiple second positive pins are connected to form the second positive electrode lug; the first negative electrode sheet is provided with a first negative electrode pin, and multiple first negative electrode pins are connected to form the first negative electrode lug; the second negative electrode sheet is provided with a second negative electrode pin, and multiple second negative electrode pins are connected to form the second negative electrode lug.

[0018] A battery according to an embodiment of the second aspect of the utility model comprises a shell, a positive electrode cover plate, a negative electrode cover plate and the battery cell according to the embodiment of the first aspect of the utility model, the shell being provided with a accommodating cavity having a first opening and a second opening, the positive electrode cover plate being provided to cover the first opening, the negative electrode cover plate being provided to cover the second opening, the battery cell body being accommodated in the accommodating cavity, the first positive electrode tab and the second positive electrode tab being respectively welded to the positive electrode cover plate, and the first negative electrode tab and the second negative electrode tab being respectively welded to the negative electrode cover plate.

[0019] The battery according to the second embodiment of the utility model has at least the following beneficial effects:

[0020] In a battery cell using an embodiment of the first aspect of the utility model, when welding the first positive electrode tab and the second positive electrode tab on the positive electrode cover plate, since the length of the first positive electrode tab is greater than the length of the second positive electrode tab, the operator can adjust the position between the first positive electrode tab and the positive electrode cover plate so that the distance between the welding position between the first positive electrode tab and the positive electrode cover plate and the welding position between the second positive electrode tab and the positive electrode cover plate increases, which can avoid the first positive electrode tab from contacting the second positive electrode tab, so as to prevent the first positive electrode tab and the second positive electrode tab from fusing; similarly, when welding the first negative electrode tab and the second negative electrode tab on the negative electrode cover plate, since the length of the first negative electrode tab is greater than the length of the second negative electrode tab, the operator can adjust the position between the first negative electrode tab and the negative electrode cover plate so that the distance between the welding position between the first negative electrode tab and the negative electrode cover plate and the welding position between the second negative electrode tab and the negative electrode cover plate increases, which can avoid the first negative electrode tab from contacting the second negative electrode tab, so as to prevent the first negative electrode tab and the second negative electrode tab from fusing, and the safety of battery use can be improved.

[0021] In other embodiments of the present invention, the first positive electrode tab is bent in a direction close to the middle position of the battery cell body.

[0022] In other embodiments of the present invention, the bending direction of the second positive electrode tab is the same as the bending direction of the first positive electrode tab.

[0023] In other embodiments of the present invention, a first weld mark is provided between the first positive electrode tab and the positive electrode cover plate, a second weld mark is provided between the second positive electrode tab and the positive electrode cover plate, and the first weld mark and the second weld mark are arranged diagonally.

[0024] The vehicle according to the embodiment of the third aspect of the utility model comprises the battery described in the embodiment of the second aspect of the utility model.

[0025] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0027] Figure 1 A schematic diagram of the internal structure of a battery according to an embodiment of the utility model;

[0028] Figure 2 It is a front view of the battery cell body of an embodiment of the utility model, showing a first positive electrode tab, a second positive electrode tab, a first negative electrode tab and a second negative electrode tab;

[0029] Figure 3 A top view of a battery cell according to an embodiment of the utility model;

[0030] Figure 4 This is a front view of the battery cell, the positive electrode cover plate, and the negative electrode cover plate when assembled according to an embodiment of the utility model;

[0031] Figure 5 It is a top view of the battery cell, the positive electrode cover plate, and the negative electrode cover plate when assembled according to an embodiment of the utility model;

[0032] Figure 6 It is a left side view of the battery cell of the embodiment of the utility model, showing the first positive electrode pin and the second positive electrode pin;

[0033] Figure 7 This is a right side view of the battery cell of an embodiment of the utility model, showing a first negative electrode pin and a second negative electrode pin.

