A standing device for a lithium-ion soft-pack power battery after liquid injection and its standing method

Abstract

The present invention discloses a static device for a lithium-ion soft-pack power battery after liquid injection, which includes a static fixture; the static fixture includes a plurality of vertically distributed and horizontally spaced flapping splints; on the left and right sides of the static fixture, a fixed bracket is respectively arranged; at the front and rear ends of the upper part and the lower part of the static fixture and the fixed bracket, a connecting rod is respectively horizontally penetrated; at the upper part of each flapping splint, there is a battery accommodating notch with an open top for placing and supporting the battery after liquid injection. The left and right ends of the two connecting rods located at the upper part of the static fixture and the fixed bracket are respectively fixedly connected by a longitudinally distributed flapping pull rod. In addition, the present invention also discloses a method for statically placing a lithium-ion soft-pack power battery after liquid injection. The present invention can discharge the air bubbles inside the battery outward during the battery liquid injection process, effectively improving the infiltration performance of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing lithium-ion batteries, and particularly to a standing device for a lithium-ion soft-pack power battery after liquid injection and a standing method thereof. Background Art

[0002] With the increasingly serious energy crisis and environmental pollution problems globally, finding new energy sources for green and sustainable development has become the main development direction in the energy field. As a new energy vehicle that is energy-saving and environmentally friendly, electric vehicles are developing rapidly. Lithium-ion batteries have become one of the power sources that attract much attention due to their advantages such as high energy density, long cycle life, and green and pollution-free.

[0003] The electrolyte, separator, positive electrode material, and negative electrode material of a lithium-ion battery are collectively called the four major materials of a lithium-ion battery. The electrolyte of a lithium-ion battery is known as the "blood" of the lithium-ion battery, which plays a role in conducting lithium ions between the positive and negative electrodes of the battery and is insulated from electrons, thereby ensuring the smooth charge and discharge of the battery and having an important impact on various performances of the lithium-ion battery such as the operating temperature range, cycle efficiency, safety performance, rate performance, and storage performance. Among them, the wetting effect of the electrolyte plays a crucial role.

[0004] As an important step in the production of lithium-ion batteries - liquid injection, it is mainly completed in a drying room. Therefore, ensuring the wetting effect is of great significance for the cycle performance, storage performance, etc. of the battery. The wetting of the electrolyte on the electrode sheet involves the content of the contact of solid, liquid, and gas phases. When the electrolyte is injected into it, first, the electrolyte needs to expel the air inside the battery. After that, the electrolyte will adhere to the surface of the positive and negative active materials. Some of the electrolyte will enter between the positive electrode - separator - negative electrode through the separator of the wound core. As time goes by, there will be a phenomenon that the electrolyte wets the electrode sheet and the electrolyte in the separator wets the electrode sheet in the reverse direction. When the standing time reaches a certain extent, under the action of surface tension, the wetting of the electrode sheet reaches an equilibrium state. If there are air bubbles that fail to be discharged and remain on the surface of the positive and negative electrodes during this process, on the one hand, the wetting effect of the electrode sheet at the position of the bubbles will become worse, and on the other hand, it will cause lithium ions to be unable to pass through during the later charge and discharge process of the battery and accumulate on the surface of the electrode sheet to cause lithium plating, which will affect the safety performance of the product during long-term cyclic use. Therefore, it is crucial to completely expel the air bubbles from the inside of the battery during the wetting process.

[0005] However, there is currently no technology that can expel the air bubbles inside the battery during the liquid injection process of the battery, effectively improve the wetting performance of the battery, and improve the floating gas of the battery caused by poor wetting of the electrolyte. Summary of the Invention

[0006] The object of the present invention is to provide a standing device and a standing method for a lithium-ion soft-pack power battery after liquid injection, aiming at the technical defects existing in the prior art.

