A secondary battery and its assembly process

Abstract

In order to overcome the problems of existing square batteries, the bending of the connecting piece occupies part of the space inside the shell, the low utilization rate of the space inside the shell, and the low energy density of the battery, the present application provides a secondary battery and its assembly process, the battery includes at least one top cover plate, at least one connecting piece and a pole core assembly, at least one end of the pole core assembly is provided with a first pole ear, the end of the first pole ear away from the pole core assembly is bent toward the pole core assembly, and a first space is formed between the first pole ear and the pole core assembly; a top cover plate is provided on the side of the first pole ear away from the pole core assembly, a pole column is provided on the top cover plate, and the first pole ear is connected to the pole column; a connecting piece is provided on the side of the top cover plate facing the pole core assembly, the connecting piece includes at least one metal piece, the metal piece is provided in the first space, and the side of the first pole ear away from the pole column is connected to the metal piece. The secondary battery provided by the present application reduces the space occupied by the bending of the connecting piece, improves the utilization rate of the internal space of the battery, and improves the energy density of the battery.

Description

Technical Field

[0001] The invention belongs to the technical field of batteries, and in particular relates to a secondary battery and an assembly process thereof. Background Art

[0002] Existing secondary batteries are mainly divided into three categories: cylindrical batteries, square batteries and soft-pack batteries. The square battery includes a shell, a pole core, a positive electrode connecting piece, a negative electrode connecting piece and a top cover plate. A positive electrode ear and a negative electrode ear are provided at one end of the pole core. The positive electrode ear and the negative electrode ear are both composed of multiple pieces of foil materials, such as the positive electrode ear is composed of an aluminum foil cluster formed by multiple pieces of aluminum foil, and the negative electrode ear is composed of a copper foil cluster formed by multiple pieces of copper foil. In the assembly process of the square battery, the aluminum foil cluster is pre-welded and the copper foil cluster is pre-welded, and then the positive electrode connecting piece is laser welded to the positive ear, and the negative electrode connecting piece is laser welded to the negative ear, and then the positive electrode connecting piece is bent, and the negative electrode ear connecting piece is bent, and then the positive electrode connecting piece is welded to the positive column on the top cover plate, and the negative electrode connecting piece is welded to the negative column on the top cover plate. The battery composed of the above assembly process occupies part of the space inside the shell due to the bending of the connecting piece, the space utilization rate inside the shell is low, and the energy density of the battery is low. Summary of the invention

[0003] The present invention aims to solve the problem of existing square batteries, in which the bent connecting pieces occupy part of the space inside the shell, the low space utilization rate inside the shell, and the low energy density of the battery. The present application provides a secondary battery and its assembly process.

[0004] To solve the above technical problems, the present application provides a secondary battery, comprising at least one top cover plate, at least one connecting member and a pole core assembly, wherein a first pole ear is provided at at least one end of the pole core assembly, and the end of the first pole ear away from the pole core assembly is bent toward the direction of the pole core assembly, and a first space is formed between the first pole ear and the pole core assembly; the top cover plate is provided on the side of the first pole ear away from the pole core assembly, a pole column is provided on the top cover plate, and the first pole ear is connected to the pole column; the connecting member is provided on the side of the top cover plate facing the pole core assembly, the connecting member includes at least one metal member, the metal member is provided in the first space, and the side of the first pole ear away from the pole column is connected to the metal member.

[0005] Preferably, the connecting member further includes a first connecting plate, the metal member is disposed on the first connecting plate, and the first connecting plate is disposed between the first pole lug and the pole core assembly.

[0006] Preferably, two of the metal parts are arranged on the first connecting plate, and the two metal parts are respectively a first metal part and a second metal part. A second pole ear is also arranged at one end of the pole core assembly, and the second pole ear and the first pole ear are arranged at the same end of the pole core assembly. The first metal part is arranged in the first space, and the second pole ear is bent toward the pole core assembly at one end away from the pole core assembly, and a second space is formed between the second pole ear and the pole core assembly. The second metal part is arranged in the second space, and the second metal part is connected to the second pole ear; a first pole column and a second pole column are arranged on the top cover plate, and the side of the first pole ear facing away from the first metal part is connected to the first pole column, and the side of the second pole ear facing away from the second metal part is connected to the second pole column.

[0007] Preferably, the connecting member also includes a second connecting plate, the first connecting plate is provided at at least one end of the second connecting plate, and the angle between the first connecting plate and the second connecting plate is greater than 0; at least one of the metal parts is provided on the first connecting plate, the pole core assembly includes at least two pole cores, the second connecting plate is provided between the two pole cores, and the first connecting plate is provided on the side of the pole core facing the top cover plate.

[0008] Preferably, the angle between the second connecting plate and the first connecting plate is 90±10°.

