Pouch lithium battery electrolyte infiltration device and method

Abstract

The application relates to the technical field of lithium batteries, and provides a soft package lithium battery electrolyte infiltration device and method.The soft package lithium battery electrolyte infiltration device comprises an ultrasonic system, a guide rod, a clamp and a pair of clamping plates.The first end of the guide rod is connected with the ultrasonic system, and the guide rod is used for transmitting ultrasonic waves.The soft package lithium battery is clamped between the pair of clamping plates, and the second end of the guide rod is connected with one of the clamping plates.The soft package lithium battery electrolyte infiltration device provided by the application can increase the movement of electrolyte in the soft package lithium battery by setting the ultrasonic system, the guide rod and the clamp, reduce the wetting angle of the electrolyte and the solid interface, quickly achieve good infiltration effect, and shorten the electrolyte infiltration time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium battery, in particular to a soft package lithium battery electrolyte infiltration device and a soft package lithium battery electrolyte infiltration method. BACKGROUND

[0002] The electrolyte is an ion conductor between the positive and negative electrodes in the lithium ion battery, and is responsible for the back-and-forth transmission of lithium ions between the positive and negative electrodes during the charging and discharging process of the battery. Generally, the lithium ion battery needs to be placed for a long time after the liquid injection process to ensure that the electrolyte is uniformly diffused inside the battery, so as to fully infiltrate the positive and negative active materials and the separator inside the battery. If the standing time is insufficient, the electrolyte infiltration effect is poor, and the lithium ion transmission path is far, which will hinder the transmission of lithium ions between the positive and negative electrodes, and the electrode plate not in contact with the electrolyte will not participate in the electrochemical reaction in the battery, and a stable solid electrolyte protective film cannot be formed on the surface of the electrode active material. At the same time, the battery interface impedance increases, affecting the rate, cycle and safety performance of the battery. If the standing time is too long, it will directly affect the production efficiency of the lithium ion battery.

[0003] In order to solve the problem of electrode plate infiltration in the prior art, the common methods are to increase the normal temperature infiltration time, but this method generally requires a long standing time (20-50h). The method of increasing the infiltration temperature is used for infiltration, but long-term high-temperature standing will cause an increase in electrolyte side reactions and deterioration of battery performance. Multiple liquid injection or vacuum negative pressure-ambient pressure-high pressure multi-stage circulation operation is used after liquid injection to increase the contact opportunity of electrolyte with electrodes and separators, but this method generally has a complex process, and the battery is in an open state for a long time, increasing the electrolyte water absorption rate and electrolyte evaporation rate. There is also a method of placing the battery in the water-filled ultrasonic cleaning device after liquid injection, and using the ultrasonic cleaning device for electrolyte infiltration. This method has high requirements for the purity of the medium water, is easy to cause short circuit of the battery, and the effect of the ultrasonic cleaning device is more on the interface between the medium water and the battery shell, greatly reducing the effect of electrolyte infiltration inside the battery. SUMMARY

[0004] The present application provides a soft package lithium battery electrolyte infiltration device and a soft package lithium battery electrolyte infiltration method to solve the defect of long lithium battery electrolyte infiltration time in the prior art.

[0005] The present application provides a soft package lithium battery electrolyte infiltration device, comprising: an ultrasonic system; a guide rod, the first end of the guide rod is connected with the ultrasonic system, and the guide rod is used for transmitting ultrasonic waves; a clamp, the clamp comprises a pair of clamping plates, a soft package lithium battery is clamped between the pair of clamping plates, and the second end of the guide rod is connected with one of the clamping plates.

[0006] The utility model provides a kind of soft package lithium battery electrolyte infiltration device provided by the utility model, the first end of the guide rod is telescopically connected with the ultrasonic system, the second end of the guide rod is telescopically connected with a clamping plate, to adjust the distance between a pair of clamping plates.

