CN211929603U - Multi-pole terminal lithium battery - Google Patents

Abstract

A multi-pole terminal lithium battery is disclosed. The utility model discloses an in the embodiment, multipolar post terminal lithium cell can include: shell, apron and naked electric core. The cover plate is provided with at least N pairs of pole terminals, at least N liquid injection holes and at least one explosion-proof valve, and each pair of pole terminals comprises a positive pole terminal and a negative pole terminal; the bare cell comprises at least N cathode plates, at least 2N diaphragms and at least N anode plates; every in naked electric core the positive pole piece is through its utmost point ear and one the welding of positive post terminal, every the negative pole piece is through its utmost point ear and one the welding of negative post terminal, the outside cladding of naked electric core is insulated bag and is placed in the shell, the top cover the apron, the shell with the apron welding is in order sealed naked electric core, electrolyte in the naked electric core via the notes liquid hole of apron is injected into in the naked electric core, N is more than or equal to 2's integer. The embodiment of the utility model provides a not only can effectively reduce the battery internal resistance, the inside temperature distribution of battery is also more even moreover, still can reduce the risk of outage suddenly simultaneously.

Description

Multi-pole terminal lithium battery

technical field

The utility model relates to the technical field of lithium batteries, in particular to a multi-pole terminal lithium battery.

Background technique

With the development of the new energy vehicle market, consumers demand that battery modules (packs) have higher energy density and lower costs. Therefore, it is an effective method to reduce the structural components that do not provide energy storage in battery modules. , which requires the cells that make up the battery module to have a larger size and strength.

At present, in the field of large-scale lithium-ion batteries, it is mainly on the basis of primary batteries that the length, width and height of the battery are simply increased to accommodate more electrode sheets and electrolytes, so as to achieve the purpose of improving battery capacity and energy density. But it also brings a series of problems such as difficult injection and uneven current distribution.

In the related art, while increasing the cell size to improve the energy density of the battery module, it introduces complex thermal management, uneven current density during high-current charging and discharging, decreased cell structural strength, difficult liquid injection, and complex cell technology. , security risks increase, battery module maintenance is difficult and other issues.

SUMMARY OF THE INVENTION

In order to solve the above technical problems or other technical problems in whole or in part, an embodiment of the present invention provides a multi-pole post terminal lithium battery.

According to one aspect of the present utility model, a multi-pole terminal lithium battery is provided, comprising:

shell;

The cover plate is provided with at least N pairs of pole pole terminals, at least N liquid injection holes and at least one explosion-proof valve, and each pair of pole pole terminals includes a positive pole pole terminal and a negative pole pole terminal;

The bare cell includes at least N cathode sheets, at least 2N separators, and at least N anode sheets, the at least N pairs of cathode sheets, at least N separators, and at least N pairs of anode sheets are arranged according to the cathode sheets outside, the separator in the middle, and the anode sheet Sequential winding or lamination including sheets;

Wherein, each of the anode pieces in the bare cell is welded with one of the positive pole terminals through its tabs, and each of the cathode pieces is welded with one of the negative pole terminals through its tabs, and the bare cell is welded with one of the negative pole terminals. The outer core of the core is covered with an insulating bag and placed in the casing, the top end covers the cover plate, the casing and the cover plate are welded to seal the bare cell, and the electrolyte is injected through the liquid injection hole of the cover plate. Injected into the bare cell, N is an integer greater than or equal to 2.

In at least some embodiments, the N pairs of pole terminals are evenly distributed on the cover plate.

In at least some embodiments, the N pairs of pole terminals are evenly distributed on the cover plate, including: at least all positive pole terminals in the N pairs of pole terminals are arranged on one side of the cover plate and evenly distributed, the N pairs of pole terminal All the negative pole terminals in the counter pole terminal are arranged on the other side of the cover plate and are evenly distributed.

In at least some embodiments, the position of the tab on each of the anode sheets corresponds to the position of the corresponding one of the positive pole terminal on the cover plate; the position of the tab on each of the cathode sheets corresponds to the position of the corresponding one of the tabs on the cathode sheet. The positions of the negative pole terminal on the cover plate correspond to each other.