[0009] Preferably, a second pole ear is provided at one end of the pole core assembly away from the first pole ear; a first connecting plate is provided at each of the two ends of the second connecting plate, each of the first connecting plates is provided with the metal part, the two metal parts are respectively a first metal part and a second metal part, the first metal part is arranged in the first space, the second pole ear is bent toward the pole core assembly at one end away from the pole core assembly, a second space is formed between the second pole ear and the pole core assembly, the second metal part is arranged in the second space, and the second metal part is connected to the second pole ear.

[0010] Preferably, the battery includes two top cover plates, namely a first top cover plate and a second top cover plate, the first top cover plate is provided with a first pole, the second top cover plate is provided with a second pole, the first pole ear is connected to the first pole on a side away from the first metal part, and the second pole ear is connected to the second pole on a side away from the second metal part.

[0011] Preferably, a heat insulation layer is coated on one side of the second connecting plate facing the pole core, which is used for heat insulation of the two pole cores.

[0012] Preferably, the connecting member also includes two third connecting plates, the first connecting plate includes a first end and a second end, the first end is connected to one end of one of the third connecting plates, and the second end is connected to one end of the other third connecting plate; the two third connecting plates are arranged opposite to each other, and the two third connecting plates are respectively arranged on both sides of the pole core assembly.

[0013] Preferably, the top cover plate is also provided with a mounting hole, an insulating member and a pole cap, the pole includes a column portion and a connecting portion, the column portion passes through the mounting hole, the connecting portion is connected to a side of the top cover plate facing the pole core assembly, the insulating member is arranged on a side of the connecting portion facing the pole core assembly, a channel is provided in the column portion, the pole cap is arranged in the channel, and the pole cap is connected to the column portion.

[0014] Preferably, a pole lug glue is provided on a side of the first pole lug facing the top cover plate, and the pole lug glue is provided at two ends of the first pole lug.

[0015] On the other hand, the present application provides an assembly process of the secondary battery described above, comprising the following steps:

[0016] The pole core assembly is provided with a first pole ear and a second pole ear, and the connecting member includes a first metal member and a second metal member, the first metal member is placed in the first space formed by bending the first pole ear toward the inside of the pole core assembly, and the second metal member is placed in the second space formed by bending the second pole ear toward the inside of the pole core assembly, and then pole ear glue is respectively attached to both ends of the first pole ear and the second pole ear;

[0017] Then, the pole core assembly is placed in the shell and the top cover plate is pressed, and a laser is used to perform laser welding from top to bottom above the first pole on the top cover plate to weld the first pole, the first pole lug and the first metal part together, and a laser is used to perform laser welding from top to bottom above the second pole on the top cover plate to weld the second pole, the second pole lug and the second metal part together;

[0018] Finally, the shell and the top cover are welded around the perimeter.

[0019] Beneficial effects:

[0020] Compared with the prior art, the present application provides a secondary battery in which a connecting piece is arranged on the side of the top cover plate facing the pole core assembly, and the connecting piece plays a supporting role. The pole core assembly is damaged when the top cover plate is placed for press-fitting. The end of the first pole ear away from the pole core assembly is bent toward the direction of the pole core assembly, and a first space is formed between the first pole ear and the pole core assembly. The metal part in the connecting piece is arranged in the first space. When the pole column and the first pole ear are laser welded, the arrangement of the metal part can also prevent the pole core assembly from burning. Compared with the existing battery, the secondary battery provided by the present application reduces the use of connecting sheets, reduces the cost of the battery, reduces the space occupied by the bending of the connecting sheet, improves the utilization rate of the internal space of the battery, and improves the energy density of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the explosion structure of a secondary battery provided by the present application;

[0022] Figure 2 This is a schematic diagram of the structure of the secondary battery-second embodiment-connector provided by the present application;

[0023] Figure 3 This is a schematic diagram of the assembly structure of the secondary battery-core and connector provided in the present application;

[0024] Figure 4 It is a schematic diagram of the explosion structure of the secondary battery-top cover plate provided in this application;

[0025] Figure 5 This is a schematic diagram of the structure of the connector of the secondary battery - the fourth embodiment - provided in the present application.

[0026] Among them, 1. pole core assembly; 101. first pole ear; 102. protective glue; 103. pole core; 104. second pole ear; 2. connecting piece; 201. second connecting plate; 202. first connecting plate; 203. metal piece; 204. third connecting plate; 3. top cover plate; 301. first top cover plate; 3011. first pole; 302. second top cover plate; 3021. second pole; 303. mounting hole; 304. insulating piece; 305. pole cap; 306. column part; 307. connecting part; 308. channel; 4. shell; 401. opening. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] On the one hand, a secondary battery provided in the first embodiment of the present application comprises at least one top cover plate 3, at least one connector 2 and a pole core assembly 1, wherein a first pole ear 101 is provided at at least one end of the pole core assembly 1, and the end of the first pole ear 101 away from the pole core assembly 1 is bent toward the inside of the pole core assembly 1, and a first space is formed between the first pole ear 101 and the pole core assembly 1; the top cover plate 3 is provided on the side of the first pole ear 101 away from the pole core assembly 1, and a pole column is provided on the top cover plate 3, and the first pole ear 101 is connected to the pole column; the connector 2 is provided on the side of the top cover plate 3 facing the pole core assembly 1, and the connector 2 comprises at least one metal member 203, and the metal member 203 is provided in the first space, and the side of the first pole ear 101 away from the pole column is connected to the metal member 203.