[0007] To this end, the present invention provides a standing device for a lithium-ion soft-pack power battery after liquid injection, which includes a horizontally distributed standing fixture;

[0008] The standing fixture includes a plurality of vertically distributed and horizontally spaced flapping splints;

[0009] On the left and right sides of the standing fixture, a fixed bracket is respectively provided;

[0010] At the front and rear ends of the upper part and the lower part of the standing fixture and the fixed bracket, a connecting rod passes through horizontally;

[0011] For the connecting rod located at the lower part of the standing fixture, on the outer wall of the connecting rod between any two adjacent flapping splints, a telescopic spring is sleeved;

[0012] Moreover, for the connecting rod located at the lower part of the standing fixture, on the outer wall of the position between the leftmost flapping splint and the adjacent fixed bracket, and on the outer wall of the position between the rightmost flapping splint of the standing fixture and the adjacent fixed bracket, telescopic springs are sleeved;

[0013] On the upper part of each flapping splint, there is a battery accommodation notch with an open top for placing and supporting the battery after liquid injection.

[0014] At the left and right ends of the two connecting rods located at the upper part of the standing fixture and the fixed bracket, they are fixedly connected by a longitudinally distributed flapping pull rod respectively;

[0015] At the ends of the two connecting rods located on the upper side of the standing fixture in the same direction, they are respectively connected to the output ends of a telescopic cylinder.

[0016] Among them, the bottom surface of the fixed bracket is fixed on an external working platform.

[0017] Among them, the two connecting rods located at the lower part of the standing fixture and the fixed bracket are directly below the two connecting rods located at the upper part of the standing fixture and the fixed bracket.

[0018] Among them, the standing fixture and the fixed bracket are provided with reserved horizontally penetrating holes for the connecting rods to pass through;

[0019] Among them, the aperture of the horizontally penetrating hole on the fixed bracket is larger than the diameter of the connecting rod, and the two are in clearance fit;

[0020] Among them, the connecting rod is fixedly connected to each flapping splint, and the connecting rod and the horizontally penetrating hole on the flapping splint are in interference fit.

[0021] In addition, the present invention also provides a static placement method using the static placement device for lithium-ion soft-pack power batteries after liquid injection as described above, including the following steps:

[0022] In the first step, open the opening at the top of the battery airbag that needs to be injected with liquid and has a core package pre-placed inside, and then perform liquid injection to obtain a battery after liquid injection.

[0023] In the second step, place the battery after liquid injection into the static placement device for lithium-ion soft-pack power batteries after liquid injection, and then place this static placement device for lithium-ion soft-pack power batteries after liquid injection into the three vacuum chambers of the first vacuum chamber, the second vacuum chamber, and the third vacuum chamber in sequence. And after placing the static placement device for lithium-ion soft-pack power batteries after liquid injection into any one of the vacuum chambers each time, perform a vacuum static placement operation in real time, and while performing the vacuum static placement operation, perform a patting operation on the battery after liquid injection in real time through the static placement device for lithium-ion soft-pack power batteries after liquid injection in the vacuum chamber.

[0024] Among them, the first vacuum chamber, the second vacuum chamber, and the third vacuum chamber are three independent cavities;

[0025] The vacuum degrees of the first vacuum chamber, the second vacuum chamber, and the third vacuum chamber show an increasing trend.

[0026] Among them, in the second step, the time for the vacuum static placement operation is 10 to 15 minutes.

[0027] Among them, in the second step, the vacuum degrees of the first vacuum chamber, the second vacuum chamber, and the third vacuum chamber are -30 MPa, -50 MPa, and -80 MPa respectively.

