CN121663117A - Battery cell, battery pack and vehicle - Google Patents

Abstract

The application discloses a battery cell, a battery pack and a vehicle, wherein a connecting piece is electrically connected to a positive pole or a negative pole in the battery cell, the two battery cells can be directly and electrically connected through the connecting piece on the positive pole or the negative pole, and a bus bar and a wire harness isolation plate are not required to be arranged, so that occupation of space in the height direction of the battery cell can be reduced, the height of the battery cell is increased, and the energy density of the battery pack is increased. In addition, for the battery pack adopting the battery core top cooling scheme, the cooling capacity of the heat dissipation part can reach the battery core quickly, and the efficiency of the heat dissipation part on cooling the battery core is improved.

Description

Battery cell, battery pack and vehicle

Technical Field

The application relates to the field of batteries, in particular to a battery cell, a battery pack and a vehicle.

Background

Currently, a battery pack is generally composed of a plurality of battery cells 100', each battery cell 100' has a case, a pole group, a positive pole and a negative pole, the pole group is encapsulated inside the case, and the pole group is electrically connected with an external circuit through the pole group. The series-parallel connection between the battery cells 100 'is generally achieved by riveting rivet plates (not shown in fig. 1) to the outer ends of the two poles at the housing, welding the rivet plates with the bus bars 300', and implementing the series-parallel connection between the battery cells 100 'through the bus bars 300' to form a battery pack.

Referring to fig. 1, it can be seen that one battery pack has a plurality of battery cells 100', and the poles of adjacent battery cells 100' are welded by bus bars 300', so that the number of the battery cells 100' is relatively large, and the number of the bus bars 300' is relatively large. For convenience of assembly, the current sampling structure of the flexible printed circuit board (Flexible Printed Circuit, FPC) 400' and the bus bar 300' are pre-mounted on the harness isolation board 200' to form a cell connection system, and then welded with the poles of the cell 100', which is also a common structure for connecting the cell 100' in the art.

The cell connection system needs to occupy a larger cell height space, which affects the height of the cell to a certain extent and further affects the energy density of the battery pack.

Disclosure of Invention

The application aims to provide a battery cell which can improve the energy density of a battery pack and is simple to assemble. Another object of the present application is to provide a battery pack and a vehicle having the above-described battery cell.

The application provides a battery cell, comprising:

A housing;

a positive electrode post and a negative electrode post, both having a first portion located outside the housing;

And each first part is electrically connected with the connecting piece, and the two electric cores are directly electrically connected through the connecting pieces arranged on the two electric cores.

Compared with the prior art that the bus bar is arranged to realize the electric connection between the electrode posts of the two electric cores, the positive electrode post or the negative electrode post is electrically connected with the connecting piece, the two electric cores can be directly and electrically connected through the connecting piece on the two electric cores, and the bus bar and the wire harness isolation plate are not required to be arranged, so that occupation of space in the height direction of the electric cores can be reduced, the height of the electric cores is increased, and the energy density of the battery pack is increased. And when the battery core is assembled in place, the positions of the connecting pieces are also determined at the same time, and only two connecting pieces with an electric connection relationship are required to be fixed, so that the assembly is simple, and the production cost is relatively low.

In addition, for the battery pack adopting the battery cell top cooling scheme, the cooling capacity of the heat dissipation part can reach the battery cell rapidly, and the efficiency of the heat dissipation part on cooling the battery cell is improved.

In one example, the connecting piece is provided with a contact part, and the contact parts of the two connecting pieces are abutted to realize electrical connection.

In an example, the contact portion is disposed on a first surface or a second surface of the connecting member, the contact portions of the two directly electrically connected connecting members are oppositely lapped and abutted, and the first surface and the second surface are both arranged along a height direction of the electric core.

In one example, the first surface or the second surface has a concave surface, the contact portion is at least a partial area of the concave surface, the concave surface of one of the two directly electrically connected connectors is located on the first surface, and the concave surface of the other connector is located on the second surface.

In one example, the connection on the positive post is defined as a first connection, the connection on the negative post is defined as a second connection, the concave surface of the first connection is located on the first surface of the first connection, and the concave surface on the second connection is located on the second surface of the second connection.