In at least some embodiments, the bare cell further includes N stop frames, each of which is clamped between the tabs of the two anode sheets or the two cathode sheets.

In at least some embodiments, each of the liquid injection holes is disposed between adjacent pole terminals.

In at least some embodiments, the at least N liquid injection holes are symmetrically distributed on the cover plate.

In at least some embodiments, the explosion-proof valve is arranged in a middle position of the cover plate.

The multi-pole terminal lithium battery provided by the embodiment of the present invention adopts the design of the multi-pole terminal, which can not only effectively reduce the internal resistance of the battery, but also distribute the current density of the pole piece more uniformly during the charging and discharging of the battery cell, and the multi-pole terminal is divided into two parts. If the current is increased, the pole will generate less heat, and the temperature distribution inside the battery will be more uniform. At the same time, if a pole is welded off, it can still operate effectively, and the risk of sudden power failure can also be reduced.

Description of drawings

FIG. 1 shows the external three-dimensional structure of a multi-pole terminal lithium battery in an embodiment of the present invention.

FIG. 2 shows a schematic diagram of a disassembled structure of a multi-pole lithium battery in an embodiment of the present invention.

3 is a top cross-sectional schematic diagram of a cover plate in a multi-pole lithium battery according to an embodiment of the present invention.

4 is a schematic structural diagram of a bare cell in a multi-pole lithium battery according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of a manufacturing process of a multi-pole lithium battery in an embodiment of the present invention.

Description of reference numbers:

10. Multi-pole lithium battery; 11. Shell; 12. Cover plate; 13. Bare cell; 121. Positive pole terminal; 122. One negative pole terminal; 123. Liquid injection hole; 124. Explosion-proof valve; 131. Cathode sheet; 132, anode sheet; 133, pole ear; 134, stop frame.

Detailed ways

The embodiments of the present utility model will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the various embodiments of the present invention and the various features therein can be arbitrarily combined with each other.

As mentioned above, in the field of lithium-ion batteries, in order to improve the energy density of the battery module while reducing the cost, it is an effective method to simplify the package structure of the battery module under the condition of the same battery material. At this time, to improve the energy density and strength of a single cell, it is necessary to use a large-sized cell, and at the same time, the cell also needs to have extremely high strength. Large-sized cells mean large-sized pole pieces. At this time, if the unipolar column terminal design of traditional power batteries is also used, on the one hand, the current density distribution of the pole pieces will be more uneven during high current charging and discharging, and on the other hand The heat of the pole terminal is more serious, and the heat dissipation inside the battery is more difficult, and the temperature is more uneven. On thermal runaway, battery modules require more explosion-proof valves. The larger size of the larger cell means more electrolyte is needed. The traditional design has low injection efficiency and requires a longer standing time, reducing production efficiency.

In view of the above technical problems, the basic idea of the embodiment of the present invention is to provide a multi-pole terminal lithium battery, which adopts the design of multi-pole terminal, the design of at least one explosion-proof valve and the design of double liquid injection on the battery core. Not only can the internal resistance of the battery be effectively reduced, but also the current density distribution of the pole pieces is more uniform when the battery is charged and discharged, and the multi-pole terminals share the current, so the poles generate less heat and the internal temperature distribution of the battery is more uniform. At the same time, if a pole is welded off, it can still operate effectively, and it can also reduce the risk of sudden power failure. In addition, the design of double explosion-proof valves can effectively reduce the risk of thermal runaway. In addition, the double injection hole design improves the injection efficiency and reduces the standing time. In addition, in the embodiment of the present invention, through the design of the uniform distribution of the plurality of pole terminals, the connection piece with higher strength is adopted, and the strength between the batteries is also enhanced. Therefore, the structural part of the battery module can be simple The structural strength design can meet the use requirements.