[0007] The utility model provides a kind of soft package lithium battery electrolyte infiltration device provided by the utility model further includes stepper controller, the stepper controller is connected with the guide rod, for adjusting the distance between the ultrasonic system and the fixture.

[0008] The utility model provides a kind of soft package lithium battery electrolyte infiltration device provided by the utility model further includes stress detection plate, the stress detection plate is clamped in a pair of clamping plates, and is overlaid with the soft package lithium battery, and the stress detection plate is used to detect the clamping force of the fixture to the soft package lithium battery.

[0009] The utility model provides a kind of soft package lithium battery electrolyte infiltration device provided by the utility model, the frequency of the ultrasonic system is 10-100kHz, and the working time length of the ultrasonic system is 5-120min.

[0010] The utility model provides a kind of soft package lithium battery electrolyte infiltration device provided by the utility model further includes fixed component, and the fixed component includes: fixed support, the fixed support is connected with the ultrasonic system by fixed part;Base, the base is connected with the fixed support.

[0011] The utility model further provides a kind of method for infiltration using the soft package lithium battery electrolyte infiltration device described above, including: the soft package lithium battery is clamped in a pair of clamping plates;The working time length of the ultrasonic system is controlled to meet preset threshold value, to make the ultrasonic wave generated by the ultrasonic system act on the soft package lithium battery, to the soft package lithium battery is infiltrated.

[0012] The utility model provides a kind of soft package lithium battery electrolyte infiltration method provided by the utility model, and the method further includes: the working mode of the ultrasonic system is controlled to be continuous working mode or intermittent working mode.

[0013] The utility model provides a kind of soft package lithium battery electrolyte infiltration method provided by the utility model, and the step that the working mode of the ultrasonic system is controlled to be intermittent working mode further includes: the running time length and stop time length of the ultrasonic system are equal each time.

[0014] The method for infiltrating electrolyte of a soft package lithium battery according to the application further comprises: before the step of clamping the soft package lithium battery in a pair of clamping plates, placing a dry battery cell in an aluminum plastic film, packaging three sides of the aluminum plastic film, leaving one side open as a liquid injection port, and drying the dry battery cell; injecting electrolyte into the dry battery cell through the liquid injection port, and closing the liquid injection port after the dry battery cell is vacuumed for a preset time length.

[0015] The device for infiltrating electrolyte of a soft package lithium battery according to the application can increase the movement of electrolyte in the soft package lithium battery by using ultrasonic vibration, reduce the wetting angle of the electrolyte and the solid interface, and thus quickly achieve a good infiltration effect and shorten the infiltration time of the electrolyte. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0017] Figure 1 FIG. 1 is a structural schematic diagram of the device for infiltrating electrolyte of a soft package lithium battery according to the application;

[0018] Reference signs:

[0019] 10: ultrasonic system; 20: guide rod; 30: clamp; 31: upper clamping plate; 32: lower clamping plate; 40: stress detection plate; 51: fixed support; 52: base; 53: fixing piece; 60: step controller; 100: soft package lithium battery. DETAILED DESCRIPTION

[0020] In order to make the objects, technical solutions and advantages of the application clearer, the technical solutions in the application will be described clearly and completely below with reference to the drawings in the application. Obviously, the described embodiments are some embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative effort belong to the protection scope of the application.

[0021] The features of the terms "first" and "second" in the specification and claims of the application can be explicitly or implicitly included one or more features. In the description of the application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0022] The following will be described with reference to the drawings. Figure 1The application discloses a soft package lithium battery electrolyte infiltration device and a soft package lithium battery electrolyte infiltration method.

[0023] As shown in the drawings, Figure 1 In one embodiment of the application, the soft package lithium battery electrolyte infiltration device comprises an ultrasonic system 10, a guide rod 20 and a clamp 30. The first end of the guide rod 20 is connected with the ultrasonic system 10, and the second end of the guide rod 20 is connected with the clamp 30. The guide rod 20 is used for transmitting the ultrasonic wave generated by the ultrasonic system 10. The clamp 30 comprises a pair of clamping plates, and the soft package lithium battery 100 is clamped between the pair of clamping plates. The second end of the guide rod 20 is connected with one clamping plate.