[0028] As can be seen from the technical solutions provided by the present invention above, compared with the prior art, the present invention provides a static placement device for lithium-ion soft-pack power batteries after liquid injection and its static placement method, which can discharge the air bubbles inside the battery outward during the battery liquid injection process, effectively improve the infiltration performance of the battery, and improve the floating gas of the battery caused by poor infiltration of the electrolyte, and has great practical significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flowchart of a static placement method for lithium-ion soft-pack power batteries provided by the present invention;

[0030] Figure 2 It is a top view of a static placement device for lithium-ion soft-pack power batteries provided by the present invention;

[0031] Figure 3 It is a side view of the positional relationship between the patting splint 2 and the connecting rod 1 in a static placement device for lithium-ion soft-pack power batteries provided by the present invention;

[0032] Figure 4A static device for a lithium-ion soft-pack power battery after liquid injection provided by the present invention, a schematic diagram of the electrolyte distribution inside the battery before patting one battery;

[0033] Figure 5 A schematic diagram of the structure when two sets of static devices for a lithium-ion soft-pack power battery after liquid injection provided by the present invention are installed on the top of a base platform;

[0034] Figure 6 A front view of a static device for a lithium-ion soft-pack power battery after liquid injection provided by the present invention;

[0035] In the figure, 1 is a connecting rod, 2 is a patting clamping plate, 3 is a static fixture, 4 is a telescopic spring, and 5 is a pulling rod for patting;

[0036] 10 is a battery, 30 is a fixing bracket, and 20 is a battery accommodation notch;

[0037] 101 is a push-pull connection block. Specific embodiments

[0038] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0039] See Figures 1 to 6 , the present invention provides a static method for a lithium-ion soft-pack power battery after liquid injection, including the following steps:

[0040] In the first step, the battery air bag that needs to be injected with liquid and pre-loaded with a core package is opened at its top opening, and then liquid injection is carried out to obtain a battery after liquid injection;

[0041] In the second step, the battery after liquid injection is placed in a static device for a battery after liquid injection, and then the static device for a battery after liquid injection is successively placed in three vacuum chambers, namely the first vacuum chamber, the second vacuum chamber, and the third vacuum chamber. And each time the static device for a battery after liquid injection is placed in any one of the vacuum chambers, a vacuum static operation is carried out in real time, and while the vacuum static operation is being carried out, the battery after liquid injection is patted in real time through the static device for a battery after liquid injection in the vacuum chamber.

[0042] It should be noted that for the present invention, each time a vacuum static operation is carried out, the battery static in the vacuum chamber is patted. The patting can make the electrolyte inside the battery move sufficiently, so that tiny bubbles overflow from the electrolyte under the action of the patting force, and then are pumped out under the vacuum state, so as to ensure that the tiny bubbles inside the battery can also be discharged, improving the infiltration performance of the battery.

[0043] In the present invention, the first vacuum chamber, the second vacuum chamber, and the third vacuum chamber are three independent cavities, and each cavity has a separate vacuum pumping system;

[0044] The vacuum degrees of the first vacuum chamber, the second vacuum chamber, and the third vacuum chamber show an increasing trend. Therefore, the static vacuum degree of the battery after liquid injection flows successively from bottom to top.

[0045] In the present invention, in the second step, the time for the vacuum pumping and static operation is preferably 10 to 15 minutes.

[0046] Specifically, the vacuum degrees of the first vacuum chamber, the second vacuum chamber, and the third vacuum chamber are preferably -30 MPa, -50 MPa, and -80 MPa respectively. Under these parameters, it can not only ensure that large air bubbles can be pumped out, but also ensure that the electrolyte will not be pumped out. The vacuum pumping time for each vacuum chamber can be set between 10 and 15 minutes. At the same time, the flapping splints in the vacuum chamber are accompanied by the action of flapping the battery, and the flapping frequency of the flapping splints can be set to 5 times per minute. In this way, the tiny air bubbles at the bottom of the battery can effectively flow out after being flapped.