[0029] Specifically, the battery includes a housing 4, at least one top cover plate 3, at least one connector 2 and a pole core assembly 1. A receiving cavity is provided inside the housing 4, and the pole core assembly 1 is provided in the receiving cavity. When the battery includes two top cover plates 3, an opening 401 is provided at each end of the housing 4, and the two openings 401 are connected to the receiving cavity; when the battery includes one top cover plate 3, the structure of the housing 4 is that an opening 401 is provided at one end, and the opening 401 is connected to the receiving cavity.

[0030] A metal part 203 is arranged on the connecting part 2. The metal part 203 is made of metal and has a conductive function. The end of the first pole ear 101 away from the pole core assembly 1 is bent toward the direction of the pole core assembly 1. A first space is formed between the first pole ear 101 and the pole core assembly 1. The metal part 203 is arranged in the first space. At the same time, one side of the first pole ear 101 is connected to the metal part 203, and the side of the first pole ear 101 away from the metal part 203 is connected to the pole. During the laser welding process between the pole and the first pole ear 101, the metal part 203 also prevents the pole core assembly 1 from being burned. The setting of the metal part 203 ensures the normal power supply of the battery and the external circuit.

[0031] The secondary battery provided by the present application has a connector 2 arranged on the side of the top cover plate 3 facing the pole core assembly 1, and the connector 2 plays a supporting role. The pole core assembly 1 is damaged when the top cover plate 3 is placed for press-fitting. The end of the first pole ear 101 away from the pole core assembly 1 is bent toward the direction of the pole core assembly 1, and a first space is formed between the first pole ear 101 and the pole core assembly 1. The metal part 203 is arranged in the first space. When the pole column and the first pole ear 101 are laser welded, the arrangement of the metal part 203 can also prevent the pole core assembly 1 from being burned. Compared with the existing battery, the secondary battery provided by the present application reduces the use of connecting sheets, reduces the cost of the battery, reduces the space occupied by the bending of the connecting sheets, increases the length of the pole sheets in the pole core assembly 1, improves the utilization rate of the internal space of the battery, and improves the energy density of the battery.

[0032] In the first embodiment, the connecting member 2 further includes a first connecting plate 202 , on which the metal member 203 is disposed, and the first connecting plate 202 is disposed between the first pole lug 101 and the pole core assembly 1 .

[0033] The connector 2 includes a first connector plate 202, on which a metal member 203 is disposed, and the angle between the first connector plate 202 and the metal member 203 is 0. It can be understood that the metal member 203 can be fixed on the surface of the first connector plate 202, or the metal member 203 can be embedded and fixed in the first connector plate 202. In the connector 2 of this structure, the first connector plate 202 is disposed between the first pole ear 101 and the pole core assembly 1, and plays a supporting role to prevent the first connector plate 202 from pressing on the pole core assembly 1 when the top cover plate 3 is pressed; at the same time, the first connector plate 202 also prevents the pole core assembly 1 from being burned when the pole column and the first pole ear 101 are laser welded.

[0034] In the first embodiment, the first connecting plate 202 is made of insulating material.

[0035] The first connecting plate 202 is made of insulating material to prevent the battery from short circuiting.

[0036] In the first embodiment, two metal parts 203 are arranged on the first connecting plate 202, and the two metal parts 203 are respectively a first metal part and a second metal part. A second pole ear 104 is also arranged at one end of the pole core assembly 1, and the second pole ear 104 and the first pole ear 101 are arranged at the same end of the pole core assembly 1, the first metal part is arranged in the first space, and the end of the second pole ear 104 away from the pole core assembly 1 is bent toward the pole core assembly 1, and a second space is formed between the second pole ear 104 and the pole core assembly 1, and the second metal part is arranged in the second space, and the second metal part is connected to the second pole ear 104; a first pole column 3011 and a second pole column 3021 are arranged on the top cover plate 3, and the side of the first pole ear 101 facing away from the first metal part is connected to the first pole column 3011, and the side of the second pole ear 104 facing away from the second metal part is connected to the second pole column 3021.

[0037] A first pole ear 101 and a second pole ear 104 are respectively arranged on the same side of the pole core assembly 1, the first metal part is connected to the first pole ear 101, and the second pole ear 104 is connected to the second metal part. The first metal part can prevent the first pole column 3011 on the top cover plate 3 from being welded to the first pole ear 101 to prevent the pole core 103 near the position of the first pole ear 101 from being burned, and the second metal part can prevent the second pole column 3021 on the top cover plate 3 from being welded to the second pole ear 104 to prevent the pole core 103 near the position of the second pole ear 104 from being burned.

[0038] In the first embodiment, a pole tab glue is provided on a side of the first pole tab 101 facing the top cover plate 3 , and the pole tab glue is provided at two ends of the first pole tab 101 .