[0034] Reference numerals:

[0035] Battery cell body 100, first positive electrode tab 101, second positive electrode tab 102, first negative electrode tab 103, second negative electrode tab 104, first positive electrode sheet group 110, first positive electrode sheet 111, first positive electrode pin 112, second positive electrode sheet group 120, second positive electrode sheet 121, second positive electrode pin 122, first negative electrode sheet group 130, first negative electrode sheet 131, first negative electrode pin 132, second negative electrode sheet group 140, second negative electrode sheet 141, second negative electrode pin 142, diaphragm 150, connecting portion 151, isolating portion 152;

[0036] Shell 200, accommodating cavity 210, first opening 220, second opening 230;

[0037] Positive electrode cover plate 300 , first weld mark 301 , second weld mark 302 , positive electrode post 303 , negative electrode cover plate 400 , third weld mark 401 , fourth weld mark 402 , negative electrode post 403 . DETAILED DESCRIPTION

[0038] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0039] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0040] In the description of the present utility model, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0041] In the description of the present utility model, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present utility model based on the specific content of the technical solution.

[0042] In the description of the utility model, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0043] As mentioned above, in order to improve the charging efficiency of lithium-ion batteries, high current is generally used to power lithium-ion batteries. However, when lithium-ion batteries are working at high current, the tabs will generate a lot of heat, causing the temperature of the tabs to rise. Excessive temperature of the tabs will cause the tabs to melt. In order to avoid the tabs from melting, multiple tabs are generally set on the same side of the battery to reduce the thickness of the tabs, so that the heat generated by the tabs is reduced. However, during the welding process of the tabs and the cover plate, adjacent tabs are easily in contact, which can easily cause the tabs to melt, resulting in low safety in the use of the battery. Based on this, the utility model proposes a battery cell. Since the length of the first positive pole tab 101 is greater than the length of the second positive pole tab 102, and the length of the first negative pole tab 103 is greater than the length of the second negative pole tab 104, the welding position between the first positive pole tab 101 and the positive pole cover plate 300 is different from the welding position between the second positive pole tab 102 and the positive pole cover plate 300, and the welding position between the first negative pole tab 103 and the negative pole cover plate 400 is different from the welding position between the second negative pole tab 104 and the negative pole cover plate 400, which can avoid the first positive pole tab 101, the second positive pole tab 102, the first negative pole tab 103 and the second negative pole tab 104 from melting, thereby improving the safety of battery use.

[0044] It should be noted that one end of the first positive electrode tab 101 and one end of the second positive electrode tab 102 are both welded to the positive electrode post 303 on the positive electrode cover 300, and one end of the first negative electrode tab 103 and one end of the second negative electrode tab 104 are both welded to the negative electrode post 403 on the negative electrode cover 400, which will not be described in detail here. The welding method includes but is not limited to resistance welding, laser welding or ultrasonic welding.

[0045] Reference Figure 2 , Figure 3, respectively showing a front view and a top view of a battery cell of an embodiment of the first aspect of the utility model. As shown in the figure, in this embodiment, a first positive pole tab 101 and a second positive pole tab 102 are provided on one side of the length direction of the battery cell body 100, and a first negative pole tab 103 and a second negative pole tab 104 are provided on the other side of the length direction of the battery cell body 100. Along the thickness direction of the battery cell body 100, the projection of the first positive pole tab 101 overlaps with the projection of the second positive pole tab 102, so that the first positive pole tab 101 only partially blocks the second positive pole tab 102. On the one hand, the distance between the first positive pole tab 101 and the second positive pole tab 102 in the width direction of the battery cell body 100 can be reduced so that the first positive pole tab 101 and the second positive pole tab 102 are not too far apart. The maximum distance of the second positive electrode tab 102 in the width direction of the battery cell body 100 is reduced, which is beneficial to reducing the size of the positive electrode column 303, thereby reducing the material cost of the positive electrode cover 300. On the other hand, due to the limited size of the positive electrode cover 300, when a liquid injection hole or an explosion-proof valve is provided on the positive electrode cover 300, the space available for welding the first positive electrode tab 101 and the second positive electrode tab 102 on the positive electrode cover 300 is limited, and the first positive electrode tab 101 and the second positive electrode tab 102 occupy most of the space of the positive electrode cover 300, which can prevent the first positive electrode tab 101 and the second positive electrode tab 102 from blocking the liquid injection hole or the explosion-proof valve.

[0046] Similarly, along the thickness direction of the battery cell body 100 , the projection of the first negative electrode tab 103 may also partially overlap with the projection of the second negative electrode tab 104 , thereby reducing the size of the negative electrode column 403 and thus reducing the material cost of the negative electrode cover 400 .