[0047] For the present invention, in the first step, the static device for the battery after liquid injection provided by the present invention has a specific structure as follows: it includes a static fixture 3 distributed horizontally;

[0048] The static fixture 3 includes a plurality of flapping splints 2 vertically distributed and horizontally spaced (such as thirty-one shown in the figure);

[0049] On the left and right sides of the static fixture 3, a fixed bracket 30 is respectively provided;

[0050] A connecting rod 1 horizontally penetrates through the front and rear ends of the upper part and the front and rear ends of the lower part of the static fixture 3 and the fixed bracket 30 respectively;

[0051] It should be noted that the bottom surface of the fixed bracket 30 is fixed on the external working platform.

[0052] For the connecting rod 1 located at the lower part of the static fixture 3, a telescopic spring 4 is sleeved on the outer wall of the connecting rod 1 between any two adjacent flapping splints 2;

[0053] Moreover, for the connecting rod 1 located at the lower part of the static fixture 3, telescopic springs 4 are sleeved on the outer walls at the positions between the leftmost flapping splint 2 and the adjacent fixed bracket 30, and at the positions between the rightmost flapping splint 2 of the static fixture 3 and the adjacent fixed bracket 30;

[0054] The upper part of each flapping splint 2 has a battery receiving notch 20 with an open top for placing and supporting the battery after liquid injection.

[0055] The left and right ends of the two connecting rods 1 located on the upper part of the static clamp 3 and the fixed bracket 30 are respectively fixedly connected by a longitudinally distributed slapping rod 5 (for example, threaded connection or clamping or other fixed connection methods);

[0056] It should be noted that the two connecting rods 1 located at the lower part of the static clamp 3 and the fixed bracket 30 are located directly below the two connecting rods 1 located at the upper part of the static clamp 3 and the fixed bracket 30 .

[0057] The right end of the connecting rod 1 located on the upper part of the static clamp 3 (specifically, it can be any one of the two, the specific position is Figure 5 The push-pull connecting block 101 shown in the figure has a through hole in the center of the circle), which is connected to the output end of a telescopic cylinder. Driven by the cylinder, it moves laterally to the left and right, and then the slapping pull rod 5 moves together, and then the upper part of the outer splint on the right side of the static clamp 3 is squeezed and pushed laterally, thereby pushing the upper part of multiple slapping splints 2. At this time, considering that the outer wall of the connecting rod 1 located at the lower part of the static clamp 3 is sleeved with a telescopic spring 4, and then under the action of the telescopic spring, the lower part of multiple slapping splints 2 is pushed by the rebound force of the spring to form a shake (the slapping splint 2 does not have the elastic force of the telescopic spring). Therefore, each slapping splint 2 not only shakes the battery placed on it, but also pushes and slaps the battery on the adjacent slapping splint 2 located in the moving direction, thereby achieving the effect of swaying and slapping the lower part (bottom) of the battery after liquid injection back and forth.

[0058] It should be noted that Figure 5 Two sets of a post-filling static device for a lithium-ion soft-pack power battery provided by the present invention are shown, which are installed on the top of a base platform.

[0059] In the present invention, it should be noted that the stationary fixture 3 and the fixing bracket 30 have reserved transverse through holes for passing the connecting rod 1 through;

[0060] The diameter of the transverse through hole on the fixing bracket 30 is larger than the diameter of the connecting rod 1 , and the two are clearance-matched, so that the connecting rod 1 can slide transversely in the transverse through hole on the fixing bracket 30 under the drive of external force.

[0061] Among them, the connecting rod 1 is fixedly connected to each flapping splint 2, and the transverse through holes on the connecting rod 1 and the flapping splint 2 can be interference fit.

[0062] In the present invention, it should be noted that the flapping splint 2 used for flapping in the battery standing device after the battery is filled with liquid in the standing cavity is preferably sized to completely cover at least two-thirds of the battery body (for example, two-thirds of the battery body is placed, such as the middle and lower parts, for example, two-thirds of the battery can be placed in the battery receiving notch 20), so as to ensure the flapping effect.