1 and 2 show an exemplary structure of a multi-pole terminal lithium battery in an embodiment of the present invention. FIG. 1 shows an external three-dimensional structure of a multi-pole terminal lithium battery in an embodiment of the present invention. A schematic structural diagram of the disassembly of the cover plate and the bare cell in the multi-pole lithium battery in the embodiment of the present invention is shown.

As shown in FIG. 1 , the multi-pole terminal lithium battery according to the embodiment of the present invention may include: a casing 11 , a cover plate 12 and a bare cell 13 .

Figure 3 shows a schematic cross-sectional view of the top of the cover plate. As shown in FIG. 2 , the cover plate 12 is provided with at least N pairs of pole terminals, at least N liquid injection holes 123 and at least one explosion-proof valve 124 , and each pair of pole terminals includes a positive pole terminal 121 and a negative pole terminal 122 . The example in FIG. 2 only shows the case of N=2, but in practical applications, N may take an integer greater than 2. That is to say, there can be more than two pairs of pole terminals, and correspondingly, more than two liquid injection holes 123 can be provided. The number of pairs of pole terminals and the number of liquid injection holes can be designed according to specific application requirements. , the embodiments of the present invention are not limited. In addition, the number of pole terminal pairs and the number of injection holes are not necessarily equal.

In some examples, in order to make the current density distribution of the pole pieces more uniform when the cells are charged and discharged, the N pairs of pole terminals are evenly distributed on the cover plate 12 . Specifically, in the example of N=2 shown in FIGS. 1 and 2 , two positive pole terminals 121 and two negative pole pole terminals 122 are provided on the cover plate 12 , which are marked as positive pole terminals in FIGS. 1 and 2 respectively. 121-A, positive pole terminal 121-B, negative pole terminal 122-A, negative pole terminal 122-B, positive pole terminal 121-A, positive pole terminal 121-B are arranged on the left side of the top of cover plate 12, and its The spacing is equal to the distance from the positive pole terminal 121-B to the center of the top of the cover plate (that is, the position of the explosion-proof valve 124). The distance from the column terminal 122-B to the center of the top of the cover plate (that is, the position of the explosion-proof valve 124), that is, the two positive column terminals 121 and the two negative column terminals 122 are respectively arranged on both sides of the top of the cover plate 12 and symmetrically distributed . Through the design of uniform distribution, the current density distribution of the pole pieces is more uniform when the battery is charged and discharged, the multi-pole terminal can evenly distribute the current, the poles generate less heat, and the internal temperature distribution of the battery is more uniform. At the same time, if a pole is welded off, it can still operate effectively, and the risk of sudden power failure can also be reduced. In addition, through the design of the uniform distribution of multiple pole terminals, higher-strength connecting pieces can be used, and the strength between batteries is also enhanced. Therefore, the structural part of the battery module can be designed with simple structural strength to meet the needs of use. Require.

In some examples, the multi-pole terminal lithium battery adopts the design of multiple liquid injection holes, which can improve the liquid injection efficiency and reduce the standing time. In this example, when the design of multiple liquid injection holes is adopted, each liquid injection hole can be arranged between adjacent pole terminals. Specifically, in the example of N=2 shown in FIG. 1 and FIG. 2 , two liquid injection holes 123 are provided on the cover plate 12 , which are respectively marked as liquid injection holes 123-1 and 123-2. The liquid hole 123-1 is provided between the positive electrode column terminal 121-A and the positive electrode column terminal 121-B, for example, it may be provided at an intermediate position between the two. The liquid injection hole 123-2 is provided between the negative electrode column terminal 122-A and the negative electrode column terminal 122-B, and may also be provided at an intermediate position between the two. In this example, in order to better ensure that the current density distribution of the pole piece is more uniform when the battery is charged and discharged, the liquid injection hole 123-1 and the liquid injection hole 123-2 are also symmetrical with respect to the middle line of the top of the cover plate 12. Design, evenly distributed.