[0047] Of course, in some specific embodiments, in order to facilitate the heat dissipation of the first positive electrode tab 101 and the second positive electrode tab 102, along the thickness direction of the battery cell body 100, the projection of the first positive electrode tab 101 may not overlap with the projection of the second positive electrode tab 102 at all, that is, the first positive electrode tab 101 and the second positive electrode tab 102 are arranged at intervals along the width direction of the battery cell body 100 to improve the heat dissipation effect of the first positive electrode tab 101 and the second positive electrode tab 102. Similarly, in order to facilitate the heat dissipation of the first negative electrode tab 103 and the second negative electrode tab 104, the projection of the first negative electrode tab 103 may not overlap with the projection of the second negative electrode tab 104, which will not be repeated here.

[0048] Reference Figure 4 , Figure 5, respectively showing the front view and top view of the battery cell body 100, the positive electrode cover plate 300, and the negative electrode cover plate 400 of the embodiment of the utility model when assembled. The welding position between the first positive electrode tab 101 and the positive electrode cover plate 300 is the first weld mark 301, and the welding position between the second positive electrode tab 102 and the positive electrode cover plate 300 is the second weld mark 302. When the first weld mark 301 and the second weld mark 302 partially overlap, the heat generated by the first positive electrode tab 101 and the heat generated by the second positive electrode tab 102 are concentrated in the overlapping area of ​​the first weld mark 301 and the second weld mark 302. The heat in the overlapping area is too high and the first positive electrode tab 101 and the second positive electrode tab 102 are easily melted.

[0049] In order to avoid the overlap of the first weld mark 301 and the second weld mark 302, the length of the first positive electrode lug 101 of the battery of this embodiment is greater than the length of the second positive electrode lug 102, and the first weld mark 301 and the second weld mark 302 are spaced apart along the width direction of the positive electrode cover plate 300, which can reduce the occurrence of the first positive electrode lug 101 and the second positive electrode lug 102 being melted.

[0050] Similarly, the welding position between the first negative electrode tab 103 and the negative electrode cover plate 400 is the third weld mark 401, and the welding position between the second negative electrode tab 104 and the negative electrode cover plate 400 is the fourth weld mark 402. In order to avoid the overlap of the third weld mark 401 and the fourth weld mark 402, the length of the first negative electrode tab 103 of the present embodiment is greater than the length of the second negative electrode tab 104. Along the width direction of the positive electrode cover plate 300, the third weld mark 401 and the fourth weld mark 402 are spaced apart, which can reduce the occurrence of the first negative electrode tab 103 and the second negative electrode tab 104 being melted.

[0051] It should be noted that the width direction of the positive electrode cover plate 300 and the width direction of the negative electrode cover plate 400 are Figure 5 Left-right direction as shown in .

[0052] For example Figure 5As shown, along the thickness direction of the battery cell body 100, the battery cell body has a first side. In order to facilitate welding the positive electrode cover plate 300 and the negative electrode cover plate 400 on the battery cell body 100, the first positive electrode ear 101 and the first negative electrode ear 103 are both arranged along one side close to the first side of the battery cell body 100. In this way, when welding the positive electrode cover plate 300 and the negative electrode cover plate 400 on the battery cell body 100, the battery cell body 100, the positive electrode cover plate 300 and the negative electrode cover plate 400 can be placed horizontally, and the positive electrode cover plate 300 and the negative electrode cover plate 400 are respectively placed at both ends of the length direction of the battery cell body 100, and the placement direction of the battery cell body 100 is adjusted so that the first positive electrode The first positive pole tab 101 is located above the second positive pole tab 102, and the first negative pole tab 103 is located above the second negative pole tab 104. The end of the first positive pole tab 101 and the end of the second positive pole tab 102 are respectively pressed against the positive electrode cover plate 300, and the end of the first negative pole tab 103 and the end of the second negative pole tab 104 are respectively pressed against the negative electrode cover plate 400, and the first positive pole tab 101, the second positive pole tab 102, the first negative pole tab 103 and the second negative pole tab 104 are welded in sequence, without adjusting the relative positions of the positive electrode cover plate 300 and the negative electrode cover plate 400, so that the positive electrode cover plate 300 and the negative electrode cover plate 400 can be easily welded on the battery cell. Of course, in some specific embodiments, the first positive pole tab 101, the second positive pole tab 102, the first negative pole tab 103 and the second negative pole tab 104 can also be welded at the same time, which is not limited here.