[0039] The tab glue has a bonding effect, and the tab glue is attached to both ends of the first tab 101 to protect the first tab 101 .

[0040] In the first embodiment, a pole tab glue is provided on a side of the second pole tab 104 facing the top cover plate 3 , and the pole tab glue is provided at two ends of the second pole tab 104 .

[0041] The tab glue has a bonding effect, and the tab glue is attached to both ends of the second tab 104 to protect the second tab 104 .

[0042] In the first embodiment, the cross-sectional shapes of the first pole 3011 and the second pole 3021 on the top cover plate 3 are circular or polygonal.

[0043] In the first embodiment, the top cover plate 3 is further provided with a mounting hole 303, an insulating member 304 and a pole cap 305, and the pole includes a column portion 306 and a connecting portion 307, the column portion 306 passes through the mounting hole 303, the connecting portion 307 is connected to the side of the top cover plate 3 facing the pole core assembly 1, the insulating member 304 is arranged on the side of the connecting portion 307 facing the pole core assembly 1, a channel 308 is arranged in the column portion 306, the pole cap 305 is arranged in the channel 308, and the pole cap 305 is connected to the column portion 306.

[0044] like Figure 4 As shown, the connecting portion 307 is a planar structure, and the cross-section of the connecting portion 307 is a polygon, a circle, an ellipse, an arc, or a closed figure composed of arcs and line segments; the connecting portion 307 is mainly used for welding with the pole ear, and this structure can weld the pole ear and the pole together using less laser welding energy. A channel 308 is provided inside the column 306, and the pole cap 305 is provided in the channel 308. The pole cap 305 is connected to the column 306, that is, during assembly, the pole cap 305 is directly welded to the inner wall of the channel 308 of the column 306 away from the periphery of the pole core assembly 1, so as to realize the electrical connection between the battery and the external power supply. It should be noted that the cross-sectional shape of the column 306 can be a polygon, a circle, an ellipse, or a closed figure composed of arcs and line segments; the cross-sectional shape of the pole cap 305 can be a polygon, a circle, an ellipse, or a closed figure composed of arcs and line segments.

[0045] It should be noted that the side of the pole cap 305 facing the pole core assembly 1 may be connected to the connecting portion 307 or may not be connected, and this application does not limit this.

[0046] The insulating member 304 is arranged on the side of the connecting portion 307 facing the pole core assembly 1 to prevent the battery from short circuiting.

[0047] Second embodiment

[0048] like Figure 1-3 As shown, the second embodiment of the present application provides a secondary battery, and the structure of the first connecting plate 202 in the battery is different from that in the first embodiment, specifically: in the second embodiment, the connecting member 2 also includes a second connecting plate 201, and the first connecting plate 202 is provided at at least one end of the second connecting plate 201, and the angle between the first connecting plate 202 and the second connecting plate 201 is greater than 0; at least one metal member 203 is provided on the first connecting plate 202, the pole core assembly 1 includes at least two pole cores 103, the second connecting plate 201 is arranged between the two pole cores 103, and the first connecting plate 202 is arranged on the side of the pole core 103 facing the top cover plate 3.

[0049] Specifically, in the second embodiment, the connecting member 2 has the following two structures. The first structure includes a second connecting plate 201 and a first connecting plate 202. The first connecting plate 202 is arranged at one end of the second connecting plate 201, and the angle between the second connecting plate 201 and the first connecting plate 202 is greater than 0. Two metal parts 203 are arranged on the first connecting plate 202, namely the first metal part and the second metal part. The first metal part is connected to the first pole ear 101, and the second metal part is connected to the second pole ear 104. At the same time, the first pole ear 101 and the second pole ear 104 are at the same end of the pole core assembly 1.

[0050] The second structure of the first connecting plate 202: includes a second connecting plate 201 and two first connecting plates 202, wherein one first connecting plate 202 is arranged at one end of the second connecting plate 201, and the other first connecting plate 202 is arranged at the other end of the second connecting plate 201, and each first connecting plate 202 is provided with a metal part 203, and the two metal parts 203 are respectively a first metal part and a second metal part, the first metal part is connected to the first pole ear 101, and the second metal part is connected to the second pole ear 104, and the first pole ear 101 and the second pole ear 104 are at both ends of the pole core assembly 1.

[0051] In the second embodiment, the number of the first connecting plates 202 is limited and is related to the positions of the first pole lug 101 and the second pole lug 104 in the pole core assembly 1. When the first pole lug 101 and the second pole lug 104 are at the same end of the pole core assembly 1, the number of the first connecting plates 202 is preferably one; when the first and the second pole lug 104 are not at the same end of the pole core assembly 1, the number of the first connecting plates 202 is preferably two.

[0052] The angle between the first connecting plate 202 and the second connecting plate 201 is greater than 0, that is, the second connecting plate 201 and the first connecting plate 202 are not on the same plane, so that the first metal part on the first connecting plate 202 is arranged in the first space and the second metal part is arranged in the second space.