In one example, the contact portion is located at an end face of the connector remote from the first portion.

In one example, the end of the connector remote from the first portion is provided with a socket or plug to enable direct electrical connection of the two connectors.

In one example, the recessed surface is configured to extend to and support the length of the housing adjacent the cell.

In one example, the connection member extends along the stacking direction of the battery cells, or the extending direction of the connection member forms an included angle with the stacking direction of the battery cells.

In addition, the embodiment of the application also provides a battery pack, which comprises a plurality of the electric cores, wherein each electric core is electrically connected through each connecting piece.

Furthermore, the embodiment of the application also provides a vehicle, which comprises a vehicle body, wherein the battery cell of any one of the above-mentioned battery packs is arranged on the vehicle body, or/and the battery pack of the above-mentioned battery packs is/are arranged on the vehicle body.

The battery pack and the vehicle in the embodiment of the application have the above-mentioned battery cells, so that the battery pack and the vehicle also have the above-mentioned technical effects of the battery cells.

Drawings

Fig. 1 is an exploded view of the internal structure of a current battery pack;

FIG. 2 is a schematic diagram of the major components of a battery pack according to one embodiment of the present application;

FIG. 3 is a schematic diagram of a cell in an embodiment of the present application;

fig. 4 is a schematic diagram of adjacent cells arranged along a stacking direction in an unassembled state according to an embodiment of the present application;

FIG. 5 is a C-C end view of the structure of FIG. 4;

FIG. 6 is an enlarged schematic view of a partial position of FIG. 5A;

FIG. 7 is an enlarged schematic view of a portion of FIG. 2;

Fig. 8 is a schematic diagram of two battery cells in an assembled state according to another embodiment of the application;

fig. 9 is a D-D end view of fig. 8.

Wherein, the one-to-one correspondence between the reference numerals and the component names in fig. 1 is as follows:

100 'battery core, 200' wire harness isolation board, 300 'bus bar, 400' flexible printed circuit board;

wherein, the one-to-one correspondence between the reference numerals and the component names in fig. 2 to 9 is as follows:

100 cells, 101 first cells, 102 second cells;

1 shell, 11 upper cover plate, 11a explosion-proof valve, 2 pole group, 3 positive pole, 31 first part, 32 second part, 4 negative pole, 5 first connecting piece, 51 first concave surface, 52 first end surface, 6 second connecting piece, 61 second concave surface and 63 second end surface.

Detailed Description

The inventor of the present application has made a great deal of research on the technical problem that the battery cell connection system occupies a larger battery cell height, and found that the main reason for the technical problem is that each busbar needs to be fixed on a harness isolation plate in advance and then welded with a riveting plate, and the thickness of the assembly formed by the busbar and the harness isolation plate is relatively larger.

In addition to the above technical problems, the bus bar and the wire harness insulation board are high in production cost and complex in assembly.

In addition, the battery cell emits a large amount of heat during operation, and the battery cell needs to be cooled in time. Part of the battery pack can adopt a battery cell top cooling scheme, namely, a heat dissipation part is arranged at the top of the battery cell. When the battery cell is cooled by adopting the mode, the cooling capacity of the heat dissipation part can reach the battery cell only through the bus bar and the wire harness isolation plate, and the bus bar and the wire harness isolation plate can generate heat conduction thermal resistance, so that the cooling efficiency of the heat dissipation part to the battery cell is reduced.

Therefore, how to overcome at least one of the above-mentioned drawbacks is a technical problem that a person skilled in the art needs to solve.

The technical scheme and the technical effect are introduced by taking the example that each battery cell is positively arranged, namely, the lugs of each battery cell are positioned at the top of the battery cell, and the technical scheme disclosed by the application is also applicable to battery packs with inverted or laterally arranged battery cells.

Referring to fig. 2, fig. 2 is a schematic structural diagram of major components of a battery pack according to an embodiment of the application.