[0053] It should be noted that the first weld mark 301 and the second weld mark 302 are arranged at intervals along the thickness direction and the width direction of the battery cell body 100. In the plane formed by the thickness direction and the width direction of the battery cell body 100, the first weld mark 301 and the second weld mark 302 are arranged diagonally, which can not only increase the heat dissipation space of the first positive electrode tab 101 and the second positive electrode tab 102, but also avoid the overlap of the first weld mark 301 and the second weld mark 302, so as to prevent the failure of the first weld mark 301 and the second weld mark 302, and improve the service life of the battery cell body 100.

[0054] It should be pointed out that each of the first positive electrode tab 101 and the second positive electrode tab 102 can be configured with at least one, and the number of the first positive electrode tab 101 and the number of the second positive electrode tab 102 can be equal or unequal. Similarly, each of the first negative electrode tab 103 and the second negative electrode tab 104 can be configured with at least one, and the number of the first negative electrode tab 103 and the number of the second negative electrode tab 104 can be equal or unequal, which will not be repeated here.

[0055] For example Figure 6 As shown, Figure 6The left side view of the battery cell body of the embodiment of the utility model is shown. In this embodiment, on the basis that the length of the first positive electrode tab 101 is greater than that of the second positive electrode tab 102, along the length direction of the battery cell body 100, the minimum distance between the central axis of the first positive electrode tab 101 and the central axis of the battery cell body 100 is d 1 The minimum distance between the central axis of the second positive electrode tab 102 and the central axis of the battery cell body 100 is d 2 , satisfy: d 1 <d 2 On the one hand, the distance between the first positive electrode tab 101 and the corresponding side wall of the accommodating cavity 210 in the width direction can be increased to avoid the first positive electrode tab 101 from contacting the shell 200. On the other hand, it is convenient to avoid the injection hole or the explosion-proof valve.

[0056] Reference Figure 6 , Figure 7 , Figure 7 The right side view of the battery cell body 100 of the embodiment of the utility model is shown, wherein: Figure 6 A first positive pin 112 and a second positive pin 122 are shown, Figure 7 A first negative pin 132 and a second negative pin 142 are shown. In this embodiment, the battery cell body 100 includes a diaphragm 150, a first positive electrode sheet group 110, a second positive electrode sheet group 120, a first negative electrode sheet group 130 and a second negative electrode sheet group 140, the first positive electrode sheet group 110 includes a plurality of first positive electrode sheets 111, the second positive electrode sheet group 120 includes a plurality of second positive electrode sheets 121, the first negative electrode sheet group 130 includes a plurality of first negative electrode sheets 131, the second negative electrode sheet group 140 includes a plurality of second negative electrode sheets 141, the plurality of first positive electrode sheets 111 and the plurality of first negative electrode sheets 131 are alternately stacked, the plurality of second positive electrode sheets 121 and the plurality of second negative electrode sheets 141 are alternately stacked, and the diaphragm 150 is arranged between the first positive electrode sheet 111 and the first negative electrode sheet 131, between the second positive electrode sheet 121 and the second negative electrode sheet 141, and on the outer surface of the battery cell body 100;

[0057] Among them, the first positive electrode plate 111 is provided with a first positive electrode pin 112, and multiple first positive electrode pins 112 are connected to form a first positive electrode ear 101; the second positive electrode plate 121 is provided with a second positive electrode pin 122, and multiple second positive electrode pins 122 are connected to form a second positive electrode ear 102; the first negative electrode plate 131 is provided with a first negative electrode pin 132, and multiple first negative electrode pins 132 are connected to form a first negative electrode ear 103; the second negative electrode plate 141 is provided with a second negative electrode pin 142, and multiple second negative electrode pins 142 are connected to form a second negative electrode ear 104.