[0053] In the second embodiment, preferably, the angle between the second connecting plate 201 and the first connecting plate 202 is 90±10°.

[0054] Because the second connecting plate 201 is placed between the two pole cores 103, and the first pole ear 101 and the second pole ear 104 are located at both ends of the pole core 103, the end of the first pole ear 101 away from the pole core assembly 1 is bent toward the pole core assembly 1, and a first space is formed between the first pole ear 101 and the pole core assembly 1, and the end of the second pole ear 104 away from the pole core assembly 1 is bent toward the pole core assembly 1, and a second space is formed between the second pole ear 104 and the pole core assembly 1. The first space is perpendicular to the plane of the second connecting plate 201, and the second space is perpendicular to the plane of the second connecting plate 201, which limits the angle between the second connecting plate 201 and the first connecting plate 202 to 90±10°, so that the first metal part on the first connecting plate 202 is placed in the first space, and the second metal part is placed in the second space.

[0055] In the second embodiment, more preferably, the included angle between the second connecting plate 201 and the first connecting plate 202 is 90±5°.

[0056] In the second embodiment, a second pole ear 104 is provided at one end of the pole core assembly 1 away from the first pole ear 101; a first connecting plate 202 is provided at each of the two ends of the second connecting plate 201, and each first connecting plate 202 is provided with the metal part 203, and the two metal parts 203 are defined as a first metal part and a second metal part, and the first metal part is arranged in the first space, and the second pole ear 104 is bent toward the inner direction of the pole core assembly 1 to form a second space between the pole core assembly 1, and the second metal part is arranged in the second space.

[0057] Specifically, a first connecting plate 202 is provided at both ends of the second connecting plate 201, a metal part 203 is provided on each first connecting plate 202, a first pole ear 101 is provided at one end of the pole core assembly 1, and a second pole ear 104 is provided at the end of the pole core assembly 1 away from the first pole ear 101, the first metal part is connected to the first pole ear 101, and the second pole ear 104 is connected to the second metal part.

[0058] In the second embodiment, the battery includes two top cover plates 3, namely a first top cover plate 301 and a second top cover plate 302, the first top cover plate 301 is provided with a first pole 3011, the second top cover plate 302 is provided with a second pole 3021, the first pole ear 101 is connected to the first pole 3011 on the side away from the first metal part, and the second pole ear 104 is connected to the second pole 3021 on the side away from the second metal part.

[0059] Specifically, the battery includes two top cover plates 3, and the housing 4 is a structure with openings 401 at both ends. The first top cover plate 301 is used to seal one of the openings 401, and the second top cover plate 302 is used to seal the other opening 401. The first metal member can prevent the first pole 3011 on the top cover plate 3 from being welded to the first pole tab 101 to prevent the pole core 103 near the position of the first pole tab 101 from being burned, and the second metal member can prevent the second pole 3021 on the top cover plate 3 from being welded to the second pole tab 104 to prevent the pole core 103 near the position of the second pole tab 104 from being burned.

[0060] In the second embodiment, a side of the second connecting plate 201 facing the pole core 103 is coated with a heat insulating material for heat insulating the two pole cores 103 .

[0061] The surface of the second connecting plate 201 is coated with a heat-insulating material to insulate the two pole cores 103 , thereby preventing one pole core 103 from heating up and transferring the heat to the other pole core 103 quickly during the battery charging and discharging process, thereby affecting the charging and discharging performance of the other pole core 103 .

[0062] Third embodiment

[0063] The third embodiment of the present application provides a secondary battery. The structure of the connector 2 in the battery is different from that in the first embodiment, but the rest is the same as that in the first embodiment, as described below.

[0064] In the third embodiment, the connecting member 2 includes at least one first connecting plate 202 and two third connecting plates 204, the metal member 203 is arranged on the first connecting plate 202, the first connecting plate 202 is arranged between the first pole ear 101 and the pole core assembly 1, the first connecting plate 202 includes a first end and a second end, the first end is connected to one end of one of the third connecting plates 204, and the second end is connected to one end of the other third connecting plate 204; the two third connecting plates 204 are respectively arranged on both sides of the pole core assembly 1.

[0065] The two third connecting plates 204 are respectively arranged on the sides of the two pole cores, and are used to provide internal support for the connecting member 2 when the pole lugs and poles are welded.

[0066] It should be noted that the installation position of the first connecting plate 202 and the installation position of the metal member 203 are the same as those in the first embodiment.

[0067] Fourth embodiment

[0068] like Figure 5 As shown, the fourth embodiment of the present application provides a secondary battery. The structure of the connector 2 in the battery is different from that in the second embodiment, and the rest is the same, as follows.