In some examples, the multi-pole-terminal lithium battery can adopt the design of multiple explosion-proof valves 124 , for example, the design of multiple explosion-proof valves can effectively reduce the risk of thermal runaway. In this example, the explosion-proof valve 124 may be positioned in the middle of the top surface of the cover plate 12 . Specifically, in the example of N=2 shown in FIG. 1 and FIG. 2 , an explosion-proof valve 124 is provided on the cover plate 12 , and the explosion-proof valve 124 is arranged in the middle position of the top plane of the cover plate 12 . In this way, the pole terminal, the liquid injection hole and the explosion-proof valve on the top surface of the cover plate 12 can be uniformly designed, on the one hand, it is convenient for assembly and processing, on the other hand, it can better ensure that the current density distribution of the pole piece is more uniform when the battery is charged and discharged. .

FIG. 3 shows a disassembled view of the internal structure of the bare cell 13 and its relationship with various components on the cover plate 12 . In the embodiment of the present invention, the bare cell 13 may include at least N pieces of cathode sheets 131 , at least 2N pieces of diaphragms (not shown in the figure), and at least N pieces of anode sheets 132 . As shown in FIG. 3, at least N pairs of cathode sheets 132, at least N separators and at least N pairs of anode sheets 132 may be rolled in the order of cathode sheet 131 outside, separator (not shown) in the middle, and anode sheet 132 inside The bare cells 13 are formed by winding or lamination. The example in FIG. 3 only shows the case of N=2, but in practical applications, N may take an integer greater than 2. That is to say, corresponding to the design of the multi-pole terminal on the cover plate 12 , the number of cathode sheets 131 and anode sheets 132 can also exceed 2. In practical applications, the number of cathode sheets 131 and anode sheets 132 is generally the number of pole terminals. The multiple of , can be designed according to specific application requirements, which is not limited by the embodiment of the present invention.

In the embodiment of the present invention, each anode piece 132 in the bare cell 13 is welded with a positive pole terminal 121 through its tab 133, and each cathode piece 131 is welded with a negative pole terminal 122 through its pole tab 133, and the bare battery The outside of the core 12 can be covered with an insulating bag (not shown in the figure) and placed in the casing 11, the top end is covered with a cover plate 12, the casing 11 and the cover plate 12 are welded to seal the bare cell 13, the electrolyte (not shown in the figure) shown) is injected into the bare cell 13 through the liquid injection hole 123 of the cover plate 12 . In some examples, the tabs 133 on each anode sheet 132 corresponding to the same positive pole terminal 121 in the bare cell 13 may be aligned and welded together, and then welded to the positive pole terminal 121 . Similarly, the tabs 133 on each cathode sheet 131 corresponding to the same negative pole terminal 122 in the bare cell 13 may be aligned and welded together, and then welded to the negative pole terminal 122 .

In the embodiment of the present invention, the position of the upper tab of each anode sheet 132 corresponds to the position of a corresponding positive pole terminal 121 on the cover plate 12, and the position of the upper tab of each cathode sheet 131 corresponds to a corresponding negative electrode The positions of the post terminals 122 on the cover plate 12 correspond to each other. Taking the above N=2 as an example, corresponding to the design of the two pairs of pole terminals in FIG. 2 , the bare cell 13 may include two cathode sheets 131 and two anode sheets 132 , which are marked as cathode sheets 131 -A and cathode sheets 131 respectively. -B, anode sheet 132-A, anode sheet 132-B, the position of the tab 133-A1 on the cathode sheet 131-A corresponds to the position of the negative pole terminal 122-A on the cover plate 12, the cathode sheet 131-B The position of the tab 133-B1 on the cover plate 12 corresponds to the position of the negative pole terminal 122-B on the cover plate 12, and the position of the pole tab 133-A2 on the anode plate 132-A corresponds to the position of the positive pole terminal 121-A on the cover plate 12. The positions of the tabs 133-B2 on the anode sheet 132-A correspond to the positions of the positive pole terminals 121-B on the cover plate 12. In this way, during assembly, the cathode piece 131-A is connected to the negative pole terminal 122-A through its tab 131-A1, the cathode piece 131-B is connected to the negative pole terminal 122-B through its pole tab 131-B1, and the anode piece 132 -A is connected to the positive pole terminal 121-A through its tab 131-A2, and the anode sheet 132-B is connected to the positive pole terminal 121-B through its tab 131-B2.