The embodiment of the application provides a battery pack, which comprises a box body (not shown in fig. 2) and a plurality of battery cells positioned in the box body, wherein the battery cells are stacked along the x direction to form a row of battery cell assemblies, and the box body can be internally provided with a row of battery cell assemblies, and at least two rows of battery cell assemblies can be arranged along the y direction. All the electric cores are connected in series or/and in parallel according to rules to form a power supply. Fig. 2 shows an example in which all the cells are connected in series in order, and the connection method of each cell in the battery pack is not limited to the electrical connection method described in the present application.

As will be understood with reference to fig. 3, 4,5 and 6, fig. 3 is a schematic structural diagram of a cell according to an embodiment of the present application, fig. 4 is a schematic diagram of adjacent cells arranged along a stacking direction in an unassembled state according to an embodiment of the present application, fig. 5 is a cross-sectional view of C-C in the structure shown in fig. 4, and fig. 6 is an enlarged schematic diagram of a partial position at a in fig. 5. The cell structures in fig. 4 and fig. 5 are substantially the same, and for the sake of brevity of description of the technical solution, the present application defines adjacent cells as a first cell and a second cell, respectively.

In the embodiment of the present application, one of the battery cells 100 includes a housing 1 and a pole group 2 enclosed in the housing 1, wherein the housing 1 has an opening at an upper end, and an upper cover 11 is disposed at the opening, and the upper cover 11 is generally mounted at the opening of the housing 1 after the pole group 2 is mounted in the housing 1. The electrode group 2 is used for storing electric energy, and the electrode group 2 is provided with two electrode lugs, namely a positive electrode lug and a negative electrode lug. For the safety of the battery cell 100, an explosion-proof valve 11a is provided on the upper cover plate 11.

The cell 100 also has a positive terminal 3 and a negative terminal 4, the positive terminal 3 and the negative terminal 4 each having a second portion 32 located inside the housing 1 and a first portion 31 located outside the housing 1, the first portion 31 typically passing through the upper cover 11 to be located outside the housing 1. The positive tab is electrically connected to the second portion 32 of the positive post 3 and the negative tab is electrically connected to the second portion 32 of the negative post 4, so that the electric energy of the electrode group 2 can be transmitted to the outside of the case 1 through the positive post 3 and the negative post 4. The positive electrode post 3 is fixedly and electrically connected with the positive electrode lug, the negative electrode post 4 and the negative electrode lug, and the specific fixing mode can adopt laser welding, brazing, ultrasonic welding and the like.

The embodiment of the present application shows a specific example that the positive electrode post 3 and the negative electrode post 4 are located at the top of the battery cell 100, and generally, two mounting through holes are provided on the upper cover plate 11, which are respectively opposite to the positive electrode post 3 and the negative electrode post 4, and the first portion 31 of the positive electrode post 3 and the first portion 31 of the negative electrode post 4 respectively penetrate through the two mounting through holes. The clearance between the positive pole 3 or the negative pole 4 and the corresponding installation through hole needs to be sealed by using a sealing part, so that the air leakage is avoided, and the influence of the environment in the box body on the work of the pole group 2 in the shell 1 can be avoided. The sealing component can be a sealing ring, and the sealing ring is sleeved on the positive pole 3 and the negative pole 4. The sealing ring can seal the gap between the installation through hole of the upper cover plate 11 and the corresponding pole. The sealing ring can be an elastic sealing ring such as a fluororubber sealing ring, and can be a hard material sealing ring, such as a ceramic sealing ring.

Although specific structures such as the seal ring and the tab are not shown in the drawings, the understanding and implementation of the technical content of the present application described above by those skilled in the art are not hindered.

The shape of the positive electrode post 3 and the negative electrode post 4 may be determined according to a specific product, for example, the positive electrode post 3 and the negative electrode post 4 may be cylindrical, but may be other shapes, for example, polygonal shapes.

