CN219040639U

CN219040639U - Telescopic lithium battery pack structure

Info

Publication number: CN219040639U
Application number: CN202223118454.8U
Authority: CN
Inventors: 杜新雨; 李先锋; 曲超
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2022-11-23
Filing date: 2022-11-23
Publication date: 2023-05-16
Anticipated expiration: 2032-11-23

Abstract

The utility model discloses a telescopic lithium battery pack structure, and belongs to the field of lithium batteries. The utility model comprises two clamping pieces which are arranged in parallel, wherein the clamping pieces are of a plane structure, a single cell is arranged between the two clamping pieces, the two clamping pieces are connected through a screw rod, two ends of the screw rod respectively penetrate through the two clamping pieces, two ends of the screw rod are respectively provided with a spring assembly, each spring assembly comprises a bolt, a gasket and a die spring which are sequentially arranged, and the die spring is sleeved on the screw rod between the gasket and the clamping piece. According to the utility model, the die spring and the clamping piece are arranged, so that dynamic control of the binding force of the battery pack in the initial stage of assembly is realized, and the expansion force gradually increased in the use process of the battery pack can be relieved.

Description

Telescopic lithium battery pack structure

Technical Field

The utility model belongs to the field of lithium batteries, and particularly relates to a telescopic lithium ion battery pack structure.

Background

Lithium ion batteries have contributed to the advancement of the electronics industry and have become an important power accessory for portable electronic devices. As technology further matures, lithium ion batteries also began to enter the electric automobile market and are widely used for grid energy storage. Energy, power, capacity, discharge rate, cost, cycle life, safety, and environmental impact are parameters that need to be considered when employing lithium ion batteries in various applications. While energy density is the most important factor of the device, cost, cycle life and safety are also key parameters together. On the other hand, for grid energy storage, cost, cycle life and safety become more important than energy density.

The safety performance and the cycle performance of the lithium ion battery are related to various factors, such as a battery system, design parameters, electrolyte and the like, an electric vehicle or energy storage application needs to connect a plurality of single batteries in series and parallel to form a module or a battery pack, the safety and the cycle life of the battery system after the battery is grouped are influenced by the battery operation environment, the other main influencing factors are the stress of the battery in the use process after the battery is grouped, the negative electrode materials used by the lithium ion battery mainly comprise graphite and silicon carbon materials, the graphite and the silicon carbon materials are characterized in that the expansion of the thickness of a negative electrode plate of the battery is carried out along with the cycle, the expansion of the battery is particularly obvious for the expansion of the battery of the silicon carbon negative electrode system, the overall thickness of the battery is increased after the expansion of the negative electrode, namely the expansion force of the grouped battery pack is increased, the expansion force is increased along with the cycle, and the expansion force is larger and larger, and the cycle performance and the safety performance of the battery are finally influenced.

In view of the above problems, it is common practice in the industry to add a Gap frame, foam or silica gel pad between groups of cells, but the problem of the Gap frame is that when the expansion thickness of the cells is smaller than the Gap distance, there is no binding force between the cells, which leads to an increase in the expansion speed of the cells, and the problem of the foam or silica gel pad is that the expansion thickness between the cells is limited, and in addition, if the binding force of the battery pack is large, the expandable space left for the cells in the battery pack is small, and if the binding force is small, the same problem as that of the Gap frame exists.

Disclosure of Invention

In view of the above problems, the present utility model provides a telescopic lithium battery pack structure, which can adjust the binding force in the battery pack group process, and can release the expansion force of a part gradually increasing along with the cycle, thereby improving the safety and the cycle life of the battery system.

The utility model provides a telescopic lithium battery pack structure, which comprises two clamping pieces which are arranged in parallel, wherein each clamping piece is of a plane structure, a single cell is arranged between the two clamping pieces, the two clamping pieces are connected through a screw rod, two ends of the screw rod respectively penetrate through the two clamping pieces, two ends of the screw rod are respectively provided with a spring assembly, each spring assembly comprises a bolt, a gasket and a die spring which are sequentially arranged, and the die spring is sleeved on the screw rod between the gasket and the clamping piece.