[0069] In the fourth embodiment, the connecting member 2 includes two first connecting plates 202 and two third connecting plates 204. The two first connecting plates 202 are arranged opposite to each other, and the two third connecting plates 204 are arranged opposite to each other. Metal parts 203 are arranged on the two first connecting plates 202. One end of the first connecting plate 202 is connected to one end of one of the third connecting plates 204, and the other end of the first connecting plate 202 is connected to one end of the other third connecting plate 204. Similarly, the two ends of the other first connecting plate 202 are also connected to one end of the two third connecting plates 204. The two first connecting plates 202 and the two third connecting plates 204 form a closed structure.

[0070] The arrangement position of the metal member 203 and the arrangement position of the first connecting plate 202 are the same as those of the second embodiment. The pole core assembly 1 includes two pole cores, and two third connecting plates 204 are respectively arranged on the sides of the two pole cores to provide internal support for the connecting member 2 when the pole lugs and poles are welded.

[0071] In the fourth embodiment, the connecting member 2 is a U-shaped structure. It can be understood that the structure of the connecting member 2 is different according to the different structures of the pole core assembly 1.

[0072] For the top cover plate 3 of the battery in the first embodiment and the second embodiment, a liquid injection hole and an explosion-proof valve are provided on the top cover plate 3. It should be noted that when there are two top cover plates 3 in a single battery, one of the top cover plates 3 can be provided with a liquid injection hole and an explosion-proof valve, and the other can be provided without a liquid injection hole and an explosion-proof valve.

[0073] On the other hand, the present application provides a secondary battery assembly process, comprising the following steps:

[0074] The pole core assembly 1 is provided with a first pole ear 101 and a second pole ear 104, and the connecting member 2 includes a first metal member and a second metal member. The first metal member is placed in the first space formed by bending the first pole ear 101 toward the inside of the pole core assembly 1, and the second metal member is placed in the second space formed by bending the second pole ear 104 toward the inside of the pole core assembly 1, and then pole ear glue is attached to both ends of the first pole ear 101 and the second pole ear 104 respectively;

[0075] Then, the pole core assembly 1 is placed into the shell, the top cover plate 3 is press-fitted, and a laser is used to perform laser welding from the top of the first pole 3011 on the top cover plate 3 from top to bottom, and the first pole 3011 is welded together with the first pole ear 101 and the first metal part, and / or a laser is used to perform laser welding from the top of the second pole 3021 on the top cover plate 3 from top to bottom, and the second pole 3021 is welded together with the second pole ear 104 and the second metal part;

[0076] Finally, the shell 4 and the top cover plate 3 are welded around the periphery.

[0077] Specifically, the first pole lug 101 and the second pole lug 104 are generally pole lug clusters composed of multiple pieces of foil. Before bending the first pole lug 101 and the second pole lug 104, the first pole lug 101 composed of multiple pole lug clusters can be pre-welded, and the second pole lug 104 composed of multiple pole lug clusters can be pre-welded; or the pole lug clusters are not pre-welded and are directly bent; this application does not make any limitation, and whether to pre-weld can be selected according to actual needs.

[0078] The two ends of the first pole tab 101 are pasted with pole tab glue, and the two ends of the second pole tab 104 are pasted with pole tab glue to prevent part of the foil in the pole tab cluster from being welded to the pole column, and to ensure that the foil in the pole tab cluster is welded to the pole column.

[0079] The pole core assembly 1 includes two pole cores 103, which are bonded together with a protective adhesive 102 to form the pole core assembly 1, and also protect the pole cores 103 from damage. It should be noted that the protective adhesive 102 can be applied before the first pole tab 101 or the second pole tab 104 is bent, or before the shelling process.

[0080] The top cover plate 3 is pressed to cover the opening 401 of the shell 4. The shell 4 and the top cover plate 3 are welded around the periphery to seal the opening 401 of the shell 4 to prevent battery leakage.

[0081] Compared with the prior art, the assembly process of the secondary battery provided in the present application directly performs laser welding from top to bottom above the first pole 3011 on the top cover plate 3 to weld the first pole 3011 with the first pole ear 101 and the first metal part together, and / or performs laser welding from top to bottom above the second pole 3021 on the top cover plate 3 to weld the second pole 3021 with the second pole ear 104 and the second metal part together; the welding process of the first pole ear 101 and the positive electrode connecting plate and the welding process of the second pole ear 104 and the negative electrode connecting plate are reduced, the process is reduced, and the battery cost is reduced; at the same time, the absence of the connecting plate reduces the space occupied by the bending of the connecting plate, increases the volume of the pole core assembly 1, improves the utilization rate of the internal space of the battery, and improves the energy density of the battery; at the same time, the use of the connecting plate is reduced, and the cost of the battery is also reduced.

[0082] It should be noted that the polarities of the first electrode tab 101 and the second electrode tab 104 are different. For example, when the first electrode tab 101 is a positive electrode tab, the second electrode tab 104 is a negative electrode tab. When the first electrode tab 101 is a negative electrode tab, the first electrode tab 104 is a positive electrode tab.

[0083] The specific embodiments of the present invention will be further explained below through examples, but it does not mean that the protection scope of the present invention is limited to the scope described in the examples.

[0084] Example 1

[0085] This embodiment provides an assembly process of the secondary battery disclosed in this application.

