CN218769948U

CN218769948U - Bipolar battery

Info

Publication number: CN218769948U
Application number: CN202220954616.2U
Authority: CN
Inventors: 曾士哲
Original assignee: Weilai Automobile Technology Anhui Co Ltd
Current assignee: Weilai Automobile Technology Anhui Co Ltd
Priority date: 2022-04-24
Filing date: 2022-04-24
Publication date: 2023-03-28
Anticipated expiration: 2032-04-24

Abstract

The application discloses a bipolar battery, which includes: a plurality of electrochemical cells, adjacent two of the plurality of electrochemical cells being connected in series; and a plurality of seals arranged circumferentially around the plurality of electrochemical cells, at least one seal of the plurality of seals arranged with an injection and drain structure in the circumferential direction configured to allow electrolyte to flow into the electrochemical cells via the seal or to allow gases in the electrochemical cells to exit via the seal. The present application solves both the problems of electrolyte injection and formation gas venting using one structure by introducing an injection and venting structure at the seal for both the injection of electrolyte and the formation gas venting.

Description

Bipolar battery

Technical Field

The application relates to the field of storage batteries, in particular to a bipolar battery.

Background

The lithium ion battery is one of ideal power sources of the electric automobile, and with the rapid development of the new energy automobile market, the material system, the structural design and the process technology of the lithium ion battery are also rapidly updated and upgraded. In order to meet the power output of the electric automobile, a battery system needs to combine dozens or hundreds of single battery cells in series and parallel, so as to obtain the required high voltage and high capacity. The single battery cells are connected in series and in parallel through the external connecting piece, so that the energy density of the battery system is reduced, and the power density of the battery system is reduced.

The bipolar battery employs a design in which a plurality of battery cells are stacked together with bipolar plates connecting the battery cells in series. Through realizing establishing ties in that the battery is inside, not only improved the voltage of monomer electricity core, reduced unnecessary spare part simultaneously, promoted battery system's energy density and power density. Because ions between adjacent battery units in the bipolar battery do not flow, the liquid injection mode and the gas exhaust mode of the lithium battery with the traditional internal parallel structure are not suitable for the bipolar battery.

SUMMERY OF THE UTILITY MODEL

One aspect of the present application is directed to a bipolar battery having an electrolyte injection and venting configuration suitable for its internal cell configuration.

The bipolar battery comprises a first end plate; a second end plate opposite the first end plate; a plurality of electrochemical cells stacked between the first end plate and the second end plate, adjacent two of the plurality of electrochemical cells being connected in series; and a plurality of seals arranged circumferentially around the plurality of electrochemical cells, at least one seal of the plurality of seals arranged with an injection and drain structure in the circumferential direction configured to allow electrolyte to flow into the electrochemical cells via the seal or to allow gases in the electrochemical cells to exit via the seal.

In one embodiment of a bipolar battery, the fill and drain structure includes an opening disposed on the seal and a flow channel predisposed on the seal in fluid communication with the opening.

In one embodiment of a bipolar battery, one end of the flow channel leading to the electrochemical cell is connected to an existing electrolyte flow path within the bipolar battery.

In one embodiment of a bipolar battery, a connector is attached to an end of the flow channel distal to the electrochemical cell.

In one embodiment of the bipolar battery, the connector includes a sealing cap in threaded engagement with the flow channel.

In one embodiment of the bipolar battery, the seal has a rectangular configuration, wherein the injection and drain features are disposed on one side of the rectangular configuration.

In one embodiment of the bipolar battery, the injection and discharge structures are a plurality of, and disposed on a plurality of sides of the rectangular structure, respectively.

In one embodiment of a bipolar battery, the at least one seal is disposed between the first end plate and one of the plurality of electrochemical cells, between two adjacent electrochemical cells, or between one of the plurality of electrochemical cells and the second end plate.

In one embodiment of the bipolar battery, the bipolar battery is a lithium ion battery.

In one embodiment of the bipolar battery, a separator is disposed between adjacent two of the plurality of electrochemical cells.

The present application solves both the problems of electrolyte injection and formation gas venting using one structure by introducing an injection and venting structure at the seal for both the injection of electrolyte and the formation gas venting. In addition, the injection and discharge structure is provided in the circumferential direction of the sealing member, which is suitable for the stacked structure of the battery cells inside the battery. The injection and drain structure can also be connected to existing electrolyte flow paths inside the bipolar battery, so that no additional structural modifications need to be made inside the bipolar battery. The injection and discharge structure of the application has the advantages of simplicity and easy implementation, and has no requirement on the thickness of the battery unit, so that the light weight of the battery is realized.

Other aspects and features of the present application will become apparent from the following detailed description, which proceeds with reference to the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the application, for which reference should be made to the appended claims. It should be further understood that the drawings are merely intended to conceptually illustrate the structures and procedures described herein, and that, unless otherwise indicated, they are not necessarily drawn to scale.