[0058] When manufacturing the battery cell body 100, the diaphragm 150 is folded so that the diaphragm 150 forms a plurality of first separation grooves and a plurality of second separation grooves, and a plurality of second positive electrode sheets 121 and a plurality of second negative electrode sheets 141 are stacked from bottom to top, and the second positive electrode sheets 121 are accommodated in the corresponding first separation grooves, and the second negative electrode sheets 141 are accommodated in the corresponding second separation grooves, so as to pre-assemble the second positive electrode sheet group 120 and the second negative electrode sheet group 140, and then the diaphragm 150 is folded again so that the diaphragm 150 forms a plurality of third separation grooves and a plurality of fourth separation grooves, and then the plurality of second positive electrode sheets 121 and the second negative electrode sheets 141 are stacked from bottom to top. A plurality of first positive electrode sheets 111 and a plurality of first negative electrode sheets 131 are arranged, the first positive electrode sheet 111 is accommodated in the corresponding third isolation groove, and the first negative electrode sheet 131 is accommodated in the corresponding fourth isolation groove. Afterwards, a plurality of first positive electrode pins 112, a plurality of second positive electrode pins 122, a plurality of first negative electrode pins 132 and a plurality of second negative electrode pins 142 are welded respectively to form a first positive electrode tab 101, a second positive electrode tab 102, a first negative electrode tab 103 and a second negative electrode tab 104. The operation is simple, convenient and quick, and can improve the production efficiency of the battery body 100.

[0059] It should be pointed out that, compared with the conventional single-side single-pole ear battery body 100, taking the positive electrode ear as an example, when a plurality of positive electrode pins are gathered, the positive electrode pin at the top and the positive electrode pin at the bottom are generally close to the positive electrode pin at the middle position. In order to ensure the welding space after gathering, the positive electrode pin at the top and the positive electrode pin at the bottom need to be lengthened, resulting in an increase in the thickness of the positive electrode ear and a larger occupied space of the positive electrode ear. Based on this, the first positive electrode plate group 110 and the second positive electrode plate group 120 in this embodiment are arranged in layers, so that the distance between the plurality of first positive electrode pins 112 is relatively close. When the plurality of first positive electrode pins 112 are gathered, there is no need to lengthen the first positive electrode pin 112. After the plurality of first positive electrode pins 112 are gathered, there is enough welding space, which can facilitate the formation of the first positive electrode ear 101. Similarly, the distance between the plurality of second positive electrode pins 122 is also relatively close, and there is no need to lengthen the plurality of second positive electrode pins 122. After the plurality of second positive electrode pins 122 are gathered together, there is enough welding space to facilitate forming the second positive electrode tab 102. Similarly, the first negative electrode plate group 130 and the second negative electrode plate group 140 can also be arranged in layers, which will not be described in detail here.

[0060] It can be understood that when the diaphragm 150 is in the extended state, the diaphragm 150 has a sheet-like structure.

[0061] It should be noted that when the diaphragm 150 is in a folded state, the diaphragm 150 includes a connecting portion 151 and an isolating portion 152. The isolating portion 152 is sandwiched between adjacent negative electrode sheets and positive electrode sheets. The connecting portion 151 connects adjacent isolating portions 152, which can prevent relative shaking of multiple positive electrode sheets and multiple negative electrode sheets, thereby improving the connection strength of the battery cell body 100.

[0062] It should be pointed out that Figure 6 After welding, the plurality of first positive pins 112 are formed Figure 2 The first positive electrode tab 101, Figure 6 After welding, the plurality of second positive pins 122 are formed Figure 2 The second positive electrode tab 102, Figure 6 After welding, the plurality of first negative electrode pins 132 are formed. Figure 2 The first negative electrode tab 103, Figure 6 After welding, the plurality of second negative electrode pins 142 are formed. Figure 2 The second negative electrode tab 104 is not described in detail here. The welding method includes but is not limited to ultrasonic welding, resistance welding or laser welding.

[0063] As another implementation, the first positive electrode plate 111 may also be located between two adjacent second positive electrode plates 121 . Similarly, the first negative electrode plate may also be located between two adjacent second negative electrode plates 141 . Details are not repeated here.

[0064] Reference Figure 1 , shows a schematic diagram of the internal structure of the battery in the embodiment of the second aspect of the utility model, wherein the positive cover plate 300 and the negative cover plate 400 are connected to the shell 200 by welding. As shown in the figure, the embodiment of the second aspect of the utility model proposes a battery, including a shell 200, a positive cover plate 300, a negative cover plate 400 and a battery cell in the embodiment of the first aspect of the utility model, the shell 200 is provided with a accommodating cavity 210, the accommodating cavity 210 has a first opening 220 and a second opening 230, the first opening 220 and the second opening 230 are arranged opposite to each other along the length direction of the shell 200, the positive cover plate 300 is covered on the first opening 220, the negative cover plate 400 is covered on the second opening 230, the battery cell body 100 is accommodated in the accommodating cavity 210, and the first positive electrode The ear 101 and the second positive electrode ear 102 are welded to the positive electrode cover plate 300 respectively, and the first negative electrode ear 103 and the second negative electrode ear 104 are connected to the negative electrode cover plate 400 respectively, which can not only reduce the heat generated by the first positive electrode ear 101, the second positive electrode ear 102, the first negative electrode ear 103 and the second negative electrode ear 104, but also increase the heat dissipation speed of the first positive electrode ear 101, the second positive electrode ear 102, the first negative electrode ear 103 and the second negative electrode ear 104, which can avoid the occurrence of ear melting and welding mark failure, and can improve the safety of lithium-ion batteries.