[0063] It should be noted that the traditional liquid injection method is generally as follows: the battery air bag is opened for liquid injection or the battery is evacuated and then liquid injection is carried out, and then vacuum sealing is carried out. However, for the traditional liquid injection method, when liquid injection is carried out after evacuation, there are problems such as difficult opening of the air bag and easy overflow of the electrolyte. Therefore, the traditional normal pressure liquid injection method used in the present invention places the battery after liquid injection into the standing tooling designed in the present invention (i.e., the battery standing device after liquid injection).

[0064] After the battery is filled with liquid, as Figure 4 shown, the electrolyte 11 accumulates at the bottom of the battery 10, and only the part of the battery core package 12 close to the bottom can be immersed in the electrolyte 11. Therefore, the present invention increases the way of flapping and shaking the bottom of the battery (as Figure 4 shown by the arrow), so that the electrolyte can move upward under the action of external force, so that the position of the core package close to the upper part can also contact the electrolyte, increasing the wetting area.

[0065] In addition, through the flapping of the flapping splint, the tiny bubbles hidden between the electrolyte and the core package can move under the external force of the flapping splint, and then are discharged from the inside of the battery through the buoyancy of the electrolyte. While the flapping operation is carried out, the bubbles are pumped out under the condition of evacuation.

[0066] For the present invention, specifically, three vacuum cavities with different vacuum degrees are used for three-step vacuum standing, and the vacuum degree increases step by step. First, preliminary exhaust is carried out at -30 Kpa, then secondary exhaust is carried out at -50 Kpa, and finally final exhaust is carried out at -80 Kpa. By cooperating with the flapping method, the purpose of discharging the gas in the electrolyte in the battery and improving the wetting effect of the electrolyte is finally achieved, so as to ensure that the electrolyte inside the battery is fully wetted and the performance of the battery is improved.

[0067] It should be noted that after the injection of electrolyte, there are tiny bubbles inside the soft-pack battery. If directly evacuated and sealed, the tiny bubbles may not be able to escape due to the resistance of the liquid, resulting in incomplete exhaust. Therefore, for the present invention, three vacuum chambers are added before sealing after the injection of electrolyte. Each vacuum chamber is set with different vacuum values, and the vacuum values gradually increase in a stepped manner, which is conducive to the up-and-down movement of the electrolyte under vacuum. In addition, self-sliding flapping clamps are added to each vacuum chamber. When the vacuum is evacuated and the battery is left stationary each time, the batteries stationary in the vacuum chamber are flapped. The flapping can make the electrolyte inside the battery move fully, so that the tiny bubbles overflow from the electrolyte under the action of the flapping force, and then are evacuated under the vacuum state, thus ensuring that the tiny bubbles inside the battery can also be discharged and improving the infiltration performance of the electrolyte inside the battery.

[0068] For the present invention, it mainly focuses on the setting of the vacuum evacuation parameters and the stationary mode, including the design of the clamps during vacuum evacuation. The vacuum evacuation stationary mode and parameter design are mainly aimed at improving the injection and infiltration effect and improving the floating gas of the battery caused by poor infiltration.

[0069] In order to more clearly understand the technical solution of the present invention, the following will be described in conjunction with specific embodiments.

[0070] Put 32 batteries after the injection of electrolyte into the stationary fixture, then place the stationary fixture into the interior of a vacuum chamber, and then evacuate the vacuum. Under the vacuum pressure-holding state, an internal cylinder inside the vacuum chamber is used to pull the rod for flapping, so that each flapping clamp regularly flaps the battery under the action of the telescopic spring. It is generally recommended to flap 10 times, and then end the vacuum. Enter the next vacuum state and repeat the flapping. A total of three stationary operations are performed to complete all the flapping. To meet the production capacity, it is recommended that the three vacuum chambers operate separately. According to the production capacity requirements, the number of stationary batteries can be adjusted.