[0024] Specifically, the clamp 30 comprises an upper clamping plate 31 and a lower clamping plate 32. The soft package lithium battery 100 is clamped between the upper clamping plate 31 and the lower clamping plate 32. After the ultrasonic system 10 is turned on, the ultrasonic wave generated by the ultrasonic system 10 is transmitted to the soft package lithium battery 100 through the guide rod 20. The ultrasonic vibration can promote the movement of the electrolyte in the soft package lithium battery 100. Meanwhile, the cavitation effect of the ultrasonic wave can also reduce the wetting angle between the electrolyte and the electrode plate and the diaphragm, so that the wettability between the electrolyte and the electrode and the diaphragm is improved, thereby the electrolyte can be spread better and quickly reach a good infiltration effect, thereby the infiltration time is shortened.

[0025] Optionally, in the embodiment of the application, the frequency of the ultrasonic system is 10-100 kHz.

[0026] The soft package lithium battery electrolyte infiltration device provided by the embodiment of the application can increase the movement of the electrolyte in the soft package lithium battery by using ultrasonic vibration, reduce the wetting angle between the electrolyte and the solid interface, quickly reach a good infiltration effect, and shorten the electrolyte infiltration time.

[0027] In one embodiment of the application, the first end of the guide rod 20 is telescopically connected with the ultrasonic system 10, and the second end of the guide rod 20 is telescopically connected with the upper clamping plate 31, so as to adjust the distance between the upper clamping plate 31 and the lower clamping plate 32.

[0028] Specifically, by adjusting the telescopic length of the guide rod 20, the distance between the ultrasonic system 10 and the upper clamping plate 31 can be adjusted, and then the distance between the upper clamping plate 31 and the lower clamping plate 32 is adjusted, so as to adjust the clamping force of the clamp 30. It should be noted that in the embodiment of the application, the clamping force of the clamp 30 should not be too large. The main function of the clamp 30 is to make the two end surfaces of the soft package lithium battery 100 contact with the surfaces of the clamping plates, so as to make the surface of the soft package lithium battery 100 flat, and then the ultrasonic wave can be uniformly transmitted into the soft package lithium battery 100.

[0029] Optionally, in an embodiment of the present application, the first end of the guide rod 20 is threadedly connected with the ultrasonic system 10, and the second end of the guide rod 20 is threadedly connected with the upper clamping plate 31, so as to adjust the distance between the upper clamping plate 31 and the lower clamping plate 32.

[0030] Further, as shown in the drawings, Figure 1 in an embodiment of the present application, the soft-pack lithium battery electrolyte infiltration device further comprises a stress detection plate 40. The stress detection plate 40 is clamped in the pair of clamping plates and is stacked with the soft-pack lithium battery 100. The stress detection plate 40 is used to detect the clamping force of the clamp 30 on the soft-pack lithium battery 100.

[0031] Specifically, the stress detection plate 40 is stacked on the lower clamping plate 32, the soft-pack lithium battery 100 is stacked on the stress detection plate 40, and the stress detection plate 40 is used to detect the force of the upper clamping plate 31 on the soft-pack lithium battery 100. In an embodiment of the present application, the clamping force of the clamp 30 should be less than 0.10.1 Mpa, so as to prevent the soft-pack lithium battery 100 from being broken due to excessive clamping force.

[0032] As shown in the drawings, Figure 1 in an embodiment of the present application, the soft-pack lithium battery electrolyte infiltration device further comprises a step controller 60. The step controller 60 is connected with the guide rod 20 and is used to adjust the distance between the ultrasonic system 10 and the clamp 30.

[0033] Specifically, the step controller 60 can drive the guide rod 20 to rotate, so as to adjust the distance between the ultrasonic system 10 and the clamp 30, and thus adjust the distance between the upper clamping plate 31 and the lower clamping plate 32.

