Battery monomer, battery module and battery pack

Abstract

The utility model belongs to the technical field of batteries, and discloses a battery monomer, a battery module and a battery pack, the battery monomer comprises a battery shell and a pole group, the battery shell is provided with a containing cavity, the pole group is arranged in the containing cavity, the pole group comprises a pole lug and a pole piece, the pole lug comprises a first connecting belt and a second connecting belt, one end of the first connecting band is connected with one end of the second connecting band, the other end of the first connecting band is welded with the pole piece, the first connecting band and the pole piece are made of the same material, the other end of the second connecting band is welded with the battery shell, and the second connecting band and the battery shell are made of the same material; therefore, the welding effect of the tab and the pole piece and the welding effect of the tab and the battery shell are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to a battery monomer, battery module and battery package. BACKGROUND

[0002] The battery monomer usually includes battery shell and pole group, the battery shell is equipped with closed cavity, and the pole group is arranged in the cavity, the pole group usually includes the pole lug and the pole piece, one end of the pole lug is welded with the pole piece, and the other end of the pole lug is welded with the battery shell.

[0003] When the pole piece is aluminum material, and the battery shell is stainless steel material, the pole lug is usually stainless steel material, and the pole lug is fixedly connected with the battery shell through resistance welding or laser welding, and the pole lug is fixedly connected with the pole piece through ultrasonic metal welding.

[0004] Ultrasonic metal welding is a special method for connecting the same metal or different metal by using the mechanical vibration energy of ultrasonic frequency, when the metal is welded by ultrasonic, neither current is supplied to the workpiece, nor high-temperature heat source is applied to the workpiece, only mechanical energy is converted into internal energy, deformation energy and limited temperature rise under static pressure, so that the solid-phase welding of two welding base materials occurs at recrystallization temperature.

[0005] The recrystallization temperature of aluminum material is about 350 DEG C to 420 DEG C, and the recrystallization temperature of stainless steel is about 500 DEG C to 1000 DEG C, the recrystallization temperature of the two materials is quite different, therefore, when the stainless steel pole lug and the aluminum pole piece are ultrasonically welded, the pole piece is prone to fracture or the pole piece and the pole lug are prone to poor welding, thereby reducing the output rate of the battery monomer, and even shortening the service life of the battery monomer.

[0006] Therefore, it is urgent to provide a battery monomer, a battery module and a battery package to solve the above technical problems. INVENTION CONTENTS

[0007] The first purpose of the utility model is to provide a battery monomer, the welding effect of the pole lug and the pole piece of the battery monomer is higher, and the welding effect of the pole lug and the battery shell is higher.

[0008] To achieve this purpose, the utility model adopts the following technical scheme:

[0009] The battery monomer comprises:

[0010] The battery shell is provided with a cavity;

[0011] The pole group is arranged in the cavity, and the pole group comprises a pole lug and a pole tab. The pole lug comprises a first connecting strip and a second connecting strip. One end of the first connecting strip is connected to one end of the second connecting strip. The other end of the first connecting strip is welded to the pole tab, and the first connecting strip is made of the same material as the pole tab. The other end of the second connecting strip is welded to the battery shell, and the second connecting strip is made of the same material as the battery shell.

[0012] Optionally, the battery shell comprises a shell cover structure and a shell body. The shell cover structure comprises a cover plate, a conductive piece, and a pole post. The cover plate is connected to the shell body in a buckling manner. The cover plate and the shell body cooperate to form the cavity. The conductive piece is located in the cavity. One end of the pole post is connected to the conductive piece, and the other end of the pole post penetrates the cover plate.

[0013] The pole lug comprises a positive pole lug. The first connecting strip of the positive pole lug is a positive first connecting strip. The second connecting strip of the positive pole lug is a positive second connecting strip. The other end of the positive second connecting strip is welded to the conductive piece, and the positive second connecting strip is made of the same material as the conductive piece.

[0014] The pole tab comprises a positive pole tab. The other end of the positive first connecting strip is welded to the positive pole tab, and the positive first connecting strip is made of the same material as the positive pole tab.

[0015] Optionally, the pole lug further comprises a negative pole lug. The first connecting strip of the negative pole lug is a negative first connecting strip. The second connecting strip of the negative pole lug is a negative second connecting strip. The other end of the negative second connecting strip is welded to the inner wall of the shell body, and the negative second connecting strip is made of the same material as the shell body.