Further, the clamping member is a rectangular end plate.

Further, the screw rods between the end plates are disconnected to form disconnected ends, one screw rod forms two disconnected ends, a return frame is arranged between the two disconnected ends, the two disconnected ends penetrate through the return frame and are arranged in the return frame, the two disconnected ends are respectively connected with a spring assembly, and a die spring in each spring assembly is in contact with the return frame.

Further, the number of the screws is 4-6.

Further, the clamping piece is a cross beam, and the single cells are clamped between the cross beams.

Further, an end plate is provided, which is clamped between the cross member and the single cell.

In the prior art, the end plate is fixed mainly in a welding mode, the size is fixed after welding, no rebound space exists, the rebound space is reserved for the battery pack in a mode of combining the bolt and the die spring, and the binding force of the battery pack in the using process can be ensured, wherein the assembling mode of the end plate and the die spring can be realized in the following three modes.

The first way is: the hole is formed in the edge of the end plate, a screw rod is used for penetrating through the hole for fixing and fastening the battery pack, a die spring is located between the end plate and the bolt, a gasket is additionally arranged between the bolt and the die spring, the die spring penetrates through the screw rod, the initial pretightening force of the battery pack and the telescopic distance and the telescopic force of the battery pack in the use process can be adjusted by the bolt and the die spring, and schematic diagrams of the die spring and the end plate after assembly are shown in fig. 1 and 2.

The second way is: the movable cross beams are additionally arranged on two sides of the end plate, screw holes are formed in two sides of the cross beams and used for fixing and fastening the battery pack, the die springs are arranged between the cross beams and the bolts, gaskets are additionally arranged between the bolts and the die springs, the die springs penetrate through the screws, initial pretightening force of the battery pack, the telescopic distance and the telescopic force of the battery pack in the use process can be adjusted by the bolts and the die springs, and schematic diagrams of the die springs, the end plate and the cross beams after assembly are shown in fig. 3 and 4.

Third mode: the battery pack is characterized in that holes are formed in the edge positions of the end plates for the screws to penetrate, the end plates and the screws are fixed through bolts, the screws are fixed with the square frames through bolts, die springs are additionally arranged between the bolts and the square frames, the die springs penetrate through the screws, gaskets are additionally arranged between the bolts and the die springs, the square frames are provided with holes on two sides and are respectively connected with the end plates on the left side and the right side, the die springs and the bolts are arranged in the square frames, and the initial pretightening force of the battery pack and the telescopic distance and the telescopic force of the battery pack in the use process can be adjusted through the bolts and the die springs, so that the schematic diagrams of the die springs, the end plates and the square frames after the battery pack is assembled are shown in fig. 5 and 6.

The beneficial effects are that:

according to the utility model, the dynamic control of the binding force of the battery pack in the initial stage of assembly is realized by arranging the die spring and the clamping piece, more importantly, the problem that the expansion force gradually increased in the use process of the battery pack cannot be released can be relieved, the thickness of the positive pole piece and the negative pole piece of the battery can rebound along with the circulation of the battery, the negative pole piece is more obvious, the phenomenon is more prominent in the silicon-carbon negative pole, the integral thickness of the battery is increased, the internal expansion force of the battery pack cannot be released because the battery pack is assembled in a mode of welding end plates, and the expansion force gradually increases along with the increase of the use times of the battery.

Drawings

Fig. 1 is a front view of embodiment 1 of the present utility model.

Fig. 2 is a left side view of fig. 1.

Fig. 3 is a front view of embodiment 2 of the present utility model.

Fig. 4 is a left side view of fig. 2.

Fig. 5 is a front view of embodiment 3 of the present utility model.

Fig. 6 is a left side view of fig. 2.

In the figure, 1, a bolt; 2. a die spring; 3. a screw; 4. an end plate; 5. a gasket; 6. a cross beam; 7. and (5) a mold frame.