[0034] As shown in the drawings, Figure 1 in an embodiment of the present application, the soft-pack lithium battery electrolyte infiltration device further comprises a fixing assembly. The fixing assembly comprises a fixing support 51, a base 52 and a fixing piece 53. The fixing support 51 is connected with the acting end of the ultrasonic system 10 through the fixing piece 53, so as to fix the acting end of the ultrasonic system 10. The fixing support 51 is connected with the base 52, so as to fix the fixing support 51.

[0035] The embodiment of the present application also provides a method for infiltrating electrolyte of a soft-pack lithium battery, which specifically comprises the following steps:

[0036] Step 101: Clamping the soft-pack lithium battery 100 in the pair of clamping plates.

[0037] Specifically, clamping the soft-pack lithium battery 100 in the pair of clamping plates can make the two surfaces of the soft-pack lithium battery 100 in contact with the upper clamping plate 31 and the lower clamping plate 32 flat, so that the ultrasonic wave can be uniformly transmitted into the soft-pack lithium battery 100.

[0038] Step 102: control the working time length of the ultrasonic system 10 to meet a preset threshold, so that the ultrasonic wave generated by the ultrasonic system 10 acts on the soft package lithium battery 100 to infiltrate the soft package lithium battery 100.

[0039] Specifically, after the soft package lithium battery 100 is clamped, the ultrasonic system 10 is started, and the ultrasonic wave is transmitted to the soft package lithium battery 100 through the guide rod 20 and the clamp 30. The ultrasonic vibration can increase the movement of the electrolyte in the soft package lithium battery 100, and the cavitation effect of the ultrasonic wave can reduce the wetting angle between the electrolyte and the electrode plate and the diaphragm, so that the wettability between the electrolyte and the electrode and the diaphragm is good, so that the electrolyte can be better spread and quickly achieve good infiltration effect, shorten the infiltration time of the electrolyte. Further, in the embodiment of the present application, the working time length of the ultrasonic system 10 should meet a preset threshold, wherein the preset threshold is 5-120min.

[0040] The soft package lithium battery electrolyte infiltration method provided by the embodiment of the present application utilizes ultrasonic vibration to increase the movement of the electrolyte in the soft package lithium battery, reduce the wetting angle between the electrolyte and the solid interface, and thus quickly achieve good infiltration effect and shorten the infiltration time of the electrolyte.

[0041] Further, in the embodiment of the present application, the method for infiltrating electrolyte of the soft package lithium battery further comprises the following steps: controlling the working mode of the ultrasonic system 10 to be continuous working mode or intermittent working mode.

[0042] Specifically, the continuous working mode is that the ultrasonic system 10 works continuously for a certain time length; the intermittent working mode is that the ultrasonic system 10 works for a certain time length and then stops, and then works and stops again after a certain time length, and so on.

[0043] Further, when the intermittent working mode is adopted, the running time length and the stopping time length of the ultrasonic system 10 are equal each time. For example, running 1s and stopping 1s, or running 2s and stopping 2s, etc.

[0044] In an embodiment of the present application, before the step of clamping the soft package lithium battery 100 in a pair of clamping plates, the method for infiltrating electrolyte of the soft package lithium battery further comprises: packaging the dry cell into an aluminum plastic film, packaging three sides of the aluminum plastic film, leaving one side open as a liquid injection port, and drying the dry cell; injecting electrolyte into the dry cell through the liquid injection port, and closing the liquid injection port after the dry cell is vacuumed for a preset time length.

[0045] Specifically, the dry cell is produced according to a conventional production process of the soft package lithium battery, and the dry cell is loaded into an aluminum plastic film. Three sides of the aluminum plastic film are heat-pressed and packaged, and the remaining one side is left as an air bag. The air bag end opening is used as a liquid injection port. The aluminum plastic film is placed in a vacuum oven to dry the dry cell. After drying, a certain amount of electrolyte is injected into the dried dry cell by using a one-time injection method. The soft package lithium battery is vacuumed for about 1 min, and the air bag end of the soft package lithium battery is sealed.