[0071] In summary, compared with the prior art, a stationary device and its stationary method for a lithium-ion soft-pack power battery after the injection of electrolyte provided by the present invention can discharge the bubbles inside the battery during the injection process of the battery, effectively improve the infiltration performance of the battery, and improve the floating gas of the battery caused by poor infiltration of the electrolyte, which has great practical significance.

[0072] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A static device for a lithium-ion soft-pack power battery after liquid injection, characterized in that, it includes a horizontally distributed static fixture (3); the static fixture (3) includes a plurality of vertically distributed and horizontally spaced flapping splints (2); on the left and right sides of the static fixture (3), a fixed bracket (30) is respectively provided; at the front and rear ends of the upper and lower parts of the static fixture (3) and the fixed bracket (30), a connecting rod (1) horizontally penetrates through respectively; for the connecting rod (1) located at the lower part of the static fixture 3, on the outer wall of the connecting rod (1) between any two adjacent flapping splints (2), a telescopic spring (4) is sleeved; at the upper part of each flapping splint (2), there is a battery accommodation notch (20) with an open top for placing and supporting the battery after liquid injection; at the left and right ends of the two connecting rods (1) located at the upper part of the static fixture (3) and the fixed bracket (30), they are fixedly connected respectively through a longitudinally distributed flapping pull rod (5); at the same-direction ends of the two connecting rods (1) located on the upper side of the static fixture (3), they are respectively connected to the output ends of a telescopic cylinder; the bottom surface of the fixed bracket (30) is fixed on an external working platform; the static fixture (3) and the fixed bracket (30) have reserved horizontally penetrating holes for the connecting rod (1) to penetrate through.

2. The device according to claim 1, characterized in that, for the connecting rod (1) located at the lower part of the static fixture 3, on the outer wall of its position between the leftmost flapping splint (2) and the adjacent fixed bracket (30), and on the outer wall of its position between the rightmost flapping splint (2) of the static fixture (3) and the adjacent fixed bracket (30), telescopic springs (4) are sleeved.

3. The device according to claim 1, characterized in that, the two connecting rods (1) located at the lower part of the static fixture (3) and the fixed bracket (30) are directly below the two connecting rods (1) located at the upper part of the static fixture (3) and the fixed bracket (30).

4. The device according to claim 1, characterized in that, wherein, the aperture of the horizontally penetrating hole on the fixed bracket (30) is larger than the diameter of the connecting rod (1), and the two are in clearance fit; wherein, the connecting rod (1) is fixedly connected to each flapping splint (2), and the connecting rod (1) and the horizontally penetrating hole on the flapping splint (2) are in interference fit.

5. A static method using the static device for a lithium-ion soft-pack power battery after liquid injection according to any one of claims 1 to 4, characterized in that, it includes the following steps: The first step, open the opening at the top of the battery air bag that needs to be injected with liquid and has a core package pre-placed in it, and then perform liquid injection to obtain the battery after liquid injection. The second step, place the battery after liquid injection into the static device for the battery after liquid injection, and then place this static device for the battery after liquid injection into the three vacuum chambers of the first vacuum chamber, the second vacuum chamber, and the third vacuum chamber in sequence. And after placing the static device for the battery after liquid injection into any one of the vacuum chambers each time, perform a vacuum static operation in real time, and while performing the vacuum static operation, perform a flapping operation on the battery after liquid injection in real time through the static device for the battery after liquid injection in the vacuum chamber.

6. The standing method according to claim 5, wherein, the first vacuum chamber, the second vacuum chamber and the third vacuum chamber are three independent chambers; the vacuum degrees of the first vacuum chamber, the second vacuum chamber and the third vacuum chamber show an increasing trend.

7. The standing method according to claim 5, wherein, in the second step, the time for the vacuum pumping and standing operation is 10 to 15 minutes.

8. The standing method according to claim 5, wherein, in the second step, the vacuum degrees of the first vacuum chamber, the second vacuum chamber and the third vacuum chamber are -30 MPa, -50 MPa and -80 MPa respectively.

Images