[0016] The pole tab further comprises a negative pole tab. The other end of the negative first connecting strip is welded to the negative pole tab, and the negative first connecting strip is made of the same material as the negative pole tab.

[0017] Optionally, the material of the negative pole tab is one of copper, aluminum, nickel, and nickel plating.

[0018] Optionally, the material of the positive pole tab is aluminum.

[0019] And / or, the material of the conductive piece is one of stainless steel, carbon steel, and aluminum.

[0020] And / or, the material of the shell body is one of stainless steel, carbon steel, and aluminum.

[0021] Optionally, one end of the first connecting strip is welded to one end of the second connecting strip, and the number of first welding points between one end of the first connecting strip and one end of the second connecting strip is two or more.

[0022] Optionally, the thickness of the first connecting strip and the second connecting strip is 0.05 mm or more.

[0023] Optionally, the other end of the first connecting strip is fixed to the pole tab through a second welding point. An insulating adhesive paper is attached to the pole tab, and the insulating adhesive paper covers the second welding point.

[0024] The second purpose of the utility model is to provide a battery module, the output rate of the battery module is higher, and the service life is longer.

[0025] In order to achieve the purpose, the utility model adopts the following technical scheme:

[0026] The battery module comprises the battery monomer.

[0027] The third purpose of the utility model is to provide a battery pack, the output rate of the battery pack is higher, and the service life is longer.

[0028] In order to achieve the purpose, the utility model adopts the following technical scheme:

[0029] The battery pack comprises the battery module.

[0030] The utility model has the advantages of:

[0031] The battery monomer provided by the utility model, the tab includes first connecting band and second connecting band, one end of first connecting band is connected with one end of second connecting band, the other end of first connecting band is welded with pole piece, and the material of first connecting band is same with pole piece, thereby can reduce the probability of the problem of the poor welding of first connecting band and pole piece, also reduce the probability of the problem of the fracture of first connecting band and pole piece when welding, the other end of second connecting band is welded with battery shell, and the material of second connecting band is same with battery shell, thereby can reduce the probability of the problem of the poor welding of second connecting band and battery shell, also reduce the probability of the problem of the fracture of second connecting band and battery shell when welding. Visible, the structural design is favorable for improving the output rate of battery monomer, and is favorable for prolonging the service life of battery monomer. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is the cross section structure schematic drawing of the battery monomer provided by the utility model,

[0033] Figure 2 It is the structure schematic drawing of the tab provided by the utility model,

[0034] Figure 3 It is the connecting structure schematic drawing of the tab and pole piece provided by the utility model,

[0035] Figure 4 It is the structure schematic drawing of the tab semi-finished product provided by the utility model.

[0036] In the drawing,

[0037] 100, battery case; 110, accommodating cavity; 120, case cover structure; 121, cover plate; 122, conductive member; 123, pole; 130, case; 210, tab; 211, first connecting band; 212, second connecting band; 213, positive tab; 2131, positive first connecting band; 2132, positive second connecting band; 214, negative tab; 2141, negative first connecting band; 2142, negative second connecting band; 220, pole piece; 221, positive pole piece; 222, negative pole piece; 230, separator; 310, first welding spot; 320, second welding spot; 400, insulating ring; 500, insulating adhesive paper. DETAILED DESCRIPTION

[0038] The utility model will be described in further detail below in combination with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the utility model, and not to limit the utility model. In addition, it should be noted that, in order to facilitate the description, only the part related to the utility model is shown in the drawings, not all structures.

[0039] In the description of the utility model, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship of two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0040] In the utility model, unless otherwise explicitly specified and limited, the first feature "on" or "below" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0041] In the description of the embodiment, the terms "up", "down", "right", etc. orientation or position relationship is based on the orientation or position relationship shown in the drawings, only for the convenience of description and simplification of operation, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second" are only used to distinguish in the description, and have no special meaning.

[0042] The battery monomer has high welding effect of the tab and the pole piece and high welding effect of the tab and the battery shell.

[0043] Specifically, as shown in Figure 1 and Figure 2 , the battery monomer comprises a battery shell 100 and a pole group, wherein the battery shell 100 is provided with a containing cavity 110, the pole group is arranged in the containing cavity 110, the pole group comprises a tab 210 and a pole piece 220, the tab 210 comprises a first connecting strip 211 and a second connecting strip 212, one end of the first connecting strip 211 is connected with one end of the second connecting strip 212, the other end of the first connecting strip 211 is welded with the pole piece 220, and the material of the first connecting strip 211 is the same as that of the pole piece 220, the other end of the second connecting strip 212 is welded with the battery shell 100, and the material of the second connecting strip 212 is the same as that of the battery shell 100.