[0065] In the battery cell of the first embodiment of the utility model, when the battery is operating at a high current, the current of the external charging device is shunted through the first negative pole tab 103 and the second negative pole tab 104 and transmitted to the negative pole cover 400, and the current in the laminated battery cell is shunted through the first positive pole tab 101 and the second positive pole tab 102 and transmitted to the positive pole cover 300. Since the first positive pole tab 101 and the second positive pole tab 102 are respectively welded to the positive pole cover 300, the heat generated by the first positive pole tab 101 and the second positive pole tab 102 can be dispersed to avoid the first positive pole tab 101 and the second positive pole tab 102 being melted. Similarly, the first negative pole tab 103 and the second negative pole tab 104 are respectively welded to the negative pole cover 400, which can disperse the heat generated by the first negative pole tab 103 and the second negative pole tab 104 to avoid the first negative pole tab 103 and the second negative pole tab 104 being melted, thereby improving the safety of battery use.

[0066] It should be noted that the length direction of the battery cell body 100 is the length direction of the shell 200. Figure 1 In the figure, the length direction of the battery cell body 100 is the left-right direction shown in the figure.

[0067] When assembling the battery, firstly, the battery cell body 100 is placed as a whole in the accommodating cavity 210. At this time, the first positive pole ear 101 and the second positive pole ear 102 both extend out of the accommodating cavity 210 through the first opening 220, and the first negative pole ear 103 and the second negative pole ear 104 both extend out of the accommodating cavity 210 through the second opening 230. Then, the first positive pole ear 101 and the second positive pole ear 102 are welded to the positive electrode cover plate 300 respectively, and the first negative pole ear 103 and the second negative pole ear 104 are welded to the negative electrode cover plate 400 respectively, so that the assembly of the first positive pole ear 101, the second positive pole ear 102, the first negative pole ear 103 and the second negative pole ear 104 can be completed. Then, the positive electrode cover plate 300 and the negative electrode cover plate 400 are welded to the shell 200 by welding, so that the accommodating cavity 210 is in a sealed state, and the assembly of the battery can be completed.

[0068] When the battery is discharged, part of the current of the cell body 100 flows to the positive electrode cover 300 through the first positive electrode tab 101, and another part of the current of the cell body 100 flows to the positive electrode cover 300 through the second positive electrode tab 102, and then converges through the positive electrode cover 300 to power the external circuit, and the circuit in the external circuit is shunted to the first negative electrode tab 103 and the second negative electrode tab 104 through the negative electrode cover 400. The heat generated by the first positive electrode tab 101 and the second positive electrode tab 102 is dispersed at different positions of the positive electrode cover 300, which can reduce the occurrence of the first positive electrode tab 101 and the second positive electrode tab 102 being melted. Similarly, the heat generated by the first negative electrode tab 103 and the second negative electrode tab 104 is dispersed at different positions of the negative electrode cover 400, which can reduce the occurrence of the first negative electrode tab 103 and the second negative electrode tab 104 being melted.

[0069] When the battery is charging, the current of the external charging device is shunted through the first negative electrode tab 103 and the second negative electrode tab 104 and transmitted to the negative electrode cover 400, and the current in the laminated battery cell is shunted through the first positive electrode tab 101 and the second positive electrode tab 102 and transmitted to the positive electrode cover 300, which can disperse the heat generated by the first positive electrode tab 101 and the second positive electrode tab 102 to avoid the first positive electrode tab 101 and the second positive electrode tab 102 being melted. Similarly, the heat generated by the first negative electrode tab 103 and the second negative electrode tab 104 can be dispersed to avoid the first negative electrode tab 103 and the second negative electrode tab 104 being melted, which can improve the safety of battery use.