In the embodiment of the present application, the battery cell 100 further includes a connecting member, and each first portion 31 is electrically connected to the connecting member, that is, the positive electrode post 3 is electrically connected to the connecting member, the negative electrode post 4 is also electrically connected to the connecting member, and the connecting member and the electrode post electrically connected thereto may be integrally formed. The connecting piece and the pole column which is electrically connected with the connecting piece can be fixedly connected, namely the connecting piece and the pole column which is electrically connected with the connecting piece are of a split structure, and the connecting piece and the pole column are fixed into a whole through other process means. The connecting piece and the pole post can be fixedly connected in a riveting, welding or screwing fixing or interference fixing mode. For example, the first portion 31 of the positive electrode tab 3 or the negative electrode tab 4 is provided with a caulking groove, and the connecting member is caulking-connected inside the caulking groove. The riveting process is relatively simple.

In the embodiment of the application, the connecting piece also has good conductivity, and the materials of the positive electrode column 3, the negative electrode column 4 and the connecting piece can be the same or different. The materials of the positive electrode post 3, the negative electrode post 4, and the connecting member may be single-component materials, such as copper materials, aluminum materials, and the like, having good conductivity, or composite materials composed of different components, such as composite materials formed of materials having good conductivity, such as copper aluminum, and the like, as long as good conductivity is achieved.

In the embodiment of the present application, the positive electrode post 3 or the negative electrode post 4 are both provided with a connecting piece, and one electric core 100 can be directly and electrically connected with a corresponding connecting piece on the other electric core 100 through the connecting piece on the connecting piece. For simplicity of description of the technical solution, the present application defines the connection piece on the positive electrode post 3 as the first connection piece 5, and the connection piece on the negative electrode post 4 as the second connection piece 6. Referring to fig. 5, the first connection member 5 on the positive electrode post 3 of the first cell 101 is directly electrically connected to the second connection member 6 on the negative electrode post 4 of the second cell 102. Typically, the two connectors are directly connected electrically.

Compared with the prior art that the bus bar is arranged to realize the electric connection between the poles of the two electric cores 100, in the embodiment of the application, the positive pole 3 or the negative pole 4 are electrically connected with the connecting pieces, the two connecting pieces of the two electric cores 100 can be directly electrically connected to realize the electric connection between the two electric cores 100, and the bus bar and the wire harness isolation plate are not required to be arranged, so that the occupation of the space of the electric cores 100 in the height direction can be reduced, the height of the electric cores 100 can be increased, and the energy density of the battery pack can be increased. In addition, when the battery cell 100 is assembled in place, the positions of the connecting pieces are also determined at the same time, and only two connecting pieces with an electric connection relationship are required to be fixed, so that the assembly is simple, and the production cost is relatively low.

In addition, for the battery pack adopting the top cooling scheme of the battery cell 100, the cooling capacity of the heat dissipation part can reach the battery cell 100 quickly, and the cooling efficiency of the heat dissipation part on the battery cell 100 is improved.

In the embodiment of the application, the connecting pieces are provided with the contact parts, the two connecting pieces are abutted against each other through the contact parts to realize electric connection, the connecting pieces are in contact electric connection through the contact parts, the contact area is relatively large, and the electric connection reliability is relatively high. In a specific example, the connection pieces with connection relation in the two battery cells 100 can realize the electrical connection of the two battery cells by welding, and the welding fixing reliability is higher. Taking fig. 4 and 5 as an example, the first connection piece 5 on the positive electrode post 3 of the first cell 101 is connected with the second connection piece 6 on the negative electrode post 4 of the second cell 102 by welding. In the embodiment, the two connecting pieces are fixed through welding, the process is simple, and the fixing is reliable.

In one embodiment, the contact is disposed on the first surface or the second surface of the connector, and the first surface and the second surface are both arranged along the height direction of the cell 100, and when two directly electrically connected connectors are welded, the contact of the two connectors is welded in a lap joint manner. As will be understood from fig. 5 and fig. 6, the contact portion of the first connection member 5 on the positive electrode post 3 of the first cell 101 is located on the first surface, and the contact portion of the second connection member 6 on the negative electrode post 4 of the second cell 102 is located on the second surface. Wherein the first surface is the surface of the connector facing upwards (the surface facing away from the side of the housing 1) and the second surface is the surface of the connector facing downwards (the surface facing towards the side of the housing 1). Of course, it is also possible that the contact portion of the first connection member 5 on the positive electrode post 3 is located on the second surface, and the contact portion of the second connection member 6 on the negative electrode post 4 is located on the first surface.