Drawings

The present application will be more fully understood from the detailed description given below with reference to the accompanying drawings, in which like reference numerals refer to like elements throughout the views. Wherein:

fig. 1 is a diagram of an assembly of a first end plate or a second end plate in combination with an electrochemical cell to which the present application relates;

fig. 2 is a schematic view of a separator to be incorporated into an electrochemical cell;

fig. 3 is a partial schematic view of a seal to be incorporated into an electrochemical cell;

FIG. 4 is a schematic view of an embodiment of a seal according to the present application;

FIG. 5 is a schematic view of a plurality of electrochemical cells in combination;

FIG. 6 is a schematic view of an embodiment of a fitting according to the present application.

Detailed Description

To assist those skilled in the art in understanding the subject matter claimed herein, a detailed description of the present application is provided below along with accompanying figures.

FIGS. 1-6 show schematic views of various components of a bipolar battery to which the present application relates, while FIGS. 1-5 schematically reflect several intermediate states in the assembly process of the bipolar battery.

Fig. 1 is a diagram of an assembly of a first end plate or a second end plate in combination with an electrochemical cell according to the present application. Fig. 2 is a schematic view of a separator to be incorporated into an electrochemical cell. Fig. 3 is a partial schematic view of a seal to be incorporated into an electrochemical cell. FIG. 4 is a schematic view of an embodiment of a seal according to the present application. Fig. 5 is a schematic view of a plurality of electrochemical cells being assembled. FIG. 6 is a schematic view of an embodiment of a fitting according to the present application.

Referring to fig. 1 and 5 in combination, the present application is directed to a bipolar battery comprising a first end plate 1, a second end plate (not shown), an electrochemical cell configuration located between the first end plate 1 and the second end plate. Wherein the first end plate 1 and the second end plate are opposite and have opposite polarities, i.e. one end plate is a positive end plate and the other end plate is a negative end plate. The electrochemical cell construction employs a stacked structure comprising a plurality of electrochemical cells 2 arranged in an end-to-end configuration. An electrochemical cell configuration may include any number of electrochemical cells depending on the selected voltage of the battery and the individual voltage of each individual electrochemical cell. Each electrochemical cell 2 includes a spaced anode and cathode therein. Wherein the anode of one electrochemical cell faces the cathode of the next electrochemical cell. Between the adjacent two electrochemical cells is also provided a member called a bipolar (separator) plate, and the anode of the previous electrochemical cell is connected to the cathode of the next electrochemical cell through the bipolar plate, whereby the adjacent two electrochemical cells are connected in series.

A plurality of seals are provided around the electrochemical cells 2 in their circumferential direction to electrochemically isolate adjacent electrochemical cells. The seal is provided with injection and discharge structures 5 in its circumferential direction to allow electrolyte to flow into the individual electrochemical cells via the seal or to allow gases within the electrochemically produced electrochemical cells to exit via the seal. The fill and drain structure is sealed after the bipolar battery is completed.

The injection and discharge structure is arranged on the circumferential direction of the sealing element, so that two problems of injection of electrolyte and discharge of formation gas can be solved simultaneously. And this structure is particularly useful in electrochemical cell constructions in a stacked configuration, where fluid enters or exits from one side of the electrochemical cell construction, and thus there is no thickness requirement for the electrochemical cell.

In particular, with reference to fig. 3 to 4, the injection and discharge structure 5 comprises an opening 51 provided on the sealing element 4 and a flow channel 52 predisposed on the sealing element 4, the flow channel 52 being in fluid communication with the opening 51. The openings 51 are oriented in the circumferential direction. The flow channels 52 may extend from the exterior of the electrochemical cell construction through the openings 51 to the interior of the electrochemical cell construction, while the extension of the flow channels may be routed according to a specific design, thereby defining a supply route for the electrolyte. Regardless of the supply route, however, electrolyte enters the electrochemical cell structure from the circumferential direction, as does the venting of the forming gas, and exits the electrochemical cell structure from the circumferential direction, unlike conventional designs in which electrolyte injection structures or forming gas venting structures are provided on the end faces of the electrochemical cell structure. In addition, the injection and discharge structure of the present application uses few parts due to simple design, and does not occupy the space of the battery structure in the axial direction, so that the weight of the battery can be reduced.

Returning to fig. 5, fig. 5 shows that a plurality of stacked electrochemical cells 2 have a corresponding number of injection and drain structures 5, i.e. one per electrochemical cell structure and are independent from each other. Of course, it is contemplated that multiple injection and drain structures may have portions in common, such as, but not limited to, branching off individual flow passages in multiple injection and drain structures and connecting to a manifold. It is also contemplated that a restriction may be provided on each of the injection and discharge structures to control flow, for example and without limitation.

In addition, the end of the flow channel 52 leading to the electrochemical cell can be connected to the existing electrolyte flow path within the electrochemical cell, thus eliminating the need for additional modifications to the internal structure of existing bipolar batteries. At the same time, the end of the flow channel 52 remote from the electrochemical cell can be connected to the connector 6. Figure 6 shows a schematic view of one embodiment of a joint. The fitting 6 includes a sealing cap 61 that is in threaded engagement with the flow passage 52. When the injection operation or the discharge operation is performed, the sealing cap 61 is unscrewed. After the operation is completed, the seal cap 61 is screwed. This design facilitates both the injection and discharge operations. The tabs may be optionally retained or removed and the fill and drain structure sealed before the bipolar battery is completed.