[0070] Taking the positive electrode tab as an example, compared with the battery with a single-sided single-pole tab, assuming that the current passing through the first positive electrode tab 101 and the current passing through the second positive electrode tab 102 are equal, the current of the first positive electrode tab 101 of this embodiment is half of the current of the positive electrode tab of the traditional single-sided single-pole tab battery. According to Joule's law, the heat generated by the current passing through the conductor is proportional to the square of the current. The heat generated by the first positive electrode tab 101 of this embodiment is one-fourth of the heat generated by the positive electrode tab of the traditional single-sided single-pole tab battery. The battery of this embodiment can effectively reduce the heat generated by the positive electrode tab and the negative electrode tab.

[0071] In the present embodiment, the first positive electrode tab 101 and the second positive electrode tab 102 are bent from one side of the thickness direction of the shell 200 to the other side of the thickness direction of the shell 200. On the one hand, it can avoid the first positive electrode tab 101 from contacting the second positive electrode tab 102, thereby avoiding the concentration of heat generated by the first positive electrode tab 101 and the second positive electrode tab 102. On the other hand, it can avoid the first positive electrode tab 101 from contacting the shell 200, so as to prevent the positive electrode cover plate 300 from being conductive with the shell 200.

[0072] Specifically, after the first positive electrode tab 101 and the second positive electrode tab 102 are welded to the positive electrode cover plate 300, the first positive electrode tab 101 and the second positive electrode tab 102 can be bent in the same direction to reduce the minimum distance between the positive electrode cover plate 300 and the root of the first positive electrode tab 101 to ensure that the positive electrode cover plate 300 can cover the first opening 220, and then the positive electrode cover plate 300 and the shell 200 are connected by welding to seal the first opening 220.

[0073] It should be noted that the positive electrode cover plate 300 and the negative electrode cover plate 400 are both insulated from the housing 200 so that the battery can be used normally.

[0074] It can be understood that since the length of the first positive electrode lug 101 is greater than that of the second positive electrode lug 102, when the first positive electrode lug 101 and the second positive electrode lug 102 are bent in the same direction, the bending position of the second positive electrode lug 102 can avoid the bending position of the first positive electrode lug 101, thereby avoiding the first positive electrode lug 101 and the second positive electrode lug 102 from contacting each other, thereby avoiding the concentration of heat generated by the first positive electrode lug 101 and the second positive electrode lug 102, and preventing the first positive electrode lug 101 and the second positive electrode lug 102 from being melted, thereby improving the reliability of the battery lugs.

[0075] In this embodiment, in order to prevent the first positive electrode tab 101 from contacting the housing 200 , the first positive electrode tab 101 is bent in a direction close to the middle position of the battery cell body 100 to ensure that the battery can be used normally.

[0076] Specifically, when the positive electrode cover plate 300 is welded to the shell 200, the distance between the first weld mark 301 and the root of the first positive electrode tab 101 is equal to the distance between the second weld mark 302 and the root of the second positive electrode tab 102. Since the length of the first positive electrode tab 101 is greater than the length of the second positive electrode tab 102, the bending degree of the first positive electrode tab 101 is greater than the bending degree of the second positive electrode tab 102. If the first positive electrode tab 101 is bent in a direction away from the middle position of the battery cell body 100, the minimum distance between the bending position of the first positive electrode tab 101 and the corresponding side wall of the accommodating cavity 210 is too small, and the first positive electrode tab 101 is at risk of short-circuiting with the shell 200. Based on this, the first positive electrode tab 101 of the embodiment of the utility model is bent in a direction close to the middle position of the battery cell body 100, which can avoid the short-circuit between the first positive electrode tab 101 and the shell 200, so as to ensure that the battery can be used normally.

[0077] The third embodiment of the utility model proposes a vehicle, including the battery of the second embodiment of the utility model, wherein the battery is configured with multiple batteries, and the multiple batteries are connected in parallel or in series. Among them, the vehicle can be a private car, such as a sedan, SUV, MPV or pickup truck. The vehicle can also be an operating vehicle, such as a van, bus, small truck or large trailer. The vehicle can be a gasoline vehicle or a new energy vehicle. When the vehicle is a new energy vehicle, it can be a hybrid vehicle or a pure electric vehicle.