Detailed Description

The technical solutions of the embodiments of the present utility model will be clearly and completely described below in conjunction with the embodiments of the present utility model, and it is apparent that the described embodiments are only some embodiments of the present utility model, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Referring to fig. 1-2, the utility model provides a telescopic lithium battery pack structure, which comprises two clamping pieces which are arranged in parallel, wherein the clamping pieces are of a plane structure, the two clamping pieces are arranged, a single cell is arranged between the two clamping pieces, the two clamping pieces are connected through a screw rod 3, two ends of the screw rod 3 respectively penetrate through the two clamping pieces, two ends of the screw rod 3 are respectively provided with a spring assembly, the spring assembly comprises a bolt 1, a gasket 5 and a die spring 2 which are sequentially arranged, and the die spring 2 is sleeved on the screw rod 3 between the gasket 5 and the clamping pieces.

Referring to fig. 2, in one embodiment, the clamping member is a rectangular end plate 4.

Referring to fig. 5 to 6, in a specific embodiment, the screws 3 between the end plates 4 are broken to form broken ends, one screw 3 forms two broken ends, a mold returning frame 7 is disposed between the two broken ends, the two broken ends pass through the mold returning frame 7 and are placed in the mold returning frame 7, and a spring assembly is connected to the two broken ends, and the mold spring 2 in each spring assembly is in contact with the mold returning frame 7.

Referring to fig. 6, in one embodiment, the number of screws 3 is 6.

Referring to fig. 3-4, in one particular embodiment, the clamping members are cross beams 6, with the cells clamped between the cross beams 6.

Referring to fig. 3 to 4, in one embodiment, an end plate 4 is further provided, and the end plate 4 is sandwiched between the cross member 6 and the single cells.

The following are specific examples.

Example 1

This embodiment adopts the first mode to assemble the group battery, and the group battery is 7 strings of group batteries, and group battery mechanical component includes single cell, end plate 4, screw rod 3, mould spring 2, bolt 1, gasket 5, the single cell uses 50Ah square shell battery, and the battery size is 100mm (length) ×15mm (width) ×100mm (height: the shell is high, does not contain the utmost point post), battery negative pole is the silicon carbon material, end plate 4 is aluminium system end plate, and two altogether have, and the size is 120mm (length direction), 5mm (thickness) 105mm (height direction), end plate 4 edge trompil, for screw rod 3 to pass, the trompil diameter is 5mm, and every end plate 4 trompil quantity is 6, mould spring 2 external diameter 20mm, internal diameter 10mm, screw rod 3 diameter is 4mm, and bolt 1 uses with screw rod 3 is supporting, has gasket 5 between bolt 1 and the mould spring 2 after stacking, and two end plates 4 pass through screw rod 3 to be fixed at battery both ends, and mould spring 2 is between end plate 4 and bolt 1, separates with gasket 5 between mould spring 2 and the bolt 1, and the main view after the equipment is shown as fig. 1, and the left side view is as shown in fig. 2, and the battery is not drawn to the diagram in the figure, only characterizes battery assembly structure.

Example 2

In this embodiment, a battery pack is assembled in a second mode, the battery pack is a 7-string battery pack, the battery pack mechanical assembly comprises a single cell, an end plate 4, a screw 3, a die spring 2, bolts 1, gaskets 5 and cross beams 6, the single cell uses a 50Ah square shell cell, the cell size is 100mm (length) ×15mm (width) ×100mm (height: shell height, no post), the cell cathode is made of silicon carbon material, the end plate 4 is an aluminum end plate, two plates are added, the size is 102mm (length direction) ×3mm (thickness) ×105mm (height direction), the edges of the cross beams are perforated, the diameter of the perforated holes is 5mm, the number of the perforated holes of each cross beam 6 is 2, three cross beams are counted, the outer diameter of the die spring 2 is 20mm, the inner diameter of the perforated holes is 10mm, the diameter of the threaded rod 3 is 4mm, the bolts 1 are matched with the threaded rods 3, after the 7-string cell stack is arranged between the bolts 1 and the die spring 2, each two cross beams 6 are fixed at two ends of the cell through the threaded rods 3, the die spring 2 is 4, and the gaskets 4 are separated from the left-hand side view of the assembled cross beams by the die spring 2, and the die spring 2 is shown in the schematic diagram, as shown in the schematic diagram, and the schematic diagram 4 is shown in the assembled diagram.