As shown in FIG. 1 , the bare cell 12 may further include N stop frames 134 , and each stop frame 134 is clamped between the tabs 133 of the two anode sheets 131 or the two cathode sheets 132 . The retaining frame 133 can not only fix the cathode sheet and the anode sheet in the bare cell 12 , but also further play the role of sealing the bare cell 12 to prevent leakage of the electrolyte.

FIG. 5 shows an exemplary manufacturing flow chart of the above-mentioned multi-pole lithium battery according to the embodiment of the present invention. As shown in FIG. 5 , the process of making the above-mentioned multi-pole lithium battery may include the following steps:

Step S510, winding or stacking at least N pairs of cathode sheets, at least 2N pieces of separators, and at least N pairs of anode sheets in the order that the cathode sheet is outside, the diaphragm is in the middle, and the anode sheet is inside to complete the assembly of the bare cell, and the composition is composed of: In the formed bare cell, the position of the tab on each anode sheet is aligned with a corresponding positive pole terminal, and the position of the tab on each cathode sheet is aligned with a corresponding negative pole terminal;

In some examples, in step S510, before the step of winding or stacking sheets, it may further include: fabricating at least N pairs of cathode sheets and at least N pairs of anode sheets, and at the same time, according to the arrangement of the negative pole terminal corresponding to each cathode sheet on the cover plate. The pole tabs are arranged at corresponding positions on the cathode sheet, and the tabs are arranged at corresponding positions on the anode sheet according to the position of the positive pole terminal corresponding to each anode sheet on the cover plate.

For example, in step S510, the following steps may be included: making a cathode sheet and an anode sheet, along the width direction of the cathode sheet or the anode sheet, the coating area is located on both sides, the blank area is located in the middle, and the cathode sheet and the anode sheet are rolled or The number of laminated sheets is divided into A-type sheets (that is, the cathode sheet 131-A, anode sheet 132-A above, where the tabs are located at the edge), B-type sheets (that is, the cathode sheet 131-B above, Anode sheet 132-B, the tabs are located relatively inward (for example, a quarter)) two types; according to the position of the pole terminal after lamination, design A-type and B-type, as shown in Figure 2 and Figure 2 As shown in 4, the tabs are located on the same side of the pole piece, which is then die-cut and then assembled. The chip method is assembled into a bare cell.

Step S520, welding the cathode sheet and the anode sheet in the bare cell to the corresponding pole terminal on the cover plate;

Specifically, each anode piece in the bare cell is welded to a corresponding positive pole terminal on the cover plate through its tab, and each cathode piece in the bare cell is connected to a corresponding negative pole terminal on the cover through its tab welding;

In this step, the tabs of the bare cell can be aligned and welded together first, and then the tabs can be welded to the poles of the special cover plate respectively.

Step S530, sealing the bare cell with the casing and the cover plate;

Specifically, the bare cell is covered with an insulating bag and then placed in the casing, the top of the bare cell is covered with a cover plate, and the cover plate and the casing are sealed and welded.

In some examples, in step S530 , the method may further include: respectively installing a stopper between the tabs of the two anode sheets and between the tabs of the two cathode sheets in the bare cell. That is, the insulating bag and the stop frame are installed, the bare cell is put into the case, and the cover plate and the case are sealed and welded.

In step S540, liquid injection and packaging are performed to obtain a multi-pole lithium battery.

Specifically, the electrolyte is injected into the bare cell through at least one of the at least N liquid injection holes on the cover plate, and the multi-pole terminal lithium battery is obtained after aging, formation, sealing, volume separation, and detection. In practical applications, the cells with qualified moisture can be injected into the required electrolyte through a special liquid injection machine, and the required electrolyte can be injected into the two vacuum holes at the same time; The core, the packaging package is completed.