[0044] Based on the above design, the tab 210 comprises the first connecting strip 211 and the second connecting strip 212, one end of the first connecting strip 211 is connected with one end of the second connecting strip 212, the other end of the first connecting strip 211 is welded with the pole piece 220, and the material of the first connecting strip 211 is the same as that of the pole piece 220, thereby reducing the probability of poor welding of the first connecting strip 211 and the pole piece 220, and reducing the probability of fracture of the first connecting strip 211 and the pole piece 220 when they are welded; the other end of the second connecting strip 212 is welded with the battery shell 100, and the material of the second connecting strip 212 is the same as that of the battery shell 100, thereby reducing the probability of poor welding of the second connecting strip 212 and the battery shell 100, and reducing the probability of fracture of the second connecting strip 212 and the battery shell 100 when they are welded. It can be seen that the structural design is conducive to improving the output rate of the battery monomer and prolonging the service life of the battery monomer.

[0045] Further, as shown in Figure 2 , one end of the first connecting strip 211 is welded with one end of the second connecting strip 212, and the number of first welding points 310 between one end of the first connecting strip 211 and one end of the second connecting strip 212 is two or more, for example, the number of first welding points 310 can be two, six or eight, etc., to improve the stability of the connection of the first connecting strip 211 and the second connecting strip 212.

[0046] Further, the two or more first welding points 310 are uniformly distributed in the overlapping area of the first connecting strip 211 and the second connecting strip 212, to further improve the stability of the connection of the first connecting strip 211 and the second connecting strip 212.

[0047] Optionally, as shown in Figure 3As shown, the other end of the first connecting band 211 is fixed with the pole piece 220 through the second welding points 320, the number of the second welding points 320 is two or more, for example, the number of the second welding points 320 can be two, three or five, etc., so as to improve the connection stability of the first connecting band 211 and the pole piece 220.

[0048] Further, the two or more second welding points 320 are uniformly distributed in the area where the first connecting band 211 and the pole piece 220 overlap, so as to further improve the connection stability of the first connecting band 211 and the pole piece 220.

[0049] Optionally, the insulating adhesive tape 500 is attached on the pole piece 220, and the insulating adhesive tape 500 covers the second welding points 320. When the pole piece 220 and the first connecting band 211 are welded, burrs and protrusions are easily generated at the welding position of the pole piece 220 (i.e. the position of the second welding points 320). Covering the second welding points 320 with the insulating adhesive tape 500 can avoid the burrs and protrusions piercing the other pole pieces 220 adjacent to the pole piece 220, and reduce the probability of internal short circuit problem of the battery monomer.

[0050] Optionally, the thickness of the first connecting band 211 and the second connecting band 212 is 0.05 mm or more, for example, the thickness of the first connecting band 211 can be 0.05 mm, 0.1 mm or 0.15 mm, etc., and the thickness of the second connecting band 212 can be 0.05 mm, 0.1 mm or 0.15 mm, etc., so as to ensure that the first connecting band 211 and the second connecting band 212 have sufficient structural strength, and reduce the probability of fracture of the first connecting band 211 and the second connecting band 212. As a preferred solution, the thickness of the first connecting band 211 and the second connecting band 212 is 0.3 mm or less, so as to improve the welding effect of the first connecting band 211 and the pole piece 220, and the welding effect of the second connecting band 212 and the battery shell 100.

[0051] In actual production, a plurality of first connecting bands 211 and a plurality of second connecting bands 212 can be arranged alternately and welded in sequence to form a Figure 4 pole lug 210 semi-finished product as shown, and then the pole lug 210 semi-finished product is cut according to the use requirement to obtain a Figure 2 pole lug 210 finished product as shown.

[0052] Optionally, as shown in Figure 1As shown, the battery shell 100 comprises a shell cover structure 120 and a shell body 130, the shell cover structure 120 comprises a cover plate 121, a conductive piece 122 and a pole 123, the cover plate 121 is connected with the shell body 130 by buckling connection, the cover plate 121 cooperates with the shell body 130 to form a cavity 110, the conductive piece 122 is located in the cavity 110, one end of the pole 123 is connected with the conductive piece 122, and the other end of the pole 123 is arranged through the cover plate 121; the tab 210 comprises a positive tab 213, the first connecting strip 211 of the positive tab 213 is a positive first connecting strip 2131, the second connecting strip 212 of the positive tab 213 is a positive second connecting strip 2132, and the other end of the positive second connecting strip 2132 is welded with the conductive piece 122, and the material of the positive second connecting strip 2132 is the same as that of the conductive piece 122; the tab 220 comprises a positive tab 221, and the other end of the positive first connecting strip 2131 is welded with the positive tab 221, and the material of the positive first connecting strip 2131 is the same as that of the positive tab 221.