[0046] At room temperature and normal pressure, the soft package lithium battery is placed in the clamp 30 for ultrasonic assisted infiltration. After the infiltration operation is completed, the soft package lithium battery is pre-charged, formed, sealed, and related electrochemical performance tests are performed. It should be noted that in the embodiments of the present application, all cell systems, electrode designs, electrolyte formulations, and electrolyte injection amounts are the same. The pre-charging, formation, and battery test system after the electrolyte infiltration of the soft package lithium battery are also the same, so they are not described here.

[0047] The soft package lithium battery electrolyte infiltration device and method provided by the embodiments of the present application are used to perform the following tests by adjusting the frequency of the ultrasonic system 10, the working time of the ultrasonic system 10, and the working mode of the ultrasonic system 10.

[0048] Example 1

[0049] After the battery is injected, the battery is clamped by the upper guide plate and the lower pad plate, and the stress is 0.02 MPa. The soft package battery is acted on by using an ultrasonic frequency of 20 kHz, and the action time is 60 min. The ultrasonic application mode is open for 2 s and stop for 2 s.

[0050] Example 2

[0051] After the battery is injected, the battery is clamped by the upper guide plate and the lower pad plate, and the stress is 0.02 MPa. The soft package battery is acted on by using an ultrasonic frequency of 40 kHz, and the action time is 30 min. The ultrasonic application mode is open for 3 s and stop for 3 s.

[0052] Example 3

[0053] After the battery is injected, the battery is clamped by the upper guide plate and the lower pad plate, and the stress is 0.01 MPa. The soft package battery is acted on by using an ultrasonic frequency of 100 kHz, and the action time is 30 min. The ultrasonic application mode is open for 1 s and stop for 1 s.

[0054] Example 4

[0055] After the battery is injected, the battery is clamped by the upper guide plate and the lower pad plate, and the stress is 0.08 MPa. The soft package battery is acted on by using an ultrasonic frequency of 50 kHz, and the action time is 20 min. The ultrasonic application mode is continuous.

[0056] Example 5

[0057] After the battery is injected with electrolyte, the battery is clamped by the upper guide plate and the lower pad plate with a stress of 0.02 MPa; a 30 kHz ultrasonic frequency is used to act on the soft package battery, and the action time is 30 min; the ultrasonic application mode is continuous application.

[0058] Example 6

[0059] After the battery is injected with electrolyte, the battery is clamped by the upper guide plate and the lower pad plate with a stress of 0.02 MPa; a 10 kHz ultrasonic frequency is used to act on the soft package battery, and the action time is 60 min; the ultrasonic application mode is continuous application.

[0060] The following test was carried out using the infiltration method in the prior art as a comparative example.

[0061] Comparative Example 1

[0062] After the battery is injected with electrolyte, the battery is clamped by the upper guide plate and the lower pad plate with a stress of 0.02 MPa;

[0063] The electrolyte infiltration standing time is 60 min.

[0064] No ultrasonic wave is applied.

[0065] Comparative Example 2

[0066] After the battery is injected with electrolyte, it is naturally placed in a normal temperature and pressure environment for 48 h

[0067] No upper guide plate and lower pad plate clamping is used.

[0068] No ultrasonic wave is applied.

[0069] Comparative Example 3

[0070] After the battery is injected with electrolyte, the battery is clamped by the upper guide plate and the lower pad plate with a stress of 0.02 MPa; the electrolyte infiltration standing time is 48 h;

[0071] No ultrasonic wave is applied.

[0072] Comparative Example 4

[0073] After the battery is injected with electrolyte, the battery is placed in an ultrasonic cleaning device;

[0074] A 20 kHz ultrasonic frequency is used to act on the soft package lithium battery, and the action time is 60 min; the ultrasonic cleaning device is continuously applied with ultrasonic waves.