[0078] The embodiments of the utility model are described in detail above in conjunction with the accompanying drawings, but the utility model is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the utility model. In addition, the embodiments of the utility model and the features in the embodiments can be combined with each other without conflict.

Claims

1. A battery cell, characterized in that: include: A cell body, wherein a first positive electrode tab and a second positive electrode tab are provided at intervals on one side of the cell body, and a first negative electrode tab and a second negative electrode tab are provided at intervals on the other side opposite to the cell body, wherein an end of the first positive electrode tab away from the cell body and an end of the second positive electrode tab away from the cell body are both used for welding to a positive electrode cover plate, and an end of the first negative electrode tab away from the cell body and an end of the second negative electrode tab away from the cell body are both used for welding to a negative electrode cover plate; Wherein, along the length direction of the battery cell body, the length of the first positive electrode tab is greater than the length of the second positive electrode tab, and the length of the first negative electrode tab is greater than the length of the second negative electrode tab.

2. The battery cell according to claim 1, characterized in that: Along the thickness direction of the battery cell body, the projection of the first positive electrode tab partially overlaps with the projection of the second positive electrode tab, or the projection of the first positive electrode tab does not overlap with the projection of the second positive electrode tab.

3. The battery cell according to claim 1, characterized in that: The first positive electrode tab and the second positive electrode tab are arranged at intervals along the thickness direction of the battery cell body.

4. The battery cell according to claim 1, characterized in that: The battery cell body has a first side along the thickness direction of the battery cell body, and the first negative electrode tab and the first positive electrode tab are both arranged close to the first side.

5. The battery cell according to claim 1, characterized in that: Along the length direction of the battery cell body, the minimum distance between the central axis of the first positive electrode tab and the central axis of the battery cell body is d1, and the minimum distance between the central axis of the second positive electrode tab and the central axis of the battery cell body is d2, satisfying: d1<d2.

6. The battery cell according to claim 1, characterized in that: The battery cell body comprises a diaphragm, a first positive electrode sheet group, a second positive electrode sheet group, a first negative electrode sheet group and a second negative electrode sheet group, the first positive electrode sheet group comprises a plurality of first positive electrode sheets, the second positive electrode sheet group comprises a plurality of second positive electrode sheets, the first negative electrode sheet group comprises a plurality of first negative electrode sheets, the second negative electrode sheet group comprises a plurality of second negative electrode sheets, a plurality of the first positive electrode sheets and a plurality of the first negative electrode sheets are alternately stacked, a plurality of the second positive electrode sheets and a plurality of the second negative electrode sheets are alternately stacked, and the diaphragm is arranged between the first positive electrode sheet and the first negative electrode sheet, between the second positive electrode sheet and the second negative electrode sheet, and on the outer surface of the battery cell body; Among them, the first positive electrode sheet is provided with a first positive pin, and multiple first positive pins are connected to form the first positive electrode lug; the second positive electrode sheet is provided with a second positive pin, and multiple second positive pins are connected to form the second positive electrode lug; the first negative electrode sheet is provided with a first negative electrode pin, and multiple first negative electrode pins are connected to form the first negative electrode lug; the second negative electrode sheet is provided with a second negative electrode pin, and multiple second negative electrode pins are connected to form the second negative electrode lug.

7. A battery, characterized in that include: A shell, a positive electrode cover plate, a negative electrode cover plate, and a battery cell according to any one of claims 1 to 6, wherein the shell is provided with a accommodating cavity, the accommodating cavity has a first opening and a second opening, the positive electrode cover plate is covered at the first opening, the negative electrode cover plate is covered at the second opening, the battery cell body is accommodated in the accommodating cavity, the first positive electrode tab and the second positive electrode tab are respectively welded to the positive electrode cover plate, and the first negative electrode tab and the second negative electrode tab are respectively welded to the negative electrode cover plate.

8. The battery according to claim 7, characterized in that The first positive electrode tab is bent in a direction close to the middle position of the battery cell body.

9. The battery according to claim 8, characterized in that The bending direction of the second positive electrode tab is the same as the bending direction of the first positive electrode tab.

10. The battery according to claim 7, characterized in that A first weld mark is provided between the first positive electrode tab and the positive electrode cover plate, a second weld mark is provided between the second positive electrode tab and the positive electrode cover plate, and the first weld mark and the second weld mark are arranged diagonally.

11. A vehicle, characterized in that include: The battery according to any one of claims 7 to 10.

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