[0053] Further, the material of the positive tab 221 is aluminum, and therefore, the material of the positive first connecting strip 2131 is aluminum. The material of the conductive piece 122 is stainless steel, and therefore, the material of the positive second connecting strip 2132 is stainless steel. Of course, in other embodiments, the material of the conductive piece 122 can also be carbon steel or aluminum, etc., which is determined according to the situation.

[0054] Optionally, the tab 210 further comprises a negative tab 214, the first connecting strip 211 of the negative tab 214 is a negative first connecting strip 2141, the second connecting strip 212 of the negative tab 214 is a negative second connecting strip 2142, the other end of the negative second connecting strip 2142 is welded with the inner wall of the shell body 130, and the material of the negative second connecting strip 2142 is the same as that of the shell body 130; the tab 220 further comprises a negative tab 222, the other end of the negative first connecting strip 2141 is welded with the negative tab 222, and the material of the negative first connecting strip 2141 is the same as that of the negative tab 222.

[0055] Further, the material of the negative tab 222 is nickel, and therefore, the material of the negative first connecting strip 2141 is nickel. Of course, in other embodiments, the material of the negative tab 222 can also be copper, aluminum or nickel-plated, etc., which is determined according to the situation.

[0056] Further, the material of the shell body 130 is stainless steel, and therefore, the material of the negative second connecting strip 2142 is stainless steel. Of course, in other embodiments, the material of the shell body 130 can also be carbon steel or aluminum, etc., which is determined according to the situation.

[0057] It should be noted that the above-mentioned stainless steel material is not limited to existing stainless steel materials such as austenitic, ferritic and martensitic. The above-mentioned aluminum material is not limited to pure aluminum or alloy aluminum material.

[0058] In this embodiment, the materials of the shell 130, the negative second connecting band 2142, the conductive member 122 and the positive second connecting band 2132 are all stainless steel, which can avoid unstable chemical reactions between the shell 130, the negative second connecting band 2142, the conductive member 122 and the positive second connecting band 2132 and the electrolyte in the cavity 110, and has the effect of improving the use reliability of the battery monomer.

[0059] The battery monomer provided in this embodiment is suitable for cylindrical monomer batteries, square monomer batteries and special-shaped monomer batteries. The above-mentioned pole group can be a wound pole group or a non-wound pole group. The production process of the battery monomer provided in this embodiment will be briefly introduced below by taking the wound pole group as an example:

[0060] Please refer to Figure 1 , the positive and negative tabs 213 and 214 are prepared; one end of the positive first connecting band 2131 away from the positive second connecting band 2132 is ultrasonically welded to the positive sheet 221, one end of the negative first connecting band 2141 away from the negative second connecting band 2142 is welded to the negative sheet 222, the positive sheet 221, the diaphragm 230 and the negative sheet 222 are stacked and wound into a roll in sequence, and then the roll-shaped pole group is assembled into the shell 130; one end of the negative second connecting band 2142 away from the negative first connecting band 2141 is laser welded or resistance welded to the inner wall of the shell 130; the insulating ring 400 is placed on the side of the pole group away from the inner bottom wall of the shell 130, so that one end of the positive second connecting band 2132 away from the positive first connecting band 2131 passes through the through hole on the insulating ring 400, and one end of the positive second connecting band 2132 away from the positive first connecting band 2131 is laser welded or resistance welded to the conductive member 122; the electrolyte is injected into the shell 130, and the cover plate 121 is tightly sealed and fitted at the opening of the shell 130.

[0061] This embodiment also provides a battery module, which comprises the above-mentioned battery monomer, and the two ends of the tab 210 of the above-mentioned battery monomer are respectively welded to the pole sheet 220 and the battery shell 100. The material of the first connecting band 211 (i.e., the part of the tab 210 welded to the pole sheet 220) of the tab 210 is the same as that of the pole sheet 220, and the material of the second connecting band 212 (i.e., the part of the tab 210 welded to the battery shell 100) of the tab 210 is the same as that of the battery shell 100. Therefore, the welding effect of the tab 210 and the pole sheet 220 and the welding effect of the tab 210 and the battery shell 100 are high, which improves the output rate of the battery monomer and prolongs the service life of the battery monomer. Therefore, the battery module using the above-mentioned battery monomer has a high output rate and a long service life.