[0075] Table 1 is a table of electrochemical performance of soft package lithium batteries of different examples

[0076]

[0077]

[0078] From the above table, it can be seen that in Comparative Example 1, the electrolyte immersion time is short, there is no ultrasonic effect, and the electrolyte effect is poor. In Comparative Example 4, the effect of the ultrasonic cleaner is also poor. The first cycle discharge capacity, the first cycle charge-discharge efficiency and the battery capacity retention rate after 300 cycles of the soft-pack lithium battery in Comparative Examples 1 and 4 are all relatively low. In Examples 1-6, the electrolyte is subjected to ultrasonic vibration, and in the case of a short electrolyte immersion time, the first cycle discharge capacity, the first cycle charge-discharge efficiency and the battery capacity retention rate after 300 cycles are all significantly improved compared with Comparative Examples 1 and 4, and the electrochemical performance of the battery is comparable to that of the effect of standing for 48 hours (Comparative Example 2 and Comparative Example 3). It can be seen that the soft-pack lithium battery electrolyte immersion device and method provided in the embodiments of the present application can effectively shorten the electrolyte immersion time by using ultrasonic vibration to immerse the electrolyte, and can also enable the soft-pack lithium battery to maintain good electrochemical performance.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions described in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalent ones; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A soft-pack lithium battery electrolyte wetting device, characterized in that, include: Ultrasonic system; A guide rod, the first end of which is retractably connected to the ultrasonic system, the guide rod being used to transmit ultrasonic waves; The clamp includes a pair of clamping plates, a soft-pack lithium battery is clamped between the pair of clamping plates, and the second end of the guide rod is telescopically connected to one of the clamping plates to adjust the distance between the pair of clamping plates; A stress detection plate is sandwiched between a pair of clamping plates and stacked with the soft-pack lithium battery. The stress detection plate is used to detect the clamping force of the clamp on the soft-pack lithium battery.

2. The soft-pack lithium battery electrolyte wetting device according to claim 1, characterized in that, It also includes a stepper controller, which is connected to the guide rod and is used to adjust the distance between the ultrasonic system and the clamp.

3. The soft-pack lithium battery electrolyte wetting device according to claim 1, characterized in that, The frequency of the ultrasonic system is 10-100kHz, and the working time of the ultrasonic system is 5-120min.

4. The soft-pack lithium battery electrolyte wetting device according to claim 1, characterized in that, It also includes a fixing component, which includes: A fixed bracket, which is connected to the ultrasonic system via a fastener; The base is connected to the fixed bracket.

5. A method for impregnating a soft-pack lithium battery electrolyte using the impregnation device according to any one of claims 1-4, characterized in that, include: The soft-pack lithium battery is clamped within a pair of clamping plates; The working time of the ultrasonic system is controlled to meet a preset threshold so that the ultrasonic waves generated by the ultrasonic system act on the soft-pack lithium battery to wet the soft-pack lithium battery.

6. The method for impregnating a soft-pack lithium battery with electrolyte according to claim 5, characterized in that, The method further includes: The ultrasonic system is controlled to operate in either continuous or intermittent mode.

7. The method for impregnating a soft-pack lithium battery with electrolyte according to claim 6, characterized in that, The step of controlling the ultrasonic system to operate in an intermittent mode further includes: The duration of operation and the duration of shutdown of the ultrasonic system are controlled to be equal each time.

8. The method for impregnating a soft-pack lithium battery with electrolyte according to claim 6, characterized in that, Prior to the step of clamping the pouch lithium battery within the pair of clamping plates, the method further includes: The dry cell is placed into an aluminum-plastic film, and the aluminum-plastic film is sealed on three sides, with the remaining side open as a liquid injection port, and the dry cell is dried. Electrolyte is injected into the dry cell through the injection port. After the dry cell is left to stand under vacuum for a preset time, the injection port is sealed.

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