In one embodiment of the present application, the first end plate 1, the second end plate, each electrochemical cell 2 and its seal 4 have a rectangular configuration. Each injection and discharge structure 5 is arranged on one side of the rectangular structure of the seal, as shown in fig. 5, these injection and discharge structures 5 being uniformly arranged on the same side of the rectangular structure. It is of course conceivable that the injection and discharge structures are arranged on different sides of the rectangular structure, depending on the specific design; or for any one side of each seal, there may be a plurality of injection and discharge structures, arranged on the same side; or for each seal, the injection and discharge structures may be arranged on two, three or even four sides of the seal. Of course, the structure of the first end plate, the second end plate, the electrochemical cells, and the seals may not be limited to a rectangular structure, and thus the number of injection and discharge structures is not limited to one-to-one correspondence with the electrochemical cells. Similarly, these injection and drainage structures are arranged in the circumferential direction of the seal.

The seal may be disposed between the first end plate and one of the plurality of electrochemical cells, between two adjacent electrochemical cells, or between one of the plurality of electrochemical cells and the second end plate. The seal member may also be a seal member that seals each electrochemical cell to electrochemically isolate the electrochemical cell from other electrochemical cells. Based on the different electrochemical cell configuration designs in a bipolar battery, the seal is used to seal at least a portion of the bipolar battery and the flow channels through the seal can communicate with the conduits inside the battery under the concepts of the present application.

Taking a bipolar lithium battery as an example, the present application is manufactured by the sequence shown in fig. 1 to 5. First, as shown in fig. 1, one electrochemical cell 2 is coupled to a first end plate 1 or a second end plate; second, as shown in fig. 2, a separator 3 is bonded to an end surface of the electrochemical cell 2 that is not bonded to the first end plate or the second end plate, and the separator 3 may be a rubberized separator; thirdly, as shown in fig. 3, a seal 4, such as a rectangular bead of sealant shown in the figure, is bonded to the electrochemical cell 2 and the separator 3, fig. 4 shows the seal 4 pre-configured with flow channels 52, the flow channels 52 being bonded to the electrochemical cell 2 and the separator 3 together with the seal 4; fourth, as shown in fig. 5, a second, third, fourth, etc. plurality of electrochemical cells are stacked on top of the first one of the above electrochemical cells in a similar procedure as described above. The flow channels extending from these seals may be connected to connectors, the sealing cap of which may be unscrewed during electrolyte injection or gas suction from the cell structure cavity, and tightened after use.

While specific embodiments of the present application have been shown and described in detail to illustrate the principles of the application, it will be understood that the application may be embodied otherwise without departing from such principles.

Claims

1. A bipolar battery, comprising:

a first end plate;

a second end plate opposite the first end plate;

a plurality of electrochemical cells (2) stacked between the first end plate and the second end plate, adjacent two of the plurality of electrochemical cells (2) being connected in series; and

a plurality of seals (4) arranged circumferentially around the plurality of electrochemical cells (2), at least one seal of the plurality of seals being arranged with an injection and drain structure (5) in the circumferential direction, the injection and drain structure (5) being configured to allow electrolyte to flow into the electrochemical cells via the seal or to allow gas in the electrochemical cells to exit via the seal.

2. The bipolar battery according to claim 1, wherein: the injection and discharge structure (5) comprises an opening (51) provided on the seal (4) and a flow channel (52) predisposed on the seal, the flow channel (52) being in fluid communication with the opening (51).

3. The bipolar battery according to claim 2, wherein: one end of the flow channel (52) leading to the electrochemical cell (2) is connected to an existing electrolyte flow path within the bipolar battery.

4. The bipolar battery according to claim 2, wherein: the end of the flow channel (52) remote from the electrochemical cell (2) is connected to a connector (6).

5. The bipolar battery according to claim 4, wherein: the joint (6) comprises a sealing cover (61) which is in screwed fit with the flow channel (52).

6. The bipolar battery according to claim 1, wherein: the seal (4) has a rectangular configuration, wherein the injection and discharge structure (5) is arranged on one side of the rectangular configuration.

7. The bipolar battery according to claim 6, wherein: the injection and discharge structures (5) are provided in plurality, respectively on a plurality of sides of the rectangular structure.

8. The bipolar battery according to any one of claims 1-7, wherein: the at least one seal is disposed between the first end plate and one of the plurality of electrochemical cells, between two adjacent electrochemical cells, or between one of the plurality of electrochemical cells and the second end plate.

9. The bipolar battery according to any one of claims 1 to 7, wherein: the bipolar battery is a lithium ion battery.

10. The bipolar battery according to any one of claims 1 to 7, wherein: a separator (3) is disposed between adjacent two of the plurality of electrochemical cells (2).