[0062] The embodiment also provides a battery pack, which comprises the battery module, so that the output rate of the battery pack is higher and the service life is longer.

[0063] Obviously, the above embodiments of the utility model are only examples for clearly illustrating the utility model, and are not a limitation on the embodiments of the utility model. For ordinary skilled in the art, various obvious changes, re-adjustment and replacement can be made without departing from the protection scope of the utility model. Here, all the embodiments need not and cannot be exhausted. Any modification, equivalent replacement and improvement made within the spirit and principle of the utility model should be included in the protection scope of the utility model claim.

Claims

1. A battery cell, characterized by The battery shell (100) comprises a cavity (110); The pole group comprises a pole lug (210) and a pole tab (220), the pole lug (210) comprises a first connecting strip (211) and a second connecting strip (212), one end of the first connecting strip (211) is connected with one end of the second connecting strip (212), the other end of the first connecting strip (211) is welded with the pole tab (220), and the first connecting strip (211) is made of the same material as the pole tab (220); the other end of the second connecting strip (212) is welded with the battery shell (100), and the second connecting strip (212) is made of the same material as the battery shell (100). The battery shell (100) comprises a cover structure (120) and a shell body (130), the cover structure (120) comprises a cover plate (121), a conductive piece (122) and a pole post (123), the cover plate (121) is connected with the shell body (130) in a buckling manner, the cover plate (121) cooperates with the shell body (130) to form the cavity (110), the conductive piece (122) is located in the cavity (110), and one end of the pole post (123) is connected with the conductive piece (122) and the other end penetrates through the cover plate (121); 2. The battery cell of claim 1, wherein, The pole lug (210) comprises a positive pole lug (213), the first connecting strip (211) of the positive pole lug (213) is a positive first connecting strip (2131), the second connecting strip (212) of the positive pole lug (213) is a positive second connecting strip (2132), the other end of the positive second connecting strip (2132) is welded with the conductive piece (122), and the positive second connecting strip (2132) is made of the same material as the conductive piece (122); The pole tab (220) comprises a positive pole tab (221), the other end of the positive first connecting strip (2131) is welded with the positive pole tab (221), and the positive first connecting strip (2131) is made of the same material as the positive pole tab (221). The pole lug (210) further comprises a negative pole lug (214), the first connecting strip (211) of the negative pole lug (214) is a negative first connecting strip (2141), the second connecting strip (212) of the negative pole lug (214) is a negative second connecting strip (2142), the other end of the negative second connecting strip (2142) is welded with an inner wall of the shell body (130), and the negative second connecting strip (2142) is made of the same material as the shell body (130); 3. The battery cell of claim 2, wherein, The pole tab (220) further comprises a negative pole tab (222), the other end of the negative first connecting strip (2141) is welded with the negative pole tab (222), and the negative first connecting strip (2141) is made of the same material as the negative pole tab (222). The material of the negative pole tab (222) is one of copper, aluminum, nickel and nickel plating.

4. The battery cell of claim 3, wherein, The material of the positive pole tab (221) is aluminum.

5. The battery cell according to any one of claims 2-4, characterized in that, ​ And / or, the material of the conductive piece (122) is one of stainless steel, carbon steel and aluminum. And / or, the material of the shell (130) is one of stainless steel, carbon steel and aluminum.

6. The battery cell of any one of claims 1-4, wherein, One end of the first connecting band (211) is welded with one end of the second connecting band (212), and the number of first welding points (310) between the one end of the first connecting band (211) and the one end of the second connecting band (212) is two or more.

7. The battery cell of any one of claims 1-4, wherein, The thickness of the first connecting band (211) and the second connecting band (212) is 0.05mm or more.

8. The battery cell of any one of claims 1-4, wherein, The other end of the first connecting band (211) is fixed with the pole piece (220) through a second welding point (320), and the pole piece (220) is attached with insulating adhesive tape (500) covering the second welding point (320).

9. A battery module, characterized by The battery cell of any one of claims 1-8.

10. A battery pack, characterized by, The battery module of claim 9.

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