In this embodiment, the two connector portions electrically connected directly are stacked to be welded to form a whole, and the bonding reliability is high. The length L1 of the contact portion can be reasonably selected according to the reliability of the welding fixation.

After the corresponding connection pieces of the first battery cell 101 and the second battery cell 102 are welded, in order to reduce the height of the welding position as much as possible, the following arrangement is further performed in the embodiment of the present application.

In the embodiment of the application, the first surface or the second surface has a concave surface, and the contact portion is at least a partial area of the concave surface, that is, the contact portion may be the whole concave surface or a partial concave surface. The concave surface of one of the two directly electrically connected connecting pieces is positioned on the first surface, and the concave surface of the other connecting piece is positioned on the second surface. For simplicity of description of the technical solution, the present application defines the concave surface on the first connection member 5 as the first concave surface 51, and the concave surface on the second connection member 6 as the second concave surface 61, as shown in fig. 6, the depth H1 of the concave surface 51 on the first connection member 5 on the positive electrode post 3 of the first cell 101 is substantially equal to the depth H2 of the concave surface 61 of the second connection member 6 on the negative electrode post 4 of the second cell 102, so that the thickness of the welding position does not increase after the first connection member 5 of the first cell 101 and the second connection member 6 of the second cell 102 are welded.

In the embodiment of the present application, the concave surface 51 of the first connecting member 5 is located on the first surface of the first connecting member 5, and the concave surface 61 of the second connecting member 6 is located on the second surface of the second connecting member 6. Therefore, the positive pole 3 and the negative pole 4 of the battery cell 100 can be rapidly distinguished through different arrangement positions of the concave surfaces, and the battery cell 100 is prevented from being assembled wrongly.

In each of the above embodiments, the connecting member extends in the radial direction of the positive electrode column 3 or the negative electrode column 4, and specifically, the length of the recessed surface on the connecting member is configured to be capable of extending to and supporting the length on the case of the adjacent cell. As can be seen from fig. 5 and 6, the recess 51 of the first connection piece 5 of the first cell 101 is partially located above the housing 1of the second cell and can be supported directly or indirectly on the housing 1of the second cell. The recess 61 of the second connection element 6 of the second cell 102 also extends partially above the housing 1of the first cell and can be supported on the housing 1of the first cell 101. When the battery is installed in this way, the second connecting piece 6 in the second battery cell 102 can extend to the upper side of the shell 1of the first battery cell 101, the shell 1of the first battery cell 101 can support the end part of the second connecting piece 6, likewise, the first connecting piece 5 of the first battery cell 101 can extend to the upper side of the shell 1of the second battery cell 102, and the shell 1of the second battery cell 102 can support the end part of the first connecting piece 5. Thus, the shell 1 can play a certain supporting role on the two connected connecting pieces, and is beneficial to improving the overall strength. Of course, the support between the connector and the housing may be an insulating support, and a layer of insulating material may be further disposed therebetween to improve insulating properties.

In another embodiment, the first and second connection members 5, 6 may be end-welded, i.e. the contact portions are located on the end surfaces of the connection members. The welding between the first connection member 5 on the positive electrode post 3 of the first cell 101 and the second connection member 6 on the negative electrode post 4 of the second cell 102 may also be performed by fixing, by welding, the end faces of the first connection member 5 and the second connection member 6 extending opposite to each other, specifically, the first connection member 5 has a first end face 52, the second connection member 6 has a second end face 62, the first end face 52 and the second end face 62 are substantially vertical faces, the first end face 52 and the second end face 62 are attached opposite to each other, and the two are fixedly connected by welding. The first connecting member 5 and the second connecting member 6 in this embodiment are relatively simple in structure.

Of course, the first connecting piece 5 and the second connecting piece 6 may have other structures, as long as the welding of the two is reliable.