[0086] The pole core assembly 1 includes two pole cores 103, and the connecting member 2 includes a first connecting plate 202, on which a first metal member and a second metal member are arranged. Each pole core 103 is provided with a first pole lug 101 and a second pole lug 104, and the first pole lug 101 and the second pole lug 104 are at the same end of the pole core 103. The top cover plate 3 is provided with a first pole column 3011 and a second pole column 3021.

[0087] S1 pre-welding: pre-welding the first pole tab 101 and the second pole tab 104 on each pole core 103;

[0088] S2 pole core 103 is assembled with connector 2: two pole cores 103 are stacked together, and the first pole ears 101 of the two pole cores 103 are arranged opposite to each other, and the second pole ears 104 are also arranged opposite to each other. The first connecting plate 202 is placed between the two first pole ears 101, and also between the two second pole ears 104, and the first metal part and the second metal part on the first connecting plate 202 are placed toward the pole core 103. Then, the two first pole ears 101 are bent toward the inside of the pole core assembly 1 to form a first space, and the first metal part is located in the first space. The two second pole ears 104 are bent toward the inside of the pole core assembly 1 to form a second space, and the second metal part is located in the second space. Then, pole ear glue is applied to both ends of the two first pole ears 101 to bond the two first pole ears 101 together; similarly, pole ear glue is applied to both ends of the two second pole ears 104 to bond the two second pole ears 104 together.

[0089] S3: Paste protective glue 102 on the pole core assembly 1: Paste protective glue 102 on the outer surfaces of the two pole cores 103.

[0090] S4: Entering the shell;

[0091] S5: Press-fit the top cover plate 3;

[0092] S6: Laser welding: Laser welding is performed from top to bottom above the first pole 3011 on the top cover plate 3 to weld the first pole 3011, the first pole ear 101 and the first metal part together. Laser welding is performed from top to bottom above the second pole 3021 on the top cover plate 3 to weld the second pole 3021, the second pole ear 104 and the second metal part together.

[0093] The shell 4 and the periphery of the top cover plate 3 are laser welded.

[0094] Example 2

[0095] The pole core assembly 1 includes two pole cores 103, and the connecting member 2 includes a second connecting plate 201, and a first connecting plate 202 is respectively provided at both ends of the second connecting plate 201. The two first connecting plates 202 are defined as a positive second connecting plate 201 and a negative first connecting plate 202. A first metal part is provided on the positive second connecting plate 201, and a second metal part is provided on the negative first connecting plate 202. Each pole core 103 is provided with a first pole ear 101 and a second pole ear 104, and the first pole ear 101 and the second pole ear 104 are at opposite ends of the pole core 103.

[0096] The battery includes two top cover plates 3 , which are defined as a first top cover plate 301 and a second top cover plate 302 . A first pole 3011 is disposed on the first top cover plate 301 , and a second pole 3021 is disposed on the second top cover plate 302 .

[0097] S1 pre-welding: pre-welding the first pole tab 101 and the second pole tab 104 on each pole core 103;

[0098] The S2 pole core 103 is assembled with the connecting piece 2 : the two pole cores 103 are stacked together, the second connecting plate 201 is placed between the two pole cores 103 , and the protective glue 102 is attached to the outer surfaces of the two pole cores 103 .

[0099] The first pole tabs 101 of the two pole cores 103 are arranged oppositely, and the second pole tabs 104 are also arranged oppositely. The positive first connecting plate 202 is placed between the two first pole tabs 101, and the negative first connecting plate 202 is placed between the two second pole tabs 104, and the first metal part and the second metal part are both facing the pole core 103.

[0100] Then, the two first pole tabs 101 are bent toward the inside of the pole core assembly 1 to form a first space, and the first metal part is located in the first space. The two second pole tabs 104 are bent toward the inside of the pole core assembly 1 to form a second space, and the second metal part is located in the second space. Then, pole tab glue is applied to both ends of the two first pole tabs 101 to bond the two first pole tabs 101 together; similarly, pole tab glue is applied to both ends of the two second pole tabs 104 to bond the two second pole tabs 104 together.

[0101] S3: Enter the shell;

[0102] S4: Press-fit the top cover plate 3;

[0103] S5: Laser welding: Laser welding is performed from top to bottom above the first pole 3011 on the top cover plate 3 to weld the first pole 3011, the first pole ear 101 and the first metal part together. Laser welding is performed from top to bottom above the second pole 3021 on the top cover plate 3 to weld the second pole 3021, the second pole ear 104 and the second metal part together.

[0104] The shell 4 and the periphery of the top cover plate 3 are laser welded.