Similarly, in the above production method, N is an integer greater than or equal to 2.

In some examples, before step S510, it may further include: step S500, making a cover plate, the cover plate has at least N pairs of pole terminals, at least N liquid injection holes and at least one explosion-proof valve, and each pair of pole terminals includes one Positive pole terminal and one negative pole terminal.

Specifically, step S500 may include the following steps: step a1, installing N pairs of pole terminals on the cover plate, and making N pairs of pole terminal terminals evenly distributed on the cover plate; step a2, punching at least N liquid injection holes, and each liquid injection hole is arranged between adjacent pole terminals of the same polarity; in step a3, at least one explosion-proof valve is installed on the cover plate. It should be noted that the execution order of step a1 to step a3 is not limited, and may be executed simultaneously, or any other suitable sequence may be adopted.

The multi-pole terminal lithium battery of the embodiment of the present invention adopts the design of multi-pole terminal, which can effectively reduce the internal resistance of the battery, and the current density distribution of the pole piece is more uniform during charging and discharging. The column generates less heat and the temperature distribution inside the battery is more uniform. At the same time, if a pole is welded and falls off, it can still operate effectively, reducing the risk of sudden power failure. The double explosion-proof valve design effectively reduces the risk of thermal runaway. The double injection hole design improves the injection efficiency and reduces the standing time. A plurality of pole terminals are evenly distributed, and higher-strength connecting pieces are used to enhance the strength between batteries. Therefore, the package structure part can be designed with a simple structure and strength to meet the requirements of use.

The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field of the present invention can easily think of changes within the technical scope disclosed by the present invention. Or replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (8)

1. A multi-pole terminal lithium battery comprising:

a housing;

the cover plate is provided with at least N pairs of pole terminals, at least N liquid injection holes and at least one explosion-proof valve, and each pair of pole terminals comprises a positive pole terminal and a negative pole terminal;

the bare cell comprises at least N cathode sheets, at least 2N diaphragms and at least N anode sheets, wherein the at least N pairs of cathode sheets, the at least N diaphragms and the at least N pairs of anode sheets are wound or laminated in the sequence that the cathode sheets are arranged outside, the diaphragms are arranged in the middle and the anode sheets are arranged inside;

wherein, every in the naked electric core the positive pole piece is through its utmost point ear with one positive post terminal welding, every the negative pole piece is through its utmost point ear and one negative post terminal welding, the outside cladding of naked electric core is insulated bag and is placed in the shell, the top covers the apron, the shell with the apron welding is in order to seal naked electric core, electrolyte via annotate the liquid hole on the apron and is injected into in the naked electric core, N is more than or equal to 2 integer.

2. The multi-pole post terminal lithium battery of claim 1, wherein the N pairs of post terminals are evenly distributed on the cap plate.

3. The multi-pole terminal lithium battery of claim 1, wherein the N pairs of pole terminals are uniformly distributed on the cap plate, comprising: all positive post terminals in the at least N pairs of post terminals set up one side and the evenly distributed of apron, all negative post terminals in the N pairs of post terminals set up the another side and the evenly distributed of apron.

4. The multi-pole terminal lithium battery as claimed in claim 1 or 2, wherein a tab on each of the anode sheets corresponds to a position of a corresponding one of the anode pole terminals on the cap plate; and the position of the tab on each cathode plate corresponds to the position of the corresponding negative pole terminal on the cover plate.

5. The multi-pole terminal lithium battery of claim 1, wherein the bare cell further comprises N stopper frames, each of the stopper frames being caught between tabs of two of the anode sheets or two of the cathode sheets.

6. The multi-pole terminal lithium battery of claim 1, wherein each of the injection holes is provided between adjacent pole terminals.

7. The multi-pole terminal lithium battery of claim 1, wherein the at least N electrolyte injection holes are symmetrically distributed on the cap plate.

8. The multi-pole terminal lithium battery of claim 1, wherein the explosion-proof valve is provided at an intermediate position of the cap plate.

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