In another embodiment, the end of the connector remote from the first portion 31 is provided with a socket or spigot. For example, one of the opposite ends of the first connection member 5 on the positive electrode post 3 of the first cell 101 and the second connection member 6 on the negative electrode post 4 of the second cell 102 is provided with a jack, and the other is provided with a plug body, and the plug body can be inserted into the jack. The number of the jacks may be one or a plurality of jacks. Accordingly, the shape and number of the plug bodies are determined according to the shape and number of the insertion holes. The plug body can be in the form of a pin or a plug block.

In the embodiment of the present application, the connection members extend along the stacking direction x of the cells 100, as shown in fig. 2 and 7, in the same cell 100 assembly, the connection members connecting adjacent cells 100 extend along the x direction.

Of course, the extending direction of the connecting member may also have an included angle with the stacking direction of the battery cells 100, please refer to the first connecting member 5 and the second connecting member 6, which are directly and electrically connected at the position B circled in fig. 7, and the two connecting members connected between the two battery cell 100 assemblies extend along the y direction, and the y direction is approximately perpendicular to the x direction. Of course, according to the different arrangement positions of the two rows of the battery cells 100, the extending direction of the extending section may be different from the x direction, and the included angle between the extending section and the x direction is an acute angle or an obtuse angle.

The connecting piece in the embodiment of the application can be a plate body with a preset thickness, and has a simple structure. Of course, the connection element may be a column or other shaped conductor.

The embodiment of the application also provides a vehicle, which comprises a vehicle body, wherein the battery cell 100 of any embodiment or/and the battery pack is arranged on the vehicle body.

The battery pack and the vehicle in the embodiment of the application have the above-mentioned battery cell 100, so the battery pack and the vehicle also have the above-mentioned technical effects of the battery cell 100.

For other structures of the battery pack, please refer to the current technology, the present application will not be described in detail.

In the description of embodiments of the present application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

In the embodiment of the application, "and/or" is merely an association relationship describing the association object, and indicates that three relationships may exist, for example, a and/or B may indicate that a exists alone, and a and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

The principles and embodiments of the present application have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the method of the present application and its core ideas. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the application can be made without departing from the principles of the application and these modifications and adaptations are intended to be within the scope of the application as defined in the following claims.

Claims (11)

1. A kind of electric core, characterized by comprising the following steps:

A housing;

a positive electrode post and a negative electrode post, both having a first portion located outside the housing;

And each first part is electrically connected with the connecting piece, and the two electric cores are directly electrically connected through the connecting pieces arranged on the two electric cores.

2. The cell of claim 1, wherein the connector is provided with contact portions, the contact portions of two connectors abutting against to achieve electrical connection.

3. The cell of claim 2, wherein the contact portion is disposed on a first surface or a second surface of the connection member, the contact portions of the two directly electrically connected connection members are oppositely overlapped and abutted, and the first surface and the second surface are both arranged along a height direction of the cell.

4. A cell according to claim 3, wherein the first surface or the second surface has a concave surface, the contact is at least a partial region of the concave surface, the concave surface of one of the two directly electrically connected connectors is located on the first surface, and the concave surface of the other is located on the second surface.

5. The cell of claim 4, wherein the connector on the positive post is defined as a first connector and the connector on the negative post is defined as a second connector, the recessed surface of the first connector being located on a first surface of the first connector and the recessed surface of the second connector being located on a second surface of the second connector.

6. The cell of claim 4 or 5, wherein the length of the recessed face is configured to extend to and support the length on the housing of an adjacent cell.

7. The cell of claim 2, wherein the contact is located at an end face of the connector remote from the first portion.

8. The cell of claim 1, wherein an end of the connector remote from the first portion is provided with a socket or plug to enable direct electrical connection of the two connectors.

9. The cell according to any one of claims 1 to 5, 7 and 8, wherein the connection member extends in a stacking direction of the cells or the extending direction of the connection member forms an angle with the stacking direction of the cells.

10. A battery pack comprising a plurality of cells according to any one of claims 1 to 9, each of the cells being electrically connected by each of the connectors.

11. A vehicle comprising a body, wherein the body is provided with the battery cell according to any one of claims 1 to 9, or/and the battery pack according to claim 10.