[0105] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A secondary battery, characterized in that: The invention comprises at least one top cover plate, at least one connecting member and a pole core assembly, wherein at least one end of the pole core assembly is provided with a first pole ear, an end of the first pole ear away from the pole core assembly is bent toward the direction of the pole core assembly, and a first space is formed between the first pole ear and the pole core assembly; the top cover plate is provided on the side of the first pole ear away from the pole core assembly, a pole column is provided on the top cover plate, and the first pole ear is welded to the pole column; the connecting member is provided on the side of the top cover plate facing the pole core assembly, the connecting member comprises at least one metal member, the metal member is provided in the first space, and a side of the first pole ear away from the pole column is connected to the metal member; the connecting member further comprises a first connecting plate, the metal member is provided on the first connecting plate, and the first connecting plate is provided between the first pole ear and the pole core assembly; The connecting member also includes a second connecting plate, the first connecting plate is arranged at at least one end of the second connecting plate, and the angle between the first connecting plate and the second connecting plate is greater than 0; the pole core assembly includes at least two pole cores, the second connecting plate is arranged between the two pole cores, and the first connecting plate is arranged on the side of the pole core facing the top cover plate.

2. The secondary battery according to claim 1, characterized in that: Two metal parts are arranged on the first connecting plate, and the two metal parts are respectively a first metal part and a second metal part. A second pole ear is also arranged at one end of the pole core assembly, and the second pole ear and the first pole ear are arranged at the same end of the pole core assembly. The first metal part is arranged in the first space, and the end of the second pole ear away from the pole core assembly is bent toward the pole core assembly, and a second space is formed between the second pole ear and the pole core assembly. The second metal part is arranged in the second space, and the second metal part is connected to the second pole ear; a first pole column and a second pole column are arranged on the top cover plate, and the side of the first pole ear facing away from the first metal part is connected to the first pole column, and the side of the second pole ear facing away from the second metal part is connected to the second pole column.

3. The secondary battery according to claim 1, characterized in that: A second pole ear is provided at one end of the pole core assembly away from the first pole ear; one first connecting plate is provided at each of the two ends of the second connecting plate, each of the first connecting plates is provided with the metal part, the two metal parts are respectively a first metal part and a second metal part, the first metal part is arranged in the first space, the end of the second pole ear away from the pole core assembly is bent toward the direction of the pole core assembly, a second space is formed between the second pole ear and the pole core assembly, the second metal part is arranged in the second space, and the second metal part is connected to the second pole ear.

4. The secondary battery according to claim 1, characterized in that: The included angle between the second connecting plate and the first connecting plate is 90±10°; a heat insulation layer is coated on one side of the second connecting plate facing the pole core, which is used for heat insulation of the two pole cores.

5. The secondary battery according to claim 1, characterized in that: The top cover plate is also provided with a mounting hole, an insulating member and a pole cap, the pole includes a column portion and a connecting portion, the column portion passes through the mounting hole, the connecting portion is connected to a side of the top cover plate facing the pole core assembly, the insulating member is arranged on a side of the connecting portion facing the pole core assembly, a channel is arranged in the column portion, the pole cap is arranged in the channel, and the pole cap is connected to the column portion.

6. The secondary battery according to claim 1, characterized in that: A pole lug glue is provided on a side of the first pole lug facing the top cover plate, and the pole lug glue is provided at two ends of the first pole lug.

7. A secondary battery, characterized in that: The invention comprises at least one top cover plate, at least one connecting member and a pole core assembly, wherein at least one end of the pole core assembly is provided with a first pole ear, an end of the first pole ear away from the pole core assembly is bent toward the direction of the pole core assembly, and a first space is formed between the first pole ear and the pole core assembly; the top cover plate is provided on the side of the first pole ear away from the pole core assembly, a pole column is provided on the top cover plate, and the first pole ear is welded to the pole column; the connecting member is provided on the side of the top cover plate facing the pole core assembly, the connecting member comprises at least one metal member, the metal member is provided in the first space, and a side of the first pole ear away from the pole column is connected to the metal member; the connecting member further comprises a first connecting plate, the metal member is provided on the first connecting plate, and the first connecting plate is provided between the first pole ear and the pole core assembly; The connecting member also includes two third connecting plates, the first connecting plate includes a first end and a second end, the first end is connected to one end of one of the third connecting plates, and the second end is connected to one end of the other third connecting plate; the two third connecting plates are arranged opposite to each other, and the two third connecting plates are respectively arranged on both sides of the pole core assembly.

8. An assembly process for a secondary battery according to any one of claims 1 to 7, characterized in that: The following steps are involved: The pole core assembly is provided with a first pole ear and a second pole ear, and the connecting member includes a first metal member and a second metal member, the first metal member is placed in the first space formed by bending the first pole ear toward the inside of the pole core assembly, and the second metal member is placed in the second space formed by bending the second pole ear toward the inside of the pole core assembly, and then pole ear glue is respectively attached to both ends of the first pole ear and the second pole ear; Then, the pole core assembly is placed in the shell and the top cover plate is pressed, and a laser is used to perform laser welding from top to bottom above the first pole on the top cover plate to weld the first pole, the first pole lug and the first metal part together, and a laser is used to perform laser welding from top to bottom above the second pole on the top cover plate to weld the second pole, the second pole lug and the second metal part together; Finally, the shell and the top cover are welded around the perimeter.

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