Example 3

The third mode is adopted in this embodiment to assemble the group battery, and the group battery is 7 strings of group batteries, and group battery mechanical component includes single cell, end plate 4, screw rod 3, mould spring 2, bolt 1, gasket 5, the square frame 7 of the back-up, the single cell uses 50Ah square shell battery, and the battery size is 100mm (length) ×15mm (width) ×100mm (height: the height of the shell is equal to that of each end plate 4, no polar column is contained), the battery cathode is made of silicon carbon material, the end plates 4 are aluminum end plates, the total of the two end plates are 120mm (length direction) by 5mm (thickness) by 105mm (height direction), holes are formed in the edges of the end plates 4, the screws 3 penetrate through the holes, the diameters of the holes are 5mm, the number of the holes of each end plate 4 is 6, the outer diameter of each die spring 2 is 20mm, the inner diameter of each die spring is 10mm, the diameters of the screws 3 are 4mm, the bolts 1 are matched with the screws 3,

gaskets

5 and 7 are arranged between the bolts 1 and the die springs 2, after the two end plates 4 are stacked, the two end plates are fixed at two ends of a battery through the screws 3, the screws 3 penetrate through the end plates 4, each die springs 2 are arranged between the die springs 7, the die springs 2 are separated from the bolts 1 through the die springs 5, a front view is shown in fig. 5, the left view is shown in fig. 6, and the assembled front view is shown in fig. 6, and the assembled battery pack assembly structure is not shown.

The cycle performance data of the battery packs of the above three groups of examples are tested, a comparison group is designed at the same time, the design mode of the battery packs of the comparison group is designed according to the structure of the example 1, the mould spring in the example 1 is removed, a 2mm thick return frame is additionally arranged between the battery cells, and the test result is as follows:

the battery packs of examples 1/2/3 each had a larger cycle capacity retention than that of the battery packs of comparative examples, indicating that the swelling force of the battery packs assembled by the example methods was effectively released as the cycle proceeded, and the release of the swelling force improved the cycle performance of the battery packs.

The foregoing disclosure is illustrative of the present utility model and is not to be construed as limiting the scope of the utility model, which is defined by the appended claims.

Claims

1. The utility model provides a telescopic lithium battery group structure, its characterized in that, includes two parallel arrangement's holder, the holder is planar structure, two be equipped with the monocell between the holder, two connect through screw rod (3) between the holder, two are passed respectively at the both ends of screw rod (3) holder, the both ends of screw rod (3) are equipped with a spring assembly respectively, spring assembly is including bolt (1), gasket (5) and mould spring (2) that set up in order, mould spring (2) cover is established gasket (5) with between the holder on screw rod (3).

2. Telescopic lithium battery pack structure according to claim 1, characterized in that the clamping member is a rectangular end plate (4).

3. The telescopic lithium battery pack structure according to claim 2, wherein the screw rods (3) between the end plates (4) are disconnected to form disconnected ends, one screw rod (3) forms two disconnected ends, a return frame (7) is arranged between the two disconnected ends, the two disconnected ends penetrate through the return frame (7) and are arranged in the return frame (7), one spring assembly is connected to the two disconnected ends respectively, and a die spring (2) in each spring assembly is in contact with the return frame (7).

4. A telescopic lithium battery pack structure according to claim 3, characterized in that the number of screws (3) is 4-6.

5. The telescopic lithium battery pack structure according to claim 1, wherein the clamping members are cross beams (6), and the single cells are clamped between the cross beams (6).

6. The telescopic lithium battery pack structure according to claim 5, further comprising an end plate (4), wherein the end plate (4) is clamped between the cross beam (6) and the single cells.